upload tizen1.0 sourceHEADmaster2.0alpha

1 files changed, 2660 insertions, 0 deletions

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
new file mode 100644
index 00000000..aad1316a
--- /dev/null
+++ b/fs/quota/dquot.c
@@ -0,0 +1,2660 @@
+/*
+ * Implementation of the diskquota system for the LINUX operating system. QUOTA
+ * is implemented using the BSD system call interface as the means of
+ * communication with the user level. This file contains the generic routines
+ * called by the different filesystems on allocation of an inode or block.
+ * These routines take care of the administration needed to have a consistent
+ * diskquota tracking system. The ideas of both user and group quotas are based
+ * on the Melbourne quota system as used on BSD derived systems. The internal
+ * implementation is based on one of the several variants of the LINUX
+ * inode-subsystem with added complexity of the diskquota system.
+ * 
+ * Author:	Marco van Wieringen <mvw@planets.elm.net>
+ *
+ * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
+ *
+ *		Revised list management to avoid races
+ *		-- Bill Hawes, <whawes@star.net>, 9/98
+ *
+ *		Fixed races in dquot_transfer(), dqget() and dquot_alloc_...().
+ *		As the consequence the locking was moved from dquot_decr_...(),
+ *		dquot_incr_...() to calling functions.
+ *		invalidate_dquots() now writes modified dquots.
+ *		Serialized quota_off() and quota_on() for mount point.
+ *		Fixed a few bugs in grow_dquots().
+ *		Fixed deadlock in write_dquot() - we no longer account quotas on
+ *		quota files
+ *		remove_dquot_ref() moved to inode.c - it now traverses through inodes
+ *		add_dquot_ref() restarts after blocking
+ *		Added check for bogus uid and fixed check for group in quotactl.
+ *		Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99
+ *
+ *		Used struct list_head instead of own list struct
+ *		Invalidation of referenced dquots is no longer possible
+ *		Improved free_dquots list management
+ *		Quota and i_blocks are now updated in one place to avoid races
+ *		Warnings are now delayed so we won't block in critical section
+ *		Write updated not to require dquot lock
+ *		Jan Kara, <jack@suse.cz>, 9/2000
+ *
+ *		Added dynamic quota structure allocation
+ *		Jan Kara <jack@suse.cz> 12/2000
+ *
+ *		Rewritten quota interface. Implemented new quota format and
+ *		formats registering.
+ *		Jan Kara, <jack@suse.cz>, 2001,2002
+ *
+ *		New SMP locking.
+ *		Jan Kara, <jack@suse.cz>, 10/2002
+ *
+ *		Added journalled quota support, fix lock inversion problems
+ *		Jan Kara, <jack@suse.cz>, 2003,2004
+ *
+ * (C) Copyright 1994 - 1997 Marco van Wieringen 
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/mm.h>
+#include <linux/time.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/tty.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/sysctl.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/security.h>
+#include <linux/kmod.h>
+#include <linux/namei.h>
+#include <linux/buffer_head.h>
+#include <linux/capability.h>
+#include <linux/quotaops.h>
+#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
+
+#include <asm/uaccess.h>
+
+/*
+ * There are three quota SMP locks. dq_list_lock protects all lists with quotas
+ * and quota formats.
+ * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
+ * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
+ * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
+ * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
+ * modifications of quota state (on quotaon and quotaoff) and readers who care
+ * about latest values take it as well.
+ *
+ * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
+ *   dq_list_lock > dq_state_lock
+ *
+ * Note that some things (eg. sb pointer, type, id) doesn't change during
+ * the life of the dquot structure and so needn't to be protected by a lock
+ *
+ * Any operation working on dquots via inode pointers must hold dqptr_sem.  If
+ * operation is just reading pointers from inode (or not using them at all) the
+ * read lock is enough. If pointers are altered function must hold write lock.
+ * Special care needs to be taken about S_NOQUOTA inode flag (marking that
+ * inode is a quota file). Functions adding pointers from inode to dquots have
+ * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they
+ * have to do all pointer modifications before dropping dqptr_sem. This makes
+ * sure they cannot race with quotaon which first sets S_NOQUOTA flag and
+ * then drops all pointers to dquots from an inode.
+ *
+ * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
+ * from inodes (dquot_alloc_space() and such don't check the dq_lock).
+ * Currently dquot is locked only when it is being read to memory (or space for
+ * it is being allocated) on the first dqget() and when it is being released on
+ * the last dqput(). The allocation and release oparations are serialized by
+ * the dq_lock and by checking the use count in dquot_release().  Write
+ * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
+ * spinlock to internal buffers before writing.
+ *
+ * Lock ordering (including related VFS locks) is the following:
+ *   i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
+ *   dqio_mutex
+ * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
+ * dqptr_sem. But filesystem has to count with the fact that functions such as
+ * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
+ * from inside a transaction to keep filesystem consistency after a crash. Also
+ * filesystems usually want to do some IO on dquot from ->mark_dirty which is
+ * called with dqptr_sem held.
+ * i_mutex on quota files is special (it's below dqio_mutex)
+ */
+
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
+EXPORT_SYMBOL(dq_data_lock);
+
+void __quota_error(struct super_block *sb, const char *func,
+		  const char *fmt, ...)
+{
+	va_list args;
+
+	if (printk_ratelimit()) {
+		va_start(args, fmt);
+		printk(KERN_ERR "Quota error (device %s): %s: ",
+		       sb->s_id, func);
+		vprintk(fmt, args);
+		printk("\n");
+		va_end(args);
+	}
+}
+EXPORT_SYMBOL(__quota_error);
+
+#if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
+static char *quotatypes[] = INITQFNAMES;
+#endif
+static struct quota_format_type *quota_formats;	/* List of registered formats */
+static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES;
+
+/* SLAB cache for dquot structures */
+static struct kmem_cache *dquot_cachep;
+
+int register_quota_format(struct quota_format_type *fmt)
+{
+	spin_lock(&dq_list_lock);
+	fmt->qf_next = quota_formats;
+	quota_formats = fmt;
+	spin_unlock(&dq_list_lock);
+	return 0;
+}
+EXPORT_SYMBOL(register_quota_format);
+
+void unregister_quota_format(struct quota_format_type *fmt)
+{
+	struct quota_format_type **actqf;
+
+	spin_lock(&dq_list_lock);
+	for (actqf = &quota_formats; *actqf && *actqf != fmt;
+	     actqf = &(*actqf)->qf_next)
+		;
+	if (*actqf)
+		*actqf = (*actqf)->qf_next;
+	spin_unlock(&dq_list_lock);
+}
+EXPORT_SYMBOL(unregister_quota_format);
+
+static struct quota_format_type *find_quota_format(int id)
+{
+	struct quota_format_type *actqf;
+
+	spin_lock(&dq_list_lock);
+	for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
+	     actqf = actqf->qf_next)
+		;
+	if (!actqf || !try_module_get(actqf->qf_owner)) {
+		int qm;
+
+		spin_unlock(&dq_list_lock);
+		
+		for (qm = 0; module_names[qm].qm_fmt_id &&
+			     module_names[qm].qm_fmt_id != id; qm++)
+			;
+		if (!module_names[qm].qm_fmt_id ||
+		    request_module(module_names[qm].qm_mod_name))
+			return NULL;
+
+		spin_lock(&dq_list_lock);
+		for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id;
+		     actqf = actqf->qf_next)
+			;
+		if (actqf && !try_module_get(actqf->qf_owner))
+			actqf = NULL;
+	}
+	spin_unlock(&dq_list_lock);
+	return actqf;
+}
+
+static void put_quota_format(struct quota_format_type *fmt)
+{
+	module_put(fmt->qf_owner);
+}
+
+/*
+ * Dquot List Management:
+ * The quota code uses three lists for dquot management: the inuse_list,
+ * free_dquots, and dquot_hash[] array. A single dquot structure may be
+ * on all three lists, depending on its current state.
+ *
+ * All dquots are placed to the end of inuse_list when first created, and this
+ * list is used for invalidate operation, which must look at every dquot.
+ *
+ * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
+ * and this list is searched whenever we need an available dquot.  Dquots are
+ * removed from the list as soon as they are used again, and
+ * dqstats.free_dquots gives the number of dquots on the list. When
+ * dquot is invalidated it's completely released from memory.
+ *
+ * Dquots with a specific identity (device, type and id) are placed on
+ * one of the dquot_hash[] hash chains. The provides an efficient search
+ * mechanism to locate a specific dquot.
+ */
+
+static LIST_HEAD(inuse_list);
+static LIST_HEAD(free_dquots);
+static unsigned int dq_hash_bits, dq_hash_mask;
+static struct hlist_head *dquot_hash;
+
+struct dqstats dqstats;
+EXPORT_SYMBOL(dqstats);
+
+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)
+{
+	unsigned long tmp;
+
+	tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type);
+	return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask;
+}
+
+/*
+ * Following list functions expect dq_list_lock to be held
+ */
+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);
+	hlist_add_head(&dquot->dq_hash, head);
+}
+
+static inline void remove_dquot_hash(struct dquot *dquot)
+{
+	hlist_del_init(&dquot->dq_hash);
+}
+
+static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb,
+				unsigned int id, int type)
+{
+	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)
+			return dquot;
+	}
+	return NULL;
+}
+
+/* Add a dquot to the tail of the free list */
+static inline void put_dquot_last(struct dquot *dquot)
+{
+	list_add_tail(&dquot->dq_free, &free_dquots);
+	dqstats_inc(DQST_FREE_DQUOTS);
+}
+
+static inline void remove_free_dquot(struct dquot *dquot)
+{
+	if (list_empty(&dquot->dq_free))
+		return;
+	list_del_init(&dquot->dq_free);
+	dqstats_dec(DQST_FREE_DQUOTS);
+}
+
+static inline void put_inuse(struct dquot *dquot)
+{
+	/* We add to the back of inuse list so we don't have to restart
+	 * when traversing this list and we block */
+	list_add_tail(&dquot->dq_inuse, &inuse_list);
+	dqstats_inc(DQST_ALLOC_DQUOTS);
+}
+
+static inline void remove_inuse(struct dquot *dquot)
+{
+	dqstats_dec(DQST_ALLOC_DQUOTS);
+	list_del(&dquot->dq_inuse);
+}
+/*
+ * End of list functions needing dq_list_lock
+ */
+
+static void wait_on_dquot(struct dquot *dquot)
+{
+	mutex_lock(&dquot->dq_lock);
+	mutex_unlock(&dquot->dq_lock);
+}
+
+static inline int dquot_dirty(struct dquot *dquot)
+{
+	return test_bit(DQ_MOD_B, &dquot->dq_flags);
+}
+
+static inline int mark_dquot_dirty(struct dquot *dquot)
+{
+	return dquot->dq_sb->dq_op->mark_dirty(dquot);
+}
+
+/* Mark dquot dirty in atomic manner, and return it's old dirty flag state */
+int dquot_mark_dquot_dirty(struct dquot *dquot)
+{
+	int ret = 1;
+
+	/* If quota is dirty already, we don't have to acquire dq_list_lock */
+	if (test_bit(DQ_MOD_B, &dquot->dq_flags))
+		return 1;
+
+	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);
+		ret = 0;
+	}
+	spin_unlock(&dq_list_lock);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_mark_dquot_dirty);
+
+/* Dirtify all the dquots - this can block when journalling */
+static inline int mark_all_dquot_dirty(struct dquot * const *dquot)
+{
+	int ret, err, cnt;
+
+	ret = err = 0;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (dquot[cnt])
+			/* Even in case of error we have to continue */
+			ret = mark_dquot_dirty(dquot[cnt]);
+		if (!err)
+			err = ret;
+	}
+	return err;
+}
+
+static inline void dqput_all(struct dquot **dquot)
+{
+	unsigned int cnt;
+
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		dqput(dquot[cnt]);
+}
+
+/* This function needs dq_list_lock */
+static inline int clear_dquot_dirty(struct dquot *dquot)
+{
+	if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
+		return 0;
+	list_del_init(&dquot->dq_dirty);
+	return 1;
+}
+
+void mark_info_dirty(struct super_block *sb, int type)
+{
+	set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
+}
+EXPORT_SYMBOL(mark_info_dirty);
+
+/*
+ *	Read dquot from disk and alloc space for it
+ */
+
+int dquot_acquire(struct dquot *dquot)
+{
+	int ret = 0, ret2 = 0;
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+	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);
+	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);
+		/* 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 (ret < 0)
+			goto out_iolock;
+		if (ret2 < 0) {
+			ret = ret2;
+			goto out_iolock;
+		}
+	}
+	set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+out_iolock:
+	mutex_unlock(&dqopt->dqio_mutex);
+	mutex_unlock(&dquot->dq_lock);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_acquire);
+
+/*
+ *	Write dquot to disk
+ */
+int dquot_commit(struct dquot *dquot)
+{
+	int ret = 0, ret2 = 0;
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+	mutex_lock(&dqopt->dqio_mutex);
+	spin_lock(&dq_list_lock);
+	if (!clear_dquot_dirty(dquot)) {
+		spin_unlock(&dq_list_lock);
+		goto out_sem;
+	}
+	spin_unlock(&dq_list_lock);
+	/* 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);
+		if (info_dirty(&dqopt->info[dquot->dq_type])) {
+			ret2 = dqopt->ops[dquot->dq_type]->write_file_info(
+						dquot->dq_sb, dquot->dq_type);
+		}
+		if (ret >= 0)
+			ret = ret2;
+	}
+out_sem:
+	mutex_unlock(&dqopt->dqio_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_commit);
+
+/*
+ *	Release dquot
+ */
+int dquot_release(struct dquot *dquot)
+{
+	int ret = 0, ret2 = 0;
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+	mutex_lock(&dquot->dq_lock);
+	/* Check whether we are not racing with some other dqget() */
+	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);
+		/* 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 (ret >= 0)
+			ret = ret2;
+	}
+	clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+	mutex_unlock(&dqopt->dqio_mutex);
+out_dqlock:
+	mutex_unlock(&dquot->dq_lock);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_release);
+
+void dquot_destroy(struct dquot *dquot)
+{
+	kmem_cache_free(dquot_cachep, dquot);
+}
+EXPORT_SYMBOL(dquot_destroy);
+
+static inline void do_destroy_dquot(struct dquot *dquot)
+{
+	dquot->dq_sb->dq_op->destroy_dquot(dquot);
+}
+
+/* Invalidate all dquots on the list. Note that this function is called after
+ * quota is disabled and pointers from inodes removed so there cannot be new
+ * quota users. There can still be some users of quotas due to inodes being
+ * just deleted or pruned by prune_icache() (those are not attached to any
+ * list) or parallel quotactl call. We have to wait for such users.
+ */
+static void invalidate_dquots(struct super_block *sb, int type)
+{
+	struct dquot *dquot, *tmp;
+
+restart:
+	spin_lock(&dq_list_lock);
+	list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
+		if (dquot->dq_sb != sb)
+			continue;
+		if (dquot->dq_type != type)
+			continue;
+		/* Wait for dquot users */
+		if (atomic_read(&dquot->dq_count)) {
+			DEFINE_WAIT(wait);
+
+			atomic_inc(&dquot->dq_count);
+			prepare_to_wait(&dquot->dq_wait_unused, &wait,
+					TASK_UNINTERRUPTIBLE);
+			spin_unlock(&dq_list_lock);
+			/* Once dqput() wakes us up, we know it's time to free
+			 * the dquot.
+			 * IMPORTANT: we rely on the fact that there is always
+			 * at most one process waiting for dquot to free.
+			 * Otherwise dq_count would be > 1 and we would never
+			 * wake up.
+			 */
+			if (atomic_read(&dquot->dq_count) > 1)
+				schedule();
+			finish_wait(&dquot->dq_wait_unused, &wait);
+			dqput(dquot);
+			/* At this moment dquot() need not exist (it could be
+			 * reclaimed by prune_dqcache(). Hence we must
+			 * restart. */
+			goto restart;
+		}
+		/*
+		 * Quota now has no users and it has been written on last
+		 * dqput()
+		 */
+		remove_dquot_hash(dquot);
+		remove_free_dquot(dquot);
+		remove_inuse(dquot);
+		do_destroy_dquot(dquot);
+	}
+	spin_unlock(&dq_list_lock);
+}
+
+/* Call callback for every active dquot on given filesystem */
+int dquot_scan_active(struct super_block *sb,
+		      int (*fn)(struct dquot *dquot, unsigned long priv),
+		      unsigned long priv)
+{
+	struct dquot *dquot, *old_dquot = NULL;
+	int ret = 0;
+
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+	spin_lock(&dq_list_lock);
+	list_for_each_entry(dquot, &inuse_list, dq_inuse) {
+		if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+			continue;
+		if (dquot->dq_sb != sb)
+			continue;
+		/* Now we have active dquot so we can just increase use count */
+		atomic_inc(&dquot->dq_count);
+		spin_unlock(&dq_list_lock);
+		dqstats_inc(DQST_LOOKUPS);
+		dqput(old_dquot);
+		old_dquot = dquot;
+		ret = fn(dquot, priv);
+		if (ret < 0)
+			goto out;
+		spin_lock(&dq_list_lock);
+		/* We are safe to continue now because our dquot could not
+		 * be moved out of the inuse list while we hold the reference */
+	}
+	spin_unlock(&dq_list_lock);
+out:
+	dqput(old_dquot);
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_scan_active);
+
+int dquot_quota_sync(struct super_block *sb, int type, int wait)
+{
+	struct list_head *dirty;
+	struct dquot *dquot;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int cnt;
+
+	mutex_lock(&dqopt->dqonoff_mutex);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		if (!sb_has_quota_active(sb, cnt))
+			continue;
+		spin_lock(&dq_list_lock);
+		dirty = &dqopt->info[cnt].dqi_dirty_list;
+		while (!list_empty(dirty)) {
+			dquot = list_first_entry(dirty, struct dquot,
+						 dq_dirty);
+			/* Dirty and inactive can be only bad dquot... */
+			if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+				clear_dquot_dirty(dquot);
+				continue;
+			}
+			/* Now we have active dquot from which someone is
+ 			 * holding reference so we can safely just increase
+			 * use count */
+			atomic_inc(&dquot->dq_count);
+			spin_unlock(&dq_list_lock);
+			dqstats_inc(DQST_LOOKUPS);
+			sb->dq_op->write_dquot(dquot);
+			dqput(dquot);
+			spin_lock(&dq_list_lock);
+		}
+		spin_unlock(&dq_list_lock);
+	}
+
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
+		    && info_dirty(&dqopt->info[cnt]))
+			sb->dq_op->write_info(sb, cnt);
+	dqstats_inc(DQST_SYNCS);
+	mutex_unlock(&dqopt->dqonoff_mutex);
+
+	if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE))
+		return 0;
+
+	/* This is not very clever (and fast) but currently I don't know about
+	 * any other simple way of getting quota data to disk and we must get
+	 * them there for userspace to be visible... */
+	if (sb->s_op->sync_fs)
+		sb->s_op->sync_fs(sb, 1);
+	sync_blockdev(sb->s_bdev);
+
+	/*
+	 * Now when everything is written we can discard the pagecache so
+	 * that userspace sees the changes.
+	 */
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		if (!sb_has_quota_active(sb, cnt))
+			continue;
+		mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex,
+				  I_MUTEX_QUOTA);
+		truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0);
+		mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex);
+	}
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(dquot_quota_sync);
+
+/* Free unused dquots from cache */
+static void prune_dqcache(int count)
+{
+	struct list_head *head;
+	struct dquot *dquot;
+
+	head = free_dquots.prev;
+	while (head != &free_dquots && count) {
+		dquot = list_entry(head, struct dquot, dq_free);
+		remove_dquot_hash(dquot);
+		remove_free_dquot(dquot);
+		remove_inuse(dquot);
+		do_destroy_dquot(dquot);
+		count--;
+		head = free_dquots.prev;
+	}
+}
+
+/*
+ * This is called from kswapd when we think we need some
+ * more memory
+ */
+static int shrink_dqcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
+{
+	if (nr) {
+		spin_lock(&dq_list_lock);
+		prune_dqcache(nr);
+		spin_unlock(&dq_list_lock);
+	}
+	return ((unsigned)
+		percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
+		/100) * sysctl_vfs_cache_pressure;
+}
+
+static struct shrinker dqcache_shrinker = {
+	.shrink = shrink_dqcache_memory,
+	.seeks = DEFAULT_SEEKS,
+};
+
+/*
+ * Put reference to dquot
+ * NOTE: If you change this function please check whether dqput_blocks() works right...
+ */
+void dqput(struct dquot *dquot)
+{
+	int ret;
+
+	if (!dquot)
+		return;
+#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);
+		BUG();
+	}
+#endif
+	dqstats_inc(DQST_DROPS);
+we_slept:
+	spin_lock(&dq_list_lock);
+	if (atomic_read(&dquot->dq_count) > 1) {
+		/* 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) &&
+		    atomic_read(&dquot->dq_count) == 1)
+			wake_up(&dquot->dq_wait_unused);
+		spin_unlock(&dq_list_lock);
+		return;
+	}
+	/* Need to release dquot? */
+	if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
+		spin_unlock(&dq_list_lock);
+		/* Commit dquot before releasing */
+		ret = dquot->dq_sb->dq_op->write_dquot(dquot);
+		if (ret < 0) {
+			quota_error(dquot->dq_sb, "Can't write quota structure"
+				    " (error %d). Quota may get out of sync!",
+				    ret);
+			/*
+			 * We clear dirty bit anyway, so that we avoid
+			 * infinite loop here
+			 */
+			spin_lock(&dq_list_lock);
+			clear_dquot_dirty(dquot);
+			spin_unlock(&dq_list_lock);
+		}
+		goto we_slept;
+	}
+	/* Clear flag in case dquot was inactive (something bad happened) */
+	clear_dquot_dirty(dquot);
+	if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
+		spin_unlock(&dq_list_lock);
+		dquot->dq_sb->dq_op->release_dquot(dquot);
+		goto we_slept;
+	}
+	atomic_dec(&dquot->dq_count);
+#ifdef CONFIG_QUOTA_DEBUG
+	/* sanity check */
+	BUG_ON(!list_empty(&dquot->dq_free));
+#endif
+	put_dquot_last(dquot);
+	spin_unlock(&dq_list_lock);
+}
+EXPORT_SYMBOL(dqput);
+
+struct dquot *dquot_alloc(struct super_block *sb, int type)
+{
+	return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
+}
+EXPORT_SYMBOL(dquot_alloc);
+
+static struct dquot *get_empty_dquot(struct super_block *sb, int type)
+{
+	struct dquot *dquot;
+
+	dquot = sb->dq_op->alloc_dquot(sb, type);
+	if(!dquot)
+		return NULL;
+
+	mutex_init(&dquot->dq_lock);
+	INIT_LIST_HEAD(&dquot->dq_free);
+	INIT_LIST_HEAD(&dquot->dq_inuse);
+	INIT_HLIST_NODE(&dquot->dq_hash);
+	INIT_LIST_HEAD(&dquot->dq_dirty);
+	init_waitqueue_head(&dquot->dq_wait_unused);
+	dquot->dq_sb = sb;
+	dquot->dq_type = type;
+	atomic_set(&dquot->dq_count, 1);
+
+	return dquot;
+}
+
+/*
+ * Get reference to dquot
+ *
+ * Locking is slightly tricky here. We are guarded from parallel quotaoff()
+ * destroying our dquot by:
+ *   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)
+{
+	unsigned int hashent = hashfn(sb, id, type);
+	struct dquot *dquot = NULL, *empty = NULL;
+
+        if (!sb_has_quota_active(sb, type))
+		return NULL;
+we_slept:
+	spin_lock(&dq_list_lock);
+	spin_lock(&dq_state_lock);
+	if (!sb_has_quota_active(sb, 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);
+	if (!dquot) {
+		if (!empty) {
+			spin_unlock(&dq_list_lock);
+			empty = get_empty_dquot(sb, type);
+			if (!empty)
+				schedule();	/* Try to wait for a moment... */
+			goto we_slept;
+		}
+		dquot = empty;
+		empty = NULL;
+		dquot->dq_id = id;
+		/* all dquots go on the inuse_list */
+		put_inuse(dquot);
+		/* hash it first so it can be found */
+		insert_dquot_hash(dquot);
+		spin_unlock(&dq_list_lock);
+		dqstats_inc(DQST_LOOKUPS);
+	} else {
+		if (!atomic_read(&dquot->dq_count))
+			remove_free_dquot(dquot);
+		atomic_inc(&dquot->dq_count);
+		spin_unlock(&dq_list_lock);
+		dqstats_inc(DQST_CACHE_HITS);
+		dqstats_inc(DQST_LOOKUPS);
+	}
+	/* Wait for dq_lock - after this we know that either dquot_release() is
+	 * already finished or it will be canceled due to dq_count > 1 test */
+	wait_on_dquot(dquot);
+	/* Read the dquot / allocate space in quota file */
+	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) &&
+	    sb->dq_op->acquire_dquot(dquot) < 0) {
+		dqput(dquot);
+		dquot = NULL;
+		goto out;
+	}
+#ifdef CONFIG_QUOTA_DEBUG
+	BUG_ON(!dquot->dq_sb);	/* Has somebody invalidated entry under us? */
+#endif
+out:
+	if (empty)
+		do_destroy_dquot(empty);
+
+	return dquot;
+}
+EXPORT_SYMBOL(dqget);
+
+static int dqinit_needed(struct inode *inode, int type)
+{
+	int cnt;
+
+	if (IS_NOQUOTA(inode))
+		return 0;
+	if (type != -1)
+		return !inode->i_dquot[type];
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if (!inode->i_dquot[cnt])
+			return 1;
+	return 0;
+}
+
+/* This routine is guarded by dqonoff_mutex mutex */
+static void add_dquot_ref(struct super_block *sb, int type)
+{
+	struct inode *inode, *old_inode = NULL;
+#ifdef CONFIG_QUOTA_DEBUG
+	int reserved = 0;
+#endif
+
+	spin_lock(&inode_lock);
+	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+		if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+			continue;
+#ifdef CONFIG_QUOTA_DEBUG
+		if (unlikely(inode_get_rsv_space(inode) > 0))
+			reserved = 1;
+#endif
+		if (!atomic_read(&inode->i_writecount))
+			continue;
+		if (!dqinit_needed(inode, type))
+			continue;
+
+		__iget(inode);
+		spin_unlock(&inode_lock);
+
+		iput(old_inode);
+		__dquot_initialize(inode, type);
+		/* We hold a reference to 'inode' so it couldn't have been
+		 * removed from s_inodes list while we dropped the inode_lock.
+		 * We cannot iput the inode now as we can be holding the last
+		 * reference and we cannot iput it under inode_lock. So we
+		 * keep the reference and iput it later. */
+		old_inode = inode;
+		spin_lock(&inode_lock);
+	}
+	spin_unlock(&inode_lock);
+	iput(old_inode);
+
+#ifdef CONFIG_QUOTA_DEBUG
+	if (reserved) {
+		quota_error(sb, "Writes happened before quota was turned on "
+			"thus quota information is probably inconsistent. "
+			"Please run quotacheck(8)");
+	}
+#endif
+}
+
+/*
+ * Return 0 if dqput() won't block.
+ * (note that 1 doesn't necessarily mean blocking)
+ */
+static inline int dqput_blocks(struct dquot *dquot)
+{
+	if (atomic_read(&dquot->dq_count) <= 1)
+		return 1;
+	return 0;
+}
+
+/*
+ * Remove references to dquots from inode and add dquot to list for freeing
+ * if we have the last referece to dquot
+ * We can't race with anybody because we hold dqptr_sem for writing...
+ */
+static int remove_inode_dquot_ref(struct inode *inode, int type,
+				  struct list_head *tofree_head)
+{
+	struct dquot *dquot = inode->i_dquot[type];
+
+	inode->i_dquot[type] = NULL;
+	if (dquot) {
+		if (dqput_blocks(dquot)) {
+#ifdef CONFIG_QUOTA_DEBUG
+			if (atomic_read(&dquot->dq_count) != 1)
+				quota_error(inode->i_sb, "Adding dquot with "
+					    "dq_count %d to dispose list",
+					    atomic_read(&dquot->dq_count));
+#endif
+			spin_lock(&dq_list_lock);
+			/* As dquot must have currently users it can't be on
+			 * the free list... */
+			list_add(&dquot->dq_free, tofree_head);
+			spin_unlock(&dq_list_lock);
+			return 1;
+		}
+		else
+			dqput(dquot);   /* We have guaranteed we won't block */
+	}
+	return 0;
+}
+
+/*
+ * Free list of dquots
+ * Dquots are removed from inodes and no new references can be got so we are
+ * the only ones holding reference
+ */
+static void put_dquot_list(struct list_head *tofree_head)
+{
+	struct list_head *act_head;
+	struct dquot *dquot;
+
+	act_head = tofree_head->next;
+	while (act_head != tofree_head) {
+		dquot = list_entry(act_head, struct dquot, dq_free);
+		act_head = act_head->next;
+		/* Remove dquot from the list so we won't have problems... */
+		list_del_init(&dquot->dq_free);
+		dqput(dquot);
+	}
+}
+
+static void remove_dquot_ref(struct super_block *sb, int type,
+		struct list_head *tofree_head)
+{
+	struct inode *inode;
+	int reserved = 0;
+
+	spin_lock(&inode_lock);
+	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+		/*
+		 *  We have to scan also I_NEW inodes because they can already
+		 *  have quota pointer initialized. Luckily, we need to touch
+		 *  only quota pointers and these have separate locking
+		 *  (dqptr_sem).
+		 */
+		if (!IS_NOQUOTA(inode)) {
+			if (unlikely(inode_get_rsv_space(inode) > 0))
+				reserved = 1;
+			remove_inode_dquot_ref(inode, type, tofree_head);
+		}
+	}
+	spin_unlock(&inode_lock);
+#ifdef CONFIG_QUOTA_DEBUG
+	if (reserved) {
+		printk(KERN_WARNING "VFS (%s): Writes happened after quota"
+			" was disabled thus quota information is probably "
+			"inconsistent. Please run quotacheck(8).\n", sb->s_id);
+	}
+#endif
+}
+
+/* Gather all references from inodes and drop them */
+static void drop_dquot_ref(struct super_block *sb, int type)
+{
+	LIST_HEAD(tofree_head);
+
+	if (sb->dq_op) {
+		down_write(&sb_dqopt(sb)->dqptr_sem);
+		remove_dquot_ref(sb, type, &tofree_head);
+		up_write(&sb_dqopt(sb)->dqptr_sem);
+		put_dquot_list(&tofree_head);
+	}
+}
+
+static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
+{
+	dquot->dq_dqb.dqb_curinodes += number;
+}
+
+static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
+{
+	dquot->dq_dqb.dqb_curspace += number;
+}
+
+static inline void dquot_resv_space(struct dquot *dquot, qsize_t number)
+{
+	dquot->dq_dqb.dqb_rsvspace += number;
+}
+
+/*
+ * Claim reserved quota space
+ */
+static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
+{
+	if (dquot->dq_dqb.dqb_rsvspace < number) {
+		WARN_ON_ONCE(1);
+		number = dquot->dq_dqb.dqb_rsvspace;
+	}
+	dquot->dq_dqb.dqb_curspace += number;
+	dquot->dq_dqb.dqb_rsvspace -= number;
+}
+
+static inline
+void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
+{
+	if (dquot->dq_dqb.dqb_rsvspace >= number)
+		dquot->dq_dqb.dqb_rsvspace -= number;
+	else {
+		WARN_ON_ONCE(1);
+		dquot->dq_dqb.dqb_rsvspace = 0;
+	}
+}
+
+static void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
+{
+	if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
+	    dquot->dq_dqb.dqb_curinodes >= number)
+		dquot->dq_dqb.dqb_curinodes -= number;
+	else
+		dquot->dq_dqb.dqb_curinodes = 0;
+	if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
+		dquot->dq_dqb.dqb_itime = (time_t) 0;
+	clear_bit(DQ_INODES_B, &dquot->dq_flags);
+}
+
+static void dquot_decr_space(struct dquot *dquot, qsize_t number)
+{
+	if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
+	    dquot->dq_dqb.dqb_curspace >= number)
+		dquot->dq_dqb.dqb_curspace -= number;
+	else
+		dquot->dq_dqb.dqb_curspace = 0;
+	if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
+		dquot->dq_dqb.dqb_btime = (time_t) 0;
+	clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+}
+
+static int warning_issued(struct dquot *dquot, const int warntype)
+{
+	int flag = (warntype == QUOTA_NL_BHARDWARN ||
+		warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
+		((warntype == QUOTA_NL_IHARDWARN ||
+		warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
+
+	if (!flag)
+		return 0;
+	return test_and_set_bit(flag, &dquot->dq_flags);
+}
+
+#ifdef CONFIG_PRINT_QUOTA_WARNING
+static int flag_print_warnings = 1;
+
+static int need_print_warning(struct dquot *dquot)
+{
+	if (!flag_print_warnings)
+		return 0;
+
+	switch (dquot->dq_type) {
+		case USRQUOTA:
+			return current_fsuid() == dquot->dq_id;
+		case GRPQUOTA:
+			return in_group_p(dquot->dq_id);
+	}
+	return 0;
+}
+
+/* Print warning to user which exceeded quota */
+static void print_warning(struct dquot *dquot, const int warntype)
+{
+	char *msg = NULL;
+	struct tty_struct *tty;
+
+	if (warntype == QUOTA_NL_IHARDBELOW ||
+	    warntype == QUOTA_NL_ISOFTBELOW ||
+	    warntype == QUOTA_NL_BHARDBELOW ||
+	    warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
+		return;
+
+	tty = get_current_tty();
+	if (!tty)
+		return;
+	tty_write_message(tty, dquot->dq_sb->s_id);
+	if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN)
+		tty_write_message(tty, ": warning, ");
+	else
+		tty_write_message(tty, ": write failed, ");
+	tty_write_message(tty, quotatypes[dquot->dq_type]);
+	switch (warntype) {
+		case QUOTA_NL_IHARDWARN:
+			msg = " file limit reached.\r\n";
+			break;
+		case QUOTA_NL_ISOFTLONGWARN:
+			msg = " file quota exceeded too long.\r\n";
+			break;
+		case QUOTA_NL_ISOFTWARN:
+			msg = " file quota exceeded.\r\n";
+			break;
+		case QUOTA_NL_BHARDWARN:
+			msg = " block limit reached.\r\n";
+			break;
+		case QUOTA_NL_BSOFTLONGWARN:
+			msg = " block quota exceeded too long.\r\n";
+			break;
+		case QUOTA_NL_BSOFTWARN:
+			msg = " block quota exceeded.\r\n";
+			break;
+	}
+	tty_write_message(tty, msg);
+	tty_kref_put(tty);
+}
+#endif
+
+/*
+ * Write warnings to the console and send warning messages over netlink.
+ *
+ * Note that this function can sleep.
+ */
+static void flush_warnings(struct dquot *const *dquots, char *warntype)
+{
+	struct dquot *dq;
+	int i;
+
+	for (i = 0; i < MAXQUOTAS; i++) {
+		dq = dquots[i];
+		if (dq && warntype[i] != QUOTA_NL_NOWARN &&
+		    !warning_issued(dq, warntype[i])) {
+#ifdef CONFIG_PRINT_QUOTA_WARNING
+			print_warning(dq, warntype[i]);
+#endif
+			quota_send_warning(dq->dq_type, dq->dq_id,
+					   dq->dq_sb->s_dev, warntype[i]);
+		}
+	}
+}
+
+static int ignore_hardlimit(struct dquot *dquot)
+{
+	struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type];
+
+	return capable(CAP_SYS_RESOURCE) &&
+	       (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD ||
+		!(info->dqi_flags & V1_DQF_RSQUASH));
+}
+
+/* needs dq_data_lock */
+static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
+{
+	qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes;
+
+	*warntype = QUOTA_NL_NOWARN;
+	if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
+	    test_bit(DQ_FAKE_B, &dquot->dq_flags))
+		return 0;
+
+	if (dquot->dq_dqb.dqb_ihardlimit &&
+	    newinodes > dquot->dq_dqb.dqb_ihardlimit &&
+            !ignore_hardlimit(dquot)) {
+		*warntype = QUOTA_NL_IHARDWARN;
+		return -EDQUOT;
+	}
+
+	if (dquot->dq_dqb.dqb_isoftlimit &&
+	    newinodes > dquot->dq_dqb.dqb_isoftlimit &&
+	    dquot->dq_dqb.dqb_itime &&
+	    get_seconds() >= dquot->dq_dqb.dqb_itime &&
+            !ignore_hardlimit(dquot)) {
+		*warntype = QUOTA_NL_ISOFTLONGWARN;
+		return -EDQUOT;
+	}
+
+	if (dquot->dq_dqb.dqb_isoftlimit &&
+	    newinodes > dquot->dq_dqb.dqb_isoftlimit &&
+	    dquot->dq_dqb.dqb_itime == 0) {
+		*warntype = QUOTA_NL_ISOFTWARN;
+		dquot->dq_dqb.dqb_itime = get_seconds() +
+		    sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
+	}
+
+	return 0;
+}
+
+/* needs dq_data_lock */
+static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
+{
+	qsize_t tspace;
+	struct super_block *sb = dquot->dq_sb;
+
+	*warntype = QUOTA_NL_NOWARN;
+	if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) ||
+	    test_bit(DQ_FAKE_B, &dquot->dq_flags))
+		return 0;
+
+	tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
+		+ space;
+
+	if (dquot->dq_dqb.dqb_bhardlimit &&
+	    tspace > dquot->dq_dqb.dqb_bhardlimit &&
+            !ignore_hardlimit(dquot)) {
+		if (!prealloc)
+			*warntype = QUOTA_NL_BHARDWARN;
+		return -EDQUOT;
+	}
+
+	if (dquot->dq_dqb.dqb_bsoftlimit &&
+	    tspace > dquot->dq_dqb.dqb_bsoftlimit &&
+	    dquot->dq_dqb.dqb_btime &&
+	    get_seconds() >= dquot->dq_dqb.dqb_btime &&
+            !ignore_hardlimit(dquot)) {
+		if (!prealloc)
+			*warntype = QUOTA_NL_BSOFTLONGWARN;
+		return -EDQUOT;
+	}
+
+	if (dquot->dq_dqb.dqb_bsoftlimit &&
+	    tspace > dquot->dq_dqb.dqb_bsoftlimit &&
+	    dquot->dq_dqb.dqb_btime == 0) {
+		if (!prealloc) {
+			*warntype = QUOTA_NL_BSOFTWARN;
+			dquot->dq_dqb.dqb_btime = get_seconds() +
+			    sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace;
+		}
+		else
+			/*
+			 * We don't allow preallocation to exceed softlimit so exceeding will
+			 * be always printed
+			 */
+			return -EDQUOT;
+	}
+
+	return 0;
+}
+
+static int info_idq_free(struct dquot *dquot, qsize_t inodes)
+{
+	qsize_t newinodes;
+
+	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))
+		return QUOTA_NL_NOWARN;
+
+	newinodes = dquot->dq_dqb.dqb_curinodes - inodes;
+	if (newinodes <= dquot->dq_dqb.dqb_isoftlimit)
+		return QUOTA_NL_ISOFTBELOW;
+	if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit &&
+	    newinodes < dquot->dq_dqb.dqb_ihardlimit)
+		return QUOTA_NL_IHARDBELOW;
+	return QUOTA_NL_NOWARN;
+}
+
+static int info_bdq_free(struct dquot *dquot, qsize_t space)
+{
+	if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
+	    dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
+		return QUOTA_NL_NOWARN;
+
+	if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
+		return QUOTA_NL_BSOFTBELOW;
+	if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
+	    dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
+		return QUOTA_NL_BHARDBELOW;
+	return QUOTA_NL_NOWARN;
+}
+
+static int dquot_active(const struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+
+	if (IS_NOQUOTA(inode))
+		return 0;
+	return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
+}
+
+/*
+ * Initialize quota pointers in inode
+ *
+ * We do things in a bit complicated way but by that we avoid calling
+ * dqget() and thus filesystem callbacks under dqptr_sem.
+ *
+ * It is better to call this function outside of any transaction as it
+ * might need a lot of space in journal for dquot structure allocation.
+ */
+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;
+	qsize_t rsv;
+
+	/* First test before acquiring mutex - solves deadlocks when we
+         * re-enter the quota code and are already holding the mutex */
+	if (!dquot_active(inode))
+		return;
+
+	/* First get references to structures we might need. */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		got[cnt] = NULL;
+		if (type != -1 && cnt != type)
+			continue;
+		switch (cnt) {
+		case USRQUOTA:
+			id = inode->i_uid;
+			break;
+		case GRPQUOTA:
+			id = inode->i_gid;
+			break;
+		}
+		got[cnt] = dqget(sb, id, cnt);
+	}
+
+	down_write(&sb_dqopt(sb)->dqptr_sem);
+	if (IS_NOQUOTA(inode))
+		goto out_err;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		/* Avoid races with quotaoff() */
+		if (!sb_has_quota_active(sb, cnt))
+			continue;
+		if (!inode->i_dquot[cnt]) {
+			inode->i_dquot[cnt] = got[cnt];
+			got[cnt] = NULL;
+			/*
+			 * Make quota reservation system happy if someone
+			 * did a write before quota was turned on
+			 */
+			rsv = inode_get_rsv_space(inode);
+			if (unlikely(rsv))
+				dquot_resv_space(inode->i_dquot[cnt], rsv);
+		}
+	}
+out_err:
+	up_write(&sb_dqopt(sb)->dqptr_sem);
+	/* Drop unused references */
+	dqput_all(got);
+}
+
+void dquot_initialize(struct inode *inode)
+{
+	__dquot_initialize(inode, -1);
+}
+EXPORT_SYMBOL(dquot_initialize);
+
+/*
+ * 	Release all quotas referenced by inode
+ */
+static void __dquot_drop(struct inode *inode)
+{
+	int cnt;
+	struct dquot *put[MAXQUOTAS];
+
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		put[cnt] = inode->i_dquot[cnt];
+		inode->i_dquot[cnt] = NULL;
+	}
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	dqput_all(put);
+}
+
+void dquot_drop(struct inode *inode)
+{
+	int cnt;
+
+	if (IS_NOQUOTA(inode))
+		return;
+
+	/*
+	 * Test before calling to rule out calls from proc and such
+	 * where we are not allowed to block. Note that this is
+	 * actually reliable test even without the lock - the caller
+	 * must assure that nobody can come after the DQUOT_DROP and
+	 * add quota pointers back anyway.
+	 */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt])
+			break;
+	}
+
+	if (cnt < MAXQUOTAS)
+		__dquot_drop(inode);
+}
+EXPORT_SYMBOL(dquot_drop);
+
+/*
+ * inode_reserved_space is managed internally by quota, and protected by
+ * i_lock similar to i_blocks+i_bytes.
+ */
+static qsize_t *inode_reserved_space(struct inode * inode)
+{
+	/* Filesystem must explicitly define it's own method in order to use
+	 * quota reservation interface */
+	BUG_ON(!inode->i_sb->dq_op->get_reserved_space);
+	return inode->i_sb->dq_op->get_reserved_space(inode);
+}
+
+void inode_add_rsv_space(struct inode *inode, qsize_t number)
+{
+	spin_lock(&inode->i_lock);
+	*inode_reserved_space(inode) += number;
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL(inode_add_rsv_space);
+
+void inode_claim_rsv_space(struct inode *inode, qsize_t number)
+{
+	spin_lock(&inode->i_lock);
+	*inode_reserved_space(inode) -= number;
+	__inode_add_bytes(inode, number);
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL(inode_claim_rsv_space);
+
+void inode_sub_rsv_space(struct inode *inode, qsize_t number)
+{
+	spin_lock(&inode->i_lock);
+	*inode_reserved_space(inode) -= number;
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL(inode_sub_rsv_space);
+
+static qsize_t inode_get_rsv_space(struct inode *inode)
+{
+	qsize_t ret;
+
+	if (!inode->i_sb->dq_op->get_reserved_space)
+		return 0;
+	spin_lock(&inode->i_lock);
+	ret = *inode_reserved_space(inode);
+	spin_unlock(&inode->i_lock);
+	return ret;
+}
+
+static void inode_incr_space(struct inode *inode, qsize_t number,
+				int reserve)
+{
+	if (reserve)
+		inode_add_rsv_space(inode, number);
+	else
+		inode_add_bytes(inode, number);
+}
+
+static void inode_decr_space(struct inode *inode, qsize_t number, int reserve)
+{
+	if (reserve)
+		inode_sub_rsv_space(inode, number);
+	else
+		inode_sub_bytes(inode, number);
+}
+
+/*
+ * This functions updates i_blocks+i_bytes fields and quota information
+ * (together with appropriate checks).
+ *
+ * NOTE: We absolutely rely on the fact that caller dirties the inode
+ * (usually helpers in quotaops.h care about this) and holds a handle for
+ * the current transaction so that dquot write and inode write go into the
+ * same transaction.
+ */
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
+{
+	int cnt, ret = 0;
+	char warntype[MAXQUOTAS];
+	int warn = flags & DQUOT_SPACE_WARN;
+	int reserve = flags & DQUOT_SPACE_RESERVE;
+	int nofail = flags & DQUOT_SPACE_NOFAIL;
+
+	/*
+	 * First test before acquiring mutex - solves deadlocks when we
+	 * re-enter the quota code and are already holding the mutex
+	 */
+	if (!dquot_active(inode)) {
+		inode_incr_space(inode, number, reserve);
+		goto out;
+	}
+
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		warntype[cnt] = QUOTA_NL_NOWARN;
+
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!inode->i_dquot[cnt])
+			continue;
+		ret = check_bdq(inode->i_dquot[cnt], number, !warn,
+				warntype+cnt);
+		if (ret && !nofail) {
+			spin_unlock(&dq_data_lock);
+			goto out_flush_warn;
+		}
+	}
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!inode->i_dquot[cnt])
+			continue;
+		if (reserve)
+			dquot_resv_space(inode->i_dquot[cnt], number);
+		else
+			dquot_incr_space(inode->i_dquot[cnt], number);
+	}
+	inode_incr_space(inode, number, reserve);
+	spin_unlock(&dq_data_lock);
+
+	if (reserve)
+		goto out_flush_warn;
+	mark_all_dquot_dirty(inode->i_dquot);
+out_flush_warn:
+	flush_warnings(inode->i_dquot, warntype);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+out:
+	return ret;
+}
+EXPORT_SYMBOL(__dquot_alloc_space);
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_alloc_inode(const struct inode *inode)
+{
+	int cnt, ret = 0;
+	char warntype[MAXQUOTAS];
+
+	/* First test before acquiring mutex - solves deadlocks when we
+         * re-enter the quota code and are already holding the mutex */
+	if (!dquot_active(inode))
+		return 0;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		warntype[cnt] = QUOTA_NL_NOWARN;
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!inode->i_dquot[cnt])
+			continue;
+		ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt);
+		if (ret)
+			goto warn_put_all;
+	}
+
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!inode->i_dquot[cnt])
+			continue;
+		dquot_incr_inodes(inode->i_dquot[cnt], 1);
+	}
+
+warn_put_all:
+	spin_unlock(&dq_data_lock);
+	if (ret == 0)
+		mark_all_dquot_dirty(inode->i_dquot);
+	flush_warnings(inode->i_dquot, warntype);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_alloc_inode);
+
+/*
+ * Convert in-memory reserved quotas to real consumed quotas
+ */
+int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
+{
+	int cnt;
+
+	if (!dquot_active(inode)) {
+		inode_claim_rsv_space(inode, number);
+		return 0;
+	}
+
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	spin_lock(&dq_data_lock);
+	/* Claim reserved quotas to allocated quotas */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt])
+			dquot_claim_reserved_space(inode->i_dquot[cnt],
+							number);
+	}
+	/* Update inode bytes */
+	inode_claim_rsv_space(inode, number);
+	spin_unlock(&dq_data_lock);
+	mark_all_dquot_dirty(inode->i_dquot);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return 0;
+}
+EXPORT_SYMBOL(dquot_claim_space_nodirty);
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
+{
+	unsigned int cnt;
+	char warntype[MAXQUOTAS];
+	int reserve = flags & DQUOT_SPACE_RESERVE;
+
+	/* First test before acquiring mutex - solves deadlocks when we
+         * re-enter the quota code and are already holding the mutex */
+	if (!dquot_active(inode)) {
+		inode_decr_space(inode, number, reserve);
+		return;
+	}
+
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!inode->i_dquot[cnt])
+			continue;
+		warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number);
+		if (reserve)
+			dquot_free_reserved_space(inode->i_dquot[cnt], number);
+		else
+			dquot_decr_space(inode->i_dquot[cnt], number);
+	}
+	inode_decr_space(inode, number, reserve);
+	spin_unlock(&dq_data_lock);
+
+	if (reserve)
+		goto out_unlock;
+	mark_all_dquot_dirty(inode->i_dquot);
+out_unlock:
+	flush_warnings(inode->i_dquot, warntype);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+}
+EXPORT_SYMBOL(__dquot_free_space);
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+void dquot_free_inode(const struct inode *inode)
+{
+	unsigned int cnt;
+	char warntype[MAXQUOTAS];
+
+	/* First test before acquiring mutex - solves deadlocks when we
+         * re-enter the quota code and are already holding the mutex */
+	if (!dquot_active(inode))
+		return;
+
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!inode->i_dquot[cnt])
+			continue;
+		warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1);
+		dquot_decr_inodes(inode->i_dquot[cnt], 1);
+	}
+	spin_unlock(&dq_data_lock);
+	mark_all_dquot_dirty(inode->i_dquot);
+	flush_warnings(inode->i_dquot, warntype);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+}
+EXPORT_SYMBOL(dquot_free_inode);
+
+/*
+ * Transfer the number of inode and blocks from one diskquota to an other.
+ * On success, dquot references in transfer_to are consumed and references
+ * to original dquots that need to be released are placed there. On failure,
+ * references are kept untouched.
+ *
+ * This operation can block, but only after everything is updated
+ * A transaction must be started when entering this function.
+ *
+ */
+int __dquot_transfer(struct inode *inode, struct dquot **transfer_to)
+{
+	qsize_t space, cur_space;
+	qsize_t rsv_space = 0;
+	struct dquot *transfer_from[MAXQUOTAS] = {};
+	int cnt, ret = 0;
+	char warntype_to[MAXQUOTAS];
+	char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
+
+	/* First test before acquiring mutex - solves deadlocks when we
+         * re-enter the quota code and are already holding the mutex */
+	if (IS_NOQUOTA(inode))
+		return 0;
+	/* Initialize the arrays */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		warntype_to[cnt] = QUOTA_NL_NOWARN;
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	if (IS_NOQUOTA(inode)) {	/* File without quota accounting? */
+		up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		return 0;
+	}
+	spin_lock(&dq_data_lock);
+	cur_space = inode_get_bytes(inode);
+	rsv_space = inode_get_rsv_space(inode);
+	space = cur_space + rsv_space;
+	/* Build the transfer_from list and check the limits */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (!transfer_to[cnt])
+			continue;
+		transfer_from[cnt] = inode->i_dquot[cnt];
+		ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt);
+		if (ret)
+			goto over_quota;
+		ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt);
+		if (ret)
+			goto over_quota;
+	}
+
+	/*
+	 * Finally perform the needed transfer from transfer_from to transfer_to
+	 */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		/*
+		 * Skip changes for same uid or gid or for turned off quota-type.
+		 */
+		if (!transfer_to[cnt])
+			continue;
+
+		/* Due to IO error we might not have transfer_from[] structure */
+		if (transfer_from[cnt]) {
+			warntype_from_inodes[cnt] =
+				info_idq_free(transfer_from[cnt], 1);
+			warntype_from_space[cnt] =
+				info_bdq_free(transfer_from[cnt], space);
+			dquot_decr_inodes(transfer_from[cnt], 1);
+			dquot_decr_space(transfer_from[cnt], cur_space);
+			dquot_free_reserved_space(transfer_from[cnt],
+						  rsv_space);
+		}
+
+		dquot_incr_inodes(transfer_to[cnt], 1);
+		dquot_incr_space(transfer_to[cnt], cur_space);
+		dquot_resv_space(transfer_to[cnt], rsv_space);
+
+		inode->i_dquot[cnt] = transfer_to[cnt];
+	}
+	spin_unlock(&dq_data_lock);
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+
+	mark_all_dquot_dirty(transfer_from);
+	mark_all_dquot_dirty(transfer_to);
+	/* Pass back references to put */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		transfer_to[cnt] = transfer_from[cnt];
+warn:
+	flush_warnings(transfer_to, warntype_to);
+	flush_warnings(transfer_from, warntype_from_inodes);
+	flush_warnings(transfer_from, warntype_from_space);
+	return ret;
+over_quota:
+	spin_unlock(&dq_data_lock);
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	goto warn;
+}
+EXPORT_SYMBOL(__dquot_transfer);
+
+/* Wrapper for transferring ownership of an inode for uid/gid only
+ * Called from FSXXX_setattr()
+ */
+int dquot_transfer(struct inode *inode, struct iattr *iattr)
+{
+	struct dquot *transfer_to[MAXQUOTAS] = {};
+	struct super_block *sb = inode->i_sb;
+	int ret;
+
+	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);
+
+	ret = __dquot_transfer(inode, transfer_to);
+	dqput_all(transfer_to);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_transfer);
+
+/*
+ * Write info of quota file to disk
+ */
+int dquot_commit_info(struct super_block *sb, int type)
+{
+	int ret;
+	struct quota_info *dqopt = sb_dqopt(sb);
+
+	mutex_lock(&dqopt->dqio_mutex);
+	ret = dqopt->ops[type]->write_file_info(sb, type);
+	mutex_unlock(&dqopt->dqio_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(dquot_commit_info);
+
+/*
+ * Definitions of diskquota operations.
+ */
+const struct dquot_operations dquot_operations = {
+	.write_dquot	= dquot_commit,
+	.acquire_dquot	= dquot_acquire,
+	.release_dquot	= dquot_release,
+	.mark_dirty	= dquot_mark_dquot_dirty,
+	.write_info	= dquot_commit_info,
+	.alloc_dquot	= dquot_alloc,
+	.destroy_dquot	= dquot_destroy,
+};
+EXPORT_SYMBOL(dquot_operations);
+
+/*
+ * Generic helper for ->open on filesystems supporting disk quotas.
+ */
+int dquot_file_open(struct inode *inode, struct file *file)
+{
+	int error;
+
+	error = generic_file_open(inode, file);
+	if (!error && (file->f_mode & FMODE_WRITE))
+		dquot_initialize(inode);
+	return error;
+}
+EXPORT_SYMBOL(dquot_file_open);
+
+/*
+ * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
+ */
+int dquot_disable(struct super_block *sb, int type, unsigned int flags)
+{
+	int cnt, ret = 0;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	struct inode *toputinode[MAXQUOTAS];
+
+	/* Cannot turn off usage accounting without turning off limits, or
+	 * suspend quotas and simultaneously turn quotas off. */
+	if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
+	    || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
+	    DQUOT_USAGE_ENABLED)))
+		return -EINVAL;
+
+	/* We need to serialize quota_off() for device */
+	mutex_lock(&dqopt->dqonoff_mutex);
+
+	/*
+	 * Skip everything if there's nothing to do. We have to do this because
+	 * sometimes we are called when fill_super() failed and calling
+	 * sync_fs() in such cases does no good.
+	 */
+	if (!sb_any_quota_loaded(sb)) {
+		mutex_unlock(&dqopt->dqonoff_mutex);
+		return 0;
+	}
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		toputinode[cnt] = NULL;
+		if (type != -1 && cnt != type)
+			continue;
+		if (!sb_has_quota_loaded(sb, cnt))
+			continue;
+
+		if (flags & DQUOT_SUSPENDED) {
+			spin_lock(&dq_state_lock);
+			dqopt->flags |=
+				dquot_state_flag(DQUOT_SUSPENDED, cnt);
+			spin_unlock(&dq_state_lock);
+		} else {
+			spin_lock(&dq_state_lock);
+			dqopt->flags &= ~dquot_state_flag(flags, cnt);
+			/* Turning off suspended quotas? */
+			if (!sb_has_quota_loaded(sb, cnt) &&
+			    sb_has_quota_suspended(sb, cnt)) {
+				dqopt->flags &=	~dquot_state_flag(
+							DQUOT_SUSPENDED, cnt);
+				spin_unlock(&dq_state_lock);
+				iput(dqopt->files[cnt]);
+				dqopt->files[cnt] = NULL;
+				continue;
+			}
+			spin_unlock(&dq_state_lock);
+		}
+
+		/* We still have to keep quota loaded? */
+		if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
+			continue;
+
+		/* Note: these are blocking operations */
+		drop_dquot_ref(sb, cnt);
+		invalidate_dquots(sb, cnt);
+		/*
+		 * Now all dquots should be invalidated, all writes done so we
+		 * should be only users of the info. No locks needed.
+		 */
+		if (info_dirty(&dqopt->info[cnt]))
+			sb->dq_op->write_info(sb, cnt);
+		if (dqopt->ops[cnt]->free_file_info)
+			dqopt->ops[cnt]->free_file_info(sb, cnt);
+		put_quota_format(dqopt->info[cnt].dqi_format);
+
+		toputinode[cnt] = dqopt->files[cnt];
+		if (!sb_has_quota_loaded(sb, cnt))
+			dqopt->files[cnt] = NULL;
+		dqopt->info[cnt].dqi_flags = 0;
+		dqopt->info[cnt].dqi_igrace = 0;
+		dqopt->info[cnt].dqi_bgrace = 0;
+		dqopt->ops[cnt] = NULL;
+	}
+	mutex_unlock(&dqopt->dqonoff_mutex);
+
+	/* Skip syncing and setting flags if quota files are hidden */
+	if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
+		goto put_inodes;
+
+	/* Sync the superblock so that buffers with quota data are written to
+	 * disk (and so userspace sees correct data afterwards). */
+	if (sb->s_op->sync_fs)
+		sb->s_op->sync_fs(sb, 1);
+	sync_blockdev(sb->s_bdev);
+	/* Now the quota files are just ordinary files and we can set the
+	 * inode flags back. Moreover we discard the pagecache so that
+	 * userspace sees the writes we did bypassing the pagecache. We
+	 * must also discard the blockdev buffers so that we see the
+	 * changes done by userspace on the next quotaon() */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if (toputinode[cnt]) {
+			mutex_lock(&dqopt->dqonoff_mutex);
+			/* If quota was reenabled in the meantime, we have
+			 * nothing to do */
+			if (!sb_has_quota_loaded(sb, cnt)) {
+				mutex_lock_nested(&toputinode[cnt]->i_mutex,
+						  I_MUTEX_QUOTA);
+				toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
+				  S_NOATIME | S_NOQUOTA);
+				truncate_inode_pages(&toputinode[cnt]->i_data,
+						     0);
+				mutex_unlock(&toputinode[cnt]->i_mutex);
+				mark_inode_dirty_sync(toputinode[cnt]);
+			}
+			mutex_unlock(&dqopt->dqonoff_mutex);
+		}
+	if (sb->s_bdev)
+		invalidate_bdev(sb->s_bdev);
+put_inodes:
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if (toputinode[cnt]) {
+			/* On remount RO, we keep the inode pointer so that we
+			 * can reenable quota on the subsequent remount RW. We
+			 * have to check 'flags' variable and not use sb_has_
+			 * function because another quotaon / quotaoff could
+			 * change global state before we got here. We refuse
+			 * to suspend quotas when there is pending delete on
+			 * the quota file... */
+			if (!(flags & DQUOT_SUSPENDED))
+				iput(toputinode[cnt]);
+			else if (!toputinode[cnt]->i_nlink)
+				ret = -EBUSY;
+		}
+	return ret;
+}
+EXPORT_SYMBOL(dquot_disable);
+
+int dquot_quota_off(struct super_block *sb, int type)
+{
+	return dquot_disable(sb, type,
+			     DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
+}
+EXPORT_SYMBOL(dquot_quota_off);
+
+/*
+ *	Turn quotas on on a device
+ */
+
+/*
+ * Helper function to turn quotas on when we already have the inode of
+ * quota file and no quota information is loaded.
+ */
+static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
+	unsigned int flags)
+{
+	struct quota_format_type *fmt = find_quota_format(format_id);
+	struct super_block *sb = inode->i_sb;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int error;
+	int oldflags = -1;
+
+	if (!fmt)
+		return -ESRCH;
+	if (!S_ISREG(inode->i_mode)) {
+		error = -EACCES;
+		goto out_fmt;
+	}
+	if (IS_RDONLY(inode)) {
+		error = -EROFS;
+		goto out_fmt;
+	}
+	if (!sb->s_op->quota_write || !sb->s_op->quota_read) {
+		error = -EINVAL;
+		goto out_fmt;
+	}
+	/* Usage always has to be set... */
+	if (!(flags & DQUOT_USAGE_ENABLED)) {
+		error = -EINVAL;
+		goto out_fmt;
+	}
+
+	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+		/* As we bypass the pagecache we must now flush all the
+		 * dirty data and invalidate caches so that kernel sees
+		 * changes from userspace. It is not enough to just flush
+		 * the quota file since if blocksize < pagesize, invalidation
+		 * of the cache could fail because of other unrelated dirty
+		 * data */
+		sync_filesystem(sb);
+		invalidate_bdev(sb->s_bdev);
+	}
+	mutex_lock(&dqopt->dqonoff_mutex);
+	if (sb_has_quota_loaded(sb, type)) {
+		error = -EBUSY;
+		goto out_lock;
+	}
+
+	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+		/* We don't want quota and atime on quota files (deadlocks
+		 * possible) Also nobody should write to the file - we use
+		 * special IO operations which ignore the immutable bit. */
+		mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
+		oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
+					     S_NOQUOTA);
+		inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
+		mutex_unlock(&inode->i_mutex);
+		/*
+		 * When S_NOQUOTA is set, remove dquot references as no more
+		 * references can be added
+		 */
+		__dquot_drop(inode);
+	}
+
+	error = -EIO;
+	dqopt->files[type] = igrab(inode);
+	if (!dqopt->files[type])
+		goto out_lock;
+	error = -EINVAL;
+	if (!fmt->qf_ops->check_quota_file(sb, type))
+		goto out_file_init;
+
+	dqopt->ops[type] = fmt->qf_ops;
+	dqopt->info[type].dqi_format = fmt;
+	dqopt->info[type].dqi_fmt_id = format_id;
+	INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
+	mutex_lock(&dqopt->dqio_mutex);
+	error = dqopt->ops[type]->read_file_info(sb, type);
+	if (error < 0) {
+		mutex_unlock(&dqopt->dqio_mutex);
+		goto out_file_init;
+	}
+	mutex_unlock(&dqopt->dqio_mutex);
+	spin_lock(&dq_state_lock);
+	dqopt->flags |= dquot_state_flag(flags, type);
+	spin_unlock(&dq_state_lock);
+
+	add_dquot_ref(sb, type);
+	mutex_unlock(&dqopt->dqonoff_mutex);
+
+	return 0;
+
+out_file_init:
+	dqopt->files[type] = NULL;
+	iput(inode);
+out_lock:
+	if (oldflags != -1) {
+		mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
+		/* Set the flags back (in the case of accidental quotaon()
+		 * on a wrong file we don't want to mess up the flags) */
+		inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
+		inode->i_flags |= oldflags;
+		mutex_unlock(&inode->i_mutex);
+	}
+	mutex_unlock(&dqopt->dqonoff_mutex);
+out_fmt:
+	put_quota_format(fmt);
+
+	return error; 
+}
+
+/* Reenable quotas on remount RW */
+int dquot_resume(struct super_block *sb, int type)
+{
+	struct quota_info *dqopt = sb_dqopt(sb);
+	struct inode *inode;
+	int ret = 0, cnt;
+	unsigned int flags;
+
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+
+		mutex_lock(&dqopt->dqonoff_mutex);
+		if (!sb_has_quota_suspended(sb, cnt)) {
+			mutex_unlock(&dqopt->dqonoff_mutex);
+			continue;
+		}
+		inode = dqopt->files[cnt];
+		dqopt->files[cnt] = NULL;
+		spin_lock(&dq_state_lock);
+		flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
+							DQUOT_LIMITS_ENABLED,
+							cnt);
+		dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
+		spin_unlock(&dq_state_lock);
+		mutex_unlock(&dqopt->dqonoff_mutex);
+
+		flags = dquot_generic_flag(flags, cnt);
+		ret = vfs_load_quota_inode(inode, cnt,
+				dqopt->info[cnt].dqi_fmt_id, flags);
+		iput(inode);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(dquot_resume);
+
+int dquot_quota_on_path(struct super_block *sb, int type, int format_id,
+		      struct path *path)
+{
+	int error = security_quota_on(path->dentry);
+	if (error)
+		return error;
+	/* Quota file not on the same filesystem? */
+	if (path->mnt->mnt_sb != sb)
+		error = -EXDEV;
+	else
+		error = vfs_load_quota_inode(path->dentry->d_inode, type,
+					     format_id, DQUOT_USAGE_ENABLED |
+					     DQUOT_LIMITS_ENABLED);
+	return error;
+}
+EXPORT_SYMBOL(dquot_quota_on_path);
+
+int dquot_quota_on(struct super_block *sb, int type, int format_id, char *name)
+{
+	struct path path;
+	int error;
+
+	error = kern_path(name, LOOKUP_FOLLOW, &path);
+	if (!error) {
+		error = dquot_quota_on_path(sb, type, format_id, &path);
+		path_put(&path);
+	}
+	return error;
+}
+EXPORT_SYMBOL(dquot_quota_on);
+
+/*
+ * More powerful function for turning on quotas allowing setting
+ * of individual quota flags
+ */
+int dquot_enable(struct inode *inode, int type, int format_id,
+		 unsigned int flags)
+{
+	int ret = 0;
+	struct super_block *sb = inode->i_sb;
+	struct quota_info *dqopt = sb_dqopt(sb);
+
+	/* Just unsuspend quotas? */
+	BUG_ON(flags & DQUOT_SUSPENDED);
+
+	if (!flags)
+		return 0;
+	/* Just updating flags needed? */
+	if (sb_has_quota_loaded(sb, type)) {
+		mutex_lock(&dqopt->dqonoff_mutex);
+		/* Now do a reliable test... */
+		if (!sb_has_quota_loaded(sb, type)) {
+			mutex_unlock(&dqopt->dqonoff_mutex);
+			goto load_quota;
+		}
+		if (flags & DQUOT_USAGE_ENABLED &&
+		    sb_has_quota_usage_enabled(sb, type)) {
+			ret = -EBUSY;
+			goto out_lock;
+		}
+		if (flags & DQUOT_LIMITS_ENABLED &&
+		    sb_has_quota_limits_enabled(sb, type)) {
+			ret = -EBUSY;
+			goto out_lock;
+		}
+		spin_lock(&dq_state_lock);
+		sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
+		spin_unlock(&dq_state_lock);
+out_lock:
+		mutex_unlock(&dqopt->dqonoff_mutex);
+		return ret;
+	}
+
+load_quota:
+	return vfs_load_quota_inode(inode, type, format_id, flags);
+}
+EXPORT_SYMBOL(dquot_enable);
+
+/*
+ * This function is used when filesystem needs to initialize quotas
+ * during mount time.
+ */
+int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
+		int format_id, int type)
+{
+	struct dentry *dentry;
+	int error;
+
+	mutex_lock(&sb->s_root->d_inode->i_mutex);
+	dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
+	mutex_unlock(&sb->s_root->d_inode->i_mutex);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	if (!dentry->d_inode) {
+		error = -ENOENT;
+		goto out;
+	}
+
+	error = security_quota_on(dentry);
+	if (!error)
+		error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
+				DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
+
+out:
+	dput(dentry);
+	return error;
+}
+EXPORT_SYMBOL(dquot_quota_on_mount);
+
+static inline qsize_t qbtos(qsize_t blocks)
+{
+	return blocks << QIF_DQBLKSIZE_BITS;
+}
+
+static inline qsize_t stoqb(qsize_t space)
+{
+	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
+}
+
+/* Generic routine for getting common part of quota structure */
+static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
+{
+	struct mem_dqblk *dm = &dquot->dq_dqb;
+
+	memset(di, 0, sizeof(*di));
+	di->d_version = FS_DQUOT_VERSION;
+	di->d_flags = dquot->dq_type == USRQUOTA ?
+			FS_USER_QUOTA : FS_GROUP_QUOTA;
+	di->d_id = dquot->dq_id;
+
+	spin_lock(&dq_data_lock);
+	di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit);
+	di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit);
+	di->d_ino_hardlimit = dm->dqb_ihardlimit;
+	di->d_ino_softlimit = dm->dqb_isoftlimit;
+	di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace;
+	di->d_icount = dm->dqb_curinodes;
+	di->d_btimer = dm->dqb_btime;
+	di->d_itimer = dm->dqb_itime;
+	spin_unlock(&dq_data_lock);
+}
+
+int dquot_get_dqblk(struct super_block *sb, int type, qid_t id,
+		    struct fs_disk_quota *di)
+{
+	struct dquot *dquot;
+
+	dquot = dqget(sb, id, type);
+	if (!dquot)
+		return -ESRCH;
+	do_get_dqblk(dquot, di);
+	dqput(dquot);
+
+	return 0;
+}
+EXPORT_SYMBOL(dquot_get_dqblk);
+
+#define VFS_FS_DQ_MASK \
+	(FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \
+	 FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \
+	 FS_DQ_BTIMER | FS_DQ_ITIMER)
+
+/* Generic routine for setting common part of quota structure */
+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];
+
+	if (di->d_fieldmask & ~VFS_FS_DQ_MASK)
+		return -EINVAL;
+
+	if (((di->d_fieldmask & FS_DQ_BSOFT) &&
+	     (di->d_blk_softlimit > dqi->dqi_maxblimit)) ||
+	    ((di->d_fieldmask & FS_DQ_BHARD) &&
+	     (di->d_blk_hardlimit > dqi->dqi_maxblimit)) ||
+	    ((di->d_fieldmask & FS_DQ_ISOFT) &&
+	     (di->d_ino_softlimit > dqi->dqi_maxilimit)) ||
+	    ((di->d_fieldmask & FS_DQ_IHARD) &&
+	     (di->d_ino_hardlimit > dqi->dqi_maxilimit)))
+		return -ERANGE;
+
+	spin_lock(&dq_data_lock);
+	if (di->d_fieldmask & FS_DQ_BCOUNT) {
+		dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace;
+		check_blim = 1;
+		set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
+	}
+
+	if (di->d_fieldmask & FS_DQ_BSOFT)
+		dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit);
+	if (di->d_fieldmask & FS_DQ_BHARD)
+		dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit);
+	if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) {
+		check_blim = 1;
+		set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
+	}
+
+	if (di->d_fieldmask & FS_DQ_ICOUNT) {
+		dm->dqb_curinodes = di->d_icount;
+		check_ilim = 1;
+		set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
+	}
+
+	if (di->d_fieldmask & FS_DQ_ISOFT)
+		dm->dqb_isoftlimit = di->d_ino_softlimit;
+	if (di->d_fieldmask & FS_DQ_IHARD)
+		dm->dqb_ihardlimit = di->d_ino_hardlimit;
+	if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) {
+		check_ilim = 1;
+		set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
+	}
+
+	if (di->d_fieldmask & FS_DQ_BTIMER) {
+		dm->dqb_btime = di->d_btimer;
+		check_blim = 1;
+		set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
+	}
+
+	if (di->d_fieldmask & FS_DQ_ITIMER) {
+		dm->dqb_itime = di->d_itimer;
+		check_ilim = 1;
+		set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
+	}
+
+	if (check_blim) {
+		if (!dm->dqb_bsoftlimit ||
+		    dm->dqb_curspace < dm->dqb_bsoftlimit) {
+			dm->dqb_btime = 0;
+			clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+		} else if (!(di->d_fieldmask & FS_DQ_BTIMER))
+			/* Set grace only if user hasn't provided his own... */
+			dm->dqb_btime = get_seconds() + dqi->dqi_bgrace;
+	}
+	if (check_ilim) {
+		if (!dm->dqb_isoftlimit ||
+		    dm->dqb_curinodes < dm->dqb_isoftlimit) {
+			dm->dqb_itime = 0;
+			clear_bit(DQ_INODES_B, &dquot->dq_flags);
+		} else if (!(di->d_fieldmask & FS_DQ_ITIMER))
+			/* Set grace only if user hasn't provided his own... */
+			dm->dqb_itime = get_seconds() + dqi->dqi_igrace;
+	}
+	if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit ||
+	    dm->dqb_isoftlimit)
+		clear_bit(DQ_FAKE_B, &dquot->dq_flags);
+	else
+		set_bit(DQ_FAKE_B, &dquot->dq_flags);
+	spin_unlock(&dq_data_lock);
+	mark_dquot_dirty(dquot);
+
+	return 0;
+}
+
+int dquot_set_dqblk(struct super_block *sb, int type, qid_t id,
+		  struct fs_disk_quota *di)
+{
+	struct dquot *dquot;
+	int rc;
+
+	dquot = dqget(sb, id, type);
+	if (!dquot) {
+		rc = -ESRCH;
+		goto out;
+	}
+	rc = do_set_dqblk(dquot, di);
+	dqput(dquot);
+out:
+	return rc;
+}
+EXPORT_SYMBOL(dquot_set_dqblk);
+
+/* Generic routine for getting common part of quota file information */
+int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+{
+	struct mem_dqinfo *mi;
+  
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+	if (!sb_has_quota_active(sb, type)) {
+		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+		return -ESRCH;
+	}
+	mi = sb_dqopt(sb)->info + type;
+	spin_lock(&dq_data_lock);
+	ii->dqi_bgrace = mi->dqi_bgrace;
+	ii->dqi_igrace = mi->dqi_igrace;
+	ii->dqi_flags = mi->dqi_flags & DQF_MASK;
+	ii->dqi_valid = IIF_ALL;
+	spin_unlock(&dq_data_lock);
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(dquot_get_dqinfo);
+
+/* Generic routine for setting common part of quota file information */
+int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+{
+	struct mem_dqinfo *mi;
+	int err = 0;
+
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+	if (!sb_has_quota_active(sb, type)) {
+		err = -ESRCH;
+		goto out;
+	}
+	mi = sb_dqopt(sb)->info + type;
+	spin_lock(&dq_data_lock);
+	if (ii->dqi_valid & IIF_BGRACE)
+		mi->dqi_bgrace = ii->dqi_bgrace;
+	if (ii->dqi_valid & IIF_IGRACE)
+		mi->dqi_igrace = ii->dqi_igrace;
+	if (ii->dqi_valid & IIF_FLAGS)
+		mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) |
+				(ii->dqi_flags & DQF_MASK);
+	spin_unlock(&dq_data_lock);
+	mark_info_dirty(sb, type);
+	/* Force write to disk */
+	sb->dq_op->write_info(sb, type);
+out:
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+	return err;
+}
+EXPORT_SYMBOL(dquot_set_dqinfo);
+
+const struct quotactl_ops dquot_quotactl_ops = {
+	.quota_on	= dquot_quota_on,
+	.quota_off	= dquot_quota_off,
+	.quota_sync	= dquot_quota_sync,
+	.get_info	= dquot_get_dqinfo,
+	.set_info	= dquot_set_dqinfo,
+	.get_dqblk	= dquot_get_dqblk,
+	.set_dqblk	= dquot_set_dqblk
+};
+EXPORT_SYMBOL(dquot_quotactl_ops);
+
+static int do_proc_dqstats(struct ctl_table *table, int write,
+		     void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	unsigned int type = (int *)table->data - dqstats.stat;
+
+	/* Update global table */
+	dqstats.stat[type] =
+			percpu_counter_sum_positive(&dqstats.counter[type]);
+	return proc_dointvec(table, write, buffer, lenp, ppos);
+}
+
+static ctl_table fs_dqstats_table[] = {
+	{
+		.procname	= "lookups",
+		.data		= &dqstats.stat[DQST_LOOKUPS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "drops",
+		.data		= &dqstats.stat[DQST_DROPS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "reads",
+		.data		= &dqstats.stat[DQST_READS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "writes",
+		.data		= &dqstats.stat[DQST_WRITES],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "cache_hits",
+		.data		= &dqstats.stat[DQST_CACHE_HITS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "allocated_dquots",
+		.data		= &dqstats.stat[DQST_ALLOC_DQUOTS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "free_dquots",
+		.data		= &dqstats.stat[DQST_FREE_DQUOTS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+	{
+		.procname	= "syncs",
+		.data		= &dqstats.stat[DQST_SYNCS],
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= do_proc_dqstats,
+	},
+#ifdef CONFIG_PRINT_QUOTA_WARNING
+	{
+		.procname	= "warnings",
+		.data		= &flag_print_warnings,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#endif
+	{ },
+};
+
+static ctl_table fs_table[] = {
+	{
+		.procname	= "quota",
+		.mode		= 0555,
+		.child		= fs_dqstats_table,
+	},
+	{ },
+};
+
+static ctl_table sys_table[] = {
+	{
+		.procname	= "fs",
+		.mode		= 0555,
+		.child		= fs_table,
+	},
+	{ },
+};
+
+static int __init dquot_init(void)
+{
+	int i, ret;
+	unsigned long nr_hash, order;
+
+	printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
+
+	register_sysctl_table(sys_table);
+
+	dquot_cachep = kmem_cache_create("dquot",
+			sizeof(struct dquot), sizeof(unsigned long) * 4,
+			(SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
+				SLAB_MEM_SPREAD|SLAB_PANIC),
+			NULL);
+
+	order = 0;
+	dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
+	if (!dquot_hash)
+		panic("Cannot create dquot hash table");
+
+	for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
+		ret = percpu_counter_init(&dqstats.counter[i], 0);
+		if (ret)
+			panic("Cannot create dquot stat counters");
+	}
+
+	/* Find power-of-two hlist_heads which can fit into allocation */
+	nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
+	dq_hash_bits = 0;
+	do {
+		dq_hash_bits++;
+	} while (nr_hash >> dq_hash_bits);
+	dq_hash_bits--;
+
+	nr_hash = 1UL << dq_hash_bits;
+	dq_hash_mask = nr_hash - 1;
+	for (i = 0; i < nr_hash; i++)
+		INIT_HLIST_HEAD(dquot_hash + i);
+
+	printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
+			nr_hash, order, (PAGE_SIZE << order));
+
+	register_shrinker(&dqcache_shrinker);
+
+	return 0;
+}
+module_init(dquot_init);