2021-10-15 01:18:56

by Gabriel Krisman Bertazi

[permalink] [raw]
Subject: [PATCH v7 13/28] fanotify: Allow file handle encoding for unhashed events

Allow passing a NULL hash to fanotify_encode_fh and avoid calculating
the hash if not needed.

Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Amir Goldstein <[email protected]>
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
---
fs/notify/fanotify/fanotify.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 397ee623ff1e..ec84fee7ad01 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -403,8 +403,12 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
fh->type = type;
fh->len = fh_len;

- /* Mix fh into event merge key */
- *hash ^= fanotify_hash_fh(fh);
+ /*
+ * Mix fh into event merge key. Hash might be NULL in case of
+ * unhashed FID events (i.e. FAN_FS_ERROR).
+ */
+ if (hash)
+ *hash ^= fanotify_hash_fh(fh);

return FANOTIFY_FH_HDR_LEN + fh_len;

--
2.33.0