If we request reading or writing on a file that needs to be reopened, it causes the deadlock: we are already holding rw semaphore for reading and then we try to acquire it for writing in cifs_relock_file. Fix this by acquiring the semaphore for reading in cifs_relock_file due to we don't make any changes in locks and don't need a write access.
Signed-off-by: Pavel Shilovsky <[email protected]> --- fs/cifs/file.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index b149ae4..be24f09 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -561,11 +561,10 @@ cifs_relock_file(struct cifsFileInfo *cfile) struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); int rc = 0; - /* we are going to update can_cache_brlcks here - need a write access */ - down_write(&cinode->lock_sem); + down_read(&cinode->lock_sem); if (cinode->can_cache_brlcks) { - /* can cache locks - no need to push them */ - up_write(&cinode->lock_sem); + /* can cache locks - no need to relock */ + up_read(&cinode->lock_sem); return rc; } @@ -576,7 +575,7 @@ cifs_relock_file(struct cifsFileInfo *cfile) else rc = tcon->ses->server->ops->push_mand_locks(cfile); - up_write(&cinode->lock_sem); + up_read(&cinode->lock_sem); return rc; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
