[PATCH 6/8] Fix btrfs/098 to work on non-4k block sized filesystems

Chandan Rajendra
2015-11-30T10:17:36Z

This commit makes use of the new _filter_xfs_io_blocks_modified filtering
function to print information in terms of file blocks rather than file
offset.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
tests/btrfs/098 | 67 +++++++++++++++++++++++++++++------------------------
tests/btrfs/098.out | 27 ++++++++++++++++-----
2 files changed, 58 insertions(+), 36 deletions(-)

diff --git a/tests/btrfs/098 b/tests/btrfs/098
index 8aef119..49f6d16 100755
--- a/tests/btrfs/098
+++ b/tests/btrfs/098
@@ -58,43 +58,50 @@ _scratch_mkfs >>$seqres.full 2>&1
_init_flakey
_mount_flakey

-# Create our test file with a single 100K extent starting at file offset 800K.
-# We fsync the file here to make the fsync log tree gets a single csum item that
-# covers the whole 100K extent, which causes the second fsync, done after the
-# cloning operation below, to not leave in the log tree two csum items covering
-# two sub-ranges ([0, 20K[ and [20K, 100K[)) of our extent.
-$XFS_IO_PROG -f -c "pwrite -S 0xaa 800K 100K" \
+BLOCK_SIZE=$(get_block_size $SCRATCH_MNT)
+
+# Create our test file with a single 25 block extent starting at file offset
+# mapped by 200th block We fsync the file here to make the fsync log tree get a
+# single csum item that covers the whole 25 block extent, which causes the
+# second fsync, done after the cloning operation below, to not leave in the log
+# tree two csum items covering two block sub-ranges ([0, 5[ and [5, 25[)) of our
+# extent.
+$XFS_IO_PROG -f -c "pwrite -S 0xaa $((200 * $BLOCK_SIZE)) $((25 * $BLOCK_SIZE))" \
-c "fsync" \
- $SCRATCH_MNT/foo | _filter_xfs_io
+ $SCRATCH_MNT/foo | _filter_xfs_io_blocks_modified
+

-# Now clone part of our extent into file offset 400K. This adds a file extent
-# item to our inode's metadata that points to the 100K extent we created before,
-# using a data offset of 20K and a data length of 20K, so that it refers to
-# the sub-range [20K, 40K[ of our original extent.
-$CLONER_PROG -s $((800 * 1024 + 20 * 1024)) -d $((400 * 1024)) \
- -l $((20 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo
+# Now clone part of our extent into file offset mapped by 100th block. This adds
+# a file extent item to our inode's metadata that points to the 25 block extent
+# we created before, using a data offset of 5 blocks and a data length of 5
+# blocks, so that it refers to the block sub-range [5, 10[ of our original
+# extent.
+$CLONER_PROG -s $(((200 * $BLOCK_SIZE) + (5 * $BLOCK_SIZE))) \
+ -d $((100 * $BLOCK_SIZE)) -l $((5 * $BLOCK_SIZE)) \
+ $SCRATCH_MNT/foo $SCRATCH_MNT/foo

# Now fsync our file to make sure the extent cloning is durably persisted. This
# fsync will not add a second csum item to the log tree containing the checksums
-# for the blocks in the sub-range [20K, 40K[ of our extent, because there was
+# for the blocks in the block sub-range [5, 10[ of our extent, because there was
# already a csum item in the log tree covering the whole extent, added by the
# first fsync we did before.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

-echo "File digest before power failure:"
-md5sum $SCRATCH_MNT/foo | _filter_scratch
+echo "File contents before power failure:"
+od -t x1 $SCRATCH_MNT/foo | _filter_od

# The fsync log replay first processes the file extent item corresponding to the
-# file offset 400K (the one which refers to the [20K, 40K[ sub-range of our 100K
-# extent) and then processes the file extent item for file offset 800K. It used
-# to happen that when processing the later, it erroneously left in the csum tree
-# 2 csum items that overlapped each other, 1 for the sub-range [20K, 40K[ and 1
-# for the whole range of our extent. This introduced a problem where subsequent
-# lookups for the checksums of blocks within the range [40K, 100K[ of our extent
-# would not find anything because lookups in the csum tree ended up looking only
-# at the smaller csum item, the one covering the subrange [20K, 40K[. This made
-# read requests assume an expected checksum with a value of 0 for those blocks,
-# which caused checksum verification failure when the read operations finished.
+# file offset mapped by 100th block (the one which refers to the [5, 10[ block
+# sub-range of our 25 block extent) and then processes the file extent item for
+# file offset mapped by 200th block. It used to happen that when processing the
+# later, it erroneously left in the csum tree 2 csum items that overlapped each
+# other, 1 for the block sub-range [5, 10[ and 1 for the whole range of our
+# extent. This introduced a problem where subsequent lookups for the checksums
+# of blocks within the block range [10, 25[ of our extent would not find
+# anything because lookups in the csum tree ended up looking only at the smaller
+# csum item, the one covering the block subrange [5, 10[. This made read
+# requests assume an expected checksum with a value of 0 for those blocks, which
+# caused checksum verification failure when the read operations finished.
# However those checksum failure did not result in read requests returning an
# error to user space (like -EIO for e.g.) because the expected checksum value
# had the special value 0, and in that case btrfs set all bytes of the
@@ -106,10 +113,10 @@ md5sum $SCRATCH_MNT/foo | _filter_scratch
#
_flakey_drop_and_remount

-echo "File digest after log replay:"
-# Must match the same digest he had after cloning the extent and before the
-# power failure happened.
-md5sum $SCRATCH_MNT/foo | _filter_scratch
+echo "File contents after log replay:"
+# Must match the file contents we had after cloning the extent and before
+# the power failure happened.
+od -t x1 $SCRATCH_MNT/foo | _filter_od

_unmount_flakey

diff --git a/tests/btrfs/098.out b/tests/btrfs/098.out
index 3aa0772..98a96de 100644
--- a/tests/btrfs/098.out
+++ b/tests/btrfs/098.out
@@ -1,7 +1,22 @@
QA output created by 098
-wrote 102400/102400 bytes at offset 819200
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-File digest before power failure:
-39b386375971248740ed8651d5a2ed9f SCRATCH_MNT/foo
-File digest after log replay:
-39b386375971248740ed8651d5a2ed9f SCRATCH_MNT/foo
+Blocks modified: [200 - 224]
+File contents before power failure:
+0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+*
+144 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
+*
+151 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+*
+310 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
+*
+341
+File contents after log replay:
+0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+*
+144 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
+*
+151 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+*
+310 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
+*
+341
--
2.1.0