Re: [PATCH v4 4/4] vfs: add notifications for mount attribute change
From: Amir Goldstein <amir73il@gmail.com>
Date: 2025-01-24 09:10:11
Also in:
linux-fsdevel
On Thu, Jan 23, 2025 at 8:41 PM Miklos Szeredi [off-list ref] wrote:
Notify when mount flags, propagation or idmap changes. Just like attach and detach, no details are given in the notification, only the mount ID. Signed-off-by: Miklos Szeredi <redacted> ---
My only nit this time is that I prefer the fsnotify/fanotify bits here to be in patches 1,2 which as you write, only add the infrastructure to be used later. [...]
quoted hunk ↗ jump to hunk
--- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h@@ -471,7 +471,7 @@ static inline bool fanotify_is_error_event(u32 mask) static inline bool fanotify_is_mnt_event(u32 mask) { - return mask & (FAN_MNT_ATTACH | FAN_MNT_DETACH); + return mask & FANOTIFY_MOUNT_EVENTS; }
This should have used the macro from the first use in patch 2. [...]
quoted hunk ↗ jump to hunk
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 6c3e3a4a7b10..54e01803e309 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h@@ -58,6 +58,8 @@ #define FS_MNT_ATTACH 0x01000000 /* Mount was attached */ #define FS_MNT_DETACH 0x02000000 /* Mount was detached */ +#define FS_MNT_CHANGE 0x04000000 /* Mount was changed */ + #define FS_MNT_MOVE (FS_MNT_ATTACH | FS_MNT_DETACH) /*@@ -106,7 +108,8 @@ FS_EVENTS_POSS_ON_CHILD | \ FS_DELETE_SELF | FS_MOVE_SELF | \ FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \ - FS_ERROR | FS_MNT_ATTACH | FS_MNT_DETACH) + FS_ERROR | \ + FS_MNT_ATTACH | FS_MNT_DETACH | FS_MNT_CHANGE )
Please add those bits as a group in patch 1:
@@ -80,6 +80,9 @@ */ #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE |
FS_RENAME)
+/* Mount namespace events */
+#define FSNOTIFY_MNT_EVENTS (FS_MNT_ATTACH | FS_MNT_DETACH | FS_MNT_CHANGE)
+
/* Content events can be used to inspect file content */
#define FSNOTIFY_CONTENT_PERM_EVENTS (FS_OPEN_PERM | FS_OPEN_EXEC_PERM | \
FS_ACCESS_PERM)@@ -108,6 +111,7 @@ /* Events that can be reported to backends */ #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ + FSNOTIFY_MNT_EVENTS | \ FS_EVENTS_POSS_ON_CHILD | \
I am aware of the inconsistency of the names ALL_FSNOTIFY_* and FSNOTIFY_* but if you look at master as of last night you will find: FSNOTIFY_CONTENT_PERM_EVENTS and FSNOTIFY_PRE_CONTENT_EVENTS (please rebase) One day we may cleanup ALL_FSNOTIFY_DIRENT_EVENTS and ALL_FSNOTIFY_PERM_EVENTS to conform. Thanks, Amir.