[PATCH 2/3] Add quotactl_fd() support

[cem@kernel.org]

From: Carlos Maiolino <cem@kernel.org>

To be able to set quotas on filesystems without a backing device, quota tools
should be able to use quotactl_fd().
To achieve that, add a new helper, do_quotactl(), to select between quotactl()
and quotactl_fd().

This shouldn't change the semantics of current code. quotactl_fd() will be
called if and only if the handlers contain an empty device, and a valid
mountpoint.
All current calls containing a value device should be still handled by quotactl().
The same is true for calls passing a NULL device on purpose, aiming to sync
active quotas.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 Makefile.am       |  1 +
 quotacheck.c      | 12 +++++------
 quotaio.c         |  4 ++--
 quotaio_generic.c | 12 +++++------
 quotaio_meta.c    |  4 ++--
 quotaio_v1.c      | 10 ++++-----
 quotaio_v2.c      | 12 +++++------
 quotaio_xfs.c     | 21 ++++++++++--------
 quotaon.c         |  8 +++----
 quotaon_xfs.c     |  9 ++++----
 quotastats.c      |  4 ++--
 quotasync.c       |  2 +-
 quotasys.c        | 55 ++++++++++++++++++++++++++++++++++++-----------
 quotasys.h        |  3 +++
 14 files changed, 98 insertions(+), 59 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 372eafb..13a0f06 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -207,6 +207,7 @@ quotastats_SOURCES = \
 	pot.h
 
 quotastats_LDADD = \
+	libquota.a \
 	$(INTLLIBS)
 
 xqmstats_SOURCES = \
diff --git a/quotacheck.c b/quotacheck.c
index bd62d9a..e2c3bbd 100644
--- a/quotacheck.c
+++ b/quotacheck.c
@@ -648,8 +648,8 @@ Please turn quotas off or use -f to force checking.\n"),
 				    type2name(type), mnt->me_dir);
 		}
 		/* At least sync quotas so damage will be smaller */
-		if (quotactl(QCMD((kernel_iface == IFACE_GENERIC)? Q_SYNC : Q_6_5_SYNC, type),
-			     mnt->me_devname, 0, NULL) < 0)
+		if (do_quotactl(QCMD((kernel_iface == IFACE_GENERIC)? Q_SYNC : Q_6_5_SYNC, type),
+			     mnt->me_devname, mnt->me_dir, 0, NULL) < 0)
 			die(4, _("Error while syncing quotas on %s: %s\n"), mnt->me_devname, strerror(errno));
 	}
 
@@ -848,8 +848,8 @@ static int dump_to_file(struct mount_entry *mnt, int type)
 		if (get_qf_name(mnt, type, cfmt, NF_FORMAT, &filename) < 0)
 			errstr(_("Cannot find checked quota file for %ss on %s!\n"), _(type2name(type)), mnt->me_devname);
 		else {
-			if (quotactl(QCMD((kernel_iface == IFACE_GENERIC) ? Q_QUOTAOFF : Q_6_5_QUOTAOFF, type),
-				     mnt->me_devname, 0, NULL) < 0)
+			if (do_quotactl(QCMD((kernel_iface == IFACE_GENERIC) ? Q_QUOTAOFF : Q_6_5_QUOTAOFF, type),
+				     mnt->me_devname, mnt->me_dir, 0, NULL) < 0)
 				errstr(_("Cannot turn %s quotas off on %s: %s\nKernel won't know about changes quotacheck did.\n"),
 					_(type2name(type)), mnt->me_devname, strerror(errno));
 			else {
@@ -859,9 +859,9 @@ static int dump_to_file(struct mount_entry *mnt, int type)
 				rename_files(mnt, type);
 
 				if (kernel_iface == IFACE_GENERIC)
-					ret = quotactl(QCMD(Q_QUOTAON, type), mnt->me_devname, util2kernfmt(cfmt), filename);
+					ret = do_quotactl(QCMD(Q_QUOTAON, type), mnt->me_devname, mnt->me_dir, util2kernfmt(cfmt), filename);
 				else
-					ret = quotactl(QCMD(Q_6_5_QUOTAON, type), mnt->me_devname, 0, filename);
+					ret = do_quotactl(QCMD(Q_6_5_QUOTAON, type), mnt->me_devname, mnt->me_dir, 0, filename);
 				if (ret < 0)
 					errstr(_("Cannot turn %s quotas on on %s: %s\nKernel won't know about changes quotacheck did.\n"),
 						_(type2name(type)), mnt->me_devname, strerror(errno));
diff --git a/quotaio.c b/quotaio.c
index 94ae458..9bebb5e 100644
--- a/quotaio.c
+++ b/quotaio.c
@@ -140,8 +140,8 @@ struct quota_handle *init_io(struct mount_entry *mnt, int type, int fmt, int fla
 		if (QIO_ENABLED(h)) {	/* Kernel uses same file? */
 			unsigned int cmd =
 				(kernel_iface == IFACE_GENERIC) ? Q_SYNC : Q_6_5_SYNC;
-			if (quotactl(QCMD(cmd, h->qh_type), h->qh_quotadev,
-				     0, NULL) < 0) {
+			if (do_quotactl(QCMD(cmd, h->qh_type), h->qh_quotadev,
+				     h->qh_dir, 0,  NULL) < 0) {
 				die(4, _("Cannot sync quotas on device %s: %s\n"),
 				    h->qh_quotadev, strerror(errno));
 			}
diff --git a/quotaio_generic.c b/quotaio_generic.c
index 5b23955..3c95872 100644
--- a/quotaio_generic.c
+++ b/quotaio_generic.c
@@ -50,7 +50,7 @@ int vfs_get_info(struct quota_handle *h)
 {
 	struct if_dqinfo kinfo;
 
-	if (quotactl(QCMD(Q_GETINFO, h->qh_type), h->qh_quotadev, 0, (void *)&kinfo) < 0) {
+	if (do_quotactl(QCMD(Q_GETINFO, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kinfo) < 0) {
 		errstr(_("Cannot get info for %s quota file from kernel on %s: %s\n"), type2name(h->qh_type), h->qh_quotadev, strerror(errno));
 		return -1;
 	}
@@ -68,7 +68,7 @@ int vfs_set_info(struct quota_handle *h, int flags)
 	kinfo.dqi_igrace = h->qh_info.dqi_igrace;
 	kinfo.dqi_valid = flags;
 
-	if (quotactl(QCMD(Q_SETINFO, h->qh_type), h->qh_quotadev, 0, (void *)&kinfo) < 0) {
+	if (do_quotactl(QCMD(Q_SETINFO, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kinfo) < 0) {
 		errstr(_("Cannot set info for %s quota file from kernel on %s: %s\n"), type2name(h->qh_type), h->qh_quotadev, strerror(errno));
 		return -1;
 	}
@@ -80,7 +80,7 @@ int vfs_get_dquot(struct dquot *dquot)
 {
 	struct if_dqblk kdqblk;
 
-	if (quotactl(QCMD(Q_GETQUOTA, dquot->dq_h->qh_type), dquot->dq_h->qh_quotadev, dquot->dq_id, (void *)&kdqblk) < 0) {
+	if (do_quotactl(QCMD(Q_GETQUOTA, dquot->dq_h->qh_type), dquot->dq_h->qh_quotadev, dquot->dq_h->qh_dir, dquot->dq_id, (void *)&kdqblk) < 0) {
 		errstr(_("Cannot get quota for %s %d from kernel on %s: %s\n"), type2name(dquot->dq_h->qh_type), dquot->dq_id, dquot->dq_h->qh_quotadev, strerror(errno));
 		return -1;
 	}
@@ -95,7 +95,7 @@ int vfs_set_dquot(struct dquot *dquot, int flags)
 
 	generic_util2kerndqblk(&kdqblk, &dquot->dq_dqb);
 	kdqblk.dqb_valid = flags;
-	if (quotactl(QCMD(Q_SETQUOTA, dquot->dq_h->qh_type), dquot->dq_h->qh_quotadev, dquot->dq_id, (void *)&kdqblk) < 0) {
+	if (do_quotactl(QCMD(Q_SETQUOTA, dquot->dq_h->qh_type), dquot->dq_h->qh_quotadev, dquot->dq_h->qh_dir, dquot->dq_id, (void *)&kdqblk) < 0) {
 		errstr(_("Cannot set quota for %s %d from kernel on %s: %s\n"), type2name(dquot->dq_h->qh_type), dquot->dq_id, dquot->dq_h->qh_quotadev, strerror(errno));
 		return -1;
 	}
@@ -188,8 +188,8 @@ int vfs_scan_dquots(struct quota_handle *h,
 
 	dquot->dq_h = h;
 	while (1) {
-		ret = quotactl(QCMD(Q_GETNEXTQUOTA, h->qh_type),
-			       h->qh_quotadev, id, (void *)&kdqblk);
+		ret = do_quotactl(QCMD(Q_GETNEXTQUOTA, h->qh_type),
+			       h->qh_quotadev, h->qh_dir, id, (void *)&kdqblk);
 		if (ret < 0)
 			break;
 
diff --git a/quotaio_meta.c b/quotaio_meta.c
index ad6ff7a..51ebbcf 100644
--- a/quotaio_meta.c
+++ b/quotaio_meta.c
@@ -59,8 +59,8 @@ static int meta_scan_dquots(struct quota_handle *h, int (*process_dquot)(struct
 	struct if_nextdqblk kdqblk;
 	int ret;
 
-	ret = quotactl(QCMD(Q_GETNEXTQUOTA, h->qh_type), h->qh_quotadev, 0,
-		       (void *)&kdqblk);
+	ret = do_quotactl(QCMD(Q_GETNEXTQUOTA, h->qh_type), h->qh_quotadev,
+			  h->qh_dir, 0, (void *)&kdqblk);
 	/*
 	 * Fall back to scanning using passwd if Q_GETNEXTQUOTA is not
 	 * supported
diff --git a/quotaio_v1.c b/quotaio_v1.c
index 6a6dc78..187a5a5 100644
--- a/quotaio_v1.c
+++ b/quotaio_v1.c
@@ -118,7 +118,7 @@ static int v1_init_io(struct quota_handle *h)
 		else {
 			struct v1_kern_dqblk kdqblk;
 
-			if (quotactl(QCMD(Q_V1_GETQUOTA, h->qh_type), h->qh_quotadev, 0, (void *)&kdqblk) < 0) {
+			if (do_quotactl(QCMD(Q_V1_GETQUOTA, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kdqblk) < 0) {
 				if (errno == EPERM) {	/* We have no permission to get this information? */
 					h->qh_info.dqi_bgrace = h->qh_info.dqi_igrace = 0;	/* It hopefully won't be needed */
 				}
@@ -193,11 +193,11 @@ static int v1_write_info(struct quota_handle *h)
 		else {
 			struct v1_kern_dqblk kdqblk;
 
-			if (quotactl(QCMD(Q_V1_GETQUOTA, h->qh_type), h->qh_quotadev, 0, (void *)&kdqblk) < 0)
+			if (do_quotactl(QCMD(Q_V1_GETQUOTA, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kdqblk) < 0)
 				return -1;
 			kdqblk.dqb_btime = h->qh_info.dqi_bgrace;
 			kdqblk.dqb_itime = h->qh_info.dqi_igrace;
-			if (quotactl(QCMD(Q_V1_SETQUOTA, h->qh_type), h->qh_quotadev, 0, (void *)&kdqblk) < 0)
+			if (do_quotactl(QCMD(Q_V1_SETQUOTA, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kdqblk) < 0)
 				return -1;
 		}
 	}
@@ -237,7 +237,7 @@ static struct dquot *v1_read_dquot(struct quota_handle *h, qid_t id)
 		else {
 			struct v1_kern_dqblk kdqblk;
 
-			if (quotactl(QCMD(Q_V1_GETQUOTA, h->qh_type), h->qh_quotadev, id, (void *)&kdqblk) < 0) {
+			if (do_quotactl(QCMD(Q_V1_GETQUOTA, h->qh_type), h->qh_quotadev, h->qh_dir, id, (void *)&kdqblk) < 0) {
 				free(dquot);
 				return NULL;
 			}
@@ -299,7 +299,7 @@ static int v1_commit_dquot(struct dquot *dquot, int flags)
 			else
 				cmd = Q_V1_SETQUOTA;
 			v1_util2kerndqblk(&kdqblk, &dquot->dq_dqb);
-			if (quotactl(QCMD(cmd, h->qh_type), h->qh_quotadev, dquot->dq_id,
+			if (do_quotactl(QCMD(cmd, h->qh_type), h->qh_quotadev, h->qh_dir, dquot->dq_id,
 			     (void *)&kdqblk) < 0)
 				return -1;
 		}
diff --git a/quotaio_v2.c b/quotaio_v2.c
index 56a549f..b0fe7bf 100644
--- a/quotaio_v2.c
+++ b/quotaio_v2.c
@@ -275,7 +275,7 @@ static int v2_init_io(struct quota_handle *h)
 		else {
 			struct v2_kern_dqinfo kdqinfo;
 
-			if (quotactl(QCMD(Q_V2_GETINFO, h->qh_type), h->qh_quotadev, 0, (void *)&kdqinfo) < 0) {
+			if (do_quotactl(QCMD(Q_V2_GETINFO, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kdqinfo) < 0) {
 				/* Temporary check just before fix gets to kernel */
 				if (errno == EPERM)	/* Don't have permission to get information? */
 					return 0;
@@ -403,8 +403,8 @@ static int v2_write_info(struct quota_handle *h)
 			kdqinfo.dqi_blocks = h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks;
 			kdqinfo.dqi_free_blk = h->qh_info.u.v2_mdqi.dqi_qtree.dqi_free_blk;
 			kdqinfo.dqi_free_entry = h->qh_info.u.v2_mdqi.dqi_qtree.dqi_free_entry;
-			if (quotactl(QCMD(Q_V2_SETGRACE, h->qh_type), h->qh_quotadev, 0, (void *)&kdqinfo) < 0 ||
-			    quotactl(QCMD(Q_V2_SETFLAGS, h->qh_type), h->qh_quotadev, 0, (void *)&kdqinfo) < 0)
+			if (do_quotactl(QCMD(Q_V2_SETGRACE, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kdqinfo) < 0 ||
+			    do_quotactl(QCMD(Q_V2_SETFLAGS, h->qh_type), h->qh_quotadev, h->qh_dir, 0, (void *)&kdqinfo) < 0)
 					return -1;
 		}
 	}
@@ -441,7 +441,7 @@ static struct dquot *v2_read_dquot(struct quota_handle *h, qid_t id)
 		else {
 			struct v2_kern_dqblk kdqblk;
 
-			if (quotactl(QCMD(Q_V2_GETQUOTA, h->qh_type), h->qh_quotadev, id, (void *)&kdqblk) < 0) {
+			if (do_quotactl(QCMD(Q_V2_GETQUOTA, h->qh_type), h->qh_quotadev, h->qh_dir, id, (void *)&kdqblk) < 0) {
 				free(dquot);
 				return NULL;
 			}
@@ -485,8 +485,8 @@ static int v2_commit_dquot(struct dquot *dquot, int flags)
 			else
 				cmd = Q_V2_SETQUOTA;
 			v2_util2kerndqblk(&kdqblk, &dquot->dq_dqb);
-			if (quotactl(QCMD(cmd, dquot->dq_h->qh_type), dquot->dq_h->qh_quotadev,
-			     dquot->dq_id, (void *)&kdqblk) < 0)
+			if (do_quotactl(QCMD(cmd, dquot->dq_h->qh_type), dquot->dq_h->qh_quotadev,
+			     dquot->dq_h->qh_dir, dquot->dq_id, (void *)&kdqblk) < 0)
 				return -1;
 		}
 		return 0;
diff --git a/quotaio_xfs.c b/quotaio_xfs.c
index 5abb2c2..0bf6f34 100644
--- a/quotaio_xfs.c
+++ b/quotaio_xfs.c
@@ -128,7 +128,7 @@ static int xfs_init_io(struct quota_handle *h)
 
 	qcmd = QCMD(Q_XFS_GETQSTAT, h->qh_type);
 	memset(&info, 0, sizeof(struct xfs_mem_dqinfo));
-	if (quotactl(qcmd, h->qh_quotadev, 0, (void *)&info) < 0)
+	if (do_quotactl(qcmd, h->qh_quotadev, h->qh_dir, 0, (void *)&info) < 0)
 		return -1;
 	h->qh_info.dqi_bgrace = info.qs_btimelimit;
 	h->qh_info.dqi_igrace = info.qs_itimelimit;
@@ -153,7 +153,7 @@ static int xfs_write_info(struct quota_handle *h)
 	xdqblk.d_itimer = h->qh_info.dqi_igrace;
 	xdqblk.d_fieldmask |= FS_DQ_TIMER_MASK;
 	qcmd = QCMD(Q_XFS_SETQLIM, h->qh_type);
-	if (quotactl(qcmd, h->qh_quotadev, 0, (void *)&xdqblk) < 0)
+	if (do_quotactl(qcmd, h->qh_quotadev, h->qh_dir, 0, (void *)&xdqblk) < 0)
 		return -1;
 	return 0;
 }
@@ -174,7 +174,8 @@ static struct dquot *xfs_read_dquot(struct quota_handle *h, qid_t id)
 		return dquot;
 
 	qcmd = QCMD(Q_XFS_GETQUOTA, h->qh_type);
-	if (quotactl(qcmd, h->qh_quotadev, id, (void *)&xdqblk) < 0) {
+	if (do_quotactl(qcmd, h->qh_quotadev, h->qh_dir,
+			id, (void *)&xdqblk) < 0) {
 		;
 	}
 	else {
@@ -219,7 +220,7 @@ static int xfs_commit_dquot(struct dquot *dquot, int flags)
 	}
 
 	qcmd = QCMD(Q_XFS_SETQLIM, h->qh_type);
-	if (quotactl(qcmd, h->qh_quotadev, id, (void *)&xdqblk) < 0)
+	if (do_quotactl(qcmd, h->qh_quotadev, h->qh_dir, id, (void *)&xdqblk) < 0)
 		return -1;
 	return 0;
 }
@@ -234,7 +235,9 @@ static int xfs_get_dquot(struct dquot *dq)
 	int ret;
 
 	memset(&d, 0, sizeof(d));
-	ret = quotactl(qcmd, dq->dq_h->qh_quotadev, dq->dq_id, (void *)&d);
+	ret = do_quotactl(qcmd, dq->dq_h->qh_quotadev, dq->dq_h->qh_dir,
+			  dq->dq_id, (void *)&d);
+
 	if (ret < 0) {
 		if (errno == ENOENT)
 			return 0;
@@ -254,8 +257,8 @@ static int xfs_kernel_scan_dquots(struct quota_handle *h,
 
 	dquot->dq_h = h;
 	while (1) {
-		ret = quotactl(QCMD(Q_XGETNEXTQUOTA, h->qh_type),
-			       h->qh_quotadev, id, (void *)&xdqblk);
+		ret = do_quotactl(QCMD(Q_XGETNEXTQUOTA, h->qh_type),
+			       h->qh_quotadev, h->qh_dir, id, (void *)&xdqblk);
 		if (ret < 0)
 			break;
 
@@ -286,8 +289,8 @@ static int xfs_scan_dquots(struct quota_handle *h, int (*process_dquot) (struct
 	int ret;
 	struct xfs_kern_dqblk xdqblk;
 
-	ret = quotactl(QCMD(Q_XGETNEXTQUOTA, h->qh_type), h->qh_quotadev, 0,
-		       (void *)&xdqblk);
+	ret = do_quotactl(QCMD(Q_XGETNEXTQUOTA, h->qh_type), h->qh_quotadev,
+			  h->qh_dir, 0, (void *)&xdqblk);
 	if (ret < 0 && (errno == ENOSYS || errno == EINVAL)) {
 		if (!XFS_USRQUOTA(h) && !XFS_GRPQUOTA(h) && !XFS_PRJQUOTA(h))
 			return 0;
diff --git a/quotaon.c b/quotaon.c
index 125b934..351c851 100644
--- a/quotaon.c
+++ b/quotaon.c
@@ -152,13 +152,13 @@ static int quotarsquashonoff(const char *quotadev, int type, int flags)
 
 		info.dqi_flags = V1_DQF_RSQUASH;
 		info.dqi_valid = IIF_FLAGS;
-		ret = quotactl(qcmd, quotadev, 0, (void *)&info);
+		ret = do_quotactl(qcmd, quotadev, NULL, 0, (void *)&info);
 	}
 	else {
 		int mode = (flags & STATEFLAG_OFF) ? 0 : 1;
 		int qcmd = QCMD(Q_V1_RSQUASH, type);
 
-		ret = quotactl(qcmd, quotadev, 0, (void *)&mode);
+		ret = do_quotactl(qcmd, quotadev, NULL, 0, (void *)&mode);
 	}
 	if (ret < 0) {
 		errstr(_("set root_squash on %s: %s\n"), quotadev, strerror(errno));
@@ -184,7 +184,7 @@ static int quotaonoff(const char *quotadev, const char *quotadir, char *quotafil
 			qcmd = QCMD(Q_QUOTAOFF, type);
 		else
 			qcmd = QCMD(Q_6_5_QUOTAOFF, type);
-		if (quotactl(qcmd, quotadev, 0, NULL) < 0) {
+		if (do_quotactl(qcmd, quotadev, quotadir, 0, NULL) < 0) {
 			errstr(_("quotactl on %s [%s]: %s\n"), quotadev, quotadir, strerror(errno));
 			return 1;
 		}
@@ -199,7 +199,7 @@ static int quotaonoff(const char *quotadev, const char *quotadir, char *quotafil
 		qcmd = QCMD(Q_6_5_QUOTAON, type);
 		kqf = 0;
 	}
-	if (quotactl(qcmd, quotadev, kqf, (void *)quotafile) < 0) {
+	if (do_quotactl(qcmd, quotadev, quotadir, kqf, (void *)quotafile) < 0) {
 		if (errno == ENOENT)
 			errstr(_("cannot find %s on %s [%s]\n"), quotafile, quotadev, quotadir);
 		else
diff --git a/quotaon_xfs.c b/quotaon_xfs.c
index d137240..dda3023 100644
--- a/quotaon_xfs.c
+++ b/quotaon_xfs.c
@@ -32,7 +32,7 @@ static int xfs_state_check(int qcmd, int type, int flags, const char *dev, int r
 	if (flags & STATEFLAG_ALL)
 		return 0;	/* noop */
 
-	if (quotactl(QCMD(Q_XFS_GETQSTAT, type), dev, 0, (void *)&info) < 0) {
+	if (do_quotactl(QCMD(Q_XFS_GETQSTAT, type), dev, NULL, 0, (void *)&info) < 0) {
 		errstr(_("quotactl() on %s: %s\n"), dev, strerror(errno));
 		return -1;
 	}
@@ -156,7 +156,7 @@ static int xfs_onoff(const char *dev, int type, int flags, int roothack, int xop
 	if (check != 1)
 		return (check < 0);
 
-	if (quotactl(QCMD(qcmd, type), dev, 0, (void *)&xopts) < 0) {
+	if (do_quotactl(QCMD(qcmd, type), dev, NULL, 0, (void *)&xopts) < 0) {
 		errstr(_("quotactl on %s: %s\n"), dev, strerror(errno));
 		return 1;
 	}
@@ -176,7 +176,7 @@ static int xfs_delete(const char *dev, int type, int flags, int roothack, int xo
 	if (check != 1)
 		return (check < 0);
 
-	if (quotactl(QCMD(qcmd, type), dev, 0, (void *)&xopts) < 0) {
+	if (do_quotactl(QCMD(qcmd, type), dev, NULL, 0, (void *)&xopts) < 0) {
 		errstr(_("Failed to delete quota: %s\n"),
 			strerror(errno));
 		return 1;
@@ -208,7 +208,8 @@ int xfs_newstate(struct mount_entry *mnt, int type, char *xarg, int flags)
 		struct xfs_mem_dqinfo info;
 		u_int16_t sbflags = 0;
 
-		if (!quotactl(QCMD(Q_XFS_GETQSTAT, type), mnt->me_devname, 0, (void *)&info))
+		if (!quotactl(QCMD(Q_XFS_GETQSTAT, type), mnt->me_devname,
+			      mnt->me_dir, 0, (void *)&info))
 			sbflags = (info.qs_flags & 0xff00) >> 8;
 
 		if ((type == USRQUOTA && (sbflags & XFS_QUOTA_UDQ_ACCT)) &&
diff --git a/quotastats.c b/quotastats.c
index a059812..ee23afd 100644
--- a/quotastats.c
+++ b/quotastats.c
@@ -72,7 +72,7 @@ static int get_stats(struct util_dqstats *dqstats)
 		dqstats->free_dquots = get_proc_num("free_dquots");
 		dqstats->syncs = get_proc_num("syncs");
 	}
-	else if (quotactl(QCMD(Q_V1_GETSTATS, 0), NULL, 0, (caddr_t)&old_dqstats) >= 0) {
+	else if (do_quotactl(QCMD(Q_V1_GETSTATS, 0), NULL, NULL, 0, (caddr_t)&old_dqstats) >= 0) {
 		/* Structures are currently the same */
 		memcpy(dqstats, &old_dqstats, sizeof(old_dqstats));
 		dqstats->version = 0;
@@ -83,7 +83,7 @@ static int get_stats(struct util_dqstats *dqstats)
 			errstr(_("Error while getting quota statistics from kernel: %s\n"), strerror(errno));
 			goto out;
 		}
-		if (quotactl(QCMD(Q_V2_GETSTATS, 0), NULL, 0, (caddr_t)&v0_dqstats) < 0) {
+		if (do_quotactl(QCMD(Q_V2_GETSTATS, 0), NULL, NULL, 0, (caddr_t)&v0_dqstats) < 0) {
 			errstr(_("Error while getting old quota statistics from kernel: %s\n"), strerror(errno));
 			goto out;
 		}
diff --git a/quotasync.c b/quotasync.c
index 80f7e9e..cad2a20 100644
--- a/quotasync.c
+++ b/quotasync.c
@@ -100,7 +100,7 @@ static int sync_one(int type, char *dev)
 {
 	int qcmd = QCMD(Q_SYNC, type);
 
-	return quotactl(qcmd, dev, 0, NULL);
+	return do_quotactl(qcmd, dev, NULL, 0, NULL);
 }
 
 static int syncquotas(int type)
diff --git a/quotasys.c b/quotasys.c
index 9af9932..903816b 100644
--- a/quotasys.c
+++ b/quotasys.c
@@ -25,6 +25,7 @@
 #include <sys/vfs.h>
 #include <stdint.h>
 #include <sys/utsname.h>
+#include <sys/syscall.h>
 
 #include "pot.h"
 #include "bylabel.h"
@@ -670,6 +671,36 @@ const char *str2number(const char *string, qsize_t *inodes)
 	return NULL;
 }
 
+/*
+ * Wrappers for quotactl syscalls
+ */
+#ifdef SYS_quotactl_fd
+int do_quotactl(int cmd, const char *dev, const char *mnt, int id, caddr_t addr)
+{
+	int ret = -EINVAL;
+
+	if (mnt && !dev) {
+		int fd = open(mnt, O_DIRECTORY | O_PATH);
+
+		if (fd < 0) {
+			errstr(_("Unable to get a filedescriptor from mountpoint: %s\n"), mnt);
+			return fd;
+		}
+
+		ret = syscall(SYS_quotactl_fd, fd, cmd, id, addr);
+		close(fd);
+		return ret;
+	}
+
+	return quotactl(cmd, dev, id, addr);
+}
+#else
+int do_quotactl(int cmd, const char *dev, const char *mnt, int id, caddr_t addr)
+{
+	return quotactl(cmd, dev, id, addr);
+}
+#endif
+
 /*
  *	Wrappers for mount options processing functions
  */
@@ -685,7 +716,7 @@ static int hasxfsquota(const char *dev, struct mntent *mnt, int type, int flags)
 		return QF_XFS;
 
 	memset(&info, 0, sizeof(struct xfs_mem_dqinfo));
-	if (!quotactl(QCMD(Q_XFS_GETQSTAT, type), dev, 0, (void *)&info)) {
+	if (!do_quotactl(QCMD(Q_XFS_GETQSTAT, type), dev, mnt->mnt_dir, 0, (void *)&info)) {
 #ifdef XFS_ROOTHACK
 		int sbflags = (info.qs_flags & 0xff00) >> 8;
 #endif /* XFS_ROOTHACK */
@@ -719,7 +750,7 @@ static int hasvfsmetaquota(const char *dev, struct mntent *mnt, int type, int fl
 {
 	uint32_t fmt;
 
-	if (!quotactl(QCMD(Q_GETFMT, type), dev, 0, (void *)&fmt))
+	if (!do_quotactl(QCMD(Q_GETFMT, type), dev, mnt->mnt_dir, 0, (void *)&fmt))
 		return QF_META;
 	return QF_ERROR;
 }
@@ -796,7 +827,7 @@ static int hasquota(const char *dev, struct mntent *mnt, int type, int flags)
 	if (!strcmp(mnt->mnt_type, MNTTYPE_EXT4) || !strcmp(mnt->mnt_type, MNTTYPE_F2FS)) {
 		struct if_dqinfo kinfo;
 
-		if (quotactl(QCMD(Q_GETINFO, type), dev, 0, (void *)&kinfo) == 0) {
+		if (do_quotactl(QCMD(Q_GETINFO, type), dev, mnt->mnt_dir, 0, (void *)&kinfo) == 0) {
 			if (kinfo.dqi_flags & DQF_SYS_FILE)
 				return QF_META;
 		}
@@ -1069,11 +1100,11 @@ void init_kernel_interface(void)
 		else {
 			fs_quota_stat_t dummy;
 
-			if (!quotactl(QCMD(Q_XGETQSTAT, 0), "/dev/root", 0, (void *)&dummy) ||
+			if (!do_quotactl(QCMD(Q_XGETQSTAT, 0), "/dev/root", NULL, 0, (void *)&dummy) ||
 			    (errno != EINVAL && errno != ENOSYS))
 				kernel_qfmt[kernel_qfmt_num++] = QF_XFS;
 		}
-		if (quotactl(QCMD(Q_V2_GETSTATS, 0), NULL, 0, (void *)&v2_stats) >= 0) {
+		if (do_quotactl(QCMD(Q_V2_GETSTATS, 0), NULL, NULL, 0, (void *)&v2_stats) >= 0) {
 			kernel_qfmt[kernel_qfmt_num++] = QF_VFSV0;
 			kernel_iface = IFACE_VFSV0;
 		}
@@ -1085,9 +1116,9 @@ void init_kernel_interface(void)
 			int err_quota = 0;
  			char tmp[1024];         /* Just temporary buffer */
 
-			if (quotactl(QCMD(Q_V1_GETSTATS, 0), NULL, 0, tmp))
+			if (do_quotactl(QCMD(Q_V1_GETSTATS, 0), NULL, NULL, 0, tmp))
 				err_stat = errno;
-			if (quotactl(QCMD(Q_V1_GETQUOTA, 0), "/dev/null", 0, tmp))
+			if (do_quotactl(QCMD(Q_V1_GETQUOTA, 0), "/dev/null", NULL, 0, tmp))
 				err_quota = errno;
 
 			/* On a RedHat 2.4.2-2 	we expect 0, EINVAL
@@ -1127,7 +1158,7 @@ static int v1_kern_quota_on(const char *dev, int type)
 	char tmp[1024];		/* Just temporary buffer */
 	qid_t id = (type == USRQUOTA) ? getuid() : getgid();
 
-	if (!quotactl(QCMD(Q_V1_GETQUOTA, type), dev, id, tmp))	/* OK? */
+	if (!do_quotactl(QCMD(Q_V1_GETQUOTA, type), dev, NULL, id, tmp))	/* OK? */
 		return 1;
 	return 0;
 }
@@ -1138,7 +1169,7 @@ static int v2_kern_quota_on(const char *dev, int type)
 	char tmp[1024];		/* Just temporary buffer */
 	qid_t id = (type == USRQUOTA) ? getuid() : getgid();
 
-	if (!quotactl(QCMD(Q_V2_GETQUOTA, type), dev, id, tmp))	/* OK? */
+	if (!do_quotactl(QCMD(Q_V2_GETQUOTA, type), dev, NULL, id, tmp))	/* OK? */
 		return 1;
 	return 0;
 }
@@ -1155,7 +1186,7 @@ int kern_quota_state_xfs(const char *dev, int type)
 {
 	struct xfs_mem_dqinfo info;
 
-	if (!quotactl(QCMD(Q_XFS_GETQSTAT, type), dev, 0, (void *)&info)) {
+	if (!do_quotactl(QCMD(Q_XFS_GETQSTAT, type), dev, NULL, 0, (void *)&info)) {
 		if (type == USRQUOTA) {
 			return !!(info.qs_flags & XFS_QUOTA_UDQ_ACCT) +
 			       !!(info.qs_flags & XFS_QUOTA_UDQ_ENFD);
@@ -1199,8 +1230,8 @@ int kern_quota_on(struct mount_entry *mnt, int type, int fmt)
 	if (kernel_iface == IFACE_GENERIC) {
 		int actfmt;
 
-		if (quotactl(QCMD(Q_GETFMT, type), mnt->me_devname, 0,
-			     (void *)&actfmt) >= 0) {
+		if (do_quotactl(QCMD(Q_GETFMT, type), mnt->me_devname,
+				mnt->me_dir, 0, (void *)&actfmt) >= 0) {
 			actfmt = kern2utilfmt(actfmt);
 			if (actfmt >= 0)
 				return actfmt;
diff --git a/quotasys.h b/quotasys.h
index 841251e..b166ad2 100644
--- a/quotasys.h
+++ b/quotasys.h
@@ -206,6 +206,9 @@ void end_mounts_scan(void);
 /* Parse kernel version and return 1 if ext4 supports quota feature */
 int ext4_supports_quota_feature(void);
 
+/* Wrapper around quota syscalls, either call quotactl or quotactl_fd */
+int do_quotactl(int cmd, const char *dev, const char *mnt, int id, caddr_t addr);
+
 /* Quota output formats */
 #define QOF_ERROR	-1
 #define QOF_DEFAULT	0
-- 
2.43.0