mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-05 00:25:24 -04:00
dab17c1add
Because parsing of the directory wasn't being done under any sort of lock,
the pages holding the directory content can get invalidated whilst the
parsing is ongoing.
Further, the directory page check function gets called outside of the page
lock, so if the page gets cleared or updated, this may return reports of
bad magic numbers in the directory page.
Also, the directory may change size whilst checking and parsing are
ongoing, so more care needs to be taken here.
Fix this by:
(1) Perform the page check from the page filling function before we set
PageUptodate and drop the page lock.
(2) Check for the file having shrunk and the page having been abandoned
before checking the page contents.
(3) Lock the page whilst parsing it for the directory iterator.
Whilst we're at it, add a tracepoint to report check failure.
Signed-off-by: David Howells <dhowells@redhat.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.