On Thu, 2026-04-16 at 21:24 +0200, Amir Goldstein wrote: > On Thu, Apr 16, 2026 at 7:35 PM Jeff Layton <[email protected]> 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 <[email protected]> > > --- > > include/linux/fsnotify.h | 8 ++++++-- > > include/linux/fsnotify_backend.h | 20 ++++++++++++++++++++ > > 2 files changed, 26 insertions(+), 2 deletions(-) > > It is strange to me that the NFS protocol needs to report the overwritten > node in the same event of the rename, but oh well, fine by me. >
Yeah, it's not very useful, but the protocol requires it. Unfortunately RFC5661 was written before anyone had made a real implementation of directory delegations. If we were rewriting it today, we'd probably make that info optional. > Feel free to add: > Reviewed-by: Amir Goldstein <[email protected]> > > Thanks, Amir! > > > > 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 > > -- Jeff Layton <[email protected]>
