2 files changed, 165 insertions, 65 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 7f7dad787603..8b84fe28ccaf 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -365,26 +365,11 @@ group_add_out:
                         return -EOPNOTSUPP;
                 }
 
-                if (EXT4_HAS_INCOMPAT_FEATURE(sb,
-                               EXT4_FEATURE_INCOMPAT_META_BG)) {
-                        ext4_msg(sb, KERN_ERR,
-                                 "Online resizing not (yet) supported with meta_bg");
-                        return -EOPNOTSUPP;
-                }
-
                 if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
                                    sizeof(__u64))) {
                         return -EFAULT;
                 }
 
-                if (n_blocks_count > MAX_32_NUM &&
-                    !EXT4_HAS_INCOMPAT_FEATURE(sb,
-                                               EXT4_FEATURE_INCOMPAT_64BIT)) {
-                        ext4_msg(sb, KERN_ERR,
-                                 "File system only supports 32-bit block numbers");
-                        return -EOPNOTSUPP;
-                }
-
                 err = ext4_resize_begin(sb);
                 if (err)
                         return err;
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index f288933bf4c0..7adc08854588 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -45,6 +45,28 @@ void ext4_resize_end(struct super_block *sb)
         smp_mb__after_clear_bit();
 }
 
+static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb,
+                                             ext4_group_t group) {
+        return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) <<
+               EXT4_DESC_PER_BLOCK_BITS(sb);
+}
+
+static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb,
+                                             ext4_group_t group) {
+        group = ext4_meta_bg_first_group(sb, group);
+        return ext4_group_first_block_no(sb, group);
+}
+
+static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb,
+                                                ext4_group_t group) {
+        ext4_grpblk_t overhead;
+        overhead = ext4_bg_num_gdb(sb, group);
+        if (ext4_bg_has_super(sb, group))
+                overhead += 1 +
+                          le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
+        return overhead;
+}
+
 #define outside(b, first, last) ((b) < (first) || (b) >= (last))
 #define inside(b, first, last)  ((b) >= (first) && (b) < (last))
 
@@ -57,9 +79,7 @@ static int verify_group_input(struct super_block *sb,
         ext4_fsblk_t end = start + input->blocks_count;
         ext4_group_t group = input->group;
         ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
-        unsigned overhead = ext4_bg_has_super(sb, group) ?
-                (1 + ext4_bg_num_gdb(sb, group) +
-                 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
+        unsigned overhead = ext4_group_overhead_blocks(sb, group);
         ext4_fsblk_t metaend = start + overhead;
         struct buffer_head *bh = NULL;
         ext4_grpblk_t free_blocks_count, offset;
@@ -209,7 +229,6 @@ static int ext4_alloc_group_tables(struct super_block *sb,
                                 int flexbg_size)
 {
         struct ext4_new_group_data *group_data = flex_gd->groups;
-        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
         ext4_fsblk_t start_blk;
         ext4_fsblk_t last_blk;
         ext4_group_t src_group;
@@ -234,19 +253,19 @@ next_group:
         start_blk = ext4_group_first_block_no(sb, src_group);
         last_blk = start_blk + group_data[src_group - group].blocks_count;
 
-        overhead = ext4_bg_has_super(sb, src_group) ?
-                   (1 + ext4_bg_num_gdb(sb, src_group) +
-                    le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
+        overhead = ext4_group_overhead_blocks(sb, src_group);
 
         start_blk += overhead;
 
         /* We collect contiguous blocks as much as possible. */
         src_group++;
-        for (; src_group <= last_group; src_group++)
-                if (!ext4_bg_has_super(sb, src_group))
+        for (; src_group <= last_group; src_group++) {
+                overhead = ext4_group_overhead_blocks(sb, src_group);
+                if (overhead != 0)
                         last_blk += group_data[src_group - group].blocks_count;
                 else
                         break;
+        }
 
         /* Allocate block bitmaps */
         for (; bb_index < flex_gd->count; bb_index++) {
@@ -438,11 +457,13 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
         ext4_group_t group, count;
         struct buffer_head *bh = NULL;
         int reserved_gdb, i, j, err = 0, err2;
+        int meta_bg;
 
         BUG_ON(!flex_gd->count || !group_data ||
                group_data[0].group != sbi->s_groups_count);
 
         reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
+        meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
 
         /* This transaction may be extended/restarted along the way */
         handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
@@ -452,15 +473,25 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
         group = group_data[0].group;
         for (i = 0; i < flex_gd->count; i++, group++) {
                 unsigned long gdblocks;
+                ext4_grpblk_t overhead;
 
                 gdblocks = ext4_bg_num_gdb(sb, group);
                 start = ext4_group_first_block_no(sb, group);
 
-                if (!ext4_bg_has_super(sb, group))
+                if (meta_bg == 0 && !ext4_bg_has_super(sb, group))
                         goto handle_itb;
 
+                if (meta_bg == 1) {
+                        ext4_group_t first_group;
+                        first_group = ext4_meta_bg_first_group(sb, group);
+                        if (first_group != group + 1 &&
+                            first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1)
+                                goto handle_itb;
+                }
+
+                block = start + ext4_bg_has_super(sb, group);
                 /* Copy all of the GDT blocks into the backup in this group */
-                for (j = 0, block = start + 1; j < gdblocks; j++, block++) {
+                for (j = 0; j < gdblocks; j++, block++) {
                         struct buffer_head *gdb;
 
                         ext4_debug("update backup group %#04llx\n", block);
@@ -530,11 +561,11 @@ handle_bb:
                         err = PTR_ERR(bh);
                         goto out;
                 }
-                if (ext4_bg_has_super(sb, group)) {
+                overhead = ext4_group_overhead_blocks(sb, group);
+                if (overhead != 0) {
                         ext4_debug("mark backup superblock %#04llx (+0)\n",
                                    start);
-                        ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb +
-                                                     1);
+                        ext4_set_bits(bh->b_data, 0, overhead);
                 }
                 ext4_mark_bitmap_end(group_data[i].blocks_count,
                                      sb->s_blocksize * 8, bh->b_data);
@@ -831,6 +862,45 @@ exit_bh:
 }
 
 /*
+ * add_new_gdb_meta_bg is the sister of add_new_gdb.
+ */
+static int add_new_gdb_meta_bg(struct super_block *sb,
+                               handle_t *handle, ext4_group_t group) {
+        ext4_fsblk_t gdblock;
+        struct buffer_head *gdb_bh;
+        struct buffer_head **o_group_desc, **n_group_desc;
+        unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
+        int err;
+
+        gdblock = ext4_meta_bg_first_block_no(sb, group) +
+                   ext4_bg_has_super(sb, group);
+        gdb_bh = sb_bread(sb, gdblock);
+        if (!gdb_bh)
+                return -EIO;
+        n_group_desc = ext4_kvmalloc((gdb_num + 1) *
+                                     sizeof(struct buffer_head *),
+                                     GFP_NOFS);
+        if (!n_group_desc) {
+                err = -ENOMEM;
+                ext4_warning(sb, "not enough memory for %lu groups",
+                             gdb_num + 1);
+                return err;
+        }
+
+        o_group_desc = EXT4_SB(sb)->s_group_desc;
+        memcpy(n_group_desc, o_group_desc,
+               EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
+        n_group_desc[gdb_num] = gdb_bh;
+        EXT4_SB(sb)->s_group_desc = n_group_desc;
+        EXT4_SB(sb)->s_gdb_count++;
+        ext4_kvfree(o_group_desc);
+        err = ext4_journal_get_write_access(handle, gdb_bh);
+        if (unlikely(err))
+                brelse(gdb_bh);
+        return err;
+}
+
+/*
  * Called when we are adding a new group which has a backup copy of each of
  * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
  * We need to add these reserved backup GDT blocks to the resize inode, so
@@ -958,16 +1028,16 @@ exit_free:
  * do not copy the full number of backups at this time.  The resize
  * which changed s_groups_count will backup again.
  */
-static void update_backups(struct super_block *sb,
-                           int blk_off, char *data, int size)
+static void update_backups(struct super_block *sb, int blk_off, char *data,
+                           int size, int meta_bg)
 {
         struct ext4_sb_info *sbi = EXT4_SB(sb);
-        const ext4_group_t last = sbi->s_groups_count;
+        ext4_group_t last;
         const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
         unsigned three = 1;
         unsigned five = 5;
         unsigned seven = 7;
-        ext4_group_t group;
+        ext4_group_t group = 0;
         int rest = sb->s_blocksize - size;
         handle_t *handle;
         int err = 0, err2;
@@ -981,8 +1051,17 @@ static void update_backups(struct super_block *sb,
 
         ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
 
-        while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
+        if (meta_bg == 0) {
+                group = ext4_list_backups(sb, &three, &five, &seven);
+                last = sbi->s_groups_count;
+        } else {
+                group = ext4_meta_bg_first_group(sb, group) + 1;
+                last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2);
+        }
+
+        while (group < sbi->s_groups_count) {
                 struct buffer_head *bh;
+                ext4_fsblk_t backup_block;
 
                 /* Out of journal space, and can't get more - abort - so sad */
                 if (ext4_handle_valid(handle) &&
@@ -991,13 +1070,20 @@ static void update_backups(struct super_block *sb,
                     (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
                         break;
 
-                bh = sb_getblk(sb, group * bpg + blk_off);
+                if (meta_bg == 0)
+                        backup_block = group * bpg + blk_off;
+                else
+                        backup_block = (ext4_group_first_block_no(sb, group) +
+                                        ext4_bg_has_super(sb, group));
+
+                bh = sb_getblk(sb, backup_block);
                 if (!bh) {
                         err = -EIO;
                         break;
                 }
-                ext4_debug("update metadata backup %#04lx\n",
-                          (unsigned long)bh->b_blocknr);
+                ext4_debug("update metadata backup %llu(+%llu)\n",
+                           backup_block, backup_block -
+                           ext4_group_first_block_no(sb, group));
                 if ((err = ext4_journal_get_write_access(handle, bh)))
                         break;
                 lock_buffer(bh);
@@ -1010,6 +1096,13 @@ static void update_backups(struct super_block *sb,
                 if (unlikely(err))
                         ext4_std_error(sb, err);
                 brelse(bh);
+
+                if (meta_bg == 0)
+                        group = ext4_list_backups(sb, &three, &five, &seven);
+                else if (group == last)
+                        break;
+                else
+                        group = last;
         }
         if ((err2 = ext4_journal_stop(handle)) && !err)
                 err = err2;
@@ -1052,7 +1145,9 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
         struct ext4_super_block *es = sbi->s_es;
         struct buffer_head *gdb_bh;
         int i, gdb_off, gdb_num, err = 0;
+        int meta_bg;
 
+        meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
         for (i = 0; i < count; i++, group++) {
                 int reserved_gdb = ext4_bg_has_super(sb, group) ?
                         le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
@@ -1072,8 +1167,11 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
 
                         if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
                                 err = reserve_backup_gdb(handle, resize_inode, group);
-                } else
+                } else if (meta_bg != 0) {
+                        err = add_new_gdb_meta_bg(sb, handle, group);
+                } else {
                         err = add_new_gdb(handle, resize_inode, group);
+                }
                 if (err)
                         break;
         }
@@ -1225,7 +1323,7 @@ static void ext4_update_super(struct super_block *sb,
         }
 
         reserved_blocks = ext4_r_blocks_count(es) * 100;
-        do_div(reserved_blocks, ext4_blocks_count(es));
+        reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es));
         reserved_blocks *= blocks_count;
         do_div(reserved_blocks, 100);
 
@@ -1236,6 +1334,7 @@ static void ext4_update_super(struct super_block *sb,
         le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
                      flex_gd->count);
 
+        ext4_debug("free blocks count %llu", ext4_free_blocks_count(es));
         /*
          * We need to protect s_groups_count against other CPUs seeing
          * inconsistent state in the superblock.
@@ -1270,6 +1369,8 @@ static void ext4_update_super(struct super_block *sb,
         percpu_counter_add(&sbi->s_freeinodes_counter,
                            EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
 
+        ext4_debug("free blocks count %llu",
+                   percpu_counter_read(&sbi->s_freeclusters_counter));
         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
                                       EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
             sbi->s_log_groups_per_flex) {
@@ -1361,15 +1462,17 @@ exit_journal:
                 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
                 int gdb_num_end = ((group + flex_gd->count - 1) /
                                    EXT4_DESC_PER_BLOCK(sb));
+                int meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb,
+                                EXT4_FEATURE_INCOMPAT_META_BG);
 
                 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
-                               sizeof(struct ext4_super_block));
+                               sizeof(struct ext4_super_block), 0);
                 for (; gdb_num <= gdb_num_end; gdb_num++) {
                         struct buffer_head *gdb_bh;
 
                         gdb_bh = sbi->s_group_desc[gdb_num];
                         update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
-                                       gdb_bh->b_size);
+                                       gdb_bh->b_size, meta_bg);
                 }
         }
 exit:
@@ -1413,9 +1516,7 @@ static int ext4_setup_next_flex_gd(struct super_block *sb,
 
                 group_data[i].group = group + i;
                 group_data[i].blocks_count = blocks_per_group;
-                overhead = ext4_bg_has_super(sb, group + i) ?
-                           (1 + ext4_bg_num_gdb(sb, group + i) +
-                            le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
+                overhead = ext4_group_overhead_blocks(sb, group + i);
                 group_data[i].free_blocks_count = blocks_per_group - overhead;
                 if (ext4_has_group_desc_csum(sb))
                         flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
@@ -1563,11 +1664,13 @@ errout:
                 err = err2;
 
         if (!err) {
+                ext4_fsblk_t first_block;
+                first_block = ext4_group_first_block_no(sb, 0);
                 if (test_opt(sb, DEBUG))
                         printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
                                "blocks\n", ext4_blocks_count(es));
-                update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
-                               sizeof(struct ext4_super_block));
+                update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr - first_block,
+                               (char *)es, sizeof(struct ext4_super_block), 0);
         }
         return err;
 }
@@ -1662,15 +1765,16 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
         struct ext4_sb_info *sbi = EXT4_SB(sb);
         struct ext4_super_block *es = sbi->s_es;
         struct buffer_head *bh;
-        struct inode *resize_inode;
-        ext4_fsblk_t o_blocks_count;
-        ext4_group_t o_group;
-        ext4_group_t n_group;
-        ext4_grpblk_t offset, add;
+        struct inode *resize_inode = NULL;
+        ext4_grpblk_t add, offset;
         unsigned long n_desc_blocks;
         unsigned long o_desc_blocks;
         unsigned long desc_blocks;
+        ext4_group_t o_group;
+        ext4_group_t n_group;
+        ext4_fsblk_t o_blocks_count;
         int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
+        int meta_bg;
 
         o_blocks_count = ext4_blocks_count(es);
 
@@ -1692,22 +1796,33 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
         ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
 
         n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) /
-                        EXT4_DESC_PER_BLOCK(sb);
+                         EXT4_DESC_PER_BLOCK(sb);
         o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
-                        EXT4_DESC_PER_BLOCK(sb);
+                         EXT4_DESC_PER_BLOCK(sb);
         desc_blocks = n_desc_blocks - o_desc_blocks;
 
-        if (desc_blocks &&
-            (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) ||
-             le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) {
-                ext4_warning(sb, "No reserved GDT blocks, can't resize");
-                return -EPERM;
-        }
+        meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
 
-        resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
-        if (IS_ERR(resize_inode)) {
-                ext4_warning(sb, "Error opening resize inode");
-                return PTR_ERR(resize_inode);
+        if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE)) {
+                if (meta_bg) {
+                        ext4_error(sb, "resize_inode and meta_bg enabled "
+                                   "simultaneously");
+                        return -EINVAL;
+                }
+                if (le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks) {
+                        ext4_warning(sb,
+                                     "No reserved GDT blocks, can't resize");
+                        return -EPERM;
+                }
+                resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
+                if (IS_ERR(resize_inode)) {
+                        ext4_warning(sb, "Error opening resize inode");
+                        return PTR_ERR(resize_inode);
+                }
+        } else if (!meta_bg) {
+                ext4_warning(sb, "File system features do not permit "
+                             "online resize");
+                return -EPERM;
         }
 
         /* See if the device is actually as big as what was requested */
@@ -1761,8 +1876,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
 out:
         if (flex_gd)
                 free_flex_gd(flex_gd);
-
-        iput(resize_inode);
+        if (resize_inode != NULL)
+                iput(resize_inode);
         if (test_opt(sb, DEBUG))
                 ext4_msg(sb, KERN_DEBUG, "resized filesystem from %llu "
                        "upto %llu blocks", o_blocks_count, n_blocks_count);