Patch "fsnotify: optimize the case of no marks of any type" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    fsnotify: optimize the case of no marks of any type

to the 5.10-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-optimize-the-case-of-no-marks-of-any-type.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7d7b19fa04780d3f60cb78e1e255e3e3f03ccb83
Author: Amir Goldstein <amir73il@xxxxxxxxx>
Date:   Tue Aug 10 18:12:20 2021 +0300

    fsnotify: optimize the case of no marks of any type
    
    [ Upstream commit e43de7f0862b8598cd1ef440e3b4701cd107ea40 ]
    
    Add a simple check in the inline helpers to avoid calling fsnotify()
    and __fsnotify_parent() in case there are no marks of any type
    (inode/sb/mount) for an inode's sb, so there can be no objects
    of any type interested in the event.
    
    Link: https://lore.kernel.org/r/20210810151220.285179-5-amir73il@xxxxxxxxx
    Reviewed-by: Matthew Bobrowski <repnop@xxxxxxxxxx>
    Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
    Signed-off-by: Jan Kara <jack@xxxxxxx>
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 79add91eaa04e..a9477c14fad5c 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -30,6 +30,9 @@ static inline void fsnotify_name(struct inode *dir, __u32 mask,
 				 struct inode *child,
 				 const struct qstr *name, u32 cookie)
 {
+	if (atomic_long_read(&dir->i_sb->s_fsnotify_connectors) == 0)
+		return;
+
 	fsnotify(mask, child, FSNOTIFY_EVENT_INODE, dir, name, NULL, cookie);
 }
 
@@ -41,6 +44,9 @@ static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry,
 
 static inline void fsnotify_inode(struct inode *inode, __u32 mask)
 {
+	if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0)
+		return;
+
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
 
@@ -53,6 +59,9 @@ static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
 {
 	struct inode *inode = d_inode(dentry);
 
+	if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0)
+		return 0;
+
 	if (S_ISDIR(inode->i_mode)) {
 		mask |= FS_ISDIR;