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| author | Fox Chen <foxhlchen@gmail.com> | 2021-05-27 17:16:17 +0800 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2021-06-18 11:36:08 -0600 |
| commit | ef4aa53f36a932e656a3b91cdc8a9a9dcb9cef81 (patch) | |
| tree | 9bde574ebc4685c2381d4671b3d8217df529b663 /Documentation | |
| parent | 3c1be84b8d82959a6b7fedb598b8781fa1d09421 (diff) | |
docs: path-lookup: update symlink description
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>
Reviewed-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20210527091618.287093-13-foxhlchen@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/filesystems/path-lookup.rst | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/Documentation/filesystems/path-lookup.rst b/Documentation/filesystems/path-lookup.rst index c150f076abbf..b746e974393a 100644 --- a/Documentation/filesystems/path-lookup.rst +++ b/Documentation/filesystems/path-lookup.rst @@ -1200,16 +1200,15 @@ 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 ``-ESTALE`` is returned. 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:: @@ -1219,8 +1218,8 @@ 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 |