1 files changed, 303 insertions, 133 deletions

diff --git a/fs/dquot.c b/fs/dquot.c
index c237ccc8581c..61bfff64e5af 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -211,8 +211,6 @@ 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)
 {
@@ -415,6 +413,17 @@ out_dqlock:
         return ret;
 }
 
+void dquot_destroy(struct dquot *dquot)
+{
+        kmem_cache_free(dquot_cachep, dquot);
+}
+EXPORT_SYMBOL(dquot_destroy);
+
+static inline void do_destroy_dquot(struct dquot *dquot)
+{
+        dquot->dq_sb->dq_op->destroy_dquot(dquot);
+}
+
 /* Invalidate all dquots on the list. Note that this function is called after
  * quota is disabled and pointers from inodes removed so there cannot be new
  * quota users. There can still be some users of quotas due to inodes being
@@ -463,9 +472,44 @@ restart:
                 remove_dquot_hash(dquot);
                 remove_free_dquot(dquot);
                 remove_inuse(dquot);
-                kmem_cache_free(dquot_cachep, dquot);
+                do_destroy_dquot(dquot);
+        }
+        spin_unlock(&dq_list_lock);
+}
+
+/* Call callback for every active dquot on given filesystem */
+int dquot_scan_active(struct super_block *sb,
+                      int (*fn)(struct dquot *dquot, unsigned long priv),
+                      unsigned long priv)
+{
+        struct dquot *dquot, *old_dquot = NULL;
+        int ret = 0;
+
+        mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+        spin_lock(&dq_list_lock);
+        list_for_each_entry(dquot, &inuse_list, dq_inuse) {
+                if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+                        continue;
+                if (dquot->dq_sb != sb)
+                        continue;
+                /* Now we have active dquot so we can just increase use count */
+                atomic_inc(&dquot->dq_count);
+                dqstats.lookups++;
+                spin_unlock(&dq_list_lock);
+                dqput(old_dquot);
+                old_dquot = dquot;
+                ret = fn(dquot, priv);
+                if (ret < 0)
+                        goto out;
+                spin_lock(&dq_list_lock);
+                /* We are safe to continue now because our dquot could not
+                 * be moved out of the inuse list while we hold the reference */
         }
         spin_unlock(&dq_list_lock);
+out:
+        dqput(old_dquot);
+        mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+        return ret;
 }
 
 int vfs_quota_sync(struct super_block *sb, int type)
@@ -479,7 +523,7 @@ int vfs_quota_sync(struct super_block *sb, int type)
         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
                 if (type != -1 && cnt != type)
                         continue;
-                if (!sb_has_quota_enabled(sb, cnt))
+                if (!sb_has_quota_active(sb, cnt))
                         continue;
                 spin_lock(&dq_list_lock);
                 dirty = &dqopt->info[cnt].dqi_dirty_list;
@@ -504,8 +548,8 @@ int vfs_quota_sync(struct super_block *sb, int type)
         }
 
         for (cnt = 0; cnt < MAXQUOTAS; cnt++)
-                if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt)
-                        && info_dirty(&dqopt->info[cnt]))
+                if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt)
+                    && info_dirty(&dqopt->info[cnt]))
                         sb->dq_op->write_info(sb, cnt);
         spin_lock(&dq_list_lock);
         dqstats.syncs++;
@@ -527,7 +571,7 @@ static void prune_dqcache(int count)
                 remove_dquot_hash(dquot);
                 remove_free_dquot(dquot);
                 remove_inuse(dquot);
-                kmem_cache_free(dquot_cachep, dquot);
+                do_destroy_dquot(dquot);
                 count--;
                 head = free_dquots.prev;
         }
@@ -558,7 +602,7 @@ static struct shrinker dqcache_shrinker = {
  * NOTE: If you change this function please check whether dqput_blocks() works right...
  * MUST be called with either dqptr_sem or dqonoff_mutex held
  */
-static void dqput(struct dquot *dquot)
+void dqput(struct dquot *dquot)
 {
         int ret;
 
@@ -584,7 +628,7 @@ we_slept:
                 /* We have more than one user... nothing to do */
                 atomic_dec(&dquot->dq_count);
                 /* Releasing dquot during quotaoff phase? */
-                if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) &&
+                if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) &&
                     atomic_read(&dquot->dq_count) == 1)
                         wake_up(&dquot->dq_wait_unused);
                 spin_unlock(&dq_list_lock);
@@ -625,11 +669,17 @@ we_slept:
         spin_unlock(&dq_list_lock);
 }
 
+struct dquot *dquot_alloc(struct super_block *sb, int type)
+{
+        return kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
+}
+EXPORT_SYMBOL(dquot_alloc);
+
 static struct dquot *get_empty_dquot(struct super_block *sb, int type)
 {
         struct dquot *dquot;
 
-        dquot = kmem_cache_zalloc(dquot_cachep, GFP_NOFS);
+        dquot = sb->dq_op->alloc_dquot(sb, type);
         if(!dquot)
                 return NODQUOT;
 
@@ -647,15 +697,33 @@ static struct dquot *get_empty_dquot(struct super_block *sb, int type)
 }
 
 /*
+ * Check whether dquot is in memory.
+ * MUST be called with either dqptr_sem or dqonoff_mutex held
+ */
+int dquot_is_cached(struct super_block *sb, unsigned int id, int type)
+{
+        unsigned int hashent = hashfn(sb, id, type);
+        int ret = 0;
+
+        if (!sb_has_quota_active(sb, type))
+                return 0;
+        spin_lock(&dq_list_lock);
+        if (find_dquot(hashent, sb, id, type) != NODQUOT)
+                ret = 1;
+        spin_unlock(&dq_list_lock);
+        return ret;
+}
+
+/*
  * Get reference to dquot
  * MUST be called with either dqptr_sem or dqonoff_mutex held
  */
-static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
+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))
+        if (!sb_has_quota_active(sb, type))
                 return NODQUOT;
 we_slept:
         spin_lock(&dq_list_lock);
@@ -682,7 +750,7 @@ we_slept:
                 dqstats.lookups++;
                 spin_unlock(&dq_list_lock);
                 if (empty)
-                        kmem_cache_free(dquot_cachep, empty);
+                        do_destroy_dquot(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 */
@@ -820,7 +888,7 @@ static void drop_dquot_ref(struct super_block *sb, int type)
         }
 }
 
-static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
+static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number)
 {
         dquot->dq_dqb.dqb_curinodes += number;
 }
@@ -830,9 +898,10 @@ 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)
+static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
 {
-        if (dquot->dq_dqb.dqb_curinodes > number)
+        if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
+            dquot->dq_dqb.dqb_curinodes >= number)
                 dquot->dq_dqb.dqb_curinodes -= number;
         else
                 dquot->dq_dqb.dqb_curinodes = 0;
@@ -843,11 +912,12 @@ static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
 
 static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
 {
-        if (dquot->dq_dqb.dqb_curspace > number)
+        if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
+            dquot->dq_dqb.dqb_curspace >= number)
                 dquot->dq_dqb.dqb_curspace -= number;
         else
                 dquot->dq_dqb.dqb_curspace = 0;
-        if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
+        if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
                 dquot->dq_dqb.dqb_btime = (time_t) 0;
         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
 }
@@ -1023,10 +1093,11 @@ static inline char ignore_hardlimit(struct dquot *dquot)
 }
 
 /* needs dq_data_lock */
-static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
+static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype)
 {
         *warntype = QUOTA_NL_NOWARN;
-        if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
+        if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
+            test_bit(DQ_FAKE_B, &dquot->dq_flags))
                 return QUOTA_OK;
 
         if (dquot->dq_dqb.dqb_ihardlimit &&
@@ -1058,11 +1129,12 @@ static int check_idq(struct dquot *dquot, ulong inodes, char *warntype)
 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype)
 {
         *warntype = QUOTA_NL_NOWARN;
-        if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags))
+        if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) ||
+            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 &&
+            dquot->dq_dqb.dqb_curspace + space > dquot->dq_dqb.dqb_bhardlimit &&
             !ignore_hardlimit(dquot)) {
                 if (!prealloc)
                         *warntype = QUOTA_NL_BHARDWARN;
@@ -1070,7 +1142,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *war
         }
 
         if (dquot->dq_dqb.dqb_bsoftlimit &&
-           toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
+            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)
@@ -1079,7 +1151,7 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *war
         }
 
         if (dquot->dq_dqb.dqb_bsoftlimit &&
-           toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit &&
+            dquot->dq_dqb.dqb_curspace + space > dquot->dq_dqb.dqb_bsoftlimit &&
             dquot->dq_dqb.dqb_btime == 0) {
                 if (!prealloc) {
                         *warntype = QUOTA_NL_BSOFTWARN;
@@ -1096,10 +1168,11 @@ static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *war
         return QUOTA_OK;
 }
 
-static int info_idq_free(struct dquot *dquot, ulong inodes)
+static int info_idq_free(struct dquot *dquot, qsize_t inodes)
 {
         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
-            dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit)
+            dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit ||
+            !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type))
                 return QUOTA_NL_NOWARN;
 
         if (dquot->dq_dqb.dqb_curinodes - inodes <= dquot->dq_dqb.dqb_isoftlimit)
@@ -1113,15 +1186,13 @@ static int info_idq_free(struct dquot *dquot, ulong inodes)
 static int info_bdq_free(struct dquot *dquot, qsize_t space)
 {
         if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
-            toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit)
+            dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit)
                 return QUOTA_NL_NOWARN;
 
-        if (toqb(dquot->dq_dqb.dqb_curspace - space) <=
-            dquot->dq_dqb.dqb_bsoftlimit)
+        if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit)
                 return QUOTA_NL_BSOFTBELOW;
-        if (toqb(dquot->dq_dqb.dqb_curspace) >= dquot->dq_dqb.dqb_bhardlimit &&
-            toqb(dquot->dq_dqb.dqb_curspace - space) <
-                                                dquot->dq_dqb.dqb_bhardlimit)
+        if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit &&
+            dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit)
                 return QUOTA_NL_BHARDBELOW;
         return QUOTA_NL_NOWARN;
 }
@@ -1166,17 +1237,23 @@ out_err:
  *      Release all quotas referenced by inode
  *      Transaction must be started at an entry
  */
-int dquot_drop(struct inode *inode)
+int dquot_drop_locked(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;
                 }
         }
+        return 0;
+}
+
+int dquot_drop(struct inode *inode)
+{
+        down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+        dquot_drop_locked(inode);
         up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
         return 0;
 }
@@ -1264,7 +1341,7 @@ warn_put_all:
 /*
  * This operation can block, but only after everything is updated
  */
-int dquot_alloc_inode(const struct inode *inode, unsigned long number)
+int dquot_alloc_inode(const struct inode *inode, qsize_t number)
 {
         int cnt, ret = NO_QUOTA;
         char warntype[MAXQUOTAS];
@@ -1349,7 +1426,7 @@ out_sub:
 /*
  * This operation can block, but only after everything is updated
  */
-int dquot_free_inode(const struct inode *inode, unsigned long number)
+int dquot_free_inode(const struct inode *inode, qsize_t number)
 {
         unsigned int cnt;
         char warntype[MAXQUOTAS];
@@ -1495,7 +1572,7 @@ warn_put_all:
 /* Wrapper for transferring ownership of an inode */
 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr)
 {
-        if (sb_any_quota_enabled(inode->i_sb) && !IS_NOQUOTA(inode)) {
+        if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) {
                 vfs_dq_init(inode);
                 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA)
                         return 1;
@@ -1533,54 +1610,27 @@ struct dquot_operations dquot_operations = {
         .acquire_dquot  = dquot_acquire,
         .release_dquot  = dquot_release,
         .mark_dirty     = dquot_mark_dquot_dirty,
-        .write_info     = dquot_commit_info
+        .write_info     = dquot_commit_info,
+        .alloc_dquot    = dquot_alloc,
+        .destroy_dquot  = dquot_destroy,
 };
 
-static inline void set_enable_flags(struct quota_info *dqopt, int type)
-{
-        switch (type) {
-                case USRQUOTA:
-                        dqopt->flags |= DQUOT_USR_ENABLED;
-                        dqopt->flags &= ~DQUOT_USR_SUSPENDED;
-                        break;
-                case GRPQUOTA:
-                        dqopt->flags |= DQUOT_GRP_ENABLED;
-                        dqopt->flags &= ~DQUOT_GRP_SUSPENDED;
-                        break;
-        }
-}
-
-static inline void reset_enable_flags(struct quota_info *dqopt, int type,
-                                      int remount)
-{
-        switch (type) {
-                case USRQUOTA:
-                        dqopt->flags &= ~DQUOT_USR_ENABLED;
-                        if (remount)
-                                dqopt->flags |= DQUOT_USR_SUSPENDED;
-                        else
-                                dqopt->flags &= ~DQUOT_USR_SUSPENDED;
-                        break;
-                case GRPQUOTA:
-                        dqopt->flags &= ~DQUOT_GRP_ENABLED;
-                        if (remount)
-                                dqopt->flags |= DQUOT_GRP_SUSPENDED;
-                        else
-                                dqopt->flags &= ~DQUOT_GRP_SUSPENDED;
-                        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 remount)
+int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
 {
         int cnt, ret = 0;
         struct quota_info *dqopt = sb_dqopt(sb);
         struct inode *toputinode[MAXQUOTAS];
 
+        /* Cannot turn off usage accounting without turning off limits, or
+         * suspend quotas and simultaneously turn quotas off. */
+        if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED))
+            || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED |
+            DQUOT_USAGE_ENABLED)))
+                return -EINVAL;
+
         /* We need to serialize quota_off() for device */
         mutex_lock(&dqopt->dqonoff_mutex);
 
@@ -1589,7 +1639,7 @@ int vfs_quota_off(struct super_block *sb, int type, int remount)
          * sometimes we are called when fill_super() failed and calling
          * sync_fs() in such cases does no good.
          */
-        if (!sb_any_quota_enabled(sb) && !sb_any_quota_suspended(sb)) {
+        if (!sb_any_quota_loaded(sb)) {
                 mutex_unlock(&dqopt->dqonoff_mutex);
                 return 0;
         }
@@ -1597,17 +1647,28 @@ int vfs_quota_off(struct super_block *sb, int type, int remount)
                 toputinode[cnt] = NULL;
                 if (type != -1 && cnt != type)
                         continue;
-                /* If we keep inodes of quota files after remount and quotaoff
-                 * is called, drop kept inodes. */
-                if (!remount && sb_has_quota_suspended(sb, cnt)) {
-                        iput(dqopt->files[cnt]);
-                        dqopt->files[cnt] = NULL;
-                        reset_enable_flags(dqopt, cnt, 0);
+                if (!sb_has_quota_loaded(sb, cnt))
                         continue;
+
+                if (flags & DQUOT_SUSPENDED) {
+                        dqopt->flags |=
+                                dquot_state_flag(DQUOT_SUSPENDED, cnt);
+                } else {
+                        dqopt->flags &= ~dquot_state_flag(flags, cnt);
+                        /* Turning off suspended quotas? */
+                        if (!sb_has_quota_loaded(sb, cnt) &&
+                            sb_has_quota_suspended(sb, cnt)) {
+                                dqopt->flags &= ~dquot_state_flag(
+                                                        DQUOT_SUSPENDED, cnt);
+                                iput(dqopt->files[cnt]);
+                                dqopt->files[cnt] = NULL;
+                                continue;
+                        }
                 }
-                if (!sb_has_quota_enabled(sb, cnt))
+
+                /* We still have to keep quota loaded? */
+                if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED))
                         continue;
-                reset_enable_flags(dqopt, cnt, remount);
 
                 /* Note: these are blocking operations */
                 drop_dquot_ref(sb, cnt);
@@ -1623,7 +1684,7 @@ int vfs_quota_off(struct super_block *sb, int type, int remount)
                 put_quota_format(dqopt->info[cnt].dqi_format);
 
                 toputinode[cnt] = dqopt->files[cnt];
-                if (!remount)
+                if (!sb_has_quota_loaded(sb, cnt))
                         dqopt->files[cnt] = NULL;
                 dqopt->info[cnt].dqi_flags = 0;
                 dqopt->info[cnt].dqi_igrace = 0;
@@ -1631,6 +1692,11 @@ int vfs_quota_off(struct super_block *sb, int type, int remount)
                 dqopt->ops[cnt] = NULL;
         }
         mutex_unlock(&dqopt->dqonoff_mutex);
+
+        /* Skip syncing and setting flags if quota files are hidden */
+        if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
+                goto put_inodes;
+
         /* Sync the superblock so that buffers with quota data are written to
          * disk (and so userspace sees correct data afterwards). */
         if (sb->s_op->sync_fs)
@@ -1646,7 +1712,7 @@ int vfs_quota_off(struct super_block *sb, int type, int remount)
                         mutex_lock(&dqopt->dqonoff_mutex);
                         /* If quota was reenabled in the meantime, we have
                          * nothing to do */
-                        if (!sb_has_quota_enabled(sb, cnt)) {
+                        if (!sb_has_quota_loaded(sb, cnt)) {
                                 mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA);
                                 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
                                   S_NOATIME | S_NOQUOTA);
@@ -1655,26 +1721,43 @@ int vfs_quota_off(struct super_block *sb, int type, int remount)
                                 mark_inode_dirty(toputinode[cnt]);
                         }
                         mutex_unlock(&dqopt->dqonoff_mutex);
+                }
+        if (sb->s_bdev)
+                invalidate_bdev(sb->s_bdev);
+put_inodes:
+        for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+                if (toputinode[cnt]) {
                         /* On remount RO, we keep the inode pointer so that we
-                         * can reenable quota on the subsequent remount RW.
-                         * But we have better not keep inode pointer when there
-                         * is pending delete on the quota file... */
-                        if (!remount)
+                         * can reenable quota on the subsequent remount RW. We
+                         * have to check 'flags' variable and not use sb_has_
+                         * function because another quotaon / quotaoff could
+                         * change global state before we got here. We refuse
+                         * to suspend quotas when there is pending delete on
+                         * the quota file... */
+                        if (!(flags & DQUOT_SUSPENDED))
                                 iput(toputinode[cnt]);
                         else if (!toputinode[cnt]->i_nlink)
                                 ret = -EBUSY;
                 }
-        if (sb->s_bdev)
-                invalidate_bdev(sb->s_bdev);
         return ret;
 }
 
+int vfs_quota_off(struct super_block *sb, int type, int remount)
+{
+        return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED :
+                                 (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED));
+}
+
 /*
  *      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)
+/*
+ * Helper function to turn quotas on when we already have the inode of
+ * quota file and no quota information is loaded.
+ */
+static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
+        unsigned int flags)
 {
         struct quota_format_type *fmt = find_quota_format(format_id);
         struct super_block *sb = inode->i_sb;
@@ -1696,27 +1779,37 @@ static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
                 error = -EINVAL;
                 goto out_fmt;
         }
+        /* Usage always has to be set... */
+        if (!(flags & DQUOT_USAGE_ENABLED)) {
+                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);
+        if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+                /* 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);
+        }
         mutex_lock(&inode->i_mutex);
         mutex_lock(&dqopt->dqonoff_mutex);
-        if (sb_has_quota_enabled(sb, type) ||
-                        sb_has_quota_suspended(sb, type)) {
+        if (sb_has_quota_loaded(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);
-        sb->dq_op->drop(inode);
+
+        if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
+                /* We don't want quota and atime on quota files (deadlocks
+                 * possible) Also nobody should write to the file - we use
+                 * special IO operations which ignore the immutable bit. */
+                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);
+                sb->dq_op->drop(inode);
+        }
 
         error = -EIO;
         dqopt->files[type] = igrab(inode);
@@ -1737,7 +1830,7 @@ static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
         }
         mutex_unlock(&dqopt->dqio_mutex);
         mutex_unlock(&inode->i_mutex);
-        set_enable_flags(dqopt, type);
+        dqopt->flags |= dquot_state_flag(flags, type);
 
         add_dquot_ref(sb, type);
         mutex_unlock(&dqopt->dqonoff_mutex);
@@ -1770,20 +1863,23 @@ static int vfs_quota_on_remount(struct super_block *sb, int type)
         struct quota_info *dqopt = sb_dqopt(sb);
         struct inode *inode;
         int ret;
+        unsigned int flags;
 
         mutex_lock(&dqopt->dqonoff_mutex);
         if (!sb_has_quota_suspended(sb, type)) {
                 mutex_unlock(&dqopt->dqonoff_mutex);
                 return 0;
         }
-        BUG_ON(sb_has_quota_enabled(sb, type));
-
         inode = dqopt->files[type];
         dqopt->files[type] = NULL;
-        reset_enable_flags(dqopt, type, 0);
+        flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
+                                                DQUOT_LIMITS_ENABLED, type);
+        dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
         mutex_unlock(&dqopt->dqonoff_mutex);
 
-        ret = vfs_quota_on_inode(inode, type, dqopt->info[type].dqi_fmt_id);
+        flags = dquot_generic_flag(flags, type);
+        ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id,
+                                   flags);
         iput(inode);
 
         return ret;
@@ -1799,12 +1895,12 @@ int vfs_quota_on_path(struct super_block *sb, int type, int format_id,
         if (path->mnt->mnt_sb != sb)
                 error = -EXDEV;
         else
-                error = vfs_quota_on_inode(path->dentry->d_inode, type,
-                                           format_id);
+                error = vfs_load_quota_inode(path->dentry->d_inode, type,
+                                             format_id, DQUOT_USAGE_ENABLED |
+                                             DQUOT_LIMITS_ENABLED);
         return error;
 }
 
-/* Actual function called from quotactl() */
 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
                  int remount)
 {
@@ -1823,6 +1919,50 @@ int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name,
 }
 
 /*
+ * More powerful function for turning on quotas allowing setting
+ * of individual quota flags
+ */
+int vfs_quota_enable(struct inode *inode, int type, int format_id,
+                unsigned int flags)
+{
+        int ret = 0;
+        struct super_block *sb = inode->i_sb;
+        struct quota_info *dqopt = sb_dqopt(sb);
+
+        /* Just unsuspend quotas? */
+        if (flags & DQUOT_SUSPENDED)
+                return vfs_quota_on_remount(sb, type);
+        if (!flags)
+                return 0;
+        /* Just updating flags needed? */
+        if (sb_has_quota_loaded(sb, type)) {
+                mutex_lock(&dqopt->dqonoff_mutex);
+                /* Now do a reliable test... */
+                if (!sb_has_quota_loaded(sb, type)) {
+                        mutex_unlock(&dqopt->dqonoff_mutex);
+                        goto load_quota;
+                }
+                if (flags & DQUOT_USAGE_ENABLED &&
+                    sb_has_quota_usage_enabled(sb, type)) {
+                        ret = -EBUSY;
+                        goto out_lock;
+                }
+                if (flags & DQUOT_LIMITS_ENABLED &&
+                    sb_has_quota_limits_enabled(sb, type)) {
+                        ret = -EBUSY;
+                        goto out_lock;
+                }
+                sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
+out_lock:
+                mutex_unlock(&dqopt->dqonoff_mutex);
+                return ret;
+        }
+
+load_quota:
+        return vfs_load_quota_inode(inode, type, format_id, flags);
+}
+
+/*
  * This function is used when filesystem needs to initialize quotas
  * during mount time.
  */
@@ -1843,7 +1983,8 @@ int vfs_quota_on_mount(struct super_block *sb, char *qf_name,
 
         error = security_quota_on(dentry);
         if (!error)
-                error = vfs_quota_on_inode(dentry->d_inode, type, format_id);
+                error = vfs_load_quota_inode(dentry->d_inode, type, format_id,
+                                DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 
 out:
         dput(dentry);
@@ -1866,14 +2007,24 @@ int vfs_dq_quota_on_remount(struct super_block *sb)
         return ret;
 }
 
+static inline qsize_t qbtos(qsize_t blocks)
+{
+        return blocks << QIF_DQBLKSIZE_BITS;
+}
+
+static inline qsize_t stoqb(qsize_t space)
+{
+        return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
+}
+
 /* Generic routine for getting common part of quota structure */
 static void do_get_dqblk(struct dquot *dquot, struct 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_bhardlimit = stoqb(dm->dqb_bhardlimit);
+        di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit);
         di->dqb_curspace = dm->dqb_curspace;
         di->dqb_ihardlimit = dm->dqb_ihardlimit;
         di->dqb_isoftlimit = dm->dqb_isoftlimit;
@@ -1918,28 +2069,36 @@ static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di)
         if (di->dqb_valid & QIF_SPACE) {
                 dm->dqb_curspace = di->dqb_curspace;
                 check_blim = 1;
+                __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
         }
         if (di->dqb_valid & QIF_BLIMITS) {
-                dm->dqb_bsoftlimit = di->dqb_bsoftlimit;
-                dm->dqb_bhardlimit = di->dqb_bhardlimit;
+                dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);
+                dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);
                 check_blim = 1;
+                __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
         }
         if (di->dqb_valid & QIF_INODES) {
                 dm->dqb_curinodes = di->dqb_curinodes;
                 check_ilim = 1;
+                __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
         }
         if (di->dqb_valid & QIF_ILIMITS) {
                 dm->dqb_isoftlimit = di->dqb_isoftlimit;
                 dm->dqb_ihardlimit = di->dqb_ihardlimit;
                 check_ilim = 1;
+                __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
         }
-        if (di->dqb_valid & QIF_BTIME)
+        if (di->dqb_valid & QIF_BTIME) {
                 dm->dqb_btime = di->dqb_btime;
-        if (di->dqb_valid & QIF_ITIME)
+                __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
+        }
+        if (di->dqb_valid & QIF_ITIME) {
                 dm->dqb_itime = di->dqb_itime;
+                __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
+        }
 
         if (check_blim) {
-                if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) {
+                if (!dm->dqb_bsoftlimit || dm->dqb_curspace < dm->dqb_bsoftlimit) {
                         dm->dqb_btime = 0;
                         clear_bit(DQ_BLKS_B, &dquot->dq_flags);
                 }
@@ -1970,12 +2129,14 @@ int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *d
         int rc;
 
         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
-        if (!(dquot = dqget(sb, id, type))) {
-                mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
-                return -ESRCH;
+        dquot = dqget(sb, id, type);
+        if (!dquot) {
+                rc = -ESRCH;
+                goto out;
         }
         rc = do_set_dqblk(dquot, di);
         dqput(dquot);
+out:
         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
         return rc;
 }
@@ -1986,7 +2147,7 @@ int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
         struct mem_dqinfo *mi;
   
         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
-        if (!sb_has_quota_enabled(sb, type)) {
+        if (!sb_has_quota_active(sb, type)) {
                 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
                 return -ESRCH;
         }
@@ -2005,11 +2166,12 @@ int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
 {
         struct mem_dqinfo *mi;
+        int err = 0;
 
         mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
-        if (!sb_has_quota_enabled(sb, type)) {
-                mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
-                return -ESRCH;
+        if (!sb_has_quota_active(sb, type)) {
+                err = -ESRCH;
+                goto out;
         }
         mi = sb_dqopt(sb)->info + type;
         spin_lock(&dq_data_lock);
@@ -2023,8 +2185,9 @@ int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
         mark_info_dirty(sb, type);
         /* Force write to disk */
         sb->dq_op->write_info(sb, type);
+out:
         mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
-        return 0;
+        return err;
 }
 
 struct quotactl_ops vfs_quotactl_ops = {
@@ -2186,10 +2349,13 @@ EXPORT_SYMBOL(register_quota_format);
 EXPORT_SYMBOL(unregister_quota_format);
 EXPORT_SYMBOL(dqstats);
 EXPORT_SYMBOL(dq_data_lock);
+EXPORT_SYMBOL(vfs_quota_enable);
 EXPORT_SYMBOL(vfs_quota_on);
 EXPORT_SYMBOL(vfs_quota_on_path);
 EXPORT_SYMBOL(vfs_quota_on_mount);
+EXPORT_SYMBOL(vfs_quota_disable);
 EXPORT_SYMBOL(vfs_quota_off);
+EXPORT_SYMBOL(dquot_scan_active);
 EXPORT_SYMBOL(vfs_quota_sync);
 EXPORT_SYMBOL(vfs_get_dqinfo);
 EXPORT_SYMBOL(vfs_set_dqinfo);
@@ -2202,7 +2368,11 @@ EXPORT_SYMBOL(dquot_release);
 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
 EXPORT_SYMBOL(dquot_initialize);
 EXPORT_SYMBOL(dquot_drop);
+EXPORT_SYMBOL(dquot_drop_locked);
 EXPORT_SYMBOL(vfs_dq_drop);
+EXPORT_SYMBOL(dqget);
+EXPORT_SYMBOL(dqput);
+EXPORT_SYMBOL(dquot_is_cached);
 EXPORT_SYMBOL(dquot_alloc_space);
 EXPORT_SYMBOL(dquot_alloc_inode);
 EXPORT_SYMBOL(dquot_free_space);