ceph: convert ceph_readpages to ceph_readahead

Convert ceph_readpages to ceph_readahead and make it use
netfs_readahead. With this we can rip out a lot of the old
readpage/readpages infrastructure.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Jeff Layton 2020-07-09 14:43:23 -04:00 committed by Ilya Dryomov
parent d801327d95
commit 4987005600

View File

@ -305,6 +305,16 @@ static void ceph_init_rreq(struct netfs_read_request *rreq, struct file *file)
{
}
static void ceph_readahead_cleanup(struct address_space *mapping, void *priv)
{
struct inode *inode = mapping->host;
struct ceph_inode_info *ci = ceph_inode(inode);
int got = (uintptr_t)priv;
if (got)
ceph_put_cap_refs(ci, got);
}
const struct netfs_read_request_ops ceph_netfs_read_ops = {
.init_rreq = ceph_init_rreq,
.is_cache_enabled = ceph_is_cache_enabled,
@ -313,6 +323,7 @@ const struct netfs_read_request_ops ceph_netfs_read_ops = {
.expand_readahead = ceph_netfs_expand_readahead,
.clamp_length = ceph_netfs_clamp_length,
.check_write_begin = ceph_netfs_check_write_begin,
.cleanup = ceph_readahead_cleanup,
};
/* read a single page, without unlocking it. */
@ -345,214 +356,35 @@ static int ceph_readpage(struct file *file, struct page *page)
return netfs_readpage(file, page, &ceph_netfs_read_ops, NULL);
}
/*
* Finish an async read(ahead) op.
*/
static void finish_read(struct ceph_osd_request *req)
static void ceph_readahead(struct readahead_control *ractl)
{
struct inode *inode = req->r_inode;
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_osd_data *osd_data;
int rc = req->r_result <= 0 ? req->r_result : 0;
int bytes = req->r_result >= 0 ? req->r_result : 0;
int num_pages;
int i;
dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
if (rc == -EBLOCKLISTED)
ceph_inode_to_client(inode)->blocklisted = true;
/* unlock all pages, zeroing any data we didn't read */
osd_data = osd_req_op_extent_osd_data(req, 0);
BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
num_pages = calc_pages_for((u64)osd_data->alignment,
(u64)osd_data->length);
for (i = 0; i < num_pages; i++) {
struct page *page = osd_data->pages[i];
if (rc < 0 && rc != -ENOENT)
goto unlock;
if (bytes < (int)PAGE_SIZE) {
/* zero (remainder of) page */
int s = bytes < 0 ? 0 : bytes;
zero_user_segment(page, s, PAGE_SIZE);
}
dout("finish_read %p uptodate %p idx %lu\n", inode, page,
page->index);
flush_dcache_page(page);
SetPageUptodate(page);
unlock:
unlock_page(page);
put_page(page);
bytes -= PAGE_SIZE;
}
ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
req->r_end_latency, rc);
kfree(osd_data->pages);
}
/*
* start an async read(ahead) operation. return nr_pages we submitted
* a read for on success, or negative error code.
*/
static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
struct list_head *page_list, int max)
{
struct ceph_osd_client *osdc =
&ceph_inode_to_client(inode)->client->osdc;
struct ceph_inode_info *ci = ceph_inode(inode);
struct page *page = lru_to_page(page_list);
struct ceph_vino vino;
struct ceph_osd_request *req;
u64 off;
u64 len;
int i;
struct page **pages;
pgoff_t next_index;
int nr_pages = 0;
struct inode *inode = file_inode(ractl->file);
struct ceph_file_info *fi = ractl->file->private_data;
struct ceph_rw_context *rw_ctx;
int got = 0;
int ret = 0;
if (!rw_ctx) {
/* caller of readpages does not hold buffer and read caps
* (fadvise, madvise and readahead cases) */
int want = CEPH_CAP_FILE_CACHE;
ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want,
true, &got);
if (ret < 0) {
dout("start_read %p, error getting cap\n", inode);
} else if (!(got & want)) {
dout("start_read %p, no cache cap\n", inode);
ret = 0;
}
if (ret <= 0) {
if (got)
ceph_put_cap_refs(ci, got);
while (!list_empty(page_list)) {
page = lru_to_page(page_list);
list_del(&page->lru);
put_page(page);
}
return ret;
}
}
off = (u64) page_offset(page);
/* count pages */
next_index = page->index;
list_for_each_entry_reverse(page, page_list, lru) {
if (page->index != next_index)
break;
nr_pages++;
next_index++;
if (max && nr_pages == max)
break;
}
len = nr_pages << PAGE_SHIFT;
dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
off, len);
vino = ceph_vino(inode);
req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
0, 1, CEPH_OSD_OP_READ,
CEPH_OSD_FLAG_READ, NULL,
ci->i_truncate_seq, ci->i_truncate_size,
false);
if (IS_ERR(req)) {
ret = PTR_ERR(req);
goto out;
}
/* build page vector */
nr_pages = calc_pages_for(0, len);
pages = kmalloc_array(nr_pages, sizeof(*pages), GFP_KERNEL);
if (!pages) {
ret = -ENOMEM;
goto out_put;
}
for (i = 0; i < nr_pages; ++i) {
page = list_entry(page_list->prev, struct page, lru);
BUG_ON(PageLocked(page));
list_del(&page->lru);
dout("start_read %p adding %p idx %lu\n", inode, page,
page->index);
if (add_to_page_cache_lru(page, &inode->i_data, page->index,
GFP_KERNEL)) {
put_page(page);
dout("start_read %p add_to_page_cache failed %p\n",
inode, page);
nr_pages = i;
if (nr_pages > 0) {
len = nr_pages << PAGE_SHIFT;
osd_req_op_extent_update(req, 0, len);
break;
}
goto out_pages;
}
pages[i] = page;
}
osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
req->r_callback = finish_read;
req->r_inode = inode;
dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
ret = ceph_osdc_start_request(osdc, req, false);
if (ret < 0)
goto out_pages;
ceph_osdc_put_request(req);
/* After adding locked pages to page cache, the inode holds cache cap.
* So we can drop our cap refs. */
if (got)
ceph_put_cap_refs(ci, got);
return nr_pages;
out_pages:
for (i = 0; i < nr_pages; ++i)
unlock_page(pages[i]);
ceph_put_page_vector(pages, nr_pages, false);
out_put:
ceph_osdc_put_request(req);
out:
if (got)
ceph_put_cap_refs(ci, got);
return ret;
}
/*
* Read multiple pages. Leave pages we don't read + unlock in page_list;
* the caller (VM) cleans them up.
*/
static int ceph_readpages(struct file *file, struct address_space *mapping,
struct list_head *page_list, unsigned nr_pages)
{
struct inode *inode = file_inode(file);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_file_info *fi = file->private_data;
struct ceph_rw_context *rw_ctx;
int rc = 0;
int max = 0;
if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
return -EINVAL;
return;
rw_ctx = ceph_find_rw_context(fi);
max = fsc->mount_options->rsize >> PAGE_SHIFT;
dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
inode, file, rw_ctx, nr_pages, max);
while (!list_empty(page_list)) {
rc = start_read(inode, rw_ctx, page_list, max);
if (rc < 0)
goto out;
if (!rw_ctx) {
/*
* readahead callers do not necessarily hold Fcb caps
* (e.g. fadvise, madvise).
*/
int want = CEPH_CAP_FILE_CACHE;
ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want, true, &got);
if (ret < 0)
dout("start_read %p, error getting cap\n", inode);
else if (!(got & want))
dout("start_read %p, no cache cap\n", inode);
if (ret <= 0)
return;
}
out:
dout("readpages %p file %p ret %d\n", inode, file, rc);
return rc;
netfs_readahead(ractl, &ceph_netfs_read_ops, (void *)(uintptr_t)got);
}
struct ceph_writeback_ctl
@ -1497,7 +1329,7 @@ static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter)
const struct address_space_operations ceph_aops = {
.readpage = ceph_readpage,
.readpages = ceph_readpages,
.readahead = ceph_readahead,
.writepage = ceph_writepage,
.writepages = ceph_writepages_start,
.write_begin = ceph_write_begin,