Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 1080 insertions, 0 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
new file mode 100644
index 0000000..03c0819
--- /dev/null
+++ b/fs/ext4/ialloc.c
@@ -0,0 +1,1080 @@
+/*
+ *  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/jbd2.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 "group.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 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 */
+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_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(sbi, block_group, gdp)) {
+		ext4_error(sb, __func__, "Checksum bad for group %lu\n",
+			   block_group);
+		gdp->bg_free_blocks_count = 0;
+		gdp->bg_free_inodes_count = 0;
+		gdp->bg_itable_unused = 0;
+		memset(bh->b_data, 0xff, sb->s_blocksize);
+		return 0;
+	}
+
+	memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
+	mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
+			bh->b_data);
+
+	return EXT4_INODES_PER_GROUP(sb);
+}
+
+/*
+ * 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;
+
+	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, __func__,
+			    "Cannot read inode bitmap - "
+			    "block_group = %lu, inode_bitmap = %llu",
+			    block_group, bitmap_blk);
+		return NULL;
+	}
+	if (bitmap_uptodate(bh))
+		return bh;
+
+	lock_buffer(bh);
+	if (bitmap_uptodate(bh)) {
+		unlock_buffer(bh);
+		return bh;
+	}
+	spin_lock(sb_bgl_lock(EXT4_SB(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);
+		unlock_buffer(bh);
+		spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group));
+		return bh;
+	}
+	spin_unlock(sb_bgl_lock(EXT4_SB(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);
+		return bh;
+	}
+	/*
+	 * submit the buffer_head for read. We can
+	 * safely mark the bitmap as uptodate now.
+	 * We do it here so the bitmap uptodate bit
+	 * get set with buffer lock held.
+	 */
+	set_bitmap_uptodate(bh);
+	if (bh_submit_read(bh) < 0) {
+		put_bh(bh);
+		ext4_error(sb, __func__,
+			    "Cannot read inode bitmap - "
+			    "block_group = %lu, inode_bitmap = %llu",
+			    block_group, bitmap_blk);
+		return NULL;
+	}
+	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;
+	ext4_group_t flex_group;
+
+	if (atomic_read(&inode->i_count) > 1) {
+		printk(KERN_ERR "ext4_free_inode: inode has count=%d\n",
+		       atomic_read(&inode->i_count));
+		return;
+	}
+	if (inode->i_nlink) {
+		printk(KERN_ERR "ext4_free_inode: inode has nlink=%d\n",
+		       inode->i_nlink);
+		return;
+	}
+	if (!sb) {
+		printk(KERN_ERR "ext4_free_inode: inode on "
+		       "nonexistent device\n");
+		return;
+	}
+	sbi = EXT4_SB(sb);
+
+	ino = inode->i_ino;
+	ext4_debug("freeing inode %lu\n", ino);
+
+	/*
+	 * Note: we must free any quota before locking the superblock,
+	 * as writing the quota to disk may need the lock as well.
+	 */
+	DQUOT_INIT(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 */
+	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, "ext4_free_inode",
+			   "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);
+	if (!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;
+
+	/* Ok, now we can actually update the inode bitmaps.. */
+	if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
+					bit, bitmap_bh->b_data))
+		ext4_error(sb, "ext4_free_inode",
+			   "bit already cleared for inode %lu", ino);
+	else {
+		gdp = ext4_get_group_desc(sb, block_group, &bh2);
+
+		BUFFER_TRACE(bh2, "get_write_access");
+		fatal = ext4_journal_get_write_access(handle, bh2);
+		if (fatal) goto error_return;
+
+		if (gdp) {
+			spin_lock(sb_bgl_lock(sbi, block_group));
+			le16_add_cpu(&gdp->bg_free_inodes_count, 1);
+			if (is_directory)
+				le16_add_cpu(&gdp->bg_used_dirs_count, -1);
+			gdp->bg_checksum = ext4_group_desc_csum(sbi,
+							block_group, gdp);
+			spin_unlock(sb_bgl_lock(sbi, block_group));
+			percpu_counter_inc(&sbi->s_freeinodes_counter);
+			if (is_directory)
+				percpu_counter_dec(&sbi->s_dirs_counter);
+
+			if (sbi->s_log_groups_per_flex) {
+				flex_group = ext4_flex_group(sbi, block_group);
+				spin_lock(sb_bgl_lock(sbi, flex_group));
+				sbi->s_flex_groups[flex_group].free_inodes++;
+				spin_unlock(sb_bgl_lock(sbi, flex_group));
+			}
+		}
+		BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
+		err = ext4_journal_dirty_metadata(handle, bh2);
+		if (!fatal) fatal = err;
+	}
+	BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata");
+	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+	if (!fatal)
+		fatal = err;
+	sb->s_dirt = 1;
+error_return:
+	brelse(bitmap_bh);
+	ext4_std_error(sb, fatal);
+}
+
+/*
+ * 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.
+ */
+static int find_group_dir(struct super_block *sb, struct inode *parent,
+				ext4_group_t *best_group)
+{
+	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
+	unsigned int freei, avefreei;
+	struct ext4_group_desc *desc, *best_desc = NULL;
+	ext4_group_t group;
+	int ret = -1;
+
+	freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
+	avefreei = freei / ngroups;
+
+	for (group = 0; group < ngroups; group++) {
+		desc = ext4_get_group_desc(sb, group, NULL);
+		if (!desc || !desc->bg_free_inodes_count)
+			continue;
+		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+			continue;
+		if (!best_desc ||
+		    (le16_to_cpu(desc->bg_free_blocks_count) >
+		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
+			*best_group = group;
+			best_desc = desc;
+			ret = 0;
+		}
+	}
+	return ret;
+}
+
+#define free_block_ratio 10
+
+static int find_group_flex(struct super_block *sb, struct inode *parent,
+			   ext4_group_t *best_group)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_group_desc *desc;
+	struct buffer_head *bh;
+	struct flex_groups *flex_group = sbi->s_flex_groups;
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+	ext4_group_t parent_fbg_group = ext4_flex_group(sbi, parent_group);
+	ext4_group_t ngroups = sbi->s_groups_count;
+	int flex_size = ext4_flex_bg_size(sbi);
+	ext4_group_t best_flex = parent_fbg_group;
+	int blocks_per_flex = sbi->s_blocks_per_group * flex_size;
+	int flexbg_free_blocks;
+	int flex_freeb_ratio;
+	ext4_group_t n_fbg_groups;
+	ext4_group_t i;
+
+	n_fbg_groups = (sbi->s_groups_count + flex_size - 1) >>
+		sbi->s_log_groups_per_flex;
+
+find_close_to_parent:
+	flexbg_free_blocks = flex_group[best_flex].free_blocks;
+	flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex;
+	if (flex_group[best_flex].free_inodes &&
+	    flex_freeb_ratio > free_block_ratio)
+		goto found_flexbg;
+
+	if (best_flex && best_flex == parent_fbg_group) {
+		best_flex--;
+		goto find_close_to_parent;
+	}
+
+	for (i = 0; i < n_fbg_groups; i++) {
+		if (i == parent_fbg_group || i == parent_fbg_group - 1)
+			continue;
+
+		flexbg_free_blocks = flex_group[i].free_blocks;
+		flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex;
+
+		if (flex_freeb_ratio > free_block_ratio &&
+		    flex_group[i].free_inodes) {
+			best_flex = i;
+			goto found_flexbg;
+		}
+
+		if (flex_group[best_flex].free_inodes == 0 ||
+		    (flex_group[i].free_blocks >
+		     flex_group[best_flex].free_blocks &&
+		     flex_group[i].free_inodes))
+			best_flex = i;
+	}
+
+	if (!flex_group[best_flex].free_inodes ||
+	    !flex_group[best_flex].free_blocks)
+		return -1;
+
+found_flexbg:
+	for (i = best_flex * flex_size; i < ngroups &&
+		     i < (best_flex + 1) * flex_size; i++) {
+		desc = ext4_get_group_desc(sb, i, &bh);
+		if (le16_to_cpu(desc->bg_free_inodes_count)) {
+			*best_group = i;
+			goto out;
+		}
+	}
+
+	return -1;
+out:
+	return 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
+ * it's already running too large debt (max_debt).
+ * 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).
+ *
+ * Debt is incremented each time we allocate a directory and decremented
+ * when we allocate an inode, within 0--255.
+ */
+
+#define INODE_COST 64
+#define BLOCK_COST 256
+
+static int find_group_orlov(struct super_block *sb, struct inode *parent,
+				ext4_group_t *group)
+{
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	ext4_group_t ngroups = sbi->s_groups_count;
+	int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
+	unsigned int freei, avefreei;
+	ext4_fsblk_t freeb, avefreeb;
+	ext4_fsblk_t blocks_per_dir;
+	unsigned int ndirs;
+	int max_debt, max_dirs, min_inodes;
+	ext4_grpblk_t min_blocks;
+	ext4_group_t i;
+	struct ext4_group_desc *desc;
+
+	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
+	avefreei = freei / ngroups;
+	freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+	avefreeb = freeb;
+	do_div(avefreeb, ngroups);
+	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
+
+	if ((parent == sb->s_root->d_inode) ||
+	    (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
+		int best_ndir = inodes_per_group;
+		ext4_group_t grp;
+		int ret = -1;
+
+		get_random_bytes(&grp, sizeof(grp));
+		parent_group = (unsigned)grp % ngroups;
+		for (i = 0; i < ngroups; i++) {
+			grp = (parent_group + i) % ngroups;
+			desc = ext4_get_group_desc(sb, grp, NULL);
+			if (!desc || !desc->bg_free_inodes_count)
+				continue;
+			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
+				continue;
+			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+				continue;
+			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
+				continue;
+			*group = grp;
+			ret = 0;
+			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
+		}
+		if (ret == 0)
+			return ret;
+		goto fallback;
+	}
+
+	blocks_per_dir = ext4_blocks_count(es) - freeb;
+	do_div(blocks_per_dir, ndirs);
+
+	max_dirs = ndirs / ngroups + inodes_per_group / 16;
+	min_inodes = avefreei - inodes_per_group / 4;
+	min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;
+
+	max_debt = EXT4_BLOCKS_PER_GROUP(sb);
+	max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
+	if (max_debt * INODE_COST > inodes_per_group)
+		max_debt = inodes_per_group / INODE_COST;
+	if (max_debt > 255)
+		max_debt = 255;
+	if (max_debt == 0)
+		max_debt = 1;
+
+	for (i = 0; i < ngroups; i++) {
+		*group = (parent_group + i) % ngroups;
+		desc = ext4_get_group_desc(sb, *group, NULL);
+		if (!desc || !desc->bg_free_inodes_count)
+			continue;
+		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
+			continue;
+		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
+			continue;
+		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
+			continue;
+		return 0;
+	}
+
+fallback:
+	for (i = 0; i < ngroups; i++) {
+		*group = (parent_group + i) % ngroups;
+		desc = ext4_get_group_desc(sb, *group, NULL);
+		if (desc && desc->bg_free_inodes_count &&
+			le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
+			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;
+	}
+
+	return -1;
+}
+
+static int find_group_other(struct super_block *sb, struct inode *parent,
+				ext4_group_t *group)
+{
+	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
+	struct ext4_group_desc *desc;
+	ext4_group_t i;
+
+	/*
+	 * Try to place the inode in its parent directory
+	 */
+	*group = parent_group;
+	desc = ext4_get_group_desc(sb, *group, NULL);
+	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+			le16_to_cpu(desc->bg_free_blocks_count))
+		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 && le16_to_cpu(desc->bg_free_inodes_count) &&
+				le16_to_cpu(desc->bg_free_blocks_count))
+			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 && le16_to_cpu(desc->bg_free_inodes_count))
+			return 0;
+	}
+
+	return -1;
+}
+
+/*
+ * claim the inode from the inode bitmap. If the group
+ * is uninit we need to take the groups's sb_bgl_lock
+ * and clear the uninit flag. The inode bitmap update
+ * and group desc uninit flag clear should be done
+ * after holding sb_bgl_lock so that ext4_read_inode_bitmap
+ * doesn't race with the ext4_claim_inode
+ */
+static int ext4_claim_inode(struct super_block *sb,
+			struct buffer_head *inode_bitmap_bh,
+			unsigned long ino, ext4_group_t group, int mode)
+{
+	int free = 0, retval = 0;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
+
+	spin_lock(sb_bgl_lock(sbi, group));
+	if (ext4_set_bit(ino, inode_bitmap_bh->b_data)) {
+		/* not a free inode */
+		retval = 1;
+		goto err_ret;
+	}
+	ino++;
+	if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
+			ino > EXT4_INODES_PER_GROUP(sb)) {
+		spin_unlock(sb_bgl_lock(sbi, group));
+		ext4_error(sb, __func__,
+			   "reserved inode or inode > inodes count - "
+			   "block_group = %lu, inode=%lu", group,
+			   ino + group * EXT4_INODES_PER_GROUP(sb));
+		return 1;
+	}
+	/* If we didn't allocate from within the initialized part of the inode
+	 * table then we need to initialize up to this inode. */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+
+		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
+			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
+			/* When marking the block group with
+			 * ~EXT4_BG_INODE_UNINIT we don't want to depend
+			 * on the value of bg_itable_unused even though
+			 * mke2fs could have initialized the same for us.
+			 * Instead we calculated the value below
+			 */
+
+			free = 0;
+		} else {
+			free = EXT4_INODES_PER_GROUP(sb) -
+				le16_to_cpu(gdp->bg_itable_unused);
+		}
+
+		/*
+		 * 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)
+			gdp->bg_itable_unused =
+				cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino);
+	}
+	le16_add_cpu(&gdp->bg_free_inodes_count, -1);
+	if (S_ISDIR(mode)) {
+		le16_add_cpu(&gdp->bg_used_dirs_count, 1);
+	}
+	gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
+err_ret:
+	spin_unlock(sb_bgl_lock(sbi, group));
+	return retval;
+}
+
+/*
+ * 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, int mode)
+{
+	struct super_block *sb;
+	struct buffer_head *bitmap_bh = NULL;
+	struct buffer_head *bh2;
+	ext4_group_t group = 0;
+	unsigned long ino = 0;
+	struct inode *inode;
+	struct ext4_group_desc *gdp = NULL;
+	struct ext4_super_block *es;
+	struct ext4_inode_info *ei;
+	struct ext4_sb_info *sbi;
+	int ret2, err = 0;
+	struct inode *ret;
+	ext4_group_t i;
+	int free = 0;
+	ext4_group_t flex_group;
+
+	/* Cannot create files in a deleted directory */
+	if (!dir || !dir->i_nlink)
+		return ERR_PTR(-EPERM);
+
+	sb = dir->i_sb;
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	ei = EXT4_I(inode);
+
+	sbi = EXT4_SB(sb);
+	es = sbi->s_es;
+
+	if (sbi->s_log_groups_per_flex) {
+		ret2 = find_group_flex(sb, dir, &group);
+		if (ret2 == -1) {
+			ret2 = find_group_other(sb, dir, &group);
+			if (ret2 == 0 && printk_ratelimit())
+				printk(KERN_NOTICE "ext4: find_group_flex "
+				       "failed, fallback succeeded dir %lu\n",
+				       dir->i_ino);
+		}
+		goto got_group;
+	}
+
+	if (S_ISDIR(mode)) {
+		if (test_opt(sb, OLDALLOC))
+			ret2 = find_group_dir(sb, dir, &group);
+		else
+			ret2 = find_group_orlov(sb, dir, &group);
+	} else
+		ret2 = find_group_other(sb, dir, &group);
+
+got_group:
+	err = -ENOSPC;
+	if (ret2 == -1)
+		goto out;
+
+	for (i = 0; i < sbi->s_groups_count; i++) {
+		err = -EIO;
+
+		gdp = ext4_get_group_desc(sb, group, &bh2);
+		if (!gdp)
+			goto fail;
+
+		brelse(bitmap_bh);
+		bitmap_bh = ext4_read_inode_bitmap(sb, group);
+		if (!bitmap_bh)
+			goto fail;
+
+		ino = 0;
+
+repeat_in_this_group:
+		ino = ext4_find_next_zero_bit((unsigned long *)
+				bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
+		if (ino < EXT4_INODES_PER_GROUP(sb)) {
+
+			BUFFER_TRACE(bitmap_bh, "get_write_access");
+			err = ext4_journal_get_write_access(handle, bitmap_bh);
+			if (err)
+				goto fail;
+
+			BUFFER_TRACE(bh2, "get_write_access");
+			err = ext4_journal_get_write_access(handle, bh2);
+			if (err)
+				goto fail;
+			if (!ext4_claim_inode(sb, bitmap_bh,
+						ino, group, mode)) {
+				/* we won it */
+				BUFFER_TRACE(bitmap_bh,
+					"call ext4_journal_dirty_metadata");
+				err = ext4_journal_dirty_metadata(handle,
+								bitmap_bh);
+				if (err)
+					goto fail;
+				/* zero bit is inode number 1*/
+				ino++;
+				goto got;
+			}
+			/* we lost it */
+			jbd2_journal_release_buffer(handle, bitmap_bh);
+			jbd2_journal_release_buffer(handle, bh2);
+
+			if (++ino < EXT4_INODES_PER_GROUP(sb))
+				goto repeat_in_this_group;
+		}
+
+		/*
+		 * This case is possible in concurrent environment.  It is very
+		 * rare.  We cannot repeat the find_group_xxx() call because
+		 * that will simply return the same blockgroup, because the
+		 * group descriptor metadata has not yet been updated.
+		 * So we just go onto the next blockgroup.
+		 */
+		if (++group == sbi->s_groups_count)
+			group = 0;
+	}
+	err = -ENOSPC;
+	goto out;
+
+got:
+	/* We may have to initialize the block bitmap if it isn't already */
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
+	    gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+		struct buffer_head *block_bh = ext4_read_block_bitmap(sb, group);
+
+		BUFFER_TRACE(block_bh, "get block bitmap access");
+		err = ext4_journal_get_write_access(handle, block_bh);
+		if (err) {
+			brelse(block_bh);
+			goto fail;
+		}
+
+		free = 0;
+		spin_lock(sb_bgl_lock(sbi, group));
+		/* recheck and clear flag under lock if we still need to */
+		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
+			free = ext4_free_blocks_after_init(sb, group, gdp);
+			gdp->bg_free_blocks_count = cpu_to_le16(free);
+			gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
+								gdp);
+		}
+		spin_unlock(sb_bgl_lock(sbi, group));
+
+		/* Don't need to dirty bitmap block if we didn't change it */
+		if (free) {
+			BUFFER_TRACE(block_bh, "dirty block bitmap");
+			err = ext4_journal_dirty_metadata(handle, block_bh);
+		}
+
+		brelse(block_bh);
+		if (err)
+			goto fail;
+	}
+	BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
+	err = ext4_journal_dirty_metadata(handle, bh2);
+	if (err)
+		goto fail;
+
+	percpu_counter_dec(&sbi->s_freeinodes_counter);
+	if (S_ISDIR(mode))
+		percpu_counter_inc(&sbi->s_dirs_counter);
+	sb->s_dirt = 1;
+
+	if (sbi->s_log_groups_per_flex) {
+		flex_group = ext4_flex_group(sbi, group);
+		spin_lock(sb_bgl_lock(sbi, flex_group));
+		sbi->s_flex_groups[flex_group].free_inodes--;
+		spin_unlock(sb_bgl_lock(sbi, flex_group));
+	}
+
+	inode->i_uid = current->fsuid;
+	if (test_opt(sb, GRPID))
+		inode->i_gid = dir->i_gid;
+	else if (dir->i_mode & S_ISGID) {
+		inode->i_gid = dir->i_gid;
+		if (S_ISDIR(mode))
+			mode |= S_ISGID;
+	} else
+		inode->i_gid = current->fsgid;
+	inode->i_mode = mode;
+
+	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. We set extent flag on
+	 * newly created directory and file only if -o extent mount option is
+	 * specified
+	 */
+	ei->i_flags = EXT4_I(dir)->i_flags & ~(EXT4_INDEX_FL|EXT4_EXTENTS_FL);
+	if (S_ISLNK(mode))
+		ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
+	/* dirsync only applies to directories */
+	if (!S_ISDIR(mode))
+		ei->i_flags &= ~EXT4_DIRSYNC_FL;
+	ei->i_file_acl = 0;
+	ei->i_dtime = 0;
+	ei->i_block_group = group;
+
+	ext4_set_inode_flags(inode);
+	if (IS_DIRSYNC(inode))
+		handle->h_sync = 1;
+	insert_inode_hash(inode);
+	spin_lock(&sbi->s_next_gen_lock);
+	inode->i_generation = sbi->s_next_generation++;
+	spin_unlock(&sbi->s_next_gen_lock);
+
+	ei->i_state = EXT4_STATE_NEW;
+
+	ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
+
+	ret = inode;
+	if (DQUOT_ALLOC_INODE(inode)) {
+		err = -EDQUOT;
+		goto fail_drop;
+	}
+
+	err = ext4_init_acl(handle, inode, dir);
+	if (err)
+		goto fail_free_drop;
+
+	err = ext4_init_security(handle, inode, dir);
+	if (err)
+		goto fail_free_drop;
+
+	if (test_opt(sb, EXTENTS)) {
+		/* set extent flag only for directory, file and normal symlink*/
+		if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
+			EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
+			ext4_ext_tree_init(handle, inode);
+		}
+	}
+
+	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);
+	goto really_out;
+fail:
+	ext4_std_error(sb, err);
+out:
+	iput(inode);
+	ret = ERR_PTR(err);
+really_out:
+	brelse(bitmap_bh);
+	return ret;
+
+fail_free_drop:
+	DQUOT_FREE_INODE(inode);
+
+fail_drop:
+	DQUOT_DROP(inode);
+	inode->i_flags |= S_NOQUOTA;
+	inode->i_nlink = 0;
+	iput(inode);
+	brelse(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, __func__,
+			     "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, __func__,
+			     "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, __func__,
+		     "bad orphan inode %lu!  e2fsck was run?", ino);
+	printk(KERN_NOTICE "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_NOTICE "inode=%p\n", inode);
+	if (inode) {
+		printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
+		       is_bad_inode(inode));
+		printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
+		       NEXT_ORPHAN(inode));
+		printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
+		printk(KERN_NOTICE "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;
+#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 < EXT4_SB(sb)->s_groups_count; i++) {
+		gdp = ext4_get_group_desc(sb, i, NULL);
+		if (!gdp)
+			continue;
+		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+		brelse(bitmap_bh);
+		bitmap_bh = ext4_read_inode_bitmap(sb, i);
+		if (!bitmap_bh)
+			continue;
+
+		x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
+		printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
+			i, le16_to_cpu(gdp->bg_free_inodes_count), 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 < EXT4_SB(sb)->s_groups_count; i++) {
+		gdp = ext4_get_group_desc(sb, i, NULL);
+		if (!gdp)
+			continue;
+		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+		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;
+
+	for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
+		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
+		if (!gdp)
+			continue;
+		count += le16_to_cpu(gdp->bg_used_dirs_count);
+	}
+	return count;
+}
+