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 <[email protected]> --- 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
