->last_type values are set in 3 places: path_init() (sets to LAST_ROOT),
link_path_walk (LAST_NORM/DOT/DOTDOT) and pick_link (LAST_BIND).
The are checked in walk_component(), lookup_last() and do_last().
They also get copied to the caller by filename_parentat(). In the last
3 cases the value is what we had at the return from link_path_walk().
In case of walk_component() it's either directly downstream from
assignment in link_path_walk() or, when called by lookup_last(), the
value we have at the return from link_path_walk().
The value at the entry into link_path_walk() can survive to return only
if the pathname contains nothing but slashes. Note that pick_link()
never returns such - pure jumps are handled directly. So for the calls
of link_path_walk() for trailing symlinks it does not matter what value
had been there at the entry; the value at the return won't depend upon it.
There are 3 call chains that might have pick_link() storing LAST_BIND:
1) pick_link() from step_into() from walk_component() from
link_path_walk(). In that case we will either be parsing the next
component immediately after return into link_path_walk(), which will
overwrite the ->last_type before anyone has a chance to look at it,
or we'll fail, in which case nobody will be looking at ->last_type at all.
2) pick_link() from step_into() from walk_component() from lookup_last().
The value is never looked at due to the above; it won't affect the value
seen at return from any link_path_walk().
3) pick_link() from step_into() from do_last(). Ditto.
In other words, assignemnt in pick_link() is pointless, and so is
LAST_BIND itself; nothing ever looks at that value. Kill it off.
And make link_path_walk() _always_ assign ->last_type - in the only
case when the value at the entry might survive to the return that value
is always LAST_ROOT, inherited from path_init(). Move that assignment
from path_init() into the beginning of link_path_walk(), to consolidate
the things.
Historical note: LAST_BIND used to be used for the kludge with trailing
pure jump symlinks (extra iteration through the top-level loop).
No point keeping it anymore...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that we have new LOOKUP flags, we should document them in the
relevant path-walking documentation. And now that we've settled on a
common name for nd_jump_link() style symlinks ("magic links"), use that
term where magic-link semantics are described.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Documentation/filesystems is, like much of the rest of the kernel's
documentation, a jumble of unorganized information. Split the
documentation into categories and try to bring some order to the top-level
index.rst files. No text changes other than a few section-introductory
blurbs; this is all just moving stuff around.
Cc: linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix Sphinx warnings in path-lookup.rst:
Documentation/filesystems/path-lookup.rst:347: WARNING: Title underline too short.
Documentation/filesystems/path-lookup.rst:358: WARNING: Title underline too short.
[...]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Get rid of some unneeded structural elements around the new (to RST)
pathname-lookup document.
Signed-off-by: NeilBrown <neilb@suse.com>
[ jc: grabbed from email and changelog added ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This allows the document to be integrated with the main documentation
tree.
Changes include:
- rename from .md to .rst
- use `` for code, not single `
- use correct sub-section marking
- fix indented blocks, both code and non-code
- fix external-link markup
Signed-off-by: NeilBrown <neilb@suse.com>
[jc: changed the toctree organization a bit]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
