mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2025-01-10 15:58:47 +00:00
7d1cf5e624
When a file is opened and created with open(..., O_CREAT) we get
both the CREATE and OPEN fsnotify events and would expect them in that
order. For most filesystems we get them in that order because
open_last_lookups() calls fsnofify_create() and then do_open() (from
path_openat()) calls vfs_open()->do_dentry_open() which calls
fsnotify_open().
However when ->atomic_open is used, the
do_dentry_open() -> fsnotify_open()
call happens from finish_open() which is called from the ->atomic_open
handler in lookup_open() which is called *before* open_last_lookups()
calls fsnotify_create. So we get the "open" notification before
"create" - which is backwards. ltp testcase inotify02 tests this and
reports the inconsistency.
This patch lifts the fsnotify_open() call out of do_dentry_open() and
places it higher up the call stack. There are three callers of
do_dentry_open().
For vfs_open() and kernel_file_open() the fsnotify_open() is placed
directly in that caller so there should be no behavioural change.
For finish_open() there are two cases:
- finish_open is used in ->atomic_open handlers. For these we add a
call to fsnotify_open() at open_last_lookups() if FMODE_OPENED is
set - which means do_dentry_open() has been called.
- finish_open is used in ->tmpfile() handlers. For these a similar
call to fsnotify_open() is added to vfs_tmpfile()
With this patch NFSv3 is restored to its previous behaviour (before
->atomic_open support was added) of generating CREATE notifications
before OPEN, and NFSv4 now has that same correct ordering that is has
not had before. I haven't tested other filesystems.
Fixes: 7c6c5249f061 ("NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly.")
Reported-by: James Clark <james.clark@arm.com>
Closes: https://lore.kernel.org/all/01c3bf2e-eb1f-4b7f-a54f-d2a05dd3d8c8@arm.com
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/171817619547.14261.975798725161704336@noble.neil.brown.name
Fixes: 7b8c9d7bb457 ("fsnotify: move fsnotify_open() hook into do_dentry_open()")
Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240617162303.1596-2-jack@suse.cz
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.