xfs: don't count metadata directory files to quota

Files in the metadata directory tree are internal to the filesystem.
Don't count the inodes or the blocks they use in the root dquot because
users do not need to know about their resource usage.  This will also
quiet down complaints about dquot usage not matching du output.

Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

4 files changed, 23 insertions, 0 deletions

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index c1b211c260a9..3bf47458c517 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -983,6 +983,7 @@ xfs_qm_dqget_inode(
 
 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
 	ASSERT(xfs_inode_dquot(ip, type) == NULL);
+	ASSERT(!xfs_is_metadir_inode(ip));
 
 	id = xfs_qm_id_for_quotatype(ip, type);
 
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index d0674d84af3e..ec983cca9ada 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -304,6 +304,8 @@ xfs_qm_need_dqattach(
 		return false;
 	if (xfs_is_quota_inode(&mp->m_sb, ip->i_ino))
 		return false;
+	if (xfs_is_metadir_inode(ip))
+		return false;
 	return true;
 }
 
@@ -326,6 +328,7 @@ xfs_qm_dqattach_locked(
 		return 0;
 
 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
+	ASSERT(!xfs_is_metadir_inode(ip));
 
 	if (XFS_IS_UQUOTA_ON(mp) && !ip->i_udquot) {
 		error = xfs_qm_dqattach_one(ip, XFS_DQTYPE_USER,
@@ -1204,6 +1207,10 @@ xfs_qm_dqusage_adjust(
 		}
 	}
 
+	/* Metadata directory files are not accounted to user-visible quotas. */
+	if (xfs_is_metadir_inode(ip))
+		goto error0;
+
 	ASSERT(ip->i_delayed_blks == 0);
 
 	if (XFS_IS_REALTIME_INODE(ip)) {
@@ -1754,6 +1761,8 @@ xfs_qm_vop_dqalloc(
 	if (!XFS_IS_QUOTA_ON(mp))
 		return 0;
 
+	ASSERT(!xfs_is_metadir_inode(ip));
+
 	lockflags = XFS_ILOCK_EXCL;
 	xfs_ilock(ip, lockflags);
 
@@ -1883,6 +1892,7 @@ xfs_qm_vop_chown(
 
 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
 	ASSERT(XFS_IS_QUOTA_ON(ip->i_mount));
+	ASSERT(!xfs_is_metadir_inode(ip));
 
 	/* old dquot */
 	prevdq = *IO_olddq;
@@ -1970,6 +1980,7 @@ xfs_qm_vop_create_dqattach(
 		return;
 
 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
+	ASSERT(!xfs_is_metadir_inode(ip));
 
 	if (udqp && XFS_IS_UQUOTA_ON(mp)) {
 		ASSERT(ip->i_udquot == NULL);
diff --git a/fs/xfs/xfs_quota.h b/fs/xfs/xfs_quota.h
index 23d71a55bbc0..645761997bf2 100644
--- a/fs/xfs/xfs_quota.h
+++ b/fs/xfs/xfs_quota.h
@@ -29,6 +29,11 @@ struct xfs_buf;
 	 (XFS_IS_GQUOTA_ON(mp) && (ip)->i_gdquot == NULL) || \
 	 (XFS_IS_PQUOTA_ON(mp) && (ip)->i_pdquot == NULL))
 
+#define XFS_IS_DQDETACHED(ip) \
+	((ip)->i_udquot == NULL && \
+	 (ip)->i_gdquot == NULL && \
+	 (ip)->i_pdquot == NULL)
+
 #define XFS_QM_NEED_QUOTACHECK(mp) \
 	((XFS_IS_UQUOTA_ON(mp) && \
 		(mp->m_sb.sb_qflags & XFS_UQUOTA_CHKD) == 0) || \
diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
index b368e13424c4..ca7df018290e 100644
--- a/fs/xfs/xfs_trans_dquot.c
+++ b/fs/xfs/xfs_trans_dquot.c
@@ -156,6 +156,8 @@ xfs_trans_mod_ino_dquot(
 	unsigned int			field,
 	int64_t				delta)
 {
+	ASSERT(!xfs_is_metadir_inode(ip) || XFS_IS_DQDETACHED(ip));
+
 	xfs_trans_mod_dquot(tp, dqp, field, delta);
 
 	if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
@@ -247,6 +249,8 @@ xfs_trans_mod_dquot_byino(
 	    xfs_is_quota_inode(&mp->m_sb, ip->i_ino))
 		return;
 
+	ASSERT(!xfs_is_metadir_inode(ip) || XFS_IS_DQDETACHED(ip));
+
 	if (XFS_IS_UQUOTA_ON(mp) && ip->i_udquot)
 		xfs_trans_mod_ino_dquot(tp, ip, ip->i_udquot, field, delta);
 	if (XFS_IS_GQUOTA_ON(mp) && ip->i_gdquot)
@@ -962,6 +966,8 @@ xfs_trans_reserve_quota_nblks(
 
 	if (!XFS_IS_QUOTA_ON(mp))
 		return 0;
+	if (xfs_is_metadir_inode(ip))
+		return 0;
 
 	ASSERT(!xfs_is_quota_inode(&mp->m_sb, ip->i_ino));
 	xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);