Re: [PATCH 06/11] fsnotify: Support FS_ERROR event type

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 <redacted>

---
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)