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authorMark Fasheh <mfasheh@suse.de>2016-03-31 03:57:48 +0300
committerDavid Sterba <dsterba@suse.com>2016-04-04 17:29:22 +0300
commit918c2ee103cf9956f1c61d3f848dbb49fd2d104a (patch)
treebe9e58da9801a1210acc6f4fec901eb1797acc17 /fs
parent0305bc279317a6ba261a663cc32721d78e6544cf (diff)
downloadlinux-918c2ee103cf9956f1c61d3f848dbb49fd2d104a.tar.xz
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/qgroup.c54
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: