Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1850 insertions, 0 deletions

diff --git a/fs/dquot.c b/fs/dquot.c
new file mode 100644
index 0000000..11048e0
--- /dev/null
+++ b/fs/dquot.c
@@ -0,0 +1,1850 @@
+/*
+ * 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.
+ * 
+ * Version: $Id: dquot.c,v 6.3 1996/11/17 18:35:34 mvw Exp mvw $
+ * 
+ * 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/smp_lock.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 <asm/uaccess.h>
+
+#define __DQUOT_PARANOIA
+
+/*
+ * There are two quota SMP locks. dq_list_lock protects all lists with quotas
+ * and quota formats and also dqstats structure containing statistics about the
+ * lists. 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().
+ *
+ * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_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
+ * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
+ * for altering the flag i_sem is also needed).  If operation is holding
+ * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
+ * dqonoff_sem.
+ * This locking assures that:
+ *   a) update/access to dquot pointers in inode is serialized
+ *   b) everyone is guarded against invalidate_dquots()
+ *
+ * Each dquot has its dq_lock semaphore. 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_sem > dqonoff_sem > iprune_sem > journal_lock > dqptr_sem >
+ *   > dquot->dq_lock > dqio_sem
+ * i_sem on quota files is special (it's below dqio_sem)
+ */
+
+static DEFINE_SPINLOCK(dq_list_lock);
+DEFINE_SPINLOCK(dq_data_lock);
+
+static char *quotatypes[] = INITQFNAMES;
+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 kmem_cache_t *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;
+}
+
+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);
+}
+
+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;
+
+static void dqput(struct dquot *dquot);
+
+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 = 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 inline 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 NODQUOT;
+}
+
+/* Add a dquot to the tail of the free list */
+static inline void put_dquot_last(struct dquot *dquot)
+{
+	list_add(&dquot->dq_free, free_dquots.prev);
+	dqstats.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.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(&dquot->dq_inuse, inuse_list.prev);
+	dqstats.allocated_dquots++;
+}
+
+static inline void remove_inuse(struct dquot *dquot)
+{
+	dqstats.allocated_dquots--;
+	list_del(&dquot->dq_inuse);
+}
+/*
+ * End of list functions needing dq_list_lock
+ */
+
+static void wait_on_dquot(struct dquot *dquot)
+{
+	down(&dquot->dq_lock);
+	up(&dquot->dq_lock);
+}
+
+#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
+
+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);
+	spin_unlock(&dq_list_lock);
+	return 0;
+}
+
+/* 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);
+
+	down(&dquot->dq_lock);
+	down(&dqopt->dqio_sem);
+	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:
+	up(&dqopt->dqio_sem);
+	up(&dquot->dq_lock);
+	return ret;
+}
+
+/*
+ *	Write dquot to disk
+ */
+int dquot_commit(struct dquot *dquot)
+{
+	int ret = 0, ret2 = 0;
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+	down(&dqopt->dqio_sem);
+	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:
+	up(&dqopt->dqio_sem);
+	return ret;
+}
+
+/*
+ *	Release dquot
+ */
+int dquot_release(struct dquot *dquot)
+{
+	int ret = 0, ret2 = 0;
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+
+	down(&dquot->dq_lock);
+	/* Check whether we are not racing with some other dqget() */
+	if (atomic_read(&dquot->dq_count) > 1)
+		goto out_dqlock;
+	down(&dqopt->dqio_sem);
+	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);
+	up(&dqopt->dqio_sem);
+out_dqlock:
+	up(&dquot->dq_lock);
+	return ret;
+}
+
+/* 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. Also because we hold dqonoff_sem there can be no quota users
+ * for this sb+type at all. */
+static void invalidate_dquots(struct super_block *sb, int type)
+{
+	struct dquot *dquot;
+	struct list_head *head;
+
+	spin_lock(&dq_list_lock);
+	for (head = inuse_list.next; head != &inuse_list;) {
+		dquot = list_entry(head, struct dquot, dq_inuse);
+		head = head->next;
+		if (dquot->dq_sb != sb)
+			continue;
+		if (dquot->dq_type != type)
+			continue;
+#ifdef __DQUOT_PARANOIA
+		if (atomic_read(&dquot->dq_count))
+			BUG();
+#endif
+		/* Quota now has no users and it has been written on last dqput() */
+		remove_dquot_hash(dquot);
+		remove_free_dquot(dquot);
+		remove_inuse(dquot);
+		kmem_cache_free(dquot_cachep, dquot);
+	}
+	spin_unlock(&dq_list_lock);
+}
+
+int vfs_quota_sync(struct super_block *sb, int type)
+{
+	struct list_head *dirty;
+	struct dquot *dquot;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int cnt;
+
+	down(&dqopt->dqonoff_sem);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		if (!sb_has_quota_enabled(sb, cnt))
+			continue;
+		spin_lock(&dq_list_lock);
+		dirty = &dqopt->info[cnt].dqi_dirty_list;
+		while (!list_empty(dirty)) {
+			dquot = list_entry(dirty->next, 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);
+			dqstats.lookups++;
+			spin_unlock(&dq_list_lock);
+			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_enabled(sb, cnt)
+			&& info_dirty(&dqopt->info[cnt]))
+			sb->dq_op->write_info(sb, cnt);
+	spin_lock(&dq_list_lock);
+	dqstats.syncs++;
+	spin_unlock(&dq_list_lock);
+	up(&dqopt->dqonoff_sem);
+
+	return 0;
+}
+
+/* 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);
+		kmem_cache_free(dquot_cachep, dquot);
+		count--;
+		head = free_dquots.prev;
+	}
+}
+
+/*
+ * This is called from kswapd when we think we need some
+ * more memory
+ */
+
+static int shrink_dqcache_memory(int nr, unsigned int gfp_mask)
+{
+	if (nr) {
+		spin_lock(&dq_list_lock);
+		prune_dqcache(nr);
+		spin_unlock(&dq_list_lock);
+	}
+	return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
+}
+
+/*
+ * Put reference to dquot
+ * NOTE: If you change this function please check whether dqput_blocks() works right...
+ * MUST be called with either dqptr_sem or dqonoff_sem held
+ */
+static void dqput(struct dquot *dquot)
+{
+	if (!dquot)
+		return;
+#ifdef __DQUOT_PARANOIA
+	if (!atomic_read(&dquot->dq_count)) {
+		printk("VFS: dqput: trying to free free dquot\n");
+		printk("VFS: device %s, dquot of %s %d\n",
+			dquot->dq_sb->s_id,
+			quotatypes[dquot->dq_type],
+			dquot->dq_id);
+		BUG();
+	}
+#endif
+	
+	spin_lock(&dq_list_lock);
+	dqstats.drops++;
+	spin_unlock(&dq_list_lock);
+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);
+		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 */
+		dquot->dq_sb->dq_op->write_dquot(dquot);
+		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 __DQUOT_PARANOIA
+	/* sanity check */
+	if (!list_empty(&dquot->dq_free))
+		BUG();
+#endif
+	put_dquot_last(dquot);
+	spin_unlock(&dq_list_lock);
+}
+
+static struct dquot *get_empty_dquot(struct super_block *sb, int type)
+{
+	struct dquot *dquot;
+
+	dquot = kmem_cache_alloc(dquot_cachep, SLAB_NOFS);
+	if(!dquot)
+		return NODQUOT;
+
+	memset((caddr_t)dquot, 0, sizeof(struct dquot));
+	sema_init(&dquot->dq_lock, 1);
+	INIT_LIST_HEAD(&dquot->dq_free);
+	INIT_LIST_HEAD(&dquot->dq_inuse);
+	INIT_HLIST_NODE(&dquot->dq_hash);
+	INIT_LIST_HEAD(&dquot->dq_dirty);
+	dquot->dq_sb = sb;
+	dquot->dq_type = type;
+	atomic_set(&dquot->dq_count, 1);
+
+	return dquot;
+}
+
+/*
+ * Get reference to dquot
+ * MUST be called with either dqptr_sem or dqonoff_sem held
+ */
+static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
+{
+	unsigned int hashent = hashfn(sb, id, type);
+	struct dquot *dquot, *empty = NODQUOT;
+
+        if (!sb_has_quota_enabled(sb, type))
+		return NODQUOT;
+we_slept:
+	spin_lock(&dq_list_lock);
+	if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
+		if (empty == NODQUOT) {
+			spin_unlock(&dq_list_lock);
+			if ((empty = get_empty_dquot(sb, type)) == NODQUOT)
+				schedule();	/* Try to wait for a moment... */
+			goto we_slept;
+		}
+		dquot = empty;
+		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);
+		dqstats.lookups++;
+		spin_unlock(&dq_list_lock);
+	} else {
+		if (!atomic_read(&dquot->dq_count))
+			remove_free_dquot(dquot);
+		atomic_inc(&dquot->dq_count);
+		dqstats.cache_hits++;
+		dqstats.lookups++;
+		spin_unlock(&dq_list_lock);
+		if (empty)
+			kmem_cache_free(dquot_cachep, empty);
+	}
+	/* 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 and instantiate it (everything done only if needed) */
+	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
+		dqput(dquot);
+		return NODQUOT;
+	}
+#ifdef __DQUOT_PARANOIA
+	if (!dquot->dq_sb)	/* Has somebody invalidated entry under us? */
+		BUG();
+#endif
+
+	return dquot;
+}
+
+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] == NODQUOT;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if (inode->i_dquot[cnt] == NODQUOT)
+			return 1;
+	return 0;
+}
+
+/* This routine is guarded by dqonoff_sem semaphore */
+static void add_dquot_ref(struct super_block *sb, int type)
+{
+	struct list_head *p;
+
+restart:
+	file_list_lock();
+	list_for_each(p, &sb->s_files) {
+		struct file *filp = list_entry(p, struct file, f_list);
+		struct inode *inode = filp->f_dentry->d_inode;
+		if (filp->f_mode & FMODE_WRITE && dqinit_needed(inode, type)) {
+			struct dentry *dentry = dget(filp->f_dentry);
+			file_list_unlock();
+			sb->dq_op->initialize(inode, type);
+			dput(dentry);
+			/* As we may have blocked we had better restart... */
+			goto restart;
+		}
+	}
+	file_list_unlock();
+}
+
+/* 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 - add dquot to list for freeing if needed */
+/* We can't race with anybody because we hold dqptr_sem for writing... */
+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] = NODQUOT;
+	if (dquot != NODQUOT) {
+		if (dqput_blocks(dquot)) {
+#ifdef __DQUOT_PARANOIA
+			if (atomic_read(&dquot->dq_count) != 1)
+				printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
+#endif
+			spin_lock(&dq_list_lock);
+			list_add(&dquot->dq_free, tofree_head);	/* As dquot must have currently users it can't be on the free list... */
+			spin_unlock(&dq_list_lock);
+			return 1;
+		}
+		else
+			dqput(dquot);   /* We have guaranteed we won't block */
+	}
+	return 0;
+}
+
+/* Free list of dquots - called from inode.c */
+/* dquots are removed from inodes, 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;
+	/* So now we have dquots on the list... Just free them */
+	while (act_head != tofree_head) {
+		dquot = list_entry(act_head, struct dquot, dq_free);
+		act_head = act_head->next;
+		list_del_init(&dquot->dq_free);	/* Remove dquot from the list so we won't have problems... */
+		dqput(dquot);
+	}
+}
+
+/* Gather all references from inodes and drop them */
+static void drop_dquot_ref(struct super_block *sb, int type)
+{
+	LIST_HEAD(tofree_head);
+
+	/* We need to be guarded against prune_icache to reach all the
+	 * inodes - otherwise some can be on the local list of prune_icache */
+	down(&iprune_sem);
+	down_write(&sb_dqopt(sb)->dqptr_sem);
+	remove_dquot_ref(sb, type, &tofree_head);
+	up_write(&sb_dqopt(sb)->dqptr_sem);
+	up(&iprune_sem);
+	put_dquot_list(&tofree_head);
+}
+
+static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long 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_decr_inodes(struct dquot *dquot, unsigned long number)
+{
+	if (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 inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
+{
+	if (dquot->dq_dqb.dqb_curspace > number)
+		dquot->dq_dqb.dqb_curspace -= number;
+	else
+		dquot->dq_dqb.dqb_curspace = 0;
+	if (toqb(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 flag_print_warnings = 1;
+
+static inline 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;
+}
+
+/* Values of warnings */
+#define NOWARN 0
+#define IHARDWARN 1
+#define ISOFTLONGWARN 2
+#define ISOFTWARN 3
+#define BHARDWARN 4
+#define BSOFTLONGWARN 5
+#define BSOFTWARN 6
+
+/* Print warning to user which exceeded quota */
+static void print_warning(struct dquot *dquot, const char warntype)
+{
+	char *msg = NULL;
+	int flag = (warntype == BHARDWARN || warntype == BSOFTLONGWARN) ? DQ_BLKS_B :
+	  ((warntype == IHARDWARN || warntype == ISOFTLONGWARN) ? DQ_INODES_B : 0);
+
+	if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
+		return;
+
+	tty_write_message(current->signal->tty, dquot->dq_sb->s_id);
+	if (warntype == ISOFTWARN || warntype == BSOFTWARN)
+		tty_write_message(current->signal->tty, ": warning, ");
+	else
+		tty_write_message(current->signal->tty, ": write failed, ");
+	tty_write_message(current->signal->tty, quotatypes[dquot->dq_type]);
+	switch (warntype) {
+		case IHARDWARN:
+			msg = " file limit reached.\r\n";
+			break;
+		case ISOFTLONGWARN:
+			msg = " file quota exceeded too long.\r\n";
+			break;
+		case ISOFTWARN:
+			msg = " file quota exceeded.\r\n";
+			break;
+		case BHARDWARN:
+			msg = " block limit reached.\r\n";
+			break;
+		case BSOFTLONGWARN:
+			msg = " block quota exceeded too long.\r\n";
+			break;
+		case BSOFTWARN:
+			msg = " block quota exceeded.\r\n";
+			break;
+	}
+	tty_write_message(current->signal->tty, msg);
+}
+
+static inline void flush_warnings(struct dquot **dquots, char *warntype)
+{
+	int i;
+
+	for (i = 0; i < MAXQUOTAS; i++)
+		if (dquots[i] != NODQUOT && warntype[i] != NOWARN)
+			print_warning(dquots[i], warntype[i]);
+}
+
+static inline char 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, ulong inodes, char *warntype)
+{
+	*warntype = NOWARN;
+	if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
+		return QUOTA_OK;
+
+	if (dquot->dq_dqb.dqb_ihardlimit &&
+	   (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit &&
+            !ignore_hardlimit(dquot)) {
+		*warntype = IHARDWARN;
+		return NO_QUOTA;
+	}
+
+	if (dquot->dq_dqb.dqb_isoftlimit &&
+	   (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
+	    dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime &&
+            !ignore_hardlimit(dquot)) {
+		*warntype = ISOFTLONGWARN;
+		return NO_QUOTA;
+	}
+
+	if (dquot->dq_dqb.dqb_isoftlimit &&
+	   (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit &&
+	    dquot->dq_dqb.dqb_itime == 0) {
+		*warntype = ISOFTWARN;
+		dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace;
+	}
+
+	return QUOTA_OK;
+}
+
+/* needs dq_data_lock */
+static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
+{
+	*warntype = 0;
+	if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
+		return QUOTA_OK;
+
+	if (dquot->dq_dqb.dqb_bhardlimit &&
+	   toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit &&
+            !ignore_hardlimit(dquot)) {
+		if (!prealloc)
+			*warntype = BHARDWARN;
+		return NO_QUOTA;
+	}
+
+	if (dquot->dq_dqb.dqb_bsoftlimit &&
+	   toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
+	    dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime &&
+            !ignore_hardlimit(dquot)) {
+		if (!prealloc)
+			*warntype = BSOFTLONGWARN;
+		return NO_QUOTA;
+	}
+
+	if (dquot->dq_dqb.dqb_bsoftlimit &&
+	   toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
+	    dquot->dq_dqb.dqb_btime == 0) {
+		if (!prealloc) {
+			*warntype = BSOFTWARN;
+			dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace;
+		}
+		else
+			/*
+			 * We don't allow preallocation to exceed softlimit so exceeding will
+			 * be always printed
+			 */
+			return NO_QUOTA;
+	}
+
+	return QUOTA_OK;
+}
+
+/*
+ *	Initialize quota pointers in inode
+ *	Transaction must be started at entry
+ */
+int dquot_initialize(struct inode *inode, int type)
+{
+	unsigned int id = 0;
+	int cnt, ret = 0;
+
+	/* First test before acquiring semaphore - solves deadlocks when we
+         * re-enter the quota code and are already holding the semaphore */
+	if (IS_NOQUOTA(inode))
+		return 0;
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	/* Having dqptr_sem we know NOQUOTA flags can't be altered... */
+	if (IS_NOQUOTA(inode))
+		goto out_err;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		if (inode->i_dquot[cnt] == NODQUOT) {
+			switch (cnt) {
+				case USRQUOTA:
+					id = inode->i_uid;
+					break;
+				case GRPQUOTA:
+					id = inode->i_gid;
+					break;
+			}
+			inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
+		}
+	}
+out_err:
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return ret;
+}
+
+/*
+ * 	Release all quotas referenced by inode
+ *	Transaction must be started at an entry
+ */
+int dquot_drop(struct inode *inode)
+{
+	int cnt;
+
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] != NODQUOT) {
+			dqput(inode->i_dquot[cnt]);
+			inode->i_dquot[cnt] = NODQUOT;
+		}
+	}
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return 0;
+}
+
+/*
+ * Following four functions update 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 macros 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 warn)
+{
+	int cnt, ret = NO_QUOTA;
+	char warntype[MAXQUOTAS];
+
+	/* First test before acquiring semaphore - solves deadlocks when we
+         * re-enter the quota code and are already holding the semaphore */
+	if (IS_NOQUOTA(inode)) {
+out_add:
+		inode_add_bytes(inode, number);
+		return QUOTA_OK;
+	}
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		warntype[cnt] = NOWARN;
+
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	if (IS_NOQUOTA(inode)) {	/* Now we can do reliable test... */
+		up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		goto out_add;
+	}
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] == NODQUOT)
+			continue;
+		if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA)
+			goto warn_put_all;
+	}
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] == NODQUOT)
+			continue;
+		dquot_incr_space(inode->i_dquot[cnt], number);
+	}
+	inode_add_bytes(inode, number);
+	ret = QUOTA_OK;
+warn_put_all:
+	spin_unlock(&dq_data_lock);
+	if (ret == QUOTA_OK)
+		/* Dirtify all the dquots - this can block when journalling */
+		for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+			if (inode->i_dquot[cnt])
+				mark_dquot_dirty(inode->i_dquot[cnt]);
+	flush_warnings(inode->i_dquot, warntype);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return ret;
+}
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_alloc_inode(const struct inode *inode, unsigned long number)
+{
+	int cnt, ret = NO_QUOTA;
+	char warntype[MAXQUOTAS];
+
+	/* First test before acquiring semaphore - solves deadlocks when we
+         * re-enter the quota code and are already holding the semaphore */
+	if (IS_NOQUOTA(inode))
+		return QUOTA_OK;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		warntype[cnt] = NOWARN;
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	if (IS_NOQUOTA(inode)) {
+		up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		return QUOTA_OK;
+	}
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] == NODQUOT)
+			continue;
+		if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA)
+			goto warn_put_all;
+	}
+
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] == NODQUOT)
+			continue;
+		dquot_incr_inodes(inode->i_dquot[cnt], number);
+	}
+	ret = QUOTA_OK;
+warn_put_all:
+	spin_unlock(&dq_data_lock);
+	if (ret == QUOTA_OK)
+		/* Dirtify all the dquots - this can block when journalling */
+		for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+			if (inode->i_dquot[cnt])
+				mark_dquot_dirty(inode->i_dquot[cnt]);
+	flush_warnings((struct dquot **)inode->i_dquot, warntype);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return ret;
+}
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_free_space(struct inode *inode, qsize_t number)
+{
+	unsigned int cnt;
+
+	/* First test before acquiring semaphore - solves deadlocks when we
+         * re-enter the quota code and are already holding the semaphore */
+	if (IS_NOQUOTA(inode)) {
+out_sub:
+		inode_sub_bytes(inode, number);
+		return QUOTA_OK;
+	}
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	/* Now recheck reliably when holding dqptr_sem */
+	if (IS_NOQUOTA(inode)) {
+		up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		goto out_sub;
+	}
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] == NODQUOT)
+			continue;
+		dquot_decr_space(inode->i_dquot[cnt], number);
+	}
+	inode_sub_bytes(inode, number);
+	spin_unlock(&dq_data_lock);
+	/* Dirtify all the dquots - this can block when journalling */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if (inode->i_dquot[cnt])
+			mark_dquot_dirty(inode->i_dquot[cnt]);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return QUOTA_OK;
+}
+
+/*
+ * This operation can block, but only after everything is updated
+ */
+int dquot_free_inode(const struct inode *inode, unsigned long number)
+{
+	unsigned int cnt;
+
+	/* First test before acquiring semaphore - solves deadlocks when we
+         * re-enter the quota code and are already holding the semaphore */
+	if (IS_NOQUOTA(inode))
+		return QUOTA_OK;
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	/* Now recheck reliably when holding dqptr_sem */
+	if (IS_NOQUOTA(inode)) {
+		up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		return QUOTA_OK;
+	}
+	spin_lock(&dq_data_lock);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt] == NODQUOT)
+			continue;
+		dquot_decr_inodes(inode->i_dquot[cnt], number);
+	}
+	spin_unlock(&dq_data_lock);
+	/* Dirtify all the dquots - this can block when journalling */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		if (inode->i_dquot[cnt])
+			mark_dquot_dirty(inode->i_dquot[cnt]);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return QUOTA_OK;
+}
+
+/*
+ * Transfer the number of inode and blocks from one diskquota to an other.
+ *
+ * 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 iattr *iattr)
+{
+	qsize_t space;
+	struct dquot *transfer_from[MAXQUOTAS];
+	struct dquot *transfer_to[MAXQUOTAS];
+	int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
+	    chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
+	char warntype[MAXQUOTAS];
+
+	/* First test before acquiring semaphore - solves deadlocks when we
+         * re-enter the quota code and are already holding the semaphore */
+	if (IS_NOQUOTA(inode))
+		return QUOTA_OK;
+	/* Clear the arrays */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
+		warntype[cnt] = NOWARN;
+	}
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	/* Now recheck reliably when holding dqptr_sem */
+	if (IS_NOQUOTA(inode)) {	/* File without quota accounting? */
+		up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		return QUOTA_OK;
+	}
+	/* First build the transfer_to list - here we can block on
+	 * reading/instantiating of dquots.  We know that the transaction for
+	 * us was already started so we don't violate lock ranking here */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		switch (cnt) {
+			case USRQUOTA:
+				if (!chuid)
+					continue;
+				transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt);
+				break;
+			case GRPQUOTA:
+				if (!chgid)
+					continue;
+				transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt);
+				break;
+		}
+	}
+	spin_lock(&dq_data_lock);
+	space = inode_get_bytes(inode);
+	/* Build the transfer_from list and check the limits */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (transfer_to[cnt] == NODQUOT)
+			continue;
+		transfer_from[cnt] = inode->i_dquot[cnt];
+		if (check_idq(transfer_to[cnt], 1, warntype+cnt) == NO_QUOTA ||
+		    check_bdq(transfer_to[cnt], space, 0, warntype+cnt) == NO_QUOTA)
+			goto warn_put_all;
+	}
+
+	/*
+	 * 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] == NODQUOT)
+			continue;
+
+		/* Due to IO error we might not have transfer_from[] structure */
+		if (transfer_from[cnt]) {
+			dquot_decr_inodes(transfer_from[cnt], 1);
+			dquot_decr_space(transfer_from[cnt], space);
+		}
+
+		dquot_incr_inodes(transfer_to[cnt], 1);
+		dquot_incr_space(transfer_to[cnt], space);
+
+		inode->i_dquot[cnt] = transfer_to[cnt];
+	}
+	ret = QUOTA_OK;
+warn_put_all:
+	spin_unlock(&dq_data_lock);
+	/* Dirtify all the dquots - this can block when journalling */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (transfer_from[cnt])
+			mark_dquot_dirty(transfer_from[cnt]);
+		if (transfer_to[cnt])
+			mark_dquot_dirty(transfer_to[cnt]);
+	}
+	flush_warnings(transfer_to, warntype);
+	
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
+			dqput(transfer_from[cnt]);
+		if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
+			dqput(transfer_to[cnt]);
+	}
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return ret;
+}
+
+/*
+ * 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);
+
+	down(&dqopt->dqio_sem);
+	ret = dqopt->ops[type]->write_file_info(sb, type);
+	up(&dqopt->dqio_sem);
+	return ret;
+}
+
+/*
+ * Definitions of diskquota operations.
+ */
+struct dquot_operations dquot_operations = {
+	.initialize	= dquot_initialize,
+	.drop		= dquot_drop,
+	.alloc_space	= dquot_alloc_space,
+	.alloc_inode	= dquot_alloc_inode,
+	.free_space	= dquot_free_space,
+	.free_inode	= dquot_free_inode,
+	.transfer	= dquot_transfer,
+	.write_dquot	= dquot_commit,
+	.acquire_dquot	= dquot_acquire,
+	.release_dquot	= dquot_release,
+	.mark_dirty	= dquot_mark_dquot_dirty,
+	.write_info	= dquot_commit_info
+};
+
+static inline void set_enable_flags(struct quota_info *dqopt, int type)
+{
+	switch (type) {
+		case USRQUOTA:
+			dqopt->flags |= DQUOT_USR_ENABLED;
+			break;
+		case GRPQUOTA:
+			dqopt->flags |= DQUOT_GRP_ENABLED;
+			break;
+	}
+}
+
+static inline void reset_enable_flags(struct quota_info *dqopt, int type)
+{
+	switch (type) {
+		case USRQUOTA:
+			dqopt->flags &= ~DQUOT_USR_ENABLED;
+			break;
+		case GRPQUOTA:
+			dqopt->flags &= ~DQUOT_GRP_ENABLED;
+			break;
+	}
+}
+
+/*
+ * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
+ */
+int vfs_quota_off(struct super_block *sb, int type)
+{
+	int cnt;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	struct inode *toputinode[MAXQUOTAS];
+	struct vfsmount *toputmnt[MAXQUOTAS];
+
+	/* We need to serialize quota_off() for device */
+	down(&dqopt->dqonoff_sem);
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		toputinode[cnt] = NULL;
+		toputmnt[cnt] = NULL;
+		if (type != -1 && cnt != type)
+			continue;
+		if (!sb_has_quota_enabled(sb, cnt))
+			continue;
+		reset_enable_flags(dqopt, cnt);
+
+		/* 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];
+		toputmnt[cnt] = dqopt->mnt[cnt];
+		dqopt->files[cnt] = NULL;
+		dqopt->mnt[cnt] = NULL;
+		dqopt->info[cnt].dqi_flags = 0;
+		dqopt->info[cnt].dqi_igrace = 0;
+		dqopt->info[cnt].dqi_bgrace = 0;
+		dqopt->ops[cnt] = NULL;
+	}
+	up(&dqopt->dqonoff_sem);
+	/* Sync the superblock so that buffers with quota data are written to
+	 * disk (and so userspace sees correct data afterwards).
+	 * The reference to vfsmnt we are still holding protects us from
+	 * umount (we don't have it only when quotas are turned on/off for
+	 * journal replay but in that case we are guarded by the fs anyway). */
+	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]) {
+			down(&dqopt->dqonoff_sem);
+			/* If quota was reenabled in the meantime, we have
+			 * nothing to do */
+			if (!sb_has_quota_enabled(sb, cnt)) {
+				down(&toputinode[cnt]->i_sem);
+				toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
+				  S_NOATIME | S_NOQUOTA);
+				truncate_inode_pages(&toputinode[cnt]->i_data, 0);
+				up(&toputinode[cnt]->i_sem);
+				mark_inode_dirty(toputinode[cnt]);
+				iput(toputinode[cnt]);
+			}
+			up(&dqopt->dqonoff_sem);
+			/* We don't hold the reference when we turned on quotas
+			 * just for the journal replay... */
+			if (toputmnt[cnt])
+				mntput(toputmnt[cnt]);
+		}
+	if (sb->s_bdev)
+		invalidate_bdev(sb->s_bdev, 0);
+	return 0;
+}
+
+/*
+ *	Turn quotas on on a device
+ */
+
+/* Helper function when we already have the inode */
+static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
+{
+	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;
+	}
+
+	/* As we bypass the pagecache we must now flush the inode so that
+	 * we see all the changes from userspace... */
+	write_inode_now(inode, 1);
+	/* And now flush the block cache so that kernel sees the changes */
+	invalidate_bdev(sb->s_bdev, 0);
+	down(&inode->i_sem);
+	down(&dqopt->dqonoff_sem);
+	if (sb_has_quota_enabled(sb, type)) {
+		error = -EBUSY;
+		goto out_lock;
+	}
+	/* 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. */
+	down_write(&dqopt->dqptr_sem);
+	oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA);
+	inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
+	up_write(&dqopt->dqptr_sem);
+
+	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;
+	INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
+	down(&dqopt->dqio_sem);
+	if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
+		up(&dqopt->dqio_sem);
+		goto out_file_init;
+	}
+	up(&dqopt->dqio_sem);
+	up(&inode->i_sem);
+	set_enable_flags(dqopt, type);
+
+	add_dquot_ref(sb, type);
+	up(&dqopt->dqonoff_sem);
+
+	return 0;
+
+out_file_init:
+	dqopt->files[type] = NULL;
+	iput(inode);
+out_lock:
+	up(&dqopt->dqonoff_sem);
+	if (oldflags != -1) {
+		down_write(&dqopt->dqptr_sem);
+		/* 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;
+		up_write(&dqopt->dqptr_sem);
+	}
+	up(&inode->i_sem);
+out_fmt:
+	put_quota_format(fmt);
+
+	return error; 
+}
+
+/* Actual function called from quotactl() */
+int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
+{
+	struct nameidata nd;
+	int error;
+
+	error = path_lookup(path, LOOKUP_FOLLOW, &nd);
+	if (error < 0)
+		return error;
+	error = security_quota_on(nd.dentry);
+	if (error)
+		goto out_path;
+	/* Quota file not on the same filesystem? */
+	if (nd.mnt->mnt_sb != sb)
+		error = -EXDEV;
+	else {
+		error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
+		if (!error)
+			sb_dqopt(sb)->mnt[type] = mntget(nd.mnt);
+	}
+out_path:
+	path_release(&nd);
+	return error;
+}
+
+/*
+ * This function is used when filesystem needs to initialize quotas
+ * during mount time.
+ */
+int vfs_quota_on_mount(int type, int format_id, struct dentry *dentry)
+{
+	int error;
+
+	error = security_quota_on(dentry);
+	if (error)
+		return error;
+	return vfs_quota_on_inode(dentry->d_inode, type, format_id);
+}
+
+/* Generic routine for getting common part of quota structure */
+static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di)
+{
+	struct mem_dqblk *dm = &dquot->dq_dqb;
+
+	spin_lock(&dq_data_lock);
+	di->dqb_bhardlimit = dm->dqb_bhardlimit;
+	di->dqb_bsoftlimit = dm->dqb_bsoftlimit;
+	di->dqb_curspace = dm->dqb_curspace;
+	di->dqb_ihardlimit = dm->dqb_ihardlimit;
+	di->dqb_isoftlimit = dm->dqb_isoftlimit;
+	di->dqb_curinodes = dm->dqb_curinodes;
+	di->dqb_btime = dm->dqb_btime;
+	di->dqb_itime = dm->dqb_itime;
+	di->dqb_valid = QIF_ALL;
+	spin_unlock(&dq_data_lock);
+}
+
+int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
+{
+	struct dquot *dquot;
+
+	down(&sb_dqopt(sb)->dqonoff_sem);
+	if (!(dquot = dqget(sb, id, type))) {
+		up(&sb_dqopt(sb)->dqonoff_sem);
+		return -ESRCH;
+	}
+	do_get_dqblk(dquot, di);
+	dqput(dquot);
+	up(&sb_dqopt(sb)->dqonoff_sem);
+	return 0;
+}
+
+/* Generic routine for setting common part of quota structure */
+static void do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
+{
+	struct mem_dqblk *dm = &dquot->dq_dqb;
+	int check_blim = 0, check_ilim = 0;
+
+	spin_lock(&dq_data_lock);
+	if (di->dqb_valid & QIF_SPACE) {
+		dm->dqb_curspace = di->dqb_curspace;
+		check_blim = 1;
+	}
+	if (di->dqb_valid & QIF_BLIMITS) {
+		dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
+		dm->dqb_bhardlimit = di->dqb_bhardlimit;
+		check_blim = 1;
+	}
+	if (di->dqb_valid & QIF_INODES) {
+		dm->dqb_curinodes = di->dqb_curinodes;
+		check_ilim = 1;
+	}
+	if (di->dqb_valid & QIF_ILIMITS) {
+		dm->dqb_isoftlimit = di->dqb_isoftlimit;
+		dm->dqb_ihardlimit = di->dqb_ihardlimit;
+		check_ilim = 1;
+	}
+	if (di->dqb_valid & QIF_BTIME)
+		dm->dqb_btime = di->dqb_btime;
+	if (di->dqb_valid & QIF_ITIME)
+		dm->dqb_itime = di->dqb_itime;
+
+	if (check_blim) {
+		if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
+			dm->dqb_btime = 0;
+			clear_bit(DQ_BLKS_B, &dquot->dq_flags);
+		}
+		else if (!(di->dqb_valid & QIF_BTIME))	/* Set grace only if user hasn't provided his own... */
+			dm->dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].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->dqb_valid & QIF_ITIME))	/* Set grace only if user hasn't provided his own... */
+			dm->dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].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);
+}
+
+int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di)
+{
+	struct dquot *dquot;
+
+	down(&sb_dqopt(sb)->dqonoff_sem);
+	if (!(dquot = dqget(sb, id, type))) {
+		up(&sb_dqopt(sb)->dqonoff_sem);
+		return -ESRCH;
+	}
+	do_set_dqblk(dquot, di);
+	dqput(dquot);
+	up(&sb_dqopt(sb)->dqonoff_sem);
+	return 0;
+}
+
+/* Generic routine for getting common part of quota file information */
+int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+{
+	struct mem_dqinfo *mi;
+  
+	down(&sb_dqopt(sb)->dqonoff_sem);
+	if (!sb_has_quota_enabled(sb, type)) {
+		up(&sb_dqopt(sb)->dqonoff_sem);
+		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);
+	up(&sb_dqopt(sb)->dqonoff_sem);
+	return 0;
+}
+
+/* Generic routine for setting common part of quota file information */
+int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+{
+	struct mem_dqinfo *mi;
+
+	down(&sb_dqopt(sb)->dqonoff_sem);
+	if (!sb_has_quota_enabled(sb, type)) {
+		up(&sb_dqopt(sb)->dqonoff_sem);
+		return -ESRCH;
+	}
+	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);
+	up(&sb_dqopt(sb)->dqonoff_sem);
+	return 0;
+}
+
+struct quotactl_ops vfs_quotactl_ops = {
+	.quota_on	= vfs_quota_on,
+	.quota_off	= vfs_quota_off,
+	.quota_sync	= vfs_quota_sync,
+	.get_info	= vfs_get_dqinfo,
+	.set_info	= vfs_set_dqinfo,
+	.get_dqblk	= vfs_get_dqblk,
+	.set_dqblk	= vfs_set_dqblk
+};
+
+static ctl_table fs_dqstats_table[] = {
+	{
+		.ctl_name	= FS_DQ_LOOKUPS,
+		.procname	= "lookups",
+		.data		= &dqstats.lookups,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_DROPS,
+		.procname	= "drops",
+		.data		= &dqstats.drops,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_READS,
+		.procname	= "reads",
+		.data		= &dqstats.reads,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_WRITES,
+		.procname	= "writes",
+		.data		= &dqstats.writes,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_CACHE_HITS,
+		.procname	= "cache_hits",
+		.data		= &dqstats.cache_hits,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_ALLOCATED,
+		.procname	= "allocated_dquots",
+		.data		= &dqstats.allocated_dquots,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_FREE,
+		.procname	= "free_dquots",
+		.data		= &dqstats.free_dquots,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_SYNCS,
+		.procname	= "syncs",
+		.data		= &dqstats.syncs,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= FS_DQ_WARNINGS,
+		.procname	= "warnings",
+		.data		= &flag_print_warnings,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{ .ctl_name = 0 },
+};
+
+static ctl_table fs_table[] = {
+	{
+		.ctl_name	= FS_DQSTATS,
+		.procname	= "quota",
+		.mode		= 0555,
+		.child		= fs_dqstats_table,
+	},
+	{ .ctl_name = 0 },
+};
+
+static ctl_table sys_table[] = {
+	{
+		.ctl_name	= CTL_FS,
+		.procname	= "fs",
+		.mode		= 0555,
+		.child		= fs_table,
+	},
+	{ .ctl_name = 0 },
+};
+
+static int __init dquot_init(void)
+{
+	int i;
+	unsigned long nr_hash, order;
+
+	printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
+
+	register_sysctl_table(sys_table, 0);
+
+	dquot_cachep = kmem_cache_create("dquot", 
+			sizeof(struct dquot), sizeof(unsigned long) * 4,
+			SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_PANIC,
+			NULL, NULL);
+
+	order = 0;
+	dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order);
+	if (!dquot_hash)
+		panic("Cannot create dquot hash table");
+
+	/* 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));
+
+	set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);
+
+	return 0;
+}
+module_init(dquot_init);
+
+EXPORT_SYMBOL(register_quota_format);
+EXPORT_SYMBOL(unregister_quota_format);
+EXPORT_SYMBOL(dqstats);
+EXPORT_SYMBOL(dq_data_lock);
+EXPORT_SYMBOL(vfs_quota_on);
+EXPORT_SYMBOL(vfs_quota_on_mount);
+EXPORT_SYMBOL(vfs_quota_off);
+EXPORT_SYMBOL(vfs_quota_sync);
+EXPORT_SYMBOL(vfs_get_dqinfo);
+EXPORT_SYMBOL(vfs_set_dqinfo);
+EXPORT_SYMBOL(vfs_get_dqblk);
+EXPORT_SYMBOL(vfs_set_dqblk);
+EXPORT_SYMBOL(dquot_commit);
+EXPORT_SYMBOL(dquot_commit_info);
+EXPORT_SYMBOL(dquot_acquire);
+EXPORT_SYMBOL(dquot_release);
+EXPORT_SYMBOL(dquot_mark_dquot_dirty);
+EXPORT_SYMBOL(dquot_initialize);
+EXPORT_SYMBOL(dquot_drop);
+EXPORT_SYMBOL(dquot_alloc_space);
+EXPORT_SYMBOL(dquot_alloc_inode);
+EXPORT_SYMBOL(dquot_free_space);
+EXPORT_SYMBOL(dquot_free_inode);
+EXPORT_SYMBOL(dquot_transfer);