6 files changed, 735 insertions, 570 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index b93425ad15de..c1ce3d8831d8 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -302,6 +302,10 @@ config PRINT_QUOTA_WARNING
           Note that this behavior is currently deprecated and may go away in
           future. Please use notification via netlink socket instead.
 
+# Generic support for tree structured quota files. Seleted when needed.
+config QUOTA_TREE
+         tristate
+
 config QFMT_V1
         tristate "Old quota format support"
         depends on QUOTA
@@ -313,6 +317,7 @@ config QFMT_V1
 config QFMT_V2
         tristate "Quota format v2 support"
         depends on QUOTA
+        select QUOTA_TREE
         help
           This quota format allows using quotas with 32-bit UIDs/GIDs. If you
           need this functionality say Y here.
diff --git a/fs/Makefile b/fs/Makefile
index e6f423d1d228..c830611550d3 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_GENERIC_ACL)	+= generic_acl.o
 obj-$(CONFIG_QUOTA)             += dquot.o
 obj-$(CONFIG_QFMT_V1)           += quota_v1.o
 obj-$(CONFIG_QFMT_V2)           += quota_v2.o
+obj-$(CONFIG_QUOTA_TREE)        += quota_tree.o
 obj-$(CONFIG_QUOTACTL)          += quota.o
 
 obj-$(CONFIG_PROC_FS)           += proc/
diff --git a/fs/quota_tree.c b/fs/quota_tree.c
new file mode 100644
index 000000000000..953404c95b17
--- /dev/null
+++ b/fs/quota_tree.c
@@ -0,0 +1,645 @@
+/*
+ *      vfsv0 quota IO operations on file
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/dqblk_v2.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/quotaops.h>
+
+#include <asm/byteorder.h>
+
+#include "quota_tree.h"
+
+MODULE_AUTHOR("Jan Kara");
+MODULE_DESCRIPTION("Quota trie support");
+MODULE_LICENSE("GPL");
+
+#define __QUOTA_QT_PARANOIA
+
+typedef char *dqbuf_t;
+
+static int get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
+{
+        unsigned int epb = info->dqi_usable_bs >> 2;
+
+        depth = info->dqi_qtree_depth - depth - 1;
+        while (depth--)
+                id /= epb;
+        return id % epb;
+}
+
+/* Number of entries in one blocks */
+static inline int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
+{
+        return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader))
+               / info->dqi_entry_size;
+}
+
+static dqbuf_t getdqbuf(size_t size)
+{
+        dqbuf_t buf = kmalloc(size, GFP_NOFS);
+        if (!buf)
+                printk(KERN_WARNING "VFS: Not enough memory for quota buffers.\n");
+        return buf;
+}
+
+static inline void freedqbuf(dqbuf_t buf)
+{
+        kfree(buf);
+}
+
+static inline ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, dqbuf_t buf)
+{
+        struct super_block *sb = info->dqi_sb;
+
+        memset(buf, 0, info->dqi_usable_bs);
+        return sb->s_op->quota_read(sb, info->dqi_type, (char *)buf,
+               info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
+}
+
+static inline ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, dqbuf_t buf)
+{
+        struct super_block *sb = info->dqi_sb;
+
+        return sb->s_op->quota_write(sb, info->dqi_type, (char *)buf,
+               info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
+}
+
+/* Remove empty block from list and return it */
+static int get_free_dqblk(struct qtree_mem_dqinfo *info)
+{
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
+        int ret, blk;
+
+        if (!buf)
+                return -ENOMEM;
+        if (info->dqi_free_blk) {
+                blk = info->dqi_free_blk;
+                ret = read_blk(info, blk, buf);
+                if (ret < 0)
+                        goto out_buf;
+                info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
+        }
+        else {
+                memset(buf, 0, info->dqi_usable_bs);
+                /* Assure block allocation... */
+                ret = write_blk(info, info->dqi_blocks, buf);
+                if (ret < 0)
+                        goto out_buf;
+                blk = info->dqi_blocks++;
+        }
+        mark_info_dirty(info->dqi_sb, info->dqi_type);
+        ret = blk;
+out_buf:
+        freedqbuf(buf);
+        return ret;
+}
+
+/* Insert empty block to the list */
+static int put_free_dqblk(struct qtree_mem_dqinfo *info, dqbuf_t buf, uint blk)
+{
+        struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
+        int err;
+
+        dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
+        dh->dqdh_prev_free = cpu_to_le32(0);
+        dh->dqdh_entries = cpu_to_le16(0);
+        err = write_blk(info, blk, buf);
+        if (err < 0)
+                return err;
+        info->dqi_free_blk = blk;
+        mark_info_dirty(info->dqi_sb, info->dqi_type);
+        return 0;
+}
+
+/* Remove given block from the list of blocks with free entries */
+static int remove_free_dqentry(struct qtree_mem_dqinfo *info, dqbuf_t buf, uint blk)
+{
+        dqbuf_t tmpbuf = getdqbuf(info->dqi_usable_bs);
+        struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
+        uint nextblk = le32_to_cpu(dh->dqdh_next_free);
+        uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
+        int err;
+
+        if (!tmpbuf)
+                return -ENOMEM;
+        if (nextblk) {
+                err = read_blk(info, nextblk, tmpbuf);
+                if (err < 0)
+                        goto out_buf;
+                ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
+                                                        dh->dqdh_prev_free;
+                err = write_blk(info, nextblk, tmpbuf);
+                if (err < 0)
+                        goto out_buf;
+        }
+        if (prevblk) {
+                err = read_blk(info, prevblk, tmpbuf);
+                if (err < 0)
+                        goto out_buf;
+                ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
+                                                        dh->dqdh_next_free;
+                err = write_blk(info, prevblk, tmpbuf);
+                if (err < 0)
+                        goto out_buf;
+        } else {
+                info->dqi_free_entry = nextblk;
+                mark_info_dirty(info->dqi_sb, info->dqi_type);
+        }
+        freedqbuf(tmpbuf);
+        dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
+        /* No matter whether write succeeds block is out of list */
+        if (write_blk(info, blk, buf) < 0)
+                printk(KERN_ERR "VFS: Can't write block (%u) with free entries.\n", blk);
+        return 0;
+out_buf:
+        freedqbuf(tmpbuf);
+        return err;
+}
+
+/* Insert given block to the beginning of list with free entries */
+static int insert_free_dqentry(struct qtree_mem_dqinfo *info, dqbuf_t buf, uint blk)
+{
+        dqbuf_t tmpbuf = getdqbuf(info->dqi_usable_bs);
+        struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
+        int err;
+
+        if (!tmpbuf)
+                return -ENOMEM;
+        dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
+        dh->dqdh_prev_free = cpu_to_le32(0);
+        err = write_blk(info, blk, buf);
+        if (err < 0)
+                goto out_buf;
+        if (info->dqi_free_entry) {
+                err = read_blk(info, info->dqi_free_entry, tmpbuf);
+                if (err < 0)
+                        goto out_buf;
+                ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
+                                                        cpu_to_le32(blk);
+                err = write_blk(info, info->dqi_free_entry, tmpbuf);
+                if (err < 0)
+                        goto out_buf;
+        }
+        freedqbuf(tmpbuf);
+        info->dqi_free_entry = blk;
+        mark_info_dirty(info->dqi_sb, info->dqi_type);
+        return 0;
+out_buf:
+        freedqbuf(tmpbuf);
+        return err;
+}
+
+/* Is the entry in the block free? */
+int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
+{
+        int i;
+
+        for (i = 0; i < info->dqi_entry_size; i++)
+                if (disk[i])
+                        return 0;
+        return 1;
+}
+EXPORT_SYMBOL(qtree_entry_unused);
+
+/* Find space for dquot */
+static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
+                              struct dquot *dquot, int *err)
+{
+        uint blk, i;
+        struct qt_disk_dqdbheader *dh;
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        char *ddquot;
+
+        *err = 0;
+        if (!buf) {
+                *err = -ENOMEM;
+                return 0;
+        }
+        dh = (struct qt_disk_dqdbheader *)buf;
+        if (info->dqi_free_entry) {
+                blk = info->dqi_free_entry;
+                *err = read_blk(info, blk, buf);
+                if (*err < 0)
+                        goto out_buf;
+        } else {
+                blk = get_free_dqblk(info);
+                if ((int)blk < 0) {
+                        *err = blk;
+                        freedqbuf(buf);
+                        return 0;
+                }
+                memset(buf, 0, info->dqi_usable_bs);
+                /* This is enough as block is already zeroed and entry list is empty... */
+                info->dqi_free_entry = blk;
+                mark_info_dirty(dquot->dq_sb, dquot->dq_type);
+        }
+        /* Block will be full? */
+        if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
+                *err = remove_free_dqentry(info, buf, blk);
+                if (*err < 0) {
+                        printk(KERN_ERR "VFS: find_free_dqentry(): Can't "
+                               "remove block (%u) from entry free list.\n",
+                               blk);
+                        goto out_buf;
+                }
+        }
+        le16_add_cpu(&dh->dqdh_entries, 1);
+        /* Find free structure in block */
+        for (i = 0, ddquot = ((char *)buf) + sizeof(struct qt_disk_dqdbheader);
+             i < qtree_dqstr_in_blk(info) && !qtree_entry_unused(info, ddquot);
+             i++, ddquot += info->dqi_entry_size);
+#ifdef __QUOTA_QT_PARANOIA
+        if (i == qtree_dqstr_in_blk(info)) {
+                printk(KERN_ERR "VFS: find_free_dqentry(): Data block full "
+                                "but it shouldn't.\n");
+                *err = -EIO;
+                goto out_buf;
+        }
+#endif
+        *err = write_blk(info, blk, buf);
+        if (*err < 0) {
+                printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota "
+                                "data block %u.\n", blk);
+                goto out_buf;
+        }
+        dquot->dq_off = (blk << info->dqi_blocksize_bits) +
+                        sizeof(struct qt_disk_dqdbheader) +
+                        i * info->dqi_entry_size;
+        freedqbuf(buf);
+        return blk;
+out_buf:
+        freedqbuf(buf);
+        return 0;
+}
+
+/* Insert reference to structure into the trie */
+static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
+                          uint *treeblk, int depth)
+{
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        int ret = 0, newson = 0, newact = 0;
+        __le32 *ref;
+        uint newblk;
+
+        if (!buf)
+                return -ENOMEM;
+        if (!*treeblk) {
+                ret = get_free_dqblk(info);
+                if (ret < 0)
+                        goto out_buf;
+                *treeblk = ret;
+                memset(buf, 0, info->dqi_usable_bs);
+                newact = 1;
+        } else {
+                ret = read_blk(info, *treeblk, buf);
+                if (ret < 0) {
+                        printk(KERN_ERR "VFS: Can't read tree quota block "
+                                        "%u.\n", *treeblk);
+                        goto out_buf;
+                }
+        }
+        ref = (__le32 *)buf;
+        newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
+        if (!newblk)
+                newson = 1;
+        if (depth == info->dqi_qtree_depth - 1) {
+#ifdef __QUOTA_QT_PARANOIA
+                if (newblk) {
+                        printk(KERN_ERR "VFS: Inserting already present quota "
+                                        "entry (block %u).\n",
+                               le32_to_cpu(ref[get_index(info,
+                                                dquot->dq_id, depth)]));
+                        ret = -EIO;
+                        goto out_buf;
+                }
+#endif
+                newblk = find_free_dqentry(info, dquot, &ret);
+        } else {
+                ret = do_insert_tree(info, dquot, &newblk, depth+1);
+        }
+        if (newson && ret >= 0) {
+                ref[get_index(info, dquot->dq_id, depth)] =
+                                                        cpu_to_le32(newblk);
+                ret = write_blk(info, *treeblk, buf);
+        } else if (newact && ret < 0) {
+                put_free_dqblk(info, buf, *treeblk);
+        }
+out_buf:
+        freedqbuf(buf);
+        return ret;
+}
+
+/* Wrapper for inserting quota structure into tree */
+static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
+                                 struct dquot *dquot)
+{
+        int tmp = QT_TREEOFF;
+        return do_insert_tree(info, dquot, &tmp, 0);
+}
+
+/*
+ *      We don't have to be afraid of deadlocks as we never have quotas on quota files...
+ */
+int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
+{
+        int type = dquot->dq_type;
+        struct super_block *sb = dquot->dq_sb;
+        ssize_t ret;
+        dqbuf_t ddquot = getdqbuf(info->dqi_entry_size);
+
+        if (!ddquot)
+                return -ENOMEM;
+
+        /* dq_off is guarded by dqio_mutex */
+        if (!dquot->dq_off) {
+                ret = dq_insert_tree(info, dquot);
+                if (ret < 0) {
+                        printk(KERN_ERR "VFS: Error %zd occurred while "
+                                        "creating quota.\n", ret);
+                        freedqbuf(ddquot);
+                        return ret;
+                }
+        }
+        spin_lock(&dq_data_lock);
+        info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
+        spin_unlock(&dq_data_lock);
+        ret = sb->s_op->quota_write(sb, type, (char *)ddquot,
+                                        info->dqi_entry_size, dquot->dq_off);
+        if (ret != info->dqi_entry_size) {
+                printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
+                       sb->s_id);
+                if (ret >= 0)
+                        ret = -ENOSPC;
+        } else {
+                ret = 0;
+        }
+        dqstats.writes++;
+        freedqbuf(ddquot);
+
+        return ret;
+}
+EXPORT_SYMBOL(qtree_write_dquot);
+
+/* Free dquot entry in data block */
+static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
+                        uint blk)
+{
+        struct qt_disk_dqdbheader *dh;
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        int ret = 0;
+
+        if (!buf)
+                return -ENOMEM;
+        if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
+                printk(KERN_ERR "VFS: Quota structure has offset to other "
+                  "block (%u) than it should (%u).\n", blk,
+                  (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
+                goto out_buf;
+        }
+        ret = read_blk(info, blk, buf);
+        if (ret < 0) {
+                printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
+                goto out_buf;
+        }
+        dh = (struct qt_disk_dqdbheader *)buf;
+        le16_add_cpu(&dh->dqdh_entries, -1);
+        if (!le16_to_cpu(dh->dqdh_entries)) {   /* Block got free? */
+                ret = remove_free_dqentry(info, buf, blk);
+                if (ret >= 0)
+                        ret = put_free_dqblk(info, buf, blk);
+                if (ret < 0) {
+                        printk(KERN_ERR "VFS: Can't move quota data block (%u) "
+                          "to free list.\n", blk);
+                        goto out_buf;
+                }
+        } else {
+                memset(buf +
+                       (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
+                       0, info->dqi_entry_size);
+                if (le16_to_cpu(dh->dqdh_entries) ==
+                    qtree_dqstr_in_blk(info) - 1) {
+                        /* Insert will write block itself */
+                        ret = insert_free_dqentry(info, buf, blk);
+                        if (ret < 0) {
+                                printk(KERN_ERR "VFS: Can't insert quota data "
+                                       "block (%u) to free entry list.\n", blk);
+                                goto out_buf;
+                        }
+                } else {
+                        ret = write_blk(info, blk, buf);
+                        if (ret < 0) {
+                                printk(KERN_ERR "VFS: Can't write quota data "
+                                  "block %u\n", blk);
+                                goto out_buf;
+                        }
+                }
+        }
+        dquot->dq_off = 0;      /* Quota is now unattached */
+out_buf:
+        freedqbuf(buf);
+        return ret;
+}
+
+/* Remove reference to dquot from tree */
+static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
+                       uint *blk, int depth)
+{
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        int ret = 0;
+        uint newblk;
+        __le32 *ref = (__le32 *)buf;
+
+        if (!buf)
+                return -ENOMEM;
+        ret = read_blk(info, *blk, buf);
+        if (ret < 0) {
+                printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
+                goto out_buf;
+        }
+        newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
+        if (depth == info->dqi_qtree_depth - 1) {
+                ret = free_dqentry(info, dquot, newblk);
+                newblk = 0;
+        } else {
+                ret = remove_tree(info, dquot, &newblk, depth+1);
+        }
+        if (ret >= 0 && !newblk) {
+                int i;
+                ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
+                /* Block got empty? */
+                for (i = 0;
+                     i < (info->dqi_usable_bs >> 2) && !ref[i];
+                     i++);
+                /* Don't put the root block into the free block list */
+                if (i == (info->dqi_usable_bs >> 2)
+                    && *blk != QT_TREEOFF) {
+                        put_free_dqblk(info, buf, *blk);
+                        *blk = 0;
+                } else {
+                        ret = write_blk(info, *blk, buf);
+                        if (ret < 0)
+                                printk(KERN_ERR "VFS: Can't write quota tree "
+                                  "block %u.\n", *blk);
+                }
+        }
+out_buf:
+        freedqbuf(buf);
+        return ret;
+}
+
+/* Delete dquot from tree */
+int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
+{
+        uint tmp = QT_TREEOFF;
+
+        if (!dquot->dq_off)     /* Even not allocated? */
+                return 0;
+        return remove_tree(info, dquot, &tmp, 0);
+}
+EXPORT_SYMBOL(qtree_delete_dquot);
+
+/* Find entry in block */
+static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
+                                 struct dquot *dquot, uint blk)
+{
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        loff_t ret = 0;
+        int i;
+        char *ddquot;
+
+        if (!buf)
+                return -ENOMEM;
+        ret = read_blk(info, blk, buf);
+        if (ret < 0) {
+                printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
+                goto out_buf;
+        }
+        for (i = 0, ddquot = ((char *)buf) + sizeof(struct qt_disk_dqdbheader);
+             i < qtree_dqstr_in_blk(info) && !info->dqi_ops->is_id(ddquot, dquot);
+             i++, ddquot += info->dqi_entry_size);
+        if (i == qtree_dqstr_in_blk(info)) {
+                printk(KERN_ERR "VFS: Quota for id %u referenced "
+                  "but not present.\n", dquot->dq_id);
+                ret = -EIO;
+                goto out_buf;
+        } else {
+                ret = (blk << info->dqi_blocksize_bits) + sizeof(struct
+                  qt_disk_dqdbheader) + i * info->dqi_entry_size;
+        }
+out_buf:
+        freedqbuf(buf);
+        return ret;
+}
+
+/* Find entry for given id in the tree */
+static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
+                                struct dquot *dquot, uint blk, int depth)
+{
+        dqbuf_t buf = getdqbuf(info->dqi_usable_bs);
+        loff_t ret = 0;
+        __le32 *ref = (__le32 *)buf;
+
+        if (!buf)
+                return -ENOMEM;
+        ret = read_blk(info, blk, buf);
+        if (ret < 0) {
+                printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
+                goto out_buf;
+        }
+        ret = 0;
+        blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
+        if (!blk)       /* No reference? */
+                goto out_buf;
+        if (depth < info->dqi_qtree_depth - 1)
+                ret = find_tree_dqentry(info, dquot, blk, depth+1);
+        else
+                ret = find_block_dqentry(info, dquot, blk);
+out_buf:
+        freedqbuf(buf);
+        return ret;
+}
+
+/* Find entry for given id in the tree - wrapper function */
+static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
+                                  struct dquot *dquot)
+{
+        return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
+}
+
+int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
+{
+        int type = dquot->dq_type;
+        struct super_block *sb = dquot->dq_sb;
+        loff_t offset;
+        dqbuf_t ddquot;
+        int ret = 0;
+
+#ifdef __QUOTA_QT_PARANOIA
+        /* Invalidated quota? */
+        if (!sb_dqopt(dquot->dq_sb)->files[type]) {
+                printk(KERN_ERR "VFS: Quota invalidated while reading!\n");
+                return -EIO;
+        }
+#endif
+        /* Do we know offset of the dquot entry in the quota file? */
+        if (!dquot->dq_off) {
+                offset = find_dqentry(info, dquot);
+                if (offset <= 0) {      /* Entry not present? */
+                        if (offset < 0)
+                                printk(KERN_ERR "VFS: Can't read quota "
+                                  "structure for id %u.\n", dquot->dq_id);
+                        dquot->dq_off = 0;
+                        set_bit(DQ_FAKE_B, &dquot->dq_flags);
+                        memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
+                        ret = offset;
+                        goto out;
+                }
+                dquot->dq_off = offset;
+        }
+        ddquot = getdqbuf(info->dqi_entry_size);
+        if (!ddquot)
+                return -ENOMEM;
+        ret = sb->s_op->quota_read(sb, type, (char *)ddquot,
+                                   info->dqi_entry_size, dquot->dq_off);
+        if (ret != info->dqi_entry_size) {
+                if (ret >= 0)
+                        ret = -EIO;
+                printk(KERN_ERR "VFS: Error while reading quota "
+                                "structure for id %u.\n", dquot->dq_id);
+                set_bit(DQ_FAKE_B, &dquot->dq_flags);
+                memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
+                freedqbuf(ddquot);
+                goto out;
+        }
+        spin_lock(&dq_data_lock);
+        info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
+        if (!dquot->dq_dqb.dqb_bhardlimit &&
+            !dquot->dq_dqb.dqb_bsoftlimit &&
+            !dquot->dq_dqb.dqb_ihardlimit &&
+            !dquot->dq_dqb.dqb_isoftlimit)
+                set_bit(DQ_FAKE_B, &dquot->dq_flags);
+        spin_unlock(&dq_data_lock);
+        freedqbuf(ddquot);
+out:
+        dqstats.reads++;
+        return ret;
+}
+EXPORT_SYMBOL(qtree_read_dquot);
+
+/* Check whether dquot should not be deleted. We know we are
+ * the only one operating on dquot (thanks to dq_lock) */
+int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
+{
+        if (test_bit(DQ_FAKE_B, &dquot->dq_flags) && !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
+                return qtree_delete_dquot(info, dquot);
+        return 0;
+}
+EXPORT_SYMBOL(qtree_release_dquot);
diff --git a/fs/quota_tree.h b/fs/quota_tree.h
new file mode 100644
index 000000000000..a1ab8db81a51
--- /dev/null
+++ b/fs/quota_tree.h
@@ -0,0 +1,25 @@
+/*
+ *      Definitions of structures for vfsv0 quota format
+ */
+
+#ifndef _LINUX_QUOTA_TREE_H
+#define _LINUX_QUOTA_TREE_H
+
+#include <linux/types.h>
+#include <linux/quota.h>
+
+/*
+ *  Structure of header of block with quota structures. It is padded to 16 bytes so
+ *  there will be space for exactly 21 quota-entries in a block
+ */
+struct qt_disk_dqdbheader {
+        __le32 dqdh_next_free;  /* Number of next block with free entry */
+        __le32 dqdh_prev_free;  /* Number of previous block with free entry */
+        __le16 dqdh_entries;    /* Number of valid entries in block */
+        __le16 dqdh_pad1;
+        __le32 dqdh_pad2;
+};
+
+#define QT_TREEOFF      1               /* Offset of tree in file in blocks */
+
+#endif /* _LINUX_QUOTAIO_TREE_H */
diff --git a/fs/quota_v2.c b/fs/quota_v2.c
index a21d1a7c356a..a87f1028a425 100644
--- a/fs/quota_v2.c
+++ b/fs/quota_v2.c
@@ -14,6 +14,7 @@
 
 #include <asm/byteorder.h>
 
+#include "quota_tree.h"
 #include "quotaio_v2.h"
 
 MODULE_AUTHOR("Jan Kara");
@@ -22,10 +23,15 @@ MODULE_LICENSE("GPL");
 
 #define __QUOTA_V2_PARANOIA
 
-typedef char *dqbuf_t;
+static void v2_mem2diskdqb(void *dp, struct dquot *dquot);
+static void v2_disk2memdqb(struct dquot *dquot, void *dp);
+static int v2_is_id(void *dp, struct dquot *dquot);
 
-#define GETIDINDEX(id, depth) (((id) >> ((V2_DQTREEDEPTH-(depth)-1)*8)) & 0xff)
-#define GETENTRIES(buf) ((struct v2_disk_dqblk *)(((char *)buf)+sizeof(struct v2_disk_dqdbheader)))
+static struct qtree_fmt_operations v2_qtree_ops = {
+        .mem2disk_dqblk = v2_mem2diskdqb,
+        .disk2mem_dqblk = v2_disk2memdqb,
+        .is_id = v2_is_id,
+};
 
 #define QUOTABLOCK_BITS 10
 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
@@ -64,7 +70,7 @@ static int v2_check_quota_file(struct super_block *sb, int type)
 static int v2_read_file_info(struct super_block *sb, int type)
 {
         struct v2_disk_dqinfo dinfo;
-        struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
+        struct mem_dqinfo *info = sb_dqinfo(sb, type);
         ssize_t size;
 
         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
@@ -80,9 +86,16 @@ static int v2_read_file_info(struct super_block *sb, int type)
         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
         info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
-        info->u.v2_i.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
-        info->u.v2_i.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
-        info->u.v2_i.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
+        info->u.v2_i.i.dqi_sb = sb;
+        info->u.v2_i.i.dqi_type = type;
+        info->u.v2_i.i.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
+        info->u.v2_i.i.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
+        info->u.v2_i.i.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
+        info->u.v2_i.i.dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
+        info->u.v2_i.i.dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
+        info->u.v2_i.i.dqi_qtree_depth = qtree_depth(&info->u.v2_i.i);
+        info->u.v2_i.i.dqi_entry_size = sizeof(struct v2_disk_dqblk);
+        info->u.v2_i.i.dqi_ops = &v2_qtree_ops;
         return 0;
 }
 
@@ -90,7 +103,7 @@ static int v2_read_file_info(struct super_block *sb, int type)
 static int v2_write_file_info(struct super_block *sb, int type)
 {
         struct v2_disk_dqinfo dinfo;
-        struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
+        struct mem_dqinfo *info = sb_dqinfo(sb, type);
         ssize_t size;
 
         spin_lock(&dq_data_lock);
@@ -99,9 +112,9 @@ static int v2_write_file_info(struct super_block *sb, int type)
         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
         dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
         spin_unlock(&dq_data_lock);
-        dinfo.dqi_blocks = cpu_to_le32(info->u.v2_i.dqi_blocks);
-        dinfo.dqi_free_blk = cpu_to_le32(info->u.v2_i.dqi_free_blk);
-        dinfo.dqi_free_entry = cpu_to_le32(info->u.v2_i.dqi_free_entry);
+        dinfo.dqi_blocks = cpu_to_le32(info->u.v2_i.i.dqi_blocks);
+        dinfo.dqi_free_blk = cpu_to_le32(info->u.v2_i.i.dqi_free_blk);
+        dinfo.dqi_free_entry = cpu_to_le32(info->u.v2_i.i.dqi_free_entry);
         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
         if (size != sizeof(struct v2_disk_dqinfo)) {
@@ -112,8 +125,11 @@ static int v2_write_file_info(struct super_block *sb, int type)
         return 0;
 }
 
-static void disk2memdqb(struct mem_dqblk *m, struct v2_disk_dqblk *d)
+static void v2_disk2memdqb(struct dquot *dquot, void *dp)
 {
+        struct v2_disk_dqblk *d = dp, empty;
+        struct mem_dqblk *m = &dquot->dq_dqb;
+
         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
@@ -122,10 +138,20 @@ static void disk2memdqb(struct mem_dqblk *m, struct v2_disk_dqblk *d)
         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
         m->dqb_btime = le64_to_cpu(d->dqb_btime);
+        /* We need to escape back all-zero structure */
+        memset(&empty, 0, sizeof(struct v2_disk_dqblk));
+        empty.dqb_itime = cpu_to_le64(1);
+        if (!memcmp(&empty, dp, sizeof(struct v2_disk_dqblk)))
+                m->dqb_itime = 0;
 }
 
-static void mem2diskdqb(struct v2_disk_dqblk *d, struct mem_dqblk *m, qid_t id)
+static void v2_mem2diskdqb(void *dp, struct dquot *dquot)
 {
+        struct v2_disk_dqblk *d = dp;
+        struct mem_dqblk *m = &dquot->dq_dqb;
+        struct qtree_mem_dqinfo *info =
+                        &sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i;
+
         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
@@ -134,553 +160,35 @@ static void mem2diskdqb(struct v2_disk_dqblk *d, struct mem_dqblk *m, qid_t id)
         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
         d->dqb_btime = cpu_to_le64(m->dqb_btime);
-        d->dqb_id = cpu_to_le32(id);
-}
-
-static dqbuf_t getdqbuf(void)
-{
-        dqbuf_t buf = kmalloc(V2_DQBLKSIZE, GFP_NOFS);
-        if (!buf)
-                printk(KERN_WARNING "VFS: Not enough memory for quota buffers.\n");
-        return buf;
-}
-
-static inline void freedqbuf(dqbuf_t buf)
-{
-        kfree(buf);
-}
-
-static inline ssize_t read_blk(struct super_block *sb, int type, uint blk, dqbuf_t buf)
-{
-        memset(buf, 0, V2_DQBLKSIZE);
-        return sb->s_op->quota_read(sb, type, (char *)buf,
-               V2_DQBLKSIZE, blk << V2_DQBLKSIZE_BITS);
-}
-
-static inline ssize_t write_blk(struct super_block *sb, int type, uint blk, dqbuf_t buf)
-{
-        return sb->s_op->quota_write(sb, type, (char *)buf,
-               V2_DQBLKSIZE, blk << V2_DQBLKSIZE_BITS);
-}
-
-/* Remove empty block from list and return it */
-static int get_free_dqblk(struct super_block *sb, int type)
-{
-        dqbuf_t buf = getdqbuf();
-        struct mem_dqinfo *info = sb_dqinfo(sb, type);
-        struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
-        int ret, blk;
-
-        if (!buf)
-                return -ENOMEM;
-        if (info->u.v2_i.dqi_free_blk) {
-                blk = info->u.v2_i.dqi_free_blk;
-                if ((ret = read_blk(sb, type, blk, buf)) < 0)
-                        goto out_buf;
-                info->u.v2_i.dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
-        }
-        else {
-                memset(buf, 0, V2_DQBLKSIZE);
-                /* Assure block allocation... */
-                if ((ret = write_blk(sb, type, info->u.v2_i.dqi_blocks, buf)) < 0)
-                        goto out_buf;
-                blk = info->u.v2_i.dqi_blocks++;
-        }
-        mark_info_dirty(sb, type);
-        ret = blk;
-out_buf:
-        freedqbuf(buf);
-        return ret;
-}
-
-/* Insert empty block to the list */
-static int put_free_dqblk(struct super_block *sb, int type, dqbuf_t buf, uint blk)
-{
-        struct mem_dqinfo *info = sb_dqinfo(sb, type);
-        struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
-        int err;
-
-        dh->dqdh_next_free = cpu_to_le32(info->u.v2_i.dqi_free_blk);
-        dh->dqdh_prev_free = cpu_to_le32(0);
-        dh->dqdh_entries = cpu_to_le16(0);
-        info->u.v2_i.dqi_free_blk = blk;
-        mark_info_dirty(sb, type);
-        /* Some strange block. We had better leave it... */
-        if ((err = write_blk(sb, type, blk, buf)) < 0)
-                return err;
-        return 0;
+        d->dqb_id = cpu_to_le32(dquot->dq_id);
+        if (qtree_entry_unused(info, dp))
+                d->dqb_itime = cpu_to_le64(1);
 }
 
-/* Remove given block from the list of blocks with free entries */
-static int remove_free_dqentry(struct super_block *sb, int type, dqbuf_t buf, uint blk)
+static int v2_is_id(void *dp, struct dquot *dquot)
 {
-        dqbuf_t tmpbuf = getdqbuf();
-        struct mem_dqinfo *info = sb_dqinfo(sb, type);
-        struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
-        uint nextblk = le32_to_cpu(dh->dqdh_next_free), prevblk = le32_to_cpu(dh->dqdh_prev_free);
-        int err;
+        struct v2_disk_dqblk *d = dp;
+        struct qtree_mem_dqinfo *info =
+                        &sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i;
 
-        if (!tmpbuf)
-                return -ENOMEM;
-        if (nextblk) {
-                if ((err = read_blk(sb, type, nextblk, tmpbuf)) < 0)
-                        goto out_buf;
-                ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = dh->dqdh_prev_free;
-                if ((err = write_blk(sb, type, nextblk, tmpbuf)) < 0)
-                        goto out_buf;
-        }
-        if (prevblk) {
-                if ((err = read_blk(sb, type, prevblk, tmpbuf)) < 0)
-                        goto out_buf;
-                ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_next_free = dh->dqdh_next_free;
-                if ((err = write_blk(sb, type, prevblk, tmpbuf)) < 0)
-                        goto out_buf;
-        }
-        else {
-                info->u.v2_i.dqi_free_entry = nextblk;
-                mark_info_dirty(sb, type);
-        }
-        freedqbuf(tmpbuf);
-        dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
-        /* No matter whether write succeeds block is out of list */
-        if (write_blk(sb, type, blk, buf) < 0)
-                printk(KERN_ERR "VFS: Can't write block (%u) with free entries.\n", blk);
-        return 0;
-out_buf:
-        freedqbuf(tmpbuf);
-        return err;
-}
-
-/* Insert given block to the beginning of list with free entries */
-static int insert_free_dqentry(struct super_block *sb, int type, dqbuf_t buf, uint blk)
-{
-        dqbuf_t tmpbuf = getdqbuf();
-        struct mem_dqinfo *info = sb_dqinfo(sb, type);
-        struct v2_disk_dqdbheader *dh = (struct v2_disk_dqdbheader *)buf;
-        int err;
-
-        if (!tmpbuf)
-                return -ENOMEM;
-        dh->dqdh_next_free = cpu_to_le32(info->u.v2_i.dqi_free_entry);
-        dh->dqdh_prev_free = cpu_to_le32(0);
-        if ((err = write_blk(sb, type, blk, buf)) < 0)
-                goto out_buf;
-        if (info->u.v2_i.dqi_free_entry) {
-                if ((err = read_blk(sb, type, info->u.v2_i.dqi_free_entry, tmpbuf)) < 0)
-                        goto out_buf;
-                ((struct v2_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = cpu_to_le32(blk);
-                if ((err = write_blk(sb, type, info->u.v2_i.dqi_free_entry, tmpbuf)) < 0)
-                        goto out_buf;
-        }
-        freedqbuf(tmpbuf);
-        info->u.v2_i.dqi_free_entry = blk;
-        mark_info_dirty(sb, type);
-        return 0;
-out_buf:
-        freedqbuf(tmpbuf);
-        return err;
-}
-
-/* Find space for dquot */
-static uint find_free_dqentry(struct dquot *dquot, int *err)
-{
-        struct super_block *sb = dquot->dq_sb;
-        struct mem_dqinfo *info = sb_dqopt(sb)->info+dquot->dq_type;
-        uint blk, i;
-        struct v2_disk_dqdbheader *dh;
-        struct v2_disk_dqblk *ddquot;
-        struct v2_disk_dqblk fakedquot;
-        dqbuf_t buf;
-
-        *err = 0;
-        if (!(buf = getdqbuf())) {
-                *err = -ENOMEM;
+        if (qtree_entry_unused(info, dp))
                 return 0;
-        }
-        dh = (struct v2_disk_dqdbheader *)buf;
-        ddquot = GETENTRIES(buf);
-        if (info->u.v2_i.dqi_free_entry) {
-                blk = info->u.v2_i.dqi_free_entry;
-                if ((*err = read_blk(sb, dquot->dq_type, blk, buf)) < 0)
-                        goto out_buf;
-        }
-        else {
-                blk = get_free_dqblk(sb, dquot->dq_type);
-                if ((int)blk < 0) {
-                        *err = blk;
-                        freedqbuf(buf);
-                        return 0;
-                }
-                memset(buf, 0, V2_DQBLKSIZE);
-                /* This is enough as block is already zeroed and entry list is empty... */
-                info->u.v2_i.dqi_free_entry = blk;
-                mark_info_dirty(sb, dquot->dq_type);
-        }
-        if (le16_to_cpu(dh->dqdh_entries)+1 >= V2_DQSTRINBLK)   /* Block will be full? */
-                if ((*err = remove_free_dqentry(sb, dquot->dq_type, buf, blk)) < 0) {
-                        printk(KERN_ERR "VFS: find_free_dqentry(): Can't remove block (%u) from entry free list.\n", blk);
-                        goto out_buf;
-                }
-        le16_add_cpu(&dh->dqdh_entries, 1);
-        memset(&fakedquot, 0, sizeof(struct v2_disk_dqblk));
-        /* Find free structure in block */
-        for (i = 0; i < V2_DQSTRINBLK && memcmp(&fakedquot, ddquot+i, sizeof(struct v2_disk_dqblk)); i++);
-#ifdef __QUOTA_V2_PARANOIA
-        if (i == V2_DQSTRINBLK) {
-                printk(KERN_ERR "VFS: find_free_dqentry(): Data block full but it shouldn't.\n");
-                *err = -EIO;
-                goto out_buf;
-        }
-#endif
-        if ((*err = write_blk(sb, dquot->dq_type, blk, buf)) < 0) {
-                printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota data block %u.\n", blk);
-                goto out_buf;
-        }
-        dquot->dq_off = (blk<<V2_DQBLKSIZE_BITS)+sizeof(struct v2_disk_dqdbheader)+i*sizeof(struct v2_disk_dqblk);
-        freedqbuf(buf);
-        return blk;
-out_buf:
-        freedqbuf(buf);
-        return 0;
+        return le32_to_cpu(d->dqb_id) == dquot->dq_id;
 }
 
-/* Insert reference to structure into the trie */
-static int do_insert_tree(struct dquot *dquot, uint *treeblk, int depth)
-{
-        struct super_block *sb = dquot->dq_sb;
-        dqbuf_t buf;
-        int ret = 0, newson = 0, newact = 0;
-        __le32 *ref;
-        uint newblk;
-
-        if (!(buf = getdqbuf()))
-                return -ENOMEM;
-        if (!*treeblk) {
-                ret = get_free_dqblk(sb, dquot->dq_type);
-                if (ret < 0)
-                        goto out_buf;
-                *treeblk = ret;
-                memset(buf, 0, V2_DQBLKSIZE);
-                newact = 1;
-        }
-        else {
-                if ((ret = read_blk(sb, dquot->dq_type, *treeblk, buf)) < 0) {
-                        printk(KERN_ERR "VFS: Can't read tree quota block %u.\n", *treeblk);
-                        goto out_buf;
-                }
-        }
-        ref = (__le32 *)buf;
-        newblk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]);
-        if (!newblk)
-                newson = 1;
-        if (depth == V2_DQTREEDEPTH-1) {
-#ifdef __QUOTA_V2_PARANOIA
-                if (newblk) {
-                        printk(KERN_ERR "VFS: Inserting already present quota entry (block %u).\n", le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]));
-                        ret = -EIO;
-                        goto out_buf;
-                }
-#endif
-                newblk = find_free_dqentry(dquot, &ret);
-        }
-        else
-                ret = do_insert_tree(dquot, &newblk, depth+1);
-        if (newson && ret >= 0) {
-                ref[GETIDINDEX(dquot->dq_id, depth)] = cpu_to_le32(newblk);
-                ret = write_blk(sb, dquot->dq_type, *treeblk, buf);
-        }
-        else if (newact && ret < 0)
-                put_free_dqblk(sb, dquot->dq_type, buf, *treeblk);
-out_buf:
-        freedqbuf(buf);
-        return ret;
-}
-
-/* Wrapper for inserting quota structure into tree */
-static inline int dq_insert_tree(struct dquot *dquot)
+static int v2_read_dquot(struct dquot *dquot)
 {
-        int tmp = V2_DQTREEOFF;
-        return do_insert_tree(dquot, &tmp, 0);
+        return qtree_read_dquot(&sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i, dquot);
 }
 
-/*
- *      We don't have to be afraid of deadlocks as we never have quotas on quota files...
- */
 static int v2_write_dquot(struct dquot *dquot)
 {
-        int type = dquot->dq_type;
-        ssize_t ret;
-        struct v2_disk_dqblk ddquot, empty;
-
-        /* dq_off is guarded by dqio_mutex */
-        if (!dquot->dq_off)
-                if ((ret = dq_insert_tree(dquot)) < 0) {
-                        printk(KERN_ERR "VFS: Error %zd occurred while creating quota.\n", ret);
-                        return ret;
-                }
-        spin_lock(&dq_data_lock);
-        mem2diskdqb(&ddquot, &dquot->dq_dqb, dquot->dq_id);
-        /* Argh... We may need to write structure full of zeroes but that would be
-         * treated as an empty place by the rest of the code. Format change would
-         * be definitely cleaner but the problems probably are not worth it */
-        memset(&empty, 0, sizeof(struct v2_disk_dqblk));
-        if (!memcmp(&empty, &ddquot, sizeof(struct v2_disk_dqblk)))
-                ddquot.dqb_itime = cpu_to_le64(1);
-        spin_unlock(&dq_data_lock);
-        ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
-              (char *)&ddquot, sizeof(struct v2_disk_dqblk), dquot->dq_off);
-        if (ret != sizeof(struct v2_disk_dqblk)) {
-                printk(KERN_WARNING "VFS: dquota write failed on dev %s\n", dquot->dq_sb->s_id);
-                if (ret >= 0)
-                        ret = -ENOSPC;
-        }
-        else
-                ret = 0;
-        dqstats.writes++;
-
-        return ret;
+        return qtree_write_dquot(&sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i, dquot);
 }
 
-/* Free dquot entry in data block */
-static int free_dqentry(struct dquot *dquot, uint blk)
-{
-        struct super_block *sb = dquot->dq_sb;
-        int type = dquot->dq_type;
-        struct v2_disk_dqdbheader *dh;
-        dqbuf_t buf = getdqbuf();
-        int ret = 0;
-
-        if (!buf)
-                return -ENOMEM;
-        if (dquot->dq_off >> V2_DQBLKSIZE_BITS != blk) {
-                printk(KERN_ERR "VFS: Quota structure has offset to other "
-                  "block (%u) than it should (%u).\n", blk,
-                  (uint)(dquot->dq_off >> V2_DQBLKSIZE_BITS));
-                goto out_buf;
-        }
-        if ((ret = read_blk(sb, type, blk, buf)) < 0) {
-                printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
-                goto out_buf;
-        }
-        dh = (struct v2_disk_dqdbheader *)buf;
-        le16_add_cpu(&dh->dqdh_entries, -1);
-        if (!le16_to_cpu(dh->dqdh_entries)) {   /* Block got free? */
-                if ((ret = remove_free_dqentry(sb, type, buf, blk)) < 0 ||
-                    (ret = put_free_dqblk(sb, type, buf, blk)) < 0) {
-                        printk(KERN_ERR "VFS: Can't move quota data block (%u) "
-                          "to free list.\n", blk);
-                        goto out_buf;
-                }
-        }
-        else {
-                memset(buf+(dquot->dq_off & ((1 << V2_DQBLKSIZE_BITS)-1)), 0,
-                  sizeof(struct v2_disk_dqblk));
-                if (le16_to_cpu(dh->dqdh_entries) == V2_DQSTRINBLK-1) {
-                        /* Insert will write block itself */
-                        if ((ret = insert_free_dqentry(sb, type, buf, blk)) < 0) {
-                                printk(KERN_ERR "VFS: Can't insert quota data block (%u) to free entry list.\n", blk);
-                                goto out_buf;
-                        }
-                }
-                else
-                        if ((ret = write_blk(sb, type, blk, buf)) < 0) {
-                                printk(KERN_ERR "VFS: Can't write quota data "
-                                  "block %u\n", blk);
-                                goto out_buf;
-                        }
-        }
-        dquot->dq_off = 0;      /* Quota is now unattached */
-out_buf:
-        freedqbuf(buf);
-        return ret;
-}
-
-/* Remove reference to dquot from tree */
-static int remove_tree(struct dquot *dquot, uint *blk, int depth)
-{
-        struct super_block *sb = dquot->dq_sb;
-        int type = dquot->dq_type;
-        dqbuf_t buf = getdqbuf();
-        int ret = 0;
-        uint newblk;
-        __le32 *ref = (__le32 *)buf;
-        
-        if (!buf)
-                return -ENOMEM;
-        if ((ret = read_blk(sb, type, *blk, buf)) < 0) {
-                printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
-                goto out_buf;
-        }
-        newblk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]);
-        if (depth == V2_DQTREEDEPTH-1) {
-                ret = free_dqentry(dquot, newblk);
-                newblk = 0;
-        }
-        else
-                ret = remove_tree(dquot, &newblk, depth+1);
-        if (ret >= 0 && !newblk) {
-                int i;
-                ref[GETIDINDEX(dquot->dq_id, depth)] = cpu_to_le32(0);
-                for (i = 0; i < V2_DQBLKSIZE && !buf[i]; i++);  /* Block got empty? */
-                /* Don't put the root block into the free block list */
-                if (i == V2_DQBLKSIZE && *blk != V2_DQTREEOFF) {
-                        put_free_dqblk(sb, type, buf, *blk);
-                        *blk = 0;
-                }
-                else
-                        if ((ret = write_blk(sb, type, *blk, buf)) < 0)
-                                printk(KERN_ERR "VFS: Can't write quota tree "
-                                  "block %u.\n", *blk);
-        }
-out_buf:
-        freedqbuf(buf);
-        return ret;     
-}
-
-/* Delete dquot from tree */
-static int v2_delete_dquot(struct dquot *dquot)
-{
-        uint tmp = V2_DQTREEOFF;
-
-        if (!dquot->dq_off)     /* Even not allocated? */
-                return 0;
-        return remove_tree(dquot, &tmp, 0);
-}
-
-/* Find entry in block */
-static loff_t find_block_dqentry(struct dquot *dquot, uint blk)
-{
-        dqbuf_t buf = getdqbuf();
-        loff_t ret = 0;
-        int i;
-        struct v2_disk_dqblk *ddquot = GETENTRIES(buf);
-
-        if (!buf)
-                return -ENOMEM;
-        if ((ret = read_blk(dquot->dq_sb, dquot->dq_type, blk, buf)) < 0) {
-                printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
-                goto out_buf;
-        }
-        if (dquot->dq_id)
-                for (i = 0; i < V2_DQSTRINBLK &&
-                     le32_to_cpu(ddquot[i].dqb_id) != dquot->dq_id; i++);
-        else {  /* ID 0 as a bit more complicated searching... */
-                struct v2_disk_dqblk fakedquot;
-
-                memset(&fakedquot, 0, sizeof(struct v2_disk_dqblk));
-                for (i = 0; i < V2_DQSTRINBLK; i++)
-                        if (!le32_to_cpu(ddquot[i].dqb_id) &&
-                            memcmp(&fakedquot, ddquot+i, sizeof(struct v2_disk_dqblk)))
-                                break;
-        }
-        if (i == V2_DQSTRINBLK) {
-                printk(KERN_ERR "VFS: Quota for id %u referenced "
-                  "but not present.\n", dquot->dq_id);
-                ret = -EIO;
-                goto out_buf;
-        }
-        else
-                ret = (blk << V2_DQBLKSIZE_BITS) + sizeof(struct
-                  v2_disk_dqdbheader) + i * sizeof(struct v2_disk_dqblk);
-out_buf:
-        freedqbuf(buf);
-        return ret;
-}
-
-/* Find entry for given id in the tree */
-static loff_t find_tree_dqentry(struct dquot *dquot, uint blk, int depth)
-{
-        dqbuf_t buf = getdqbuf();
-        loff_t ret = 0;
-        __le32 *ref = (__le32 *)buf;
-
-        if (!buf)
-                return -ENOMEM;
-        if ((ret = read_blk(dquot->dq_sb, dquot->dq_type, blk, buf)) < 0) {
-                printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
-                goto out_buf;
-        }
-        ret = 0;
-        blk = le32_to_cpu(ref[GETIDINDEX(dquot->dq_id, depth)]);
-        if (!blk)       /* No reference? */
-                goto out_buf;
-        if (depth < V2_DQTREEDEPTH-1)
-                ret = find_tree_dqentry(dquot, blk, depth+1);
-        else
-                ret = find_block_dqentry(dquot, blk);
-out_buf:
-        freedqbuf(buf);
-        return ret;
-}
-
-/* Find entry for given id in the tree - wrapper function */
-static inline loff_t find_dqentry(struct dquot *dquot)
-{
-        return find_tree_dqentry(dquot, V2_DQTREEOFF, 0);
-}
-
-static int v2_read_dquot(struct dquot *dquot)
-{
-        int type = dquot->dq_type;
-        loff_t offset;
-        struct v2_disk_dqblk ddquot, empty;
-        int ret = 0;
-
-#ifdef __QUOTA_V2_PARANOIA
-        /* Invalidated quota? */
-        if (!dquot->dq_sb || !sb_dqopt(dquot->dq_sb)->files[type]) {
-                printk(KERN_ERR "VFS: Quota invalidated while reading!\n");
-                return -EIO;
-        }
-#endif
-        offset = find_dqentry(dquot);
-        if (offset <= 0) {      /* Entry not present? */
-                if (offset < 0)
-                        printk(KERN_ERR "VFS: Can't read quota "
-                          "structure for id %u.\n", dquot->dq_id);
-                dquot->dq_off = 0;
-                set_bit(DQ_FAKE_B, &dquot->dq_flags);
-                memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
-                ret = offset;
-        }
-        else {
-                dquot->dq_off = offset;
-                if ((ret = dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type,
-                    (char *)&ddquot, sizeof(struct v2_disk_dqblk), offset))
-                    != sizeof(struct v2_disk_dqblk)) {
-                        if (ret >= 0)
-                                ret = -EIO;
-                        printk(KERN_ERR "VFS: Error while reading quota "
-                          "structure for id %u.\n", dquot->dq_id);
-                        memset(&ddquot, 0, sizeof(struct v2_disk_dqblk));
-                }
-                else {
-                        ret = 0;
-                        /* We need to escape back all-zero structure */
-                        memset(&empty, 0, sizeof(struct v2_disk_dqblk));
-                        empty.dqb_itime = cpu_to_le64(1);
-                        if (!memcmp(&empty, &ddquot, sizeof(struct v2_disk_dqblk)))
-                                ddquot.dqb_itime = 0;
-                }
-                disk2memdqb(&dquot->dq_dqb, &ddquot);
-                if (!dquot->dq_dqb.dqb_bhardlimit &&
-                        !dquot->dq_dqb.dqb_bsoftlimit &&
-                        !dquot->dq_dqb.dqb_ihardlimit &&
-                        !dquot->dq_dqb.dqb_isoftlimit)
-                        set_bit(DQ_FAKE_B, &dquot->dq_flags);
-        }
-        dqstats.reads++;
-
-        return ret;
-}
-
-/* Check whether dquot should not be deleted. We know we are
- * the only one operating on dquot (thanks to dq_lock) */
 static int v2_release_dquot(struct dquot *dquot)
 {
-        if (test_bit(DQ_FAKE_B, &dquot->dq_flags) && !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
-                return v2_delete_dquot(dquot);
-        return 0;
+        return qtree_release_dquot(&sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i, dquot);
 }
 
 static struct quota_format_ops v2_format_ops = {
diff --git a/fs/quotaio_v2.h b/fs/quotaio_v2.h
index 303d7cbe30d4..530fe580685c 100644
--- a/fs/quotaio_v2.h
+++ b/fs/quotaio_v2.h
@@ -21,6 +21,12 @@
         0               /* GRPQUOTA */\
 }
 
+/* First generic header */
+struct v2_disk_dqheader {
+        __le32 dqh_magic;       /* Magic number identifying file */
+        __le32 dqh_version;     /* File version */
+};
+
 /*
  * The following structure defines the format of the disk quota file
  * (as it appears on disk) - the file is a radix tree whose leaves point
@@ -38,15 +44,6 @@ struct v2_disk_dqblk {
         __le64 dqb_itime;       /* time limit for excessive inode use */
 };
 
-/*
- * Here are header structures as written on disk and their in-memory copies
- */
-/* First generic header */
-struct v2_disk_dqheader {
-        __le32 dqh_magic;       /* Magic number identifying file */
-        __le32 dqh_version;     /* File version */
-};
-
 /* Header with type and version specific information */
 struct v2_disk_dqinfo {
         __le32 dqi_bgrace;      /* Time before block soft limit becomes hard limit */
@@ -57,23 +54,7 @@ struct v2_disk_dqinfo {
         __le32 dqi_free_entry;  /* Number of block with at least one free entry */
 };
 
-/*
- *  Structure of header of block with quota structures. It is padded to 16 bytes so
- *  there will be space for exactly 21 quota-entries in a block
- */
-struct v2_disk_dqdbheader {
-        __le32 dqdh_next_free;  /* Number of next block with free entry */
-        __le32 dqdh_prev_free;  /* Number of previous block with free entry */
-        __le16 dqdh_entries;    /* Number of valid entries in block */
-        __le16 dqdh_pad1;
-        __le32 dqdh_pad2;
-};
-
 #define V2_DQINFOOFF    sizeof(struct v2_disk_dqheader) /* Offset of info header in file */
-#define V2_DQBLKSIZE_BITS       10
-#define V2_DQBLKSIZE    (1 << V2_DQBLKSIZE_BITS)        /* Size of block with quota structures */
-#define V2_DQTREEOFF    1               /* Offset of tree in file in blocks */
-#define V2_DQTREEDEPTH  4               /* Depth of quota tree */
-#define V2_DQSTRINBLK   ((V2_DQBLKSIZE - sizeof(struct v2_disk_dqdbheader)) / sizeof(struct v2_disk_dqblk))     /* Number of entries in one blocks */
+#define V2_DQBLKSIZE_BITS 10                            /* Size of leaf block in tree */
 
 #endif /* _LINUX_QUOTAIO_V2_H */