Commit c738fbab authored by Amir Goldstein's avatar Amir Goldstein Committed by Jan Kara
Browse files

fsnotify: fold fsnotify() call into fsnotify_parent() 

All (two) callers of fsnotify_parent() also call fsnotify() to notify
the child inode. Move the second fsnotify() call into fsnotify_parent().

This will allow more flexibility in making decisions about which of the
two event falvors should be sent.

Using 'goto notify_child' in the inline helper seems a bit strange, but
it mimics the code in __fsnotify_parent() for clarity and the goto
pattern will become less strage after following patches are applied.

Link: https://lore.kernel.org/r/20200708111156.24659-2-amir73il@gmail.com


Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 71d73410

fs/notify/fsnotify.c

+18 −9
Original line number Diff line number Diff line
@@ -142,7 +142,11 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) 
	spin_unlock(&inode->i_lock);

}



/* Notify this dentry's parent about a child's events. */

/*

 * Notify this dentry's parent about a child's events with child name info

 * if parent is watching.

 * Notify also the child without name info if child inode is watching.

 */

int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,

		      int data_type)

{
@@ -151,7 +155,7 @@ int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, 
	int ret = 0;



	if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))

		return 0;

		goto notify_child;



	parent = dget_parent(dentry);

	p_inode = parent->d_inode;
@@ -161,18 +165,23 @@ int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, 
	} else if (p_inode->i_fsnotify_mask & mask & ALL_FSNOTIFY_EVENTS) {

		struct name_snapshot name;



		/* we are notifying a parent so come up with the new mask which

		 * specifies these are events which came from a child. */

		mask |= FS_EVENT_ON_CHILD;



		/*

		 * We are notifying a parent, so set a flag in mask to inform

		 * backend that event has information about a child entry.

		 */

		take_dentry_name_snapshot(&name, dentry);

		ret = fsnotify(p_inode, mask, data, data_type, &name.name, 0);

		ret = fsnotify(p_inode, mask | FS_EVENT_ON_CHILD, data,

			       data_type, &name.name, 0);

		release_dentry_name_snapshot(&name);

	}



	dput(parent);



	if (ret)

		return ret;



notify_child:

	return fsnotify(d_inode(dentry), mask, data, data_type, NULL, 0);

}

EXPORT_SYMBOL_GPL(__fsnotify_parent);

include/linux/fsnotify.h

+13 −20
Original line number Diff line number Diff line
@@ -48,44 +48,37 @@ static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry, 
static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,

				  const void *data, int data_type)

{

	struct inode *inode = d_inode(dentry);



	if (S_ISDIR(inode->i_mode))

		mask |= FS_ISDIR;



	if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))

		return 0;

		goto notify_child;



	return __fsnotify_parent(dentry, mask, data, data_type);



notify_child:

	return fsnotify(inode, mask, data, data_type, NULL, 0);

}



/*

 * Simple wrappers to consolidate calls fsnotify_parent()/fsnotify() when

 * an event is on a file/dentry.

 * Simple wrappers to consolidate calls to fsnotify_parent() when an event

 * is on a file/dentry.

 */

static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask)

{

	struct inode *inode = d_inode(dentry);



	if (S_ISDIR(inode->i_mode))

		mask |= FS_ISDIR;



	fsnotify_parent(dentry, mask, inode, FSNOTIFY_EVENT_INODE);

	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);

	fsnotify_parent(dentry, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE);

}



static inline int fsnotify_file(struct file *file, __u32 mask)

{

	const struct path *path = &file->f_path;

	struct inode *inode = file_inode(file);

	int ret;



	if (file->f_mode & FMODE_NONOTIFY)

		return 0;



	if (S_ISDIR(inode->i_mode))

		mask |= FS_ISDIR;



	ret = fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH);

	if (ret)

		return ret;



	return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);

	return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH);

}



/* Simple call site for access decisions */