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 04/12] docs: path-lookup: update do_last() part
Date: Tue, 26 Jan 2021 15:24:35 +0800 [thread overview]
Message-ID: <20210126072443.33066-5-foxhlchen@gmail.com> (raw)
In-Reply-To: <20210126072443.33066-1-foxhlchen@gmail.com>
traling_symlink() was merged into lookup_last, do_last().
do_last() has later been split into open_last_lookups()
and do_open().
see related commit: c5971b8c6354a95c9ee7eb722928af5000bac247
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
---
Documentation/filesystems/path-lookup.rst | 34 +++++++++++------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/Documentation/filesystems/path-lookup.rst b/Documentation/filesystems/path-lookup.rst
index 4e77c8520fa9..1f05b1417a55 100644
--- a/Documentation/filesystems/path-lookup.rst
+++ b/Documentation/filesystems/path-lookup.rst
@@ -496,11 +496,11 @@ one provided by a dead NFS server. In the current kernel, path_mountpoint
has been merged into ``path_lookup_at()`` with a new flag LOOKUP_MOUNTPOINT.
Finally ``path_openat()`` is used for the ``open()`` system call; it
-contains, in support functions starting with "``do_last()``", all the
+contains, in support functions starting with "``open_last_lookups()``", all the
complexity needed to handle the different subtleties of O_CREAT (with
or without O_EXCL), final "``/``" characters, and trailing symbolic
links. We will revisit this in the final part of this series, which
-focuses on those symbolic links. "``do_last()``" will sometimes, but
+focuses on those symbolic links. "``open_last_lookups()``" will sometimes, but
not always, take ``i_rwsem``, depending on what it finds.
Each of these, or the functions which call them, need to be alert to
@@ -1201,26 +1201,26 @@ symlink.
This case is handled by the relevant caller of ``link_path_walk()``, such as
``path_lookupat()`` using a loop that calls ``link_path_walk()``, and then
handles the final component. If the final component is a symlink
-that needs to be followed, then ``trailing_symlink()`` is called to set
-things up properly and the loop repeats, calling ``link_path_walk()``
-again. This could loop as many as 40 times if the last component of
-each symlink is another symlink.
+that needs to be followed, then ``open_last_lookups()`` and ``do_open()`` is
+called to set things up properly and the loop repeats, calling
+``link_path_walk()`` again. This could loop as many as 40 times if the last
+component of each symlink is another symlink.
The various functions that examine the final component and possibly
-report that it is a symlink are ``lookup_last()``, ``mountpoint_last()``
-and ``do_last()``, each of which use the same convention as
-``walk_component()`` of returning ``1`` if a symlink was found that needs
-to be followed.
+report that it is a symlink are ``lookup_last()``, ``open_last_lookups()``
+, each of which use the same convention as
+``walk_component()`` of returning ``char *name`` if a symlink was found that
+needs to be followed.
-Of these, ``do_last()`` is the most interesting as it is used for
-opening a file. Part of ``do_last()`` runs with ``i_rwsem`` held and this
-part is in a separate function: ``lookup_open()``.
+Of these, ``open_last_lookups()``, ``do_open()`` is the most interesting as it is
+used for opening a file. Part of ``open_last_lookups()`` runs with ``i_rwsem``
+held and this part is in a separate function: ``lookup_open()``.
-Explaining ``do_last()`` completely is beyond the scope of this article,
-but a few highlights should help those interested in exploring the
-code.
+Explaining ``open_last_lookups()``, ``do_open()`` completely is beyond the scope
+of this article, but a few highlights should help those interested in exploring
+the code.
-1. Rather than just finding the target file, ``do_last()`` needs to open
+1. Rather than just finding the target file, ``do_open()`` needs to open
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
--
2.30.0
next prev parent reply other threads:[~2021-01-26 17:30 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 ` Fox Chen [this message]
2021-01-28 3:50 ` [PATCH 04/12] docs: path-lookup: update do_last() part 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 ` [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
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