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author | 2016-03-30 17:57:48 -0700 | |
---|---|---|
committer | 2016-04-04 16:29:22 +0200 | |
commit | 918c2ee103cf9956f1c61d3f848dbb49fd2d104a (patch) | |
tree | be9e58da9801a1210acc6f4fec901eb1797acc17 | |
parent | btrfs: Output more info for enospc_debug mount option (diff) | |
download | linux-918c2ee103cf9956f1c61d3f848dbb49fd2d104a.tar.gz linux-918c2ee103cf9956f1c61d3f848dbb49fd2d104a.tar.bz2 linux-918c2ee103cf9956f1c61d3f848dbb49fd2d104a.zip |
btrfs: handle non-fatal errors in btrfs_qgroup_inherit()
create_pending_snapshot() will go readonly on _any_ error return from
btrfs_qgroup_inherit(). If qgroups are enabled, a user can crash their fs by
just making a snapshot and asking it to inherit from an invalid qgroup. For
example:
$ btrfs sub snap -i 1/10 /btrfs/ /btrfs/foo
Will cause a transaction abort.
Fix this by only throwing errors in btrfs_qgroup_inherit() when we know
going readonly is acceptable.
The following xfstests test case reproduces this bug:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
here=`pwd`
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
cd /
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# remove previous $seqres.full before test
rm -f $seqres.full
# real QA test starts here
_supported_fs btrfs
_supported_os Linux
_require_scratch
rm -f $seqres.full
_scratch_mkfs
_scratch_mount
_run_btrfs_util_prog quota enable $SCRATCH_MNT
# The qgroup '1/10' does not exist and should be silently ignored
_run_btrfs_util_prog subvolume snapshot -i 1/10 $SCRATCH_MNT $SCRATCH_MNT/snap1
_scratch_unmount
echo "Silence is golden"
status=0
exit
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r-- | fs/btrfs/qgroup.c | 54 |
1 files changed, 32 insertions, 22 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 5279fdae7142..7173360eea7a 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1842,8 +1842,10 @@ out: } /* - * copy the acounting information between qgroups. This is necessary when a - * snapshot or a subvolume is created + * Copy the acounting information between qgroups. This is necessary + * when a snapshot or a subvolume is created. Throwing an error will + * cause a transaction abort so we take extra care here to only error + * when a readonly fs is a reasonable outcome. */ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid, @@ -1873,15 +1875,15 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, 2 * inherit->num_excl_copies; for (i = 0; i < nums; ++i) { srcgroup = find_qgroup_rb(fs_info, *i_qgroups); - if (!srcgroup) { - ret = -EINVAL; - goto out; - } - if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) { - ret = -EINVAL; - goto out; - } + /* + * Zero out invalid groups so we can ignore + * them later. + */ + if (!srcgroup || + ((srcgroup->qgroupid >> 48) <= (objectid >> 48))) + *i_qgroups = 0ULL; + ++i_qgroups; } } @@ -1916,17 +1918,19 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, */ if (inherit) { i_qgroups = (u64 *)(inherit + 1); - for (i = 0; i < inherit->num_qgroups; ++i) { + for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) { + if (*i_qgroups == 0) + continue; ret = add_qgroup_relation_item(trans, quota_root, objectid, *i_qgroups); - if (ret) + if (ret && ret != -EEXIST) goto out; ret = add_qgroup_relation_item(trans, quota_root, *i_qgroups, objectid); - if (ret) + if (ret && ret != -EEXIST) goto out; - ++i_qgroups; } + ret = 0; } @@ -1987,17 +1991,22 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, i_qgroups = (u64 *)(inherit + 1); for (i = 0; i < inherit->num_qgroups; ++i) { - ret = add_relation_rb(quota_root->fs_info, objectid, - *i_qgroups); - if (ret) - goto unlock; + if (*i_qgroups) { + ret = add_relation_rb(quota_root->fs_info, objectid, + *i_qgroups); + if (ret) + goto unlock; + } ++i_qgroups; } - for (i = 0; i < inherit->num_ref_copies; ++i) { + for (i = 0; i < inherit->num_ref_copies; ++i, i_qgroups += 2) { struct btrfs_qgroup *src; struct btrfs_qgroup *dst; + if (!i_qgroups[0] || !i_qgroups[1]) + continue; + src = find_qgroup_rb(fs_info, i_qgroups[0]); dst = find_qgroup_rb(fs_info, i_qgroups[1]); @@ -2008,12 +2017,14 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, dst->rfer = src->rfer - level_size; dst->rfer_cmpr = src->rfer_cmpr - level_size; - i_qgroups += 2; } - for (i = 0; i < inherit->num_excl_copies; ++i) { + for (i = 0; i < inherit->num_excl_copies; ++i, i_qgroups += 2) { struct btrfs_qgroup *src; struct btrfs_qgroup *dst; + if (!i_qgroups[0] || !i_qgroups[1]) + continue; + src = find_qgroup_rb(fs_info, i_qgroups[0]); dst = find_qgroup_rb(fs_info, i_qgroups[1]); @@ -2024,7 +2035,6 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, dst->excl = src->excl + level_size; dst->excl_cmpr = src->excl_cmpr + level_size; - i_qgroups += 2; } unlock: |