Re: [PATCH v2 07/28] fsnotify: add FSNOTIFY_EVENT_RENAME data type

Jan Kara
2026-04-17T11:57:00Z

On Thu 16-04-26 10:35:08, Jeff Layton wrote:
> Add a new fsnotify_rename_data struct and FSNOTIFY_EVENT_RENAME data
> type that carries both the moved dentry and the inode that was
> overwritten by the rename (if any).
>
> Update fsnotify_data_inode(), fsnotify_data_dentry(), and
> fsnotify_data_sb() to handle the new type, and add a new
> fsnotify_data_rename_target() helper for extracting the overwritten
> target inode.
>
> Update fsnotify_move() to use the new data type for FS_RENAME and
> FS_MOVED_TO events, passing the overwritten target inode through the
> event data. FS_MOVED_FROM is unchanged since the source directory
> doesn't need overwrite information.
>
> This is done so that fsnotify consumers like nfsd can atomically
> observe the overwritten file when a rename replaces an existing entry,
> without needing a separate FS_DELETE event.
>
> Assisted-by: Claude (Anthropic Claude Code)
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> include/linux/fsnotify.h | 8 ++++++--
> include/linux/fsnotify_backend.h | 20 ++++++++++++++++++++
> 2 files changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
> index 079c18bcdbde..bda798bc67bc 100644
> --- a/include/linux/fsnotify.h
> +++ b/include/linux/fsnotify.h
> @@ -257,6 +257,10 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
> __u32 new_dir_mask = FS_MOVED_TO;
> __u32 rename_mask = FS_RENAME;
> const struct qstr *new_name = &moved->d_name;
> + struct fsnotify_rename_data rd = {
> + .moved = moved,
> + .target = target,
> + };
>
> if (isdir) {
> old_dir_mask |= FS_ISDIR;
> @@ -265,12 +269,12 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
> }
>
> /* Event with information about both old and new parent+name */
> - fsnotify_name(rename_mask, moved, FSNOTIFY_EVENT_DENTRY,
> + fsnotify_name(rename_mask, &rd, FSNOTIFY_EVENT_RENAME,
> old_dir, old_name, 0);
>
> fsnotify_name(old_dir_mask, source, FSNOTIFY_EVENT_INODE,
> old_dir, old_name, fs_cookie);
> - fsnotify_name(new_dir_mask, source, FSNOTIFY_EVENT_INODE,
> + fsnotify_name(new_dir_mask, &rd, FSNOTIFY_EVENT_RENAME,
> new_dir, new_name, fs_cookie);
>
> if (target)
> diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
> index 66e185bd1b1b..f8c8fb7f34ae 100644
> --- a/include/linux/fsnotify_backend.h
> +++ b/include/linux/fsnotify_backend.h
> @@ -311,6 +311,7 @@ enum fsnotify_data_type {
> FSNOTIFY_EVENT_DENTRY,
> FSNOTIFY_EVENT_MNT,
> FSNOTIFY_EVENT_ERROR,
> + FSNOTIFY_EVENT_RENAME,
> };
>
> struct fs_error_report {
> @@ -335,6 +336,11 @@ struct fsnotify_mnt {
> u64 mnt_id;
> };
>
> +struct fsnotify_rename_data {
> + struct dentry *moved; /* the dentry that was renamed */
> + struct inode *target; /* inode overwritten by rename, or NULL */
> +};
> +
> static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
> {
> switch (data_type) {
> @@ -348,6 +354,8 @@ static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
> return d_inode(file_range_path(data)->dentry);
> case FSNOTIFY_EVENT_ERROR:
> return ((struct fs_error_report *)data)->inode;
> + case FSNOTIFY_EVENT_RENAME:
> + return d_inode(((const struct fsnotify_rename_data *)data)->moved);
> default:
> return NULL;
> }
> @@ -363,6 +371,8 @@ static inline struct dentry *fsnotify_data_dentry(const void *data, int data_typ
> return ((const struct path *)data)->dentry;
> case FSNOTIFY_EVENT_FILE_RANGE:
> return file_range_path(data)->dentry;
> + case FSNOTIFY_EVENT_RENAME:
> + return ((struct fsnotify_rename_data *)data)->moved;
> default:
> return NULL;
> }
> @@ -395,6 +405,8 @@ static inline struct super_block *fsnotify_data_sb(const void *data,
> return file_range_path(data)->dentry->d_sb;
> case FSNOTIFY_EVENT_ERROR:
> return ((struct fs_error_report *) data)->sb;
> + case FSNOTIFY_EVENT_RENAME:
> + return ((const struct fsnotify_rename_data *)data)->moved->d_sb;
> default:
> return NULL;
> }
> @@ -430,6 +442,14 @@ static inline struct fs_error_report *fsnotify_data_error_report(
> }
> }
>
> +static inline struct inode *fsnotify_data_rename_target(const void *data,
> + int data_type)
> +{
> + if (data_type == FSNOTIFY_EVENT_RENAME)
> + return ((const struct fsnotify_rename_data *)data)->target;
> + return NULL;
> +}
> +
> static inline const struct file_range *fsnotify_data_file_range(
> const void *data,
> int data_type)
>
> --
> 2.53.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR