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| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-05-29 07:56:55 +0900 |
|---|---|---|
| committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2008-07-12 08:22:23 -0500 |
| commit | 3f27e3ed11e67c5ee19d560a50eafd93cf8c6682 (patch) | |
| tree | d2ed33ce7ca12c8b7e1c585ba9b2097095b0f89c /block/bsg.c | |
| parent | 30e9ba9f2001f45960507f1963551311a67d0209 (diff) | |
| download | lwn-3f27e3ed11e67c5ee19d560a50eafd93cf8c6682.tar.gz lwn-3f27e3ed11e67c5ee19d560a50eafd93cf8c6682.zip | |
[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/bsg.c')
| -rw-r--r-- | block/bsg.c | 9 |
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) mutex_lock(&bsg_mutex); do_free = atomic_dec_and_test(&bd->ref_count); - if (!do_free) + if (!do_free) { + mutex_unlock(&bsg_mutex); goto out; + } + + hlist_del(&bd->dev_list); + mutex_unlock(&bsg_mutex); dprintk("%s: tearing down\n", bd->name); @@ -741,10 +746,8 @@ static int bsg_put_device(struct bsg_device *bd) */ ret = bsg_complete_all_commands(bd); - hlist_del(&bd->dev_list); kfree(bd); out: - mutex_unlock(&bsg_mutex); kref_put(&q->bsg_dev.ref, bsg_kref_release_function); if (do_free) blk_put_queue(q); |