2021-07-20 16:13:26

by Gabriel Krisman Bertazi

[permalink] [raw]
Subject: [PATCH v4 11/16] 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_FS_ERROR events.

Reviewed-by: Amir Goldstein <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>

---
Changes since v2:
- FAN_ERROR->FAN_FS_ERROR (Amir)

Changes since v1:
- Overload FS_ERROR with FS_IN_IGNORED
- Implement support for this type on fsnotify_data_inode (Amir)
---
include/linux/fsnotify_backend.h | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index ff2cf04c7496..33988fdf391a 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 | \
@@ -263,6 +270,12 @@ 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)
@@ -272,6 +285,8 @@ static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
return (struct inode *)data;
case FSNOTIFY_EVENT_PATH:
return d_inode(((const struct path *)data)->dentry);
+ case FSNOTIFY_EVENT_ERROR:
+ return ((struct fs_error_report *)data)->inode;
default:
return NULL;
}
--
2.32.0