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| author | Alasdair G Kergon <agk@redhat.com> | 2008-10-10 13:37:13 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2008-10-10 13:37:13 +0100 |
| commit | 0c2322e4ce144e130c03d813fe92de3798662c5e (patch) | |
| tree | a42eeb1a75d9e70a20a6d4d850064ba8292c2289 | |
| parent | 54160904260fa764ba6e2dc738770be30fdf9553 (diff) | |
| download | linux-3.10-0c2322e4ce144e130c03d813fe92de3798662c5e.tar.gz linux-3.10-0c2322e4ce144e130c03d813fe92de3798662c5e.tar.bz2 linux-3.10-0c2322e4ce144e130c03d813fe92de3798662c5e.zip | |
dm: detect lost queue
Detect and report buggy drivers that destroy their request_queue.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Stefan Raspl <raspl@linux.vnet.ibm.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | drivers/md/dm-table.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 5dd32b8a57a..a740a6950f5 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -482,6 +482,13 @@ void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); struct io_restrictions *rs = &ti->limits; + char b[BDEVNAME_SIZE]; + + if (unlikely(!q)) { + DMWARN("%s: Cannot set limits for nonexistent device %s", + dm_device_name(ti->table->md), bdevname(bdev, b)); + return; + } /* * Combine the device limits low. @@ -950,7 +957,14 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits) list_for_each_entry(dd, devices, list) { struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev); - r |= bdi_congested(&q->backing_dev_info, bdi_bits); + char b[BDEVNAME_SIZE]; + + if (likely(q)) + r |= bdi_congested(&q->backing_dev_info, bdi_bits); + else + DMWARN_LIMIT("%s: any_congested: nonexistent device %s", + dm_device_name(t->md), + bdevname(dd->dm_dev.bdev, b)); } return r; @@ -963,8 +977,14 @@ void dm_table_unplug_all(struct dm_table *t) list_for_each_entry(dd, devices, list) { struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev); - - blk_unplug(q); + char b[BDEVNAME_SIZE]; + + if (likely(q)) + blk_unplug(q); + else + DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s", + dm_device_name(t->md), + bdevname(dd->dm_dev.bdev, b)); } } |