diff options
| author | David Howells <dhowells@redhat.com> | 2026-07-02 09:23:02 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-07-03 11:52:41 +0200 |
| commit | 5c6ce05e406520290c1d89da97fb3cd70c09137d (patch) | |
| tree | a8d156448b9d572cd8f6b031b4b1a54c47bfd317 | |
| parent | 24dddc384fb9aec2d7eea5463ca6dac98a3b3854 (diff) | |
| download | linux-5c6ce05e406520290c1d89da97fb3cd70c09137d.tar.gz linux-5c6ce05e406520290c1d89da97fb3cd70c09137d.zip | |
netfs: Fix barriering when walking subrequest list
Fix the barriering used when walking the subrequest list in retry as
there's a possibility of seeing a subreq that's just been added by the
application thread.
Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
Fixes: 288ace2f57c9 ("netfs: New writeback implementation")
Link: https://sashiko.dev/#/patchset/20260608145432.681865-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/138807.1782980582@warthog.procyon.org.uk
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
| -rw-r--r-- | fs/netfs/read_retry.c | 7 | ||||
| -rw-r--r-- | fs/netfs/write_retry.c | 7 |
2 files changed, 12 insertions, 2 deletions
diff --git a/fs/netfs/read_retry.c b/fs/netfs/read_retry.c index f59a70f3a086..2b42758e01ec 100644 --- a/fs/netfs/read_retry.c +++ b/fs/netfs/read_retry.c @@ -98,7 +98,12 @@ static void netfs_retry_read_subrequests(struct netfs_io_request *rreq) goto abandon; } - list_for_each_continue(next, &stream->subrequests) { + for (;;) { + /* Read pointer to subreq before reading subreq state. */ + next = smp_load_acquire(&next->next); + if (next == &stream->subrequests) + break; + subreq = list_entry(next, struct netfs_io_subrequest, rreq_link); if (subreq->start + subreq->transferred != start + len || test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags) || diff --git a/fs/netfs/write_retry.c b/fs/netfs/write_retry.c index 32735abfa03f..058bc7a166a5 100644 --- a/fs/netfs/write_retry.c +++ b/fs/netfs/write_retry.c @@ -72,7 +72,12 @@ static void netfs_retry_write_stream(struct netfs_io_request *wreq, !test_bit(NETFS_SREQ_NEED_RETRY, &from->flags)) return; - list_for_each_continue(next, &stream->subrequests) { + for (;;) { + /* Read pointer to subreq before reading subreq state. */ + next = smp_load_acquire(&next->next); + if (next == &stream->subrequests) + break; + subreq = list_entry(next, struct netfs_io_subrequest, rreq_link); if (subreq->start + subreq->transferred != start + len || test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags) || |