| Message ID | 1526612424-97061-5-git-send-email-bo.liu@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2018年05月18日 11:00, Liu Bo wrote: > The check is superfluous since all of callers who set search_for_commit > also have skip_locking set. > > Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Although more obvious comment about search_commit_root and skip_locking in ctree.h will be much better. Thanks, Qu > --- > fs/btrfs/ctree.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c > index d12fc0474e21..8d3b09038f37 100644 > --- a/fs/btrfs/ctree.c > +++ b/fs/btrfs/ctree.c > @@ -2623,8 +2623,6 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, > level = btrfs_header_level(b); > if (p->need_commit_sem) > up_read(&fs_info->commit_root_sem); > - if (!p->skip_locking) > - btrfs_tree_read_lock(b); > > goto out; > } >
On Fri, May 18, 2018 at 01:27:50PM +0800, Qu Wenruo wrote: > > > On 2018年05月18日 11:00, Liu Bo wrote: > > The check is superfluous since all of callers who set search_for_commit > > also have skip_locking set. > > > > Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> > > Reviewed-by: Qu Wenruo <wqu@suse.com> > > Although more obvious comment about search_commit_root and skip_locking > in ctree.h will be much better. Not only a comment but also an ASSERT, this is too easy to get wrong. That all currenct callers do search_commit_root + skip_locking will not catch any future callers. And there was an example reported. -- 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 28.05.2018 17:21, David Sterba wrote: > On Fri, May 18, 2018 at 01:27:50PM +0800, Qu Wenruo wrote: >> >> >> On 2018年05月18日 11:00, Liu Bo wrote: >>> The check is superfluous since all of callers who set search_for_commit >>> also have skip_locking set. >>> >>> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> >> >> Reviewed-by: Qu Wenruo <wqu@suse.com> >> >> Although more obvious comment about search_commit_root and skip_locking >> in ctree.h will be much better. > > Not only a comment but also an ASSERT, this is too easy to get wrong. > That all currenct callers do search_commit_root + skip_locking will not > catch any future callers. And there was an example reported. How about my initial suggestion of setting skip)_locking in btrfs_search_slot if we see commit_root set? Let's try and make the life of callers as easier as possible. > -- > 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
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index d12fc0474e21..8d3b09038f37 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2623,8 +2623,6 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, level = btrfs_header_level(b); if (p->need_commit_sem) up_read(&fs_info->commit_root_sem); - if (!p->skip_locking) - btrfs_tree_read_lock(b); goto out; }
The check is superfluous since all of callers who set search_for_commit also have skip_locking set. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> --- fs/btrfs/ctree.c | 2 -- 1 file changed, 2 deletions(-)