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From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: dhowells@redhat.com, torvalds@linux-foundation.org,
	raven@themaw.net, mszeredi@redhat.com, christian@brauner.io,
	jannh@google.com, darrick.wong@oracle.com, kzak@redhat.com,
	jlayton@redhat.com, linux-api@vger.kernel.org,
	linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 09/18] watch_queue: Mount event counters [ver #21]
Date: Mon, 03 Aug 2020 14:37:42 +0100	[thread overview]
Message-ID: <159646186240.1784947.2050531865230554652.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <159646178122.1784947.11705396571718464082.stgit@warthog.procyon.org.uk>

Add three event counters to each mount object:

 (1) mnt_topology_changes.

     Counts the number of changes to the mount tree topology, including
     addition of new mount objects, removal of mount objects and mount
     objects being moved about.

 (2) mnt_attr_changes.

     Counts the number of changes to a mount object's attributes, such as
     whether or not the device files it contains are interpretable as such.

 (3) mnt_subtree_notifications.

     Counts the number of events within the mount subtree at this point.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/mount.h        |    3 +++
 fs/mount_notify.c |    4 ++++
 2 files changed, 7 insertions(+)

diff --git a/fs/mount.h b/fs/mount.h
index 1037781be055..9758a9fa8f69 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -83,6 +83,9 @@ struct mount {
 	u64	mnt_unique_id;		/* ID unique over lifetime of kernel */
 #endif
 #ifdef CONFIG_MOUNT_NOTIFICATIONS
+	atomic_long_t mnt_topology_changes;	/* Number of topology changes applied */
+	atomic_long_t mnt_attr_changes;		/* Number of attribute changes applied */
+	atomic_long_t mnt_subtree_notifications; /* Number of notifications in subtree */
 	struct watch_list *mnt_watchers; /* Watches on dentries within this mount */
 #endif
 } __randomize_layout;
diff --git a/fs/mount_notify.c b/fs/mount_notify.c
index d8ba66ed5f77..57eebae51cb1 100644
--- a/fs/mount_notify.c
+++ b/fs/mount_notify.c
@@ -61,6 +61,7 @@ static void post_mount_notification(struct mount *changed,
 			cursor.dentry = READ_ONCE(mnt->mnt_mountpoint);
 			mnt = parent;
 			cursor.mnt = &mnt->mnt;
+			atomic_long_inc(&mnt->mnt_subtree_notifications);
 		} else {
 			cursor.dentry = cursor.dentry->d_parent;
 		}
@@ -96,6 +97,7 @@ void notify_mount(struct mount *trigger,
 	case NOTIFY_MOUNT_EXPIRY:
 	case NOTIFY_MOUNT_READONLY:
 	case NOTIFY_MOUNT_SETATTR:
+		atomic_long_inc(&trigger->mnt_attr_changes);
 		break;
 
 	case NOTIFY_MOUNT_NEW_MOUNT:
@@ -103,6 +105,8 @@ void notify_mount(struct mount *trigger,
 	case NOTIFY_MOUNT_MOVE_FROM:
 	case NOTIFY_MOUNT_MOVE_TO:
 		n.auxiliary_mount = aux->mnt_unique_id;
+		atomic_long_inc(&trigger->mnt_topology_changes);
+		atomic_long_inc(&aux->mnt_topology_changes);
 		break;
 
 	default:



  parent reply	other threads:[~2020-08-03 13:37 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-03 13:36 [PATCH 00/18] VFS: Filesystem information " David Howells
2020-08-03 13:36 ` [PATCH 01/18] fsinfo: Introduce a non-repeating system-unique superblock ID " David Howells
2020-08-04  9:34   ` Miklos Szeredi
2020-08-03 13:36 ` [PATCH 02/18] fsinfo: Add fsinfo() syscall to query filesystem information " David Howells
2020-08-04 10:16   ` Miklos Szeredi
2020-08-04 11:34   ` David Howells
2020-08-27 11:27   ` Michael Kerrisk (man-pages)
2020-08-03 13:36 ` [PATCH 03/18] fsinfo: Provide a bitmap of the features a filesystem supports " David Howells
2020-08-03 13:37 ` [PATCH 04/18] fsinfo: Allow retrieval of superblock devname, options and stats " David Howells
2020-08-03 13:37 ` [PATCH 05/18] fsinfo: Allow fsinfo() to look up a mount object by ID " David Howells
2020-08-04 10:33   ` Miklos Szeredi
2020-08-03 13:37 ` [PATCH 06/18] fsinfo: Add a uniquifier ID to struct mount " David Howells
2020-08-04 10:41   ` Miklos Szeredi
2020-08-04 12:32     ` Ian Kent
2020-08-05 14:13   ` David Howells
2020-08-05 14:46     ` Miklos Szeredi
2020-08-05 15:30     ` David Howells
2020-08-05 19:33       ` Matthew Wilcox
2020-08-06  5:43         ` Ian Kent
2020-08-03 13:37 ` [PATCH 07/18] fsinfo: Allow mount information to be queried " David Howells
2020-08-03 13:37 ` [PATCH 08/18] fsinfo: Allow mount topology and propagation info to be retrieved " David Howells
2020-08-04 13:38   ` Miklos Szeredi
2020-08-05 15:37   ` David Howells
2020-08-05 17:19     ` Miklos Szeredi
2020-08-03 13:37 ` David Howells [this message]
2020-08-03 13:37 ` [PATCH 10/18] fsinfo: Provide notification overrun handling support " David Howells
2020-08-04 13:56   ` Miklos Szeredi
2020-08-05  2:05     ` Ian Kent
2020-08-05  2:46       ` Ian Kent
2020-08-05  7:45         ` Miklos Szeredi
2020-08-05 11:23           ` Ian Kent
2020-08-05 11:27             ` Miklos Szeredi
2020-08-06  1:47               ` Ian Kent
2020-08-05 16:06   ` David Howells
2020-08-05 17:26     ` Miklos Szeredi
2020-08-03 13:37 ` [PATCH 11/18] fsinfo: sample: Mount listing program " David Howells
2020-08-03 13:38 ` [PATCH 12/18] fsinfo: Add API documentation " David Howells
2020-08-03 13:38 ` [PATCH 13/18] fsinfo: Add support for AFS " David Howells
2020-08-03 13:38 ` [PATCH 14/18] fsinfo: Add support to ext4 " David Howells
2020-08-03 13:38 ` [PATCH 15/18] fsinfo: Add an attribute that lists all the visible mounts in a namespace " David Howells
2020-08-04 14:05   ` Miklos Szeredi
2020-08-05  0:59     ` Ian Kent
2020-08-05 16:44   ` David Howells
2020-08-03 13:38 ` [PATCH 16/18] errseq: add a new errseq_scrape function " David Howells
2020-08-03 13:38 ` [PATCH 17/18] vfs: allow fsinfo to fetch the current state of s_wb_err " David Howells
2020-08-03 13:39 ` [PATCH 18/18] samples: add error state information to test-fsinfo.c " David Howells
2020-08-04 15:39 ` [PATCH 00/18] VFS: Filesystem information " James Bottomley
2020-08-04 19:18   ` Miklos Szeredi
2020-08-05 17:13 ` David Howells

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