This is a note to let you know that I've just added the patch titled
afs: Fix file locking on R/O volumes to operate in local mode
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
afs-fix-file-locking-on-r-o-volumes-to-operate-in-lo.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5c3483cc58b047af7e6fae4ce8bf2c9b25206ea1
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Wed Nov 1 22:03:28 2023 +0000
afs: Fix file locking on R/O volumes to operate in local mode
[ Upstream commit b590eb41be766c5a63acc7e8896a042f7a4e8293 ]
AFS doesn't really do locking on R/O volumes as fileservers don't maintain
state with each other and thus a lock on a R/O volume file on one
fileserver will not be be visible to someone looking at the same file on
another fileserver.
Further, the server may return an error if you try it.
Fix this by doing what other AFS clients do and handle filelocking on R/O
volume files entirely within the client and don't touch the server.
Fixes: 6c6c1d63c243 ("afs: Provide mount-time configurable byte-range file locking emulation")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/afs/super.c b/fs/afs/super.c
index eb04dcc543289..554119068ea44 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -391,6 +391,8 @@ static int afs_validate_fc(struct fs_context *fc)
return PTR_ERR(volume);
ctx->volume = volume;
+ if (volume->type != AFSVL_RWVOL)
+ ctx->flock_mode = afs_flock_mode_local;
}
return 0;
