qiurui/Centos-kernel-stream-10
1
0
Fork 0
mirror of https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10.git synced 2026-09-09 00:07:04 +08:00
Code Issues Packages Projects Releases Wiki Activity

netfs, afs: Fix write skipping in dir/link writepages

Browse Source 
JIRA: https://issues.redhat.com/browse/RHEL-190706

commit 9871938f99cc6cb266a77265491660e2375271f5
Author: David Howells <dhowells@redhat.com>
Date:   Tue May 12 13:34:00 2026 +0100

    netfs, afs: Fix write skipping in dir/link writepages
    
    Fix netfs_write_single() and afs_single_writepages() to better handle a
    write that would be skipped due to lock contention and WB_SYNC_NONE by
    returning 1 from netfs_write_single() if it skipped and making
    afs_single_writepages() skip also.  If a skip occurs, the inode must be
    re-marked as the VFS may have cleared the mark.
    
    This is really only theoretical for directories in netfs_write_single() as
    the only path to that is through afs_single_writepages() that takes the
    ->validate_lock around it, thereby serialising it.
    
    Fixes: 6dd80936618c ("afs: Use netfslib for directories")
    Signed-off-by: David Howells <dhowells@redhat.com>
    Link: https://patch.msgid.link/20260512123404.719402-24-dhowells@redhat.com
    cc: Marc Dionne <marc.dionne@auristor.com>
    cc: linux-afs@lists.infradead.org
    cc: linux-fsdevel@vger.kernel.org
    Signed-off-by: Christian Brauner <brauner@kernel.org>

Signed-off-by: Paulo Alcantara <paalcant@redhat.com>
This commit is contained in:
Paulo Alcantara
2026-07-20 20:28:29 -03:00
parent fb55e9ba8d
commit 8a3dd0666c
2 changed files with 16 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/afs/dir.c
+10 -1
View File
@@ -2094,7 +2094,14 @@ int afs_single_writepages(struct address_space *mapping,
/* Need to lock to prevent the folio queue and folios from being thrown
* away.
*/
down_read(&dvnode->validate_lock);
if (!down_read_trylock(&dvnode->validate_lock)) {
if (wbc->sync_mode == WB_SYNC_NONE) {
/* The VFS will have undirtied the inode. */
netfs_single_mark_inode_dirty(&dvnode->netfs.inode);
return 0;
}
down_read(&dvnode->validate_lock);
}
if (is_dir ?
test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) :
@@ -2102,6 +2109,8 @@ int afs_single_writepages(struct address_space *mapping,
iov_iter_folio_queue(&iter, ITER_SOURCE, dvnode->directory, 0, 0,
i_size_read(&dvnode->netfs.inode));
ret = netfs_writeback_single(mapping, wbc, &iter);
if (ret == 1)
ret = 0; /* Skipped write due to lock conflict. */
}
up_read(&dvnode->validate_lock);
fs/netfs/write_issue.c
+6 -1
View File
@@ -830,6 +830,9 @@ static int netfs_write_folio_single(struct netfs_io_request *wreq,
*
* Write a monolithic, non-pagecache object back to the server and/or
* the cache.
*
* Return: 0 if successful; 1 if skipped due to lock conflict and WB_SYNC_NONE;
* or a negative error code.
*/
int netfs_writeback_single(struct address_space *mapping,
struct writeback_control *wbc,
@@ -846,8 +849,10 @@ int netfs_writeback_single(struct address_space *mapping,
if (!mutex_trylock(&ictx->wb_lock)) {
if (wbc->sync_mode == WB_SYNC_NONE) {
/* The VFS will have undirtied the inode. */
netfs_single_mark_inode_dirty(&ictx->inode);
netfs_stat(&netfs_n_wb_lock_skip);
return 0;
return 1;
}
netfs_stat(&netfs_n_wb_lock_wait);
mutex_lock(&ictx->wb_lock);