v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_qm_bhv.c b/fs/xfs/xfs_qm_bhv.c
new file mode 100644
index 0000000..73a1d77
--- /dev/null
+++ b/fs/xfs/xfs_qm_bhv.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_quota.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_error.h"
+#include "xfs_trans.h"
+#include "xfs_qm.h"
+
+
+STATIC void
+xfs_fill_statvfs_from_dquot(
+ struct kstatfs *statp,
+ struct xfs_dquot *dqp)
+{
+ uint64_t limit;
+
+ limit = dqp->q_core.d_blk_softlimit ?
+ be64_to_cpu(dqp->q_core.d_blk_softlimit) :
+ be64_to_cpu(dqp->q_core.d_blk_hardlimit);
+ if (limit && statp->f_blocks > limit) {
+ statp->f_blocks = limit;
+ statp->f_bfree = statp->f_bavail =
+ (statp->f_blocks > dqp->q_res_bcount) ?
+ (statp->f_blocks - dqp->q_res_bcount) : 0;
+ }
+
+ limit = dqp->q_core.d_ino_softlimit ?
+ be64_to_cpu(dqp->q_core.d_ino_softlimit) :
+ be64_to_cpu(dqp->q_core.d_ino_hardlimit);
+ if (limit && statp->f_files > limit) {
+ statp->f_files = limit;
+ statp->f_ffree =
+ (statp->f_files > dqp->q_res_icount) ?
+ (statp->f_ffree - dqp->q_res_icount) : 0;
+ }
+}
+
+
+/*
+ * Directory tree accounting is implemented using project quotas, where
+ * the project identifier is inherited from parent directories.
+ * A statvfs (df, etc.) of a directory that is using project quota should
+ * return a statvfs of the project, not the entire filesystem.
+ * This makes such trees appear as if they are filesystems in themselves.
+ */
+void
+xfs_qm_statvfs(
+ xfs_inode_t *ip,
+ struct kstatfs *statp)
+{
+ xfs_mount_t *mp = ip->i_mount;
+ xfs_dquot_t *dqp;
+
+ if (!xfs_qm_dqget(mp, xfs_get_projid(ip), XFS_DQ_PROJ, false, &dqp)) {
+ xfs_fill_statvfs_from_dquot(statp, dqp);
+ xfs_qm_dqput(dqp);
+ }
+}
+
+int
+xfs_qm_newmount(
+ xfs_mount_t *mp,
+ uint *needquotamount,
+ uint *quotaflags)
+{
+ uint quotaondisk;
+ uint uquotaondisk = 0, gquotaondisk = 0, pquotaondisk = 0;
+
+ quotaondisk = xfs_sb_version_hasquota(&mp->m_sb) &&
+ (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT);
+
+ if (quotaondisk) {
+ uquotaondisk = mp->m_sb.sb_qflags & XFS_UQUOTA_ACCT;
+ pquotaondisk = mp->m_sb.sb_qflags & XFS_PQUOTA_ACCT;
+ gquotaondisk = mp->m_sb.sb_qflags & XFS_GQUOTA_ACCT;
+ }
+
+ /*
+ * If the device itself is read-only, we can't allow
+ * the user to change the state of quota on the mount -
+ * this would generate a transaction on the ro device,
+ * which would lead to an I/O error and shutdown
+ */
+
+ if (((uquotaondisk && !XFS_IS_UQUOTA_ON(mp)) ||
+ (!uquotaondisk && XFS_IS_UQUOTA_ON(mp)) ||
+ (gquotaondisk && !XFS_IS_GQUOTA_ON(mp)) ||
+ (!gquotaondisk && XFS_IS_GQUOTA_ON(mp)) ||
+ (pquotaondisk && !XFS_IS_PQUOTA_ON(mp)) ||
+ (!pquotaondisk && XFS_IS_PQUOTA_ON(mp))) &&
+ xfs_dev_is_read_only(mp, "changing quota state")) {
+ xfs_warn(mp, "please mount with%s%s%s%s.",
+ (!quotaondisk ? "out quota" : ""),
+ (uquotaondisk ? " usrquota" : ""),
+ (gquotaondisk ? " grpquota" : ""),
+ (pquotaondisk ? " prjquota" : ""));
+ return -EPERM;
+ }
+
+ if (XFS_IS_QUOTA_ON(mp) || quotaondisk) {
+ /*
+ * Call mount_quotas at this point only if we won't have to do
+ * a quotacheck.
+ */
+ if (quotaondisk && !XFS_QM_NEED_QUOTACHECK(mp)) {
+ /*
+ * If an error occurred, qm_mount_quotas code
+ * has already disabled quotas. So, just finish
+ * mounting, and get on with the boring life
+ * without disk quotas.
+ */
+ xfs_qm_mount_quotas(mp);
+ } else {
+ /*
+ * Clear the quota flags, but remember them. This
+ * is so that the quota code doesn't get invoked
+ * before we're ready. This can happen when an
+ * inode goes inactive and wants to free blocks,
+ * or via xfs_log_mount_finish.
+ */
+ *needquotamount = true;
+ *quotaflags = mp->m_qflags;
+ mp->m_qflags = 0;
+ }
+ }
+
+ return 0;
+}