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authorMarek BehĂșn2020-03-30 18:48:42 +0200
committerTom Rini2020-04-20 12:23:29 -0400
commit48180e15d3eaff51b1da30a90bc64b7acba8fb51 (patch)
tree21b51f587ddac3a906c1329be9c97efb8742d0c6
parentf4a1426fd6e473ff523147a67d079c7ccb2a4e27 (diff)
fs: btrfs: support sparse extents
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 BehĂșn <marek.behun@nic.cz>
-rw-r--r--fs/btrfs/extent-io.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/btrfs/extent-io.c b/fs/btrfs/extent-io.c
index 66d0e1c7d65..2e4599cf64a 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;