On Fri, May 21, 2021 at 5:42 AM Gabriel Krisman Bertazi
<krisman@xxxxxxxxxxxxx> wrote:
>
> Expose a new type of fsnotify event for filesystems to report errors for
> userspace monitoring tools. fanotify will send this type of
> notification for FAN_ERROR events.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
>
> ---
> Changes since v1:
> - Overload FS_ERROR with FS_IN_IGNORED
> ---
> include/linux/fsnotify_backend.h | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
> index 1ce66748a2d2..bbef2df3fbc7 100644
> --- a/include/linux/fsnotify_backend.h
> +++ b/include/linux/fsnotify_backend.h
> @@ -42,6 +42,12 @@
>
> #define FS_UNMOUNT 0x00002000 /* inode on umount fs */
> #define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
> +#define FS_ERROR 0x00008000 /* Filesystem Error (fanotify) */
> +
> +/*
> + * FS_IN_IGNORED overloads FS_ERROR. It is only used internally by inotify
> + * which does not support FS_ERROR.
> + */
> #define FS_IN_IGNORED 0x00008000 /* last inotify event here */
>
> #define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */
> @@ -95,7 +101,8 @@
> #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \
> FS_EVENTS_POSS_ON_CHILD | \
> FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \
> - FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED)
> + FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \
> + FS_ERROR)
>
> /* Extra flags that may be reported with event or control handling of events */
> #define ALL_FSNOTIFY_FLAGS (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \
> @@ -248,6 +255,12 @@ enum fsnotify_data_type {
> FSNOTIFY_EVENT_NONE,
> FSNOTIFY_EVENT_PATH,
> FSNOTIFY_EVENT_INODE,
> + FSNOTIFY_EVENT_ERROR,
> +};
> +
> +struct fs_error_report {
> + int error;
> + struct inode *inode;
> };
>
> static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
Your patch may not use it, but I prefer that fsnotify_data_inode() knows
how to handle FSNOTIFY_EVENT_ERROR type.
You will need it if you choose to implement my proposal of optional
FAN_EVENT_INFO_TYPE_FID record.
Thanks,
Amir.
