Initial import

1 files changed, 1350 insertions, 0 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
new file mode 100644
index 000000000..1eaa6cb96
--- /dev/null
+++ b/fs/ext4/ialloc.c
@@ -0,0 +1,1350 @@
+/*
+ *  linux/fs/ext4/ialloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  BSD ufs-inspired inode and directory allocation by
+ *  Stephen Tweedie (sct@redhat.com), 1993
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+#include <linux/blkdev.h>
+#include <asm/byteorder.h>
+
+#include "ext4.h"
+#include "ext4_jbd2.h"
+#include "xattr.h"
+#include "acl.h"
+
+#include <trace/events/ext4.h>
+
+/*
+ * ialloc.c contains the inodes allocation and deallocation routines
+ */
+
+/*
+ * The free inodes are managed by bitmaps.  A file system contains several
+ * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block.  Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block.
+ */
+
+/*
+ * To avoid calling the atomic setbit hundreds or thousands of times, we only
+ * need to use it within a single byte (to ensure we get endianness right).
+ * We can use memset for the rest of the bitmap as there are no other users.
+ */
+void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
+{
+	int i;
+
+	if (start_bit >= end_bit)
+		return;
+
+	ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
+	for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
+		ext4_set_bit(i, bitmap);
+	if (i < end_bit)
+		memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
+}
+
+/* Initializes an uninitialized inode bitmap */
+static unsigned ext4_init_inode_bitmap(struct super_block *sb,
+				       struct buffer_head *bh,
+				       ext4_group_t block_group,
+				       struct ext4_group_desc *gdp)
+{
+	struct ext4_group_info *grp;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	J_ASSERT_BH(bh, buffer_locked(bh));
+
+	/* If checksum is bad mark all blocks and inodes use to prevent
+	 * allocation, essentially implementing a per-group read-only flag. */
+	if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
+		ext4_error(sb, "Checksum bad for group %u", block_group);
+		grp = ext4_get_group_info(sb, block_group);
+		if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
+			percpu_counter_sub(&sbi->s_freeclusters_counter,
+					   grp->bb_free);
+		set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
+		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+			int count;
+			count = ext4_free_inodes_count(sb, gdp);
+			percpu_counter_sub(&sbi->s_freeinodes_counter,
+					   count);
+		}
+		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
+		return 0;
+	}
+
+	memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
+	ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
+			bh->b_data);
+	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
+				   EXT4_INODES_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, gdp);
+
+	return EXT4_INODES_PER_GROUP(sb);
+}
+
+void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
+{
+	if (uptodate) {
+		set_buffer_uptodate(bh);
+		set_bitmap_uptodate(bh);
+	}
+	unlock_buffer(bh);
+	put_bh(bh);
+}
+
+/*
+ * Read the inode allocation bitmap for a given block_group, reading
+ * into the specified slot in the superblock's bitmap cache.
+ *
+ * Return buffer_head of bitmap on success or NULL.
+ */
+static struct buffer_head *
+ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
+{
+	struct ext4_group_desc *desc;
+	struct buffer_head *bh = NULL;
+	ext4_fsblk_t bitmap_blk;
+	struct ext4_group_info *grp;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	desc = ext4_get_group_desc(sb, block_group, NULL);
+	if (!desc)
+		return NULL;
+
+	bitmap_blk = ext4_inode_bitmap(sb, desc);
+	bh = sb_getblk(sb, bitmap_blk);
+	if (unlikely(!bh)) {
+		ext4_error(sb, "Cannot read inode bitmap - "
+			    "block_group = %u, inode_bitmap = %llu",
+			    block_group, bitmap_blk);
+		return NULL;
+	}
+	if (bitmap_uptodate(bh))
+		goto verify;
+
+	lock_buffer(bh);
+	if (bitmap_uptodate(bh)) {
+		unlock_buffer(bh);
+		goto verify;
+	}
+
+	ext4_lock_group(sb, block_group);
+	if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
+		ext4_init_inode_bitmap(sb, bh, block_group, desc);
+		set_bitmap_uptodate(bh);
+		set_buffer_uptodate(bh);
+		set_buffer_verified(bh);
+		ext4_unlock_group(sb, block_group);
+		unlock_buffer(bh);
+		return bh;
+	}
+	ext4_unlock_group(sb, block_group);
+
+	if (buffer_uptodate(bh)) {
+		/*
+		 * if not uninit if bh is uptodate,
+		 * bitmap is also uptodate
+		 */
+		set_bitmap_uptodate(bh);
+		unlock_buffer(bh);
+		goto verify;
+	}
+	/*
+	 * submit the buffer_head for reading
+	 */
+	trace_ext4_load_inode_bitmap(sb, block_group);
+	bh->b_end_io = ext4_end_bitmap_read;
+	get_bh(bh);
+	submit_bh(READ | REQ_META | REQ_PRIO, bh);
+	wait_on_buffer(bh);
+	if (!buffer_uptodate(bh)) {
+		put_bh(bh);
+		ext4_error(sb, "Cannot read inode bitmap - "
+			   "block_group = %u, inode_bitmap = %llu",
+			   block_group, bitmap_blk);
+		return NULL;
+	}
+
+verify:
+	ext4_lock_group(sb, block_group);
+	if (!buffer_verified(bh) &&
+	    !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
+					   EXT4_INODES_PER_GROUP(sb) / 8)) {
+		ext4_unlock_group(sb, block_group);
+		put_bh(bh);
+		ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
+			   "inode_bitmap = %llu", block_group, bitmap_blk);
+		grp = ext4_get_group_info(sb, block_group);
+		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+			int count;
+			count = ext4_free_inodes_count(sb, desc);
+			percpu_counter_sub(&sbi->s_freeinodes_counter,
+					   count);
+		}
+		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
+		return NULL;
+	}
+	ext4_unlock_group(sb, block_group);
+	set_buffer_verified(bh);
+	return bh;
+}
+
+/*
+ * NOTE! When we get the inode, we're the only people
+ * that have access to it, and as such there are no
+ * race conditions we have to worry about. The inode
+ * is not on the hash-lists, and it cannot be reached
+ * through the filesystem because the directory entry
+ * has been deleted earlier.
+ *
+ * HOWEVER: we must make sure that we get no aliases,
+ * which means that we have to call "clear_inode()"
+ * _before_ we mark the inode not in use in the inode
+ * bitmaps. Otherwise a newly created file might use
+ * the same inode number (not actually the same pointer
+ * though), and then we'd have two inodes sharing the
+ * same inode number and space on the harddisk.
+ */
+void ext4_free_inode(handle_t *handle, struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	int is_directory;
+	unsigned long ino;
+	struct buffer_head *bitmap_bh = NULL;
+	struct buffer_head *bh2;
+	ext4_group_t block_group;
+	unsigned long bit;
+	struct ext4_group_desc *gdp;
+	struct ext4_super_block *es;
+	struct ext4_sb_info *sbi;
+	int fatal = 0, err, count, cleared;
+	struct ext4_group_info *grp;
+
+	if (!sb) {
+		printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
+		       "nonexistent device\n", __func__, __LINE__);
+		return;
+	}
+	if (atomic_read(&inode->i_count) > 1) {
+		ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
+			 __func__, __LINE__, inode->i_ino,
+			 atomic_read(&inode->i_count));
+		return;
+	}
+	if (inode->i_nlink) {
+		ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
+			 __func__, __LINE__, inode->i_ino, inode->i_nlink);
+		return;
+	}
+	sbi = EXT4_SB(sb);
+
+	ino = inode->i_ino;
+	ext4_debug("freeing inode %lu\n", ino);
+	trace_ext4_free_inode(inode);
+
+	/*
+	 * Note: we must free any quota before locking the superblock,
+	 * as writing the quota to disk may need the lock as well.
+	 */
+	dquot_initialize(inode);
+	ext4_xattr_delete_inode(handle, inode);
+	dquot_free_inode(inode);
+	dquot_drop(inode);
+
+	is_directory = S_ISDIR(inode->i_mode);
+
+	/* Do this BEFORE marking the inode not in use or returning an error */
+	ext4_clear_inode(inode);
+
+	es = EXT4_SB(sb)->s_es;
+	if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+		ext4_error(sb, "reserved or nonexistent inode %lu", ino);
+		goto error_return;
+	}
+	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
+	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
+	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
+	/* Don't bother if the inode bitmap is corrupt. */
+	grp = ext4_get_group_info(sb, block_group);
+	if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) || !bitmap_bh)
+		goto error_return;
+
+	BUFFER_TRACE(bitmap_bh, "get_write_access");
+	fatal = ext4_journal_get_write_access(handle, bitmap_bh);
+	if (fatal)
+		goto error_return;
+
+	fatal = -ESRCH;
+	gdp = ext4_get_group_desc(sb, block_group, &bh2);
+	if (gdp) {
+		BUFFER_TRACE(bh2, "get_write_access");
+		fatal = ext4_journal_get_write_access(handle, bh2);
+	}
+	ext4_lock_group(sb, block_group);
+	cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
+	if (fatal || !cleared) {
+		ext4_unlock_group(sb, block_group);
+		goto out;
+	}
+
+	count = ext4_free_inodes_count(sb, gdp) + 1;
+	ext4_free_inodes_set(sb, gdp, count);
+	if (is_directory) {
+		count = ext4_used_dirs_count(sb, gdp) - 1;
+		ext4_used_dirs_set(sb, gdp, count);
+		percpu_counter_dec(&sbi->s_dirs_counter);
+	}
+	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
+				   EXT4_INODES_PER_GROUP(sb) / 8);
+	ext4_group_desc_csum_set(sb, block_group, gdp);
+	ext4_unlock_group(sb, block_group);
+
+	percpu_counter_inc(&sbi->s_freeinodes_counter);
+	if (sbi->s_log_groups_per_flex) {
+		ext4_group_t f = ext4_flex_group(sbi, block_group);
+
+		atomic_inc(&sbi->s_flex_groups[f].free_inodes);
+		if (is_directory)
+			atomic_dec(&sbi->s_flex_groups[f].used_dirs);
+	}
+	BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
+	fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
+out:
+	if (cleared) {
+		BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
+		err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
+		if (!fatal)
+			fatal = err;
+	} else {
+		ext4_error(sb, "bit already cleared for inode %lu", ino);
+		if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+			int count;
+			count = ext4_free_inodes_count(sb, gdp);
+			percpu_counter_sub(&sbi->s_freeinodes_counter,
+					   count);
+		}
+		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
+	}
+
+error_return:
+	brelse(bitmap_bh);
+	ext4_std_error(sb, fatal);
+}
+
+struct orlov_stats {
+	__u64 free_clusters;
+	__u32 free_inodes;
+	__u32 used_dirs;
+};
+
+/*
+ * Helper function for Orlov's allocator; returns critical information
+ * for a particular block group or flex_bg.  If flex_size is 1, then g
+ * is a block group number; otherwise it is flex_bg number.
+ */
+static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
+			    int flex_size, struct orlov_stats *stats)
+{
+	struct ext4_group_desc *desc;
+	struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
+
+	if (flex_size > 1) {
+		stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
+		stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
+		stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
+		return;
+	}
+
+	desc = ext4_get_group_desc(sb, g, NULL);
+	if (desc) {
+		stats->free_inodes = ext4_free_inodes_count(sb, desc);
+		stats->free_clusters = ext4_free_group_clusters(sb, desc);
+		stats->used_dirs = ext4_used_dirs_count(sb, desc);
+	} else {
+		stats->free_inodes = 0;
+		stats->free_clusters = 0;
+		stats->used_dirs = 0;
+	}
+}
+
+/*
+ * Orlov's allocator for directories.
+ *
+ * We always try to spread first-level directories.
+ *
+ * If there are blockgroups with both free inodes and free blocks counts
+ * not worse than average we return one with smallest directory count.
+ * Otherwise we simply return a random group.
+ *
+ * For the rest rules look so:
+ *
+ * It's OK to put directory into a group unless
+ * it has too many directories already (max_dirs) or
+ * it has too few free inodes left (min_inodes) or
+ * it has too few free blocks left (min_blocks) or
+ * Parent's group is preferred, if it doesn't satisfy these
+ * conditions we search cyclically through the rest. If none
+ * of the groups look good we just look for a group with more
+ * free inodes than average (starting at parent's group).
+ */
+
+static int find_group_orlov(struct super_block *sb, struct inode *parent,
+			    ext4_group_t *group, umode_t mode,
+			    const struct qstr *qstr)
+{
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	ext4_group_t real_ngroups = ext4_get_groups_count(sb);
+	int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
+	unsigned int freei, avefreei, grp_free;
+	ext4_fsblk_t freeb, avefreec;
+	unsigned int ndirs;
+	int max_dirs, min_inodes;
+	ext4_grpblk_t min_clusters;
+	ext4_group_t i, grp, g, ngroups;
+	struct ext4_group_desc *desc;
+	struct orlov_stats stats;
+	int flex_size = ext4_flex_bg_size(sbi);
+	struct dx_hash_info hinfo;
+
+	ngroups = real_ngroups;
+	if (flex_size > 1) {
+		ngroups = (real_ngroups + flex_size - 1) >>
+			sbi->s_log_groups_per_flex;
+		parent_group >>= sbi->s_log_groups_per_flex;
+	}
+
+	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
+	avefreei = freei / ngroups;
+	freeb = EXT4_C2B(sbi,
+		percpu_counter_read_positive(&sbi->s_freeclusters_counter));
+	avefreec = freeb;
+	do_div(avefreec, ngroups);
+	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
+
+	if (S_ISDIR(mode) &&
+	    ((parent == d_inode(sb->s_root)) ||
+	     (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
+		int best_ndir = inodes_per_group;
+		int ret = -1;
+
+		if (qstr) {
+			hinfo.hash_version = DX_HASH_HALF_MD4;
+			hinfo.seed = sbi->s_hash_seed;
+			ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
+			grp = hinfo.hash;
+		} else
+			grp = prandom_u32();
+		parent_group = (unsigned)grp % ngroups;
+		for (i = 0; i < ngroups; i++) {
+			g = (parent_group + i) % ngroups;
+			get_orlov_stats(sb, g, flex_size, &stats);
+			if (!stats.free_inodes)
+				continue;
+			if (stats.used_dirs >= best_ndir)
+				continue;
+			if (stats.free_inodes < avefreei)
+				continue;
+			if (stats.free_clusters < avefreec)
+				continue;
+			grp = g;
+			ret = 0;
+			best_ndir = stats.used_dirs;
+		}
+		if (ret)
+			goto fallback;
+	found_flex_bg:
+		if (flex_size == 1) {
+			*group = grp;
+			return 0;
+		}
+
+		/*
+		 * We pack inodes at the beginning of the flexgroup's
+		 * inode tables.  Block allocation decisions will do
+		 * something similar, although regular files will
+		 * start at 2nd block group of the flexgroup.  See
+		 * ext4_ext_find_goal() and ext4_find_near().
+		 */
+		grp *= flex_size;
+		for (i = 0; i < flex_size; i++) {
+			if (grp+i >= real_ngroups)
+				break;
+			desc = ext4_get_group_desc(sb, grp+i, NULL);
+			if (desc && ext4_free_inodes_count(sb, desc)) {
+				*group = grp+i;
+				return 0;
+			}
+		}
+		goto fallback;
+	}
+
+	max_dirs = ndirs / ngroups + inodes_per_group / 16;
+	min_inodes = avefreei - inodes_per_group*flex_size / 4;
+	if (min_inodes < 1)
+		min_inodes = 1;
+	min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
+
+	/*
+	 * Start looking in the flex group where we last allocated an
+	 * inode for this parent directory
+	 */
+	if (EXT4_I(parent)->i_last_alloc_group != ~0) {
+		parent_group = EXT4_I(parent)->i_last_alloc_group;
+		if (flex_size > 1)
+			parent_group >>= sbi->s_log_groups_per_flex;
+	}
+
+	for (i = 0; i < ngroups; i++) {
+		grp = (parent_group + i) % ngroups;
+		get_orlov_stats(sb, grp, flex_size, &stats);
+		if (stats.used_dirs >= max_dirs)
+			continue;
+		if (stats.free_inodes < min_inodes)
+			continue;
+		if (stats.free_clusters < min_clusters)
+			continue;
+		goto found_flex_bg;
+	}
+
+fallback:
+	ngroups = real_ngroups;
+	avefreei = freei / ngroups;
+fallback_retry:
+	parent_group = EXT4_I(parent)->i_block_group;
+	for (i = 0; i < ngroups; i++) {
+		grp = (parent_group + i) % ngroups;
+		desc = ext4_get_group_desc(sb, grp, NULL);
+		if (desc) {
+			grp_free = ext4_free_inodes_count(sb, desc);
+			if (grp_free && grp_free >= avefreei) {
+				*group = grp;
+				return 0;
+			}
+		}
+	}
+
+	if (avefreei) {
+		/*
+		 * The free-inodes counter is approximate, and for really small
+		 * filesystems the above test can fail to find any blockgroups
+		 */
+		avefreei = 0;
+		goto fallback_retry;
+	}
+
+	return -1;
+}
+
+static int find_group_other(struct super_block *sb, struct inode *parent,
+			    ext4_group_t *group, umode_t mode)
+{
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+	ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
+	struct ext4_group_desc *desc;
+	int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
+
+	/*
+	 * Try to place the inode is the same flex group as its
+	 * parent.  If we can't find space, use the Orlov algorithm to
+	 * find another flex group, and store that information in the
+	 * parent directory's inode information so that use that flex
+	 * group for future allocations.
+	 */
+	if (flex_size > 1) {
+		int retry = 0;
+
+	try_again:
+		parent_group &= ~(flex_size-1);
+		last = parent_group + flex_size;
+		if (last > ngroups)
+			last = ngroups;
+		for  (i = parent_group; i < last; i++) {
+			desc = ext4_get_group_desc(sb, i, NULL);
+			if (desc && ext4_free_inodes_count(sb, desc)) {
+				*group = i;
+				return 0;
+			}
+		}
+		if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
+			retry = 1;
+			parent_group = EXT4_I(parent)->i_last_alloc_group;
+			goto try_again;
+		}
+		/*
+		 * If this didn't work, use the Orlov search algorithm
+		 * to find a new flex group; we pass in the mode to
+		 * avoid the topdir algorithms.
+		 */
+		*group = parent_group + flex_size;
+		if (*group > ngroups)
+			*group = 0;
+		return find_group_orlov(sb, parent, group, mode, NULL);
+	}
+
+	/*
+	 * Try to place the inode in its parent directory
+	 */
+	*group = parent_group;
+	desc = ext4_get_group_desc(sb, *group, NULL);
+	if (desc && ext4_free_inodes_count(sb, desc) &&
+	    ext4_free_group_clusters(sb, desc))
+		return 0;
+
+	/*
+	 * We're going to place this inode in a different blockgroup from its
+	 * parent.  We want to cause files in a common directory to all land in
+	 * the same blockgroup.  But we want files which are in a different
+	 * directory which shares a blockgroup with our parent to land in a
+	 * different blockgroup.
+	 *
+	 * So add our directory's i_ino into the starting point for the hash.
+	 */
+	*group = (*group + parent->i_ino) % ngroups;
+
+	/*
+	 * Use a quadratic hash to find a group with a free inode and some free
+	 * blocks.
+	 */
+	for (i = 1; i < ngroups; i <<= 1) {
+		*group += i;
+		if (*group >= ngroups)
+			*group -= ngroups;
+		desc = ext4_get_group_desc(sb, *group, NULL);
+		if (desc && ext4_free_inodes_count(sb, desc) &&
+		    ext4_free_group_clusters(sb, desc))
+			return 0;
+	}
+
+	/*
+	 * That failed: try linear search for a free inode, even if that group
+	 * has no free blocks.
+	 */
+	*group = parent_group;
+	for (i = 0; i < ngroups; i++) {
+		if (++*group >= ngroups)
+			*group = 0;
+		desc = ext4_get_group_desc(sb, *group, NULL);
+		if (desc && ext4_free_inodes_count(sb, desc))
+			return 0;
+	}
+
+	return -1;
+}
+
+/*
+ * In no journal mode, if an inode has recently been deleted, we want
+ * to avoid reusing it until we're reasonably sure the inode table
+ * block has been written back to disk.  (Yes, these values are
+ * somewhat arbitrary...)
+ */
+#define RECENTCY_MIN	5
+#define RECENTCY_DIRTY	30
+
+static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
+{
+	struct ext4_group_desc	*gdp;
+	struct ext4_inode	*raw_inode;
+	struct buffer_head	*bh;
+	unsigned long		dtime, now;
+	int	inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
+	int	offset, ret = 0, recentcy = RECENTCY_MIN;
+
+	gdp = ext4_get_group_desc(sb, group, NULL);
+	if (unlikely(!gdp))
+		return 0;
+
+	bh = sb_getblk(sb, ext4_inode_table(sb, gdp) +
+		       (ino / inodes_per_block));
+	if (unlikely(!bh) || !buffer_uptodate(bh))
+		/*
+		 * If the block is not in the buffer cache, then it
+		 * must have been written out.
+		 */
+		goto out;
+
+	offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
+	raw_inode = (struct ext4_inode *) (bh->b_data + offset);
+	dtime = le32_to_cpu(raw_inode->i_dtime);
+	now = get_seconds();
+	if (buffer_dirty(bh))
+		recentcy += RECENTCY_DIRTY;
+
+	if (dtime && (dtime < now) && (now < dtime + recentcy))
+		ret = 1;
+out:
+	brelse(bh);
+	return ret;
+}
+
+/*
+ * There are two policies for allocating an inode.  If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory's block
+ * group to find a free inode.
+ */
+struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
+			       umode_t mode, const struct qstr *qstr,
+			       __u32 goal, uid_t *owner, int handle_type,
+			       unsigned int line_no, int nblocks)
+{
+	struct super_block *sb;
+	struct buffer_head *inode_bitmap_bh = NULL;
+	struct buffer_head *group_desc_bh;
+	ext4_group_t ngroups, group = 0;
+	unsigned long ino = 0;
+	struct inode *inode;
+	struct ext4_group_desc *gdp = NULL;
+	struct ext4_inode_info *ei;
+	struct ext4_sb_info *sbi;
+	int ret2, err = 0;
+	struct inode *ret;
+	ext4_group_t i;
+	ext4_group_t flex_group;
+	struct ext4_group_info *grp;
+
+	/* Cannot create files in a deleted directory */
+	if (!dir || !dir->i_nlink)
+		return ERR_PTR(-EPERM);
+
+	sb = dir->i_sb;
+	ngroups = ext4_get_groups_count(sb);
+	trace_ext4_request_inode(dir, mode);
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	ei = EXT4_I(inode);
+	sbi = EXT4_SB(sb);
+
+	/*
+	 * Initalize owners and quota early so that we don't have to account
+	 * for quota initialization worst case in standard inode creating
+	 * transaction
+	 */
+	if (owner) {
+		inode->i_mode = mode;
+		i_uid_write(inode, owner[0]);
+		i_gid_write(inode, owner[1]);
+	} else if (test_opt(sb, GRPID)) {
+		inode->i_mode = mode;
+		inode->i_uid = current_fsuid();
+		inode->i_gid = dir->i_gid;
+	} else
+		inode_init_owner(inode, dir, mode);
+	dquot_initialize(inode);
+
+	if (!goal)
+		goal = sbi->s_inode_goal;
+
+	if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
+		group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
+		ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
+		ret2 = 0;
+		goto got_group;
+	}
+
+	if (S_ISDIR(mode))
+		ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
+	else
+		ret2 = find_group_other(sb, dir, &group, mode);
+
+got_group:
+	EXT4_I(dir)->i_last_alloc_group = group;
+	err = -ENOSPC;
+	if (ret2 == -1)
+		goto out;
+
+	/*
+	 * Normally we will only go through one pass of this loop,
+	 * unless we get unlucky and it turns out the group we selected
+	 * had its last inode grabbed by someone else.
+	 */
+	for (i = 0; i < ngroups; i++, ino = 0) {
+		err = -EIO;
+
+		gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
+		if (!gdp)
+			goto out;
+
+		/*
+		 * Check free inodes count before loading bitmap.
+		 */
+		if (ext4_free_inodes_count(sb, gdp) == 0) {
+			if (++group == ngroups)
+				group = 0;
+			continue;
+		}
+
+		grp = ext4_get_group_info(sb, group);
+		/* Skip groups with already-known suspicious inode tables */
+		if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+			if (++group == ngroups)
+				group = 0;
+			continue;
+		}
+
+		brelse(inode_bitmap_bh);
+		inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
+		/* Skip groups with suspicious inode tables */
+		if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) || !inode_bitmap_bh) {
+			if (++group == ngroups)
+				group = 0;
+			continue;
+		}
+
+repeat_in_this_group:
+		ino = ext4_find_next_zero_bit((unsigned long *)
+					      inode_bitmap_bh->b_data,
+					      EXT4_INODES_PER_GROUP(sb), ino);
+		if (ino >= EXT4_INODES_PER_GROUP(sb))
+			goto next_group;
+		if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
+			ext4_error(sb, "reserved inode found cleared - "
+				   "inode=%lu", ino + 1);
+			continue;
+		}
+		if ((EXT4_SB(sb)->s_journal == NULL) &&
+		    recently_deleted(sb, group, ino)) {
+			ino++;
+			goto next_inode;
+		}
+		if (!handle) {
+			BUG_ON(nblocks <= 0);
+			handle = __ext4_journal_start_sb(dir->i_sb, line_no,
+							 handle_type, nblocks,
+							 0);
+			if (IS_ERR(handle)) {
+				err = PTR_ERR(handle);
+				ext4_std_error(sb, err);
+				goto out;
+			}
+		}
+		BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
+		err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
+		if (err) {
+			ext4_std_error(sb, err);
+			goto out;
+		}
+		ext4_lock_group(sb, group);
+		ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
+		ext4_unlock_group(sb, group);
+		ino++;		/* the inode bitmap is zero-based */
+		if (!ret2)
+			goto got; /* we grabbed the inode! */
+next_inode:
+		if (ino < EXT4_INODES_PER_GROUP(sb))
+			goto repeat_in_this_group;
+next_group:
+		if (++group == ngroups)
+			group = 0;
+	}
+	err = -ENOSPC;
+	goto out;
+
+got:
+	BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
+	if (err) {
+		ext4_std_error(sb, err);
+		goto out;
+	}
+
+	BUFFER_TRACE(group_desc_bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, group_desc_bh);
+	if (err) {
+		ext4_std_error(sb, err);
+		goto out;
+	}
+
+	/* We may have to initialize the block bitmap if it isn't already */
+	if (ext4_has_group_desc_csum(sb) &&
+	    gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+		struct buffer_head *block_bitmap_bh;
+
+		block_bitmap_bh = ext4_read_block_bitmap(sb, group);
+		if (!block_bitmap_bh) {
+			err = -EIO;
+			goto out;
+		}
+		BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
+		err = ext4_journal_get_write_access(handle, block_bitmap_bh);
+		if (err) {
+			brelse(block_bitmap_bh);
+			ext4_std_error(sb, err);
+			goto out;
+		}
+
+		BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
+		err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
+
+		/* recheck and clear flag under lock if we still need to */
+		ext4_lock_group(sb, group);
+		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
+			ext4_free_group_clusters_set(sb, gdp,
+				ext4_free_clusters_after_init(sb, group, gdp));
+			ext4_block_bitmap_csum_set(sb, group, gdp,
+						   block_bitmap_bh);
+			ext4_group_desc_csum_set(sb, group, gdp);
+		}
+		ext4_unlock_group(sb, group);
+		brelse(block_bitmap_bh);
+
+		if (err) {
+			ext4_std_error(sb, err);
+			goto out;
+		}
+	}
+
+	/* Update the relevant bg descriptor fields */
+	if (ext4_has_group_desc_csum(sb)) {
+		int free;
+		struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+
+		down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
+		ext4_lock_group(sb, group); /* while we modify the bg desc */
+		free = EXT4_INODES_PER_GROUP(sb) -
+			ext4_itable_unused_count(sb, gdp);
+		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
+			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
+			free = 0;
+		}
+		/*
+		 * Check the relative inode number against the last used
+		 * relative inode number in this group. if it is greater
+		 * we need to update the bg_itable_unused count
+		 */
+		if (ino > free)
+			ext4_itable_unused_set(sb, gdp,
+					(EXT4_INODES_PER_GROUP(sb) - ino));
+		up_read(&grp->alloc_sem);
+	} else {
+		ext4_lock_group(sb, group);
+	}
+
+	ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
+	if (S_ISDIR(mode)) {
+		ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
+		if (sbi->s_log_groups_per_flex) {
+			ext4_group_t f = ext4_flex_group(sbi, group);
+
+			atomic_inc(&sbi->s_flex_groups[f].used_dirs);
+		}
+	}
+	if (ext4_has_group_desc_csum(sb)) {
+		ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
+					   EXT4_INODES_PER_GROUP(sb) / 8);
+		ext4_group_desc_csum_set(sb, group, gdp);
+	}
+	ext4_unlock_group(sb, group);
+
+	BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
+	if (err) {
+		ext4_std_error(sb, err);
+		goto out;
+	}
+
+	percpu_counter_dec(&sbi->s_freeinodes_counter);
+	if (S_ISDIR(mode))
+		percpu_counter_inc(&sbi->s_dirs_counter);
+
+	if (sbi->s_log_groups_per_flex) {
+		flex_group = ext4_flex_group(sbi, group);
+		atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
+	}
+
+	inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
+	/* This is the optimal IO size (for stat), not the fs block size */
+	inode->i_blocks = 0;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
+						       ext4_current_time(inode);
+
+	memset(ei->i_data, 0, sizeof(ei->i_data));
+	ei->i_dir_start_lookup = 0;
+	ei->i_disksize = 0;
+
+	/* Don't inherit extent flag from directory, amongst others. */
+	ei->i_flags =
+		ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
+	ei->i_file_acl = 0;
+	ei->i_dtime = 0;
+	ei->i_block_group = group;
+	ei->i_last_alloc_group = ~0;
+
+	/* If the directory encrypted, then we should encrypt the inode. */
+	if ((S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) &&
+	    (ext4_encrypted_inode(dir) ||
+	     DUMMY_ENCRYPTION_ENABLED(sbi)))
+		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
+
+	ext4_set_inode_flags(inode);
+	if (IS_DIRSYNC(inode))
+		ext4_handle_sync(handle);
+	if (insert_inode_locked(inode) < 0) {
+		/*
+		 * Likely a bitmap corruption causing inode to be allocated
+		 * twice.
+		 */
+		err = -EIO;
+		ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
+			   inode->i_ino);
+		goto out;
+	}
+	spin_lock(&sbi->s_next_gen_lock);
+	inode->i_generation = sbi->s_next_generation++;
+	spin_unlock(&sbi->s_next_gen_lock);
+
+	/* Precompute checksum seed for inode metadata */
+	if (ext4_has_metadata_csum(sb)) {
+		__u32 csum;
+		__le32 inum = cpu_to_le32(inode->i_ino);
+		__le32 gen = cpu_to_le32(inode->i_generation);
+		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
+				   sizeof(inum));
+		ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
+					      sizeof(gen));
+	}
+
+	ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
+	ext4_set_inode_state(inode, EXT4_STATE_NEW);
+
+	ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+	if ((sbi->s_file_encryption_mode == EXT4_ENCRYPTION_MODE_INVALID) &&
+	    (sbi->s_dir_encryption_mode == EXT4_ENCRYPTION_MODE_INVALID)) {
+		ei->i_inline_off = 0;
+		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+			EXT4_FEATURE_INCOMPAT_INLINE_DATA))
+			ext4_set_inode_state(inode,
+			EXT4_STATE_MAY_INLINE_DATA);
+	} else {
+		/* Inline data and encryption are incompatible
+		 * We turn off inline data since encryption is enabled */
+		ei->i_inline_off = 1;
+		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+			EXT4_FEATURE_INCOMPAT_INLINE_DATA))
+			ext4_clear_inode_state(inode,
+			EXT4_STATE_MAY_INLINE_DATA);
+	}
+#else
+	ei->i_inline_off = 0;
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_INLINE_DATA))
+		ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+#endif
+	ret = inode;
+	err = dquot_alloc_inode(inode);
+	if (err)
+		goto fail_drop;
+
+	err = ext4_init_acl(handle, inode, dir);
+	if (err)
+		goto fail_free_drop;
+
+	err = ext4_init_security(handle, inode, dir, qstr);
+	if (err)
+		goto fail_free_drop;
+
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
+		/* set extent flag only for directory, file and normal symlink*/
+		if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
+			ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
+			ext4_ext_tree_init(handle, inode);
+		}
+	}
+
+	if (ext4_handle_valid(handle)) {
+		ei->i_sync_tid = handle->h_transaction->t_tid;
+		ei->i_datasync_tid = handle->h_transaction->t_tid;
+	}
+
+	err = ext4_mark_inode_dirty(handle, inode);
+	if (err) {
+		ext4_std_error(sb, err);
+		goto fail_free_drop;
+	}
+
+	ext4_debug("allocating inode %lu\n", inode->i_ino);
+	trace_ext4_allocate_inode(inode, dir, mode);
+	brelse(inode_bitmap_bh);
+	return ret;
+
+fail_free_drop:
+	dquot_free_inode(inode);
+fail_drop:
+	clear_nlink(inode);
+	unlock_new_inode(inode);
+out:
+	dquot_drop(inode);
+	inode->i_flags |= S_NOQUOTA;
+	iput(inode);
+	brelse(inode_bitmap_bh);
+	return ERR_PTR(err);
+}
+
+/* Verify that we are loading a valid orphan from disk */
+struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
+{
+	unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
+	ext4_group_t block_group;
+	int bit;
+	struct buffer_head *bitmap_bh;
+	struct inode *inode = NULL;
+	long err = -EIO;
+
+	/* Error cases - e2fsck has already cleaned up for us */
+	if (ino > max_ino) {
+		ext4_warning(sb, "bad orphan ino %lu!  e2fsck was run?", ino);
+		goto error;
+	}
+
+	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
+	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
+	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
+	if (!bitmap_bh) {
+		ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
+		goto error;
+	}
+
+	/* Having the inode bit set should be a 100% indicator that this
+	 * is a valid orphan (no e2fsck run on fs).  Orphans also include
+	 * inodes that were being truncated, so we can't check i_nlink==0.
+	 */
+	if (!ext4_test_bit(bit, bitmap_bh->b_data))
+		goto bad_orphan;
+
+	inode = ext4_iget(sb, ino);
+	if (IS_ERR(inode))
+		goto iget_failed;
+
+	/*
+	 * If the orphans has i_nlinks > 0 then it should be able to be
+	 * truncated, otherwise it won't be removed from the orphan list
+	 * during processing and an infinite loop will result.
+	 */
+	if (inode->i_nlink && !ext4_can_truncate(inode))
+		goto bad_orphan;
+
+	if (NEXT_ORPHAN(inode) > max_ino)
+		goto bad_orphan;
+	brelse(bitmap_bh);
+	return inode;
+
+iget_failed:
+	err = PTR_ERR(inode);
+	inode = NULL;
+bad_orphan:
+	ext4_warning(sb, "bad orphan inode %lu!  e2fsck was run?", ino);
+	printk(KERN_WARNING "ext4_test_bit(bit=%d, block=%llu) = %d\n",
+	       bit, (unsigned long long)bitmap_bh->b_blocknr,
+	       ext4_test_bit(bit, bitmap_bh->b_data));
+	printk(KERN_WARNING "inode=%p\n", inode);
+	if (inode) {
+		printk(KERN_WARNING "is_bad_inode(inode)=%d\n",
+		       is_bad_inode(inode));
+		printk(KERN_WARNING "NEXT_ORPHAN(inode)=%u\n",
+		       NEXT_ORPHAN(inode));
+		printk(KERN_WARNING "max_ino=%lu\n", max_ino);
+		printk(KERN_WARNING "i_nlink=%u\n", inode->i_nlink);
+		/* Avoid freeing blocks if we got a bad deleted inode */
+		if (inode->i_nlink == 0)
+			inode->i_blocks = 0;
+		iput(inode);
+	}
+	brelse(bitmap_bh);
+error:
+	return ERR_PTR(err);
+}
+
+unsigned long ext4_count_free_inodes(struct super_block *sb)
+{
+	unsigned long desc_count;
+	struct ext4_group_desc *gdp;
+	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+#ifdef EXT4FS_DEBUG
+	struct ext4_super_block *es;
+	unsigned long bitmap_count, x;
+	struct buffer_head *bitmap_bh = NULL;
+
+	es = EXT4_SB(sb)->s_es;
+	desc_count = 0;
+	bitmap_count = 0;
+	gdp = NULL;
+	for (i = 0; i < ngroups; i++) {
+		gdp = ext4_get_group_desc(sb, i, NULL);
+		if (!gdp)
+			continue;
+		desc_count += ext4_free_inodes_count(sb, gdp);
+		brelse(bitmap_bh);
+		bitmap_bh = ext4_read_inode_bitmap(sb, i);
+		if (!bitmap_bh)
+			continue;
+
+		x = ext4_count_free(bitmap_bh->b_data,
+				    EXT4_INODES_PER_GROUP(sb) / 8);
+		printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
+			(unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
+		bitmap_count += x;
+	}
+	brelse(bitmap_bh);
+	printk(KERN_DEBUG "ext4_count_free_inodes: "
+	       "stored = %u, computed = %lu, %lu\n",
+	       le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
+	return desc_count;
+#else
+	desc_count = 0;
+	for (i = 0; i < ngroups; i++) {
+		gdp = ext4_get_group_desc(sb, i, NULL);
+		if (!gdp)
+			continue;
+		desc_count += ext4_free_inodes_count(sb, gdp);
+		cond_resched();
+	}
+	return desc_count;
+#endif
+}
+
+/* Called at mount-time, super-block is locked */
+unsigned long ext4_count_dirs(struct super_block * sb)
+{
+	unsigned long count = 0;
+	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+
+	for (i = 0; i < ngroups; i++) {
+		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
+		if (!gdp)
+			continue;
+		count += ext4_used_dirs_count(sb, gdp);
+	}
+	return count;
+}
+
+/*
+ * Zeroes not yet zeroed inode table - just write zeroes through the whole
+ * inode table. Must be called without any spinlock held. The only place
+ * where it is called from on active part of filesystem is ext4lazyinit
+ * thread, so we do not need any special locks, however we have to prevent
+ * inode allocation from the current group, so we take alloc_sem lock, to
+ * block ext4_new_inode() until we are finished.
+ */
+int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
+				 int barrier)
+{
+	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_group_desc *gdp = NULL;
+	struct buffer_head *group_desc_bh;
+	handle_t *handle;
+	ext4_fsblk_t blk;
+	int num, ret = 0, used_blks = 0;
+
+	/* This should not happen, but just to be sure check this */
+	if (sb->s_flags & MS_RDONLY) {
+		ret = 1;
+		goto out;
+	}
+
+	gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
+	if (!gdp)
+		goto out;
+
+	/*
+	 * We do not need to lock this, because we are the only one
+	 * handling this flag.
+	 */
+	if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
+		goto out;
+
+	handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		goto out;
+	}
+
+	down_write(&grp->alloc_sem);
+	/*
+	 * If inode bitmap was already initialized there may be some
+	 * used inodes so we need to skip blocks with used inodes in
+	 * inode table.
+	 */
+	if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
+		used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
+			    ext4_itable_unused_count(sb, gdp)),
+			    sbi->s_inodes_per_block);
+
+	if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
+		ext4_error(sb, "Something is wrong with group %u: "
+			   "used itable blocks: %d; "
+			   "itable unused count: %u",
+			   group, used_blks,
+			   ext4_itable_unused_count(sb, gdp));
+		ret = 1;
+		goto err_out;
+	}
+
+	blk = ext4_inode_table(sb, gdp) + used_blks;
+	num = sbi->s_itb_per_group - used_blks;
+
+	BUFFER_TRACE(group_desc_bh, "get_write_access");
+	ret = ext4_journal_get_write_access(handle,
+					    group_desc_bh);
+	if (ret)
+		goto err_out;
+
+	/*
+	 * Skip zeroout if the inode table is full. But we set the ZEROED
+	 * flag anyway, because obviously, when it is full it does not need
+	 * further zeroing.
+	 */
+	if (unlikely(num == 0))
+		goto skip_zeroout;
+
+	ext4_debug("going to zero out inode table in group %d\n",
+		   group);
+	ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
+	if (ret < 0)
+		goto err_out;
+	if (barrier)
+		blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
+
+skip_zeroout:
+	ext4_lock_group(sb, group);
+	gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
+	ext4_group_desc_csum_set(sb, group, gdp);
+	ext4_unlock_group(sb, group);
+
+	BUFFER_TRACE(group_desc_bh,
+		     "call ext4_handle_dirty_metadata");
+	ret = ext4_handle_dirty_metadata(handle, NULL,
+					 group_desc_bh);
+
+err_out:
+	up_write(&grp->alloc_sem);
+	ext4_journal_stop(handle);
+out:
+	return ret;
+}