[PATCH 5.10 05/15] fuse: always revalidate if exclusive create

Greg Kroah-Hartman
2022-12-15T18:11:53Z

From: Miklos Szeredi <mszeredi@redhat.com>

commit df8629af293493757beccac2d3168fe5a315636e upstream.

Failure to do so may result in EEXIST even if the file only exists in the
cache and not in the filesystem.

The atomic nature of O_EXCL mandates that the cached state should be
ignored and existence verified anew.

Reported-by: Ken Schalk <kschalk@nvidia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Wu Bo <bo.wu@vivo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/fuse/dir.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -205,7 +205,7 @@ static int fuse_dentry_revalidate(struct
if (inode && fuse_is_bad(inode))
goto invalid;
else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
- (flags & LOOKUP_REVAL)) {
+ (flags & (LOOKUP_EXCL | LOOKUP_REVAL))) {
struct fuse_entry_out outarg;
FUSE_ARGS(args);
struct fuse_forget_link *forget;