btrfs: fix comment about nbytes increase at replay_one_extent()

The comment is wrong about the part where it says a prealloc extent does
not contribute to an inode's nbytes - it does. Only holes don't contribute
and that's what we are checking for, as prealloc extents always have a
disk_bytenr different from 0. So fix the comment and re-organize the code
to not set nbytes twice and set it to the extent item's number of bytes
only if it doesn't represent a hole - in case it's a hole we have already
initialized nbytes to 0 when we declared it.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 144b12725365062d5565a2503ab1ddd9f5f2bf2b..96492080fed85a0a6526911eaa8439dea12b5ea7 100644 (file)
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -740,15 +740,10 @@ static noinline int replay_one_extent(struct walk_control *wc)
 
        if (found_type == BTRFS_FILE_EXTENT_REG ||
            found_type == BTRFS_FILE_EXTENT_PREALLOC) {
-               nbytes = btrfs_file_extent_num_bytes(wc->log_leaf, item);
-               extent_end = start + nbytes;
-
-               /*
-                * We don't add to the inodes nbytes if we are prealloc or a
-                * hole.
-                */
-               if (btrfs_file_extent_disk_bytenr(wc->log_leaf, item) == 0)
-                       nbytes = 0;
+               extent_end = start + btrfs_file_extent_num_bytes(wc->log_leaf, item);
+               /* Holes don't take up space. */
+               if (btrfs_file_extent_disk_bytenr(wc->log_leaf, item) != 0)
+                       nbytes = btrfs_file_extent_num_bytes(wc->log_leaf, item);
        } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
                size = btrfs_file_extent_ram_bytes(wc->log_leaf, item);
                nbytes = btrfs_file_extent_ram_bytes(wc->log_leaf, item);