From d24a18cb51bfea3c5179e3966738de884dc2bde3 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 e38bb1e7a4d2..1b62a99b3673 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;