From 48180e15d3eaff51b1da30a90bc64b7acba8fb51 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= Date: Mon, 30 Mar 2020 18:48:42 +0200 Subject: fs: btrfs: support sparse extents MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When logical address of a regular extent is 0, the extent is sparse and consists of all zeros. Without this when sparse extents are used in a file reading fails with Cannot map logical address 0 to physical Signed-off-by: Marek Behún --- fs/btrfs/extent-io.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs') diff --git a/fs/btrfs/extent-io.c b/fs/btrfs/extent-io.c index 66d0e1c7d6..2e4599cf64 100644 --- a/fs/btrfs/extent-io.c +++ b/fs/btrfs/extent-io.c @@ -78,6 +78,12 @@ u64 btrfs_read_extent_reg(struct btrfs_path *path, if (size > dlen - offset) size = dlen - offset; + /* sparse extent */ + if (extent->disk_bytenr == 0) { + memset(out, 0, size); + return size; + } + physical = btrfs_map_logical_to_physical(extent->disk_bytenr); if (physical == -1ULL) return -1ULL; -- cgit v1.2.1