| Message ID | 1513165807-12261-1-git-send-email-nborisov@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Dec 13, 2017 at 01:50:07PM +0200, Nikolay Borisov wrote: > Commit e0ae99941423 ("btrfs: preallocate device flush bio") reworked > the way the flush bio is allocated and used. Concretely it allocates > the bio in __alloc_device and then re-uses it multiple times with a > very simple endio routine that just calls complete() without consuming > a reference. Allocated bios by default come with a ref count of 1, > which is then consumed by the endio routine (or not, in which case they > should be bio_put by the caller). The way the impleementation works now > is that the flush bio has a refcount of 2 and we only ever bio_put it > once, leaving it to hang indefinitely. Fix this by removing the extra > bio_get in __alloc_device. > Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Thanks, -liubo > Fixes: e0ae99941423 ("btrfs: preallocate device flush bio") > Signed-off-by: Nikolay Borisov <nborisov@suse.com> > --- > fs/btrfs/volumes.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 132966950f5f..3690822d469a 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -312,7 +312,6 @@ static struct btrfs_device *__alloc_device(void) > kfree(dev); > return ERR_PTR(-ENOMEM); > } > - bio_get(dev->flush_bio); > > INIT_LIST_HEAD(&dev->dev_list); > INIT_LIST_HEAD(&dev->dev_alloc_list); > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Dec 13, 2017 at 01:50:07PM +0200, Nikolay Borisov wrote: > Commit e0ae99941423 ("btrfs: preallocate device flush bio") reworked > the way the flush bio is allocated and used. Concretely it allocates > the bio in __alloc_device and then re-uses it multiple times with a > very simple endio routine that just calls complete() without consuming > a reference. Allocated bios by default come with a ref count of 1, > which is then consumed by the endio routine (or not, in which case they > should be bio_put by the caller). The way the impleementation works now > is that the flush bio has a refcount of 2 and we only ever bio_put it > once, leaving it to hang indefinitely. Fix this by removing the extra > bio_get in __alloc_device. > > Fixes: e0ae99941423 ("btrfs: preallocate device flush bio") Sigh, so many bugs. Hopefully that was the last one. > Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 132966950f5f..3690822d469a 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -312,7 +312,6 @@ static struct btrfs_device *__alloc_device(void) kfree(dev); return ERR_PTR(-ENOMEM); } - bio_get(dev->flush_bio); INIT_LIST_HEAD(&dev->dev_list); INIT_LIST_HEAD(&dev->dev_alloc_list);
Commit e0ae99941423 ("btrfs: preallocate device flush bio") reworked the way the flush bio is allocated and used. Concretely it allocates the bio in __alloc_device and then re-uses it multiple times with a very simple endio routine that just calls complete() without consuming a reference. Allocated bios by default come with a ref count of 1, which is then consumed by the endio routine (or not, in which case they should be bio_put by the caller). The way the impleementation works now is that the flush bio has a refcount of 2 and we only ever bio_put it once, leaving it to hang indefinitely. Fix this by removing the extra bio_get in __alloc_device. Fixes: e0ae99941423 ("btrfs: preallocate device flush bio") Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- fs/btrfs/volumes.c | 1 - 1 file changed, 1 deletion(-)