linux-doc.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Fox Chen <foxhlchen@gmail.com>
To: corbet@lwn.net, vegard.nossum@oracle.com,
	viro@zeniv.linux.org.uk, rdunlap@infradead.org,
	grandmaster@al2klimov.de
Cc: Fox Chen <foxhlchen@gmail.com>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 07/12] docs: path-lookup: i_op->follow_link replaced with i_op->get_link
Date: Tue, 26 Jan 2021 15:24:38 +0800	[thread overview]
Message-ID: <20210126072443.33066-8-foxhlchen@gmail.com> (raw)
In-Reply-To: <20210126072443.33066-1-foxhlchen@gmail.com>

follow_link has been replaced by get_link() which can be
called in RCU mode.

see commit: 6b2553918d8b4e6de9853fd6315bec7271a2e592

Signed-off-by: Fox Chen <foxhlchen@gmail.com>
---
 Documentation/filesystems/path-lookup.rst | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/Documentation/filesystems/path-lookup.rst b/Documentation/filesystems/path-lookup.rst
index 25d2a5a59f45..0a362849b26f 100644
--- a/Documentation/filesystems/path-lookup.rst
+++ b/Documentation/filesystems/path-lookup.rst
@@ -1062,13 +1062,11 @@ filesystem cannot successfully get a reference in RCU-walk mode, it
 must return ``-ECHILD`` and ``unlazy_walk()`` will be called to return to
 REF-walk mode in which the filesystem is allowed to sleep.
 
-The place for all this to happen is the ``i_op->follow_link()`` inode
-method.  In the present mainline code this is never actually called in
-RCU-walk mode as the rewrite is not quite complete.  It is likely that
-in a future release this method will be passed an ``inode`` pointer when
-called in RCU-walk mode so it both (1) knows to be careful, and (2) has the
-validated pointer.  Much like the ``i_op->permission()`` method we
-looked at previously, ``->follow_link()`` would need to be careful that
+The place for all this to happen is the ``i_op->get_link()`` inode
+method. This is called both in RCU-walk and REF-walk. In RCU-walk the
+``dentry*`` argument is NULL, ``->get_link()`` can return -ECHILD to drop
+RCU-walk.  Much like the ``i_op->permission()`` method we
+looked at previously, ``->get_link()`` would need to be careful that
 all the data structures it references are safe to be accessed while
 holding no counted reference, only the RCU lock.  Though getting a
 reference with ``->follow_link()`` is not yet done in RCU-walk mode, the
-- 
2.30.0


  parent reply	other threads:[~2021-01-26 18:54 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-26  7:24 [PATCH 00/12] docs: path-lookup: Update pathlookup docs Fox Chen
2021-01-26  7:24 ` [PATCH 01/12] docs: path-lookup: update follow_managed() part Fox Chen
2021-01-26 14:03   ` Greg KH
2021-01-27  1:11     ` Fox Chen
2021-01-28  3:20   ` NeilBrown
2021-01-26  7:24 ` [PATCH 02/12] docs: path-lookup: update path_to_nameidata() parth Fox Chen
2021-01-28  3:24   ` NeilBrown
2021-01-26  7:24 ` [PATCH 03/12] docs: path-lookup: update path_mountpoint() part Fox Chen
2021-01-28  3:28   ` NeilBrown
2021-01-26  7:24 ` [PATCH 04/12] docs: path-lookup: update do_last() part Fox Chen
2021-01-28  3:50   ` NeilBrown
2021-01-26  7:24 ` [PATCH 05/12] docs: path-lookup: remove filename_mountpoint Fox Chen
2021-01-26  7:24 ` [PATCH 06/12] docs: path-lookup: Add macro name to symlink limit description Fox Chen
2021-01-26  7:24 ` Fox Chen [this message]
2021-01-28  3:53   ` [PATCH 07/12] docs: path-lookup: i_op->follow_link replaced with i_op->get_link NeilBrown
2021-01-26  7:24 ` [PATCH 08/12] docs: path-lookup: update i_op->put_link and cookie description Fox Chen
2021-01-28  3:50   ` NeilBrown
2021-01-26  7:24 ` [PATCH 09/12] docs: path-lookup: no get_link() Fox Chen
2021-01-26  7:24 ` [PATCH 10/12] docs: path-lookup: update WALK_GET, WALK_PUT desc Fox Chen
2021-01-26  7:24 ` [PATCH 11/12] docs: path-lookup: update get_link() ->follow_link description Fox Chen
2021-01-26  7:24 ` [PATCH 12/12] docs: path-lookup: update symlink description Fox Chen
2021-01-26  7:30 ` [PATCH 00/12] docs: path-lookup: Update pathlookup docs Fox Chen
2021-01-26 20:31 ` Jonathan Corbet
2021-01-28  1:23   ` Fox Chen
2021-01-28  3:58 ` NeilBrown
2021-01-29  1:29   ` Fox Chen

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=20210126072443.33066-8-foxhlchen@gmail.com \
    --to=foxhlchen@gmail.com \
    --cc=corbet@lwn.net \
    --cc=grandmaster@al2klimov.de \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rdunlap@infradead.org \
    --cc=vegard.nossum@oracle.com \
    --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).