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 12/12] docs: path-lookup: update symlink description
Date: Tue, 26 Jan 2021 15:24:43 +0800 [thread overview]
Message-ID: <20210126072443.33066-13-foxhlchen@gmail.com> (raw)
In-Reply-To: <20210126072443.33066-1-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 2bb3ca486acd..0c6fc296056c 100644
--- a/Documentation/filesystems/path-lookup.rst
+++ b/Documentation/filesystems/path-lookup.rst
@@ -1204,16 +1204,15 @@ 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::
@@ -1223,8 +1222,8 @@ 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
--
2.30.0
next prev parent reply other threads:[~2021-01-26 17:35 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 ` [PATCH 07/12] docs: path-lookup: i_op->follow_link replaced with i_op->get_link Fox Chen
2021-01-28 3:53 ` 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 ` Fox Chen [this message]
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
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