| #! /bin/bash |
| # SPDX-License-Identifier: GPL-2.0 |
| # Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved. |
| # |
| # FS QA Test No. 056 |
| # |
| # This test is motivated by an fsync issue discovered in btrfs. |
| # The issue was that we could lose file data, that was previously fsync'ed |
| # successfully, if we end up adding a hard link to our inode and then persist |
| # the fsync log later via an fsync of other inode for example. |
| # |
| # The btrfs issue was fixed by the following linux kernel patch: |
| # |
| # Btrfs: fix fsync data loss after adding hard link to inode |
| # |
| . ./common/preamble |
| _begin_fstest metadata auto quick log |
| |
| # Override the default cleanup function. |
| _cleanup() |
| { |
| _cleanup_flakey |
| rm -f $tmp.* |
| } |
| |
| # Import common functions. |
| . ./common/filter |
| . ./common/dmflakey |
| |
| # real QA test starts here |
| _supported_fs generic |
| _require_scratch |
| _require_hardlinks |
| _require_dm_target flakey |
| |
| _scratch_mkfs >> $seqres.full 2>&1 |
| _require_metadata_journaling $SCRATCH_DEV |
| _init_flakey |
| _mount_flakey |
| |
| # Create one file with data and fsync it. |
| # This made the btrfs fsync log persist the data and the inode metadata with |
| # a correct inode->i_size (4096 bytes). |
| $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ |
| $SCRATCH_MNT/foo | _filter_xfs_io |
| |
| # Now add one hard link to our file. This made the btrfs code update the fsync |
| # log, in memory only, with an inode metadata having a size of 0. |
| ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link |
| |
| # Now force persistence of the fsync log to disk, for example, by fsyncing some |
| # other file. |
| touch $SCRATCH_MNT/bar |
| $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar |
| |
| # Before a power loss or crash, we could read the 4Kb of data from our file as |
| # expected. |
| echo "File content before:" |
| od -t x1 $SCRATCH_MNT/foo |
| |
| _flakey_drop_and_remount |
| |
| # After the fsync log replay, because the fsync log had a value of 0 for our |
| # inode's i_size, we couldn't read anymore the 4Kb of data that we previously |
| # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. |
| echo "File content after:" |
| od -t x1 $SCRATCH_MNT/foo |
| |
| status=0 |
| exit |