iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

RxRPC rewrite

Browse Source 
-----BEGIN PGP SIGNATURE-----
 
 iQIVAwUAWG/Ny/Sw1s6N8H32AQIsiw//TbSOwj8w6PqDpN74dNNAjAG7MvzZ+wIf
 cYOkNcWUuEbdypUnJxjyYz6yO7q37M+NPI0AAhVECjyb/Zuy9HMa2h/hLmlMEi4Z
 jfUCUTFbwr+8Z3Rii2P4JWL/fJoGkC9U/nqsL97P6JMXnuX0VIo+6I6VQQymO4GO
 LgWCo9Vif5eRcmc8PpgQB/DabVqAQUuTRYxu3ffFv6jIHg/Qa3W8l0dfwdalmJbR
 XaZbaxA6cdXBv5zYhiId1udql/naJ0o+djKy9Bq9k/RfYLw9DIj6+EWz0CscyKck
 u/ises8Ft0d50zMztNmk9GpJOKeGBJWOypFO3Pq01VT8fZuBzbreXEh7amLswvGg
 5Yhgf5M23+QAxWbp34uMG1a6K4mkCBpOw+4BPGGQ1lyf/kGXB1OZP+1d4FjJptVO
 MQA0ONzqApI8iJuKbtLWJ/UymxxLcDeOGLyruYKXCf+NdSSQowFWlibdF1UEAGP4
 RzOeqzzP8ezkR/PQKZLUxgMKiS0JgHglU6y0vdqC+jpC7ekMtmwllwOowj/ZYdZu
 nsSNh4cXwXub4y4/XSbMSxirxn7c29F0XRHAzWr/LchzZI6rB2WBhwhMEQ++YIEY
 RzOCY3YhxyPxhd3Dq3bjKMXHGVUzORXP/aPJMqs4d93CYCnedW9zln07UjonxLBI
 VEMNcSmnIX0=
 =Bpfo
 -----END PGP SIGNATURE-----

Merge tag 'rxrpc-rewrite-20170106' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
afs: Implement bulk read

This pair of patches implements bulk data reading from an AFS server.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2017-01-06 21:52:20 -05:00
commit 1c966c5d26
6 changed files with 275 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

168
fs/afs/file.c
View File

@ -16,6 +16,7 @@
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/gfp.h>
#include <linux/task_io_accounting_ops.h>
#include "internal.h"
static int afs_readpage(struct file *file, struct page *page);
@ -101,6 +102,21 @@ int afs_release(struct inode *inode, struct file *file)
return 0;
}
/*
* Dispose of a ref to a read record.
*/
void afs_put_read(struct afs_read *req)
{
int i;
if (atomic_dec_and_test(&req->usage)) {
for (i = 0; i < req->nr_pages; i++)
if (req->pages[i])
put_page(req->pages[i]);
kfree(req);
}
}
#ifdef CONFIG_AFS_FSCACHE
/*
* deal with notification that a page was read from the cache
@ -126,9 +142,8 @@ int afs_page_filler(void *data, struct page *page)
{
struct inode *inode = page->mapping->host;
struct afs_vnode *vnode = AFS_FS_I(inode);
struct afs_read *req;
struct key *key = data;
size_t len;
off_t offset;
int ret;
_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
@ -164,12 +179,23 @@ int afs_page_filler(void *data, struct page *page)
_debug("cache said ENOBUFS");
default:
go_on:
offset = page->index << PAGE_SHIFT;
len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
GFP_KERNEL);
if (!req)
goto enomem;
atomic_set(&req->usage, 1);
req->pos = (loff_t)page->index << PAGE_SHIFT;
req->len = min_t(size_t, i_size_read(inode) - req->pos,
PAGE_SIZE);
req->nr_pages = 1;
req->pages[0] = page;
get_page(page);
/* read the contents of the file from the server into the
* page */
ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
ret = afs_vnode_fetch_data(vnode, key, req);
afs_put_read(req);
if (ret < 0) {
if (ret == -ENOENT) {
_debug("got NOENT from server"
@ -201,6 +227,8 @@ int afs_page_filler(void *data, struct page *page)
_leave(" = 0");
return 0;
enomem:
ret = -ENOMEM;
error:
SetPageError(page);
unlock_page(page);
@ -234,6 +262,129 @@ static int afs_readpage(struct file *file, struct page *page)
return ret;
}
/*
* Make pages available as they're filled.
*/
static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req)
{
struct afs_vnode *vnode = call->reply;
struct page *page = req->pages[req->index];
req->pages[req->index] = NULL;
SetPageUptodate(page);
/* send the page to the cache */
#ifdef CONFIG_AFS_FSCACHE
if (PageFsCache(page) &&
fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {
fscache_uncache_page(vnode->cache, page);
BUG_ON(PageFsCache(page));
}
#endif
unlock_page(page);
put_page(page);
}
/*
* Read a contiguous set of pages.
*/
static int afs_readpages_one(struct file *file, struct address_space *mapping,
struct list_head *pages)
{
struct afs_vnode *vnode = AFS_FS_I(mapping->host);
struct afs_read *req;
struct list_head *p;
struct page *first, *page;
struct key *key = file->private_data;
pgoff_t index;
int ret, n, i;
/* Count the number of contiguous pages at the front of the list. Note
* that the list goes prev-wards rather than next-wards.
*/
first = list_entry(pages->prev, struct page, lru);
index = first->index + 1;
n = 1;
for (p = first->lru.prev; p != pages; p = p->prev) {
page = list_entry(p, struct page, lru);
if (page->index != index)
break;
index++;
n++;
}
req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n,
GFP_NOFS);
if (!req)
return -ENOMEM;
atomic_set(&req->usage, 1);
req->page_done = afs_readpages_page_done;
req->pos = first->index;
req->pos <<= PAGE_SHIFT;
/* Transfer the pages to the request. We add them in until one fails
* to add to the LRU and then we stop (as that'll make a hole in the
* contiguous run.
*
* Note that it's possible for the file size to change whilst we're
* doing this, but we rely on the server returning less than we asked
* for if the file shrank. We also rely on this to deal with a partial
* page at the end of the file.
*/
do {
page = list_entry(pages->prev, struct page, lru);
list_del(&page->lru);
index = page->index;
if (add_to_page_cache_lru(page, mapping, index,
readahead_gfp_mask(mapping))) {
#ifdef CONFIG_AFS_FSCACHE
fscache_uncache_page(vnode->cache, page);
#endif
put_page(page);
break;
}
req->pages[req->nr_pages++] = page;
req->len += PAGE_SIZE;
} while (req->nr_pages < n);
if (req->nr_pages == 0) {
kfree(req);
return 0;
}
ret = afs_vnode_fetch_data(vnode, key, req);
if (ret < 0)
goto error;
task_io_account_read(PAGE_SIZE * req->nr_pages);
afs_put_read(req);
return 0;
error:
if (ret == -ENOENT) {
_debug("got NOENT from server"
" - marking file deleted and stale");
set_bit(AFS_VNODE_DELETED, &vnode->flags);
ret = -ESTALE;
}
for (i = 0; i < req->nr_pages; i++) {
page = req->pages[i];
if (page) {
#ifdef CONFIG_AFS_FSCACHE
fscache_uncache_page(vnode->cache, page);
#endif
SetPageError(page);
unlock_page(page);
}
}
afs_put_read(req);
return ret;
}
/*
* read a set of pages
*/
@ -287,8 +438,11 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
return ret;
}
/* load the missing pages from the network */
ret = read_cache_pages(mapping, pages, afs_page_filler, key);
while (!list_empty(pages)) {
ret = afs_readpages_one(file, mapping, pages);
if (ret < 0)
break;
}
_leave(" = %d [netting]", ret);
return ret;

117
fs/afs/fsclient.c
View File

@ -309,15 +309,19 @@ int afs_fs_fetch_file_status(struct afs_server *server,
static int afs_deliver_fs_fetch_data(struct afs_call *call)
{
struct afs_vnode *vnode = call->reply;
struct afs_read *req = call->reply3;
const __be32 *bp;
struct page *page;
unsigned int size;
void *buffer;
int ret;
_enter("{%u}", call->unmarshall);
_enter("{%u,%zu/%u;%u/%llu}",
call->unmarshall, call->offset, call->count,
req->remain, req->actual_len);
switch (call->unmarshall) {
case 0:
req->actual_len = 0;
call->offset = 0;
call->unmarshall++;
if (call->operation_ID != FSFETCHDATA64) {
@ -334,10 +338,8 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
if (ret < 0)
return ret;
call->count = ntohl(call->tmp);
_debug("DATA length MSW: %u", call->count);
if (call->count > 0)
return -EBADMSG;
req->actual_len = ntohl(call->tmp);
req->actual_len <<= 32;
call->offset = 0;
call->unmarshall++;
@ -349,26 +351,52 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
if (ret < 0)
return ret;
call->count = ntohl(call->tmp);
_debug("DATA length: %u", call->count);
if (call->count > PAGE_SIZE)
req->actual_len |= ntohl(call->tmp);
_debug("DATA length: %llu", req->actual_len);
/* Check that the server didn't want to send us extra. We
* might want to just discard instead, but that requires
* cooperation from AF_RXRPC.
*/
if (req->actual_len > req->len)
return -EBADMSG;
call->offset = 0;
req->remain = req->actual_len;
call->offset = req->pos & (PAGE_SIZE - 1);
req->index = 0;
if (req->actual_len == 0)
goto no_more_data;
call->unmarshall++;
begin_page:
if (req->remain > PAGE_SIZE - call->offset)
size = PAGE_SIZE - call->offset;
else
size = req->remain;
call->count = call->offset + size;
ASSERTCMP(call->count, <=, PAGE_SIZE);
req->remain -= size;
/* extract the returned data */
case 3:
_debug("extract data");
if (call->count > 0) {
page = call->reply3;
buffer = kmap(page);
ret = afs_extract_data(call, buffer,
call->count, true);
kunmap(page);
if (ret < 0)
return ret;
_debug("extract data %u/%llu %zu/%u",
req->remain, req->actual_len, call->offset, call->count);
buffer = kmap(req->pages[req->index]);
ret = afs_extract_data(call, buffer, call->count, true);
kunmap(req->pages[req->index]);
if (ret < 0)
return ret;
if (call->offset == PAGE_SIZE) {
if (req->page_done)
req->page_done(call, req);
if (req->remain > 0) {
req->index++;
call->offset = 0;
goto begin_page;
}
}
no_more_data:
call->offset = 0;
call->unmarshall++;
@ -393,17 +421,25 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
}
if (call->count < PAGE_SIZE) {
_debug("clear");
page = call->reply3;
buffer = kmap(page);
buffer = kmap(req->pages[req->index]);
memset(buffer + call->count, 0, PAGE_SIZE - call->count);
kunmap(page);
kunmap(req->pages[req->index]);
if (req->page_done)
req->page_done(call, req);
}
_leave(" = 0 [done]");
return 0;
}
static void afs_fetch_data_destructor(struct afs_call *call)
{
struct afs_read *req = call->reply3;
afs_put_read(req);
afs_flat_call_destructor(call);
}
/*
* FS.FetchData operation type
*/
@ -411,14 +447,14 @@ static const struct afs_call_type afs_RXFSFetchData = {
.name = "FS.FetchData",
.deliver = afs_deliver_fs_fetch_data,
.abort_to_error = afs_abort_to_error,
.destructor = afs_flat_call_destructor,
.destructor = afs_fetch_data_destructor,
};
static const struct afs_call_type afs_RXFSFetchData64 = {
.name = "FS.FetchData64",
.deliver = afs_deliver_fs_fetch_data,
.abort_to_error = afs_abort_to_error,
.destructor = afs_flat_call_destructor,
.destructor = afs_fetch_data_destructor,
};
/*
@ -427,8 +463,7 @@ static const struct afs_call_type afs_RXFSFetchData64 = {
static int afs_fs_fetch_data64(struct afs_server *server,
struct key *key,
struct afs_vnode *vnode,
off_t offset, size_t length,
struct page *buffer,
struct afs_read *req,
const struct afs_wait_mode *wait_mode)
{
struct afs_call *call;
@ -436,8 +471,6 @@ static int afs_fs_fetch_data64(struct afs_server *server,
_enter("");
ASSERTCMP(length, <, ULONG_MAX);
call = afs_alloc_flat_call(&afs_RXFSFetchData64, 32, (21 + 3 + 6) * 4);
if (!call)
return -ENOMEM;
@ -445,7 +478,7 @@ static int afs_fs_fetch_data64(struct afs_server *server,
call->key = key;
call->reply = vnode;
call->reply2 = NULL; /* volsync */
call->reply3 = buffer;
call->reply3 = req;
call->service_id = FS_SERVICE;
call->port = htons(AFS_FS_PORT);
call->operation_ID = FSFETCHDATA64;
@ -456,11 +489,12 @@ static int afs_fs_fetch_data64(struct afs_server *server,
bp[1] = htonl(vnode->fid.vid);
bp[2] = htonl(vnode->fid.vnode);
bp[3] = htonl(vnode->fid.unique);
bp[4] = htonl(upper_32_bits(offset));
bp[5] = htonl((u32) offset);
bp[4] = htonl(upper_32_bits(req->pos));
bp[5] = htonl(lower_32_bits(req->pos));
bp[6] = 0;
bp[7] = htonl((u32) length);
bp[7] = htonl(lower_32_bits(req->len));
atomic_inc(&req->usage);
return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
}
@ -470,16 +504,16 @@ static int afs_fs_fetch_data64(struct afs_server *server,
int afs_fs_fetch_data(struct afs_server *server,
struct key *key,
struct afs_vnode *vnode,
off_t offset, size_t length,
struct page *buffer,
struct afs_read *req,
const struct afs_wait_mode *wait_mode)
{
struct afs_call *call;
__be32 *bp;
if (upper_32_bits(offset) || upper_32_bits(offset + length))
return afs_fs_fetch_data64(server, key, vnode, offset, length,
buffer, wait_mode);
if (upper_32_bits(req->pos) ||
upper_32_bits(req->len) ||
upper_32_bits(req->pos + req->len))
return afs_fs_fetch_data64(server, key, vnode, req, wait_mode);
_enter("");
@ -490,7 +524,7 @@ int afs_fs_fetch_data(struct afs_server *server,
call->key = key;
call->reply = vnode;
call->reply2 = NULL; /* volsync */
call->reply3 = buffer;
call->reply3 = req;
call->service_id = FS_SERVICE;
call->port = htons(AFS_FS_PORT);
call->operation_ID = FSFETCHDATA;
@ -501,9 +535,10 @@ int afs_fs_fetch_data(struct afs_server *server,
bp[1] = htonl(vnode->fid.vid);
bp[2] = htonl(vnode->fid.vnode);
bp[3] = htonl(vnode->fid.unique);
bp[4] = htonl(offset);
bp[5] = htonl(length);
bp[4] = htonl(lower_32_bits(req->pos));
bp[5] = htonl(lower_32_bits(req->len));
atomic_inc(&req->usage);
return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
}

21
fs/afs/internal.h
View File

@ -133,6 +133,22 @@ struct afs_call_type {
void (*destructor)(struct afs_call *call);
};
/*
* Record of an outstanding read operation on a vnode.
*/
struct afs_read {
loff_t pos; /* Where to start reading */
loff_t len; /* How much to read */
loff_t actual_len; /* How much we're actually getting */
atomic_t usage;
unsigned int remain; /* Amount remaining */
unsigned int index; /* Which page we're reading into */
unsigned int pg_offset; /* Offset in page we're at */
unsigned int nr_pages;
void (*page_done)(struct afs_call *, struct afs_read *);
struct page *pages[];
};
/*
* record of an outstanding writeback on a vnode
*/
@ -494,6 +510,7 @@ extern const struct file_operations afs_file_operations;
extern int afs_open(struct inode *, struct file *);
extern int afs_release(struct inode *, struct file *);
extern int afs_page_filler(void *, struct page *);
extern void afs_put_read(struct afs_read *);
/*
* flock.c
@ -513,7 +530,7 @@ extern int afs_fs_fetch_file_status(struct afs_server *, struct key *,
extern int afs_fs_give_up_callbacks(struct afs_server *,
const struct afs_wait_mode *);
extern int afs_fs_fetch_data(struct afs_server *, struct key *,
struct afs_vnode *, off_t, size_t, struct page *,
struct afs_vnode *, struct afs_read *,
const struct afs_wait_mode *);
extern int afs_fs_create(struct afs_server *, struct key *,
struct afs_vnode *, const char *, umode_t,
@ -699,7 +716,7 @@ extern void afs_vnode_finalise_status_update(struct afs_vnode *,
extern int afs_vnode_fetch_status(struct afs_vnode *, struct afs_vnode *,
struct key *);
extern int afs_vnode_fetch_data(struct afs_vnode *, struct key *,
off_t, size_t, struct page *);
struct afs_read *);
extern int afs_vnode_create(struct afs_vnode *, struct key *, const char *,
umode_t, struct afs_fid *, struct afs_file_status *,
struct afs_callback *, struct afs_server **);

6
fs/afs/vnode.c
View File

@ -393,7 +393,7 @@ no_server:
* - TODO implement caching
*/
int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
off_t offset, size_t length, struct page *page)
struct afs_read *desc)
{
struct afs_server *server;
int ret;
@ -420,8 +420,8 @@ int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
ret = afs_fs_fetch_data(server, key, vnode, offset, length,
page, &afs_sync_call);
ret = afs_fs_fetch_data(server, key, vnode, desc,
&afs_sync_call);
} while (!afs_volume_release_fileserver(vnode, server, ret));

1
fs/afs/volume.c
View File

@ -106,6 +106,7 @@ struct afs_volume *afs_volume_lookup(struct afs_mount_params *params)
volume->cell = params->cell;
volume->vid = vlocation->vldb.vid[params->type];
volume->bdi.ra_pages = VM_MAX_READAHEAD*1024/PAGE_SIZE;
ret = bdi_setup_and_register(&volume->bdi, "afs");
if (ret)
goto error_bdi;

19
fs/afs/write.c
View File

@ -86,19 +86,30 @@ void afs_put_writeback(struct afs_writeback *wb)
static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
loff_t pos, struct page *page)
{
struct afs_read *req;
loff_t i_size;
int ret;
int len;
_enter(",,%llu", (unsigned long long)pos);
req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
GFP_KERNEL);
if (!req)
return -ENOMEM;
atomic_set(&req->usage, 1);
req->pos = pos;
req->nr_pages = 1;
req->pages[0] = page;
i_size = i_size_read(&vnode->vfs_inode);
if (pos + PAGE_SIZE > i_size)
len = i_size - pos;
req->len = i_size - pos;
else
len = PAGE_SIZE;
req->len = PAGE_SIZE;
ret = afs_vnode_fetch_data(vnode, key, pos, len, page);
ret = afs_vnode_fetch_data(vnode, key, req);
afs_put_read(req);
if (ret < 0) {
if (ret == -ENOENT) {
_debug("got NOENT from server"