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 [thread overview]
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
next prev parent reply other threads:[~2021-03-16 5:48 UTC|newest]
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
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