| Message ID | 1e88615a596a6d811954832a744d105f94e42645.1603460665.git.josef@toxicpanda.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Block group caching fixes | expand |
On Fri, Oct 23, 2020 at 7:16 PM Josef Bacik <josef@toxicpanda.com> wrote: > > While fixing up our ->last_byte_to_unpin locking I noticed that we will > shorten len based on ->last_byte_to_unpin if we're caching when we're > adding back the free space. This is correct for the free space, as we > cannot unpin more than ->last_byte_to_unpin, however we use len to > adjust the ->bytes_pinned counters and such, which need to track the > actual pinned usage. This could result in > WARN_ON(space_info->bytes_pinned) triggering at unmount time. Fix this > by using a local variable for the amount to add to free space cache, and > leave len untouched in this case. > > Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Looks good, thanks. > --- > fs/btrfs/extent-tree.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 5fd60b13f4f8..a98f484a2fc1 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -2816,10 +2816,10 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, > len = cache->start + cache->length - start; > len = min(len, end + 1 - start); > > - if (start < cache->last_byte_to_unpin) { > - len = min(len, cache->last_byte_to_unpin - start); > - if (return_free_space) > - btrfs_add_free_space(cache, start, len); > + if (start < cache->last_byte_to_unpin && return_free_space) { > + u64 add_len = min(len, > + cache->last_byte_to_unpin - start); > + btrfs_add_free_space(cache, start, add_len); > } > > start += len; > -- > 2.26.2 >
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 5fd60b13f4f8..a98f484a2fc1 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2816,10 +2816,10 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, len = cache->start + cache->length - start; len = min(len, end + 1 - start); - if (start < cache->last_byte_to_unpin) { - len = min(len, cache->last_byte_to_unpin - start); - if (return_free_space) - btrfs_add_free_space(cache, start, len); + if (start < cache->last_byte_to_unpin && return_free_space) { + u64 add_len = min(len, + cache->last_byte_to_unpin - start); + btrfs_add_free_space(cache, start, add_len); } start += len;
While fixing up our ->last_byte_to_unpin locking I noticed that we will shorten len based on ->last_byte_to_unpin if we're caching when we're adding back the free space. This is correct for the free space, as we cannot unpin more than ->last_byte_to_unpin, however we use len to adjust the ->bytes_pinned counters and such, which need to track the actual pinned usage. This could result in WARN_ON(space_info->bytes_pinned) triggering at unmount time. Fix this by using a local variable for the amount to add to free space cache, and leave len untouched in this case. Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- fs/btrfs/extent-tree.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)