From f098631848cd9f4142b6dec7ea95baad846e1670 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Wed, 20 Jun 2018 10:02:30 +0100 Subject: [PATCH] Btrfs: fix physical offset reported by fiemap for inline extents Commit 9d311e11fc1f ("Btrfs: fiemap: pass correct bytenr when fm_extent_count is zero") introduced a regression where we no longer report 0 as the physical offset for inline extents (and other extents with a special block_start value). This is because it always sets the variable used to report the physical offset ("disko") as em->block_start plus some offset, and em->block_start has the value 18446744073709551614 ((u64) -2) for inline extents. This made the btrfs test 004 (from fstests) often fail, for example, for a file with an inline extent we have the following items in the subvolume tree: item 101 key (418 INODE_ITEM 0) itemoff 11029 itemsize 160 generation 25 transid 38 size 1525 nbytes 1525 block group 0 mode 100666 links 1 uid 0 gid 0 rdev 0 sequence 0 flags 0x2(none) atime 1529342058.461891730 (2018-06-18 18:14:18) ctime 1529342058.461891730 (2018-06-18 18:14:18) mtime 1529342058.461891730 (2018-06-18 18:14:18) otime 1529342055.869892885 (2018-06-18 18:14:15) item 102 key (418 INODE_REF 264) itemoff 11016 itemsize 13 index 25 namelen 3 name: fc7 item 103 key (418 EXTENT_DATA 0) itemoff 9470 itemsize 1546 generation 38 type 0 (inline) inline extent data size 1525 ram_bytes 1525 compression 0 (none) Then when test 004 invoked fiemap against the file it got a non-zero physical offset: $ filefrag -v /mnt/p0/d4/d7/fc7 Filesystem type is: 9123683e File size of /mnt/p0/d4/d7/fc7 is 1525 (1 block of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 4095: 18446744073709551614.. 4093: 4096: last,not_aligned,inline,eof /mnt/p0/d4/d7/fc7: 1 extent found This resulted in the test failing like this: btrfs/004 49s ... [failed, exit status 1]- output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/004.out.bad) --- tests/btrfs/004.out 2016-08-23 10:17:35.027012095 +0100 +++ /home/fdmanana/git/hub/xfstests/results//btrfs/004.out.bad 2018-06-18 18:15:02.385872155 +0100 @@ -1,3 +1,10 @@ QA output created by 004 *** test backref walking -*** done +./tests/btrfs/004: line 227: [: 7.55578637259143e+22: integer expression expected +ERROR: 7.55578637259143e+22 is not a valid numeric value. +unexpected output from + /home/fdmanana/git/hub/btrfs-progs/btrfs inspect-internal logical-resolve -s 65536 -P 7.55578637259143e+22 /home/fdmanana/btrfs-tests/scratch_1 ... (Run 'diff -u tests/btrfs/004.out /home/fdmanana/git/hub/xfstests/results//btrfs/004.out.bad' to see the entire diff) Ran: btrfs/004 The large number in scientific notation reported as an invalid numeric value is the result from the filter passed to perl which multiplies the physical offset by the block size reported by fiemap. So fix this by ensuring the physical offset is always set to 0 when we are processing an extent with a special block_start value. Fixes: 9d311e11fc1f ("Btrfs: fiemap: pass correct bytenr when fm_extent_count is zero") Signed-off-by: Filipe Manana Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 8e4a7cdbc9f5..1aa91d57404a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4545,8 +4545,11 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, offset_in_extent = em_start - em->start; em_end = extent_map_end(em); em_len = em_end - em_start; - disko = em->block_start + offset_in_extent; flags = 0; + if (em->block_start < EXTENT_MAP_LAST_BYTE) + disko = em->block_start + offset_in_extent; + else + disko = 0; /* * bump off for our next call to get_extent -- 2.30.2