Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...

8 files changed, 253 insertions, 93 deletions

diff --git a/fs/quota/Makefile b/fs/quota/Makefile
index 5f9e9e276af0..c66c37cdaa39 100644
--- a/fs/quota/Makefile
+++ b/fs/quota/Makefile
@@ -2,6 +2,6 @@ obj-$(CONFIG_QUOTA)		+= dquot.o
 obj-$(CONFIG_QFMT_V1)		+= quota_v1.o
 obj-$(CONFIG_QFMT_V2)		+= quota_v2.o
 obj-$(CONFIG_QUOTA_TREE)	+= quota_tree.o
-obj-$(CONFIG_QUOTACTL)		+= quota.o
+obj-$(CONFIG_QUOTACTL)		+= quota.o kqid.o
 obj-$(CONFIG_QUOTACTL_COMPAT)	+= compat.o
 obj-$(CONFIG_QUOTA_NETLINK_INTERFACE)	+= netlink.o
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index c495a3055e2a..557a9c20a215 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -253,8 +253,10 @@ static qsize_t inode_get_rsv_space(struct inode *inode);
 static void __dquot_initialize(struct inode *inode, int type);
 
 static inline unsigned int
-hashfn(const struct super_block *sb, unsigned int id, int type)
+hashfn(const struct super_block *sb, struct kqid qid)
 {
+	unsigned int id = from_kqid(&init_user_ns, qid);
+	int type = qid.type;
 	unsigned long tmp;
 
 	tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
@@ -267,7 +269,7 @@ hashfn(const struct super_block *sb, unsigned int id, int type)
 static inline void insert_dquot_hash(struct dquot *dquot)
 {
 	struct hlist_head *head;
-	head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type);
+	head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id);
 	hlist_add_head(&dquot->dq_hash, head);
 }
 
@@ -277,15 +279,14 @@ static inline void remove_dquot_hash(struct dquot *dquot)
 }
 
 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
-				unsigned int id, int type)
+				struct kqid qid)
 {
 	struct hlist_node *node;
 	struct dquot *dquot;
 
 	hlist_for_each (node, dquot_hash+hashent) {
 		dquot = hlist_entry(node, struct dquot, dq_hash);
-		if (dquot->dq_sb == sb && dquot->dq_id == id &&
-		    dquot->dq_type == type)
+		if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid))
 			return dquot;
 	}
 	return NULL;
@@ -351,7 +352,7 @@ int dquot_mark_dquot_dirty(struct dquot *dquot)
 	spin_lock(&dq_list_lock);
 	if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) {
 		list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)->
-				info[dquot->dq_type].dqi_dirty_list);
+				info[dquot->dq_id.type].dqi_dirty_list);
 		ret = 0;
 	}
 	spin_unlock(&dq_list_lock);
@@ -410,17 +411,17 @@ int dquot_acquire(struct dquot *dquot)
 	mutex_lock(&dquot->dq_lock);
 	mutex_lock(&dqopt->dqio_mutex);
 	if (!test_bit(DQ_READ_B, &dquot->dq_flags))
-		ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
+		ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
 	if (ret < 0)
 		goto out_iolock;
 	set_bit(DQ_READ_B, &dquot->dq_flags);
 	/* Instantiate dquot if needed */
 	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
-		ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
+		ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
 		/* Write the info if needed */
-		if (info_dirty(&dqopt->info[dquot->dq_type])) {
-			ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
-						dquot->dq_sb, dquot->dq_type);
+		if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
+			ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
+					dquot->dq_sb, dquot->dq_id.type);
 		}
 		if (ret < 0)
 			goto out_iolock;
@@ -455,7 +456,7 @@ int dquot_commit(struct dquot *dquot)
 	/* Inactive dquot can be only if there was error during read/init
 	 * => we have better not writing it */
 	if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
-		ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot);
+		ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
 	else
 		ret = -EIO;
 out_sem:
@@ -477,12 +478,12 @@ int dquot_release(struct dquot *dquot)
 	if (atomic_read(&dquot->dq_count) > 1)
 		goto out_dqlock;
 	mutex_lock(&dqopt->dqio_mutex);
-	if (dqopt->ops[dquot->dq_type]->release_dqblk) {
-		ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
+	if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
+		ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
 		/* Write the info */
-		if (info_dirty(&dqopt->info[dquot->dq_type])) {
-			ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
-						dquot->dq_sb, dquot->dq_type);
+		if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
+			ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
+						dquot->dq_sb, dquot->dq_id.type);
 		}
 		if (ret >= 0)
 			ret = ret2;
@@ -521,7 +522,7 @@ restart:
 	list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
 		if (dquot->dq_sb != sb)
 			continue;
-		if (dquot->dq_type != type)
+		if (dquot->dq_id.type != type)
 			continue;
 		/* Wait for dquot users */
 		if (atomic_read(&dquot->dq_count)) {
@@ -741,7 +742,8 @@ void dqput(struct dquot *dquot)
 #ifdef CONFIG_QUOTA_DEBUG
 	if (!atomic_read(&dquot->dq_count)) {
 		quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
-			    quotatypes[dquot->dq_type], dquot->dq_id);
+			    quotatypes[dquot->dq_id.type],
+			    from_kqid(&init_user_ns, dquot->dq_id));
 		BUG();
 	}
 #endif
@@ -752,7 +754,7 @@ we_slept:
 		/* We have more than one user... nothing to do */
 		atomic_dec(&dquot->dq_count);
 		/* Releasing dquot during quotaoff phase? */
-		if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
+		if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) &&
 		    atomic_read(&dquot->dq_count) == 1)
 			wake_up(&dquot->dq_wait_unused);
 		spin_unlock(&dq_list_lock);
@@ -815,7 +817,7 @@ static struct dquot *get_empty_dquot(struct super_block *sb, int type)
 	INIT_LIST_HEAD(&dquot->dq_dirty);
 	init_waitqueue_head(&dquot->dq_wait_unused);
 	dquot->dq_sb = sb;
-	dquot->dq_type = type;
+	dquot->dq_id = make_kqid_invalid(type);
 	atomic_set(&dquot->dq_count, 1);
 
 	return dquot;
@@ -829,35 +831,35 @@ static struct dquot *get_empty_dquot(struct super_block *sb, int type)
  *   a) checking for quota flags under dq_list_lock and
  *   b) getting a reference to dquot before we release dq_list_lock
  */
-struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
+struct dquot *dqget(struct super_block *sb, struct kqid qid)
 {
-	unsigned int hashent = hashfn(sb, id, type);
+	unsigned int hashent = hashfn(sb, qid);
 	struct dquot *dquot = NULL, *empty = NULL;
 
-        if (!sb_has_quota_active(sb, type))
+        if (!sb_has_quota_active(sb, qid.type))
 		return NULL;
 we_slept:
 	spin_lock(&dq_list_lock);
 	spin_lock(&dq_state_lock);
-	if (!sb_has_quota_active(sb, type)) {
+	if (!sb_has_quota_active(sb, qid.type)) {
 		spin_unlock(&dq_state_lock);
 		spin_unlock(&dq_list_lock);
 		goto out;
 	}
 	spin_unlock(&dq_state_lock);
 
-	dquot = find_dquot(hashent, sb, id, type);
+	dquot = find_dquot(hashent, sb, qid);
 	if (!dquot) {
 		if (!empty) {
 			spin_unlock(&dq_list_lock);
-			empty = get_empty_dquot(sb, type);
+			empty = get_empty_dquot(sb, qid.type);
 			if (!empty)
 				schedule();	/* Try to wait for a moment... */
 			goto we_slept;
 		}
 		dquot = empty;
 		empty = NULL;
-		dquot->dq_id = id;
+		dquot->dq_id = qid;
 		/* all dquots go on the inuse_list */
 		put_inuse(dquot);
 		/* hash it first so it can be found */
@@ -1129,8 +1131,7 @@ static void dquot_decr_space(struct dquot *dquot, qsize_t number)
 
 struct dquot_warn {
 	struct super_block *w_sb;
-	qid_t w_dq_id;
-	short w_dq_type;
+	struct kqid w_dq_id;
 	short w_type;
 };
 
@@ -1154,11 +1155,11 @@ static int need_print_warning(struct dquot_warn *warn)
 	if (!flag_print_warnings)
 		return 0;
 
-	switch (warn->w_dq_type) {
+	switch (warn->w_dq_id.type) {
 		case USRQUOTA:
-			return current_fsuid() == warn->w_dq_id;
+			return uid_eq(current_fsuid(), warn->w_dq_id.uid);
 		case GRPQUOTA:
-			return in_group_p(warn->w_dq_id);
+			return in_group_p(warn->w_dq_id.gid);
 	}
 	return 0;
 }
@@ -1184,7 +1185,7 @@ static void print_warning(struct dquot_warn *warn)
 		tty_write_message(tty, ": warning, ");
 	else
 		tty_write_message(tty, ": write failed, ");
-	tty_write_message(tty, quotatypes[warn->w_dq_type]);
+	tty_write_message(tty, quotatypes[warn->w_dq_id.type]);
 	switch (warntype) {
 		case QUOTA_NL_IHARDWARN:
 			msg = " file limit reached.\r\n";
@@ -1218,7 +1219,6 @@ static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot,
 	warn->w_type = warntype;
 	warn->w_sb = dquot->dq_sb;
 	warn->w_dq_id = dquot->dq_id;
-	warn->w_dq_type = dquot->dq_type;
 }
 
 /*
@@ -1236,14 +1236,14 @@ static void flush_warnings(struct dquot_warn *warn)
 #ifdef CONFIG_PRINT_QUOTA_WARNING
 		print_warning(&warn[i]);
 #endif
-		quota_send_warning(warn[i].w_dq_type, warn[i].w_dq_id,
+		quota_send_warning(warn[i].w_dq_id,
 				   warn[i].w_sb->s_dev, warn[i].w_type);
 	}
 }
 
 static int ignore_hardlimit(struct dquot *dquot)
 {
-	struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
+	struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
 
 	return capable(CAP_SYS_RESOURCE) &&
 	       (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
@@ -1256,7 +1256,7 @@ static int check_idq(struct dquot *dquot, qsize_t inodes,
 {
 	qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
 
-	if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
+	if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) ||
 	    test_bit(DQ_FAKE_B, &dquot->dq_flags))
 		return 0;
 
@@ -1281,7 +1281,7 @@ static int check_idq(struct dquot *dquot, qsize_t inodes,
 	    dquot->dq_dqb.dqb_itime == 0) {
 		prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN);
 		dquot->dq_dqb.dqb_itime = get_seconds() +
-		    sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
+		    sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace;
 	}
 
 	return 0;
@@ -1294,7 +1294,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
 	qsize_t tspace;
 	struct super_block *sb = dquot->dq_sb;
 
-	if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
+	if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
 	    test_bit(DQ_FAKE_B, &dquot->dq_flags))
 		return 0;
 
@@ -1325,7 +1325,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc,
 		if (!prealloc) {
 			prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN);
 			dquot->dq_dqb.dqb_btime = get_seconds() +
-			    sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
+			    sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace;
 		}
 		else
 			/*
@@ -1344,7 +1344,7 @@ static int info_idq_free(struct dquot *dquot, qsize_t inodes)
 
 	if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
 	    dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
-	    !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
+	    !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type))
 		return QUOTA_NL_NOWARN;
 
 	newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
@@ -1390,7 +1390,6 @@ static int dquot_active(const struct inode *inode)
  */
 static void __dquot_initialize(struct inode *inode, int type)
 {
-	unsigned int id = 0;
 	int cnt;
 	struct dquot *got[MAXQUOTAS];
 	struct super_block *sb = inode->i_sb;
@@ -1403,18 +1402,19 @@ static void __dquot_initialize(struct inode *inode, int type)
 
 	/* First get references to structures we might need. */
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		struct kqid qid;
 		got[cnt] = NULL;
 		if (type != -1 && cnt != type)
 			continue;
 		switch (cnt) {
 		case USRQUOTA:
-			id = inode->i_uid;
+			qid = make_kqid_uid(inode->i_uid);
 			break;
 		case GRPQUOTA:
-			id = inode->i_gid;
+			qid = make_kqid_gid(inode->i_gid);
 			break;
 		}
-		got[cnt] = dqget(sb, id, cnt);
+		got[cnt] = dqget(sb, qid);
 	}
 
 	down_write(&sb_dqopt(sb)->dqptr_sem);
@@ -1897,10 +1897,10 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
 	if (!dquot_active(inode))
 		return 0;
 
-	if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid)
-		transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA);
-	if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)
-		transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA);
+	if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid))
+		transfer_to[USRQUOTA] = dqget(sb, make_kqid_uid(iattr->ia_uid));
+	if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))
+		transfer_to[GRPQUOTA] = dqget(sb, make_kqid_gid(iattr->ia_gid));
 
 	ret = __dquot_transfer(inode, transfer_to);
 	dqput_all(transfer_to);
@@ -2360,9 +2360,9 @@ static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
 
 	memset(di, 0, sizeof(*di));
 	di->d_version = FS_DQUOT_VERSION;
-	di->d_flags = dquot->dq_type == USRQUOTA ?
+	di->d_flags = dquot->dq_id.type == USRQUOTA ?
 			FS_USER_QUOTA : FS_GROUP_QUOTA;
-	di->d_id = dquot->dq_id;
+	di->d_id = from_kqid_munged(current_user_ns(), dquot->dq_id);
 
 	spin_lock(&dq_data_lock);
 	di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
@@ -2376,12 +2376,12 @@ static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
 	spin_unlock(&dq_data_lock);
 }
 
-int dquot_get_dqblk(struct super_block *sb, int type, qid_t id,
+int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
 		    struct fs_disk_quota *di)
 {
 	struct dquot *dquot;
 
-	dquot = dqget(sb, id, type);
+	dquot = dqget(sb, qid);
 	if (!dquot)
 		return -ESRCH;
 	do_get_dqblk(dquot, di);
@@ -2401,7 +2401,7 @@ static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
 {
 	struct mem_dqblk *dm = &dquot->dq_dqb;
 	int check_blim = 0, check_ilim = 0;
-	struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
+	struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type];
 
 	if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
 		return -EINVAL;
@@ -2488,13 +2488,13 @@ static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
 	return 0;
 }
 
-int dquot_set_dqblk(struct super_block *sb, int type, qid_t id,
+int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
 		  struct fs_disk_quota *di)
 {
 	struct dquot *dquot;
 	int rc;
 
-	dquot = dqget(sb, id, type);
+	dquot = dqget(sb, qid);
 	if (!dquot) {
 		rc = -ESRCH;
 		goto out;
diff --git a/fs/quota/kqid.c b/fs/quota/kqid.c
new file mode 100644
index 000000000000..2f97b0e2c501
--- /dev/null
+++ b/fs/quota/kqid.c
@@ -0,0 +1,132 @@
+#include <linux/fs.h>
+#include <linux/quota.h>
+#include <linux/export.h>
+
+/**
+ *	qid_eq - Test to see if to kquid values are the same
+ *	@left: A qid value
+ *	@right: Another quid value
+ *
+ *	Return true if the two qid values are equal and false otherwise.
+ */
+bool qid_eq(struct kqid left, struct kqid right)
+{
+	if (left.type != right.type)
+		return false;
+	switch(left.type) {
+	case USRQUOTA:
+		return uid_eq(left.uid, right.uid);
+	case GRPQUOTA:
+		return gid_eq(left.gid, right.gid);
+	case PRJQUOTA:
+		return projid_eq(left.projid, right.projid);
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(qid_eq);
+
+/**
+ *	qid_lt - Test to see if one qid value is less than another
+ *	@left: The possibly lesser qid value
+ *	@right: The possibly greater qid value
+ *
+ *	Return true if left is less than right and false otherwise.
+ */
+bool qid_lt(struct kqid left, struct kqid right)
+{
+	if (left.type < right.type)
+		return true;
+	if (left.type > right.type)
+		return false;
+	switch (left.type) {
+	case USRQUOTA:
+		return uid_lt(left.uid, right.uid);
+	case GRPQUOTA:
+		return gid_lt(left.gid, right.gid);
+	case PRJQUOTA:
+		return projid_lt(left.projid, right.projid);
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(qid_lt);
+
+/**
+ *	from_kqid - Create a qid from a kqid user-namespace pair.
+ *	@targ: The user namespace we want a qid in.
+ *	@kuid: The kernel internal quota identifier to start with.
+ *
+ *	Map @kqid into the user-namespace specified by @targ and
+ *	return the resulting qid.
+ *
+ *	There is always a mapping into the initial user_namespace.
+ *
+ *	If @kqid has no mapping in @targ (qid_t)-1 is returned.
+ */
+qid_t from_kqid(struct user_namespace *targ, struct kqid kqid)
+{
+	switch (kqid.type) {
+	case USRQUOTA:
+		return from_kuid(targ, kqid.uid);
+	case GRPQUOTA:
+		return from_kgid(targ, kqid.gid);
+	case PRJQUOTA:
+		return from_kprojid(targ, kqid.projid);
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(from_kqid);
+
+/**
+ *	from_kqid_munged - Create a qid from a kqid user-namespace pair.
+ *	@targ: The user namespace we want a qid in.
+ *	@kqid: The kernel internal quota identifier to start with.
+ *
+ *	Map @kqid into the user-namespace specified by @targ and
+ *	return the resulting qid.
+ *
+ *	There is always a mapping into the initial user_namespace.
+ *
+ *	Unlike from_kqid from_kqid_munged never fails and always
+ *	returns a valid projid.  This makes from_kqid_munged
+ *	appropriate for use in places where failing to provide
+ *	a qid_t is not a good option.
+ *
+ *	If @kqid has no mapping in @targ the kqid.type specific
+ *	overflow identifier is returned.
+ */
+qid_t from_kqid_munged(struct user_namespace *targ, struct kqid kqid)
+{
+	switch (kqid.type) {
+	case USRQUOTA:
+		return from_kuid_munged(targ, kqid.uid);
+	case GRPQUOTA:
+		return from_kgid_munged(targ, kqid.gid);
+	case PRJQUOTA:
+		return from_kprojid_munged(targ, kqid.projid);
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(from_kqid_munged);
+
+/**
+ *	qid_valid - Report if a valid value is stored in a kqid.
+ *	@qid: The kernel internal quota identifier to test.
+ */
+bool qid_valid(struct kqid qid)
+{
+	switch (qid.type) {
+	case USRQUOTA:
+		return uid_valid(qid.uid);
+	case GRPQUOTA:
+		return gid_valid(qid.gid);
+	case PRJQUOTA:
+		return projid_valid(qid.projid);
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL(qid_valid);
diff --git a/fs/quota/netlink.c b/fs/quota/netlink.c
index d67908b407d9..16e8abb7709b 100644
--- a/fs/quota/netlink.c
+++ b/fs/quota/netlink.c
@@ -30,7 +30,7 @@ static struct genl_family quota_genl_family = {
  *
  */
 
-void quota_send_warning(short type, unsigned int id, dev_t dev,
+void quota_send_warning(struct kqid qid, dev_t dev,
 			const char warntype)
 {
 	static atomic_t seq;
@@ -56,10 +56,11 @@ void quota_send_warning(short type, unsigned int id, dev_t dev,
 		  "VFS: Cannot store netlink header in quota warning.\n");
 		goto err_out;
 	}
-	ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, type);
+	ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, qid.type);
 	if (ret)
 		goto attr_err_out;
-	ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, id);
+	ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID,
+			  from_kqid_munged(&init_user_ns, qid));
 	if (ret)
 		goto attr_err_out;
 	ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
@@ -71,7 +72,8 @@ void quota_send_warning(short type, unsigned int id, dev_t dev,
 	ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
 	if (ret)
 		goto attr_err_out;
-	ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current_uid());
+	ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID,
+			  from_kuid_munged(&init_user_ns, current_uid()));
 	if (ret)
 		goto attr_err_out;
 	genlmsg_end(skb, msg_head);
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 6f155788cbc6..ff0135d6bc51 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -32,8 +32,8 @@ static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
 	/* allow to query information for dquots we "own" */
 	case Q_GETQUOTA:
 	case Q_XGETQUOTA:
-		if ((type == USRQUOTA && current_euid() == id) ||
-		    (type == GRPQUOTA && in_egroup_p(id)))
+		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
+		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))
 			break;
 		/*FALLTHROUGH*/
 	default:
@@ -130,13 +130,17 @@ static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
 static int quota_getquota(struct super_block *sb, int type, qid_t id,
 			  void __user *addr)
 {
+	struct kqid qid;
 	struct fs_disk_quota fdq;
 	struct if_dqblk idq;
 	int ret;
 
 	if (!sb->s_qcop->get_dqblk)
 		return -ENOSYS;
-	ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
+	qid = make_kqid(current_user_ns(), type, id);
+	if (!qid_valid(qid))
+		return -EINVAL;
+	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 	if (ret)
 		return ret;
 	copy_to_if_dqblk(&idq, &fdq);
@@ -176,13 +180,17 @@ static int quota_setquota(struct super_block *sb, int type, qid_t id,
 {
 	struct fs_disk_quota fdq;
 	struct if_dqblk idq;
+	struct kqid qid;
 
 	if (copy_from_user(&idq, addr, sizeof(idq)))
 		return -EFAULT;
 	if (!sb->s_qcop->set_dqblk)
 		return -ENOSYS;
+	qid = make_kqid(current_user_ns(), type, id);
+	if (!qid_valid(qid))
+		return -EINVAL;
 	copy_from_if_dqblk(&fdq, &idq);
-	return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
+	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 }
 
 static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
@@ -213,23 +221,31 @@ static int quota_setxquota(struct super_block *sb, int type, qid_t id,
 			   void __user *addr)
 {
 	struct fs_disk_quota fdq;
+	struct kqid qid;
 
 	if (copy_from_user(&fdq, addr, sizeof(fdq)))
 		return -EFAULT;
 	if (!sb->s_qcop->set_dqblk)
 		return -ENOSYS;
-	return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
+	qid = make_kqid(current_user_ns(), type, id);
+	if (!qid_valid(qid))
+		return -EINVAL;
+	return sb->s_qcop->set_dqblk(sb, qid, &fdq);
 }
 
 static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 			   void __user *addr)
 {
 	struct fs_disk_quota fdq;
+	struct kqid qid;
 	int ret;
 
 	if (!sb->s_qcop->get_dqblk)
 		return -ENOSYS;
-	ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
+	qid = make_kqid(current_user_ns(), type, id);
+	if (!qid_valid(qid))
+		return -EINVAL;
+	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);
 	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
 		return -EFAULT;
 	return ret;
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index e41c1becf096..d65877fbe8f4 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -22,9 +22,10 @@ MODULE_LICENSE("GPL");
 
 #define __QUOTA_QT_PARANOIA
 
-static int get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
+static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
 {
 	unsigned int epb = info->dqi_usable_bs >> 2;
+	qid_t id = from_kqid(&init_user_ns, qid);
 
 	depth = info->dqi_qtree_depth - depth - 1;
 	while (depth--)
@@ -244,7 +245,7 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
 		/* This is enough as the block is already zeroed and the entry
 		 * list is empty... */
 		info->dqi_free_entry = blk;
-		mark_info_dirty(dquot->dq_sb, dquot->dq_type);
+		mark_info_dirty(dquot->dq_sb, dquot->dq_id.type);
 	}
 	/* Block will be full? */
 	if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
@@ -357,7 +358,7 @@ static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
  */
 int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
 {
-	int type = dquot->dq_type;
+	int type = dquot->dq_id.type;
 	struct super_block *sb = dquot->dq_sb;
 	ssize_t ret;
 	char *ddquot = getdqbuf(info->dqi_entry_size);
@@ -538,8 +539,9 @@ static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
 		ddquot += info->dqi_entry_size;
 	}
 	if (i == qtree_dqstr_in_blk(info)) {
-		quota_error(dquot->dq_sb, "Quota for id %u referenced "
-			    "but not present", dquot->dq_id);
+		quota_error(dquot->dq_sb,
+			    "Quota for id %u referenced but not present",
+			    from_kqid(&init_user_ns, dquot->dq_id));
 		ret = -EIO;
 		goto out_buf;
 	} else {
@@ -589,7 +591,7 @@ static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
 
 int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
 {
-	int type = dquot->dq_type;
+	int type = dquot->dq_id.type;
 	struct super_block *sb = dquot->dq_sb;
 	loff_t offset;
 	char *ddquot;
@@ -607,8 +609,10 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
 		offset = find_dqentry(info, dquot);
 		if (offset <= 0) {	/* Entry not present? */
 			if (offset < 0)
-				quota_error(sb, "Can't read quota structure "
-					    "for id %u", dquot->dq_id);
+				quota_error(sb,"Can't read quota structure "
+					    "for id %u",
+					    from_kqid(&init_user_ns,
+						      dquot->dq_id));
 			dquot->dq_off = 0;
 			set_bit(DQ_FAKE_B, &dquot->dq_flags);
 			memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
@@ -626,7 +630,7 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
 		if (ret >= 0)
 			ret = -EIO;
 		quota_error(sb, "Error while reading quota structure for id %u",
-			    dquot->dq_id);
+			    from_kqid(&init_user_ns, dquot->dq_id));
 		set_bit(DQ_FAKE_B, &dquot->dq_flags);
 		memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
 		kfree(ddquot);
diff --git a/fs/quota/quota_v1.c b/fs/quota/quota_v1.c
index 34b37a67bb16..469c6848b322 100644
--- a/fs/quota/quota_v1.c
+++ b/fs/quota/quota_v1.c
@@ -54,7 +54,7 @@ static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
 
 static int v1_read_dqblk(struct dquot *dquot)
 {
-	int type = dquot->dq_type;
+	int type = dquot->dq_id.type;
 	struct v1_disk_dqblk dqblk;
 
 	if (!sb_dqopt(dquot->dq_sb)->files[type])
@@ -63,7 +63,8 @@ static int v1_read_dqblk(struct dquot *dquot)
 	/* Set structure to 0s in case read fails/is after end of file */
 	memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
 	dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
-			sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
+			sizeof(struct v1_disk_dqblk),
+			v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
 
 	v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
 	if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
@@ -78,12 +79,13 @@ static int v1_read_dqblk(struct dquot *dquot)
 
 static int v1_commit_dqblk(struct dquot *dquot)
 {
-	short type = dquot->dq_type;
+	short type = dquot->dq_id.type;
 	ssize_t ret;
 	struct v1_disk_dqblk dqblk;
 
 	v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
-	if (dquot->dq_id == 0) {
+	if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) ||
+	    ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) {
 		dqblk.dqb_btime =
 			sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
 		dqblk.dqb_itime =
@@ -93,7 +95,7 @@ static int v1_commit_dqblk(struct dquot *dquot)
 	if (sb_dqopt(dquot->dq_sb)->files[type])
 		ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
 			(char *)&dqblk, sizeof(struct v1_disk_dqblk),
-			v1_dqoff(dquot->dq_id));
+			v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
 	if (ret != sizeof(struct v1_disk_dqblk)) {
 		quota_error(dquot->dq_sb, "dquota write failed");
 		if (ret >= 0)
diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
index f1ab3604db5a..02751ec695c5 100644
--- a/fs/quota/quota_v2.c
+++ b/fs/quota/quota_v2.c
@@ -196,7 +196,7 @@ static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 	struct v2r0_disk_dqblk *d = dp;
 	struct mem_dqblk *m = &dquot->dq_dqb;
 	struct qtree_mem_dqinfo *info =
-			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 
 	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
@@ -206,7 +206,7 @@ static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
-	d->dqb_id = cpu_to_le32(dquot->dq_id);
+	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 	if (qtree_entry_unused(info, dp))
 		d->dqb_itime = cpu_to_le64(1);
 }
@@ -215,11 +215,13 @@ static int v2r0_is_id(void *dp, struct dquot *dquot)
 {
 	struct v2r0_disk_dqblk *d = dp;
 	struct qtree_mem_dqinfo *info =
-			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 
 	if (qtree_entry_unused(info, dp))
 		return 0;
-	return le32_to_cpu(d->dqb_id) == dquot->dq_id;
+	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
+				le32_to_cpu(d->dqb_id)),
+		      dquot->dq_id);
 }
 
 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
@@ -247,7 +249,7 @@ static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 	struct v2r1_disk_dqblk *d = dp;
 	struct mem_dqblk *m = &dquot->dq_dqb;
 	struct qtree_mem_dqinfo *info =
-			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 
 	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
@@ -257,7 +259,7 @@ static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
-	d->dqb_id = cpu_to_le32(dquot->dq_id);
+	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 	if (qtree_entry_unused(info, dp))
 		d->dqb_itime = cpu_to_le64(1);
 }
@@ -266,26 +268,28 @@ static int v2r1_is_id(void *dp, struct dquot *dquot)
 {
 	struct v2r1_disk_dqblk *d = dp;
 	struct qtree_mem_dqinfo *info =
-			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 
 	if (qtree_entry_unused(info, dp))
 		return 0;
-	return le32_to_cpu(d->dqb_id) == dquot->dq_id;
+	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
+				le32_to_cpu(d->dqb_id)),
+		      dquot->dq_id);
 }
 
 static int v2_read_dquot(struct dquot *dquot)
 {
-	return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
+	return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 }
 
 static int v2_write_dquot(struct dquot *dquot)
 {
-	return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
+	return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 }
 
 static int v2_release_dquot(struct dquot *dquot)
 {
-	return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
+	return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 }
 
 static int v2_free_file_info(struct super_block *sb, int type)