This is a patch to fix the bsg hang bug reported by Pete: http://marc.info/?t=121182152200003&r=1&w=2 == From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Subject: [PATCH] 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@xxxxxxx> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- block/bsg.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-) diff --git a/block/bsg.c b/block/bsg.c index f0b7cd3..7cdec32 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); -- 1.5.3.6 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
