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| author | David Jeffery <djeffery@redhat.com> | 2023-10-02 14:32:29 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-10 22:02:56 +0200 |
| commit | bb39b7c7869d17cd19d7c62e778613f92282561b (patch) | |
| tree | d180243fce4104188af7960bf77d472ab2cbba7e | |
| parent | 3f3164ce6396138747984ee9e61158e248246300 (diff) | |
| download | linux-stable-bb39b7c7869d17cd19d7c62e778613f92282561b.tar.gz linux-stable-bb39b7c7869d17cd19d7c62e778613f92282561b.tar.bz2 linux-stable-bb39b7c7869d17cd19d7c62e778613f92282561b.zip | |
md/raid5: release batch_last before waiting for another stripe_head
commit 2fd7b0f6d5ad655b1d947d3acdd82f687c31465e upstream.
When raid5_get_active_stripe is called with a ctx containing a stripe_head in
its batch_last pointer, it can cause a deadlock if the task sleeps waiting on
another stripe_head to become available. The stripe_head held by batch_last
can be blocking the advancement of other stripe_heads, leading to no
stripe_heads being released so raid5_get_active_stripe waits forever.
Like with the quiesce state handling earlier in the function, batch_last
needs to be released by raid5_get_active_stripe before it waits for another
stripe_head.
Fixes: 3312e6c887fe ("md/raid5: Keep a reference to last stripe_head for batch")
Cc: stable@vger.kernel.org # v6.0+
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231002183422.13047-1-djeffery@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/raid5.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 85b3004594e0..e6ac4d0d94d8 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -854,6 +854,13 @@ struct stripe_head *raid5_get_active_stripe(struct r5conf *conf, set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state); r5l_wake_reclaim(conf->log, 0); + + /* release batch_last before wait to avoid risk of deadlock */ + if (ctx && ctx->batch_last) { + raid5_release_stripe(ctx->batch_last); + ctx->batch_last = NULL; + } + wait_event_lock_irq(conf->wait_for_stripe, is_inactive_blocked(conf, hash), *(conf->hash_locks + hash)); |