From: Liu Bo Date: Sat, 25 Aug 2018 05:47:09 +0000 (+0800) Subject: Btrfs: set leave_spinning in btrfs_get_extent X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=e49aabd973fd0b3e8e949bd9e7e05acbb9008244;p=openwrt%2Fstaging%2Fblogic.git Btrfs: set leave_spinning in btrfs_get_extent Unless it's going to read inline extents from btree leaf to page, btrfs_get_extent won't sleep during the period of holding path lock. This sets leave_spinning at first and sets path to blocking mode right before reading inline extent if that's the case. The benefit is that a path in spinning mode typically has lower impact (faster) on waiters rather than that in the blocking mode. Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 80e92c4448bb..e8a954c47f65 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6827,6 +6827,12 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, /* Chances are we'll be called again, so go ahead and do readahead */ path->reada = READA_FORWARD; + /* + * Unless we're going to uncompress the inline extent, no sleep would + * happen. + */ + path->leave_spinning = 1; + ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0); if (ret < 0) { err = ret; @@ -6929,6 +6935,8 @@ next: em->orig_block_len = em->len; em->orig_start = em->start; ptr = btrfs_file_extent_inline_start(item) + extent_offset; + + btrfs_set_path_blocking(path); if (!PageUptodate(page)) { if (btrfs_file_extent_compression(leaf, item) != BTRFS_COMPRESS_NONE) {