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Merge branch 'netfs-writeback' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

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Pull netfs writeback updates from David Howells:

The primary purpose of these patches is to rework the netfslib writeback
implementation such that pages read from the cache are written to the cache
through ->writepages(), thereby allowing the fscache page flag to be
retired.

The reworking also:

 (1) builds on top of the new writeback_iter() infrastructure;

 (2) makes it possible to use vectored write RPCs as discontiguous streams
     of pages can be accommodated;

 (3) makes it easier to do simultaneous content crypto and stream division.

 (4) provides support for retrying writes and re-dividing a stream;

 (5) replaces the ->launder_folio() op, so that ->writepages() is used
     instead;

 (6) uses mempools to allocate the netfs_io_request and netfs_io_subrequest
     structs to avoid allocation failure in the writeback path.

Some code that uses the fscache page flag is retained for compatibility
purposes with nfs and ceph.  The code is switched to using the synonymous
private_2 label instead and marked with deprecation comments.  I have a
separate set of patches that convert cifs to use this code.

-~-

In this new implementation, writeback_iter() is used to pump folios,
progressively creating two parallel, but separate streams.  Either or both
streams can contain gaps, and the subrequests in each stream can be of
variable size, don't need to align with each other and don't need to align
with the folios.  (Note that more streams can be added if we have multiple
servers to duplicate data to).

Indeed, subrequests can cross folio boundaries, may cover several folios or
a folio may be spanned by multiple subrequests, e.g.:

         +---+---+-----+-----+---+----------+
Folios:  |   |   |     |     |   |          |
         +---+---+-----+-----+---+----------+

           +------+------+     +----+----+
Upload:    |      |      |.....|    |    |
           +------+------+     +----+----+

         +------+------+------+------+------+
Cache:   |      |      |      |      |      |
         +------+------+------+------+------+

Data that got read from the server that needs copying to the cache is
stored in folios that are marked dirty and have folio->private set to a
special value.

The progressive subrequest construction permits the algorithm to be
preparing both the next upload to the server and the next write to the
cache whilst the previous ones are already in progress.  Throttling can be
applied to control the rate of production of subrequests - and, in any
case, we probably want to write them to the server in ascending order,
particularly if the file will be extended.

Content crypto can also be prepared at the same time as the subrequests and
run asynchronously, with the prepped requests being stalled until the
crypto catches up with them.  This might also be useful for transport
crypto, but that happens at a lower layer, so probably would be harder to
pull off.

The algorithm is split into three parts:

 (1) The issuer.  This walks through the data, packaging it up, encrypting
     it and creating subrequests.  The part of this that generates
     subrequests only deals with file positions and spans and so is usable
     for DIO/unbuffered writes as well as buffered writes.

 (2) The collector.  This asynchronously collects completed subrequests,
     unlocks folios, frees crypto buffers and performs any retries.  This
     runs in a work queue so that the issuer can return to the caller for
     writeback (so that the VM can have its kswapd thread back) or async
     writes.

     Collection is slightly complex as the collector has to work out where
     discontiguities happen in the folio list so that it doesn't try and
     collect folios that weren't included in the write out.

 (3) The retryer.  This pauses the issuer, waits for all outstanding
     subrequests to complete and then goes through the failed subrequests
     to reissue them.  This may involve reprepping them (with cifs, the
     credits must be renegotiated and a subrequest may need splitting), and
     doing RMW for content crypto if there's a conflicting change on the
     server.

* 'netfs-writeback' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (22 commits)
  netfs, afs: Use writeback retry to deal with alternate keys
  netfs: Miscellaneous tidy ups
  netfs: Remove the old writeback code
  netfs: Cut over to using new writeback code
  netfs, cachefiles: Implement helpers for new write code
  netfs, 9p: Implement helpers for new write code
  netfs, afs: Implement helpers for new write code
  netfs: Add some write-side stats and clean up some stat names
  netfs: New writeback implementation
  netfs: Switch to using unsigned long long rather than loff_t
  mm: Export writeback_iter()
  netfs: Use mempools for allocating requests and subrequests
  netfs: Remove ->launder_folio() support
  afs: Use alternative invalidation to using launder_folio
  9p: Use alternative invalidation to using launder_folio
  mm: Provide a means of invalidation without using launder_folio
  netfs: Use subreq_counter to allocate subreq debug_index values
  netfs: Make netfs_io_request::subreq_counter an atomic_t
  netfs: Remove deprecated use of PG_private_2 as a second writeback flag
  mm: Remove the PG_fscache alias for PG_private_2
  ...

Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2024-05-02 11:20:38 +02:00
commit 3931e678fb
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
35 changed files with 2516 additions and 1762 deletions
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66
fs/9p/vfs_addr.c
View File

@ -26,38 +26,40 @@
#include "cache.h"
#include "fid.h"
static void v9fs_upload_to_server(struct netfs_io_subrequest *subreq)
/*
* Writeback calls this when it finds a folio that needs uploading. This isn't
* called if writeback only has copy-to-cache to deal with.
*/
static void v9fs_begin_writeback(struct netfs_io_request *wreq)
{
struct p9_fid *fid;
fid = v9fs_fid_find_inode(wreq->inode, true, INVALID_UID, true);
if (!fid) {
WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
wreq->inode->i_ino);
return;
}
wreq->wsize = fid->clnt->msize - P9_IOHDRSZ;
if (fid->iounit)
wreq->wsize = min(wreq->wsize, fid->iounit);
wreq->netfs_priv = fid;
wreq->io_streams[0].avail = true;
}
/*
* Issue a subrequest to write to the server.
*/
static void v9fs_issue_write(struct netfs_io_subrequest *subreq)
{
struct p9_fid *fid = subreq->rreq->netfs_priv;
int err, len;
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);
netfs_write_subrequest_terminated(subreq, len ?: err, false);
}
static void v9fs_upload_to_server_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq =
container_of(work, struct netfs_io_subrequest, work);
v9fs_upload_to_server(subreq);
}
/*
* Set up write requests for a writeback slice. We need to add a write request
* for each write we want to make.
*/
static void v9fs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
{
struct netfs_io_subrequest *subreq;
subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
start, len, v9fs_upload_to_server_worker);
if (subreq)
netfs_queue_write_request(subreq);
}
/**
* v9fs_issue_read - Issue a read from 9P
* @subreq: The read to make
@ -87,12 +89,16 @@ static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
{
struct p9_fid *fid;
bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||
rreq->origin == NETFS_WRITEBACK ||
rreq->origin == NETFS_WRITETHROUGH ||
rreq->origin == NETFS_LAUNDER_WRITE ||
rreq->origin == NETFS_UNBUFFERED_WRITE ||
rreq->origin == NETFS_DIO_WRITE);
if (rreq->origin == NETFS_WRITEBACK)
return 0; /* We don't get the write handle until we find we
* have actually dirty data and not just
* copy-to-cache data.
*/
if (file) {
fid = file->private_data;
if (!fid)
@ -104,6 +110,10 @@ static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
goto no_fid;
}
rreq->wsize = fid->clnt->msize - P9_IOHDRSZ;
if (fid->iounit)
rreq->wsize = min(rreq->wsize, fid->iounit);
/* we might need to read from a fid that was opened write-only
* for read-modify-write of page cache, use the writeback fid
* for that */
@ -132,7 +142,8 @@ const struct netfs_request_ops v9fs_req_ops = {
.init_request = v9fs_init_request,
.free_request = v9fs_free_request,
.issue_read = v9fs_issue_read,
.create_write_requests = v9fs_create_write_requests,
.begin_writeback = v9fs_begin_writeback,
.issue_write = v9fs_issue_write,
};
const struct address_space_operations v9fs_addr_operations = {
@ -141,7 +152,6 @@ const struct address_space_operations v9fs_addr_operations = {
.dirty_folio = netfs_dirty_folio,
.release_folio = netfs_release_folio,
.invalidate_folio = netfs_invalidate_folio,
.launder_folio = netfs_launder_folio,
.direct_IO = noop_direct_IO,
.writepages = netfs_writepages,
};

8
fs/afs/file.c
View File

@ -54,7 +54,6 @@ const struct address_space_operations afs_file_aops = {
.read_folio = netfs_read_folio,
.readahead = netfs_readahead,
.dirty_folio = netfs_dirty_folio,
.launder_folio = netfs_launder_folio,
.release_folio = netfs_release_folio,
.invalidate_folio = netfs_invalidate_folio,
.migrate_folio = filemap_migrate_folio,
@ -354,7 +353,7 @@ static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
if (file)
rreq->netfs_priv = key_get(afs_file_key(file));
rreq->rsize = 256 * 1024;
rreq->wsize = 256 * 1024;
rreq->wsize = 256 * 1024 * 1024;
return 0;
}
@ -369,6 +368,7 @@ static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
static void afs_free_request(struct netfs_io_request *rreq)
{
key_put(rreq->netfs_priv);
afs_put_wb_key(rreq->netfs_priv2);
}
static void afs_update_i_size(struct inode *inode, loff_t new_i_size)
@ -400,7 +400,9 @@ const struct netfs_request_ops afs_req_ops = {
.issue_read = afs_issue_read,
.update_i_size = afs_update_i_size,
.invalidate_cache = afs_netfs_invalidate_cache,
.create_write_requests = afs_create_write_requests,
.begin_writeback = afs_begin_writeback,
.prepare_write = afs_prepare_write,
.issue_write = afs_issue_write,
};
static void afs_add_open_mmap(struct afs_vnode *vnode)

6
fs/afs/internal.h
View File

@ -916,7 +916,6 @@ struct afs_operation {
loff_t pos;
loff_t size;
loff_t i_size;
bool laundering; /* Laundering page, PG_writeback not set */
} store;
struct {
struct iattr *attr;
@ -1599,11 +1598,14 @@ extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *);
/*
* write.c
*/
void afs_prepare_write(struct netfs_io_subrequest *subreq);
void afs_issue_write(struct netfs_io_subrequest *subreq);
void afs_begin_writeback(struct netfs_io_request *wreq);
void afs_retry_request(struct netfs_io_request *wreq, struct netfs_io_stream *stream);
extern int afs_writepages(struct address_space *, struct writeback_control *);
extern int afs_fsync(struct file *, loff_t, loff_t, int);
extern vm_fault_t afs_page_mkwrite(struct vm_fault *vmf);
extern void afs_prune_wb_keys(struct afs_vnode *);
void afs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len);
/*
* xattr.c

4
fs/afs/validation.c
View File

@ -365,9 +365,9 @@ static void afs_zap_data(struct afs_vnode *vnode)
* written back in a regular file and completely discard the pages in a
* directory or symlink */
if (S_ISREG(vnode->netfs.inode.i_mode))
invalidate_remote_inode(&vnode->netfs.inode);
filemap_invalidate_inode(&vnode->netfs.inode, true, 0, LLONG_MAX);
else
invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
filemap_invalidate_inode(&vnode->netfs.inode, false, 0, LLONG_MAX);
}
/*

193
fs/afs/write.c
View File

@ -29,43 +29,39 @@ static void afs_pages_written_back(struct afs_vnode *vnode, loff_t start, unsign
/*
* Find a key to use for the writeback. We cached the keys used to author the
* writes on the vnode. *_wbk will contain the last writeback key used or NULL
* and we need to start from there if it's set.
* writes on the vnode. wreq->netfs_priv2 will contain the last writeback key
* record used or NULL and we need to start from there if it's set.
* wreq->netfs_priv will be set to the key itself or NULL.
*/
static int afs_get_writeback_key(struct afs_vnode *vnode,
struct afs_wb_key **_wbk)
static void afs_get_writeback_key(struct netfs_io_request *wreq)
{
struct afs_wb_key *wbk = NULL;
struct list_head *p;
int ret = -ENOKEY, ret2;
struct afs_wb_key *wbk, *old = wreq->netfs_priv2;
struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
key_put(wreq->netfs_priv);
wreq->netfs_priv = NULL;
wreq->netfs_priv2 = NULL;
spin_lock(&vnode->wb_lock);
if (*_wbk)
p = (*_wbk)->vnode_link.next;
if (old)
wbk = list_next_entry(old, vnode_link);
else
p = vnode->wb_keys.next;
wbk = list_first_entry(&vnode->wb_keys, struct afs_wb_key, vnode_link);
while (p != &vnode->wb_keys) {
wbk = list_entry(p, struct afs_wb_key, vnode_link);
list_for_each_entry_from(wbk, &vnode->wb_keys, vnode_link) {
_debug("wbk %u", key_serial(wbk->key));
ret2 = key_validate(wbk->key);
if (ret2 == 0) {
if (key_validate(wbk->key) == 0) {
refcount_inc(&wbk->usage);
wreq->netfs_priv = key_get(wbk->key);
wreq->netfs_priv2 = wbk;
_debug("USE WB KEY %u", key_serial(wbk->key));
break;
}
wbk = NULL;
if (ret == -ENOKEY)
ret = ret2;
p = p->next;
}
spin_unlock(&vnode->wb_lock);
if (*_wbk)
afs_put_wb_key(*_wbk);
*_wbk = wbk;
return 0;
afs_put_wb_key(old);
}
static void afs_store_data_success(struct afs_operation *op)
@ -75,8 +71,7 @@ static void afs_store_data_success(struct afs_operation *op)
op->ctime = op->file[0].scb.status.mtime_client;
afs_vnode_commit_status(op, &op->file[0]);
if (!afs_op_error(op)) {
if (!op->store.laundering)
afs_pages_written_back(vnode, op->store.pos, op->store.size);
afs_pages_written_back(vnode, op->store.pos, op->store.size);
afs_stat_v(vnode, n_stores);
atomic_long_add(op->store.size, &afs_v2net(vnode)->n_store_bytes);
}
@ -89,113 +84,125 @@ static const struct afs_operation_ops afs_store_data_operation = {
};
/*
* write to a file
* Prepare a subrequest to write to the server. This sets the max_len
* parameter.
*/
static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter, loff_t pos,
bool laundering)
void afs_prepare_write(struct netfs_io_subrequest *subreq)
{
//if (test_bit(NETFS_SREQ_RETRYING, &subreq->flags))
// subreq->max_len = 512 * 1024;
//else
subreq->max_len = 256 * 1024 * 1024;
}
/*
* Issue a subrequest to write to the server.
*/
static void afs_issue_write_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq = container_of(work, struct netfs_io_subrequest, work);
struct netfs_io_request *wreq = subreq->rreq;
struct afs_operation *op;
struct afs_wb_key *wbk = NULL;
loff_t size = iov_iter_count(iter);
struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
unsigned long long pos = subreq->start + subreq->transferred;
size_t len = subreq->len - subreq->transferred;
int ret = -ENOKEY;
_enter("%s{%llx:%llu.%u},%llx,%llx",
_enter("R=%x[%x],%s{%llx:%llu.%u},%llx,%zx",
wreq->debug_id, subreq->debug_index,
vnode->volume->name,
vnode->fid.vid,
vnode->fid.vnode,
vnode->fid.unique,
size, pos);
pos, len);
ret = afs_get_writeback_key(vnode, &wbk);
if (ret) {
_leave(" = %d [no keys]", ret);
return ret;
}
#if 0 // Error injection
if (subreq->debug_index == 3)
return netfs_write_subrequest_terminated(subreq, -ENOANO, false);
op = afs_alloc_operation(wbk->key, vnode->volume);
if (IS_ERR(op)) {
afs_put_wb_key(wbk);
return -ENOMEM;
if (!test_bit(NETFS_SREQ_RETRYING, &subreq->flags)) {
set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
return netfs_write_subrequest_terminated(subreq, -EAGAIN, false);
}
#endif
op = afs_alloc_operation(wreq->netfs_priv, vnode->volume);
if (IS_ERR(op))
return netfs_write_subrequest_terminated(subreq, -EAGAIN, false);
afs_op_set_vnode(op, 0, vnode);
op->file[0].dv_delta = 1;
op->file[0].dv_delta = 1;
op->file[0].modification = true;
op->store.pos = pos;
op->store.size = size;
op->store.laundering = laundering;
op->flags |= AFS_OPERATION_UNINTR;
op->ops = &afs_store_data_operation;
op->store.pos = pos;
op->store.size = len;
op->flags |= AFS_OPERATION_UNINTR;
op->ops = &afs_store_data_operation;
try_next_key:
afs_begin_vnode_operation(op);
op->store.write_iter = iter;
op->store.i_size = max(pos + size, vnode->netfs.remote_i_size);
op->mtime = inode_get_mtime(&vnode->netfs.inode);
op->store.write_iter = &subreq->io_iter;
op->store.i_size = umax(pos + len, vnode->netfs.remote_i_size);
op->mtime = inode_get_mtime(&vnode->netfs.inode);
afs_wait_for_operation(op);
switch (afs_op_error(op)) {
ret = afs_put_operation(op);
switch (ret) {
case -EACCES:
case -EPERM:
case -ENOKEY:
case -EKEYEXPIRED:
case -EKEYREJECTED:
case -EKEYREVOKED:
_debug("next");
ret = afs_get_writeback_key(vnode, &wbk);
if (ret == 0) {
key_put(op->key);
op->key = key_get(wbk->key);
goto try_next_key;
}
/* If there are more keys we can try, use the retry algorithm
* to rotate the keys.
*/
if (wreq->netfs_priv2)
set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
break;
}
afs_put_wb_key(wbk);
_leave(" = %d", afs_op_error(op));
return afs_put_operation(op);
netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len, false);
}
static void afs_upload_to_server(struct netfs_io_subrequest *subreq)
void afs_issue_write(struct netfs_io_subrequest *subreq)
{
struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
ssize_t ret;
_enter("%x[%x],%zx",
subreq->rreq->debug_id, subreq->debug_index, subreq->io_iter.count);
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
ret = afs_store_data(vnode, &subreq->io_iter, subreq->start,
subreq->rreq->origin == NETFS_LAUNDER_WRITE);
netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len,
false);
}
static void afs_upload_to_server_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq =
container_of(work, struct netfs_io_subrequest, work);
afs_upload_to_server(subreq);
subreq->work.func = afs_issue_write_worker;
if (!queue_work(system_unbound_wq, &subreq->work))
WARN_ON_ONCE(1);
}
/*
* Set up write requests for a writeback slice. We need to add a write request
* for each write we want to make.
* Writeback calls this when it finds a folio that needs uploading. This isn't
* called if writeback only has copy-to-cache to deal with.
*/
void afs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
void afs_begin_writeback(struct netfs_io_request *wreq)
{
struct netfs_io_subrequest *subreq;
afs_get_writeback_key(wreq);
wreq->io_streams[0].avail = true;
}
_enter("%x,%llx-%llx", wreq->debug_id, start, start + len);
/*
* Prepare to retry the writes in request. Use this to try rotating the
* available writeback keys.
*/
void afs_retry_request(struct netfs_io_request *wreq, struct netfs_io_stream *stream)
{
struct netfs_io_subrequest *subreq =
list_first_entry(&stream->subrequests,
struct netfs_io_subrequest, rreq_link);
subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
start, len, afs_upload_to_server_worker);
if (subreq)
netfs_queue_write_request(subreq);
switch (subreq->error) {
case -EACCES:
case -EPERM:
case -ENOKEY:
case -EKEYEXPIRED:
case -EKEYREJECTED:
case -EKEYREVOKED:
afs_get_writeback_key(wreq);
if (!wreq->netfs_priv)
stream->failed = true;
break;
}
}
/*

76
fs/cachefiles/io.c
View File

@ -9,6 +9,7 @@
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/uio.h>
#include <linux/bio.h>
#include <linux/falloc.h>
#include <linux/sched/mm.h>
#include <trace/events/fscache.h>
@ -493,7 +494,7 @@ out_no_object:
* boundary as appropriate.
*/
static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq,
loff_t i_size)
unsigned long long i_size)
{
return cachefiles_do_prepare_read(&subreq->rreq->cache_resources,
subreq->start, &subreq->len, i_size,
@ -622,6 +623,77 @@ static int cachefiles_prepare_write(struct netfs_cache_resources *cres,
return ret;
}
static void cachefiles_prepare_write_subreq(struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *wreq = subreq->rreq;
struct netfs_cache_resources *cres = &wreq->cache_resources;
_enter("W=%x[%x] %llx", wreq->debug_id, subreq->debug_index, subreq->start);
subreq->max_len = ULONG_MAX;
subreq->max_nr_segs = BIO_MAX_VECS;
if (!cachefiles_cres_file(cres)) {
if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE))
return netfs_prepare_write_failed(subreq);
if (!cachefiles_cres_file(cres))
return netfs_prepare_write_failed(subreq);
}
}
static void cachefiles_issue_write(struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *wreq = subreq->rreq;
struct netfs_cache_resources *cres = &wreq->cache_resources;
struct cachefiles_object *object = cachefiles_cres_object(cres);
struct cachefiles_cache *cache = object->volume->cache;
const struct cred *saved_cred;
size_t off, pre, post, len = subreq->len;
loff_t start = subreq->start;
int ret;
_enter("W=%x[%x] %llx-%llx",
wreq->debug_id, subreq->debug_index, start, start + len - 1);
/* We need to start on the cache granularity boundary */
off = start & (CACHEFILES_DIO_BLOCK_SIZE - 1);
if (off) {
pre = CACHEFILES_DIO_BLOCK_SIZE - off;
if (pre >= len) {
netfs_write_subrequest_terminated(subreq, len, false);
return;
}
subreq->transferred += pre;
start += pre;
len -= pre;
iov_iter_advance(&subreq->io_iter, pre);
}
/* We also need to end on the cache granularity boundary */
post = len & (CACHEFILES_DIO_BLOCK_SIZE - 1);
if (post) {
len -= post;
if (len == 0) {
netfs_write_subrequest_terminated(subreq, post, false);
return;
}
iov_iter_truncate(&subreq->io_iter, len);
}
cachefiles_begin_secure(cache, &saved_cred);
ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres),
&start, &len, len, true);
cachefiles_end_secure(cache, saved_cred);
if (ret < 0) {
netfs_write_subrequest_terminated(subreq, ret, false);
return;
}
cachefiles_write(&subreq->rreq->cache_resources,
subreq->start, &subreq->io_iter,
netfs_write_subrequest_terminated, subreq);
}
/*
* Clean up an operation.
*/
@ -638,8 +710,10 @@ static const struct netfs_cache_ops cachefiles_netfs_cache_ops = {
.end_operation = cachefiles_end_operation,
.read = cachefiles_read,
.write = cachefiles_write,
.issue_write = cachefiles_issue_write,
.prepare_read = cachefiles_prepare_read,
.prepare_write = cachefiles_prepare_write,
.prepare_write_subreq = cachefiles_prepare_write_subreq,
.prepare_ondemand_read = cachefiles_prepare_ondemand_read,
.query_occupancy = cachefiles_query_occupancy,
};

24
fs/ceph/addr.c
View File

@ -193,7 +193,7 @@ static void ceph_netfs_expand_readahead(struct netfs_io_request *rreq)
* block, but do not exceed the file size, unless the original
* request already exceeds it.
*/
new_end = min(round_up(end, lo->stripe_unit), rreq->i_size);
new_end = umin(round_up(end, lo->stripe_unit), rreq->i_size);
if (new_end > end && new_end <= rreq->start + max_len)
rreq->len = new_end - rreq->start;
@ -498,11 +498,6 @@ const struct netfs_request_ops ceph_netfs_ops = {
};
#ifdef CONFIG_CEPH_FSCACHE
static void ceph_set_page_fscache(struct page *page)
{
set_page_fscache(page);
}
static void ceph_fscache_write_terminated(void *priv, ssize_t error, bool was_async)
{
struct inode *inode = priv;
@ -517,13 +512,9 @@ static void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, b
struct fscache_cookie *cookie = ceph_fscache_cookie(ci);
fscache_write_to_cache(cookie, inode->i_mapping, off, len, i_size_read(inode),
ceph_fscache_write_terminated, inode, caching);
ceph_fscache_write_terminated, inode, true, caching);
}
#else
static inline void ceph_set_page_fscache(struct page *page)
{
}
static inline void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, bool caching)
{
}
@ -715,8 +706,6 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
len = wlen;
set_page_writeback(page);
if (caching)
ceph_set_page_fscache(page);
ceph_fscache_write_to_cache(inode, page_off, len, caching);
if (IS_ENCRYPTED(inode)) {
@ -800,8 +789,6 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
return AOP_WRITEPAGE_ACTIVATE;
}
wait_on_page_fscache(page);
err = writepage_nounlock(page, wbc);
if (err == -ERESTARTSYS) {
/* direct memory reclaimer was killed by SIGKILL. return 0
@ -1075,7 +1062,7 @@ get_more_pages:
unlock_page(page);
break;
}
if (PageWriteback(page) || PageFsCache(page)) {
if (PageWriteback(page)) {
if (wbc->sync_mode == WB_SYNC_NONE) {
doutc(cl, "%p under writeback\n", page);
unlock_page(page);
@ -1083,7 +1070,6 @@ get_more_pages:
}
doutc(cl, "waiting on writeback %p\n", page);
wait_on_page_writeback(page);
wait_on_page_fscache(page);
}
if (!clear_page_dirty_for_io(page)) {
@ -1268,8 +1254,6 @@ new_request:
}
set_page_writeback(page);
if (caching)
ceph_set_page_fscache(page);
len += thp_size(page);
}
ceph_fscache_write_to_cache(inode, offset, len, caching);
@ -1513,7 +1497,7 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
if (r < 0)
return r;
folio_wait_fscache(folio);
folio_wait_private_2(folio); /* [DEPRECATED] */
WARN_ON_ONCE(!folio_test_locked(folio));
*pagep = &folio->page;
return 0;

2
fs/ceph/inode.c
View File

@ -577,6 +577,8 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
/* Set parameters for the netfs library */
netfs_inode_init(&ci->netfs, &ceph_netfs_ops, false);
/* [DEPRECATED] Use PG_private_2 to mark folio being written to the cache. */
__set_bit(NETFS_ICTX_USE_PGPRIV2, &ci->netfs.flags);
spin_lock_init(&ci->i_ceph_lock);

3
fs/netfs/Makefile
View File

@ -11,7 +11,8 @@ netfs-y := \
main.o \
misc.o \
objects.o \
output.o
write_collect.o \
write_issue.o
netfs-$(CONFIG_NETFS_STATS) += stats.o

40
fs/netfs/buffered_read.c
View File

@ -10,8 +10,11 @@
#include "internal.h"
/*
* Unlock the folios in a read operation. We need to set PG_fscache on any
* Unlock the folios in a read operation. We need to set PG_writeback on any
* folios we're going to write back before we unlock them.
*
* Note that if the deprecated NETFS_RREQ_USE_PGPRIV2 is set then we use
* PG_private_2 and do a direct write to the cache from here instead.
*/
void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
{
@ -48,14 +51,14 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
xas_for_each(&xas, folio, last_page) {
loff_t pg_end;
bool pg_failed = false;
bool folio_started;
bool wback_to_cache = false;
bool folio_started = false;
if (xas_retry(&xas, folio))
continue;
pg_end = folio_pos(folio) + folio_size(folio) - 1;
folio_started = false;
for (;;) {
loff_t sreq_end;
@ -63,10 +66,16 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
pg_failed = true;
break;
}
if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
folio_start_fscache(folio);
folio_started = true;
if (test_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags)) {
if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE,
&subreq->flags)) {
trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
folio_start_private_2(folio);
folio_started = true;
}
} else {
wback_to_cache |=
test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
}
pg_failed |= subreq_failed;
sreq_end = subreq->start + subreq->len - 1;
@ -98,6 +107,11 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
kfree(finfo);
}
folio_mark_uptodate(folio);
if (wback_to_cache && !WARN_ON_ONCE(folio_get_private(folio) != NULL)) {
trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
folio_attach_private(folio, NETFS_FOLIO_COPY_TO_CACHE);
filemap_dirty_folio(folio->mapping, folio);
}
}
if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) {
@ -116,7 +130,9 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
}
static void netfs_cache_expand_readahead(struct netfs_io_request *rreq,
loff_t *_start, size_t *_len, loff_t i_size)
unsigned long long *_start,
unsigned long long *_len,
unsigned long long i_size)
{
struct netfs_cache_resources *cres = &rreq->cache_resources;
@ -266,7 +282,7 @@ int netfs_read_folio(struct file *file, struct folio *folio)
if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
goto discard;
netfs_stat(&netfs_n_rh_readpage);
netfs_stat(&netfs_n_rh_read_folio);
trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
/* Set up the output buffer */
@ -450,7 +466,7 @@ retry:
if (!netfs_is_cache_enabled(ctx) &&
netfs_skip_folio_read(folio, pos, len, false)) {
netfs_stat(&netfs_n_rh_write_zskip);
goto have_folio_no_wait;
goto have_folio;
}
rreq = netfs_alloc_request(mapping, file,
@ -491,10 +507,6 @@ retry:
netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
have_folio:
ret = folio_wait_fscache_killable(folio);
if (ret < 0)
goto error;
have_folio_no_wait:
*_folio = folio;
_leave(" = 0");
return 0;

825
fs/netfs/buffered_write.c
View File

@ -1,5 +1,5 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Network filesystem high-level write support.
/* Network filesystem high-level buffered write support.
*
* Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
@ -26,25 +26,15 @@ enum netfs_how_to_modify {
NETFS_FLUSH_CONTENT, /* Flush incompatible content. */
};
static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq);
static void netfs_set_group(struct folio *folio, struct netfs_group *netfs_group)
{
if (netfs_group && !folio_get_private(folio))
folio_attach_private(folio, netfs_get_group(netfs_group));
}
void *priv = folio_get_private(folio);
#if IS_ENABLED(CONFIG_FSCACHE)
static void netfs_folio_start_fscache(bool caching, struct folio *folio)
{
if (caching)
folio_start_fscache(folio);
if (netfs_group && (!priv || priv == NETFS_FOLIO_COPY_TO_CACHE))
folio_attach_private(folio, netfs_get_group(netfs_group));
else if (!netfs_group && priv == NETFS_FOLIO_COPY_TO_CACHE)
folio_detach_private(folio);
}
#else
static void netfs_folio_start_fscache(bool caching, struct folio *folio)
{
}
#endif
/*
* Decide how we should modify a folio. We might be attempting to do
@ -63,11 +53,12 @@ static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx,
bool maybe_trouble)
{
struct netfs_folio *finfo = netfs_folio_info(folio);
struct netfs_group *group = netfs_folio_group(folio);
loff_t pos = folio_file_pos(folio);
_enter("");
if (netfs_folio_group(folio) != netfs_group)
if (group != netfs_group && group != NETFS_FOLIO_COPY_TO_CACHE)
return NETFS_FLUSH_CONTENT;
if (folio_test_uptodate(folio))
@ -81,16 +72,12 @@ static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx,
if (file->f_mode & FMODE_READ)
goto no_write_streaming;
if (test_bit(NETFS_ICTX_NO_WRITE_STREAMING, &ctx->flags))
goto no_write_streaming;
if (netfs_is_cache_enabled(ctx)) {
/* We don't want to get a streaming write on a file that loses
* caching service temporarily because the backing store got
* culled.
*/
if (!test_bit(NETFS_ICTX_NO_WRITE_STREAMING, &ctx->flags))
set_bit(NETFS_ICTX_NO_WRITE_STREAMING, &ctx->flags);
goto no_write_streaming;
}
@ -130,6 +117,37 @@ static struct folio *netfs_grab_folio_for_write(struct address_space *mapping,
mapping_gfp_mask(mapping));
}
/*
* Update i_size and estimate the update to i_blocks to reflect the additional
* data written into the pagecache until we can find out from the server what
* the values actually are.
*/
static void netfs_update_i_size(struct netfs_inode *ctx, struct inode *inode,
loff_t i_size, loff_t pos, size_t copied)
{
blkcnt_t add;
size_t gap;
if (ctx->ops->update_i_size) {
ctx->ops->update_i_size(inode, pos);
return;
}
i_size_write(inode, pos);
#if IS_ENABLED(CONFIG_FSCACHE)
fscache_update_cookie(ctx->cache, NULL, &pos);
#endif
gap = SECTOR_SIZE - (i_size & (SECTOR_SIZE - 1));
if (copied > gap) {
add = DIV_ROUND_UP(copied - gap, SECTOR_SIZE);
inode->i_blocks = min_t(blkcnt_t,
DIV_ROUND_UP(pos, SECTOR_SIZE),
inode->i_blocks + add);
}
}
/**
* netfs_perform_write - Copy data into the pagecache.
* @iocb: The operation parameters
@ -160,7 +178,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
};
struct netfs_io_request *wreq = NULL;
struct netfs_folio *finfo;
struct folio *folio;
struct folio *folio, *writethrough = NULL;
enum netfs_how_to_modify howto;
enum netfs_folio_trace trace;
unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC;
@ -189,7 +207,9 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
}
if (!is_sync_kiocb(iocb))
wreq->iocb = iocb;
wreq->cleanup = netfs_cleanup_buffered_write;
netfs_stat(&netfs_n_wh_writethrough);
} else {
netfs_stat(&netfs_n_wh_buffered_write);
}
do {
@ -230,6 +250,16 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
offset = pos & (flen - 1);
part = min_t(size_t, flen - offset, part);
/* Wait for writeback to complete. The writeback engine owns
* the info in folio->private and may change it until it
* removes the WB mark.
*/
if (folio_get_private(folio) &&
folio_wait_writeback_killable(folio)) {
ret = written ? -EINTR : -ERESTARTSYS;
goto error_folio_unlock;
}
if (signal_pending(current)) {
ret = written ? -EINTR : -ERESTARTSYS;
goto error_folio_unlock;
@ -304,6 +334,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
maybe_trouble = true;
iov_iter_revert(iter, copied);
copied = 0;
folio_unlock(folio);
goto retry;
}
netfs_set_group(folio, netfs_group);
@ -351,41 +382,22 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
trace_netfs_folio(folio, trace);
/* Update the inode size if we moved the EOF marker */
i_size = i_size_read(inode);
pos += copied;
if (pos > i_size) {
if (ctx->ops->update_i_size) {
ctx->ops->update_i_size(inode, pos);
} else {
i_size_write(inode, pos);
#if IS_ENABLED(CONFIG_FSCACHE)
fscache_update_cookie(ctx->cache, NULL, &pos);
#endif
}
}
i_size = i_size_read(inode);
if (pos > i_size)
netfs_update_i_size(ctx, inode, i_size, pos, copied);
written += copied;
if (likely(!wreq)) {
folio_mark_dirty(folio);
folio_unlock(folio);
} else {
if (folio_test_dirty(folio))
/* Sigh. mmap. */
folio_clear_dirty_for_io(folio);
/* We make multiple writes to the folio... */
if (!folio_test_writeback(folio)) {
folio_wait_fscache(folio);
folio_start_writeback(folio);
folio_start_fscache(folio);
if (wreq->iter.count == 0)
trace_netfs_folio(folio, netfs_folio_trace_wthru);
else
trace_netfs_folio(folio, netfs_folio_trace_wthru_plus);
}
netfs_advance_writethrough(wreq, copied,
offset + copied == flen);
netfs_advance_writethrough(wreq, &wbc, folio, copied,
offset + copied == flen,
&writethrough);
/* Folio unlocked */
}
retry:
folio_unlock(folio);
folio_put(folio);
folio = NULL;
@ -394,7 +406,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
out:
if (unlikely(wreq)) {
ret2 = netfs_end_writethrough(wreq, iocb);
ret2 = netfs_end_writethrough(wreq, &wbc, writethrough);
wbc_detach_inode(&wbc);
if (ret2 == -EIOCBQUEUED)
return ret2;
@ -505,6 +517,7 @@ EXPORT_SYMBOL(netfs_file_write_iter);
*/
vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group)
{
struct netfs_group *group;
struct folio *folio = page_folio(vmf->page);
struct file *file = vmf->vma->vm_file;
struct inode *inode = file_inode(file);
@ -515,19 +528,22 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
sb_start_pagefault(inode->i_sb);
if (folio_wait_writeback_killable(folio))
goto out;
if (folio_lock_killable(folio) < 0)
goto out;
if (folio_wait_writeback_killable(folio)) {
ret = VM_FAULT_LOCKED;
goto out;
}
/* Can we see a streaming write here? */
if (WARN_ON(!folio_test_uptodate(folio))) {
ret = VM_FAULT_SIGBUS | VM_FAULT_LOCKED;
goto out;
}
if (netfs_folio_group(folio) != netfs_group) {
group = netfs_folio_group(folio);
if (group != netfs_group && group != NETFS_FOLIO_COPY_TO_CACHE) {
folio_unlock(folio);
err = filemap_fdatawait_range(inode->i_mapping,
folio_pos(folio),
@ -557,702 +573,3 @@ out:
return ret;
}
EXPORT_SYMBOL(netfs_page_mkwrite);
/*
* Kill all the pages in the given range
*/
static void netfs_kill_pages(struct address_space *mapping,
loff_t start, loff_t len)
{
struct folio *folio;
pgoff_t index = start / PAGE_SIZE;
pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
_enter("%llx-%llx", start, start + len - 1);
do {
_debug("kill %lx (to %lx)", index, last);
folio = filemap_get_folio(mapping, index);
if (IS_ERR(folio)) {
next = index + 1;
continue;
}
next = folio_next_index(folio);
trace_netfs_folio(folio, netfs_folio_trace_kill);
folio_clear_uptodate(folio);
if (folio_test_fscache(folio))
folio_end_fscache(folio);
folio_end_writeback(folio);
folio_lock(folio);
generic_error_remove_folio(mapping, folio);
folio_unlock(folio);
folio_put(folio);
} while (index = next, index <= last);
_leave("");
}
/*
* Redirty all the pages in a given range.
*/
static void netfs_redirty_pages(struct address_space *mapping,
loff_t start, loff_t len)
{
struct folio *folio;
pgoff_t index = start / PAGE_SIZE;
pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
_enter("%llx-%llx", start, start + len - 1);
do {
_debug("redirty %llx @%llx", len, start);
folio = filemap_get_folio(mapping, index);
if (IS_ERR(folio)) {
next = index + 1;
continue;
}
next = folio_next_index(folio);
trace_netfs_folio(folio, netfs_folio_trace_redirty);
filemap_dirty_folio(mapping, folio);
if (folio_test_fscache(folio))
folio_end_fscache(folio);
folio_end_writeback(folio);
folio_put(folio);
} while (index = next, index <= last);
balance_dirty_pages_ratelimited(mapping);
_leave("");
}
/*
* Completion of write to server
*/
static void netfs_pages_written_back(struct netfs_io_request *wreq)
{
struct address_space *mapping = wreq->mapping;
struct netfs_folio *finfo;
struct netfs_group *group = NULL;
struct folio *folio;
pgoff_t last;
int gcount = 0;
XA_STATE(xas, &mapping->i_pages, wreq->start / PAGE_SIZE);
_enter("%llx-%llx", wreq->start, wreq->start + wreq->len);
rcu_read_lock();
last = (wreq->start + wreq->len - 1) / PAGE_SIZE;
xas_for_each(&xas, folio, last) {
WARN(!folio_test_writeback(folio),
"bad %zx @%llx page %lx %lx\n",
wreq->len, wreq->start, folio->index, last);
if ((finfo = netfs_folio_info(folio))) {
/* Streaming writes cannot be redirtied whilst under
* writeback, so discard the streaming record.
*/
folio_detach_private(folio);
group = finfo->netfs_group;
gcount++;
trace_netfs_folio(folio, netfs_folio_trace_clear_s);
kfree(finfo);
} else if ((group = netfs_folio_group(folio))) {
/* Need to detach the group pointer if the page didn't
* get redirtied. If it has been redirtied, then it
* must be within the same group.
*/
if (folio_test_dirty(folio)) {
trace_netfs_folio(folio, netfs_folio_trace_redirtied);
goto end_wb;
}
if (folio_trylock(folio)) {
if (!folio_test_dirty(folio)) {
folio_detach_private(folio);
gcount++;
trace_netfs_folio(folio, netfs_folio_trace_clear_g);
} else {
trace_netfs_folio(folio, netfs_folio_trace_redirtied);
}
folio_unlock(folio);
goto end_wb;
}
xas_pause(&xas);
rcu_read_unlock();
folio_lock(folio);
if (!folio_test_dirty(folio)) {
folio_detach_private(folio);
gcount++;
trace_netfs_folio(folio, netfs_folio_trace_clear_g);
} else {
trace_netfs_folio(folio, netfs_folio_trace_redirtied);
}
folio_unlock(folio);
rcu_read_lock();
} else {
trace_netfs_folio(folio, netfs_folio_trace_clear);
}
end_wb:
if (folio_test_fscache(folio))
folio_end_fscache(folio);
xas_advance(&xas, folio_next_index(folio) - 1);
folio_end_writeback(folio);
}
rcu_read_unlock();
netfs_put_group_many(group, gcount);
_leave("");
}
/*
* Deal with the disposition of the folios that are under writeback to close
* out the operation.
*/
static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq)
{
struct address_space *mapping = wreq->mapping;
_enter("");
switch (wreq->error) {
case 0:
netfs_pages_written_back(wreq);
break;
default:
pr_notice("R=%08x Unexpected error %d\n", wreq->debug_id, wreq->error);
fallthrough;
case -EACCES:
case -EPERM:
case -ENOKEY:
case -EKEYEXPIRED:
case -EKEYREJECTED:
case -EKEYREVOKED:
case -ENETRESET:
case -EDQUOT:
case -ENOSPC:
netfs_redirty_pages(mapping, wreq->start, wreq->len);
break;
case -EROFS:
case -EIO:
case -EREMOTEIO:
case -EFBIG:
case -ENOENT:
case -ENOMEDIUM:
case -ENXIO:
netfs_kill_pages(mapping, wreq->start, wreq->len);
break;
}
if (wreq->error)
mapping_set_error(mapping, wreq->error);
if (wreq->netfs_ops->done)
wreq->netfs_ops->done(wreq);
}
/*
* Extend the region to be written back to include subsequent contiguously
* dirty pages if possible, but don't sleep while doing so.
*
* If this page holds new content, then we can include filler zeros in the
* writeback.
*/
static void netfs_extend_writeback(struct address_space *mapping,
struct netfs_group *group,
struct xa_state *xas,
long *_count,
loff_t start,
loff_t max_len,
bool caching,
size_t *_len,
size_t *_top)
{
struct netfs_folio *finfo;
struct folio_batch fbatch;
struct folio *folio;
unsigned int i;
pgoff_t index = (start + *_len) / PAGE_SIZE;
size_t len;
void *priv;
bool stop = true;
folio_batch_init(&fbatch);
do {
/* Firstly, we gather up a batch of contiguous dirty pages
* under the RCU read lock - but we can't clear the dirty flags
* there if any of those pages are mapped.
*/
rcu_read_lock();
xas_for_each(xas, folio, ULONG_MAX) {
stop = true;
if (xas_retry(xas, folio))
continue;
if (xa_is_value(folio))
break;
if (folio->index != index) {
xas_reset(xas);
break;
}
if (!folio_try_get_rcu(folio)) {
xas_reset(xas);
continue;
}
/* Has the folio moved or been split? */
if (unlikely(folio != xas_reload(xas))) {
folio_put(folio);
xas_reset(xas);
break;
}
if (!folio_trylock(folio)) {
folio_put(folio);
xas_reset(xas);
break;
}
if (!folio_test_dirty(folio) ||
folio_test_writeback(folio) ||
folio_test_fscache(folio)) {
folio_unlock(folio);
folio_put(folio);
xas_reset(xas);
break;
}
stop = false;
len = folio_size(folio);
priv = folio_get_private(folio);
if ((const struct netfs_group *)priv != group) {
stop = true;
finfo = netfs_folio_info(folio);
if (finfo->netfs_group != group ||
finfo->dirty_offset > 0) {
folio_unlock(folio);
folio_put(folio);
xas_reset(xas);
break;
}
len = finfo->dirty_len;
}
*_top += folio_size(folio);
index += folio_nr_pages(folio);
*_count -= folio_nr_pages(folio);
*_len += len;
if (*_len >= max_len || *_count <= 0)
stop = true;
if (!folio_batch_add(&fbatch, folio))
break;
if (stop)
break;
}
xas_pause(xas);
rcu_read_unlock();
/* Now, if we obtained any folios, we can shift them to being
* writable and mark them for caching.
*/
if (!folio_batch_count(&fbatch))
break;
for (i = 0; i < folio_batch_count(&fbatch); i++) {
folio = fbatch.folios[i];
trace_netfs_folio(folio, netfs_folio_trace_store_plus);
if (!folio_clear_dirty_for_io(folio))
BUG();
folio_start_writeback(folio);
netfs_folio_start_fscache(caching, folio);
folio_unlock(folio);
}
folio_batch_release(&fbatch);
cond_resched();
} while (!stop);
}
/*
* Synchronously write back the locked page and any subsequent non-locked dirty
* pages.
*/
static ssize_t netfs_write_back_from_locked_folio(struct address_space *mapping,
struct writeback_control *wbc,
struct netfs_group *group,
struct xa_state *xas,
struct folio *folio,
unsigned long long start,
unsigned long long end)
{
struct netfs_io_request *wreq;
struct netfs_folio *finfo;
struct netfs_inode *ctx = netfs_inode(mapping->host);
unsigned long long i_size = i_size_read(&ctx->inode);
size_t len, max_len;
bool caching = netfs_is_cache_enabled(ctx);
long count = wbc->nr_to_write;
int ret;
_enter(",%lx,%llx-%llx,%u", folio->index, start, end, caching);
wreq = netfs_alloc_request(mapping, NULL, start, folio_size(folio),
NETFS_WRITEBACK);
if (IS_ERR(wreq)) {
folio_unlock(folio);
return PTR_ERR(wreq);
}
if (!folio_clear_dirty_for_io(folio))
BUG();
folio_start_writeback(folio);
netfs_folio_start_fscache(caching, folio);
count -= folio_nr_pages(folio);
/* Find all consecutive lockable dirty pages that have contiguous
* written regions, stopping when we find a page that is not
* immediately lockable, is not dirty or is missing, or we reach the
* end of the range.
*/
trace_netfs_folio(folio, netfs_folio_trace_store);
len = wreq->len;
finfo = netfs_folio_info(folio);
if (finfo) {
start += finfo->dirty_offset;
if (finfo->dirty_offset + finfo->dirty_len != len) {
len = finfo->dirty_len;
goto cant_expand;
}
len = finfo->dirty_len;
}
if (start < i_size) {
/* Trim the write to the EOF; the extra data is ignored. Also
* put an upper limit on the size of a single storedata op.
*/
max_len = 65536 * 4096;
max_len = min_t(unsigned long long, max_len, end - start + 1);
max_len = min_t(unsigned long long, max_len, i_size - start);
if (len < max_len)
netfs_extend_writeback(mapping, group, xas, &count, start,
max_len, caching, &len, &wreq->upper_len);
}
cant_expand:
len = min_t(unsigned long long, len, i_size - start);
/* We now have a contiguous set of dirty pages, each with writeback
* set; the first page is still locked at this point, but all the rest
* have been unlocked.
*/
folio_unlock(folio);
wreq->start = start;
wreq->len = len;
if (start < i_size) {
_debug("write back %zx @%llx [%llx]", len, start, i_size);
/* Speculatively write to the cache. We have to fix this up
* later if the store fails.
*/
wreq->cleanup = netfs_cleanup_buffered_write;
iov_iter_xarray(&wreq->iter, ITER_SOURCE, &mapping->i_pages, start,
wreq->upper_len);
__set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
ret = netfs_begin_write(wreq, true, netfs_write_trace_writeback);
if (ret == 0 || ret == -EIOCBQUEUED)
wbc->nr_to_write -= len / PAGE_SIZE;
} else {
_debug("write discard %zx @%llx [%llx]", len, start, i_size);
/* The dirty region was entirely beyond the EOF. */
fscache_clear_page_bits(mapping, start, len, caching);
netfs_pages_written_back(wreq);
ret = 0;
}
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
_leave(" = 1");
return 1;
}
/*
* Write a region of pages back to the server
*/
static ssize_t netfs_writepages_begin(struct address_space *mapping,
struct writeback_control *wbc,
struct netfs_group *group,
struct xa_state *xas,
unsigned long long *_start,
unsigned long long end)
{
const struct netfs_folio *finfo;
struct folio *folio;
unsigned long long start = *_start;
ssize_t ret;
void *priv;
int skips = 0;
_enter("%llx,%llx,", start, end);
search_again:
/* Find the first dirty page in the group. */
rcu_read_lock();
for (;;) {
folio = xas_find_marked(xas, end / PAGE_SIZE, PAGECACHE_TAG_DIRTY);
if (xas_retry(xas, folio) || xa_is_value(folio))
continue;
if (!folio)
break;
if (!folio_try_get_rcu(folio)) {
xas_reset(xas);
continue;
}
if (unlikely(folio != xas_reload(xas))) {
folio_put(folio);
xas_reset(xas);
continue;
}
/* Skip any dirty folio that's not in the group of interest. */
priv = folio_get_private(folio);
if ((const struct netfs_group *)priv != group) {
finfo = netfs_folio_info(folio);
if (finfo->netfs_group != group) {
folio_put(folio);
continue;
}
}
xas_pause(xas);
break;
}
rcu_read_unlock();
if (!folio)
return 0;
start = folio_pos(folio); /* May regress with THPs */
_debug("wback %lx", folio->index);
/* At this point we hold neither the i_pages lock nor the page lock:
* the page may be truncated or invalidated (changing page->mapping to
* NULL), or even swizzled back from swapper_space to tmpfs file
* mapping
*/
lock_again:
if (wbc->sync_mode != WB_SYNC_NONE) {
ret = folio_lock_killable(folio);
if (ret < 0)
return ret;
} else {
if (!folio_trylock(folio))
goto search_again;
}
if (folio->mapping != mapping ||
!folio_test_dirty(folio)) {
start += folio_size(folio);
folio_unlock(folio);
goto search_again;
}
if (folio_test_writeback(folio) ||
folio_test_fscache(folio)) {
folio_unlock(folio);
if (wbc->sync_mode != WB_SYNC_NONE) {
folio_wait_writeback(folio);
#ifdef CONFIG_FSCACHE
folio_wait_fscache(folio);
#endif
goto lock_again;
}
start += folio_size(folio);
if (wbc->sync_mode == WB_SYNC_NONE) {
if (skips >= 5 || need_resched()) {
ret = 0;
goto out;
}
skips++;
}
goto search_again;
}
ret = netfs_write_back_from_locked_folio(mapping, wbc, group, xas,
folio, start, end);
out:
if (ret > 0)
*_start = start + ret;
_leave(" = %zd [%llx]", ret, *_start);
return ret;
}
/*
* Write a region of pages back to the server
*/
static int netfs_writepages_region(struct address_space *mapping,
struct writeback_control *wbc,
struct netfs_group *group,
unsigned long long *_start,
unsigned long long end)
{
ssize_t ret;
XA_STATE(xas, &mapping->i_pages, *_start / PAGE_SIZE);
do {
ret = netfs_writepages_begin(mapping, wbc, group, &xas,
_start, end);
if (ret > 0 && wbc->nr_to_write > 0)
cond_resched();
} while (ret > 0 && wbc->nr_to_write > 0);
return ret > 0 ? 0 : ret;
}
/*
* write some of the pending data back to the server
*/
int netfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct netfs_group *group = NULL;
loff_t start, end;
int ret;
_enter("");
/* We have to be careful as we can end up racing with setattr()
* truncating the pagecache since the caller doesn't take a lock here
* to prevent it.
*/
if (wbc->range_cyclic && mapping->writeback_index) {
start = mapping->writeback_index * PAGE_SIZE;
ret = netfs_writepages_region(mapping, wbc, group,
&start, LLONG_MAX);
if (ret < 0)
goto out;
if (wbc->nr_to_write <= 0) {
mapping->writeback_index = start / PAGE_SIZE;
goto out;
}
start = 0;
end = mapping->writeback_index * PAGE_SIZE;
mapping->writeback_index = 0;
ret = netfs_writepages_region(mapping, wbc, group, &start, end);
if (ret == 0)
mapping->writeback_index = start / PAGE_SIZE;
} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
start = 0;
ret = netfs_writepages_region(mapping, wbc, group,
&start, LLONG_MAX);
if (wbc->nr_to_write > 0 && ret == 0)
mapping->writeback_index = start / PAGE_SIZE;
} else {
start = wbc->range_start;
ret = netfs_writepages_region(mapping, wbc, group,
&start, wbc->range_end);
}
out:
_leave(" = %d", ret);
return ret;
}
EXPORT_SYMBOL(netfs_writepages);
/*
* Deal with the disposition of a laundered folio.
*/
static void netfs_cleanup_launder_folio(struct netfs_io_request *wreq)
{
if (wreq->error) {
pr_notice("R=%08x Laundering error %d\n", wreq->debug_id, wreq->error);
mapping_set_error(wreq->mapping, wreq->error);
}
}
/**
* netfs_launder_folio - Clean up a dirty folio that's being invalidated
* @folio: The folio to clean
*
* This is called to write back a folio that's being invalidated when an inode
* is getting torn down. Ideally, writepages would be used instead.
*/
int netfs_launder_folio(struct folio *folio)
{
struct netfs_io_request *wreq;
struct address_space *mapping = folio->mapping;
struct netfs_folio *finfo = netfs_folio_info(folio);
struct netfs_group *group = netfs_folio_group(folio);
struct bio_vec bvec;
unsigned long long i_size = i_size_read(mapping->host);
unsigned long long start = folio_pos(folio);
size_t offset = 0, len;
int ret = 0;
if (finfo) {
offset = finfo->dirty_offset;
start += offset;
len = finfo->dirty_len;
} else {
len = folio_size(folio);
}
len = min_t(unsigned long long, len, i_size - start);
wreq = netfs_alloc_request(mapping, NULL, start, len, NETFS_LAUNDER_WRITE);
if (IS_ERR(wreq)) {
ret = PTR_ERR(wreq);
goto out;
}
if (!folio_clear_dirty_for_io(folio))
goto out_put;
trace_netfs_folio(folio, netfs_folio_trace_launder);
_debug("launder %llx-%llx", start, start + len - 1);
/* Speculatively write to the cache. We have to fix this up later if
* the store fails.
*/
wreq->cleanup = netfs_cleanup_launder_folio;
bvec_set_folio(&bvec, folio, len, offset);
iov_iter_bvec(&wreq->iter, ITER_SOURCE, &bvec, 1, len);
__set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
ret = netfs_begin_write(wreq, true, netfs_write_trace_launder);
out_put:
folio_detach_private(folio);
netfs_put_group(group);
kfree(finfo);
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
out:
folio_wait_fscache(folio);
_leave(" = %d", ret);
return ret;
}
EXPORT_SYMBOL(netfs_launder_folio);

56
fs/netfs/direct_write.c
View File

@ -34,6 +34,7 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
unsigned long long start = iocb->ki_pos;
unsigned long long end = start + iov_iter_count(iter);
ssize_t ret, n;
size_t len = iov_iter_count(iter);
bool async = !is_sync_kiocb(iocb);
_enter("");
@ -46,13 +47,17 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
_debug("uw %llx-%llx", start, end);
wreq = netfs_alloc_request(iocb->ki_filp->f_mapping, iocb->ki_filp,
start, end - start,
iocb->ki_flags & IOCB_DIRECT ?
NETFS_DIO_WRITE : NETFS_UNBUFFERED_WRITE);
wreq = netfs_create_write_req(iocb->ki_filp->f_mapping, iocb->ki_filp, start,
iocb->ki_flags & IOCB_DIRECT ?
NETFS_DIO_WRITE : NETFS_UNBUFFERED_WRITE);
if (IS_ERR(wreq))
return PTR_ERR(wreq);
wreq->io_streams[0].avail = true;
trace_netfs_write(wreq, (iocb->ki_flags & IOCB_DIRECT ?
netfs_write_trace_dio_write :
netfs_write_trace_unbuffered_write));
{
/* If this is an async op and we're not using a bounce buffer,
* we have to save the source buffer as the iterator is only
@ -63,7 +68,7 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
* request.
*/
if (async || user_backed_iter(iter)) {
n = netfs_extract_user_iter(iter, wreq->len, &wreq->iter, 0);
n = netfs_extract_user_iter(iter, len, &wreq->iter, 0);
if (n < 0) {
ret = n;
goto out;
@ -71,7 +76,6 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
wreq->direct_bv = (struct bio_vec *)wreq->iter.bvec;
wreq->direct_bv_count = n;
wreq->direct_bv_unpin = iov_iter_extract_will_pin(iter);
wreq->len = iov_iter_count(&wreq->iter);
} else {
wreq->iter = *iter;
}
@ -79,6 +83,8 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
wreq->io_iter = wreq->iter;
}
__set_bit(NETFS_RREQ_USE_IO_ITER, &wreq->flags);
/* Copy the data into the bounce buffer and encrypt it. */
// TODO
@ -87,10 +93,7 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
if (async)
wreq->iocb = iocb;
wreq->cleanup = netfs_cleanup_dio_write;
ret = netfs_begin_write(wreq, is_sync_kiocb(iocb),
iocb->ki_flags & IOCB_DIRECT ?
netfs_write_trace_dio_write :
netfs_write_trace_unbuffered_write);
ret = netfs_unbuffered_write(wreq, is_sync_kiocb(iocb), iov_iter_count(&wreq->io_iter));
if (ret < 0) {
_debug("begin = %zd", ret);
goto out;
@ -100,9 +103,8 @@ static ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov
trace_netfs_rreq(wreq, netfs_rreq_trace_wait_ip);
wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
TASK_UNINTERRUPTIBLE);
smp_rmb(); /* Read error/transferred after RIP flag */
ret = wreq->error;
_debug("waited = %zd", ret);
if (ret == 0) {
ret = wreq->transferred;
iocb->ki_pos += ret;
@ -132,18 +134,20 @@ out:
ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
struct netfs_inode *ictx = netfs_inode(inode);
unsigned long long end;
ssize_t ret;
loff_t pos = iocb->ki_pos;
unsigned long long end = pos + iov_iter_count(from) - 1;
_enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode));
_enter("%llx,%zx,%llx", pos, iov_iter_count(from), i_size_read(inode));
if (!iov_iter_count(from))
return 0;
trace_netfs_write_iter(iocb, from);
netfs_stat(&netfs_n_rh_dio_write);
netfs_stat(&netfs_n_wh_dio_write);
ret = netfs_start_io_direct(inode);
if (ret < 0)
@ -157,7 +161,25 @@ ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from)
ret = file_update_time(file);
if (ret < 0)
goto out;
ret = kiocb_invalidate_pages(iocb, iov_iter_count(from));
if (iocb->ki_flags & IOCB_NOWAIT) {
/* We could block if there are any pages in the range. */
ret = -EAGAIN;
if (filemap_range_has_page(mapping, pos, end))
if (filemap_invalidate_inode(inode, true, pos, end))
goto out;
} else {
ret = filemap_write_and_wait_range(mapping, pos, end);
if (ret < 0)
goto out;
}
/*
* After a write we want buffered reads to be sure to go to disk to get
* the new data. We invalidate clean cached page from the region we're
* about to write. We do this *before* the write so that we can return
* without clobbering -EIOCBQUEUED from ->direct_IO().
*/
ret = filemap_invalidate_inode(inode, true, pos, end);
if (ret < 0)
goto out;
end = iocb->ki_pos + iov_iter_count(from);

14
fs/netfs/fscache_io.c
View File

@ -166,6 +166,7 @@ struct fscache_write_request {
loff_t start;
size_t len;
bool set_bits;
bool using_pgpriv2;
netfs_io_terminated_t term_func;
void *term_func_priv;
};
@ -182,7 +183,7 @@ void __fscache_clear_page_bits(struct address_space *mapping,
rcu_read_lock();
xas_for_each(&xas, page, last) {
end_page_fscache(page);
folio_end_private_2(page_folio(page));
}
rcu_read_unlock();
}
@ -197,8 +198,9 @@ static void fscache_wreq_done(void *priv, ssize_t transferred_or_error,
{
struct fscache_write_request *wreq = priv;
fscache_clear_page_bits(wreq->mapping, wreq->start, wreq->len,
wreq->set_bits);
if (wreq->using_pgpriv2)
fscache_clear_page_bits(wreq->mapping, wreq->start, wreq->len,
wreq->set_bits);
if (wreq->term_func)
wreq->term_func(wreq->term_func_priv, transferred_or_error,
@ -212,7 +214,7 @@ void __fscache_write_to_cache(struct fscache_cookie *cookie,
loff_t start, size_t len, loff_t i_size,
netfs_io_terminated_t term_func,
void *term_func_priv,
bool cond)
bool using_pgpriv2, bool cond)
{
struct fscache_write_request *wreq;
struct netfs_cache_resources *cres;
@ -230,6 +232,7 @@ void __fscache_write_to_cache(struct fscache_cookie *cookie,
wreq->mapping = mapping;
wreq->start = start;
wreq->len = len;
wreq->using_pgpriv2 = using_pgpriv2;
wreq->set_bits = cond;
wreq->term_func = term_func;
wreq->term_func_priv = term_func_priv;
@ -257,7 +260,8 @@ abandon_end:
abandon_free:
kfree(wreq);
abandon:
fscache_clear_page_bits(mapping, start, len, cond);
if (using_pgpriv2)
fscache_clear_page_bits(mapping, start, len, cond);
if (term_func)
term_func(term_func_priv, ret, false);
}

55
fs/netfs/internal.h
View File

@ -37,6 +37,8 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync);
extern unsigned int netfs_debug;
extern struct list_head netfs_io_requests;
extern spinlock_t netfs_proc_lock;
extern mempool_t netfs_request_pool;
extern mempool_t netfs_subrequest_pool;
#ifdef CONFIG_PROC_FS
static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq)
@ -90,23 +92,13 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
}
/*
* output.c
*/
int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
enum netfs_write_trace what);
struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end);
int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb);
/*
* stats.c
*/
#ifdef CONFIG_NETFS_STATS
extern atomic_t netfs_n_rh_dio_read;
extern atomic_t netfs_n_rh_dio_write;
extern atomic_t netfs_n_rh_readahead;
extern atomic_t netfs_n_rh_readpage;
extern atomic_t netfs_n_rh_read_folio;
extern atomic_t netfs_n_rh_rreq;
extern atomic_t netfs_n_rh_sreq;
extern atomic_t netfs_n_rh_download;
@ -123,6 +115,10 @@ extern atomic_t netfs_n_rh_write_begin;
extern atomic_t netfs_n_rh_write_done;
extern atomic_t netfs_n_rh_write_failed;
extern atomic_t netfs_n_rh_write_zskip;
extern atomic_t netfs_n_wh_buffered_write;
extern atomic_t netfs_n_wh_writethrough;
extern atomic_t netfs_n_wh_dio_write;
extern atomic_t netfs_n_wh_writepages;
extern atomic_t netfs_n_wh_wstream_conflict;
extern atomic_t netfs_n_wh_upload;
extern atomic_t netfs_n_wh_upload_done;
@ -148,6 +144,33 @@ static inline void netfs_stat_d(atomic_t *stat)
#define netfs_stat_d(x) do {} while(0)
#endif
/*
* write_collect.c
*/
int netfs_folio_written_back(struct folio *folio);
void netfs_write_collection_worker(struct work_struct *work);
void netfs_wake_write_collector(struct netfs_io_request *wreq, bool was_async);
/*
* write_issue.c
*/
struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
struct file *file,
loff_t start,
enum netfs_io_origin origin);
void netfs_reissue_write(struct netfs_io_stream *stream,
struct netfs_io_subrequest *subreq);
int netfs_advance_write(struct netfs_io_request *wreq,
struct netfs_io_stream *stream,
loff_t start, size_t len, bool to_eof);
struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
struct folio *folio, size_t copied, bool to_page_end,
struct folio **writethrough_cache);
int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
struct folio *writethrough_cache);
int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t len);
/*
* Miscellaneous functions.
*/
@ -168,7 +191,7 @@ static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
*/
static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_group)
{
if (netfs_group)
if (netfs_group && netfs_group != NETFS_FOLIO_COPY_TO_CACHE)
refcount_inc(&netfs_group->ref);
return netfs_group;
}
@ -178,7 +201,9 @@ static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_grou
*/
static inline void netfs_put_group(struct netfs_group *netfs_group)
{
if (netfs_group && refcount_dec_and_test(&netfs_group->ref))
if (netfs_group &&
netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
refcount_dec_and_test(&netfs_group->ref))
netfs_group->free(netfs_group);
}
@ -187,7 +212,9 @@ static inline void netfs_put_group(struct netfs_group *netfs_group)
*/
static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr)
{
if (netfs_group && refcount_sub_and_test(nr, &netfs_group->ref))
if (netfs_group &&
netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
refcount_sub_and_test(nr, &netfs_group->ref))
netfs_group->free(netfs_group);
}

155
fs/netfs/io.c
View File

@ -98,145 +98,6 @@ static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
netfs_put_request(rreq, was_async, netfs_rreq_trace_put_complete);
}
/*
* Deal with the completion of writing the data to the cache. We have to clear
* the PG_fscache bits on the folios involved and release the caller's ref.
*
* May be called in softirq mode and we inherit a ref from the caller.
*/
static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
bool was_async)
{
struct netfs_io_subrequest *subreq;
struct folio *folio;
pgoff_t unlocked = 0;
bool have_unlocked = false;
rcu_read_lock();
list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
XA_STATE(xas, &rreq->mapping->i_pages, subreq->start / PAGE_SIZE);
xas_for_each(&xas, folio, (subreq->start + subreq->len - 1) / PAGE_SIZE) {
if (xas_retry(&xas, folio))
continue;
/* We might have multiple writes from the same huge
* folio, but we mustn't unlock a folio more than once.
*/
if (have_unlocked && folio->index <= unlocked)
continue;
unlocked = folio_next_index(folio) - 1;
trace_netfs_folio(folio, netfs_folio_trace_end_copy);
folio_end_fscache(folio);
have_unlocked = true;
}
}
rcu_read_unlock();
netfs_rreq_completed(rreq, was_async);
}
static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
bool was_async)
{
struct netfs_io_subrequest *subreq = priv;
struct netfs_io_request *rreq = subreq->rreq;
if (IS_ERR_VALUE(transferred_or_error)) {
netfs_stat(&netfs_n_rh_write_failed);
trace_netfs_failure(rreq, subreq, transferred_or_error,
netfs_fail_copy_to_cache);
} else {
netfs_stat(&netfs_n_rh_write_done);
}
trace_netfs_sreq(subreq, netfs_sreq_trace_write_term);
/* If we decrement nr_copy_ops to 0, the ref belongs to us. */
if (atomic_dec_and_test(&rreq->nr_copy_ops))
netfs_rreq_unmark_after_write(rreq, was_async);
netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
}
/*
* Perform any outstanding writes to the cache. We inherit a ref from the
* caller.
*/
static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
{
struct netfs_cache_resources *cres = &rreq->cache_resources;
struct netfs_io_subrequest *subreq, *next, *p;
struct iov_iter iter;
int ret;
trace_netfs_rreq(rreq, netfs_rreq_trace_copy);
/* We don't want terminating writes trying to wake us up whilst we're
* still going through the list.
*/
atomic_inc(&rreq->nr_copy_ops);
list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
list_del_init(&subreq->rreq_link);
netfs_put_subrequest(subreq, false,
netfs_sreq_trace_put_no_copy);
}
}
list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
/* Amalgamate adjacent writes */
while (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {
next = list_next_entry(subreq, rreq_link);
if (next->start != subreq->start + subreq->len)
break;
subreq->len += next->len;
list_del_init(&next->rreq_link);
netfs_put_subrequest(next, false,
netfs_sreq_trace_put_merged);
}
ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len,
subreq->len, rreq->i_size, true);
if (ret < 0) {
trace_netfs_failure(rreq, subreq, ret, netfs_fail_prepare_write);
trace_netfs_sreq(subreq, netfs_sreq_trace_write_skip);
continue;
}
iov_iter_xarray(&iter, ITER_SOURCE, &rreq->mapping->i_pages,
subreq->start, subreq->len);
atomic_inc(&rreq->nr_copy_ops);
netfs_stat(&netfs_n_rh_write);
netfs_get_subrequest(subreq, netfs_sreq_trace_get_copy_to_cache);
trace_netfs_sreq(subreq, netfs_sreq_trace_write);
cres->ops->write(cres, subreq->start, &iter,
netfs_rreq_copy_terminated, subreq);
}
/* If we decrement nr_copy_ops to 0, the usage ref belongs to us. */
if (atomic_dec_and_test(&rreq->nr_copy_ops))
netfs_rreq_unmark_after_write(rreq, false);
}
static void netfs_rreq_write_to_cache_work(struct work_struct *work)
{
struct netfs_io_request *rreq =
container_of(work, struct netfs_io_request, work);
netfs_rreq_do_write_to_cache(rreq);
}
static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq)
{
rreq->work.func = netfs_rreq_write_to_cache_work;
if (!queue_work(system_unbound_wq, &rreq->work))
BUG();
}
/*
* Handle a short read.
*/
@ -409,9 +270,6 @@ again:
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
if (test_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags))
return netfs_rreq_write_to_cache(rreq);
netfs_rreq_completed(rreq, was_async);
}
@ -618,7 +476,7 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
set:
if (subreq->len > rreq->len)
pr_warn("R=%08x[%u] SREQ>RREQ %zx > %zx\n",
pr_warn("R=%08x[%u] SREQ>RREQ %zx > %llx\n",
rreq->debug_id, subreq->debug_index,
subreq->len, rreq->len);
@ -643,8 +501,7 @@ out:
* Slice off a piece of a read request and submit an I/O request for it.
*/
static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
struct iov_iter *io_iter,
unsigned int *_debug_index)
struct iov_iter *io_iter)
{
struct netfs_io_subrequest *subreq;
enum netfs_io_source source;
@ -653,11 +510,10 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
if (!subreq)
return false;
subreq->debug_index = (*_debug_index)++;
subreq->start = rreq->start + rreq->submitted;
subreq->len = io_iter->count;
_debug("slice %llx,%zx,%zx", subreq->start, subreq->len, rreq->submitted);
_debug("slice %llx,%zx,%llx", subreq->start, subreq->len, rreq->submitted);
list_add_tail(&subreq->rreq_link, &rreq->subrequests);
/* Call out to the cache to find out what it can do with the remaining
@ -707,7 +563,6 @@ subreq_failed:
int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
{
struct iov_iter io_iter;
unsigned int debug_index = 0;
int ret;
_enter("R=%x %llx-%llx",
@ -733,12 +588,12 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
atomic_set(&rreq->nr_outstanding, 1);
io_iter = rreq->io_iter;
do {
_debug("submit %llx + %zx >= %llx",
_debug("submit %llx + %llx >= %llx",
rreq->start, rreq->submitted, rreq->i_size);
if (rreq->origin == NETFS_DIO_READ &&
rreq->start + rreq->submitted >= rreq->i_size)
break;
if (!netfs_rreq_submit_slice(rreq, &io_iter, &debug_index))
if (!netfs_rreq_submit_slice(rreq, &io_iter))
break;
if (test_bit(NETFS_RREQ_BLOCKED, &rreq->flags) &&
test_bit(NETFS_RREQ_NONBLOCK, &rreq->flags))

55
fs/netfs/main.c
View File

@ -7,6 +7,7 @@
#include <linux/module.h>
#include <linux/export.h>
#include <linux/mempool.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"
@ -23,6 +24,11 @@ unsigned netfs_debug;
module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
static struct kmem_cache *netfs_request_slab;
static struct kmem_cache *netfs_subrequest_slab;
mempool_t netfs_request_pool;
mempool_t netfs_subrequest_pool;
#ifdef CONFIG_PROC_FS
LIST_HEAD(netfs_io_requests);
DEFINE_SPINLOCK(netfs_proc_lock);
@ -31,9 +37,9 @@ static const char *netfs_origins[nr__netfs_io_origin] = {
[NETFS_READAHEAD] = "RA",
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
[NETFS_COPY_TO_CACHE] = "CC",
[NETFS_WRITEBACK] = "WB",
[NETFS_WRITETHROUGH] = "WT",
[NETFS_LAUNDER_WRITE] = "LW",
[NETFS_UNBUFFERED_WRITE] = "UW",
[NETFS_DIO_READ] = "DR",
[NETFS_DIO_WRITE] = "DW",
@ -56,7 +62,7 @@ static int netfs_requests_seq_show(struct seq_file *m, void *v)
rreq = list_entry(v, struct netfs_io_request, proc_link);
seq_printf(m,
"%08x %s %3d %2lx %4d %3d @%04llx %zx/%zx",
"%08x %s %3d %2lx %4d %3d @%04llx %llx/%llx",
rreq->debug_id,
netfs_origins[rreq->origin],
refcount_read(&rreq->ref),
@ -98,25 +104,54 @@ static int __init netfs_init(void)
{
int ret = -ENOMEM;
netfs_request_slab = kmem_cache_create("netfs_request",
sizeof(struct netfs_io_request), 0,
SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
NULL);
if (!netfs_request_slab)
goto error_req;
if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0)
goto error_reqpool;
netfs_subrequest_slab = kmem_cache_create("netfs_subrequest",
sizeof(struct netfs_io_subrequest), 0,
SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
NULL);
if (!netfs_subrequest_slab)
goto error_subreq;
if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0)
goto error_subreqpool;
if (!proc_mkdir("fs/netfs", NULL))
goto error;
goto error_proc;
if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL,
&netfs_requests_seq_ops))
goto error_proc;
goto error_procfile;
#ifdef CONFIG_FSCACHE_STATS
if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL,
netfs_stats_show))
goto error_proc;
goto error_procfile;
#endif
ret = fscache_init();
if (ret < 0)
goto error_proc;
goto error_fscache;
return 0;
error_proc:
error_fscache:
error_procfile:
remove_proc_entry("fs/netfs", NULL);
error:
error_proc:
mempool_exit(&netfs_subrequest_pool);
error_subreqpool:
kmem_cache_destroy(netfs_subrequest_slab);
error_subreq:
mempool_exit(&netfs_request_pool);
error_reqpool:
kmem_cache_destroy(netfs_request_slab);
error_req:
return ret;
}
fs_initcall(netfs_init);
@ -125,5 +160,9 @@ static void __exit netfs_exit(void)
{
fscache_exit();
remove_proc_entry("fs/netfs", NULL);
mempool_exit(&netfs_subrequest_pool);
kmem_cache_destroy(netfs_subrequest_slab);
mempool_exit(&netfs_request_pool);
kmem_cache_destroy(netfs_request_slab);
}
module_exit(netfs_exit);

10
fs/netfs/misc.c
View File

@ -177,13 +177,11 @@ EXPORT_SYMBOL(netfs_clear_inode_writeback);
*/
void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
{
struct netfs_folio *finfo = NULL;
struct netfs_folio *finfo;
size_t flen = folio_size(folio);
_enter("{%lx},%zx,%zx", folio->index, offset, length);
folio_wait_fscache(folio);
if (!folio_test_private(folio))
return;
@ -248,12 +246,6 @@ bool netfs_release_folio(struct folio *folio, gfp_t gfp)
if (folio_test_private(folio))
return false;
if (folio_test_fscache(folio)) {
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
folio_wait_fscache(folio);
}
fscache_note_page_release(netfs_i_cookie(ctx));
return true;
}

79
fs/netfs/objects.c
View File

@ -6,6 +6,8 @@
*/
#include <linux/slab.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include "internal.h"
/*
@ -20,17 +22,22 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
struct inode *inode = file ? file_inode(file) : mapping->host;
struct netfs_inode *ctx = netfs_inode(inode);
struct netfs_io_request *rreq;
mempool_t *mempool = ctx->ops->request_pool ?: &netfs_request_pool;
struct kmem_cache *cache = mempool->pool_data;
bool is_unbuffered = (origin == NETFS_UNBUFFERED_WRITE ||
origin == NETFS_DIO_READ ||
origin == NETFS_DIO_WRITE);
bool cached = !is_unbuffered && netfs_is_cache_enabled(ctx);
int ret;
rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request),
GFP_KERNEL);
if (!rreq)
return ERR_PTR(-ENOMEM);
for (;;) {
rreq = mempool_alloc(mempool, GFP_KERNEL);
if (rreq)
break;
msleep(10);
}
memset(rreq, 0, kmem_cache_size(cache));
rreq->start = start;
rreq->len = len;
rreq->upper_len = len;
@ -40,19 +47,27 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
rreq->inode = inode;
rreq->i_size = i_size_read(inode);
rreq->debug_id = atomic_inc_return(&debug_ids);
rreq->wsize = INT_MAX;
spin_lock_init(&rreq->lock);
INIT_LIST_HEAD(&rreq->io_streams[0].subrequests);
INIT_LIST_HEAD(&rreq->io_streams[1].subrequests);
INIT_LIST_HEAD(&rreq->subrequests);
INIT_WORK(&rreq->work, NULL);
refcount_set(&rreq->ref, 1);
__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
if (cached)
if (cached) {
__set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags);
if (test_bit(NETFS_ICTX_USE_PGPRIV2, &ctx->flags))
/* Filesystem uses deprecated PG_private_2 marking. */
__set_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags);
}
if (file && file->f_flags & O_NONBLOCK)
__set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags);
if (rreq->netfs_ops->init_request) {
ret = rreq->netfs_ops->init_request(rreq, file);
if (ret < 0) {
kfree(rreq);
mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool);
return ERR_PTR(ret);
}
}
@ -74,6 +89,8 @@ void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace
void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
{
struct netfs_io_subrequest *subreq;
struct netfs_io_stream *stream;
int s;
while (!list_empty(&rreq->subrequests)) {
subreq = list_first_entry(&rreq->subrequests,
@ -82,6 +99,25 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
netfs_put_subrequest(subreq, was_async,
netfs_sreq_trace_put_clear);
}
for (s = 0; s < ARRAY_SIZE(rreq->io_streams); s++) {
stream = &rreq->io_streams[s];
while (!list_empty(&stream->subrequests)) {
subreq = list_first_entry(&stream->subrequests,
struct netfs_io_subrequest, rreq_link);
list_del(&subreq->rreq_link);
netfs_put_subrequest(subreq, was_async,
netfs_sreq_trace_put_clear);
}
}
}
static void netfs_free_request_rcu(struct rcu_head *rcu)
{
struct netfs_io_request *rreq = container_of(rcu, struct netfs_io_request, rcu);
mempool_free(rreq, rreq->netfs_ops->request_pool ?: &netfs_request_pool);
netfs_stat_d(&netfs_n_rh_rreq);
}
static void netfs_free_request(struct work_struct *work)
@ -106,8 +142,7 @@ static void netfs_free_request(struct work_struct *work)
}
kvfree(rreq->direct_bv);
}
kfree_rcu(rreq, rcu);
netfs_stat_d(&netfs_n_rh_rreq);
call_rcu(&rreq->rcu, netfs_free_request_rcu);
}
void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
@ -139,19 +174,25 @@ void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq)
{
struct netfs_io_subrequest *subreq;
mempool_t *mempool = rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool;
struct kmem_cache *cache = mempool->pool_data;
subreq = kzalloc(rreq->netfs_ops->io_subrequest_size ?:
sizeof(struct netfs_io_subrequest),
GFP_KERNEL);
if (subreq) {
INIT_WORK(&subreq->work, NULL);
INIT_LIST_HEAD(&subreq->rreq_link);
refcount_set(&subreq->ref, 2);
subreq->rreq = rreq;
netfs_get_request(rreq, netfs_rreq_trace_get_subreq);
netfs_stat(&netfs_n_rh_sreq);
for (;;) {
subreq = mempool_alloc(rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool,
GFP_KERNEL);
if (subreq)
break;
msleep(10);
}
memset(subreq, 0, kmem_cache_size(cache));
INIT_WORK(&subreq->work, NULL);
INIT_LIST_HEAD(&subreq->rreq_link);
refcount_set(&subreq->ref, 2);
subreq->rreq = rreq;
subreq->debug_index = atomic_inc_return(&rreq->subreq_counter);
netfs_get_request(rreq, netfs_rreq_trace_get_subreq);
netfs_stat(&netfs_n_rh_sreq);
return subreq;
}
@ -173,7 +214,7 @@ static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
trace_netfs_sreq(subreq, netfs_sreq_trace_free);
if (rreq->netfs_ops->free_subrequest)
rreq->netfs_ops->free_subrequest(subreq);
kfree(subreq);
mempool_free(subreq, rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool);
netfs_stat_d(&netfs_n_rh_sreq);
netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq);
}

478
fs/netfs/output.c
View File

@ -1,478 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Network filesystem high-level write support.
*
* Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include "internal.h"
/**
* netfs_create_write_request - Create a write operation.
* @wreq: The write request this is storing from.
* @dest: The destination type
* @start: Start of the region this write will modify
* @len: Length of the modification
* @worker: The worker function to handle the write(s)
*
* Allocate a write operation, set it up and add it to the list on a write
* request.
*/
struct netfs_io_subrequest *netfs_create_write_request(struct netfs_io_request *wreq,
enum netfs_io_source dest,
loff_t start, size_t len,
work_func_t worker)
{
struct netfs_io_subrequest *subreq;
subreq = netfs_alloc_subrequest(wreq);
if (subreq) {
INIT_WORK(&subreq->work, worker);
subreq->source = dest;
subreq->start = start;
subreq->len = len;
subreq->debug_index = wreq->subreq_counter++;
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload);
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write);
break;
default:
BUG();
}
subreq->io_iter = wreq->io_iter;
iov_iter_advance(&subreq->io_iter, subreq->start - wreq->start);
iov_iter_truncate(&subreq->io_iter, subreq->len);
trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index,
refcount_read(&subreq->ref),
netfs_sreq_trace_new);
atomic_inc(&wreq->nr_outstanding);
list_add_tail(&subreq->rreq_link, &wreq->subrequests);
trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
}
return subreq;
}
EXPORT_SYMBOL(netfs_create_write_request);
/*
* Process a completed write request once all the component operations have
* been completed.
*/
static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async)
{
struct netfs_io_subrequest *subreq;
struct netfs_inode *ctx = netfs_inode(wreq->inode);
size_t transferred = 0;
_enter("R=%x[]", wreq->debug_id);
trace_netfs_rreq(wreq, netfs_rreq_trace_write_done);
list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
if (subreq->error || subreq->transferred == 0)
break;
transferred += subreq->transferred;
if (subreq->transferred < subreq->len)
break;
}
wreq->transferred = transferred;
list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
if (!subreq->error)
continue;
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
/* Depending on the type of failure, this may prevent
* writeback completion unless we're in disconnected
* mode.
*/
if (!wreq->error)
wreq->error = subreq->error;
break;
case NETFS_WRITE_TO_CACHE:
/* Failure doesn't prevent writeback completion unless
* we're in disconnected mode.
*/
if (subreq->error != -ENOBUFS)
ctx->ops->invalidate_cache(wreq);
break;
default:
WARN_ON_ONCE(1);
if (!wreq->error)
wreq->error = -EIO;
return;
}
}
wreq->cleanup(wreq);
if (wreq->origin == NETFS_DIO_WRITE &&
wreq->mapping->nrpages) {
pgoff_t first = wreq->start >> PAGE_SHIFT;
pgoff_t last = (wreq->start + wreq->transferred - 1) >> PAGE_SHIFT;
invalidate_inode_pages2_range(wreq->mapping, first, last);
}
if (wreq->origin == NETFS_DIO_WRITE)
inode_dio_end(wreq->inode);
_debug("finished");
trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip);
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &wreq->flags);
wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS);
if (wreq->iocb) {
wreq->iocb->ki_pos += transferred;
if (wreq->iocb->ki_complete)
wreq->iocb->ki_complete(
wreq->iocb, wreq->error ? wreq->error : transferred);
}
netfs_clear_subrequests(wreq, was_async);
netfs_put_request(wreq, was_async, netfs_rreq_trace_put_complete);
}
/*
* Deal with the completion of writing the data to the cache.
*/
void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
bool was_async)
{
struct netfs_io_subrequest *subreq = _op;
struct netfs_io_request *wreq = subreq->rreq;
unsigned int u;
_enter("%x[%x] %zd", wreq->debug_id, subreq->debug_index, transferred_or_error);
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload_done);
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write_done);
break;
case NETFS_INVALID_WRITE:
break;
default:
BUG();
}
if (IS_ERR_VALUE(transferred_or_error)) {
subreq->error = transferred_or_error;
trace_netfs_failure(wreq, subreq, transferred_or_error,
netfs_fail_write);
goto failed;
}
if (WARN(transferred_or_error > subreq->len - subreq->transferred,
"Subreq excess write: R%x[%x] %zd > %zu - %zu",
wreq->debug_id, subreq->debug_index,
transferred_or_error, subreq->len, subreq->transferred))
transferred_or_error = subreq->len - subreq->transferred;
subreq->error = 0;
subreq->transferred += transferred_or_error;
if (iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred)
pr_warn("R=%08x[%u] ITER POST-MISMATCH %zx != %zx-%zx %x\n",
wreq->debug_id, subreq->debug_index,
iov_iter_count(&subreq->io_iter), subreq->len,
subreq->transferred, subreq->io_iter.iter_type);
if (subreq->transferred < subreq->len)
goto incomplete;
__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
out:
trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
/* If we decrement nr_outstanding to 0, the ref belongs to us. */
u = atomic_dec_return(&wreq->nr_outstanding);
if (u == 0)
netfs_write_terminated(wreq, was_async);
else if (u == 1)
wake_up_var(&wreq->nr_outstanding);
netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
return;
incomplete:
if (transferred_or_error == 0) {
if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) {
subreq->error = -ENODATA;
goto failed;
}
} else {
__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
}
__set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
set_bit(NETFS_RREQ_INCOMPLETE_IO, &wreq->flags);
goto out;
failed:
switch (subreq->source) {
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write_failed);
set_bit(NETFS_RREQ_INCOMPLETE_IO, &wreq->flags);
break;
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload_failed);
set_bit(NETFS_RREQ_FAILED, &wreq->flags);
wreq->error = subreq->error;
break;
default:
break;
}
goto out;
}
EXPORT_SYMBOL(netfs_write_subrequest_terminated);
static void netfs_write_to_cache_op(struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *wreq = subreq->rreq;
struct netfs_cache_resources *cres = &wreq->cache_resources;
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
cres->ops->write(cres, subreq->start, &subreq->io_iter,
netfs_write_subrequest_terminated, subreq);
}
static void netfs_write_to_cache_op_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq =
container_of(work, struct netfs_io_subrequest, work);
netfs_write_to_cache_op(subreq);
}
/**
* netfs_queue_write_request - Queue a write request for attention
* @subreq: The write request to be queued
*
* Queue the specified write request for processing by a worker thread. We
* pass the caller's ref on the request to the worker thread.
*/
void netfs_queue_write_request(struct netfs_io_subrequest *subreq)
{
if (!queue_work(system_unbound_wq, &subreq->work))
netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_wip);
}
EXPORT_SYMBOL(netfs_queue_write_request);
/*
* Set up a op for writing to the cache.
*/
static void netfs_set_up_write_to_cache(struct netfs_io_request *wreq)
{
struct netfs_cache_resources *cres = &wreq->cache_resources;
struct netfs_io_subrequest *subreq;
struct netfs_inode *ctx = netfs_inode(wreq->inode);
struct fscache_cookie *cookie = netfs_i_cookie(ctx);
loff_t start = wreq->start;
size_t len = wreq->len;
int ret;
if (!fscache_cookie_enabled(cookie)) {
clear_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags);
return;
}
_debug("write to cache");
ret = fscache_begin_write_operation(cres, cookie);
if (ret < 0)
return;
ret = cres->ops->prepare_write(cres, &start, &len, wreq->upper_len,
i_size_read(wreq->inode), true);
if (ret < 0)
return;
subreq = netfs_create_write_request(wreq, NETFS_WRITE_TO_CACHE, start, len,
netfs_write_to_cache_op_worker);
if (!subreq)
return;
netfs_write_to_cache_op(subreq);
}
/*
* Begin the process of writing out a chunk of data.
*
* We are given a write request that holds a series of dirty regions and
* (partially) covers a sequence of folios, all of which are present. The
* pages must have been marked as writeback as appropriate.
*
* We need to perform the following steps:
*
* (1) If encrypting, create an output buffer and encrypt each block of the
* data into it, otherwise the output buffer will point to the original
* folios.
*
* (2) If the data is to be cached, set up a write op for the entire output
* buffer to the cache, if the cache wants to accept it.
*
* (3) If the data is to be uploaded (ie. not merely cached):
*
* (a) If the data is to be compressed, create a compression buffer and
* compress the data into it.
*
* (b) For each destination we want to upload to, set up write ops to write
* to that destination. We may need multiple writes if the data is not
* contiguous or the span exceeds wsize for a server.
*/
int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
enum netfs_write_trace what)
{
struct netfs_inode *ctx = netfs_inode(wreq->inode);
_enter("R=%x %llx-%llx f=%lx",
wreq->debug_id, wreq->start, wreq->start + wreq->len - 1,
wreq->flags);
trace_netfs_write(wreq, what);
if (wreq->len == 0 || wreq->iter.count == 0) {
pr_err("Zero-sized write [R=%x]\n", wreq->debug_id);
return -EIO;
}
if (wreq->origin == NETFS_DIO_WRITE)
inode_dio_begin(wreq->inode);
wreq->io_iter = wreq->iter;
/* ->outstanding > 0 carries a ref */
netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
atomic_set(&wreq->nr_outstanding, 1);
/* Start the encryption/compression going. We can do that in the
* background whilst we generate a list of write ops that we want to
* perform.
*/
// TODO: Encrypt or compress the region as appropriate
/* We need to write all of the region to the cache */
if (test_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags))
netfs_set_up_write_to_cache(wreq);
/* However, we don't necessarily write all of the region to the server.
* Caching of reads is being managed this way also.
*/
if (test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
ctx->ops->create_write_requests(wreq, wreq->start, wreq->len);
if (atomic_dec_and_test(&wreq->nr_outstanding))
netfs_write_terminated(wreq, false);
if (!may_wait)
return -EIOCBQUEUED;
wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
TASK_UNINTERRUPTIBLE);
return wreq->error;
}
/*
* Begin a write operation for writing through the pagecache.
*/
struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len)
{
struct netfs_io_request *wreq;
struct file *file = iocb->ki_filp;
wreq = netfs_alloc_request(file->f_mapping, file, iocb->ki_pos, len,
NETFS_WRITETHROUGH);
if (IS_ERR(wreq))
return wreq;
trace_netfs_write(wreq, netfs_write_trace_writethrough);
__set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
iov_iter_xarray(&wreq->iter, ITER_SOURCE, &wreq->mapping->i_pages, wreq->start, 0);
wreq->io_iter = wreq->iter;
/* ->outstanding > 0 carries a ref */
netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
atomic_set(&wreq->nr_outstanding, 1);
return wreq;
}
static void netfs_submit_writethrough(struct netfs_io_request *wreq, bool final)
{
struct netfs_inode *ictx = netfs_inode(wreq->inode);
unsigned long long start;
size_t len;
if (!test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
return;
start = wreq->start + wreq->submitted;
len = wreq->iter.count - wreq->submitted;
if (!final) {
len /= wreq->wsize; /* Round to number of maximum packets */
len *= wreq->wsize;
}
ictx->ops->create_write_requests(wreq, start, len);
wreq->submitted += len;
}
/*
* Advance the state of the write operation used when writing through the
* pagecache. Data has been copied into the pagecache that we need to append
* to the request. If we've added more than wsize then we need to create a new
* subrequest.
*/
int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end)
{
_enter("ic=%zu sb=%zu ws=%u cp=%zu tp=%u",
wreq->iter.count, wreq->submitted, wreq->wsize, copied, to_page_end);
wreq->iter.count += copied;
wreq->io_iter.count += copied;
if (to_page_end && wreq->io_iter.count - wreq->submitted >= wreq->wsize)
netfs_submit_writethrough(wreq, false);
return wreq->error;
}
/*
* End a write operation used when writing through the pagecache.
*/
int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb)
{
int ret = -EIOCBQUEUED;
_enter("ic=%zu sb=%zu ws=%u",
wreq->iter.count, wreq->submitted, wreq->wsize);
if (wreq->submitted < wreq->io_iter.count)
netfs_submit_writethrough(wreq, true);
if (atomic_dec_and_test(&wreq->nr_outstanding))
netfs_write_terminated(wreq, false);
if (is_sync_kiocb(iocb)) {
wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
TASK_UNINTERRUPTIBLE);
ret = wreq->error;
}
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
return ret;
}

17
fs/netfs/stats.c
View File

@ -10,9 +10,8 @@
#include "internal.h"
atomic_t netfs_n_rh_dio_read;
atomic_t netfs_n_rh_dio_write;
atomic_t netfs_n_rh_readahead;
atomic_t netfs_n_rh_readpage;
atomic_t netfs_n_rh_read_folio;
atomic_t netfs_n_rh_rreq;
atomic_t netfs_n_rh_sreq;
atomic_t netfs_n_rh_download;
@ -29,6 +28,10 @@ atomic_t netfs_n_rh_write_begin;
atomic_t netfs_n_rh_write_done;
atomic_t netfs_n_rh_write_failed;
atomic_t netfs_n_rh_write_zskip;
atomic_t netfs_n_wh_buffered_write;
atomic_t netfs_n_wh_writethrough;
atomic_t netfs_n_wh_dio_write;
atomic_t netfs_n_wh_writepages;
atomic_t netfs_n_wh_wstream_conflict;
atomic_t netfs_n_wh_upload;
atomic_t netfs_n_wh_upload_done;
@ -39,13 +42,17 @@ atomic_t netfs_n_wh_write_failed;
int netfs_stats_show(struct seq_file *m, void *v)
{
seq_printf(m, "Netfs : DR=%u DW=%u RA=%u RP=%u WB=%u WBZ=%u\n",
seq_printf(m, "Netfs : DR=%u RA=%u RF=%u WB=%u WBZ=%u\n",
atomic_read(&netfs_n_rh_dio_read),
atomic_read(&netfs_n_rh_dio_write),
atomic_read(&netfs_n_rh_readahead),
atomic_read(&netfs_n_rh_readpage),
atomic_read(&netfs_n_rh_read_folio),
atomic_read(&netfs_n_rh_write_begin),
atomic_read(&netfs_n_rh_write_zskip));
seq_printf(m, "Netfs : BW=%u WT=%u DW=%u WP=%u\n",
atomic_read(&netfs_n_wh_buffered_write),
atomic_read(&netfs_n_wh_writethrough),
atomic_read(&netfs_n_wh_dio_write),
atomic_read(&netfs_n_wh_writepages));
seq_printf(m, "Netfs : ZR=%u sh=%u sk=%u\n",
atomic_read(&netfs_n_rh_zero),
atomic_read(&netfs_n_rh_short_read),

808
fs/netfs/write_collect.c Normal file
View File

@ -0,0 +1,808 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Network filesystem write subrequest result collection, assessment
* and retrying.
*
* Copyright (C) 2024 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include "internal.h"
/* Notes made in the collector */
#define HIT_PENDING 0x01 /* A front op was still pending */
#define SOME_EMPTY 0x02 /* One of more streams are empty */
#define ALL_EMPTY 0x04 /* All streams are empty */
#define MAYBE_DISCONTIG 0x08 /* A front op may be discontiguous (rounded to PAGE_SIZE) */
#define NEED_REASSESS 0x10 /* Need to loop round and reassess */
#define REASSESS_DISCONTIG 0x20 /* Reassess discontiguity if contiguity advances */
#define MADE_PROGRESS 0x40 /* Made progress cleaning up a stream or the folio set */
#define BUFFERED 0x80 /* The pagecache needs cleaning up */
#define NEED_RETRY 0x100 /* A front op requests retrying */
#define SAW_FAILURE 0x200 /* One stream or hit a permanent failure */
/*
* Successful completion of write of a folio to the server and/or cache. Note
* that we are not allowed to lock the folio here on pain of deadlocking with
* truncate.
*/
int netfs_folio_written_back(struct folio *folio)
{
enum netfs_folio_trace why = netfs_folio_trace_clear;
struct netfs_folio *finfo;
struct netfs_group *group = NULL;
int gcount = 0;
if ((finfo = netfs_folio_info(folio))) {
/* Streaming writes cannot be redirtied whilst under writeback,
* so discard the streaming record.
*/
folio_detach_private(folio);
group = finfo->netfs_group;
gcount++;
kfree(finfo);
why = netfs_folio_trace_clear_s;
goto end_wb;
}
if ((group = netfs_folio_group(folio))) {
if (group == NETFS_FOLIO_COPY_TO_CACHE) {
why = netfs_folio_trace_clear_cc;
folio_detach_private(folio);
goto end_wb;
}
/* Need to detach the group pointer if the page didn't get
* redirtied. If it has been redirtied, then it must be within
* the same group.
*/
why = netfs_folio_trace_redirtied;
if (!folio_test_dirty(folio)) {
folio_detach_private(folio);
gcount++;
why = netfs_folio_trace_clear_g;
}
}
end_wb:
trace_netfs_folio(folio, why);
folio_end_writeback(folio);
return gcount;
}
/*
* Get hold of a folio we have under writeback. We don't want to get the
* refcount on it.
*/
static struct folio *netfs_writeback_lookup_folio(struct netfs_io_request *wreq, loff_t pos)
{
XA_STATE(xas, &wreq->mapping->i_pages, pos / PAGE_SIZE);
struct folio *folio;
rcu_read_lock();
for (;;) {
xas_reset(&xas);
folio = xas_load(&xas);
if (xas_retry(&xas, folio))
continue;
if (!folio || xa_is_value(folio))
kdebug("R=%08x: folio %lx (%llx) not present",
wreq->debug_id, xas.xa_index, pos / PAGE_SIZE);
BUG_ON(!folio || xa_is_value(folio));
if (folio == xas_reload(&xas))
break;
}
rcu_read_unlock();
if (WARN_ONCE(!folio_test_writeback(folio),
"R=%08x: folio %lx is not under writeback\n",
wreq->debug_id, folio->index)) {
trace_netfs_folio(folio, netfs_folio_trace_not_under_wback);
}
return folio;
}
/*
* Unlock any folios we've finished with.
*/
static void netfs_writeback_unlock_folios(struct netfs_io_request *wreq,
unsigned long long collected_to,
unsigned int *notes)
{
for (;;) {
struct folio *folio;
struct netfs_folio *finfo;
unsigned long long fpos, fend;
size_t fsize, flen;
folio = netfs_writeback_lookup_folio(wreq, wreq->cleaned_to);
fpos = folio_pos(folio);
fsize = folio_size(folio);
finfo = netfs_folio_info(folio);
flen = finfo ? finfo->dirty_offset + finfo->dirty_len : fsize;
fend = min_t(unsigned long long, fpos + flen, wreq->i_size);
trace_netfs_collect_folio(wreq, folio, fend, collected_to);
if (fpos + fsize > wreq->contiguity) {
trace_netfs_collect_contig(wreq, fpos + fsize,
netfs_contig_trace_unlock);
wreq->contiguity = fpos + fsize;
}
/* Unlock any folio we've transferred all of. */
if (collected_to < fend)
break;
wreq->nr_group_rel += netfs_folio_written_back(folio);
wreq->cleaned_to = fpos + fsize;
*notes |= MADE_PROGRESS;
if (fpos + fsize >= collected_to)
break;
}
}
/*
* Perform retries on the streams that need it.
*/
static void netfs_retry_write_stream(struct netfs_io_request *wreq,
struct netfs_io_stream *stream)
{
struct list_head *next;
_enter("R=%x[%x:]", wreq->debug_id, stream->stream_nr);
if (list_empty(&stream->subrequests))
return;
if (stream->source == NETFS_UPLOAD_TO_SERVER &&
wreq->netfs_ops->retry_request)
wreq->netfs_ops->retry_request(wreq, stream);
if (unlikely(stream->failed))
return;
/* If there's no renegotiation to do, just resend each failed subreq. */
if (!stream->prepare_write) {
struct netfs_io_subrequest *subreq;
list_for_each_entry(subreq, &stream->subrequests, rreq_link) {
if (test_bit(NETFS_SREQ_FAILED, &subreq->flags))
break;
if (__test_and_clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) {
__set_bit(NETFS_SREQ_RETRYING, &subreq->flags);
netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
netfs_reissue_write(stream, subreq);
}
}
return;
}
next = stream->subrequests.next;
do {
struct netfs_io_subrequest *subreq = NULL, *from, *to, *tmp;
unsigned long long start, len;
size_t part;
bool boundary = false;
/* Go through the stream and find the next span of contiguous
* data that we then rejig (cifs, for example, needs the wsize
* renegotiating) and reissue.
*/
from = list_entry(next, struct netfs_io_subrequest, rreq_link);
to = from;
start = from->start + from->transferred;
len = from->len - from->transferred;
if (test_bit(NETFS_SREQ_FAILED, &from->flags) ||
!test_bit(NETFS_SREQ_NEED_RETRY, &from->flags))
return;
list_for_each_continue(next, &stream->subrequests) {
subreq = list_entry(next, struct netfs_io_subrequest, rreq_link);
if (subreq->start + subreq->transferred != start + len ||
test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags) ||
!test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags))
break;
to = subreq;
len += to->len;
}
/* Work through the sublist. */
subreq = from;
list_for_each_entry_from(subreq, &stream->subrequests, rreq_link) {
if (!len)
break;
/* Renegotiate max_len (wsize) */
trace_netfs_sreq(subreq, netfs_sreq_trace_retry);
__clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
__set_bit(NETFS_SREQ_RETRYING, &subreq->flags);
stream->prepare_write(subreq);
part = min(len, subreq->max_len);
subreq->len = part;
subreq->start = start;
subreq->transferred = 0;
len -= part;
start += part;
if (len && subreq == to &&
__test_and_clear_bit(NETFS_SREQ_BOUNDARY, &to->flags))
boundary = true;
netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
netfs_reissue_write(stream, subreq);
if (subreq == to)
break;
}
/* If we managed to use fewer subreqs, we can discard the
* excess; if we used the same number, then we're done.
*/
if (!len) {
if (subreq == to)
continue;
list_for_each_entry_safe_from(subreq, tmp,
&stream->subrequests, rreq_link) {
trace_netfs_sreq(subreq, netfs_sreq_trace_discard);
list_del(&subreq->rreq_link);
netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done);
if (subreq == to)
break;
}
continue;
}
/* We ran out of subrequests, so we need to allocate some more
* and insert them after.
*/
do {
subreq = netfs_alloc_subrequest(wreq);
subreq->source = to->source;
subreq->start = start;
subreq->max_len = len;
subreq->max_nr_segs = INT_MAX;
subreq->debug_index = atomic_inc_return(&wreq->subreq_counter);
subreq->stream_nr = to->stream_nr;
__set_bit(NETFS_SREQ_RETRYING, &subreq->flags);
trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index,
refcount_read(&subreq->ref),
netfs_sreq_trace_new);
netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
list_add(&subreq->rreq_link, &to->rreq_link);
to = list_next_entry(to, rreq_link);
trace_netfs_sreq(subreq, netfs_sreq_trace_retry);
switch (stream->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload);
subreq->max_len = min(len, wreq->wsize);
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write);
break;
default:
WARN_ON_ONCE(1);
}
stream->prepare_write(subreq);
part = min(len, subreq->max_len);
subreq->len = subreq->transferred + part;
len -= part;
start += part;
if (!len && boundary) {
__set_bit(NETFS_SREQ_BOUNDARY, &to->flags);
boundary = false;
}
netfs_reissue_write(stream, subreq);
if (!len)
break;
} while (len);
} while (!list_is_head(next, &stream->subrequests));
}
/*
* Perform retries on the streams that need it. If we're doing content
* encryption and the server copy changed due to a third-party write, we may
* need to do an RMW cycle and also rewrite the data to the cache.
*/
static void netfs_retry_writes(struct netfs_io_request *wreq)
{
struct netfs_io_subrequest *subreq;
struct netfs_io_stream *stream;
int s;
/* Wait for all outstanding I/O to quiesce before performing retries as
* we may need to renegotiate the I/O sizes.
*/
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (!stream->active)
continue;
list_for_each_entry(subreq, &stream->subrequests, rreq_link) {
wait_on_bit(&subreq->flags, NETFS_SREQ_IN_PROGRESS,
TASK_UNINTERRUPTIBLE);
}
}
// TODO: Enc: Fetch changed partial pages
// TODO: Enc: Reencrypt content if needed.
// TODO: Enc: Wind back transferred point.
// TODO: Enc: Mark cache pages for retry.
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->need_retry) {
stream->need_retry = false;
netfs_retry_write_stream(wreq, stream);
}
}
}
/*
* Collect and assess the results of various write subrequests. We may need to
* retry some of the results - or even do an RMW cycle for content crypto.
*
* Note that we have a number of parallel, overlapping lists of subrequests,
* one to the server and one to the local cache for example, which may not be
* the same size or starting position and may not even correspond in boundary
* alignment.
*/
static void netfs_collect_write_results(struct netfs_io_request *wreq)
{
struct netfs_io_subrequest *front, *remove;
struct netfs_io_stream *stream;
unsigned long long collected_to;
unsigned int notes;
int s;
_enter("%llx-%llx", wreq->start, wreq->start + wreq->len);
trace_netfs_collect(wreq);
trace_netfs_rreq(wreq, netfs_rreq_trace_collect);
reassess_streams:
smp_rmb();
collected_to = ULLONG_MAX;
if (wreq->origin == NETFS_WRITEBACK)
notes = ALL_EMPTY | BUFFERED | MAYBE_DISCONTIG;
else if (wreq->origin == NETFS_WRITETHROUGH)
notes = ALL_EMPTY | BUFFERED;
else
notes = ALL_EMPTY;
/* Remove completed subrequests from the front of the streams and
* advance the completion point on each stream. We stop when we hit
* something that's in progress. The issuer thread may be adding stuff
* to the tail whilst we're doing this.
*
* We must not, however, merge in discontiguities that span whole
* folios that aren't under writeback. This is made more complicated
* by the folios in the gap being of unpredictable sizes - if they even
* exist - but we don't want to look them up.
*/
for (s = 0; s < NR_IO_STREAMS; s++) {
loff_t rstart, rend;
stream = &wreq->io_streams[s];
/* Read active flag before list pointers */
if (!smp_load_acquire(&stream->active))
continue;
front = stream->front;
while (front) {
trace_netfs_collect_sreq(wreq, front);
//_debug("sreq [%x] %llx %zx/%zx",
// front->debug_index, front->start, front->transferred, front->len);
/* Stall if there may be a discontinuity. */
rstart = round_down(front->start, PAGE_SIZE);
if (rstart > wreq->contiguity) {
if (wreq->contiguity > stream->collected_to) {
trace_netfs_collect_gap(wreq, stream,
wreq->contiguity, 'D');
stream->collected_to = wreq->contiguity;
}
notes |= REASSESS_DISCONTIG;
break;
}
rend = round_up(front->start + front->len, PAGE_SIZE);
if (rend > wreq->contiguity) {
trace_netfs_collect_contig(wreq, rend,
netfs_contig_trace_collect);
wreq->contiguity = rend;
if (notes & REASSESS_DISCONTIG)
notes |= NEED_REASSESS;
}
notes &= ~MAYBE_DISCONTIG;
/* Stall if the front is still undergoing I/O. */
if (test_bit(NETFS_SREQ_IN_PROGRESS, &front->flags)) {
notes |= HIT_PENDING;
break;
}
smp_rmb(); /* Read counters after I-P flag. */
if (stream->failed) {
stream->collected_to = front->start + front->len;
notes |= MADE_PROGRESS | SAW_FAILURE;
goto cancel;
}
if (front->start + front->transferred > stream->collected_to) {
stream->collected_to = front->start + front->transferred;
stream->transferred = stream->collected_to - wreq->start;
notes |= MADE_PROGRESS;
}
if (test_bit(NETFS_SREQ_FAILED, &front->flags)) {
stream->failed = true;
stream->error = front->error;
if (stream->source == NETFS_UPLOAD_TO_SERVER)
mapping_set_error(wreq->mapping, front->error);
notes |= NEED_REASSESS | SAW_FAILURE;
break;
}
if (front->transferred < front->len) {
stream->need_retry = true;
notes |= NEED_RETRY | MADE_PROGRESS;
break;
}
cancel:
/* Remove if completely consumed. */
spin_lock(&wreq->lock);
remove = front;
list_del_init(&front->rreq_link);
front = list_first_entry_or_null(&stream->subrequests,
struct netfs_io_subrequest, rreq_link);
stream->front = front;
if (!front) {
unsigned long long jump_to = atomic64_read(&wreq->issued_to);
if (stream->collected_to < jump_to) {
trace_netfs_collect_gap(wreq, stream, jump_to, 'A');
stream->collected_to = jump_to;
}
}
spin_unlock(&wreq->lock);
netfs_put_subrequest(remove, false,
notes & SAW_FAILURE ?
netfs_sreq_trace_put_cancel :
netfs_sreq_trace_put_done);
}
if (front)
notes &= ~ALL_EMPTY;
else
notes |= SOME_EMPTY;
if (stream->collected_to < collected_to)
collected_to = stream->collected_to;
}
if (collected_to != ULLONG_MAX && collected_to > wreq->collected_to)
wreq->collected_to = collected_to;
/* If we have an empty stream, we need to jump it forward over any gap
* otherwise the collection point will never advance.
*
* Note that the issuer always adds to the stream with the lowest
* so-far submitted start, so if we see two consecutive subreqs in one
* stream with nothing between then in another stream, then the second
* stream has a gap that can be jumped.
*/
if (notes & SOME_EMPTY) {
unsigned long long jump_to = wreq->start + wreq->len;
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->active &&
stream->front &&
stream->front->start < jump_to)
jump_to = stream->front->start;
}
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->active &&
!stream->front &&
stream->collected_to < jump_to) {
trace_netfs_collect_gap(wreq, stream, jump_to, 'B');
stream->collected_to = jump_to;
}
}
}
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->active)
trace_netfs_collect_stream(wreq, stream);
}
trace_netfs_collect_state(wreq, wreq->collected_to, notes);
/* Unlock any folios that we have now finished with. */
if (notes & BUFFERED) {
unsigned long long clean_to = min(wreq->collected_to, wreq->contiguity);
if (wreq->cleaned_to < clean_to)
netfs_writeback_unlock_folios(wreq, clean_to, &notes);
} else {
wreq->cleaned_to = wreq->collected_to;
}
// TODO: Discard encryption buffers
/* If all streams are discontiguous with the last folio we cleared, we
* may need to skip a set of folios.
*/
if ((notes & (MAYBE_DISCONTIG | ALL_EMPTY)) == MAYBE_DISCONTIG) {
unsigned long long jump_to = ULLONG_MAX;
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->active && stream->front &&
stream->front->start < jump_to)
jump_to = stream->front->start;
}
trace_netfs_collect_contig(wreq, jump_to, netfs_contig_trace_jump);
wreq->contiguity = jump_to;
wreq->cleaned_to = jump_to;
wreq->collected_to = jump_to;
for (s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->collected_to < jump_to)
stream->collected_to = jump_to;
}
//cond_resched();
notes |= MADE_PROGRESS;
goto reassess_streams;
}
if (notes & NEED_RETRY)
goto need_retry;
if ((notes & MADE_PROGRESS) && test_bit(NETFS_RREQ_PAUSE, &wreq->flags)) {
trace_netfs_rreq(wreq, netfs_rreq_trace_unpause);
clear_bit_unlock(NETFS_RREQ_PAUSE, &wreq->flags);
wake_up_bit(&wreq->flags, NETFS_RREQ_PAUSE);
}
if (notes & NEED_REASSESS) {
//cond_resched();
goto reassess_streams;
}
if (notes & MADE_PROGRESS) {
//cond_resched();
goto reassess_streams;
}
out:
netfs_put_group_many(wreq->group, wreq->nr_group_rel);
wreq->nr_group_rel = 0;
_leave(" = %x", notes);
return;
need_retry:
/* Okay... We're going to have to retry one or both streams. Note
* that any partially completed op will have had any wholly transferred
* folios removed from it.
*/
_debug("retry");
netfs_retry_writes(wreq);
goto out;
}
/*
* Perform the collection of subrequests, folios and encryption buffers.
*/
void netfs_write_collection_worker(struct work_struct *work)
{
struct netfs_io_request *wreq = container_of(work, struct netfs_io_request, work);
struct netfs_inode *ictx = netfs_inode(wreq->inode);
size_t transferred;
int s;
_enter("R=%x", wreq->debug_id);
netfs_see_request(wreq, netfs_rreq_trace_see_work);
if (!test_bit(NETFS_RREQ_IN_PROGRESS, &wreq->flags)) {
netfs_put_request(wreq, false, netfs_rreq_trace_put_work);
return;
}
netfs_collect_write_results(wreq);
/* We're done when the app thread has finished posting subreqs and all
* the queues in all the streams are empty.
*/
if (!test_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags)) {
netfs_put_request(wreq, false, netfs_rreq_trace_put_work);
return;
}
smp_rmb(); /* Read ALL_QUEUED before lists. */
transferred = LONG_MAX;
for (s = 0; s < NR_IO_STREAMS; s++) {
struct netfs_io_stream *stream = &wreq->io_streams[s];
if (!stream->active)
continue;
if (!list_empty(&stream->subrequests)) {
netfs_put_request(wreq, false, netfs_rreq_trace_put_work);
return;
}
if (stream->transferred < transferred)
transferred = stream->transferred;
}
/* Okay, declare that all I/O is complete. */
wreq->transferred = transferred;
trace_netfs_rreq(wreq, netfs_rreq_trace_write_done);
if (wreq->io_streams[1].active &&
wreq->io_streams[1].failed) {
/* Cache write failure doesn't prevent writeback completion
* unless we're in disconnected mode.
*/
ictx->ops->invalidate_cache(wreq);
}
if (wreq->cleanup)
wreq->cleanup(wreq);
if (wreq->origin == NETFS_DIO_WRITE &&
wreq->mapping->nrpages) {
/* mmap may have got underfoot and we may now have folios
* locally covering the region we just wrote. Attempt to
* discard the folios, but leave in place any modified locally.
* ->write_iter() is prevented from interfering by the DIO
* counter.
*/
pgoff_t first = wreq->start >> PAGE_SHIFT;
pgoff_t last = (wreq->start + wreq->transferred - 1) >> PAGE_SHIFT;
invalidate_inode_pages2_range(wreq->mapping, first, last);
}
if (wreq->origin == NETFS_DIO_WRITE)
inode_dio_end(wreq->inode);
_debug("finished");
trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip);
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &wreq->flags);
wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS);
if (wreq->iocb) {
wreq->iocb->ki_pos += wreq->transferred;
if (wreq->iocb->ki_complete)
wreq->iocb->ki_complete(
wreq->iocb, wreq->error ? wreq->error : wreq->transferred);
wreq->iocb = VFS_PTR_POISON;
}
netfs_clear_subrequests(wreq, false);
netfs_put_request(wreq, false, netfs_rreq_trace_put_work_complete);
}
/*
* Wake the collection work item.
*/
void netfs_wake_write_collector(struct netfs_io_request *wreq, bool was_async)
{
if (!work_pending(&wreq->work)) {
netfs_get_request(wreq, netfs_rreq_trace_get_work);
if (!queue_work(system_unbound_wq, &wreq->work))
netfs_put_request(wreq, was_async, netfs_rreq_trace_put_work_nq);
}
}
/**
* netfs_write_subrequest_terminated - Note the termination of a write operation.
* @_op: The I/O request that has terminated.
* @transferred_or_error: The amount of data transferred or an error code.
* @was_async: The termination was asynchronous
*
* This tells the library that a contributory write I/O operation has
* terminated, one way or another, and that it should collect the results.
*
* The caller indicates in @transferred_or_error the outcome of the operation,
* supplying a positive value to indicate the number of bytes transferred or a
* negative error code. The library will look after reissuing I/O operations
* as appropriate and writing downloaded data to the cache.
*
* If @was_async is true, the caller might be running in softirq or interrupt
* context and we can't sleep.
*
* When this is called, ownership of the subrequest is transferred back to the
* library, along with a ref.
*
* Note that %_op is a void* so that the function can be passed to
* kiocb::term_func without the need for a casting wrapper.
*/
void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
bool was_async)
{
struct netfs_io_subrequest *subreq = _op;
struct netfs_io_request *wreq = subreq->rreq;
struct netfs_io_stream *stream = &wreq->io_streams[subreq->stream_nr];
_enter("%x[%x] %zd", wreq->debug_id, subreq->debug_index, transferred_or_error);
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload_done);
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write_done);
break;
case NETFS_INVALID_WRITE:
break;
default:
BUG();
}
if (IS_ERR_VALUE(transferred_or_error)) {
subreq->error = transferred_or_error;
if (subreq->error == -EAGAIN)
set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
else
set_bit(NETFS_SREQ_FAILED, &subreq->flags);
trace_netfs_failure(wreq, subreq, transferred_or_error, netfs_fail_write);
switch (subreq->source) {
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write_failed);
break;
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload_failed);
break;
default:
break;
}
trace_netfs_rreq(wreq, netfs_rreq_trace_set_pause);
set_bit(NETFS_RREQ_PAUSE, &wreq->flags);
} else {
if (WARN(transferred_or_error > subreq->len - subreq->transferred,
"Subreq excess write: R=%x[%x] %zd > %zu - %zu",
wreq->debug_id, subreq->debug_index,
transferred_or_error, subreq->len, subreq->transferred))
transferred_or_error = subreq->len - subreq->transferred;
subreq->error = 0;
subreq->transferred += transferred_or_error;
if (subreq->transferred < subreq->len)
set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);
}
trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
clear_bit_unlock(NETFS_SREQ_IN_PROGRESS, &subreq->flags);
wake_up_bit(&subreq->flags, NETFS_SREQ_IN_PROGRESS);
/* If we are at the head of the queue, wake up the collector,
* transferring a ref to it if we were the ones to do so.
*/
if (list_is_first(&subreq->rreq_link, &stream->subrequests))
netfs_wake_write_collector(wreq, was_async);
netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
}
EXPORT_SYMBOL(netfs_write_subrequest_terminated);

684
fs/netfs/write_issue.c Normal file
View File

@ -0,0 +1,684 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Network filesystem high-level (buffered) writeback.
*
* Copyright (C) 2024 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
*
* To support network filesystems with local caching, we manage a situation
* that can be envisioned like the following:
*
* +---+---+-----+-----+---+----------+
* Folios: | | | | | | |
* +---+---+-----+-----+---+----------+
*
* +------+------+ +----+----+
* Upload: | | |.....| | |
* (Stream 0) +------+------+ +----+----+
*
* +------+------+------+------+------+
* Cache: | | | | | |
* (Stream 1) +------+------+------+------+------+
*
* Where we have a sequence of folios of varying sizes that we need to overlay
* with multiple parallel streams of I/O requests, where the I/O requests in a
* stream may also be of various sizes (in cifs, for example, the sizes are
* negotiated with the server; in something like ceph, they may represent the
* sizes of storage objects).
*
* The sequence in each stream may contain gaps and noncontiguous subrequests
* may be glued together into single vectored write RPCs.
*/
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include "internal.h"
/*
* Kill all dirty folios in the event of an unrecoverable error, starting with
* a locked folio we've already obtained from writeback_iter().
*/
static void netfs_kill_dirty_pages(struct address_space *mapping,
struct writeback_control *wbc,
struct folio *folio)
{
int error = 0;
do {
enum netfs_folio_trace why = netfs_folio_trace_kill;
struct netfs_group *group = NULL;
struct netfs_folio *finfo = NULL;
void *priv;
priv = folio_detach_private(folio);
if (priv) {
finfo = __netfs_folio_info(priv);
if (finfo) {
/* Kill folio from streaming write. */
group = finfo->netfs_group;
why = netfs_folio_trace_kill_s;
} else {
group = priv;
if (group == NETFS_FOLIO_COPY_TO_CACHE) {
/* Kill copy-to-cache folio */
why = netfs_folio_trace_kill_cc;
group = NULL;
} else {
/* Kill folio with group */
why = netfs_folio_trace_kill_g;
}
}
}
trace_netfs_folio(folio, why);
folio_start_writeback(folio);
folio_unlock(folio);
folio_end_writeback(folio);
netfs_put_group(group);
kfree(finfo);
} while ((folio = writeback_iter(mapping, wbc, folio, &error)));
}
/*
* Create a write request and set it up appropriately for the origin type.
*/
struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
struct file *file,
loff_t start,
enum netfs_io_origin origin)
{
struct netfs_io_request *wreq;
struct netfs_inode *ictx;
wreq = netfs_alloc_request(mapping, file, start, 0, origin);
if (IS_ERR(wreq))
return wreq;
_enter("R=%x", wreq->debug_id);
ictx = netfs_inode(wreq->inode);
if (test_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags))
fscache_begin_write_operation(&wreq->cache_resources, netfs_i_cookie(ictx));
wreq->contiguity = wreq->start;
wreq->cleaned_to = wreq->start;
INIT_WORK(&wreq->work, netfs_write_collection_worker);
wreq->io_streams[0].stream_nr = 0;
wreq->io_streams[0].source = NETFS_UPLOAD_TO_SERVER;
wreq->io_streams[0].prepare_write = ictx->ops->prepare_write;
wreq->io_streams[0].issue_write = ictx->ops->issue_write;
wreq->io_streams[0].collected_to = start;
wreq->io_streams[0].transferred = LONG_MAX;
wreq->io_streams[1].stream_nr = 1;
wreq->io_streams[1].source = NETFS_WRITE_TO_CACHE;
wreq->io_streams[1].collected_to = start;
wreq->io_streams[1].transferred = LONG_MAX;
if (fscache_resources_valid(&wreq->cache_resources)) {
wreq->io_streams[1].avail = true;
wreq->io_streams[1].prepare_write = wreq->cache_resources.ops->prepare_write_subreq;
wreq->io_streams[1].issue_write = wreq->cache_resources.ops->issue_write;
}
return wreq;
}
/**
* netfs_prepare_write_failed - Note write preparation failed
* @subreq: The subrequest to mark
*
* Mark a subrequest to note that preparation for write failed.
*/
void netfs_prepare_write_failed(struct netfs_io_subrequest *subreq)
{
__set_bit(NETFS_SREQ_FAILED, &subreq->flags);
trace_netfs_sreq(subreq, netfs_sreq_trace_prep_failed);
}
EXPORT_SYMBOL(netfs_prepare_write_failed);
/*
* Prepare a write subrequest. We need to allocate a new subrequest
* if we don't have one.
*/
static void netfs_prepare_write(struct netfs_io_request *wreq,
struct netfs_io_stream *stream,
loff_t start)
{
struct netfs_io_subrequest *subreq;
subreq = netfs_alloc_subrequest(wreq);
subreq->source = stream->source;
subreq->start = start;
subreq->max_len = ULONG_MAX;
subreq->max_nr_segs = INT_MAX;
subreq->stream_nr = stream->stream_nr;
_enter("R=%x[%x]", wreq->debug_id, subreq->debug_index);
trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index,
refcount_read(&subreq->ref),
netfs_sreq_trace_new);
trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
switch (stream->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload);
subreq->max_len = wreq->wsize;
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write);
break;
default:
WARN_ON_ONCE(1);
break;
}
if (stream->prepare_write)
stream->prepare_write(subreq);
__set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags);
/* We add to the end of the list whilst the collector may be walking
* the list. The collector only goes nextwards and uses the lock to
* remove entries off of the front.
*/
spin_lock(&wreq->lock);
list_add_tail(&subreq->rreq_link, &stream->subrequests);
if (list_is_first(&subreq->rreq_link, &stream->subrequests)) {
stream->front = subreq;
if (!stream->active) {
stream->collected_to = stream->front->start;
/* Write list pointers before active flag */
smp_store_release(&stream->active, true);
}
}
spin_unlock(&wreq->lock);
stream->construct = subreq;
}
/*
* Set the I/O iterator for the filesystem/cache to use and dispatch the I/O
* operation. The operation may be asynchronous and should call
* netfs_write_subrequest_terminated() when complete.
*/
static void netfs_do_issue_write(struct netfs_io_stream *stream,
struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *wreq = subreq->rreq;
_enter("R=%x[%x],%zx", wreq->debug_id, subreq->debug_index, subreq->len);
if (test_bit(NETFS_SREQ_FAILED, &subreq->flags))
return netfs_write_subrequest_terminated(subreq, subreq->error, false);
// TODO: Use encrypted buffer
if (test_bit(NETFS_RREQ_USE_IO_ITER, &wreq->flags)) {
subreq->io_iter = wreq->io_iter;
iov_iter_advance(&subreq->io_iter,
subreq->start + subreq->transferred - wreq->start);
iov_iter_truncate(&subreq->io_iter,
subreq->len - subreq->transferred);
} else {
iov_iter_xarray(&subreq->io_iter, ITER_SOURCE, &wreq->mapping->i_pages,
subreq->start + subreq->transferred,
subreq->len - subreq->transferred);
}
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
stream->issue_write(subreq);
}
void netfs_reissue_write(struct netfs_io_stream *stream,
struct netfs_io_subrequest *subreq)
{
__set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags);
netfs_do_issue_write(stream, subreq);
}
static void netfs_issue_write(struct netfs_io_request *wreq,
struct netfs_io_stream *stream)
{
struct netfs_io_subrequest *subreq = stream->construct;
if (!subreq)
return;
stream->construct = NULL;
if (subreq->start + subreq->len > wreq->start + wreq->submitted)
wreq->len = wreq->submitted = subreq->start + subreq->len - wreq->start;
netfs_do_issue_write(stream, subreq);
}
/*
* Add data to the write subrequest, dispatching each as we fill it up or if it
* is discontiguous with the previous. We only fill one part at a time so that
* we can avoid overrunning the credits obtained (cifs) and try to parallelise
* content-crypto preparation with network writes.
*/
int netfs_advance_write(struct netfs_io_request *wreq,
struct netfs_io_stream *stream,
loff_t start, size_t len, bool to_eof)
{
struct netfs_io_subrequest *subreq = stream->construct;
size_t part;
if (!stream->avail) {
_leave("no write");
return len;
}
_enter("R=%x[%x]", wreq->debug_id, subreq ? subreq->debug_index : 0);
if (subreq && start != subreq->start + subreq->len) {
netfs_issue_write(wreq, stream);
subreq = NULL;
}
if (!stream->construct)
netfs_prepare_write(wreq, stream, start);
subreq = stream->construct;
part = min(subreq->max_len - subreq->len, len);
_debug("part %zx/%zx %zx/%zx", subreq->len, subreq->max_len, part, len);
subreq->len += part;
subreq->nr_segs++;
if (subreq->len >= subreq->max_len ||
subreq->nr_segs >= subreq->max_nr_segs ||
to_eof) {
netfs_issue_write(wreq, stream);
subreq = NULL;
}
return part;
}
/*
* Write some of a pending folio data back to the server.
*/
static int netfs_write_folio(struct netfs_io_request *wreq,
struct writeback_control *wbc,
struct folio *folio)
{
struct netfs_io_stream *upload = &wreq->io_streams[0];
struct netfs_io_stream *cache = &wreq->io_streams[1];
struct netfs_io_stream *stream;
struct netfs_group *fgroup; /* TODO: Use this with ceph */
struct netfs_folio *finfo;
size_t fsize = folio_size(folio), flen = fsize, foff = 0;
loff_t fpos = folio_pos(folio), i_size;
bool to_eof = false, streamw = false;
bool debug = false;
_enter("");
/* netfs_perform_write() may shift i_size around the page or from out
* of the page to beyond it, but cannot move i_size into or through the
* page since we have it locked.
*/
i_size = i_size_read(wreq->inode);
if (fpos >= i_size) {
/* mmap beyond eof. */
_debug("beyond eof");
folio_start_writeback(folio);
folio_unlock(folio);
wreq->nr_group_rel += netfs_folio_written_back(folio);
netfs_put_group_many(wreq->group, wreq->nr_group_rel);
wreq->nr_group_rel = 0;
return 0;
}
if (fpos + fsize > wreq->i_size)
wreq->i_size = i_size;
fgroup = netfs_folio_group(folio);
finfo = netfs_folio_info(folio);
if (finfo) {
foff = finfo->dirty_offset;
flen = foff + finfo->dirty_len;
streamw = true;
}
if (wreq->origin == NETFS_WRITETHROUGH) {
to_eof = false;
if (flen > i_size - fpos)
flen = i_size - fpos;
} else if (flen > i_size - fpos) {
flen = i_size - fpos;
if (!streamw)
folio_zero_segment(folio, flen, fsize);
to_eof = true;
} else if (flen == i_size - fpos) {
to_eof = true;
}
flen -= foff;
_debug("folio %zx %zx %zx", foff, flen, fsize);
/* Deal with discontinuities in the stream of dirty pages. These can
* arise from a number of sources:
*
* (1) Intervening non-dirty pages from random-access writes, multiple
* flushers writing back different parts simultaneously and manual
* syncing.
*
* (2) Partially-written pages from write-streaming.
*
* (3) Pages that belong to a different write-back group (eg. Ceph
* snapshots).
*
* (4) Actually-clean pages that were marked for write to the cache
* when they were read. Note that these appear as a special
* write-back group.
*/
if (fgroup == NETFS_FOLIO_COPY_TO_CACHE) {
netfs_issue_write(wreq, upload);
} else if (fgroup != wreq->group) {
/* We can't write this page to the server yet. */
kdebug("wrong group");
folio_redirty_for_writepage(wbc, folio);
folio_unlock(folio);
netfs_issue_write(wreq, upload);
netfs_issue_write(wreq, cache);
return 0;
}
if (foff > 0)
netfs_issue_write(wreq, upload);
if (streamw)
netfs_issue_write(wreq, cache);
/* Flip the page to the writeback state and unlock. If we're called
* from write-through, then the page has already been put into the wb
* state.
*/
if (wreq->origin == NETFS_WRITEBACK)
folio_start_writeback(folio);
folio_unlock(folio);
if (fgroup == NETFS_FOLIO_COPY_TO_CACHE) {
if (!fscache_resources_valid(&wreq->cache_resources)) {
trace_netfs_folio(folio, netfs_folio_trace_cancel_copy);
netfs_issue_write(wreq, upload);
netfs_folio_written_back(folio);
return 0;
}
trace_netfs_folio(folio, netfs_folio_trace_store_copy);
} else if (!upload->construct) {
trace_netfs_folio(folio, netfs_folio_trace_store);
} else {
trace_netfs_folio(folio, netfs_folio_trace_store_plus);
}
/* Move the submission point forward to allow for write-streaming data
* not starting at the front of the page. We don't do write-streaming
* with the cache as the cache requires DIO alignment.
*
* Also skip uploading for data that's been read and just needs copying
* to the cache.
*/
for (int s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
stream->submit_max_len = fsize;
stream->submit_off = foff;
stream->submit_len = flen;
if ((stream->source == NETFS_WRITE_TO_CACHE && streamw) ||
(stream->source == NETFS_UPLOAD_TO_SERVER &&
fgroup == NETFS_FOLIO_COPY_TO_CACHE)) {
stream->submit_off = UINT_MAX;
stream->submit_len = 0;
stream->submit_max_len = 0;
}
}
/* Attach the folio to one or more subrequests. For a big folio, we
* could end up with thousands of subrequests if the wsize is small -
* but we might need to wait during the creation of subrequests for
* network resources (eg. SMB credits).
*/
for (;;) {
ssize_t part;
size_t lowest_off = ULONG_MAX;
int choose_s = -1;
/* Always add to the lowest-submitted stream first. */
for (int s = 0; s < NR_IO_STREAMS; s++) {
stream = &wreq->io_streams[s];
if (stream->submit_len > 0 &&
stream->submit_off < lowest_off) {
lowest_off = stream->submit_off;
choose_s = s;
}
}
if (choose_s < 0)
break;
stream = &wreq->io_streams[choose_s];
part = netfs_advance_write(wreq, stream, fpos + stream->submit_off,
stream->submit_len, to_eof);
atomic64_set(&wreq->issued_to, fpos + stream->submit_off);
stream->submit_off += part;
stream->submit_max_len -= part;
if (part > stream->submit_len)
stream->submit_len = 0;
else
stream->submit_len -= part;
if (part > 0)
debug = true;
}
atomic64_set(&wreq->issued_to, fpos + fsize);
if (!debug)
kdebug("R=%x: No submit", wreq->debug_id);
if (flen < fsize)
for (int s = 0; s < NR_IO_STREAMS; s++)
netfs_issue_write(wreq, &wreq->io_streams[s]);
_leave(" = 0");
return 0;
}
/*
* Write some of the pending data back to the server
*/
int netfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct netfs_inode *ictx = netfs_inode(mapping->host);
struct netfs_io_request *wreq = NULL;
struct folio *folio;
int error = 0;
if (wbc->sync_mode == WB_SYNC_ALL)
mutex_lock(&ictx->wb_lock);
else if (!mutex_trylock(&ictx->wb_lock))
return 0;
/* Need the first folio to be able to set up the op. */
folio = writeback_iter(mapping, wbc, NULL, &error);
if (!folio)
goto out;
wreq = netfs_create_write_req(mapping, NULL, folio_pos(folio), NETFS_WRITEBACK);
if (IS_ERR(wreq)) {
error = PTR_ERR(wreq);
goto couldnt_start;
}
trace_netfs_write(wreq, netfs_write_trace_writeback);
netfs_stat(&netfs_n_wh_writepages);
do {
_debug("wbiter %lx %llx", folio->index, wreq->start + wreq->submitted);
/* It appears we don't have to handle cyclic writeback wrapping. */
WARN_ON_ONCE(wreq && folio_pos(folio) < wreq->start + wreq->submitted);
if (netfs_folio_group(folio) != NETFS_FOLIO_COPY_TO_CACHE &&
unlikely(!test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))) {
set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
wreq->netfs_ops->begin_writeback(wreq);
}
error = netfs_write_folio(wreq, wbc, folio);
if (error < 0)
break;
} while ((folio = writeback_iter(mapping, wbc, folio, &error)));
for (int s = 0; s < NR_IO_STREAMS; s++)
netfs_issue_write(wreq, &wreq->io_streams[s]);
smp_wmb(); /* Write lists before ALL_QUEUED. */
set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
mutex_unlock(&ictx->wb_lock);
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
_leave(" = %d", error);
return error;
couldnt_start:
netfs_kill_dirty_pages(mapping, wbc, folio);
out:
mutex_unlock(&ictx->wb_lock);
_leave(" = %d", error);
return error;
}
EXPORT_SYMBOL(netfs_writepages);
/*
* Begin a write operation for writing through the pagecache.
*/
struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len)
{
struct netfs_io_request *wreq = NULL;
struct netfs_inode *ictx = netfs_inode(file_inode(iocb->ki_filp));
mutex_lock(&ictx->wb_lock);
wreq = netfs_create_write_req(iocb->ki_filp->f_mapping, iocb->ki_filp,
iocb->ki_pos, NETFS_WRITETHROUGH);
if (IS_ERR(wreq)) {
mutex_unlock(&ictx->wb_lock);
return wreq;
}
wreq->io_streams[0].avail = true;
trace_netfs_write(wreq, netfs_write_trace_writethrough);
return wreq;
}
/*
* Advance the state of the write operation used when writing through the
* pagecache. Data has been copied into the pagecache that we need to append
* to the request. If we've added more than wsize then we need to create a new
* subrequest.
*/
int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
struct folio *folio, size_t copied, bool to_page_end,
struct folio **writethrough_cache)
{
_enter("R=%x ic=%zu ws=%u cp=%zu tp=%u",
wreq->debug_id, wreq->iter.count, wreq->wsize, copied, to_page_end);
if (!*writethrough_cache) {
if (folio_test_dirty(folio))
/* Sigh. mmap. */
folio_clear_dirty_for_io(folio);
/* We can make multiple writes to the folio... */
folio_start_writeback(folio);
if (wreq->len == 0)
trace_netfs_folio(folio, netfs_folio_trace_wthru);
else
trace_netfs_folio(folio, netfs_folio_trace_wthru_plus);
*writethrough_cache = folio;
}
wreq->len += copied;
if (!to_page_end)
return 0;
*writethrough_cache = NULL;
return netfs_write_folio(wreq, wbc, folio);
}
/*
* End a write operation used when writing through the pagecache.
*/
int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
struct folio *writethrough_cache)
{
struct netfs_inode *ictx = netfs_inode(wreq->inode);
int ret;
_enter("R=%x", wreq->debug_id);
if (writethrough_cache)
netfs_write_folio(wreq, wbc, writethrough_cache);
netfs_issue_write(wreq, &wreq->io_streams[0]);
netfs_issue_write(wreq, &wreq->io_streams[1]);
smp_wmb(); /* Write lists before ALL_QUEUED. */
set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
mutex_unlock(&ictx->wb_lock);
ret = wreq->error;
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
return ret;
}
/*
* Write data to the server without going through the pagecache and without
* writing it to the local cache.
*/
int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t len)
{
struct netfs_io_stream *upload = &wreq->io_streams[0];
ssize_t part;
loff_t start = wreq->start;
int error = 0;
_enter("%zx", len);
if (wreq->origin == NETFS_DIO_WRITE)
inode_dio_begin(wreq->inode);
while (len) {
// TODO: Prepare content encryption
_debug("unbuffered %zx", len);
part = netfs_advance_write(wreq, upload, start, len, false);
start += part;
len -= part;
if (test_bit(NETFS_RREQ_PAUSE, &wreq->flags)) {
trace_netfs_rreq(wreq, netfs_rreq_trace_wait_pause);
wait_on_bit(&wreq->flags, NETFS_RREQ_PAUSE, TASK_UNINTERRUPTIBLE);
}
if (test_bit(NETFS_RREQ_FAILED, &wreq->flags))
break;
}
netfs_issue_write(wreq, upload);
smp_wmb(); /* Write lists before ALL_QUEUED. */
set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
if (list_empty(&upload->subrequests))
netfs_wake_write_collector(wreq, false);
_leave(" = %d", error);
return error;
}

8
fs/nfs/file.c
View File

@ -433,7 +433,7 @@ static void nfs_invalidate_folio(struct folio *folio, size_t offset,
return;
/* Cancel any unstarted writes on this page */
nfs_wb_folio_cancel(inode, folio);
folio_wait_fscache(folio);
folio_wait_private_2(folio); /* [DEPRECATED] */
trace_nfs_invalidate_folio(inode, folio);
}
@ -500,7 +500,7 @@ static int nfs_launder_folio(struct folio *folio)
dfprintk(PAGECACHE, "NFS: launder_folio(%ld, %llu)\n",
inode->i_ino, folio_pos(folio));
folio_wait_fscache(folio);
folio_wait_private_2(folio); /* [DEPRECATED] */
ret = nfs_wb_folio(inode, folio);
trace_nfs_launder_folio_done(inode, folio, ret);
return ret;
@ -593,8 +593,8 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
sb_start_pagefault(inode->i_sb);
/* make sure the cache has finished storing the page */
if (folio_test_fscache(folio) &&
folio_wait_fscache_killable(folio) < 0) {
if (folio_test_private_2(folio) && /* [DEPRECATED] */
folio_wait_private_2_killable(folio) < 0) {
ret = VM_FAULT_RETRY;
goto out;
}

6
fs/nfs/fscache.h
View File

@ -81,6 +81,8 @@ static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
{
netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops, false);
/* [DEPRECATED] Use PG_private_2 to mark folio being written to the cache. */
__set_bit(NETFS_ICTX_USE_PGPRIV2, &nfsi->netfs.flags);
}
extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
@ -101,10 +103,10 @@ extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);
static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
{
if (folio_test_fscache(folio)) {
if (folio_test_private_2(folio)) { /* [DEPRECATED] */
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
folio_wait_fscache(folio);
folio_wait_private_2(folio);
}
fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
return true;

4
fs/nfs/write.c
View File

@ -2120,10 +2120,10 @@ int nfs_migrate_folio(struct address_space *mapping, struct folio *dst,
if (folio_test_private(src))
return -EBUSY;
if (folio_test_fscache(src)) {
if (folio_test_private_2(src)) { /* [DEPRECATED] */
if (mode == MIGRATE_ASYNC)
return -EBUSY;
folio_wait_fscache(src);
folio_wait_private_2(src);
}
return migrate_folio(mapping, dst, src, mode);

16
fs/smb/client/file.c
View File

@ -3032,12 +3032,12 @@ lock_again:
}
if (folio_test_writeback(folio) ||
folio_test_fscache(folio)) {
folio_test_private_2(folio)) { /* [DEPRECATED] */
folio_unlock(folio);
if (wbc->sync_mode != WB_SYNC_NONE) {
folio_wait_writeback(folio);
#ifdef CONFIG_CIFS_FSCACHE
folio_wait_fscache(folio);
folio_wait_private_2(folio);
#endif
goto lock_again;
}
@ -4510,8 +4510,8 @@ static vm_fault_t cifs_page_mkwrite(struct vm_fault *vmf)
* be modified. We then assume the entire folio will need writing back.
*/
#ifdef CONFIG_CIFS_FSCACHE
if (folio_test_fscache(folio) &&
folio_wait_fscache_killable(folio) < 0)
if (folio_test_private_2(folio) && /* [DEPRECATED] */
folio_wait_private_2_killable(folio) < 0)
return VM_FAULT_RETRY;
#endif
@ -4977,10 +4977,10 @@ static bool cifs_release_folio(struct folio *folio, gfp_t gfp)
{
if (folio_test_private(folio))
return 0;
if (folio_test_fscache(folio)) {
if (folio_test_private_2(folio)) { /* [DEPRECATED] */
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
folio_wait_fscache(folio);
folio_wait_private_2(folio);
}
fscache_note_page_release(cifs_inode_cookie(folio->mapping->host));
return true;
@ -4989,7 +4989,7 @@ static bool cifs_release_folio(struct folio *folio, gfp_t gfp)
static void cifs_invalidate_folio(struct folio *folio, size_t offset,
size_t length)
{
folio_wait_fscache(folio);
folio_wait_private_2(folio); /* [DEPRECATED] */
}
static int cifs_launder_folio(struct folio *folio)
@ -5009,7 +5009,7 @@ static int cifs_launder_folio(struct folio *folio)
if (folio_clear_dirty_for_io(folio))
rc = cifs_writepage_locked(&folio->page, &wbc);
folio_wait_fscache(folio);
folio_wait_private_2(folio); /* [DEPRECATED] */
return rc;
}

22
include/linux/fscache.h
View File

@ -172,9 +172,12 @@ extern void __fscache_invalidate(struct fscache_cookie *, const void *, loff_t,
extern int __fscache_begin_read_operation(struct netfs_cache_resources *, struct fscache_cookie *);
extern int __fscache_begin_write_operation(struct netfs_cache_resources *, struct fscache_cookie *);
extern void __fscache_write_to_cache(struct fscache_cookie *, struct address_space *,
loff_t, size_t, loff_t, netfs_io_terminated_t, void *,
bool);
void __fscache_write_to_cache(struct fscache_cookie *cookie,
struct address_space *mapping,
loff_t start, size_t len, loff_t i_size,
netfs_io_terminated_t term_func,
void *term_func_priv,
bool using_pgpriv2, bool cond);
extern void __fscache_clear_page_bits(struct address_space *, loff_t, size_t);
/**
@ -597,7 +600,8 @@ static inline void fscache_clear_page_bits(struct address_space *mapping,
* @i_size: The new size of the inode
* @term_func: The function to call upon completion
* @term_func_priv: The private data for @term_func
* @caching: If PG_fscache has been set
* @using_pgpriv2: If we're using PG_private_2 to mark in-progress write
* @caching: If we actually want to do the caching
*
* Helper function for a netfs to write dirty data from an inode into the cache
* object that's backing it.
@ -608,19 +612,21 @@ static inline void fscache_clear_page_bits(struct address_space *mapping,
* marked with PG_fscache.
*
* If given, @term_func will be called upon completion and supplied with
* @term_func_priv. Note that the PG_fscache flags will have been cleared by
* this point, so the netfs must retain its own pin on the mapping.
* @term_func_priv. Note that if @using_pgpriv2 is set, the PG_private_2 flags
* will have been cleared by this point, so the netfs must retain its own pin
* on the mapping.
*/
static inline void fscache_write_to_cache(struct fscache_cookie *cookie,
struct address_space *mapping,
loff_t start, size_t len, loff_t i_size,
netfs_io_terminated_t term_func,
void *term_func_priv,
bool caching)
bool using_pgpriv2, bool caching)
{
if (caching)
__fscache_write_to_cache(cookie, mapping, start, len, i_size,
term_func, term_func_priv, caching);
term_func, term_func_priv,
using_pgpriv2, caching);
else if (term_func)
term_func(term_func_priv, -ENOBUFS, false);

200
include/linux/netfs.h
View File

@ -20,95 +20,24 @@
#include <linux/uio.h>
enum netfs_sreq_ref_trace;
/*
* Overload PG_private_2 to give us PG_fscache - this is used to indicate that
* a page is currently backed by a local disk cache
*/
#define folio_test_fscache(folio) folio_test_private_2(folio)
#define PageFsCache(page) PagePrivate2((page))
#define SetPageFsCache(page) SetPagePrivate2((page))
#define ClearPageFsCache(page) ClearPagePrivate2((page))
#define TestSetPageFsCache(page) TestSetPagePrivate2((page))
#define TestClearPageFsCache(page) TestClearPagePrivate2((page))
typedef struct mempool_s mempool_t;
/**
* folio_start_fscache - Start an fscache write on a folio.
* folio_start_private_2 - Start an fscache write on a folio. [DEPRECATED]
* @folio: The folio.
*
* Call this function before writing a folio to a local cache. Starting a
* second write before the first one finishes is not allowed.
*
* Note that this should no longer be used.
*/
static inline void folio_start_fscache(struct folio *folio)
static inline void folio_start_private_2(struct folio *folio)
{
VM_BUG_ON_FOLIO(folio_test_private_2(folio), folio);
folio_get(folio);
folio_set_private_2(folio);
}
/**
* folio_end_fscache - End an fscache write on a folio.
* @folio: The folio.
*
* Call this function after the folio has been written to the local cache.
* This will wake any sleepers waiting on this folio.
*/
static inline void folio_end_fscache(struct folio *folio)
{
folio_end_private_2(folio);
}
/**
* folio_wait_fscache - Wait for an fscache write on this folio to end.
* @folio: The folio.
*
* If this folio is currently being written to a local cache, wait for
* the write to finish. Another write may start after this one finishes,
* unless the caller holds the folio lock.
*/
static inline void folio_wait_fscache(struct folio *folio)
{
folio_wait_private_2(folio);
}
/**
* folio_wait_fscache_killable - Wait for an fscache write on this folio to end.
* @folio: The folio.
*
* If this folio is currently being written to a local cache, wait
* for the write to finish or for a fatal signal to be received.
* Another write may start after this one finishes, unless the caller
* holds the folio lock.
*
* Return:
* - 0 if successful.
* - -EINTR if a fatal signal was encountered.
*/
static inline int folio_wait_fscache_killable(struct folio *folio)
{
return folio_wait_private_2_killable(folio);
}
static inline void set_page_fscache(struct page *page)
{
folio_start_fscache(page_folio(page));
}
static inline void end_page_fscache(struct page *page)
{
folio_end_private_2(page_folio(page));
}
static inline void wait_on_page_fscache(struct page *page)
{
folio_wait_private_2(page_folio(page));
}
static inline int wait_on_page_fscache_killable(struct page *page)
{
return folio_wait_private_2_killable(page_folio(page));
}
/* Marks used on xarray-based buffers */
#define NETFS_BUF_PUT_MARK XA_MARK_0 /* - Page needs putting */
#define NETFS_BUF_PAGECACHE_MARK XA_MARK_1 /* - Page needs wb/dirty flag wrangling */
@ -135,6 +64,7 @@ struct netfs_inode {
#if IS_ENABLED(CONFIG_FSCACHE)
struct fscache_cookie *cache;
#endif
struct mutex wb_lock; /* Writeback serialisation */
loff_t remote_i_size; /* Size of the remote file */
loff_t zero_point; /* Size after which we assume there's no data
* on the server */
@ -142,7 +72,8 @@ struct netfs_inode {
#define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
#define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
#define NETFS_ICTX_WRITETHROUGH 2 /* Write-through caching */
#define NETFS_ICTX_NO_WRITE_STREAMING 3 /* Don't engage in write-streaming */
#define NETFS_ICTX_USE_PGPRIV2 31 /* [DEPRECATED] Use PG_private_2 to mark
* write to cache on read */
};
/*
@ -165,14 +96,23 @@ struct netfs_folio {
unsigned int dirty_len; /* Write-streaming dirty data length */
};
#define NETFS_FOLIO_INFO 0x1UL /* OR'd with folio->private. */
#define NETFS_FOLIO_COPY_TO_CACHE ((struct netfs_group *)0x356UL) /* Write to the cache only */
static inline bool netfs_is_folio_info(const void *priv)
{
return (unsigned long)priv & NETFS_FOLIO_INFO;
}
static inline struct netfs_folio *__netfs_folio_info(const void *priv)
{
if (netfs_is_folio_info(priv))
return (struct netfs_folio *)((unsigned long)priv & ~NETFS_FOLIO_INFO);
return NULL;
}
static inline struct netfs_folio *netfs_folio_info(struct folio *folio)
{
void *priv = folio_get_private(folio);
if ((unsigned long)priv & NETFS_FOLIO_INFO)
return (struct netfs_folio *)((unsigned long)priv & ~NETFS_FOLIO_INFO);
return NULL;
return __netfs_folio_info(folio_get_private(folio));
}
static inline struct netfs_group *netfs_folio_group(struct folio *folio)
@ -186,6 +126,33 @@ static inline struct netfs_group *netfs_folio_group(struct folio *folio)
return priv;
}
/*
* Stream of I/O subrequests going to a particular destination, such as the
* server or the local cache. This is mainly intended for writing where we may
* have to write to multiple destinations concurrently.
*/
struct netfs_io_stream {
/* Submission tracking */
struct netfs_io_subrequest *construct; /* Op being constructed */
unsigned int submit_off; /* Folio offset we're submitting from */
unsigned int submit_len; /* Amount of data left to submit */
unsigned int submit_max_len; /* Amount I/O can be rounded up to */
void (*prepare_write)(struct netfs_io_subrequest *subreq);
void (*issue_write)(struct netfs_io_subrequest *subreq);
/* Collection tracking */
struct list_head subrequests; /* Contributory I/O operations */
struct netfs_io_subrequest *front; /* Op being collected */
unsigned long long collected_to; /* Position we've collected results to */
size_t transferred; /* The amount transferred from this stream */
enum netfs_io_source source; /* Where to read from/write to */
unsigned short error; /* Aggregate error for the stream */
unsigned char stream_nr; /* Index of stream in parent table */
bool avail; /* T if stream is available */
bool active; /* T if stream is active */
bool need_retry; /* T if this stream needs retrying */
bool failed; /* T if this stream failed */
};
/*
* Resources required to do operations on a cache.
*/
@ -209,14 +176,17 @@ struct netfs_io_subrequest {
struct work_struct work;
struct list_head rreq_link; /* Link in rreq->subrequests */
struct iov_iter io_iter; /* Iterator for this subrequest */
loff_t start; /* Where to start the I/O */
unsigned long long start; /* Where to start the I/O */
size_t max_len; /* Maximum size of the I/O */
size_t len; /* Size of the I/O */
size_t transferred; /* Amount of data transferred */
refcount_t ref;
short error; /* 0 or error that occurred */
unsigned short debug_index; /* Index in list (for debugging output) */
unsigned int nr_segs; /* Number of segs in io_iter */
unsigned int max_nr_segs; /* 0 or max number of segments in an iterator */
enum netfs_io_source source; /* Where to read from/write to */
unsigned char stream_nr; /* I/O stream this belongs to */
unsigned long flags;
#define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */
#define NETFS_SREQ_CLEAR_TAIL 1 /* Set if the rest of the read should be cleared */
@ -224,15 +194,20 @@ struct netfs_io_subrequest {
#define NETFS_SREQ_SEEK_DATA_READ 3 /* Set if ->read() should SEEK_DATA first */
#define NETFS_SREQ_NO_PROGRESS 4 /* Set if we didn't manage to read any data */
#define NETFS_SREQ_ONDEMAND 5 /* Set if it's from on-demand read mode */
#define NETFS_SREQ_BOUNDARY 6 /* Set if ends on hard boundary (eg. ceph object) */
#define NETFS_SREQ_IN_PROGRESS 8 /* Unlocked when the subrequest completes */
#define NETFS_SREQ_NEED_RETRY 9 /* Set if the filesystem requests a retry */
#define NETFS_SREQ_RETRYING 10 /* Set if we're retrying */
#define NETFS_SREQ_FAILED 11 /* Set if the subreq failed unretryably */
};
enum netfs_io_origin {
NETFS_READAHEAD, /* This read was triggered by readahead */
NETFS_READPAGE, /* This read is a synchronous read */
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
NETFS_COPY_TO_CACHE, /* This write is to copy a read to the cache */
NETFS_WRITEBACK, /* This write was triggered by writepages */
NETFS_WRITETHROUGH, /* This write was made by netfs_perform_write() */
NETFS_LAUNDER_WRITE, /* This is triggered by ->launder_folio() */
NETFS_UNBUFFERED_WRITE, /* This is an unbuffered write */
NETFS_DIO_READ, /* This is a direct I/O read */
NETFS_DIO_WRITE, /* This is a direct I/O write */
@ -254,26 +229,36 @@ struct netfs_io_request {
struct netfs_cache_resources cache_resources;
struct list_head proc_link; /* Link in netfs_iorequests */
struct list_head subrequests; /* Contributory I/O operations */
struct netfs_io_stream io_streams[2]; /* Streams of parallel I/O operations */
#define NR_IO_STREAMS 2 //wreq->nr_io_streams
struct netfs_group *group; /* Writeback group being written back */
struct iov_iter iter; /* Unencrypted-side iterator */
struct iov_iter io_iter; /* I/O (Encrypted-side) iterator */
void *netfs_priv; /* Private data for the netfs */
void *netfs_priv2; /* Private data for the netfs */
struct bio_vec *direct_bv; /* DIO buffer list (when handling iovec-iter) */
unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
unsigned int debug_id;
unsigned int rsize; /* Maximum read size (0 for none) */
unsigned int wsize; /* Maximum write size (0 for none) */
unsigned int subreq_counter; /* Next subreq->debug_index */
atomic_t subreq_counter; /* Next subreq->debug_index */
unsigned int nr_group_rel; /* Number of refs to release on ->group */
spinlock_t lock; /* Lock for queuing subreqs */
atomic_t nr_outstanding; /* Number of ops in progress */
atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
size_t submitted; /* Amount submitted for I/O so far */
size_t len; /* Length of the request */
size_t upper_len; /* Length can be extended to here */
unsigned long long submitted; /* Amount submitted for I/O so far */
unsigned long long len; /* Length of the request */
size_t transferred; /* Amount to be indicated as transferred */
short error; /* 0 or error that occurred */
enum netfs_io_origin origin; /* Origin of the request */
bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */
loff_t i_size; /* Size of the file */
loff_t start; /* Start position */
unsigned long long i_size; /* Size of the file */
unsigned long long start; /* Start position */
atomic64_t issued_to; /* Write issuer folio cursor */
unsigned long long contiguity; /* Tracking for gaps in the writeback sequence */
unsigned long long collected_to; /* Point we've collected to */
unsigned long long cleaned_to; /* Position we've cleaned folios to */
pgoff_t no_unlock_folio; /* Don't unlock this folio after read */
refcount_t ref;
unsigned long flags;
@ -287,6 +272,11 @@ struct netfs_io_request {
#define NETFS_RREQ_UPLOAD_TO_SERVER 8 /* Need to write to the server */
#define NETFS_RREQ_NONBLOCK 9 /* Don't block if possible (O_NONBLOCK) */
#define NETFS_RREQ_BLOCKED 10 /* We blocked */
#define NETFS_RREQ_PAUSE 11 /* Pause subrequest generation */
#define NETFS_RREQ_USE_IO_ITER 12 /* Use ->io_iter rather than ->i_pages */
#define NETFS_RREQ_ALL_QUEUED 13 /* All subreqs are now queued */
#define NETFS_RREQ_USE_PGPRIV2 31 /* [DEPRECATED] Use PG_private_2 to mark
* write to cache on read */
const struct netfs_request_ops *netfs_ops;
void (*cleanup)(struct netfs_io_request *req);
};
@ -295,8 +285,8 @@ struct netfs_io_request {
* Operations the network filesystem can/must provide to the helpers.
*/
struct netfs_request_ops {
unsigned int io_request_size; /* Alloc size for netfs_io_request struct */
unsigned int io_subrequest_size; /* Alloc size for netfs_io_subrequest struct */
mempool_t *request_pool;
mempool_t *subrequest_pool;
int (*init_request)(struct netfs_io_request *rreq, struct file *file);
void (*free_request)(struct netfs_io_request *rreq);
void (*free_subrequest)(struct netfs_io_subrequest *rreq);
@ -314,8 +304,10 @@ struct netfs_request_ops {
void (*update_i_size)(struct inode *inode, loff_t i_size);
/* Write request handling */
void (*create_write_requests)(struct netfs_io_request *wreq,
loff_t start, size_t len);
void (*begin_writeback)(struct netfs_io_request *wreq);
void (*prepare_write)(struct netfs_io_subrequest *subreq);
void (*issue_write)(struct netfs_io_subrequest *subreq);
void (*retry_request)(struct netfs_io_request *wreq, struct netfs_io_stream *stream);
void (*invalidate_cache)(struct netfs_io_request *wreq);
};
@ -350,15 +342,27 @@ struct netfs_cache_ops {
netfs_io_terminated_t term_func,
void *term_func_priv);
/* Write data to the cache from a netfs subrequest. */
void (*issue_write)(struct netfs_io_subrequest *subreq);
/* Expand readahead request */
void (*expand_readahead)(struct netfs_cache_resources *cres,
loff_t *_start, size_t *_len, loff_t i_size);
unsigned long long *_start,
unsigned long long *_len,
unsigned long long i_size);
/* Prepare a read operation, shortening it to a cached/uncached
* boundary as appropriate.
*/
enum netfs_io_source (*prepare_read)(struct netfs_io_subrequest *subreq,
loff_t i_size);
unsigned long long i_size);
/* Prepare a write subrequest, working out if we're allowed to do it
* and finding out the maximum amount of data to gather before
* attempting to submit. If we're not permitted to do it, the
* subrequest should be marked failed.
*/
void (*prepare_write_subreq)(struct netfs_io_subrequest *subreq);
/* Prepare a write operation, working out what part of the write we can
* actually do.
@ -410,7 +414,6 @@ int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc);
void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
bool netfs_release_folio(struct folio *folio, gfp_t gfp);
int netfs_launder_folio(struct folio *folio);
/* VMA operations API. */
vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group);
@ -426,9 +429,7 @@ ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
iov_iter_extraction_t extraction_flags);
size_t netfs_limit_iter(const struct iov_iter *iter, size_t start_offset,
size_t max_size, size_t max_segs);
struct netfs_io_subrequest *netfs_create_write_request(
struct netfs_io_request *wreq, enum netfs_io_source dest,
loff_t start, size_t len, work_func_t worker);
void netfs_prepare_write_failed(struct netfs_io_subrequest *subreq);
void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
bool was_async);
void netfs_queue_write_request(struct netfs_io_subrequest *subreq);
@ -472,6 +473,7 @@ static inline void netfs_inode_init(struct netfs_inode *ctx,
#if IS_ENABLED(CONFIG_FSCACHE)
ctx->cache = NULL;
#endif
mutex_init(&ctx->wb_lock);
/* ->releasepage() drives zero_point */
if (use_zero_point) {
ctx->zero_point = ctx->remote_i_size;

2
include/linux/pagemap.h
View File

@ -40,6 +40,8 @@ int filemap_fdatawait_keep_errors(struct address_space *mapping);
int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend);
int filemap_fdatawait_range_keep_errors(struct address_space *mapping,
loff_t start_byte, loff_t end_byte);
int filemap_invalidate_inode(struct inode *inode, bool flush,
loff_t start, loff_t end);
static inline int filemap_fdatawait(struct address_space *mapping)
{

2
include/net/9p/client.h
View File

@ -207,6 +207,8 @@ int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err
int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
int *err);
int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
struct netfs_io_subrequest;
void p9_client_write_subreq(struct netfs_io_subrequest *subreq);
int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
int p9dirent_read(struct p9_client *clnt, char *buf, int len,
struct p9_dirent *dirent);

249
include/trace/events/netfs.h
View File

@ -24,8 +24,8 @@
E_(netfs_read_trace_write_begin, "WRITEBEGN")
#define netfs_write_traces \
EM(netfs_write_trace_copy_to_cache, "COPY2CACH") \
EM(netfs_write_trace_dio_write, "DIO-WRITE") \
EM(netfs_write_trace_launder, "LAUNDER ") \
EM(netfs_write_trace_unbuffered_write, "UNB-WRITE") \
EM(netfs_write_trace_writeback, "WRITEBACK") \
E_(netfs_write_trace_writethrough, "WRITETHRU")
@ -34,9 +34,9 @@
EM(NETFS_READAHEAD, "RA") \
EM(NETFS_READPAGE, "RP") \
EM(NETFS_READ_FOR_WRITE, "RW") \
EM(NETFS_COPY_TO_CACHE, "CC") \
EM(NETFS_WRITEBACK, "WB") \
EM(NETFS_WRITETHROUGH, "WT") \
EM(NETFS_LAUNDER_WRITE, "LW") \
EM(NETFS_UNBUFFERED_WRITE, "UW") \
EM(NETFS_DIO_READ, "DR") \
E_(NETFS_DIO_WRITE, "DW")
@ -44,14 +44,18 @@
#define netfs_rreq_traces \
EM(netfs_rreq_trace_assess, "ASSESS ") \
EM(netfs_rreq_trace_copy, "COPY ") \
EM(netfs_rreq_trace_collect, "COLLECT") \
EM(netfs_rreq_trace_done, "DONE ") \
EM(netfs_rreq_trace_free, "FREE ") \
EM(netfs_rreq_trace_redirty, "REDIRTY") \
EM(netfs_rreq_trace_resubmit, "RESUBMT") \
EM(netfs_rreq_trace_set_pause, "PAUSE ") \
EM(netfs_rreq_trace_unlock, "UNLOCK ") \
EM(netfs_rreq_trace_unmark, "UNMARK ") \
EM(netfs_rreq_trace_wait_ip, "WAIT-IP") \
EM(netfs_rreq_trace_wait_pause, "WT-PAUS") \
EM(netfs_rreq_trace_wake_ip, "WAKE-IP") \
EM(netfs_rreq_trace_unpause, "UNPAUSE") \
E_(netfs_rreq_trace_write_done, "WR-DONE")
#define netfs_sreq_sources \
@ -64,11 +68,15 @@
E_(NETFS_INVALID_WRITE, "INVL")
#define netfs_sreq_traces \
EM(netfs_sreq_trace_discard, "DSCRD") \
EM(netfs_sreq_trace_download_instead, "RDOWN") \
EM(netfs_sreq_trace_fail, "FAIL ") \
EM(netfs_sreq_trace_free, "FREE ") \
EM(netfs_sreq_trace_limited, "LIMIT") \
EM(netfs_sreq_trace_prepare, "PREP ") \
EM(netfs_sreq_trace_prep_failed, "PRPFL") \
EM(netfs_sreq_trace_resubmit_short, "SHORT") \
EM(netfs_sreq_trace_retry, "RETRY") \
EM(netfs_sreq_trace_submit, "SUBMT") \
EM(netfs_sreq_trace_terminated, "TERM ") \
EM(netfs_sreq_trace_write, "WRITE") \
@ -88,6 +96,7 @@
#define netfs_rreq_ref_traces \
EM(netfs_rreq_trace_get_for_outstanding,"GET OUTSTND") \
EM(netfs_rreq_trace_get_subreq, "GET SUBREQ ") \
EM(netfs_rreq_trace_get_work, "GET WORK ") \
EM(netfs_rreq_trace_put_complete, "PUT COMPLT ") \
EM(netfs_rreq_trace_put_discard, "PUT DISCARD") \
EM(netfs_rreq_trace_put_failed, "PUT FAILED ") \
@ -95,6 +104,8 @@
EM(netfs_rreq_trace_put_return, "PUT RETURN ") \
EM(netfs_rreq_trace_put_subreq, "PUT SUBREQ ") \
EM(netfs_rreq_trace_put_work, "PUT WORK ") \
EM(netfs_rreq_trace_put_work_complete, "PUT WORK CP") \
EM(netfs_rreq_trace_put_work_nq, "PUT WORK NQ") \
EM(netfs_rreq_trace_see_work, "SEE WORK ") \
E_(netfs_rreq_trace_new, "NEW ")
@ -103,11 +114,14 @@
EM(netfs_sreq_trace_get_resubmit, "GET RESUBMIT") \
EM(netfs_sreq_trace_get_short_read, "GET SHORTRD") \
EM(netfs_sreq_trace_new, "NEW ") \
EM(netfs_sreq_trace_put_cancel, "PUT CANCEL ") \
EM(netfs_sreq_trace_put_clear, "PUT CLEAR ") \
EM(netfs_sreq_trace_put_discard, "PUT DISCARD") \
EM(netfs_sreq_trace_put_done, "PUT DONE ") \
EM(netfs_sreq_trace_put_failed, "PUT FAILED ") \
EM(netfs_sreq_trace_put_merged, "PUT MERGED ") \
EM(netfs_sreq_trace_put_no_copy, "PUT NO COPY") \
EM(netfs_sreq_trace_put_oom, "PUT OOM ") \
EM(netfs_sreq_trace_put_wip, "PUT WIP ") \
EM(netfs_sreq_trace_put_work, "PUT WORK ") \
E_(netfs_sreq_trace_put_terminated, "PUT TERM ")
@ -124,24 +138,33 @@
EM(netfs_streaming_filled_page, "mod-streamw-f") \
EM(netfs_streaming_cont_filled_page, "mod-streamw-f+") \
/* The rest are for writeback */ \
EM(netfs_folio_trace_cancel_copy, "cancel-copy") \
EM(netfs_folio_trace_clear, "clear") \
EM(netfs_folio_trace_clear_s, "clear-s") \
EM(netfs_folio_trace_clear_cc, "clear-cc") \
EM(netfs_folio_trace_clear_g, "clear-g") \
EM(netfs_folio_trace_copy_to_cache, "copy") \
EM(netfs_folio_trace_end_copy, "end-copy") \
EM(netfs_folio_trace_clear_s, "clear-s") \
EM(netfs_folio_trace_copy_to_cache, "mark-copy") \
EM(netfs_folio_trace_filled_gaps, "filled-gaps") \
EM(netfs_folio_trace_kill, "kill") \
EM(netfs_folio_trace_launder, "launder") \
EM(netfs_folio_trace_kill_cc, "kill-cc") \
EM(netfs_folio_trace_kill_g, "kill-g") \
EM(netfs_folio_trace_kill_s, "kill-s") \
EM(netfs_folio_trace_mkwrite, "mkwrite") \
EM(netfs_folio_trace_mkwrite_plus, "mkwrite+") \
EM(netfs_folio_trace_not_under_wback, "!wback") \
EM(netfs_folio_trace_read_gaps, "read-gaps") \
EM(netfs_folio_trace_redirty, "redirty") \
EM(netfs_folio_trace_redirtied, "redirtied") \
EM(netfs_folio_trace_store, "store") \
EM(netfs_folio_trace_store_copy, "store-copy") \
EM(netfs_folio_trace_store_plus, "store+") \
EM(netfs_folio_trace_wthru, "wthru") \
E_(netfs_folio_trace_wthru_plus, "wthru+")
#define netfs_collect_contig_traces \
EM(netfs_contig_trace_collect, "Collect") \
EM(netfs_contig_trace_jump, "-->JUMP-->") \
E_(netfs_contig_trace_unlock, "Unlock")
#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
@ -158,6 +181,7 @@ enum netfs_failure { netfs_failures } __mode(byte);
enum netfs_rreq_ref_trace { netfs_rreq_ref_traces } __mode(byte);
enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte);
enum netfs_folio_trace { netfs_folio_traces } __mode(byte);
enum netfs_collect_contig_trace { netfs_collect_contig_traces } __mode(byte);
#endif
@ -179,6 +203,7 @@ netfs_failures;
netfs_rreq_ref_traces;
netfs_sreq_ref_traces;
netfs_folio_traces;
netfs_collect_contig_traces;
/*
* Now redefine the EM() and E_() macros to map the enums to the strings that
@ -279,7 +304,7 @@ TRACE_EVENT(netfs_sreq,
__entry->start = sreq->start;
),
TP_printk("R=%08x[%u] %s %s f=%02x s=%llx %zx/%zx e=%d",
TP_printk("R=%08x[%x] %s %s f=%02x s=%llx %zx/%zx e=%d",
__entry->rreq, __entry->index,
__print_symbolic(__entry->source, netfs_sreq_sources),
__print_symbolic(__entry->what, netfs_sreq_traces),
@ -319,7 +344,7 @@ TRACE_EVENT(netfs_failure,
__entry->start = sreq ? sreq->start : 0;
),
TP_printk("R=%08x[%d] %s f=%02x s=%llx %zx/%zx %s e=%d",
TP_printk("R=%08x[%x] %s f=%02x s=%llx %zx/%zx %s e=%d",
__entry->rreq, __entry->index,
__print_symbolic(__entry->source, netfs_sreq_sources),
__entry->flags,
@ -412,16 +437,18 @@ TRACE_EVENT(netfs_write_iter,
__field(unsigned long long, start )
__field(size_t, len )
__field(unsigned int, flags )
__field(unsigned int, ino )
),
TP_fast_assign(
__entry->start = iocb->ki_pos;
__entry->len = iov_iter_count(from);
__entry->ino = iocb->ki_filp->f_inode->i_ino;
__entry->flags = iocb->ki_flags;
),
TP_printk("WRITE-ITER s=%llx l=%zx f=%x",
__entry->start, __entry->len, __entry->flags)
TP_printk("WRITE-ITER i=%x s=%llx l=%zx f=%x",
__entry->ino, __entry->start, __entry->len, __entry->flags)
);
TRACE_EVENT(netfs_write,
@ -433,9 +460,10 @@ TRACE_EVENT(netfs_write,
TP_STRUCT__entry(
__field(unsigned int, wreq )
__field(unsigned int, cookie )
__field(unsigned int, ino )
__field(enum netfs_write_trace, what )
__field(unsigned long long, start )
__field(size_t, len )
__field(unsigned long long, len )
),
TP_fast_assign(
@ -443,18 +471,213 @@ TRACE_EVENT(netfs_write,
struct fscache_cookie *__cookie = netfs_i_cookie(__ctx);
__entry->wreq = wreq->debug_id;
__entry->cookie = __cookie ? __cookie->debug_id : 0;
__entry->ino = wreq->inode->i_ino;
__entry->what = what;
__entry->start = wreq->start;
__entry->len = wreq->len;
),
TP_printk("R=%08x %s c=%08x by=%llx-%llx",
TP_printk("R=%08x %s c=%08x i=%x by=%llx-%llx",
__entry->wreq,
__print_symbolic(__entry->what, netfs_write_traces),
__entry->cookie,
__entry->ino,
__entry->start, __entry->start + __entry->len - 1)
);
TRACE_EVENT(netfs_collect,
TP_PROTO(const struct netfs_io_request *wreq),
TP_ARGS(wreq),
TP_STRUCT__entry(
__field(unsigned int, wreq )
__field(unsigned int, len )
__field(unsigned long long, transferred )
__field(unsigned long long, start )
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->start = wreq->start;
__entry->len = wreq->len;
__entry->transferred = wreq->transferred;
),
TP_printk("R=%08x s=%llx-%llx",
__entry->wreq,
__entry->start + __entry->transferred,
__entry->start + __entry->len)
);
TRACE_EVENT(netfs_collect_contig,
TP_PROTO(const struct netfs_io_request *wreq, unsigned long long to,
enum netfs_collect_contig_trace type),
TP_ARGS(wreq, to, type),
TP_STRUCT__entry(
__field(unsigned int, wreq)
__field(enum netfs_collect_contig_trace, type)
__field(unsigned long long, contiguity)
__field(unsigned long long, to)
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->type = type;
__entry->contiguity = wreq->contiguity;
__entry->to = to;
),
TP_printk("R=%08x %llx -> %llx %s",
__entry->wreq,
__entry->contiguity,
__entry->to,
__print_symbolic(__entry->type, netfs_collect_contig_traces))
);
TRACE_EVENT(netfs_collect_sreq,
TP_PROTO(const struct netfs_io_request *wreq,
const struct netfs_io_subrequest *subreq),
TP_ARGS(wreq, subreq),
TP_STRUCT__entry(
__field(unsigned int, wreq )
__field(unsigned int, subreq )
__field(unsigned int, stream )
__field(unsigned int, len )
__field(unsigned int, transferred )
__field(unsigned long long, start )
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->subreq = subreq->debug_index;
__entry->stream = subreq->stream_nr;
__entry->start = subreq->start;
__entry->len = subreq->len;
__entry->transferred = subreq->transferred;
),
TP_printk("R=%08x[%u:%02x] s=%llx t=%x/%x",
__entry->wreq, __entry->stream, __entry->subreq,
__entry->start, __entry->transferred, __entry->len)
);
TRACE_EVENT(netfs_collect_folio,
TP_PROTO(const struct netfs_io_request *wreq,
const struct folio *folio,
unsigned long long fend,
unsigned long long collected_to),
TP_ARGS(wreq, folio, fend, collected_to),
TP_STRUCT__entry(
__field(unsigned int, wreq )
__field(unsigned long, index )
__field(unsigned long long, fend )
__field(unsigned long long, cleaned_to )
__field(unsigned long long, collected_to )
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->index = folio->index;
__entry->fend = fend;
__entry->cleaned_to = wreq->cleaned_to;
__entry->collected_to = collected_to;
),
TP_printk("R=%08x ix=%05lx r=%llx-%llx t=%llx/%llx",
__entry->wreq, __entry->index,
(unsigned long long)__entry->index * PAGE_SIZE, __entry->fend,
__entry->cleaned_to, __entry->collected_to)
);
TRACE_EVENT(netfs_collect_state,
TP_PROTO(const struct netfs_io_request *wreq,
unsigned long long collected_to,
unsigned int notes),
TP_ARGS(wreq, collected_to, notes),
TP_STRUCT__entry(
__field(unsigned int, wreq )
__field(unsigned int, notes )
__field(unsigned long long, collected_to )
__field(unsigned long long, cleaned_to )
__field(unsigned long long, contiguity )
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->notes = notes;
__entry->collected_to = collected_to;
__entry->cleaned_to = wreq->cleaned_to;
__entry->contiguity = wreq->contiguity;
),
TP_printk("R=%08x cto=%llx fto=%llx ctg=%llx n=%x",
__entry->wreq, __entry->collected_to,
__entry->cleaned_to, __entry->contiguity,
__entry->notes)
);
TRACE_EVENT(netfs_collect_gap,
TP_PROTO(const struct netfs_io_request *wreq,
const struct netfs_io_stream *stream,
unsigned long long jump_to, char type),
TP_ARGS(wreq, stream, jump_to, type),
TP_STRUCT__entry(
__field(unsigned int, wreq)
__field(unsigned char, stream)
__field(unsigned char, type)
__field(unsigned long long, from)
__field(unsigned long long, to)
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->stream = stream->stream_nr;
__entry->from = stream->collected_to;
__entry->to = jump_to;
__entry->type = type;
),
TP_printk("R=%08x[%x:] %llx->%llx %c",
__entry->wreq, __entry->stream,
__entry->from, __entry->to, __entry->type)
);
TRACE_EVENT(netfs_collect_stream,
TP_PROTO(const struct netfs_io_request *wreq,
const struct netfs_io_stream *stream),
TP_ARGS(wreq, stream),
TP_STRUCT__entry(
__field(unsigned int, wreq)
__field(unsigned char, stream)
__field(unsigned long long, collected_to)
__field(unsigned long long, front)
),
TP_fast_assign(
__entry->wreq = wreq->debug_id;
__entry->stream = stream->stream_nr;
__entry->collected_to = stream->collected_to;
__entry->front = stream->front ? stream->front->start : UINT_MAX;
),
TP_printk("R=%08x[%x:] cto=%llx frn=%llx",
__entry->wreq, __entry->stream,
__entry->collected_to, __entry->front)
);
#undef EM
#undef E_
#endif /* _TRACE_NETFS_H */

60
mm/filemap.c
View File

@ -1540,7 +1540,7 @@ EXPORT_SYMBOL(folio_end_private_2);
* folio_wait_private_2 - Wait for PG_private_2 to be cleared on a folio.
* @folio: The folio to wait on.
*
* Wait for PG_private_2 (aka PG_fscache) to be cleared on a folio.
* Wait for PG_private_2 to be cleared on a folio.
*/
void folio_wait_private_2(struct folio *folio)
{
@ -1553,8 +1553,8 @@ EXPORT_SYMBOL(folio_wait_private_2);
* folio_wait_private_2_killable - Wait for PG_private_2 to be cleared on a folio.
* @folio: The folio to wait on.
*
* Wait for PG_private_2 (aka PG_fscache) to be cleared on a folio or until a
* fatal signal is received by the calling task.
* Wait for PG_private_2 to be cleared on a folio or until a fatal signal is
* received by the calling task.
*
* Return:
* - 0 if successful.
@ -4134,6 +4134,60 @@ bool filemap_release_folio(struct folio *folio, gfp_t gfp)
}
EXPORT_SYMBOL(filemap_release_folio);
/**
* filemap_invalidate_inode - Invalidate/forcibly write back a range of an inode's pagecache
* @inode: The inode to flush
* @flush: Set to write back rather than simply invalidate.
* @start: First byte to in range.
* @end: Last byte in range (inclusive), or LLONG_MAX for everything from start
* onwards.
*
* Invalidate all the folios on an inode that contribute to the specified
* range, possibly writing them back first. Whilst the operation is
* undertaken, the invalidate lock is held to prevent new folios from being
* installed.
*/
int filemap_invalidate_inode(struct inode *inode, bool flush,
loff_t start, loff_t end)
{
struct address_space *mapping = inode->i_mapping;
pgoff_t first = start >> PAGE_SHIFT;
pgoff_t last = end >> PAGE_SHIFT;
pgoff_t nr = end == LLONG_MAX ? ULONG_MAX : last - first + 1;
if (!mapping || !mapping->nrpages || end < start)
goto out;
/* Prevent new folios from being added to the inode. */
filemap_invalidate_lock(mapping);
if (!mapping->nrpages)
goto unlock;
unmap_mapping_pages(mapping, first, nr, false);
/* Write back the data if we're asked to. */
if (flush) {
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.nr_to_write = LONG_MAX,
.range_start = start,
.range_end = end,
};
filemap_fdatawrite_wbc(mapping, &wbc);
}
/* Wait for writeback to complete on all folios and discard. */
truncate_inode_pages_range(mapping, start, end);
unlock:
filemap_invalidate_unlock(mapping);
out:
return filemap_check_errors(mapping);
}
EXPORT_SYMBOL_GPL(filemap_invalidate_inode);
#ifdef CONFIG_CACHESTAT_SYSCALL
/**
* filemap_cachestat() - compute the page cache statistics of a mapping

1
mm/page-writeback.c
View File

@ -2546,6 +2546,7 @@ done:
folio_batch_release(&wbc->fbatch);
return NULL;
}
EXPORT_SYMBOL_GPL(writeback_iter);
/**
* write_cache_pages - walk the list of dirty pages of the given address space and write all of them.

1
net/9p/Kconfig
View File

@ -5,6 +5,7 @@
menuconfig NET_9P
tristate "Plan 9 Resource Sharing Support (9P2000)"
select NETFS_SUPPORT
help
If you say Y here, you will get experimental support for
Plan 9 resource sharing via the 9P2000 protocol.

49
net/9p/client.c
View File

@ -18,6 +18,7 @@
#include <linux/sched/signal.h>
#include <linux/uaccess.h>
#include <linux/uio.h>
#include <linux/netfs.h>
#include <net/9p/9p.h>
#include <linux/parser.h>
#include <linux/seq_file.h>
@ -1661,6 +1662,54 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
}
EXPORT_SYMBOL(p9_client_write);
void
p9_client_write_subreq(struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *wreq = subreq->rreq;
struct p9_fid *fid = wreq->netfs_priv;
struct p9_client *clnt = fid->clnt;
struct p9_req_t *req;
unsigned long long start = subreq->start + subreq->transferred;
int written, len = subreq->len - subreq->transferred;
int err;
p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu len %d\n",
fid->fid, start, len);
/* Don't bother zerocopy for small IO (< 1024) */
if (clnt->trans_mod->zc_request && len > 1024) {
req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, &subreq->io_iter,
0, wreq->len, P9_ZC_HDR_SZ, "dqd",
fid->fid, start, len);
} else {
req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
start, len, &subreq->io_iter);
}
if (IS_ERR(req)) {
netfs_write_subrequest_terminated(subreq, PTR_ERR(req), false);
return;
}
err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &written);
if (err) {
trace_9p_protocol_dump(clnt, &req->rc);
p9_req_put(clnt, req);
netfs_write_subrequest_terminated(subreq, err, false);
return;
}
if (written > len) {
pr_err("bogus RWRITE count (%d > %u)\n", written, len);
written = len;
}
p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", len);
p9_req_put(clnt, req);
netfs_write_subrequest_terminated(subreq, written, false);
}
EXPORT_SYMBOL(p9_client_write_subreq);
struct p9_wstat *p9_client_stat(struct p9_fid *fid)
{
int err;