From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: dhowells@redhat.com, Casey Schaufler <casey@schaufler-ca.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
nicolas.dichtel@6wind.com, raven@themaw.net,
Christian Brauner <christian@brauner.io>,
dhowells@redhat.com, keyrings@vger.kernel.org,
linux-usb@vger.kernel.org, linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
linux-block@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/6] Adjust watch_queue documentation to mention mount and superblock watches. [ver #5]
Date: Fri, 28 Jun 2019 16:50:35 +0100 [thread overview]
Message-ID: <156173703546.15650.14319137940607993268.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <156173701358.15650.8735203424342507015.stgit@warthog.procyon.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
---
Documentation/watch_queue.rst | 20 +++++++++++++++++++-
drivers/misc/Kconfig | 5 +++--
2 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/Documentation/watch_queue.rst b/Documentation/watch_queue.rst
index 4087a8e670a8..1bec2018d549 100644
--- a/Documentation/watch_queue.rst
+++ b/Documentation/watch_queue.rst
@@ -13,6 +13,10 @@ receive notifications from the kernel. This can be used in conjunction with::
* USB subsystem event notifications
+ * Mount topology change notifications
+
+ * Superblock event notifications
+
The notifications buffers can be enabled by:
@@ -324,6 +328,19 @@ Any particular buffer can be fed from multiple sources. Sources include:
for buses and devices. Watchpoints of this type are set on the global
device watch list.
+ * WATCH_TYPE_MOUNT_NOTIFY
+
+ Notifications of this type indicate mount tree topology changes and mount
+ attribute changes. A watch can be set on a particular file or directory
+ and notifications from the path subtree rooted at that point will be
+ intercepted.
+
+ * WATCH_TYPE_SB_NOTIFY
+
+ Notifications of this type indicate superblock events, such as quota limits
+ being hit, I/O errors being produced or network server loss/reconnection.
+ Watches of this type are set directly on superblocks.
+
Event Filtering
===============
@@ -365,7 +382,8 @@ Where:
(watch.info & info_mask) == info_filter
This could be used, for example, to ignore events that are not exactly on
- the watched point in a mount tree.
+ the watched point in a mount tree by specifying NOTIFY_MOUNT_IN_SUBTREE
+ must be 0.
* ``subtype_filter`` is a bitmask indicating the subtypes that are of
interest. Bit 0 of subtype_filter[0] corresponds to subtype 0, bit 1 to
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index e53f88783fe7..8b13103b17c0 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -11,8 +11,9 @@ config WATCH_QUEUE
help
This is a general notification queue for the kernel to pass events to
userspace through a mmap()'able ring buffer. It can be used in
- conjunction with watches for key/keyring change notifications and device
- notifications.
+ conjunction with watches for key/keyring change notifications, device
+ notifications, mount topology change notifications, and superblock
+ change notifications.
Note that in theory this should work fine with NOMMU, but I'm not
sure how to make that work.
next prev parent reply other threads:[~2019-06-28 15:50 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-28 15:50 [PATCH 0/6] Mount and superblock notifications [ver #5] David Howells
2019-06-28 15:50 ` [PATCH 1/6] security: Add hooks to rule on setting a superblock or mount watch " David Howells
2019-07-12 20:11 ` James Morris
2019-06-28 15:50 ` David Howells [this message]
2019-07-01 2:59 ` [PATCH 2/6] Adjust watch_queue documentation to mention mount and superblock watches. " Randy Dunlap
2019-07-01 8:52 ` David Howells
2019-07-01 14:52 ` Randy Dunlap
2019-06-28 15:50 ` [PATCH 3/6] vfs: Add a mount-notification facility " David Howells
2019-06-28 15:50 ` [PATCH 4/6] vfs: Add superblock notifications " David Howells
2019-06-28 15:51 ` [PATCH 5/6] fsinfo: Export superblock notification counter " David Howells
2019-06-28 15:51 ` [PATCH 6/6] Add sample notification program " David Howells
2019-06-28 16:47 ` [PATCH 0/6] Mount and superblock notifications " David Howells
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=156173703546.15650.14319137940607993268.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=casey@schaufler-ca.com \
--cc=christian@brauner.io \
--cc=gregkh@linuxfoundation.org \
--cc=keyrings@vger.kernel.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=nicolas.dichtel@6wind.com \
--cc=raven@themaw.net \
--cc=sds@tycho.nsa.gov \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).