diff options
| author | Lukas Schauer <lukas@schauer.dev> | 2023-12-01 11:11:28 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-12-12 14:24:54 +0100 |
| commit | e95aada4cb93d42e25c30a0ef9eb2923d9711d4a (patch) | |
| tree | 5c8f7f49d6d6ce84d88d4f6da4996ab582369356 /fs/pipe.c | |
| parent | fs/pipe: Fix lockdep false-positive in watchqueue pipe_write() (diff) | |
| download | linux-e95aada4cb93d42e25c30a0ef9eb2923d9711d4a.tar.xz linux-e95aada4cb93d42e25c30a0ef9eb2923d9711d4a.zip | |
pipe: wakeup wr_wait after setting max_usage
Commit c73be61cede5 ("pipe: Add general notification queue support") a
regression was introduced that would lock up resized pipes under certain
conditions. See the reproducer in [1].
The commit resizing the pipe ring size was moved to a different
function, doing that moved the wakeup for pipe->wr_wait before actually
raising pipe->max_usage. If a pipe was full before the resize occured it
would result in the wakeup never actually triggering pipe_write.
Set @max_usage and @nr_accounted before waking writers if this isn't a
watch queue.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212295 [1]
Link: https://lore.kernel.org/r/20231201-orchideen-modewelt-e009de4562c6@brauner
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Lukas Schauer <lukas@schauer.dev>
[Christian Brauner <brauner@kernel.org>: rewrite to account for watch queues]
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/pipe.c')
| -rw-r--r-- | fs/pipe.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 226e7f66b590..8d9286a1f2e8 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1324,6 +1324,11 @@ int pipe_resize_ring(struct pipe_inode_info *pipe, unsigned int nr_slots) pipe->tail = tail; pipe->head = head; + if (!pipe_has_watch_queue(pipe)) { + pipe->max_usage = nr_slots; + pipe->nr_accounted = nr_slots; + } + spin_unlock_irq(&pipe->rd_wait.lock); /* This might have made more room for writers */ @@ -1375,8 +1380,6 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned int arg) if (ret < 0) goto out_revert_acct; - pipe->max_usage = nr_slots; - pipe->nr_accounted = nr_slots; return pipe->max_usage * PAGE_SIZE; out_revert_acct: |