From b5d50c6a609da672e0606a2791102e1eed440c8b Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 1 Nov 2023 22:03:28 +0000 Subject: [PATCH] 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 Reviewed-by: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin --- fs/afs/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/afs/super.c b/fs/afs/super.c index 34c68724c98b..910e73bb5a08 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -406,6 +406,8 @@ 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;