ocfs2: Fix quota locking
authorJan Kara <jack@suse.cz>
Wed, 31 Mar 2010 14:25:37 +0000 (16:25 +0200)
committerJan Kara <jack@suse.cz>
Fri, 21 May 2010 17:30:47 +0000 (19:30 +0200)
OCFS2 had three issues with quota locking:
a) When reading dquot from global quota file, we started a transaction while
   holding dqio_mutex which is prone to deadlocks because other paths do it
   the other way around
b) During ocfs2_sync_dquot we were not protected against concurrent writers
   on the same node. Because we first copy data to local buffer, a race
   could happen resulting in old data being written to global quota file and
   thus causing quota inconsistency after a crash.
c) ip_alloc_sem of quota files was acquired while a transaction is started
   in ocfs2_quota_write which can deadlock because we first get ip_alloc_sem
   and then start a transaction when extending quota files.

We fix the problem a) by pulling all necessary code to ocfs2_acquire_dquot
and ocfs2_release_dquot. Thus we no longer depend on generic dquot_acquire
to do the locking and can force proper lock ordering.

Problems b) and c) are fixed by locking i_mutex and ip_alloc_sem of
global quota file in ocfs2_lock_global_qf and removing ip_alloc_sem from
ocfs2_quota_read and ocfs2_quota_write.

Acked-by: Joel Becker <Joel.Becker@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
fs/ocfs2/quota.h
fs/ocfs2/quota_global.c
fs/ocfs2/quota_local.c

index c762343..903ffa9 100644 (file)
@@ -104,10 +104,11 @@ static inline int ocfs2_global_release_dquot(struct dquot *dquot)
 
 int ocfs2_lock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex);
 void ocfs2_unlock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex);
-int ocfs2_read_quota_block(struct inode *inode, u64 v_block,
-                          struct buffer_head **bh);
+int ocfs2_validate_quota_block(struct super_block *sb, struct buffer_head *bh);
 int ocfs2_read_quota_phys_block(struct inode *inode, u64 p_block,
                                struct buffer_head **bh);
+int ocfs2_create_local_dquot(struct dquot *dquot);
+int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
 
 extern const struct dquot_operations ocfs2_quota_operations;
 extern struct quota_format_type ocfs2_quota_format;
index f391b11..1e3e0d5 100644 (file)
 #include "buffer_head_io.h"
 #include "quota.h"
 
+/*
+ * Locking of quotas with OCFS2 is rather complex. Here are rules that
+ * should be obeyed by all the functions:
+ * - any write of quota structure (either to local or global file) is protected
+ *   by dqio_mutex or dquot->dq_lock.
+ * - any modification of global quota file holds inode cluster lock, i_mutex,
+ *   and ip_alloc_sem of the global quota file (achieved by
+ *   ocfs2_lock_global_qf). It also has to hold qinfo_lock.
+ * - an allocation of new blocks for local quota file is protected by
+ *   its ip_alloc_sem
+ *
+ * A rough sketch of locking dependencies (lf = local file, gf = global file):
+ * Normal filesystem operation:
+ *   start_trans -> dqio_mutex -> write to lf
+ * Syncing of local and global file:
+ *   ocfs2_lock_global_qf -> start_trans -> dqio_mutex -> qinfo_lock ->
+ *     write to gf
+ *                                                    -> write to lf
+ * Acquire dquot for the first time:
+ *   dq_lock -> ocfs2_lock_global_qf -> qinfo_lock -> read from gf
+ *                                  -> alloc space for gf
+ *                                  -> start_trans -> qinfo_lock -> write to gf
+ *          -> ip_alloc_sem of lf -> alloc space for lf
+ *          -> write to lf
+ * Release last reference to dquot:
+ *   dq_lock -> ocfs2_lock_global_qf -> start_trans -> qinfo_lock -> write to gf
+ *          -> write to lf
+ * Note that all the above operations also hold the inode cluster lock of lf.
+ * Recovery:
+ *   inode cluster lock of recovered lf
+ *     -> read bitmaps -> ip_alloc_sem of lf
+ *     -> ocfs2_lock_global_qf -> start_trans -> dqio_mutex -> qinfo_lock ->
+ *        write to gf
+ */
+
 static struct workqueue_struct *ocfs2_quota_wq = NULL;
 
 static void qsync_work_fn(struct work_struct *work);
@@ -92,8 +127,7 @@ struct qtree_fmt_operations ocfs2_global_ops = {
        .is_id = ocfs2_global_is_id,
 };
 
-static int ocfs2_validate_quota_block(struct super_block *sb,
-                                     struct buffer_head *bh)
+int ocfs2_validate_quota_block(struct super_block *sb, struct buffer_head *bh)
 {
        struct ocfs2_disk_dqtrailer *dqt =
                ocfs2_block_dqtrailer(sb->s_blocksize, bh->b_data);
@@ -111,33 +145,6 @@ static int ocfs2_validate_quota_block(struct super_block *sb,
        return ocfs2_validate_meta_ecc(sb, bh->b_data, &dqt->dq_check);
 }
 
-int ocfs2_read_quota_block(struct inode *inode, u64 v_block,
-                          struct buffer_head **bh)
-{
-       int rc = 0;
-       struct buffer_head *tmp = *bh;
-
-       if (i_size_read(inode) >> inode->i_sb->s_blocksize_bits <= v_block) {
-               ocfs2_error(inode->i_sb,
-                           "Quota file %llu is probably corrupted! Requested "
-                           "to read block %Lu but file has size only %Lu\n",
-                           (unsigned long long)OCFS2_I(inode)->ip_blkno,
-                           (unsigned long long)v_block,
-                           (unsigned long long)i_size_read(inode));
-               return -EIO;
-       }
-       rc = ocfs2_read_virt_blocks(inode, v_block, 1, &tmp, 0,
-                                   ocfs2_validate_quota_block);
-       if (rc)
-               mlog_errno(rc);
-
-       /* If ocfs2_read_virt_blocks() got us a new bh, pass it up. */
-       if (!rc && !*bh)
-               *bh = tmp;
-
-       return rc;
-}
-
 int ocfs2_read_quota_phys_block(struct inode *inode, u64 p_block,
                                struct buffer_head **bhp)
 {
@@ -151,27 +158,6 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64 p_block,
        return rc;
 }
 
-static int ocfs2_get_quota_block(struct inode *inode, int block,
-                                struct buffer_head **bh)
-{
-       u64 pblock, pcount;
-       int err;
-
-       down_read(&OCFS2_I(inode)->ip_alloc_sem);
-       err = ocfs2_extent_map_get_blocks(inode, block, &pblock, &pcount, NULL);
-       up_read(&OCFS2_I(inode)->ip_alloc_sem);
-       if (err) {
-               mlog_errno(err);
-               return err;
-       }
-       *bh = sb_getblk(inode->i_sb, pblock);
-       if (!*bh) {
-               err = -EIO;
-               mlog_errno(err);
-       }
-       return err;
-}
-
 /* Read data from global quotafile - avoid pagecache and such because we cannot
  * afford acquiring the locks... We use quota cluster lock to serialize
  * operations. Caller is responsible for acquiring it. */
@@ -186,6 +172,7 @@ ssize_t ocfs2_quota_read(struct super_block *sb, int type, char *data,
        int err = 0;
        struct buffer_head *bh;
        size_t toread, tocopy;
+       u64 pblock = 0, pcount = 0;
 
        if (off > i_size)
                return 0;
@@ -194,8 +181,19 @@ ssize_t ocfs2_quota_read(struct super_block *sb, int type, char *data,
        toread = len;
        while (toread > 0) {
                tocopy = min_t(size_t, (sb->s_blocksize - offset), toread);
+               if (!pcount) {
+                       err = ocfs2_extent_map_get_blocks(gqinode, blk, &pblock,
+                                                         &pcount, NULL);
+                       if (err) {
+                               mlog_errno(err);
+                               return err;
+                       }
+               } else {
+                       pcount--;
+                       pblock++;
+               }
                bh = NULL;
-               err = ocfs2_read_quota_block(gqinode, blk, &bh);
+               err = ocfs2_read_quota_phys_block(gqinode, pblock, &bh);
                if (err) {
                        mlog_errno(err);
                        return err;
@@ -223,6 +221,7 @@ ssize_t ocfs2_quota_write(struct super_block *sb, int type,
        int err = 0, new = 0, ja_type;
        struct buffer_head *bh = NULL;
        handle_t *handle = journal_current_handle();
+       u64 pblock, pcount;
 
        if (!handle) {
                mlog(ML_ERROR, "Quota write (off=%llu, len=%llu) cancelled "
@@ -235,12 +234,11 @@ ssize_t ocfs2_quota_write(struct super_block *sb, int type,
                len = sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE - offset;
        }
 
-       mutex_lock_nested(&gqinode->i_mutex, I_MUTEX_QUOTA);
        if (gqinode->i_size < off + len) {
                loff_t rounded_end =
                                ocfs2_align_bytes_to_blocks(sb, off + len);
 
-               /* Space is already allocated in ocfs2_global_read_dquot() */
+               /* Space is already allocated in ocfs2_acquire_dquot() */
                err = ocfs2_simple_size_update(gqinode,
                                               oinfo->dqi_gqi_bh,
                                               rounded_end);
@@ -248,13 +246,20 @@ ssize_t ocfs2_quota_write(struct super_block *sb, int type,
                        goto out;
                new = 1;
        }
+       err = ocfs2_extent_map_get_blocks(gqinode, blk, &pblock, &pcount, NULL);
+       if (err) {
+               mlog_errno(err);
+               goto out;
+       }
        /* Not rewriting whole block? */
        if ((offset || len < sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE) &&
            !new) {
-               err = ocfs2_read_quota_block(gqinode, blk, &bh);
+               err = ocfs2_read_quota_phys_block(gqinode, pblock, &bh);
                ja_type = OCFS2_JOURNAL_ACCESS_WRITE;
        } else {
-               err = ocfs2_get_quota_block(gqinode, blk, &bh);
+               bh = sb_getblk(sb, pblock);
+               if (!bh)
+                       err = -ENOMEM;
                ja_type = OCFS2_JOURNAL_ACCESS_CREATE;
        }
        if (err) {
@@ -279,13 +284,11 @@ ssize_t ocfs2_quota_write(struct super_block *sb, int type,
        brelse(bh);
 out:
        if (err) {
-               mutex_unlock(&gqinode->i_mutex);
                mlog_errno(err);
                return err;
        }
        gqinode->i_version++;
        ocfs2_mark_inode_dirty(handle, gqinode, oinfo->dqi_gqi_bh);
-       mutex_unlock(&gqinode->i_mutex);
        return len;
 }
 
@@ -303,11 +306,23 @@ int ocfs2_lock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex)
        else
                WARN_ON(bh != oinfo->dqi_gqi_bh);
        spin_unlock(&dq_data_lock);
+       if (ex) {
+               mutex_lock(&oinfo->dqi_gqinode->i_mutex);
+               down_write(&OCFS2_I(oinfo->dqi_gqinode)->ip_alloc_sem);
+       } else {
+               down_read(&OCFS2_I(oinfo->dqi_gqinode)->ip_alloc_sem);
+       }
        return 0;
 }
 
 void ocfs2_unlock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex)
 {
+       if (ex) {
+               up_write(&OCFS2_I(oinfo->dqi_gqinode)->ip_alloc_sem);
+               mutex_unlock(&oinfo->dqi_gqinode->i_mutex);
+       } else {
+               up_read(&OCFS2_I(oinfo->dqi_gqinode)->ip_alloc_sem);
+       }
        ocfs2_inode_unlock(oinfo->dqi_gqinode, ex);
        brelse(oinfo->dqi_gqi_bh);
        spin_lock(&dq_data_lock);
@@ -458,75 +473,6 @@ static int ocfs2_calc_global_qinit_credits(struct super_block *sb, int type)
                        OCFS2_QUOTA_BLOCK_UPDATE_CREDITS;
 }
 
-/* Read in information from global quota file and acquire a reference to it.
- * dquot_acquire() has already started the transaction and locked quota file */
-int ocfs2_global_read_dquot(struct dquot *dquot)
-{
-       int err, err2, ex = 0;
-       struct super_block *sb = dquot->dq_sb;
-       int type = dquot->dq_type;
-       struct ocfs2_mem_dqinfo *info = sb_dqinfo(sb, type)->dqi_priv;
-       struct ocfs2_super *osb = OCFS2_SB(sb);
-       struct inode *gqinode = info->dqi_gqinode;
-       int need_alloc = ocfs2_global_qinit_alloc(sb, type);
-       handle_t *handle = NULL;
-
-       err = ocfs2_qinfo_lock(info, 0);
-       if (err < 0)
-               goto out;
-       err = qtree_read_dquot(&info->dqi_gi, dquot);
-       if (err < 0)
-               goto out_qlock;
-       OCFS2_DQUOT(dquot)->dq_use_count++;
-       OCFS2_DQUOT(dquot)->dq_origspace = dquot->dq_dqb.dqb_curspace;
-       OCFS2_DQUOT(dquot)->dq_originodes = dquot->dq_dqb.dqb_curinodes;
-       ocfs2_qinfo_unlock(info, 0);
-
-       if (!dquot->dq_off) {   /* No real quota entry? */
-               ex = 1;
-               /*
-                * Add blocks to quota file before we start a transaction since
-                * locking allocators ranks above a transaction start
-                */
-               WARN_ON(journal_current_handle());
-               down_write(&OCFS2_I(gqinode)->ip_alloc_sem);
-               err = ocfs2_extend_no_holes(gqinode,
-                       gqinode->i_size + (need_alloc << sb->s_blocksize_bits),
-                       gqinode->i_size);
-               up_write(&OCFS2_I(gqinode)->ip_alloc_sem);
-               if (err < 0)
-                       goto out;
-       }
-
-       handle = ocfs2_start_trans(osb,
-                                  ocfs2_calc_global_qinit_credits(sb, type));
-       if (IS_ERR(handle)) {
-               err = PTR_ERR(handle);
-               goto out;
-       }
-       err = ocfs2_qinfo_lock(info, ex);
-       if (err < 0)
-               goto out_trans;
-       err = qtree_write_dquot(&info->dqi_gi, dquot);
-       if (ex && info_dirty(sb_dqinfo(dquot->dq_sb, dquot->dq_type))) {
-               err2 = __ocfs2_global_write_info(dquot->dq_sb, dquot->dq_type);
-               if (!err)
-                       err = err2;
-       }
-out_qlock:
-       if (ex)
-               ocfs2_qinfo_unlock(info, 1);
-       else
-               ocfs2_qinfo_unlock(info, 0);
-out_trans:
-       if (handle)
-               ocfs2_commit_trans(osb, handle);
-out:
-       if (err < 0)
-               mlog_errno(err);
-       return err;
-}
-
 /* Sync local information about quota modifications with global quota file.
  * Caller must have started the transaction and obtained exclusive lock for
  * global quota file inode */
@@ -742,6 +688,10 @@ static int ocfs2_release_dquot(struct dquot *dquot)
 
        mlog_entry("id=%u, type=%d", dquot->dq_id, dquot->dq_type);
 
+       mutex_lock(&dquot->dq_lock);
+       /* Check whether we are not racing with some other dqget() */
+       if (atomic_read(&dquot->dq_count) > 1)
+               goto out;
        status = ocfs2_lock_global_qf(oinfo, 1);
        if (status < 0)
                goto out;
@@ -752,30 +702,113 @@ static int ocfs2_release_dquot(struct dquot *dquot)
                mlog_errno(status);
                goto out_ilock;
        }
-       status = dquot_release(dquot);
+
+       status = ocfs2_global_release_dquot(dquot);
+       if (status < 0) {
+               mlog_errno(status);
+               goto out_trans;
+       }
+       status = ocfs2_local_release_dquot(handle, dquot);
+       /*
+        * If we fail here, we cannot do much as global structure is
+        * already released. So just complain...
+        */
+       if (status < 0)
+               mlog_errno(status);
+       clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
+out_trans:
        ocfs2_commit_trans(osb, handle);
 out_ilock:
        ocfs2_unlock_global_qf(oinfo, 1);
 out:
+       mutex_unlock(&dquot->dq_lock);
        mlog_exit(status);
        return status;
 }
 
+/*
+ * Read global dquot structure from disk or create it if it does
+ * not exist. Also update use count of the global structure and
+ * create structure in node-local quota file.
+ */
 static int ocfs2_acquire_dquot(struct dquot *dquot)
 {
-       struct ocfs2_mem_dqinfo *oinfo =
-                       sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
-       int status = 0;
+       int status = 0, err;
+       int ex = 0;
+       struct super_block *sb = dquot->dq_sb;
+       struct ocfs2_super *osb = OCFS2_SB(sb);
+       int type = dquot->dq_type;
+       struct ocfs2_mem_dqinfo *info = sb_dqinfo(sb, type)->dqi_priv;
+       struct inode *gqinode = info->dqi_gqinode;
+       int need_alloc = ocfs2_global_qinit_alloc(sb, type);
+       handle_t *handle;
 
-       mlog_entry("id=%u, type=%d", dquot->dq_id, dquot->dq_type);
-       /* We need an exclusive lock, because we're going to update use count
-        * and instantiate possibly new dquot structure */
-       status = ocfs2_lock_global_qf(oinfo, 1);
+       mlog_entry("id=%u, type=%d", dquot->dq_id, type);
+       mutex_lock(&dquot->dq_lock);
+       /*
+        * We need an exclusive lock, because we're going to update use count
+        * and instantiate possibly new dquot structure
+        */
+       status = ocfs2_lock_global_qf(info, 1);
        if (status < 0)
                goto out;
-       status = dquot_acquire(dquot);
-       ocfs2_unlock_global_qf(oinfo, 1);
+       if (!test_bit(DQ_READ_B, &dquot->dq_flags)) {
+               status = ocfs2_qinfo_lock(info, 0);
+               if (status < 0)
+                       goto out_dq;
+               status = qtree_read_dquot(&info->dqi_gi, dquot);
+               ocfs2_qinfo_unlock(info, 0);
+               if (status < 0)
+                       goto out_dq;
+       }
+       set_bit(DQ_READ_B, &dquot->dq_flags);
+
+       OCFS2_DQUOT(dquot)->dq_use_count++;
+       OCFS2_DQUOT(dquot)->dq_origspace = dquot->dq_dqb.dqb_curspace;
+       OCFS2_DQUOT(dquot)->dq_originodes = dquot->dq_dqb.dqb_curinodes;
+       if (!dquot->dq_off) {   /* No real quota entry? */
+               ex = 1;
+               /*
+                * Add blocks to quota file before we start a transaction since
+                * locking allocators ranks above a transaction start
+                */
+               WARN_ON(journal_current_handle());
+               status = ocfs2_extend_no_holes(gqinode,
+                       gqinode->i_size + (need_alloc << sb->s_blocksize_bits),
+                       gqinode->i_size);
+               if (status < 0)
+                       goto out_dq;
+       }
+
+       handle = ocfs2_start_trans(osb,
+                                  ocfs2_calc_global_qinit_credits(sb, type));
+       if (IS_ERR(handle)) {
+               status = PTR_ERR(handle);
+               goto out_dq;
+       }
+       status = ocfs2_qinfo_lock(info, ex);
+       if (status < 0)
+               goto out_trans;
+       status = qtree_write_dquot(&info->dqi_gi, dquot);
+       if (ex && info_dirty(sb_dqinfo(sb, type))) {
+               err = __ocfs2_global_write_info(sb, type);
+               if (!status)
+                       status = err;
+       }
+       ocfs2_qinfo_unlock(info, ex);
+out_trans:
+       ocfs2_commit_trans(osb, handle);
+out_dq:
+       ocfs2_unlock_global_qf(info, 1);
+       if (status < 0)
+               goto out;
+
+       status = ocfs2_create_local_dquot(dquot);
+       if (status < 0)
+               goto out;
+       set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
 out:
+       mutex_unlock(&dquot->dq_lock);
        mlog_exit(status);
        return status;
 }
@@ -820,7 +853,9 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
                mlog_errno(status);
                goto out_ilock;
        }
+       mutex_lock(&sb_dqopt(sb)->dqio_mutex);
        status = ocfs2_sync_dquot(dquot);
+       mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
index 962e838..778947f 100644 (file)
@@ -22,6 +22,7 @@
 #include "dlmglue.h"
 #include "quota.h"
 #include "uptodate.h"
+#include "super.h"
 
 /* Number of local quota structures per block */
 static inline unsigned int ol_quota_entries_per_block(struct super_block *sb)
@@ -129,6 +130,39 @@ static int ocfs2_modify_bh(struct inode *inode, struct buffer_head *bh,
        return 0;
 }
 
+/*
+ * Read quota block from a given logical offset.
+ *
+ * This function acquires ip_alloc_sem and thus it must not be called with a
+ * transaction started.
+ */
+static int ocfs2_read_quota_block(struct inode *inode, u64 v_block,
+                                 struct buffer_head **bh)
+{
+       int rc = 0;
+       struct buffer_head *tmp = *bh;
+
+       if (i_size_read(inode) >> inode->i_sb->s_blocksize_bits <= v_block) {
+               ocfs2_error(inode->i_sb,
+                           "Quota file %llu is probably corrupted! Requested "
+                           "to read block %Lu but file has size only %Lu\n",
+                           (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                           (unsigned long long)v_block,
+                           (unsigned long long)i_size_read(inode));
+               return -EIO;
+       }
+       rc = ocfs2_read_virt_blocks(inode, v_block, 1, &tmp, 0,
+                                   ocfs2_validate_quota_block);
+       if (rc)
+               mlog_errno(rc);
+
+       /* If ocfs2_read_virt_blocks() got us a new bh, pass it up. */
+       if (!rc && !*bh)
+               *bh = tmp;
+
+       return rc;
+}
+
 /* Check whether we understand format of quota files */
 static int ocfs2_local_check_quota_file(struct super_block *sb, int type)
 {
@@ -972,10 +1006,8 @@ static struct ocfs2_quota_chunk *ocfs2_local_quota_add_chunk(
        }
 
        /* Initialize chunk header */
-       down_read(&OCFS2_I(lqinode)->ip_alloc_sem);
        status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks,
                                             &p_blkno, NULL, NULL);
-       up_read(&OCFS2_I(lqinode)->ip_alloc_sem);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
@@ -1003,10 +1035,8 @@ static struct ocfs2_quota_chunk *ocfs2_local_quota_add_chunk(
        ocfs2_journal_dirty(handle, bh);
 
        /* Initialize new block with structures */
-       down_read(&OCFS2_I(lqinode)->ip_alloc_sem);
        status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks + 1,
                                             &p_blkno, NULL, NULL);
-       up_read(&OCFS2_I(lqinode)->ip_alloc_sem);
        if (status < 0) {
                mlog_errno(status);
                goto out_trans;
@@ -1103,10 +1133,8 @@ static struct ocfs2_quota_chunk *ocfs2_extend_local_quota_file(
        }
 
        /* Get buffer from the just added block */
-       down_read(&OCFS2_I(lqinode)->ip_alloc_sem);
        status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks,
                                             &p_blkno, NULL, NULL);
-       up_read(&OCFS2_I(lqinode)->ip_alloc_sem);
        if (status < 0) {
                mlog_errno(status);
                goto out;
@@ -1187,7 +1215,7 @@ static void olq_alloc_dquot(struct buffer_head *bh, void *private)
 }
 
 /* Create dquot in the local file for given id */
-static int ocfs2_create_local_dquot(struct dquot *dquot)
+int ocfs2_create_local_dquot(struct dquot *dquot)
 {
        struct super_block *sb = dquot->dq_sb;
        int type = dquot->dq_type;
@@ -1237,36 +1265,11 @@ out:
        return status;
 }
 
-/* Create entry in local file for dquot, load data from the global file */
-static int ocfs2_local_read_dquot(struct dquot *dquot)
-{
-       int status;
-
-       mlog_entry("id=%u, type=%d\n", dquot->dq_id, dquot->dq_type);
-
-       status = ocfs2_global_read_dquot(dquot);
-       if (status < 0) {
-               mlog_errno(status);
-               goto out_err;
-       }
-
-       /* Now create entry in the local quota file */
-       status = ocfs2_create_local_dquot(dquot);
-       if (status < 0) {
-               mlog_errno(status);
-               goto out_err;
-       }
-       mlog_exit(0);
-       return 0;
-out_err:
-       mlog_exit(status);
-       return status;
-}
-
-/* Release dquot structure from local quota file. ocfs2_release_dquot() has
- * already started a transaction and obtained exclusive lock for global
- * quota file. */
-static int ocfs2_local_release_dquot(struct dquot *dquot)
+/*
+ * Release dquot structure from local quota file. ocfs2_release_dquot() has
+ * already started a transaction and written all changes to global quota file
+ */
+int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot)
 {
        int status;
        int type = dquot->dq_type;
@@ -1274,15 +1277,6 @@ static int ocfs2_local_release_dquot(struct dquot *dquot)
        struct super_block *sb = dquot->dq_sb;
        struct ocfs2_local_disk_chunk *dchunk;
        int offset;
-       handle_t *handle = journal_current_handle();
-
-       BUG_ON(!handle);
-       /* First write all local changes to global file */
-       status = ocfs2_global_release_dquot(dquot);
-       if (status < 0) {
-               mlog_errno(status);
-               goto out;
-       }
 
        status = ocfs2_journal_access_dq(handle,
                        INODE_CACHE(sb_dqopt(sb)->files[type]),
@@ -1315,9 +1309,7 @@ static const struct quota_format_ops ocfs2_format_ops = {
        .read_file_info         = ocfs2_local_read_info,
        .write_file_info        = ocfs2_global_write_info,
        .free_file_info         = ocfs2_local_free_info,
-       .read_dqblk             = ocfs2_local_read_dquot,
        .commit_dqblk           = ocfs2_local_write_dquot,
-       .release_dqblk          = ocfs2_local_release_dquot,
 };
 
 struct quota_format_type ocfs2_quota_format = {