Avoid deadlock when removing L2ARC devices under I/O

In case we have I/O and try to remove an L2ARC device a deadlock might
occur. arc_read()->zio_read()->zfs_blkptr_verify() waits for SCL_VDEV
to be dropped while holding the hash_lock. However, spa_l2cache_load()
holds SCL_ALL and waits for the hash_lock in l2arc_evict().

Fix this by moving zfs_blkptr_verify() to the top top arc_read() before
the hash_lock is taken. Verify the block pointer and return a checksum
error if damaged rather than halting the system, by using
BLK_VERIFY_LOG instead of BLK_VERIFY_HALT.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #12054
This commit is contained in:
George Amanakis
2021-06-17 03:17:42 +03:00
committed by GitHub
parent ff31750405
commit 9ffcaa370a
2 changed files with 6 additions and 14 deletions
-3
View File
@@ -1107,9 +1107,6 @@ zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
{
zio_t *zio;
(void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER,
BLK_VERIFY_HALT);
zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
data, size, size, done, private,
ZIO_TYPE_READ, priority, flags, NULL, 0, zb,