nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 343 insertions, 89 deletions

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 41f6ef68e2e1..7a75e1086961 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;
@@ -200,13 +220,15 @@ static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
  * be a partial of a flex group.
  *
  * @sb: super block of fs to which the groups belongs
+ *
+ * Returns 0 on a successful allocation of the metadata blocks in the
+ * block group.
  */
-static void ext4_alloc_group_tables(struct super_block *sb,
+static int ext4_alloc_group_tables(struct super_block *sb,
 				struct ext4_new_flex_group_data *flex_gd,
 				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;
@@ -226,23 +248,24 @@ static void ext4_alloc_group_tables(struct super_block *sb,
 	       (last_group & ~(flexbg_size - 1))));
 next_group:
 	group = group_data[0].group;
+	if (src_group >= group_data[0].group + flex_gd->count)
+		return -ENOSPC;
 	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;
 
-	BUG_ON(src_group >= group_data[0].group + flex_gd->count);
 	/* 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++) {
@@ -300,6 +323,7 @@ next_group:
 			       group_data[i].free_blocks_count);
 		}
 	}
+	return 0;
 }
 
 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
@@ -433,11 +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);
@@ -447,12 +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 (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);
@@ -493,6 +532,7 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
 				goto out;
 		}
 
+handle_itb:
 		/* Initialize group tables of the grop @group */
 		if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
 			goto handle_bb;
@@ -521,11 +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);
@@ -822,6 +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
@@ -949,16 +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;
@@ -970,10 +1049,17 @@ static void update_backups(struct super_block *sb,
 		goto exit_err;
 	}
 
-	ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
+	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 = ext4_list_backups(sb, &three, &five, &seven)) < last) {
+	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) &&
@@ -982,13 +1068,20 @@ 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);
@@ -1001,6 +1094,13 @@ 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;
@@ -1043,7 +1143,9 @@ 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;
@@ -1063,8 +1165,11 @@ 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;
 	}
@@ -1076,17 +1181,12 @@ static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
 	struct buffer_head *bh = sb_getblk(sb, block);
 	if (!bh)
 		return NULL;
-
-	if (bitmap_uptodate(bh))
-		return bh;
-
-	lock_buffer(bh);
-	if (bh_submit_read(bh) < 0) {
-		unlock_buffer(bh);
-		brelse(bh);
-		return NULL;
+	if (!bh_uptodate_or_lock(bh)) {
+		if (bh_submit_read(bh) < 0) {
+			brelse(bh);
+			return NULL;
+		}
 	}
-	unlock_buffer(bh);
 
 	return bh;
 }
@@ -1161,6 +1261,9 @@ static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
 		ext4_free_group_clusters_set(sb, gdp,
 					     EXT4_B2C(sbi, group_data->free_blocks_count));
 		ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
+		if (ext4_has_group_desc_csum(sb))
+			ext4_itable_unused_set(sb, gdp,
+					       EXT4_INODES_PER_GROUP(sb));
 		gdp->bg_flags = cpu_to_le16(*bg_flags);
 		ext4_group_desc_csum_set(sb, group, gdp);
 
@@ -1216,7 +1319,7 @@ 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);
 
@@ -1227,6 +1330,7 @@ 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.
@@ -1261,6 +1365,8 @@ 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) {
@@ -1349,16 +1455,24 @@ exit_journal:
 		err = err2;
 
 	if (!err) {
-		int i;
+		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);
+		sector_t old_gdb = 0;
+
 		update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
-			       sizeof(struct ext4_super_block));
-		for (i = 0; i < flex_gd->count; i++, group++) {
+			       sizeof(struct ext4_super_block), 0);
+		for (; gdb_num <= gdb_num_end; gdb_num++) {
 			struct buffer_head *gdb_bh;
-			int gdb_num;
-			gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb);
+
 			gdb_bh = sbi->s_group_desc[gdb_num];
+			if (old_gdb == gdb_bh->b_blocknr)
+				continue;
 			update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
-				       gdb_bh->b_size);
+				       gdb_bh->b_size, meta_bg);
+			old_gdb = gdb_bh->b_blocknr;
 		}
 	}
 exit:
@@ -1402,9 +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 |
@@ -1492,6 +1604,14 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 	if (err)
 		goto out;
 
+	err = ext4_alloc_flex_bg_array(sb, input->group + 1);
+	if (err)
+		return err;
+
+	err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
+	if (err)
+		goto out;
+
 	flex_gd.count = 1;
 	flex_gd.groups = input;
 	flex_gd.bg_flags = &bg_flags;
@@ -1544,11 +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;
 }
@@ -1631,6 +1753,94 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
 	return err;
 } /* ext4_group_extend */
 
+
+static int num_desc_blocks(struct super_block *sb, ext4_group_t groups)
+{
+	return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb);
+}
+
+/*
+ * Release the resize inode and drop the resize_inode feature if there
+ * are no more reserved gdt blocks, and then convert the file system
+ * to enable meta_bg
+ */
+static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
+{
+	handle_t *handle;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	ext4_fsblk_t nr;
+	int i, ret, err = 0;
+	int credits = 1;
+
+	ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");
+	if (inode) {
+		if (es->s_reserved_gdt_blocks) {
+			ext4_error(sb, "Unexpected non-zero "
+				   "s_reserved_gdt_blocks");
+			return -EPERM;
+		}
+
+		/* Do a quick sanity check of the resize inode */
+		if (inode->i_blocks != 1 << (inode->i_blkbits - 9))
+			goto invalid_resize_inode;
+		for (i = 0; i < EXT4_N_BLOCKS; i++) {
+			if (i == EXT4_DIND_BLOCK) {
+				if (ei->i_data[i])
+					continue;
+				else
+					goto invalid_resize_inode;
+			}
+			if (ei->i_data[i])
+				goto invalid_resize_inode;
+		}
+		credits += 3;	/* block bitmap, bg descriptor, resize inode */
+	}
+
+	handle = ext4_journal_start_sb(sb, credits);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+	if (err)
+		goto errout;
+
+	EXT4_CLEAR_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE);
+	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG);
+	sbi->s_es->s_first_meta_bg =
+		cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count));
+
+	err = ext4_handle_dirty_super(handle, sb);
+	if (err) {
+		ext4_std_error(sb, err);
+		goto errout;
+	}
+
+	if (inode) {
+		nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]);
+		ext4_free_blocks(handle, inode, NULL, nr, 1,
+				 EXT4_FREE_BLOCKS_METADATA |
+				 EXT4_FREE_BLOCKS_FORGET);
+		ei->i_data[EXT4_DIND_BLOCK] = 0;
+		inode->i_blocks = 0;
+
+		err = ext4_mark_inode_dirty(handle, inode);
+		if (err)
+			ext4_std_error(sb, err);
+	}
+
+errout:
+	ret = ext4_journal_stop(handle);
+	if (!err)
+		err = ret;
+	return ret;
+
+invalid_resize_inode:
+	ext4_error(sb, "corrupted/inconsistent resize inode");
+	return -EINVAL;
+}
+
 /*
  * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
  *
@@ -1643,21 +1853,31 @@ 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;
-	int err = 0, flexbg_size = 1;
+	ext4_group_t o_group;
+	ext4_group_t n_group;
+	ext4_fsblk_t o_blocks_count;
+	ext4_fsblk_t n_blocks_count_retry = 0;
+	unsigned long last_update_time = 0;
+	int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
+	int meta_bg;
 
+	/* See if the device is actually as big as what was requested */
+	bh = sb_bread(sb, n_blocks_count - 1);
+	if (!bh) {
+		ext4_warning(sb, "can't read last block, resize aborted");
+		return -ENOSPC;
+	}
+	brelse(bh);
+
+retry:
 	o_blocks_count = ext4_blocks_count(es);
 
-	if (test_opt(sb, DEBUG))
-		ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu "
-		       "to %llu blocks", o_blocks_count, n_blocks_count);
+	ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
+		 "to %llu blocks", o_blocks_count, n_blocks_count);
 
 	if (n_blocks_count < o_blocks_count) {
 		/* On-line shrinking not supported */
@@ -1672,32 +1892,49 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
 	ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
 	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);
-	o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
-			EXT4_DESC_PER_BLOCK(sb);
-	desc_blocks = n_desc_blocks - o_desc_blocks;
+	n_desc_blocks = num_desc_blocks(sb, n_group + 1);
+	o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count);
 
-	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 (n_desc_blocks > o_desc_blocks +
+		    le16_to_cpu(es->s_reserved_gdt_blocks)) {
+			n_blocks_count_retry = n_blocks_count;
+			n_desc_blocks = o_desc_blocks +
+				le16_to_cpu(es->s_reserved_gdt_blocks);
+			n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb);
+			n_blocks_count = n_group * EXT4_BLOCKS_PER_GROUP(sb);
+			n_group--; /* set to last group number */
+		}
+
+		if (!resize_inode)
+			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);
+		}
 	}
 
-	/* See if the device is actually as big as what was requested */
-	bh = sb_bread(sb, n_blocks_count - 1);
-	if (!bh) {
-		ext4_warning(sb, "can't read last block, resize aborted");
-		return -ENOSPC;
+	if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {
+		err = ext4_convert_meta_bg(sb, resize_inode);
+		if (err)
+			goto out;
+		if (resize_inode) {
+			iput(resize_inode);
+			resize_inode = NULL;
+		}
+		if (n_blocks_count_retry) {
+			n_blocks_count = n_blocks_count_retry;
+			n_blocks_count_retry = 0;
+			goto retry;
+		}
 	}
-	brelse(bh);
 
 	/* extend the last group */
 	if (n_group == o_group)
@@ -1710,12 +1947,15 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
 			goto out;
 	}
 
-	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
-	    es->s_log_groups_per_flex)
-		flexbg_size = 1 << es->s_log_groups_per_flex;
+	if (ext4_blocks_count(es) == n_blocks_count)
+		goto out;
 
-	o_blocks_count = ext4_blocks_count(es);
-	if (o_blocks_count == n_blocks_count)
+	err = ext4_alloc_flex_bg_array(sb, n_group + 1);
+	if (err)
+		return err;
+
+	err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
+	if (err)
 		goto out;
 
 	flex_gd = alloc_flex_gd(flexbg_size);
@@ -1729,19 +1969,33 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
 	 */
 	while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
 					      flexbg_size)) {
-		ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
+		if (jiffies - last_update_time > HZ * 10) {
+			if (last_update_time)
+				ext4_msg(sb, KERN_INFO,
+					 "resized to %llu blocks",
+					 ext4_blocks_count(es));
+			last_update_time = jiffies;
+		}
+		if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
+			break;
 		err = ext4_flex_group_add(sb, resize_inode, flex_gd);
 		if (unlikely(err))
 			break;
 	}
 
+	if (!err && n_blocks_count_retry) {
+		n_blocks_count = n_blocks_count_retry;
+		n_blocks_count_retry = 0;
+		free_flex_gd(flex_gd);
+		flex_gd = NULL;
+		goto retry;
+	}
+
 out:
 	if (flex_gd)
 		free_flex_gd(flex_gd);
-
-	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);
+	if (resize_inode != NULL)
+		iput(resize_inode);
+	ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count);
 	return err;
 }