This is a note to let you know that I've just added the patch titled
fsnotify: clarify contract for create event hooks
to the 5.15-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:
fsnotify-clarify-contract-for-create-event-hooks.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d3593808aa0a1a9916ef1410fa57cd3ad92fac73
Author: Amir Goldstein <amir73il@xxxxxxxxx>
Date: Mon Oct 25 16:27:18 2021 -0300
fsnotify: clarify contract for create event hooks
[ Upstream commit dabe729dddca550446e9cc118c96d1f91703345b ]
Clarify argument names and contract for fsnotify_create() and
fsnotify_mkdir() to reflect the anomaly of kernfs, which leaves dentries
negavite after mkdir/create.
Remove the WARN_ON(!inode) in audit code that were added by the Fixes
commit under the wrong assumption that dentries cannot be negative after
mkdir/create.
Fixes: aa93bdc5500c ("fsnotify: use helpers to access data by data_type")
Link: https://lore.kernel.org/linux-fsdevel/87mtp5yz0q.fsf@xxxxxxxxxxxxx/
Link: https://lore.kernel.org/r/20211025192746.66445-4-krisman@xxxxxxxxxxxxx
Reviewed-by: Jan Kara <jack@xxxxxxx>
Reported-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 70e6b147a76ad..a327a95fa68f1 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -192,16 +192,22 @@ static inline void fsnotify_inoderemove(struct inode *inode)
/*
* fsnotify_create - 'name' was linked in
+ *
+ * Caller must make sure that dentry->d_name is stable.
+ * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate
+ * ->d_inode later
*/
-static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
+static inline void fsnotify_create(struct inode *dir, struct dentry *dentry)
{
- audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
+ audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE);
- fsnotify_dirent(inode, dentry, FS_CREATE);
+ fsnotify_dirent(dir, dentry, FS_CREATE);
}
/*
* fsnotify_link - new hardlink in 'inode' directory
+ *
+ * Caller must make sure that new_dentry->d_name is stable.
* Note: We have to pass also the linked inode ptr as some filesystems leave
* new_dentry->d_inode NULL and instantiate inode pointer later
*/
@@ -266,12 +272,16 @@ static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry)
/*
* fsnotify_mkdir - directory 'name' was created
+ *
+ * Caller must make sure that dentry->d_name is stable.
+ * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate
+ * ->d_inode later
*/
-static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
+static inline void fsnotify_mkdir(struct inode *dir, struct dentry *dentry)
{
- audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
+ audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE);
- fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR);
+ fsnotify_dirent(dir, dentry, FS_CREATE | FS_ISDIR);
}
/*
diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
index c428312938e95..7a506b65e8630 100644
--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -161,8 +161,7 @@ static int audit_mark_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark);
- if (WARN_ON_ONCE(inode_mark->group != audit_fsnotify_group) ||
- WARN_ON_ONCE(!inode))
+ if (WARN_ON_ONCE(inode_mark->group != audit_fsnotify_group))
return 0;
if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) {
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index edbeffee64b8e..fd7b30a2d9a4b 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -472,8 +472,7 @@ static int audit_watch_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
parent = container_of(inode_mark, struct audit_parent, mark);
- if (WARN_ON_ONCE(inode_mark->group != audit_watch_group) ||
- WARN_ON_ONCE(!inode))
+ if (WARN_ON_ONCE(inode_mark->group != audit_watch_group))
return 0;
if (mask & (FS_CREATE|FS_MOVED_TO) && inode)
