1 files changed, 259 insertions, 64 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d8759401ecae..2d51cd9af225 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -74,7 +74,6 @@ static const char *ext4_decode_error(struct super_block *sb, int errno,
 static int ext4_remount(struct super_block *sb, int *flags, char *data);
 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
 static int ext4_unfreeze(struct super_block *sb);
-static void ext4_write_super(struct super_block *sb);
 static int ext4_freeze(struct super_block *sb);
 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
                        const char *dev_name, void *data);
@@ -896,7 +895,7 @@ static void ext4_put_super(struct super_block *sb)
                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
                 es->s_state = cpu_to_le16(sbi->s_mount_state);
         }
-        if (sb->s_dirt || !(sb->s_flags & MS_RDONLY))
+        if (!(sb->s_flags & MS_RDONLY))
                 ext4_commit_super(sb, 1);
 
         if (sbi->s_proc) {
@@ -1137,12 +1136,18 @@ static int ext4_mark_dquot_dirty(struct dquot *dquot);
 static int ext4_write_info(struct super_block *sb, int type);
 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
                          struct path *path);
+static int ext4_quota_on_sysfile(struct super_block *sb, int type,
+                                 int format_id);
 static int ext4_quota_off(struct super_block *sb, int type);
+static int ext4_quota_off_sysfile(struct super_block *sb, int type);
 static int ext4_quota_on_mount(struct super_block *sb, int type);
 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
                                size_t len, loff_t off);
 static ssize_t ext4_quota_write(struct super_block *sb, int type,
                                 const char *data, size_t len, loff_t off);
+static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
+                             unsigned int flags);
+static int ext4_enable_quotas(struct super_block *sb);
 
 static const struct dquot_operations ext4_quota_operations = {
         .get_reserved_space = ext4_get_reserved_space,
@@ -1164,6 +1169,16 @@ static const struct quotactl_ops ext4_qctl_operations = {
         .get_dqblk      = dquot_get_dqblk,
         .set_dqblk      = dquot_set_dqblk
 };
+
+static const struct quotactl_ops ext4_qctl_sysfile_operations = {
+        .quota_on_meta  = ext4_quota_on_sysfile,
+        .quota_off      = ext4_quota_off_sysfile,
+        .quota_sync     = dquot_quota_sync,
+        .get_info       = dquot_get_dqinfo,
+        .set_info       = dquot_set_dqinfo,
+        .get_dqblk      = dquot_get_dqblk,
+        .set_dqblk      = dquot_set_dqblk
+};
 #endif
 
 static const struct super_operations ext4_sops = {
@@ -1194,7 +1209,6 @@ static const struct super_operations ext4_nojournal_sops = {
         .dirty_inode    = ext4_dirty_inode,
         .drop_inode     = ext4_drop_inode,
         .evict_inode    = ext4_evict_inode,
-        .write_super    = ext4_write_super,
         .put_super      = ext4_put_super,
         .statfs         = ext4_statfs,
         .remount_fs     = ext4_remount,
@@ -2661,6 +2675,16 @@ static int ext4_feature_set_ok(struct super_block *sb, int readonly)
                          "extents feature\n");
                 return 0;
         }
+
+#ifndef CONFIG_QUOTA
+        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
+            !readonly) {
+                ext4_msg(sb, KERN_ERR,
+                         "Filesystem with quota feature cannot be mounted RDWR "
+                         "without CONFIG_QUOTA");
+                return 0;
+        }
+#endif  /* CONFIG_QUOTA */
         return 1;
 }
 
@@ -3085,6 +3109,114 @@ static int set_journal_csum_feature_set(struct super_block *sb)
         return ret;
 }
 
+/*
+ * Note: calculating the overhead so we can be compatible with
+ * historical BSD practice is quite difficult in the face of
+ * clusters/bigalloc.  This is because multiple metadata blocks from
+ * different block group can end up in the same allocation cluster.
+ * Calculating the exact overhead in the face of clustered allocation
+ * requires either O(all block bitmaps) in memory or O(number of block
+ * groups**2) in time.  We will still calculate the superblock for
+ * older file systems --- and if we come across with a bigalloc file
+ * system with zero in s_overhead_clusters the estimate will be close to
+ * correct especially for very large cluster sizes --- but for newer
+ * file systems, it's better to calculate this figure once at mkfs
+ * time, and store it in the superblock.  If the superblock value is
+ * present (even for non-bigalloc file systems), we will use it.
+ */
+static int count_overhead(struct super_block *sb, ext4_group_t grp,
+                          char *buf)
+{
+        struct ext4_sb_info     *sbi = EXT4_SB(sb);
+        struct ext4_group_desc  *gdp;
+        ext4_fsblk_t            first_block, last_block, b;
+        ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
+        int                     s, j, count = 0;
+
+        first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
+                (grp * EXT4_BLOCKS_PER_GROUP(sb));
+        last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
+        for (i = 0; i < ngroups; i++) {
+                gdp = ext4_get_group_desc(sb, i, NULL);
+                b = ext4_block_bitmap(sb, gdp);
+                if (b >= first_block && b <= last_block) {
+                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+                        count++;
+                }
+                b = ext4_inode_bitmap(sb, gdp);
+                if (b >= first_block && b <= last_block) {
+                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+                        count++;
+                }
+                b = ext4_inode_table(sb, gdp);
+                if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
+                        for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
+                                int c = EXT4_B2C(sbi, b - first_block);
+                                ext4_set_bit(c, buf);
+                                count++;
+                        }
+                if (i != grp)
+                        continue;
+                s = 0;
+                if (ext4_bg_has_super(sb, grp)) {
+                        ext4_set_bit(s++, buf);
+                        count++;
+                }
+                for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
+                        ext4_set_bit(EXT4_B2C(sbi, s++), buf);
+                        count++;
+                }
+        }
+        if (!count)
+                return 0;
+        return EXT4_CLUSTERS_PER_GROUP(sb) -
+                ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
+}
+
+/*
+ * Compute the overhead and stash it in sbi->s_overhead
+ */
+int ext4_calculate_overhead(struct super_block *sb)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct ext4_super_block *es = sbi->s_es;
+        ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+        ext4_fsblk_t overhead = 0;
+        char *buf = (char *) get_zeroed_page(GFP_KERNEL);
+
+        memset(buf, 0, PAGE_SIZE);
+        if (!buf)
+                return -ENOMEM;
+
+        /*
+         * Compute the overhead (FS structures).  This is constant
+         * for a given filesystem unless the number of block groups
+         * changes so we cache the previous value until it does.
+         */
+
+        /*
+         * All of the blocks before first_data_block are overhead
+         */
+        overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
+
+        /*
+         * Add the overhead found in each block group
+         */
+        for (i = 0; i < ngroups; i++) {
+                int blks;
+
+                blks = count_overhead(sb, i, buf);
+                overhead += blks;
+                if (blks)
+                        memset(buf, 0, PAGE_SIZE);
+                cond_resched();
+        }
+        sbi->s_overhead = overhead;
+        smp_wmb();
+        free_page((unsigned long) buf);
+        return 0;
+}
+
 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 {
         char *orig_data = kstrdup(data, GFP_KERNEL);
@@ -3640,6 +3772,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 #ifdef CONFIG_QUOTA
         sb->s_qcop = &ext4_qctl_operations;
         sb->dq_op = &ext4_quota_operations;
+
+        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
+                /* Use qctl operations for hidden quota files. */
+                sb->s_qcop = &ext4_qctl_sysfile_operations;
+        }
 #endif
         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
 
@@ -3735,6 +3872,18 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 
 no_journal:
         /*
+         * Get the # of file system overhead blocks from the
+         * superblock if present.
+         */
+        if (es->s_overhead_clusters)
+                sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
+        else {
+                ret = ext4_calculate_overhead(sb);
+                if (ret)
+                        goto failed_mount_wq;
+        }
+
+        /*
          * The maximum number of concurrent works can be high and
          * concurrency isn't really necessary.  Limit it to 1.
          */
@@ -3840,6 +3989,16 @@ no_journal:
         } else
                 descr = "out journal";
 
+#ifdef CONFIG_QUOTA
+        /* Enable quota usage during mount. */
+        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
+            !(sb->s_flags & MS_RDONLY)) {
+                ret = ext4_enable_quotas(sb);
+                if (ret)
+                        goto failed_mount7;
+        }
+#endif  /* CONFIG_QUOTA */
+
         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
@@ -4203,7 +4362,6 @@ static int ext4_commit_super(struct super_block *sb, int sync)
         es->s_free_inodes_count =
                 cpu_to_le32(percpu_counter_sum_positive(
                                 &EXT4_SB(sb)->s_freeinodes_counter));
-        sb->s_dirt = 0;
         BUFFER_TRACE(sbh, "marking dirty");
         ext4_superblock_csum_set(sb, es);
         mark_buffer_dirty(sbh);
@@ -4310,13 +4468,6 @@ int ext4_force_commit(struct super_block *sb)
         return ret;
 }
 
-static void ext4_write_super(struct super_block *sb)
-{
-        lock_super(sb);
-        ext4_commit_super(sb, 1);
-        unlock_super(sb);
-}
-
 static int ext4_sync_fs(struct super_block *sb, int wait)
 {
         int ret = 0;
@@ -4567,16 +4718,26 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
         if (sbi->s_journal == NULL)
                 ext4_commit_super(sb, 1);
 
+        unlock_super(sb);
 #ifdef CONFIG_QUOTA
         /* Release old quota file names */
         for (i = 0; i < MAXQUOTAS; i++)
                 if (old_opts.s_qf_names[i] &&
                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
                         kfree(old_opts.s_qf_names[i]);
+        if (enable_quota) {
+                if (sb_any_quota_suspended(sb))
+                        dquot_resume(sb, -1);
+                else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                                        EXT4_FEATURE_RO_COMPAT_QUOTA)) {
+                        err = ext4_enable_quotas(sb);
+                        if (err) {
+                                lock_super(sb);
+                                goto restore_opts;
+                        }
+                }
+        }
 #endif
-        unlock_super(sb);
-        if (enable_quota)
-                dquot_resume(sb, -1);
 
         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
         kfree(orig_data);
@@ -4605,67 +4766,21 @@ restore_opts:
         return err;
 }
 
-/*
- * Note: calculating the overhead so we can be compatible with
- * historical BSD practice is quite difficult in the face of
- * clusters/bigalloc.  This is because multiple metadata blocks from
- * different block group can end up in the same allocation cluster.
- * Calculating the exact overhead in the face of clustered allocation
- * requires either O(all block bitmaps) in memory or O(number of block
- * groups**2) in time.  We will still calculate the superblock for
- * older file systems --- and if we come across with a bigalloc file
- * system with zero in s_overhead_clusters the estimate will be close to
- * correct especially for very large cluster sizes --- but for newer
- * file systems, it's better to calculate this figure once at mkfs
- * time, and store it in the superblock.  If the superblock value is
- * present (even for non-bigalloc file systems), we will use it.
- */
 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
         struct super_block *sb = dentry->d_sb;
         struct ext4_sb_info *sbi = EXT4_SB(sb);
         struct ext4_super_block *es = sbi->s_es;
-        struct ext4_group_desc *gdp;
+        ext4_fsblk_t overhead = 0;
         u64 fsid;
         s64 bfree;
 
-        if (test_opt(sb, MINIX_DF)) {
-                sbi->s_overhead_last = 0;
-        } else if (es->s_overhead_clusters) {
-                sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
-        } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
-                ext4_group_t i, ngroups = ext4_get_groups_count(sb);
-                ext4_fsblk_t overhead = 0;
-
-                /*
-                 * Compute the overhead (FS structures).  This is constant
-                 * for a given filesystem unless the number of block groups
-                 * changes so we cache the previous value until it does.
-                 */
-
-                /*
-                 * All of the blocks before first_data_block are
-                 * overhead
-                 */
-                overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
-
-                /*
-                 * Add the overhead found in each block group
-                 */
-                for (i = 0; i < ngroups; i++) {
-                        gdp = ext4_get_group_desc(sb, i, NULL);
-                        overhead += ext4_num_overhead_clusters(sb, i, gdp);
-                        cond_resched();
-                }
-                sbi->s_overhead_last = overhead;
-                smp_wmb();
-                sbi->s_blocks_last = ext4_blocks_count(es);
-        }
+        if (!test_opt(sb, MINIX_DF))
+                overhead = sbi->s_overhead;
 
         buf->f_type = EXT4_SUPER_MAGIC;
         buf->f_bsize = sb->s_blocksize;
-        buf->f_blocks = (ext4_blocks_count(es) -
-                         EXT4_C2B(sbi, sbi->s_overhead_last));
+        buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
         /* prevent underflow in case that few free space is available */
@@ -4835,6 +4950,74 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
         return dquot_quota_on(sb, type, format_id, path);
 }
 
+static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
+                             unsigned int flags)
+{
+        int err;
+        struct inode *qf_inode;
+        unsigned long qf_inums[MAXQUOTAS] = {
+                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
+                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
+        };
+
+        BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
+
+        if (!qf_inums[type])
+                return -EPERM;
+
+        qf_inode = ext4_iget(sb, qf_inums[type]);
+        if (IS_ERR(qf_inode)) {
+                ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
+                return PTR_ERR(qf_inode);
+        }
+
+        err = dquot_enable(qf_inode, type, format_id, flags);
+        iput(qf_inode);
+
+        return err;
+}
+
+/* Enable usage tracking for all quota types. */
+static int ext4_enable_quotas(struct super_block *sb)
+{
+        int type, err = 0;
+        unsigned long qf_inums[MAXQUOTAS] = {
+                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
+                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
+        };
+
+        sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
+        for (type = 0; type < MAXQUOTAS; type++) {
+                if (qf_inums[type]) {
+                        err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
+                                                DQUOT_USAGE_ENABLED);
+                        if (err) {
+                                ext4_warning(sb,
+                                        "Failed to enable quota (type=%d) "
+                                        "tracking. Please run e2fsck to fix.",
+                                        type);
+                                return err;
+                        }
+                }
+        }
+        return 0;
+}
+
+/*
+ * quota_on function that is used when QUOTA feature is set.
+ */
+static int ext4_quota_on_sysfile(struct super_block *sb, int type,
+                                 int format_id)
+{
+        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
+                return -EINVAL;
+
+        /*
+         * USAGE was enabled at mount time. Only need to enable LIMITS now.
+         */
+        return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
+}
+
 static int ext4_quota_off(struct super_block *sb, int type)
 {
         struct inode *inode = sb_dqopt(sb)->files[type];
@@ -4861,6 +5044,18 @@ out:
         return dquot_quota_off(sb, type);
 }
 
+/*
+ * quota_off function that is used when QUOTA feature is set.
+ */
+static int ext4_quota_off_sysfile(struct super_block *sb, int type)
+{
+        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
+                return -EINVAL;
+
+        /* Disable only the limits. */
+        return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
+}
+
 /* Read data from quotafile - avoid pagecache and such because we cannot afford
  * acquiring the locks... As quota files are never truncated and quota code
  * itself serializes the operations (and no one else should touch the files)