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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-05-28 18:56:55 -0400
committerJames Bottomley <James.Bottomley@HansenPartnership.com>2008-07-12 09:22:23 -0400
commit3f27e3ed11e67c5ee19d560a50eafd93cf8c6682 (patch)
treed2ed33ce7ca12c8b7e1c585ba9b2097095b0f89c /block
parent30e9ba9f2001f45960507f1963551311a67d0209 (diff)
[SCSI] bsg: fix bsg_mutex hang with device removal
We don't need to hold bsg_mutex during bsg_complete_all_commands(). It leads to a problem that we block bsg_unregister_queue during bsg_complete_all_commands (untill all the outstanding commands complete). Thanks to Pete Wyckoff for finding the bug and testing the patch. The detailed bug report is: http://marc.info/?l=linux-scsi&m=121182137132145&w=2 Tested-by: Pete Wyckoff <pw@osc.edu> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Diffstat (limited to 'block')
-rw-r--r--block/bsg.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/block/bsg.c b/block/bsg.c
index f0b7cd343216..7cdec32205d8 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -724,8 +724,13 @@ static int bsg_put_device(struct bsg_device *bd)
724 mutex_lock(&bsg_mutex); 724 mutex_lock(&bsg_mutex);
725 725
726 do_free = atomic_dec_and_test(&bd->ref_count); 726 do_free = atomic_dec_and_test(&bd->ref_count);
727 if (!do_free) 727 if (!do_free) {
728 mutex_unlock(&bsg_mutex);
728 goto out; 729 goto out;
730 }
731
732 hlist_del(&bd->dev_list);
733 mutex_unlock(&bsg_mutex);
729 734
730 dprintk("%s: tearing down\n", bd->name); 735 dprintk("%s: tearing down\n", bd->name);
731 736
@@ -741,10 +746,8 @@ static int bsg_put_device(struct bsg_device *bd)
741 */ 746 */
742 ret = bsg_complete_all_commands(bd); 747 ret = bsg_complete_all_commands(bd);
743 748
744 hlist_del(&bd->dev_list);
745 kfree(bd); 749 kfree(bd);
746out: 750out:
747 mutex_unlock(&bsg_mutex);
748 kref_put(&q->bsg_dev.ref, bsg_kref_release_function); 751 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
749 if (do_free) 752 if (do_free)
750 blk_put_queue(q); 753 blk_put_queue(q);