]> www.infradead.org Git - users/jedix/linux-maple.git/commit
fs: delay sysctl_nr_open check in expand_files()
authorMateusz Guzik <mjguzik@gmail.com>
Sat, 16 Nov 2024 06:41:28 +0000 (07:41 +0100)
committerChristian Brauner <brauner@kernel.org>
Mon, 2 Dec 2024 10:24:49 +0000 (11:24 +0100)
commita48bdf80ce6938f8c1de6a56fed7c4f6f46904e9
treef04be21997dc78c5a4d80deb21742d785d594ae5
parent40384c840ea1944d7c5a392e8975ed088ecf0b37
fs: delay sysctl_nr_open check in expand_files()

Suppose a thread sharing the table started a resize, while
sysctl_nr_open got lowered to a value which prohibits it. This is still
going to go through with and without the patch, which is fine.

Further suppose another thread shows up to do a matching expansion while
resize_in_progress == true. It is going to error out since it performs
the sysctl_nr_open check *before* finding out if there is an expansion
in progress. But the aformentioned thread is going to succeded, so the
error is spurious (and it would not happen if the thread showed up a
little bit later).

Checking the sysctl *after* we know there are no pending updates sorts
it out.

While here annotate the thing as unlikely.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20241116064128.280870-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
fs/file.c