Linux-Doc Archive on lore.kernel.org
 help / color / Atom feed
From: Fox Chen <foxhlchen@gmail.com>
To: neilb@suse.de
Cc: Fox Chen <foxhlchen@gmail.com>,
	corbet@lwn.net, vegard.nossum@oracle.com,
	viro@zeniv.linux.org.uk, rdunlap@infradead.org,
	grandmaster@al2klimov.de, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org
Subject: [PATCH v2 12/12] docs: path-lookup: update symlink description
Date: Tue, 16 Mar 2021 13:47:27 +0800
Message-ID: <20210316054727.25655-13-foxhlchen@gmail.com> (raw)
In-Reply-To: <20210316054727.25655-1-foxhlchen@gmail.com>

instead of lookup_real()/vfs_create(), i_op->lookup() and
i_op->create() will be called directly.

update vfs_open() logic

should_follow_link is merged into lookup_last() or open_last_lookup()
which returns symlink name instead of an integer.

Signed-off-by: Fox Chen <foxhlchen@gmail.com>
---
 Documentation/filesystems/path-lookup.rst | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/Documentation/filesystems/path-lookup.rst b/Documentation/filesystems/path-lookup.rst
index eef6e9f68fba..adbc714740c2 100644
--- a/Documentation/filesystems/path-lookup.rst
+++ b/Documentation/filesystems/path-lookup.rst
@@ -1202,16 +1202,15 @@ the code.
    it.  If the file was found in the dcache, then ``vfs_open()`` is used for
    this.  If not, then ``lookup_open()`` will either call ``atomic_open()`` (if
    the filesystem provides it) to combine the final lookup with the open, or
-   will perform the separate ``lookup_real()`` and ``vfs_create()`` steps
+   will perform the separate ``i_op->lookup()`` and ``i_op->create()`` steps
    directly.  In the later case the actual "open" of this newly found or
    created file will be performed by ``vfs_open()``, just as if the name
    were found in the dcache.
 
 2. ``vfs_open()`` can fail with ``-EOPENSTALE`` if the cached information
-   wasn't quite current enough.  Rather than restarting the lookup from
-   the top with ``LOOKUP_REVAL`` set, ``lookup_open()`` is called instead,
-   giving the filesystem a chance to resolve small inconsistencies.
-   If that doesn't work, only then is the lookup restarted from the top.
+   wasn't quite current enough.  If it's in RCU-walk -ECHILD will be returned
+   otherwise will return -ESTALE.  When -ESTALE is returned, the caller may
+   retry with LOOKUP_REVAL flag set.
 
 3. An open with O_CREAT **does** follow a symlink in the final component,
    unlike other creation system calls (like ``mkdir``).  So the sequence::
@@ -1221,8 +1220,8 @@ the code.
 
    will create a file called ``/tmp/bar``.  This is not permitted if
    ``O_EXCL`` is set but otherwise is handled for an O_CREAT open much
-   like for a non-creating open: ``should_follow_link()`` returns ``1``, and
-   so does ``do_last()`` so that ``trailing_symlink()`` gets called and the
+   like for a non-creating open: ``lookup_last()`` or ``open_last_lookup()``
+   returns a non ``Null`` value, and ``link_path_walk()`` gets called and the
    open process continues on the symlink that was found.
 
 Updating the access time
-- 
2.30.2


  parent reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-16  5:47 [PATCH v2 00/12] docs: path-lookup: Update pathlookup docs Fox Chen
2021-03-16  5:47 ` [PATCH v2 01/12] docs: path-lookup: update follow_managed() part Fox Chen
2021-04-19  0:52   ` NeilBrown
2021-04-19  2:17   ` Matthew Wilcox
2021-04-19  2:33     ` Fox Chen
2021-04-19  3:25       ` Matthew Wilcox
2021-04-19  3:33         ` Fox Chen
2021-04-19 19:22           ` Jonathan Corbet
2021-04-20  1:12             ` Fox Chen
2021-03-16  5:47 ` [PATCH v2 02/12] docs: path-lookup: update path_to_nameidata() part Fox Chen
2021-04-19  1:00   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 03/12] docs: path-lookup: update path_mountpoint() part Fox Chen
2021-04-19  1:03   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 04/12] docs: path-lookup: update do_last() part Fox Chen
2021-04-19  1:17   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 05/12] docs: path-lookup: remove filename_mountpoint Fox Chen
2021-04-19  1:20   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 06/12] docs: path-lookup: Add macro name to symlink limit description Fox Chen
2021-04-19  1:22   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 07/12] docs: path-lookup: i_op->follow_link replaced with i_op->get_link Fox Chen
2021-04-19  1:28   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 08/12] docs: path-lookup: update i_op->put_link and cookie description Fox Chen
2021-04-19  1:37   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 09/12] docs: path-lookup: no get_link() Fox Chen
2021-04-19  1:41   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 10/12] docs: path-lookup: update WALK_GET, WALK_PUT desc Fox Chen
2021-04-19  1:47   ` NeilBrown
2021-03-16  5:47 ` [PATCH v2 11/12] docs: path-lookup: update get_link() ->follow_link description Fox Chen
2021-04-19  1:54   ` NeilBrown
2021-03-16  5:47 ` Fox Chen [this message]
2021-04-19  1:59   ` [PATCH v2 12/12] docs: path-lookup: update symlink description NeilBrown
2021-04-19  2:34     ` Fox Chen
2021-04-13 21:18 ` [PATCH v2 00/12] docs: path-lookup: Update pathlookup docs Jonathan Corbet
2021-04-13 22:26   ` NeilBrown

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=20210316054727.25655-13-foxhlchen@gmail.com \
    --to=foxhlchen@gmail.com \
    --cc=corbet@lwn.net \
    --cc=grandmaster@al2klimov.de \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=neilb@suse.de \
    --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

Linux-Doc Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-doc/0 linux-doc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-doc linux-doc/ https://lore.kernel.org/linux-doc \
		linux-doc@vger.kernel.org
	public-inbox-index linux-doc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-doc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git