Merge commit 'v2.6.27-rc7' into x86/pebs

16 files changed, 1205 insertions, 704 deletions

diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 3c8dab880d9..694ed6fadcc 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -40,34 +40,35 @@ ext4_acl_from_disk(const void *value, size_t size)
 	acl = posix_acl_alloc(count, GFP_NOFS);
 	if (!acl)
 		return ERR_PTR(-ENOMEM);
-	for (n=0; n < count; n++) {
+	for (n = 0; n < count; n++) {
 		ext4_acl_entry *entry =
 			(ext4_acl_entry *)value;
 		if ((char *)value + sizeof(ext4_acl_entry_short) > end)
 			goto fail;
 		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
 		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
-		switch(acl->a_entries[n].e_tag) {
-			case ACL_USER_OBJ:
-			case ACL_GROUP_OBJ:
-			case ACL_MASK:
-			case ACL_OTHER:
-				value = (char *)value +
-					sizeof(ext4_acl_entry_short);
-				acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
-				break;
-
-			case ACL_USER:
-			case ACL_GROUP:
-				value = (char *)value + sizeof(ext4_acl_entry);
-				if ((char *)value > end)
-					goto fail;
-				acl->a_entries[n].e_id =
-					le32_to_cpu(entry->e_id);
-				break;
-
-			default:
+
+		switch (acl->a_entries[n].e_tag) {
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			value = (char *)value +
+				sizeof(ext4_acl_entry_short);
+			acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
+			break;
+
+		case ACL_USER:
+		case ACL_GROUP:
+			value = (char *)value + sizeof(ext4_acl_entry);
+			if ((char *)value > end)
 				goto fail;
+			acl->a_entries[n].e_id =
+				le32_to_cpu(entry->e_id);
+			break;
+
+		default:
+			goto fail;
 		}
 	}
 	if (value != end)
@@ -96,27 +97,26 @@ ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
 		return ERR_PTR(-ENOMEM);
 	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
 	e = (char *)ext_acl + sizeof(ext4_acl_header);
-	for (n=0; n < acl->a_count; n++) {
+	for (n = 0; n < acl->a_count; n++) {
 		ext4_acl_entry *entry = (ext4_acl_entry *)e;
 		entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
 		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
-		switch(acl->a_entries[n].e_tag) {
-			case ACL_USER:
-			case ACL_GROUP:
-				entry->e_id =
-					cpu_to_le32(acl->a_entries[n].e_id);
-				e += sizeof(ext4_acl_entry);
-				break;
-
-			case ACL_USER_OBJ:
-			case ACL_GROUP_OBJ:
-			case ACL_MASK:
-			case ACL_OTHER:
-				e += sizeof(ext4_acl_entry_short);
-				break;
-
-			default:
-				goto fail;
+		switch (acl->a_entries[n].e_tag) {
+		case ACL_USER:
+		case ACL_GROUP:
+			entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
+			e += sizeof(ext4_acl_entry);
+			break;
+
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			e += sizeof(ext4_acl_entry_short);
+			break;
+
+		default:
+			goto fail;
 		}
 	}
 	return (char *)ext_acl;
@@ -167,23 +167,23 @@ ext4_get_acl(struct inode *inode, int type)
 	if (!test_opt(inode->i_sb, POSIX_ACL))
 		return NULL;
 
-	switch(type) {
-		case ACL_TYPE_ACCESS:
-			acl = ext4_iget_acl(inode, &ei->i_acl);
-			if (acl != EXT4_ACL_NOT_CACHED)
-				return acl;
-			name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
-			break;
-
-		case ACL_TYPE_DEFAULT:
-			acl = ext4_iget_acl(inode, &ei->i_default_acl);
-			if (acl != EXT4_ACL_NOT_CACHED)
-				return acl;
-			name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
-			break;
-
-		default:
-			return ERR_PTR(-EINVAL);
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		acl = ext4_iget_acl(inode, &ei->i_acl);
+		if (acl != EXT4_ACL_NOT_CACHED)
+			return acl;
+		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
+		break;
+
+	case ACL_TYPE_DEFAULT:
+		acl = ext4_iget_acl(inode, &ei->i_default_acl);
+		if (acl != EXT4_ACL_NOT_CACHED)
+			return acl;
+		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
+		break;
+
+	default:
+		return ERR_PTR(-EINVAL);
 	}
 	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
 	if (retval > 0) {
@@ -201,14 +201,14 @@ ext4_get_acl(struct inode *inode, int type)
 	kfree(value);
 
 	if (!IS_ERR(acl)) {
-		switch(type) {
-			case ACL_TYPE_ACCESS:
-				ext4_iset_acl(inode, &ei->i_acl, acl);
-				break;
-
-			case ACL_TYPE_DEFAULT:
-				ext4_iset_acl(inode, &ei->i_default_acl, acl);
-				break;
+		switch (type) {
+		case ACL_TYPE_ACCESS:
+			ext4_iset_acl(inode, &ei->i_acl, acl);
+			break;
+
+		case ACL_TYPE_DEFAULT:
+			ext4_iset_acl(inode, &ei->i_default_acl, acl);
+			break;
 		}
 	}
 	return acl;
@@ -232,31 +232,31 @@ ext4_set_acl(handle_t *handle, struct inode *inode, int type,
 	if (S_ISLNK(inode->i_mode))
 		return -EOPNOTSUPP;
 
-	switch(type) {
-		case ACL_TYPE_ACCESS:
-			name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
-			if (acl) {
-				mode_t mode = inode->i_mode;
-				error = posix_acl_equiv_mode(acl, &mode);
-				if (error < 0)
-					return error;
-				else {
-					inode->i_mode = mode;
-					ext4_mark_inode_dirty(handle, inode);
-					if (error == 0)
-						acl = NULL;
-				}
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
+		if (acl) {
+			mode_t mode = inode->i_mode;
+			error = posix_acl_equiv_mode(acl, &mode);
+			if (error < 0)
+				return error;
+			else {
+				inode->i_mode = mode;
+				ext4_mark_inode_dirty(handle, inode);
+				if (error == 0)
+					acl = NULL;
 			}
-			break;
+		}
+		break;
 
-		case ACL_TYPE_DEFAULT:
-			name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
-			if (!S_ISDIR(inode->i_mode))
-				return acl ? -EACCES : 0;
-			break;
+	case ACL_TYPE_DEFAULT:
+		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EACCES : 0;
+		break;
 
-		default:
-			return -EINVAL;
+	default:
+		return -EINVAL;
 	}
 	if (acl) {
 		value = ext4_acl_to_disk(acl, &size);
@@ -269,14 +269,14 @@ ext4_set_acl(handle_t *handle, struct inode *inode, int type,
 
 	kfree(value);
 	if (!error) {
-		switch(type) {
-			case ACL_TYPE_ACCESS:
-				ext4_iset_acl(inode, &ei->i_acl, acl);
-				break;
-
-			case ACL_TYPE_DEFAULT:
-				ext4_iset_acl(inode, &ei->i_default_acl, acl);
-				break;
+		switch (type) {
+		case ACL_TYPE_ACCESS:
+			ext4_iset_acl(inode, &ei->i_acl, acl);
+			break;
+
+		case ACL_TYPE_DEFAULT:
+			ext4_iset_acl(inode, &ei->i_default_acl, acl);
+			break;
 		}
 	}
 	return error;
@@ -299,7 +299,7 @@ ext4_check_acl(struct inode *inode, int mask)
 }
 
 int
-ext4_permission(struct inode *inode, int mask, struct nameidata *nd)
+ext4_permission(struct inode *inode, int mask)
 {
 	return generic_permission(inode, mask, ext4_check_acl);
 }
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 26a5c1abf14..cd2b855a07d 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -58,7 +58,7 @@ static inline int ext4_acl_count(size_t size)
 #define EXT4_ACL_NOT_CACHED ((void *)-1)
 
 /* acl.c */
-extern int ext4_permission (struct inode *, int, struct nameidata *);
+extern int ext4_permission (struct inode *, int);
 extern int ext4_acl_chmod (struct inode *);
 extern int ext4_init_acl (handle_t *, struct inode *, struct inode *);
 
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 495ab21b983..e9fa960ba6d 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -314,25 +314,28 @@ ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
 	if (unlikely(!bh)) {
 		ext4_error(sb, __func__,
 			    "Cannot read block bitmap - "
-			    "block_group = %d, block_bitmap = %llu",
-			    (int)block_group, (unsigned long long)bitmap_blk);
+			    "block_group = %lu, block_bitmap = %llu",
+			    block_group, bitmap_blk);
 		return NULL;
 	}
 	if (bh_uptodate_or_lock(bh))
 		return bh;
 
+	spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group));
 	if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 		ext4_init_block_bitmap(sb, bh, block_group, desc);
 		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 (bh_submit_read(bh) < 0) {
 		put_bh(bh);
 		ext4_error(sb, __func__,
 			    "Cannot read block bitmap - "
-			    "block_group = %d, block_bitmap = %llu",
-			    (int)block_group, (unsigned long long)bitmap_blk);
+			    "block_group = %lu, block_bitmap = %llu",
+			    block_group, bitmap_blk);
 		return NULL;
 	}
 	ext4_valid_block_bitmap(sb, desc, block_group, bh);
@@ -1623,6 +1626,9 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
 		free_blocks =
 			percpu_counter_sum_and_set(&sbi->s_freeblocks_counter);
 #endif
+	if (free_blocks <= root_blocks)
+		/* we don't have free space */
+		return 0;
 	if (free_blocks - root_blocks < nblocks)
 		return free_blocks - root_blocks;
 	return nblocks;
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index d3d23d73c08..ec8e33b4521 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -411,7 +411,7 @@ static int call_filldir(struct file * filp, void * dirent,
 				get_dtype(sb, fname->file_type));
 		if (error) {
 			filp->f_pos = curr_pos;
-			info->extra_fname = fname->next;
+			info->extra_fname = fname;
 			return error;
 		}
 		fname = fname->next;
@@ -450,11 +450,21 @@ static int ext4_dx_readdir(struct file * filp,
 	 * If there are any leftover names on the hash collision
 	 * chain, return them first.
 	 */
-	if (info->extra_fname &&
-	    call_filldir(filp, dirent, filldir, info->extra_fname))
-		goto finished;
+	if (info->extra_fname) {
+		if (call_filldir(filp, dirent, filldir, info->extra_fname))
+			goto finished;
 
-	if (!info->curr_node)
+		info->extra_fname = NULL;
+		info->curr_node = rb_next(info->curr_node);
+		if (!info->curr_node) {
+			if (info->next_hash == ~0) {
+				filp->f_pos = EXT4_HTREE_EOF;
+				goto finished;
+			}
+			info->curr_hash = info->next_hash;
+			info->curr_minor_hash = 0;
+		}
+	} else if (!info->curr_node)
 		info->curr_node = rb_first(&info->root);
 
 	while (1) {
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 303e41cf7b1..295003241d3 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1044,7 +1044,6 @@ extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
 
 
 /* inode.c */
-void ext4_da_release_space(struct inode *inode, int used, int to_free);
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
 		struct buffer_head *bh, ext4_fsblk_t blocknr);
 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
@@ -1073,6 +1072,8 @@ extern void ext4_set_inode_flags(struct inode *);
 extern void ext4_get_inode_flags(struct ext4_inode_info *);
 extern void ext4_set_aops(struct inode *inode);
 extern int ext4_writepage_trans_blocks(struct inode *);
+extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
+extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
 extern int ext4_block_truncate_page(handle_t *handle,
 		struct address_space *mapping, loff_t from);
 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page);
@@ -1228,6 +1229,8 @@ extern const struct inode_operations ext4_fast_symlink_inode_operations;
 /* extents.c */
 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
+extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
+				       int chunk);
 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 			ext4_lblk_t iblock,
 			unsigned long max_blocks, struct buffer_head *bh_result,
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 6c166c0a54b..d33dc56d698 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -216,7 +216,9 @@ extern int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks);
 extern ext4_fsblk_t idx_pblock(struct ext4_extent_idx *);
 extern void ext4_ext_store_pblock(struct ext4_extent *, ext4_fsblk_t);
 extern int ext4_extent_tree_init(handle_t *, struct inode *);
-extern int ext4_ext_calc_credits_for_insert(struct inode *, struct ext4_ext_path *);
+extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
+						   int num,
+						   struct ext4_ext_path *path);
 extern int ext4_ext_try_to_merge(struct inode *inode,
 				 struct ext4_ext_path *path,
 				 struct ext4_extent *);
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index eb8bc3afe6e..b455c685a98 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -51,6 +51,14 @@
 					 EXT4_XATTR_TRANS_BLOCKS - 2 + \
 					 2*EXT4_QUOTA_TRANS_BLOCKS(sb))
 
+/*
+ * Define the number of metadata blocks we need to account to modify data.
+ *
+ * This include super block, inode block, quota blocks and xattr blocks
+ */
+#define EXT4_META_TRANS_BLOCKS(sb)	(EXT4_XATTR_TRANS_BLOCKS + \
+					2*EXT4_QUOTA_TRANS_BLOCKS(sb))
+
 /* Delete operations potentially hit one directory's namespace plus an
  * entire inode, plus arbitrary amounts of bitmap/indirection data.  Be
  * generous.  We can grow the delete transaction later if necessary. */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 42c4c0c892e..b24d3c53f20 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -99,7 +99,7 @@ static int ext4_ext_journal_restart(handle_t *handle, int needed)
 	if (handle->h_buffer_credits > needed)
 		return 0;
 	err = ext4_journal_extend(handle, needed);
-	if (err)
+	if (err <= 0)
 		return err;
 	return ext4_journal_restart(handle, needed);
 }
@@ -1441,7 +1441,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
 
 	/*
 	 * get the next allocated block if the extent in the path
-	 * is before the requested block(s) 
+	 * is before the requested block(s)
 	 */
 	if (b2 < b1) {
 		b2 = ext4_ext_next_allocated_block(path);
@@ -1747,54 +1747,61 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
 }
 
 /*
- * ext4_ext_calc_credits_for_insert:
- * This routine returns max. credits that the extent tree can consume.
- * It should be OK for low-performance paths like ->writepage()
- * To allow many writing processes to fit into a single transaction,
- * the caller should calculate credits under i_data_sem and
- * pass the actual path.
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
  */
-int ext4_ext_calc_credits_for_insert(struct inode *inode,
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
 						struct ext4_ext_path *path)
 {
-	int depth, needed;
-
 	if (path) {
+		int depth = ext_depth(inode);
+		int ret = 0;
+
 		/* probably there is space in leaf? */
-		depth = ext_depth(inode);
 		if (le16_to_cpu(path[depth].p_hdr->eh_entries)
-				< le16_to_cpu(path[depth].p_hdr->eh_max))
-			return 1;
-	}
-
-	/*
-	 * given 32-bit logical block (4294967296 blocks), max. tree
-	 * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
-	 * Let's also add one more level for imbalance.
-	 */
-	depth = 5;
+				< le16_to_cpu(path[depth].p_hdr->eh_max)) {
 
-	/* allocation of new data block(s) */
-	needed = 2;
+			/*
+			 *  There are some space in the leaf tree, no
+			 *  need to account for leaf block credit
+			 *
+			 *  bitmaps and block group descriptor blocks
+			 *  and other metadat blocks still need to be
+			 *  accounted.
+			 */
+			/* 1 bitmap, 1 block group descriptor */
+			ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+		}
+	}
 
-	/*
-	 * tree can be full, so it would need to grow in depth:
-	 * we need one credit to modify old root, credits for
-	 * new root will be added in split accounting
-	 */
-	needed += 1;
+	return ext4_chunk_trans_blocks(inode, nrblocks);
+}
 
-	/*
-	 * Index split can happen, we would need:
-	 *    allocate intermediate indexes (bitmap + group)
-	 *  + change two blocks at each level, but root (already included)
-	 */
-	needed += (depth * 2) + (depth * 2);
+/*
+ * How many index/leaf blocks need to change/allocate to modify nrblocks?
+ *
+ * if nrblocks are fit in a single extent (chunk flag is 1), then
+ * in the worse case, each tree level index/leaf need to be changed
+ * if the tree split due to insert a new extent, then the old tree
+ * index/leaf need to be updated too
+ *
+ * If the nrblocks are discontiguous, they could cause
+ * the whole tree split more than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+	int index;
+	int depth = ext_depth(inode);
 
-	/* any allocation modifies superblock */
-	needed += 1;
+	if (chunk)
+		index = depth * 2;
+	else
+		index = depth * 3;
 
-	return needed;
+	return index;
 }
 
 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
@@ -1910,16 +1917,18 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 			BUG_ON(b != ex_ee_block + ex_ee_len - 1);
 		}
 
-		/* at present, extent can't cross block group: */
-		/* leaf + bitmap + group desc + sb + inode */
-		credits = 5;
+		/*
+		 * 3 for leaf, sb, and inode plus 2 (bmap and group
+		 * descriptor) for each block group; assume two block
+		 * groups plus ex_ee_len/blocks_per_block_group for
+		 * the worst case
+		 */
+		credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
 		if (ex == EXT_FIRST_EXTENT(eh)) {
 			correct_index = 1;
 			credits += (ext_depth(inode)) + 1;
 		}
-#ifdef CONFIG_QUOTA
 		credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
 
 		err = ext4_ext_journal_restart(handle, credits);
 		if (err)
@@ -2323,7 +2332,10 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 		unsigned int newdepth;
 		/* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
 		if (allocated <= EXT4_EXT_ZERO_LEN) {
-			/* Mark first half uninitialized.
+			/*
+			 * iblock == ee_block is handled by the zerouout
+			 * at the beginning.
+			 * Mark first half uninitialized.
 			 * Mark second half initialized and zero out the
 			 * initialized extent
 			 */
@@ -2346,7 +2358,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 				ex->ee_len   = orig_ex.ee_len;
 				ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
 				ext4_ext_dirty(handle, inode, path + depth);
-				/* zeroed the full extent */
+				/* blocks available from iblock */
 				return allocated;
 
 			} else if (err)
@@ -2374,6 +2386,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 					err = PTR_ERR(path);
 					return err;
 				}
+				/* get the second half extent details */
 				ex = path[depth].p_ext;
 				err = ext4_ext_get_access(handle, inode,
 								path + depth);
@@ -2403,6 +2416,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 			ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
 			ext4_ext_dirty(handle, inode, path + depth);
 			/* zeroed the full extent */
+			/* blocks available from iblock */
 			return allocated;
 
 		} else if (err)
@@ -2418,23 +2432,22 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 		 */
 		orig_ex.ee_len = cpu_to_le16(ee_len -
 						ext4_ext_get_actual_len(ex3));
-		if (newdepth != depth) {
-			depth = newdepth;
-			ext4_ext_drop_refs(path);
-			path = ext4_ext_find_extent(inode, iblock, path);
-			if (IS_ERR(path)) {
-				err = PTR_ERR(path);
-				goto out;
-			}
-			eh = path[depth].p_hdr;
-			ex = path[depth].p_ext;
-			if (ex2 != &newex)
-				ex2 = ex;
-
-			err = ext4_ext_get_access(handle, inode, path + depth);
-			if (err)
-				goto out;
+		depth = newdepth;
+		ext4_ext_drop_refs(path);
+		path = ext4_ext_find_extent(inode, iblock, path);
+		if (IS_ERR(path)) {
+			err = PTR_ERR(path);
+			goto out;
 		}
+		eh = path[depth].p_hdr;
+		ex = path[depth].p_ext;
+		if (ex2 != &newex)
+			ex2 = ex;
+
+		err = ext4_ext_get_access(handle, inode, path + depth);
+		if (err)
+			goto out;
+
 		allocated = max_blocks;
 
 		/* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
@@ -2452,6 +2465,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 			ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
 			ext4_ext_dirty(handle, inode, path + depth);
 			/* zero out the first half */
+			/* blocks available from iblock */
 			return allocated;
 		}
 	}
@@ -2796,7 +2810,7 @@ void ext4_ext_truncate(struct inode *inode)
 	/*
 	 * probably first extent we're gonna free will be last in block
 	 */
-	err = ext4_writepage_trans_blocks(inode) + 3;
+	err = ext4_writepage_trans_blocks(inode);
 	handle = ext4_journal_start(inode, err);
 	if (IS_ERR(handle))
 		return;
@@ -2810,7 +2824,7 @@ void ext4_ext_truncate(struct inode *inode)
 	down_write(&EXT4_I(inode)->i_data_sem);
 	ext4_ext_invalidate_cache(inode);
 
-	ext4_mb_discard_inode_preallocations(inode);
+	ext4_discard_reservation(inode);
 
 	/*
 	 * TODO: optimization is possible here.
@@ -2849,27 +2863,6 @@ out_stop:
 	ext4_journal_stop(handle);
 }
 
-/*
- * ext4_ext_writepage_trans_blocks:
- * calculate max number of blocks we could modify
- * in order to allocate new block for an inode
- */
-int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
-{
-	int needed;
-
-	needed = ext4_ext_calc_credits_for_insert(inode, NULL);
-
-	/* caller wants to allocate num blocks, but note it includes sb */
-	needed = needed * num - (num - 1);
-
-#ifdef CONFIG_QUOTA
-	needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
-
-	return needed;
-}
-
 static void ext4_falloc_update_inode(struct inode *inode,
 				int mode, loff_t new_size, int update_ctime)
 {
@@ -2930,10 +2923,9 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
 	max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
 							- block;
 	/*
-	 * credits to insert 1 extent into extent tree + buffers to be able to
-	 * modify 1 super block, 1 block bitmap and 1 group descriptor.
+	 * credits to insert 1 extent into extent tree
 	 */
-	credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
+	credits = ext4_chunk_trans_blocks(inode, max_blocks);
 	mutex_lock(&inode->i_mutex);
 retry:
 	while (ret >= 0 && ret < max_blocks) {
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index a92eb305344..f344834bbf5 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -97,34 +97,44 @@ unsigned ext4_init_inode_bitmap(struct super_block *sb, struct buffer_head *bh,
  * Return buffer_head of bitmap on success or NULL.
  */
 static struct buffer_head *
-read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
+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)
-		goto error_out;
-	if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
-		bh = sb_getblk(sb, ext4_inode_bitmap(sb, desc));
-		if (!buffer_uptodate(bh)) {
-			lock_buffer(bh);
-			if (!buffer_uptodate(bh)) {
-				ext4_init_inode_bitmap(sb, bh, block_group,
-						       desc);
-				set_buffer_uptodate(bh);
-			}
-			unlock_buffer(bh);
-		}
-	} else {
-		bh = sb_bread(sb, ext4_inode_bitmap(sb, 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 (!bh)
-		ext4_error(sb, "read_inode_bitmap",
+	if (bh_uptodate_or_lock(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_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 (bh_submit_read(bh) < 0) {
+		put_bh(bh);
+		ext4_error(sb, __func__,
 			    "Cannot read inode bitmap - "
 			    "block_group = %lu, inode_bitmap = %llu",
-			    block_group, ext4_inode_bitmap(sb, desc));
-error_out:
+			    block_group, bitmap_blk);
+		return NULL;
+	}
 	return bh;
 }
 
@@ -200,7 +210,7 @@ void ext4_free_inode (handle_t *handle, struct inode * inode)
 	}
 	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
-	bitmap_bh = read_inode_bitmap(sb, block_group);
+	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 	if (!bitmap_bh)
 		goto error_return;
 
@@ -341,7 +351,7 @@ find_close_to_parent:
 			goto found_flexbg;
 		}
 
-		if (best_flex < 0 ||
+		if (flex_group[best_flex].free_inodes == 0 ||
 		    (flex_group[i].free_blocks >
 		     flex_group[best_flex].free_blocks &&
 		     flex_group[i].free_inodes))
@@ -623,7 +633,7 @@ got_group:
 			goto fail;
 
 		brelse(bitmap_bh);
-		bitmap_bh = read_inode_bitmap(sb, group);
+		bitmap_bh = ext4_read_inode_bitmap(sb, group);
 		if (!bitmap_bh)
 			goto fail;
 
@@ -728,7 +738,7 @@ got:
 
 			/* When marking the block group with
 			 * ~EXT4_BG_INODE_UNINIT we don't want to depend
-			 * on the value of bg_itable_unsed even though
+			 * on the value of bg_itable_unused even though
 			 * mke2fs could have initialized the same for us.
 			 * Instead we calculated the value below
 			 */
@@ -891,7 +901,7 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 
 	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
-	bitmap_bh = read_inode_bitmap(sb, block_group);
+	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 	if (!bitmap_bh) {
 		ext4_warning(sb, __func__,
 			     "inode bitmap error for orphan %lu", ino);
@@ -969,7 +979,7 @@ unsigned long ext4_count_free_inodes (struct super_block * sb)
 			continue;
 		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 		brelse(bitmap_bh);
-		bitmap_bh = read_inode_bitmap(sb, i);
+		bitmap_bh = ext4_read_inode_bitmap(sb, i);
 		if (!bitmap_bh)
 			continue;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8ca2763df09..7e91913e325 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -41,6 +41,8 @@
 #include "acl.h"
 #include "ext4_extents.h"
 
+#define MPAGE_DA_EXTENT_TAIL 0x01
+
 static inline int ext4_begin_ordered_truncate(struct inode *inode,
 					      loff_t new_size)
 {
@@ -191,6 +193,7 @@ static int ext4_journal_test_restart(handle_t *handle, struct inode *inode)
 void ext4_delete_inode (struct inode * inode)
 {
 	handle_t *handle;
+	int err;
 
 	if (ext4_should_order_data(inode))
 		ext4_begin_ordered_truncate(inode, 0);
@@ -199,8 +202,9 @@ void ext4_delete_inode (struct inode * inode)
 	if (is_bad_inode(inode))
 		goto no_delete;
 
-	handle = start_transaction(inode);
+	handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
 	if (IS_ERR(handle)) {
+		ext4_std_error(inode->i_sb, PTR_ERR(handle));
 		/*
 		 * If we're going to skip the normal cleanup, we still need to
 		 * make sure that the in-core orphan linked list is properly
@@ -213,8 +217,34 @@ void ext4_delete_inode (struct inode * inode)
 	if (IS_SYNC(inode))
 		handle->h_sync = 1;
 	inode->i_size = 0;
+	err = ext4_mark_inode_dirty(handle, inode);
+	if (err) {
+		ext4_warning(inode->i_sb, __func__,
+			     "couldn't mark inode dirty (err %d)", err);
+		goto stop_handle;
+	}
 	if (inode->i_blocks)
 		ext4_truncate(inode);
+
+	/*
+	 * ext4_ext_truncate() doesn't reserve any slop when it
+	 * restarts journal transactions; therefore there may not be
+	 * enough credits left in the handle to remove the inode from
+	 * the orphan list and set the dtime field.
+	 */
+	if (handle->h_buffer_credits < 3) {
+		err = ext4_journal_extend(handle, 3);
+		if (err > 0)
+			err = ext4_journal_restart(handle, 3);
+		if (err != 0) {
+			ext4_warning(inode->i_sb, __func__,
+				     "couldn't extend journal (err %d)", err);
+		stop_handle:
+			ext4_journal_stop(handle);
+			goto no_delete;
+		}
+	}
+
 	/*
 	 * Kill off the orphan record which ext4_truncate created.
 	 * AKPM: I think this can be inside the above `if'.
@@ -952,23 +982,74 @@ out:
 	return err;
 }
 
-/* Maximum number of blocks we map for direct IO at once. */
-#define DIO_MAX_BLOCKS 4096
 /*
- * Number of credits we need for writing DIO_MAX_BLOCKS:
- * We need sb + group descriptor + bitmap + inode -> 4
- * For B blocks with A block pointers per block we need:
- * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
- * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate @blocks for non extent file based file
  */
-#define DIO_CREDITS 25
+static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+{
+	int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+	int ind_blks, dind_blks, tind_blks;
+
+	/* number of new indirect blocks needed */
+	ind_blks = (blocks + icap - 1) / icap;
+
+	dind_blks = (ind_blks + icap - 1) / icap;
 
+	tind_blks = 1;
+
+	return ind_blks + dind_blks + tind_blks;
+}
 
 /*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate given number of blocks
+ */
+static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+{
+	if (!blocks)
+		return 0;
+
+	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
+		return ext4_ext_calc_metadata_amount(inode, blocks);
+
+	return ext4_indirect_calc_metadata_amount(inode, blocks);
+}
+
+static void ext4_da_update_reserve_space(struct inode *inode, int used)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	int total, mdb, mdb_free;
+
+	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+	/* recalculate the number of metablocks still need to be reserved */
+	total = EXT4_I(inode)->i_reserved_data_blocks - used;
+	mdb = ext4_calc_metadata_amount(inode, total);
+
+	/* figure out how many metablocks to release */
+	BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+	mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
+
+	/* Account for allocated meta_blocks */
+	mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+
+	/* update fs free blocks counter for truncate case */
+	percpu_counter_add(&sbi->s_freeblocks_counter, mdb_free);
+
+	/* update per-inode reservations */
+	BUG_ON(used  > EXT4_I(inode)->i_reserved_data_blocks);
+	EXT4_I(inode)->i_reserved_data_blocks -= used;
+
+	BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+	EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+	EXT4_I(inode)->i_allocated_meta_blocks = 0;
+	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+}
+
+/*
+ * The ext4_get_blocks_wrap() function try to look up the requested blocks,
+ * and returns if the blocks are already mapped.
  *
- *
- * ext4_ext4 get_block() wrapper function
- * It will do a look up first, and returns if the blocks already mapped.
  * Otherwise it takes the write lock of the i_data_sem and allocate blocks
  * and store the allocated blocks in the result buffer head and mark it
  * mapped.
@@ -1069,26 +1150,30 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 		 * which were deferred till now
 		 */
 		if ((retval > 0) && buffer_delay(bh))
-			ext4_da_release_space(inode, retval, 0);
+			ext4_da_update_reserve_space(inode, retval);
 	}
 
 	up_write((&EXT4_I(inode)->i_data_sem));
 	return retval;
 }
 
+/* Maximum number of blocks we map for direct IO at once. */
+#define DIO_MAX_BLOCKS 4096
+
 static int ext4_get_block(struct inode *inode, sector_t iblock,
 			struct buffer_head *bh_result, int create)
 {
 	handle_t *handle = ext4_journal_current_handle();
 	int ret = 0, started = 0;
 	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+	int dio_credits;
 
 	if (create && !handle) {
 		/* Direct IO write... */
 		if (max_blocks > DIO_MAX_BLOCKS)
 			max_blocks = DIO_MAX_BLOCKS;
-		handle = ext4_journal_start(inode, DIO_CREDITS +
-			      2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb));
+		dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
+		handle = ext4_journal_start(inode, dio_credits);
 		if (IS_ERR(handle)) {
 			ret = PTR_ERR(handle);
 			goto out;
@@ -1336,12 +1421,8 @@ static int ext4_ordered_write_end(struct file *file,
 {
 	handle_t *handle = ext4_journal_current_handle();
 	struct inode *inode = mapping->host;
-	unsigned from, to;
 	int ret = 0, ret2;
 
-	from = pos & (PAGE_CACHE_SIZE - 1);
-	to = from + len;
-
 	ret = ext4_jbd2_file_inode(handle, inode);
 
 	if (ret == 0) {
@@ -1437,36 +1518,6 @@ static int ext4_journalled_write_end(struct file *file,
 
 	return ret ? ret : copied;
 }
-/*
- * Calculate the number of metadata blocks need to reserve
- * to allocate @blocks for non extent file based file
- */
-static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
-{
-	int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
-	int ind_blks, dind_blks, tind_blks;
-
-	/* number of new indirect blocks needed */
-	ind_blks = (blocks + icap - 1) / icap;
-
-	dind_blks = (ind_blks + icap - 1) / icap;
-
-	tind_blks = 1;
-
-	return ind_blks + dind_blks + tind_blks;
-}
-
-/*
- * Calculate the number of metadata blocks need to reserve
- * to allocate given number of blocks
- */
-static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
-{
-	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-		return ext4_ext_calc_metadata_amount(inode, blocks);
-
-	return ext4_indirect_calc_metadata_amount(inode, blocks);
-}
 
 static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
 {
@@ -1490,7 +1541,6 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
 		spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 		return -ENOSPC;
 	}
-
 	/* reduce fs free blocks counter */
 	percpu_counter_sub(&sbi->s_freeblocks_counter, total);
 
@@ -1501,35 +1551,49 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
 	return 0;       /* success */
 }
 
-void ext4_da_release_space(struct inode *inode, int used, int to_free)
+static void ext4_da_release_space(struct inode *inode, int to_free)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	int total, mdb, mdb_free, release;
 
+	if (!to_free)
+		return;		/* Nothing to release, exit */
+
 	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+
+	if (!EXT4_I(inode)->i_reserved_data_blocks) {
+		/*
+		 * if there is no reserved blocks, but we try to free some
+		 * then the counter is messed up somewhere.
+		 * but since this function is called from invalidate
+		 * page, it's harmless to return without any action
+		 */
+		printk(KERN_INFO "ext4 delalloc try to release %d reserved "
+			    "blocks for inode %lu, but there is no reserved "
+			    "data blocks\n", to_free, inode->i_ino);
+		spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+		return;
+	}
+
 	/* recalculate the number of metablocks still need to be reserved */
-	total = EXT4_I(inode)->i_reserved_data_blocks - used - to_free;
+	total = EXT4_I(inode)->i_reserved_data_blocks - to_free;
 	mdb = ext4_calc_metadata_amount(inode, total);
 
 	/* figure out how many metablocks to release */
 	BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
 	mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
 
-	/* Account for allocated meta_blocks */
-	mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
-
 	release = to_free + mdb_free;
 
 	/* update fs free blocks counter for truncate case */
 	percpu_counter_add(&sbi->s_freeblocks_counter, release);
 
 	/* update per-inode reservations */
-	BUG_ON(used + to_free > EXT4_I(inode)->i_reserved_data_blocks);
-	EXT4_I(inode)->i_reserved_data_blocks -= (used + to_free);
+	BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
+	EXT4_I(inode)->i_reserved_data_blocks -= to_free;
 
 	BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
 	EXT4_I(inode)->i_reserved_meta_blocks = mdb;
-	EXT4_I(inode)->i_allocated_meta_blocks = 0;
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 }
 
@@ -1551,7 +1615,7 @@ static void ext4_da_page_release_reservation(struct page *page,
 		}
 		curr_off = next_off;
 	} while ((bh = bh->b_this_page) != head);
-	ext4_da_release_space(page->mapping->host, 0, to_release);
+	ext4_da_release_space(page->mapping->host, to_release);
 }
 
 /*
@@ -1564,11 +1628,13 @@ struct mpage_da_data {
 	unsigned long first_page, next_page;	/* extent of pages */
 	get_block_t *get_block;
 	struct writeback_control *wbc;
+	int io_done;
+	long pages_written;
 };
 
 /*
  * mpage_da_submit_io - walks through extent of pages and try to write
- * them with __mpage_writepage()
+ * them with writepage() call back
  *
  * @mpd->inode: inode
  * @mpd->first_page: first page of the extent
@@ -1583,18 +1649,11 @@ struct mpage_da_data {
 static int mpage_da_submit_io(struct mpage_da_data *mpd)
 {
 	struct address_space *mapping = mpd->inode->i_mapping;
-	struct mpage_data mpd_pp = {
-		.bio = NULL,
-		.last_block_in_bio = 0,
-		.get_block = mpd->get_block,
-		.use_writepage = 1,
-	};
 	int ret = 0, err, nr_pages, i;
 	unsigned long index, end;
 	struct pagevec pvec;
 
 	BUG_ON(mpd->next_page <= mpd->first_page);
-
 	pagevec_init(&pvec, 0);
 	index = mpd->first_page;
 	end = mpd->next_page - 1;
@@ -1612,8 +1671,9 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
 				break;
 			index++;
 
-			err = __mpage_writepage(page, mpd->wbc, &mpd_pp);
-
+			err = mapping->a_ops->writepage(page, mpd->wbc);
+			if (!err)
+				mpd->pages_written++;
 			/*
 			 * In error case, we have to continue because
 			 * remaining pages are still locked
@@ -1624,9 +1684,6 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
 		}
 		pagevec_release(&pvec);
 	}
-	if (mpd_pp.bio)
-		mpage_bio_submit(WRITE, mpd_pp.bio);
-
 	return ret;
 }
 
@@ -1649,7 +1706,7 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
 	int blocks = exbh->b_size >> inode->i_blkbits;
 	sector_t pblock = exbh->b_blocknr, cur_logical;
 	struct buffer_head *head, *bh;
-	unsigned long index, end;
+	pgoff_t index, end;
 	struct pagevec pvec;
 	int nr_pages, i;
 
@@ -1692,6 +1749,13 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
 				if (buffer_delay(bh)) {
 					bh->b_blocknr = pblock;
 					clear_buffer_delay(bh);
+					bh->b_bdev = inode->i_sb->s_bdev;
+				} else if (buffer_unwritten(bh)) {
+					bh->b_blocknr = pblock;
+					clear_buffer_unwritten(bh);
+					set_buffer_mapped(bh);
+					set_buffer_new(bh);
+					bh->b_bdev = inode->i_sb->s_bdev;
 				} else if (buffer_mapped(bh))
 					BUG_ON(bh->b_blocknr != pblock);
 
@@ -1727,13 +1791,11 @@ static inline void __unmap_underlying_blocks(struct inode *inode,
  *
  * The function skips space we know is already mapped to disk blocks.
  *
- * The function ignores errors ->get_block() returns, thus real
- * error handling is postponed to __mpage_writepage()
  */
 static void mpage_da_map_blocks(struct mpage_da_data *mpd)
 {
+	int err = 0;
 	struct buffer_head *lbh = &mpd->lbh;
-	int err = 0, remain = lbh->b_size;
 	sector_t next = lbh->b_blocknr;
 	struct buffer_head new;
 
@@ -1743,38 +1805,36 @@ static void mpage_da_map_blocks(struct mpage_da_data *mpd)
 	if (buffer_mapped(lbh) && !buffer_delay(lbh))
 		return;
 
-	while (remain) {
-		new.b_state = lbh->b_state;
-		new.b_blocknr = 0;
-		new.b_size = remain;
-		err = mpd->get_block(mpd->inode, next, &new, 1);
-		if (err) {
-			/*
-			 * Rather than implement own error handling
-			 * here, we just leave remaining blocks
-			 * unallocated and try again with ->writepage()
-			 */
-			break;
-		}
-		BUG_ON(new.b_size == 0);
+	new.b_state = lbh->b_state;
+	new.b_blocknr = 0;
+	new.b_size = lbh->b_size;
 
-		if (buffer_new(&new))
-			__unmap_underlying_blocks(mpd->inode, &new);
+	/*
+	 * If we didn't accumulate anything
+	 * to write simply return
+	 */
+	if (!new.b_size)
+		return;
+	err = mpd->get_block(mpd->inode, next, &new, 1);
+	if (err)
+		return;
+	BUG_ON(new.b_size == 0);
 
-		/*
-		 * If blocks are delayed marked, we need to
-		 * put actual blocknr and drop delayed bit
-		 */
-		if (buffer_delay(lbh))
-			mpage_put_bnr_to_bhs(mpd, next, &new);
+	if (buffer_new(&new))
+		__unmap_underlying_blocks(mpd->inode, &new);
 
-		/* go for the remaining blocks */
-		next += new.b_size >> mpd->inode->i_blkbits;
-		remain -= new.b_size;
-	}
+	/*
+	 * If blocks are delayed marked, we need to
+	 * put actual blocknr and drop delayed bit
+	 */
+	if (buffer_delay(lbh) || buffer_unwritten(lbh))
+		mpage_put_bnr_to_bhs(mpd, next, &new);
+
+	return;
 }
 
-#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | (1 << BH_Delay))
+#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
+		(1 << BH_Delay) | (1 << BH_Unwritten))
 
 /*
  * mpage_add_bh_to_extent - try to add one more block to extent of blocks
@@ -1788,41 +1848,61 @@ static void mpage_da_map_blocks(struct mpage_da_data *mpd)
 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
 				   sector_t logical, struct buffer_head *bh)
 {
-	struct buffer_head *lbh = &mpd->lbh;
 	sector_t next;
+	size_t b_size = bh->b_size;
+	struct buffer_head *lbh = &mpd->lbh;
+	int nrblocks = lbh->b_size >> mpd->inode->i_blkbits;
 
-	next = lbh->b_blocknr + (lbh->b_size >> mpd->inode->i_blkbits);
-
+	/* check if thereserved journal credits might overflow */
+	if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) {
+		if (nrblocks >= EXT4_MAX_TRANS_DATA) {
+			/*
+			 * With non-extent format we are limited by the journal
+			 * credit available.  Total credit needed to insert
+			 * nrblocks contiguous blocks is dependent on the
+			 * nrblocks.  So limit nrblocks.
+			 */
+			goto flush_it;
+		} else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
+				EXT4_MAX_TRANS_DATA) {
+			/*
+			 * Adding the new buffer_head would make it cross the
+			 * allowed limit for which we have journal credit
+			 * reserved. So limit the new bh->b_size
+			 */
+			b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
+						mpd->inode->i_blkbits;
+			/* we will do mpage_da_submit_io in the next loop */
+		}
+	}
 	/*
 	 * First block in the extent
 	 */
 	if (lbh->b_size == 0) {
 		lbh->b_blocknr = logical;
-		lbh->b_size = bh->b_size;
+		lbh->b_size = b_size;
 		lbh->b_state = bh->b_state & BH_FLAGS;
 		return;
 	}
 
+	next = lbh->b_blocknr + nrblocks;
 	/*
 	 * Can we merge the block to our big extent?
 	 */
 	if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) {
-		lbh->b_size += bh->b_size;
+		lbh->b_size += b_size;
 		return;
 	}
 
+flush_it:
 	/*
 	 * We couldn't merge the block to our extent, so we
 	 * need to flush current  extent and start new one
 	 */
 	mpage_da_map_blocks(mpd);
-
-	/*
-	 * Now start a new extent
-	 */
-	lbh->b_size = bh->b_size;
-	lbh->b_state = bh->b_state & BH_FLAGS;
-	lbh->b_blocknr = logical;
+	mpage_da_submit_io(mpd);
+	mpd->io_done = 1;
+	return;
 }
 
 /*
@@ -1842,17 +1922,35 @@ static int __mpage_da_writepage(struct page *page,
 	struct buffer_head *bh, *head, fake;
 	sector_t logical;
 
+	if (mpd->io_done) {
+		/*
+		 * Rest of the page in the page_vec
+		 * redirty then and skip then. We will
+		 * try to to write them again after
+		 * starting a new transaction
+		 */
+		redirty_page_for_writepage(wbc, page);
+		unlock_page(page);
+		return MPAGE_DA_EXTENT_TAIL;
+	}
 	/*
 	 * Can we merge this page to current extent?
 	 */
 	if (mpd->next_page != page->index) {
 		/*
 		 * Nope, we can't. So, we map non-allocated blocks
-		 * and start IO on them using __mpage_writepage()
+		 * and start IO on them using writepage()
 		 */
 		if (mpd->next_page != mpd->first_page) {
 			mpage_da_map_blocks(mpd);
 			mpage_da_submit_io(mpd);
+			/*
+			 * skip rest of the page in the page_vec
+			 */
+			mpd->io_done = 1;
+			redirty_page_for_writepage(wbc, page);
+			unlock_page(page);
+			return MPAGE_DA_EXTENT_TAIL;
 		}
 
 		/*
@@ -1883,6 +1981,8 @@ static int __mpage_da_writepage(struct page *page,
 		set_buffer_dirty(bh);
 		set_buffer_uptodate(bh);
 		mpage_add_bh_to_extent(mpd, logical, bh);
+		if (mpd->io_done)
+			return MPAGE_DA_EXTENT_TAIL;
 	} else {
 		/*
 		 * Page with regular buffer heads, just add all dirty ones
@@ -1891,8 +1991,12 @@ static int __mpage_da_writepage(struct page *page,
 		bh = head;
 		do {
 			BUG_ON(buffer_locked(bh));
-			if (buffer_dirty(bh))
+			if (buffer_dirty(bh) &&
+				(!buffer_mapped(bh) || buffer_delay(bh))) {
 				mpage_add_bh_to_extent(mpd, logical, bh);
+				if (mpd->io_done)
+					return MPAGE_DA_EXTENT_TAIL;
+			}
 			logical++;
 		} while ((bh = bh->b_this_page) != head);
 	}
@@ -1911,22 +2015,13 @@ static int __mpage_da_writepage(struct page *page,
  *
  * This is a library function, which implements the writepages()
  * address_space_operation.
- *
- * In order to avoid duplication of logic that deals with partial pages,
- * multiple bio per page, etc, we find non-allocated blocks, allocate
- * them with minimal calls to ->get_block() and re-use __mpage_writepage()
- *
- * It's important that we call __mpage_writepage() only once for each
- * involved page, otherwise we'd have to implement more complicated logic
- * to deal with pages w/o PG_lock or w/ PG_writeback and so on.
- *
- * See comments to mpage_writepages()
  */
 static int mpage_da_writepages(struct address_space *mapping,
 			       struct writeback_control *wbc,
 			       get_block_t get_block)
 {
 	struct mpage_da_data mpd;
+	long to_write;
 	int ret;
 
 	if (!get_block)
@@ -1940,17 +2035,22 @@ static int mpage_da_writepages(struct address_space *mapping,
 	mpd.first_page = 0;
 	mpd.next_page = 0;
 	mpd.get_block = get_block;
+	mpd.io_done = 0;
+	mpd.pages_written = 0;
+
+	to_write = wbc->nr_to_write;
 
 	ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, &mpd);
 
 	/*
 	 * Handle last extent of pages
 	 */
-	if (mpd.next_page != mpd.first_page) {
+	if (!mpd.io_done && mpd.next_page != mpd.first_page) {
 		mpage_da_map_blocks(&mpd);
 		mpage_da_submit_io(&mpd);
 	}
 
+	wbc->nr_to_write = to_write - mpd.pages_written;
 	return ret;
 }
 
@@ -2155,63 +2255,95 @@ static int ext4_da_writepage(struct page *page,
 }
 
 /*
- * For now just follow the DIO way to estimate the max credits
- * needed to write out EXT4_MAX_WRITEBACK_PAGES.
- * todo: need to calculate the max credits need for
- * extent based files, currently the DIO credits is based on
- * indirect-blocks mapping way.
- *
- * Probably should have a generic way to calculate credits
- * for DIO, writepages, and truncate
+ * This is called via ext4_da_writepages() to
+ * calulate the total number of credits to reserve to fit
+ * a single extent allocation into a single transaction,
+ * ext4_da_writpeages() will loop calling this before
+ * the block allocation.
  */
-#define EXT4_MAX_WRITEBACK_PAGES      DIO_MAX_BLOCKS
-#define EXT4_MAX_WRITEBACK_CREDITS    DIO_CREDITS
+
+static int ext4_da_writepages_trans_blocks(struct inode *inode)
+{
+	int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
+
+	/*
+	 * With non-extent format the journal credit needed to
+	 * insert nrblocks contiguous block is dependent on
+	 * number of contiguous block. So we will limit
+	 * number of contiguous block to a sane value
+	 */
+	if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
+	    (max_blocks > EXT4_MAX_TRANS_DATA))
+		max_blocks = EXT4_MAX_TRANS_DATA;
+
+	return ext4_chunk_trans_blocks(inode, max_blocks);
+}
 
 static int ext4_da_writepages(struct address_space *mapping,
-				struct writeback_control *wbc)
+			      struct writeback_control *wbc)
 {
-	struct inode *inode = mapping->host;
 	handle_t *handle = NULL;
-	int needed_blocks;
-	int ret = 0;
-	long to_write;
 	loff_t range_start = 0;
+	struct inode *inode = mapping->host;
+	int needed_blocks, ret = 0, nr_to_writebump = 0;
+	long to_write, pages_skipped = 0;
+	struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
 
 	/*
 	 * No pages to write? This is mainly a kludge to avoid starting
 	 * a transaction for special inodes like journal inode on last iput()
 	 * because that could violate lock ordering on umount
 	 */
-	if (!mapping->nrpages)
+	if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
 		return 0;
-
 	/*
-	 * Estimate the worse case needed credits to write out
-	 * EXT4_MAX_BUF_BLOCKS pages
+	 * Make sure nr_to_write is >= sbi->s_mb_stream_request
+	 * This make sure small files blocks are allocated in
+	 * single attempt. This ensure that small files
+	 * get less fragmented.
 	 */
-	needed_blocks = EXT4_MAX_WRITEBACK_CREDITS;
+	if (wbc->nr_to_write < sbi->s_mb_stream_request) {
+		nr_to_writebump = sbi->s_mb_stream_request - wbc->nr_to_write;
+		wbc->nr_to_write = sbi->s_mb_stream_request;
+	}
 
-	to_write = wbc->nr_to_write;
-	if (!wbc->range_cyclic) {
+	if (!wbc->range_cyclic)
 		/*
 		 * If range_cyclic is not set force range_cont
 		 * and save the old writeback_index
 		 */
 		wbc->range_cont = 1;
-		range_start =  wbc->range_start;
-	}
 
-	while (!ret && to_write) {
+	range_start =  wbc->range_start;
+	pages_skipped = wbc->pages_skipped;
+
+restart_loop:
+	to_write = wbc->nr_to_write;
+	while (!ret && to_write > 0) {
+
+		/*
+		 * we  insert one extent at a time. So we need
+		 * credit needed for single extent allocation.
+		 * journalled mode is currently not supported
+		 * by delalloc
+		 */
+		BUG_ON(ext4_should_journal_data(inode));
+		needed_blocks = ext4_da_writepages_trans_blocks(inode);
+
 		/* start a new transaction*/
 		handle = ext4_journal_start(inode, needed_blocks);
 		if (IS_ERR(handle)) {
 			ret = PTR_ERR(handle);
+			printk(KERN_EMERG "%s: jbd2_start: "
+			       "%ld pages, ino %lu; err %d\n", __func__,
+				wbc->nr_to_write, inode->i_ino, ret);
+			dump_stack();
 			goto out_writepages;
 		}
 		if (ext4_should_order_data(inode)) {
 			/*
 			 * With ordered mode we need to add
-			 * the inode to the journal handle
+			 * the inode to the journal handl
 			 * when we do block allocation.
 			 */
 			ret = ext4_jbd2_file_inode(handle, inode);
@@ -2219,20 +2351,20 @@ static int ext4_da_writepages(struct address_space *mapping,
 				ext4_journal_stop(handle);
 				goto out_writepages;
 			}
-
 		}
-		/*
-		 * set the max dirty pages could be write at a time
-		 * to fit into the reserved transaction credits
-		 */
-		if (wbc->nr_to_write > EXT4_MAX_WRITEBACK_PAGES)
-			wbc->nr_to_write = EXT4_MAX_WRITEBACK_PAGES;
 
 		to_write -= wbc->nr_to_write;
 		ret = mpage_da_writepages(mapping, wbc,
-						ext4_da_get_block_write);
+					  ext4_da_get_block_write);
 		ext4_journal_stop(handle);
-		if (wbc->nr_to_write) {
+		if (ret == MPAGE_DA_EXTENT_TAIL) {
+			/*
+			 * got one extent now try with
+			 * rest of the pages
+			 */
+			to_write += wbc->nr_to_write;
+			ret = 0;
+		} else if (wbc->nr_to_write) {
 			/*
 			 * There is no more writeout needed
 			 * or we requested for a noblocking writeout
@@ -2244,10 +2376,18 @@ static int ext4_da_writepages(struct address_space *mapping,
 		wbc->nr_to_write = to_write;
 	}
 
-out_writepages:
-	wbc->nr_to_write = to_write;
-	if (range_start)
+	if (wbc->range_cont && (pages_skipped != wbc->pages_skipped)) {
+		/* We skipped pages in this loop */
 		wbc->range_start = range_start;
+		wbc->nr_to_write = to_write +
+				wbc->pages_skipped - pages_skipped;
+		wbc->pages_skipped = pages_skipped;
+		goto restart_loop;
+	}
+
+out_writepages:
+	wbc->nr_to_write = to_write - nr_to_writebump;
+	wbc->range_start = range_start;
 	return ret;
 }
 
@@ -2280,8 +2420,11 @@ retry:
 	}
 
 	page = __grab_cache_page(mapping, index);
-	if (!page)
-		return -ENOMEM;
+	if (!page) {
+		ext4_journal_stop(handle);
+		ret = -ENOMEM;
+		goto out;
+	}
 	*pagep = page;
 
 	ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
@@ -2806,59 +2949,63 @@ static int ext4_journalled_set_page_dirty(struct page *page)
 }
 
 static const struct address_space_operations ext4_ordered_aops = {
-	.readpage	= ext4_readpage,
-	.readpages	= ext4_readpages,
-	.writepage	= ext4_normal_writepage,
-	.sync_page	= block_sync_page,
-	.write_begin	= ext4_write_begin,
-	.write_end	= ext4_ordered_write_end,
-	.bmap		= ext4_bmap,
-	.invalidatepage	= ext4_invalidatepage,
-	.releasepage	= ext4_releasepage,
-	.direct_IO	= ext4_direct_IO,
-	.migratepage	= buffer_migrate_page,
+	.readpage		= ext4_readpage,
+	.readpages		= ext4_readpages,
+	.writepage		= ext4_normal_writepage,
+	.sync_page		= block_sync_page,
+	.write_begin		= ext4_write_begin,
+	.write_end		= ext4_ordered_write_end,
+	.bmap			= ext4_bmap,
+	.invalidatepage		= ext4_invalidatepage,
+	.releasepage		= ext4_releasepage,
+	.direct_IO		= ext4_direct_IO,
+	.migratepage		= buffer_migrate_page,
+	.is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext4_writeback_aops = {
-	.readpage	= ext4_readpage,
-	.readpages	= ext4_readpages,
-	.writepage	= ext4_normal_writepage,
-	.sync_page	= block_sync_page,
-	.write_begin	= ext4_write_begin,
-	.write_end	= ext4_writeback_write_end,
-	.bmap		= ext4_bmap,
-	.invalidatepage	= ext4_invalidatepage,
-	.releasepage	= ext4_releasepage,
-	.direct_IO	= ext4_direct_IO,
-	.migratepage	= buffer_migrate_page,
+	.readpage		= ext4_readpage,
+	.readpages		= ext4_readpages,
+	.writepage		= ext4_normal_writepage,
+	.sync_page		= block_sync_page,
+	.write_begin		= ext4_write_begin,
+	.write_end		= ext4_writeback_write_end,
+	.bmap			= ext4_bmap,
+	.invalidatepage		= ext4_invalidatepage,
+	.releasepage		= ext4_releasepage,
+	.direct_IO		= ext4_direct_IO,
+	.migratepage		= buffer_migrate_page,
+	.is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext4_journalled_aops = {
-	.readpage	= ext4_readpage,
-	.readpages	= ext4_readpages,
-	.writepage	= ext4_journalled_writepage,
-	.sync_page	= block_sync_page,
-	.write_begin	= ext4_write_begin,
-	.write_end	= ext4_journalled_write_end,
-	.set_page_dirty	= ext4_journalled_set_page_dirty,
-	.bmap		= ext4_bmap,
-	.invalidatepage	= ext4_invalidatepage,
-	.releasepage	= ext4_releasepage,
+	.readpage		= ext4_readpage,
+	.readpages		= ext4_readpages,
+	.writepage		= ext4_journalled_writepage,
+	.sync_page		= block_sync_page,
+	.write_begin		= ext4_write_begin,
+	.write_end		= ext4_journalled_write_end,
+	.set_page_dirty		= ext4_journalled_set_page_dirty,
+	.bmap			= ext4_bmap,
+	.invalidatepage		= ext4_invalidatepage,
+	.releasepage		= ext4_releasepage,
+	.is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext4_da_aops = {
-	.readpage	= ext4_readpage,
-	.readpages	= ext4_readpages,
-	.writepage	= ext4_da_writepage,
-	.writepages	= ext4_da_writepages,
-	.sync_page	= block_sync_page,
-	.write_begin	= ext4_da_write_begin,
-	.write_end	= ext4_da_write_end,
-	.bmap		= ext4_bmap,
-	.invalidatepage	= ext4_da_invalidatepage,
-	.releasepage	= ext4_releasepage,
-	.direct_IO	= ext4_direct_IO,
-	.migratepage	= buffer_migrate_page,
+	.readpage		= ext4_readpage,
+	.readpages		= ext4_readpages,
+	.writepage		= ext4_da_writepage,
+	.writepages		= ext4_da_writepages,
+	.sync_page		= block_sync_page,
+	.write_begin		= ext4_da_write_begin,
+	.write_end		= ext4_da_write_end,
+	.bmap			= ext4_bmap,
+	.invalidatepage		= ext4_da_invalidatepage,
+	.releasepage		= ext4_releasepage,
+	.direct_IO		= ext4_direct_IO,
+	.migratepage		= buffer_migrate_page,
+	.is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 void ext4_set_aops(struct inode *inode)
@@ -3430,6 +3577,9 @@ void ext4_truncate(struct inode *inode)
 	 * modify the block allocation tree.
 	 */
 	down_write(&ei->i_data_sem);
+
+	ext4_discard_reservation(inode);
+
 	/*
 	 * The orphan list entry will now protect us from any crash which
 	 * occurs before the truncate completes, so it is now safe to propagate
@@ -3499,8 +3649,6 @@ do_indirects:
 		;
 	}
 
-	ext4_discard_reservation(inode);
-
 	up_write(&ei->i_data_sem);
 	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
@@ -3586,6 +3734,16 @@ static int __ext4_get_inode_loc(struct inode *inode,
 	}
 	if (!buffer_uptodate(bh)) {
 		lock_buffer(bh);
+
+		/*
+		 * If the buffer has the write error flag, we have failed
+		 * to write out another inode in the same block.  In this
+		 * case, we don't have to read the block because we may
+		 * read the old inode data successfully.
+		 */
+		if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
+			set_buffer_uptodate(bh);
+
 		if (buffer_uptodate(bh)) {
 			/* someone brought it uptodate while we waited */
 			unlock_buffer(bh);
@@ -4258,57 +4416,129 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	return 0;
 }
 
+static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
+				      int chunk)
+{
+	int indirects;
+
+	/* if nrblocks are contiguous */
+	if (chunk) {
+		/*
+		 * With N contiguous data blocks, it need at most
+		 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
+		 * 2 dindirect blocks
+		 * 1 tindirect block
+		 */
+		indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
+		return indirects + 3;
+	}
+	/*
+	 * if nrblocks are not contiguous, worse case, each block touch
+	 * a indirect block, and each indirect block touch a double indirect
+	 * block, plus a triple indirect block
+	 */
+	indirects = nrblocks * 2 + 1;
+	return indirects;
+}
+
+static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+	if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+		return ext4_indirect_trans_blocks(inode, nrblocks, 0);
+	return ext4_ext_index_trans_blocks(inode, nrblocks, 0);
+}
 /*
- * How many blocks doth make a writepage()?
+ * Account for index blocks, block groups bitmaps and block group
+ * descriptor blocks if modify datablocks and index blocks
+ * worse case, the indexs blocks spread over different block groups
  *
- * With N blocks per page, it may be:
- * N data blocks
- * 2 indirect block
- * 2 dindirect
- * 1 tindirect
- * N+5 bitmap blocks (from the above)
- * N+5 group descriptor summary blocks
- * 1 inode block
- * 1 superblock.
- * 2 * EXT4_SINGLEDATA_TRANS_BLOCKS for the quote files
+ * If datablocks are discontiguous, they are possible to spread over
+ * different block groups too. If they are contiugous, with flexbg,
+ * they could still across block group boundary.
  *
- * 3 * (N + 5) + 2 + 2 * EXT4_SINGLEDATA_TRANS_BLOCKS
- *
- * With ordered or writeback data it's the same, less the N data blocks.
+ * Also account for superblock, inode, quota and xattr blocks
+ */
+int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+	int groups, gdpblocks;
+	int idxblocks;
+	int ret = 0;
+
+	/*
+	 * How many index blocks need to touch to modify nrblocks?
+	 * The "Chunk" flag indicating whether the nrblocks is
+	 * physically contiguous on disk
+	 *
+	 * For Direct IO and fallocate, they calls get_block to allocate
+	 * one single extent at a time, so they could set the "Chunk" flag
+	 */
+	idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
+
+	ret = idxblocks;
+
+	/*
+	 * Now let's see how many group bitmaps and group descriptors need
+	 * to account
+	 */
+	groups = idxblocks;
+	if (chunk)
+		groups += 1;
+	else
+		groups += nrblocks;
+
+	gdpblocks = groups;
+	if (groups > EXT4_SB(inode->i_sb)->s_groups_count)
+		groups = EXT4_SB(inode->i_sb)->s_groups_count;
+	if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
+		gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
+
+	/* bitmaps and block group descriptor blocks */
+	ret += groups + gdpblocks;
+
+	/* Blocks for super block, inode, quota and xattr blocks */
+	ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
+
+	return ret;
+}
+
+/*
+ * Calulate the total number of credits to reserve to fit
+ * the modification of a single pages into a single transaction,
+ * which may include multiple chunks of block allocations.
  *
- * If the inode's direct blocks can hold an integral number of pages then a
- * page cannot straddle two indirect blocks, and we can only touch one indirect
- * and dindirect block, and the "5" above becomes "3".
+ * This could be called via ext4_write_begin()
  *
- * This still overestimates under most circumstances.  If we were to pass the
- * start and end offsets in here as well we could do block_to_path() on each
- * block and work out the exact number of indirects which are touched.  Pah.
+ * We need to consider the worse case, when
+ * one new block per extent.
  */
-
 int ext4_writepage_trans_blocks(struct inode *inode)
 {
 	int bpp = ext4_journal_blocks_per_page(inode);
-	int indirects = (EXT4_NDIR_BLOCKS % bpp) ? 5 : 3;
 	int ret;
 
-	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-		return ext4_ext_writepage_trans_blocks(inode, bpp);
+	ret = ext4_meta_trans_blocks(inode, bpp, 0);
 
+	/* Account for data blocks for journalled mode */
 	if (ext4_should_journal_data(inode))
-		ret = 3 * (bpp + indirects) + 2;
-	else
-		ret = 2 * (bpp + indirects) + 2;
-
-#ifdef CONFIG_QUOTA
-	/* We know that structure was already allocated during DQUOT_INIT so
-	 * we will be updating only the data blocks + inodes */
-	ret += 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
-
+		ret += bpp;
 	return ret;
 }
 
 /*
+ * Calculate the journal credits for a chunk of data modification.
+ *
+ * This is called from DIO, fallocate or whoever calling
+ * ext4_get_blocks_wrap() to map/allocate a chunk of contigous disk blocks.
+ *
+ * journal buffers for data blocks are not included here, as DIO
+ * and fallocate do no need to journal data buffers.
+ */
+int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
+{
+	return ext4_meta_trans_blocks(inode, nrblocks, 1);
+}
+
+/*
  * The caller must have previously called ext4_reserve_inode_write().
  * Give this, we know that the caller already has write access to iloc->bh.
  */
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 8d141a25bbe..e0e3a5eb1dd 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -787,13 +787,16 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
 		if (bh_uptodate_or_lock(bh[i]))
 			continue;
 
+		spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
 		if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 			ext4_init_block_bitmap(sb, bh[i],
 						first_group + i, desc);
 			set_buffer_uptodate(bh[i]);
 			unlock_buffer(bh[i]);
+			spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
 			continue;
 		}
+		spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
 		get_bh(bh[i]);
 		bh[i]->b_end_io = end_buffer_read_sync;
 		submit_bh(READ, bh[i]);
@@ -2477,7 +2480,7 @@ err_freesgi:
 int ext4_mb_init(struct super_block *sb, int needs_recovery)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	unsigned i;
+	unsigned i, j;
 	unsigned offset;
 	unsigned max;
 	int ret;
@@ -2537,7 +2540,7 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 	sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
 	sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
 
-	i = sizeof(struct ext4_locality_group) * NR_CPUS;
+	i = sizeof(struct ext4_locality_group) * nr_cpu_ids;
 	sbi->s_locality_groups = kmalloc(i, GFP_KERNEL);
 	if (sbi->s_locality_groups == NULL) {
 		clear_opt(sbi->s_mount_opt, MBALLOC);
@@ -2545,11 +2548,12 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 		kfree(sbi->s_mb_maxs);
 		return -ENOMEM;
 	}
-	for (i = 0; i < NR_CPUS; i++) {
+	for (i = 0; i < nr_cpu_ids; i++) {
 		struct ext4_locality_group *lg;
 		lg = &sbi->s_locality_groups[i];
 		mutex_init(&lg->lg_mutex);
-		INIT_LIST_HEAD(&lg->lg_prealloc_list);
+		for (j = 0; j < PREALLOC_TB_SIZE; j++)
+			INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
 		spin_lock_init(&lg->lg_prealloc_lock);
 	}
 
@@ -3260,6 +3264,7 @@ static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
 				struct ext4_prealloc_space *pa)
 {
 	unsigned int len = ac->ac_o_ex.fe_len;
+
 	ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
 					&ac->ac_b_ex.fe_group,
 					&ac->ac_b_ex.fe_start);
@@ -3277,14 +3282,45 @@ static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
 }
 
 /*
+ * Return the prealloc space that have minimal distance
+ * from the goal block. @cpa is the prealloc
+ * space that is having currently known minimal distance
+ * from the goal block.
+ */
+static struct ext4_prealloc_space *
+ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
+			struct ext4_prealloc_space *pa,
+			struct ext4_prealloc_space *cpa)
+{
+	ext4_fsblk_t cur_distance, new_distance;
+
+	if (cpa == NULL) {
+		atomic_inc(&pa->pa_count);
+		return pa;
+	}
+	cur_distance = abs(goal_block - cpa->pa_pstart);
+	new_distance = abs(goal_block - pa->pa_pstart);
+
+	if (cur_distance < new_distance)
+		return cpa;
+
+	/* drop the previous reference */
+	atomic_dec(&cpa->pa_count);
+	atomic_inc(&pa->pa_count);
+	return pa;
+}
+
+/*
  * search goal blocks in preallocated space
  */
 static noinline_for_stack int
 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
 {
+	int order, i;
 	struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
 	struct ext4_locality_group *lg;
-	struct ext4_prealloc_space *pa;
+	struct ext4_prealloc_space *pa, *cpa = NULL;
+	ext4_fsblk_t goal_block;
 
 	/* only data can be preallocated */
 	if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
@@ -3322,22 +3358,38 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
 	lg = ac->ac_lg;
 	if (lg == NULL)
 		return 0;
+	order  = fls(ac->ac_o_ex.fe_len) - 1;
+	if (order > PREALLOC_TB_SIZE - 1)
+		/* The max size of hash table is PREALLOC_TB_SIZE */
+		order = PREALLOC_TB_SIZE - 1;
+
+	goal_block = ac->ac_g_ex.fe_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb) +
+		     ac->ac_g_ex.fe_start +
+		     le32_to_cpu(EXT4_SB(ac->ac_sb)->s_es->s_first_data_block);
+	/*
+	 * search for the prealloc space that is having
+	 * minimal distance from the goal block.
+	 */
+	for (i = order; i < PREALLOC_TB_SIZE; i++) {
+		rcu_read_lock();
+		list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
+					pa_inode_list) {
+			spin_lock(&pa->pa_lock);
+			if (pa->pa_deleted == 0 &&
+					pa->pa_free >= ac->ac_o_ex.fe_len) {
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(pa, &lg->lg_prealloc_list, pa_inode_list) {
-		spin_lock(&pa->pa_lock);
-		if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) {
-			atomic_inc(&pa->pa_count);
-			ext4_mb_use_group_pa(ac, pa);
+				cpa = ext4_mb_check_group_pa(goal_block,
+								pa, cpa);
+			}
 			spin_unlock(&pa->pa_lock);
-			ac->ac_criteria = 20;
-			rcu_read_unlock();
-			return 1;
 		}
-		spin_unlock(&pa->pa_lock);
+		rcu_read_unlock();
+	}
+	if (cpa) {
+		ext4_mb_use_group_pa(ac, cpa);
+		ac->ac_criteria = 20;
+		return 1;
 	}
-	rcu_read_unlock();
-
 	return 0;
 }
 
@@ -3560,6 +3612,7 @@ ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
 	pa->pa_free = pa->pa_len;
 	atomic_set(&pa->pa_count, 1);
 	spin_lock_init(&pa->pa_lock);
+	INIT_LIST_HEAD(&pa->pa_inode_list);
 	pa->pa_deleted = 0;
 	pa->pa_linear = 1;
 
@@ -3580,10 +3633,10 @@ ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
 	list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
 	ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
 
-	spin_lock(pa->pa_obj_lock);
-	list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list);
-	spin_unlock(pa->pa_obj_lock);
-
+	/*
+	 * We will later add the new pa to the right bucket
+	 * after updating the pa_free in ext4_mb_release_context
+	 */
 	return 0;
 }
 
@@ -3733,20 +3786,23 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
 
 	bitmap_bh = ext4_read_block_bitmap(sb, group);
 	if (bitmap_bh == NULL) {
-		/* error handling here */
-		ext4_mb_release_desc(&e4b);
-		BUG_ON(bitmap_bh == NULL);
+		ext4_error(sb, __func__, "Error in reading block "
+				"bitmap for %lu\n", group);
+		return 0;
 	}
 
 	err = ext4_mb_load_buddy(sb, group, &e4b);
-	BUG_ON(err != 0); /* error handling here */
+	if (err) {
+		ext4_error(sb, __func__, "Error in loading buddy "
+				"information for %lu\n", group);
+		put_bh(bitmap_bh);
+		return 0;
+	}
 
 	if (needed == 0)
 		needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
 
-	grp = ext4_get_group_info(sb, group);
 	INIT_LIST_HEAD(&list);
-
 	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
 repeat:
 	ext4_lock_group(sb, group);
@@ -3903,13 +3959,18 @@ repeat:
 		ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
 
 		err = ext4_mb_load_buddy(sb, group, &e4b);
-		BUG_ON(err != 0); /* error handling here */
+		if (err) {
+			ext4_error(sb, __func__, "Error in loading buddy "
+					"information for %lu\n", group);
+			continue;
+		}
 
 		bitmap_bh = ext4_read_block_bitmap(sb, group);
 		if (bitmap_bh == NULL) {
-			/* error handling here */
+			ext4_error(sb, __func__, "Error in reading block "
+					"bitmap for %lu\n", group);
 			ext4_mb_release_desc(&e4b);
-			BUG_ON(bitmap_bh == NULL);
+			continue;
 		}
 
 		ext4_lock_group(sb, group);
@@ -4112,22 +4173,168 @@ ext4_mb_initialize_context(struct ext4_allocation_context *ac,
 
 }
 
+static noinline_for_stack void
+ext4_mb_discard_lg_preallocations(struct super_block *sb,
+					struct ext4_locality_group *lg,
+					int order, int total_entries)
+{
+	ext4_group_t group = 0;
+	struct ext4_buddy e4b;
+	struct list_head discard_list;
+	struct ext4_prealloc_space *pa, *tmp;
+	struct ext4_allocation_context *ac;
+
+	mb_debug("discard locality group preallocation\n");
+
+	INIT_LIST_HEAD(&discard_list);
+	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
+
+	spin_lock(&lg->lg_prealloc_lock);
+	list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
+						pa_inode_list) {
+		spin_lock(&pa->pa_lock);
+		if (atomic_read(&pa->pa_count)) {
+			/*
+			 * This is the pa that we just used
+			 * for block allocation. So don't
+			 * free that
+			 */
+			spin_unlock(&pa->pa_lock);
+			continue;
+		}
+		if (pa->pa_deleted) {
+			spin_unlock(&pa->pa_lock);
+			continue;
+		}
+		/* only lg prealloc space */
+		BUG_ON(!pa->pa_linear);
+
+		/* seems this one can be freed ... */
+		pa->pa_deleted = 1;
+		spin_unlock(&pa->pa_lock);
+
+		list_del_rcu(&pa->pa_inode_list);
+		list_add(&pa->u.pa_tmp_list, &discard_list);
+
+		total_entries--;
+		if (total_entries <= 5) {
+			/*
+			 * we want to keep only 5 entries
+			 * allowing it to grow to 8. This
+			 * mak sure we don't call discard
+			 * soon for this list.
+			 */
+			break;
+		}
+	}
+	spin_unlock(&lg->lg_prealloc_lock);
+
+	list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
+
+		ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
+		if (ext4_mb_load_buddy(sb, group, &e4b)) {
+			ext4_error(sb, __func__, "Error in loading buddy "
+					"information for %lu\n", group);
+			continue;
+		}
+		ext4_lock_group(sb, group);
+		list_del(&pa->pa_group_list);
+		ext4_mb_release_group_pa(&e4b, pa, ac);
+		ext4_unlock_group(sb, group);
+
+		ext4_mb_release_desc(&e4b);
+		list_del(&pa->u.pa_tmp_list);
+		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
+	}
+	if (ac)
+		kmem_cache_free(ext4_ac_cachep, ac);
+}
+
+/*
+ * We have incremented pa_count. So it cannot be freed at this
+ * point. Also we hold lg_mutex. So no parallel allocation is
+ * possible from this lg. That means pa_free cannot be updated.
+ *
+ * A parallel ext4_mb_discard_group_preallocations is possible.
+ * which can cause the lg_prealloc_list to be updated.
+ */
+
+static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
+{
+	int order, added = 0, lg_prealloc_count = 1;
+	struct super_block *sb = ac->ac_sb;
+	struct ext4_locality_group *lg = ac->ac_lg;
+	struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
+
+	order = fls(pa->pa_free) - 1;
+	if (order > PREALLOC_TB_SIZE - 1)
+		/* The max size of hash table is PREALLOC_TB_SIZE */
+		order = PREALLOC_TB_SIZE - 1;
+	/* Add the prealloc space to lg */
+	rcu_read_lock();
+	list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
+						pa_inode_list) {
+		spin_lock(&tmp_pa->pa_lock);
+		if (tmp_pa->pa_deleted) {
+			spin_unlock(&pa->pa_lock);
+			continue;
+		}
+		if (!added && pa->pa_free < tmp_pa->pa_free) {
+			/* Add to the tail of the previous entry */
+			list_add_tail_rcu(&pa->pa_inode_list,
+						&tmp_pa->pa_inode_list);
+			added = 1;
+			/*
+			 * we want to count the total
+			 * number of entries in the list
+			 */
+		}
+		spin_unlock(&tmp_pa->pa_lock);
+		lg_prealloc_count++;
+	}
+	if (!added)
+		list_add_tail_rcu(&pa->pa_inode_list,
+					&lg->lg_prealloc_list[order]);
+	rcu_read_unlock();
+
+	/* Now trim the list to be not more than 8 elements */
+	if (lg_prealloc_count > 8) {
+		ext4_mb_discard_lg_preallocations(sb, lg,
+						order, lg_prealloc_count);
+		return;
+	}
+	return ;
+}
+
 /*
  * release all resource we used in allocation
  */
 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
 {
-	if (ac->ac_pa) {
-		if (ac->ac_pa->pa_linear) {
+	struct ext4_prealloc_space *pa = ac->ac_pa;
+	if (pa) {
+		if (pa->pa_linear) {
 			/* see comment in ext4_mb_use_group_pa() */
-			spin_lock(&ac->ac_pa->pa_lock);
-			ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len;
-			ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len;
-			ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len;
-			ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len;
-			spin_unlock(&ac->ac_pa->pa_lock);
+			spin_lock(&pa->pa_lock);
+			pa->pa_pstart += ac->ac_b_ex.fe_len;
+			pa->pa_lstart += ac->ac_b_ex.fe_len;
+			pa->pa_free -= ac->ac_b_ex.fe_len;
+			pa->pa_len -= ac->ac_b_ex.fe_len;
+			spin_unlock(&pa->pa_lock);
+			/*
+			 * We want to add the pa to the right bucket.
+			 * Remove it from the list and while adding
+			 * make sure the list to which we are adding
+			 * doesn't grow big.
+			 */
+			if (likely(pa->pa_free)) {
+				spin_lock(pa->pa_obj_lock);
+				list_del_rcu(&pa->pa_inode_list);
+				spin_unlock(pa->pa_obj_lock);
+				ext4_mb_add_n_trim(ac);
+			}
 		}
-		ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa);
+		ext4_mb_put_pa(ac, ac->ac_sb, pa);
 	}
 	if (ac->ac_bitmap_page)
 		page_cache_release(ac->ac_bitmap_page);
@@ -4420,11 +4627,15 @@ do_more:
 		count -= overflow;
 	}
 	bitmap_bh = ext4_read_block_bitmap(sb, block_group);
-	if (!bitmap_bh)
+	if (!bitmap_bh) {
+		err = -EIO;
 		goto error_return;
+	}
 	gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
-	if (!gdp)
+	if (!gdp) {
+		err = -EIO;
 		goto error_return;
+	}
 
 	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
 	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index bfe6add46bc..c7c9906c2a7 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -164,11 +164,17 @@ struct ext4_free_extent {
  * Locality group:
  *   we try to group all related changes together
  *   so that writeback can flush/allocate them together as well
+ *   Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC
+ *   (512). We store prealloc space into the hash based on the pa_free blocks
+ *   order value.ie, fls(pa_free)-1;
  */
+#define PREALLOC_TB_SIZE 10
 struct ext4_locality_group {
 	/* for allocator */
-	struct mutex		lg_mutex;	/* to serialize allocates */
-	struct list_head	lg_prealloc_list;/* list of preallocations */
+	/* to serialize allocates */
+	struct mutex		lg_mutex;
+	/* list of preallocations */
+	struct list_head	lg_prealloc_list[PREALLOC_TB_SIZE];
 	spinlock_t		lg_prealloc_lock;
 };
 
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index b9e077ba07e..46fc0b5b12b 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -53,7 +53,8 @@ static int finish_range(handle_t *handle, struct inode *inode,
 	 * credit. But below we try to not accumalate too much
 	 * of them by restarting the journal.
 	 */
-	needed = ext4_ext_calc_credits_for_insert(inode, path);
+	needed = ext4_ext_calc_credits_for_single_extent(inode,
+		    lb->last_block - lb->first_block + 1, path);
 
 	/*
 	 * Make sure the credit we accumalated is not really high
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index f000fbe2cd9..b3d35604ea1 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -73,7 +73,7 @@ static int verify_group_input(struct super_block *sb,
 			     "Inode bitmap not in group (block %llu)",
 			     (unsigned long long)input->inode_bitmap);
 	else if (outside(input->inode_table, start, end) ||
-	         outside(itend - 1, start, end))
+		 outside(itend - 1, start, end))
 		ext4_warning(sb, __func__,
 			     "Inode table not in group (blocks %llu-%llu)",
 			     (unsigned long long)input->inode_table, itend - 1);
@@ -104,7 +104,7 @@ static int verify_group_input(struct super_block *sb,
 			     (unsigned long long)input->inode_bitmap,
 			     start, metaend - 1);
 	else if (inside(input->inode_table, start, metaend) ||
-	         inside(itend - 1, start, metaend))
+		 inside(itend - 1, start, metaend))
 		ext4_warning(sb, __func__,
 			     "Inode table (%llu-%llu) overlaps"
 			     "GDT table (%llu-%llu)",
@@ -158,9 +158,9 @@ static int extend_or_restart_transaction(handle_t *handle, int thresh,
 	if (err) {
 		if ((err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
 			return err;
-	        if ((err = ext4_journal_get_write_access(handle, bh)))
+		if ((err = ext4_journal_get_write_access(handle, bh)))
 			return err;
-        }
+	}
 
 	return 0;
 }
@@ -416,11 +416,11 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
 		       "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
 		       gdb_num);
 
-	/*
-	 * If we are not using the primary superblock/GDT copy don't resize,
-	 * because the user tools have no way of handling this.  Probably a
-	 * bad time to do it anyways.
-	 */
+        /*
+         * If we are not using the primary superblock/GDT copy don't resize,
+         * because the user tools have no way of handling this.  Probably a
+         * bad time to do it anyways.
+         */
 	if (EXT4_SB(sb)->s_sbh->b_blocknr !=
 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
 		ext4_warning(sb, __func__,
@@ -507,14 +507,14 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
 	return 0;
 
 exit_inode:
-	//ext4_journal_release_buffer(handle, iloc.bh);
+	/* ext4_journal_release_buffer(handle, iloc.bh); */
 	brelse(iloc.bh);
 exit_dindj:
-	//ext4_journal_release_buffer(handle, dind);
+	/* ext4_journal_release_buffer(handle, dind); */
 exit_primary:
-	//ext4_journal_release_buffer(handle, *primary);
+	/* ext4_journal_release_buffer(handle, *primary); */
 exit_sbh:
-	//ext4_journal_release_buffer(handle, *primary);
+	/* ext4_journal_release_buffer(handle, *primary); */
 exit_dind:
 	brelse(dind);
 exit_bh:
@@ -773,7 +773,8 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 
 	if (reserved_gdb || gdb_off == 0) {
 		if (!EXT4_HAS_COMPAT_FEATURE(sb,
-					     EXT4_FEATURE_COMPAT_RESIZE_INODE)){
+					     EXT4_FEATURE_COMPAT_RESIZE_INODE)
+		    || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
 			ext4_warning(sb, __func__,
 				     "No reserved GDT blocks, can't resize");
 			return -EPERM;
@@ -818,12 +819,12 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 	if ((err = ext4_journal_get_write_access(handle, sbi->s_sbh)))
 		goto exit_journal;
 
-	/*
-	 * We will only either add reserved group blocks to a backup group
-	 * or remove reserved blocks for the first group in a new group block.
-	 * Doing both would be mean more complex code, and sane people don't
-	 * use non-sparse filesystems anymore.  This is already checked above.
-	 */
+        /*
+         * We will only either add reserved group blocks to a backup group
+         * or remove reserved blocks for the first group in a new group block.
+         * Doing both would be mean more complex code, and sane people don't
+         * use non-sparse filesystems anymore.  This is already checked above.
+         */
 	if (gdb_off) {
 		primary = sbi->s_group_desc[gdb_num];
 		if ((err = ext4_journal_get_write_access(handle, primary)))
@@ -835,24 +836,24 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 	} else if ((err = add_new_gdb(handle, inode, input, &primary)))
 		goto exit_journal;
 
-	/*
-	 * OK, now we've set up the new group.  Time to make it active.
-	 *
-	 * Current kernels don't lock all allocations via lock_super(),
-	 * so we have to be safe wrt. concurrent accesses the group
-	 * data.  So we need to be careful to set all of the relevant
-	 * group descriptor data etc. *before* we enable the group.
-	 *
-	 * The key field here is sbi->s_groups_count: as long as
-	 * that retains its old value, nobody is going to access the new
-	 * group.
-	 *
-	 * So first we update all the descriptor metadata for the new
-	 * group; then we update the total disk blocks count; then we
-	 * update the groups count to enable the group; then finally we
-	 * update the free space counts so that the system can start
-	 * using the new disk blocks.
-	 */
+        /*
+         * OK, now we've set up the new group.  Time to make it active.
+         *
+         * Current kernels don't lock all allocations via lock_super(),
+         * so we have to be safe wrt. concurrent accesses the group
+         * data.  So we need to be careful to set all of the relevant
+         * group descriptor data etc. *before* we enable the group.
+         *
+         * The key field here is sbi->s_groups_count: as long as
+         * that retains its old value, nobody is going to access the new
+         * group.
+         *
+         * So first we update all the descriptor metadata for the new
+         * group; then we update the total disk blocks count; then we
+         * update the groups count to enable the group; then finally we
+         * update the free space counts so that the system can start
+         * using the new disk blocks.
+         */
 
 	/* Update group descriptor block for new group */
 	gdp = (struct ext4_group_desc *)((char *)primary->b_data +
@@ -946,7 +947,8 @@ exit_put:
 	return err;
 } /* ext4_group_add */
 
-/* Extend the filesystem to the new number of blocks specified.  This entry
+/*
+ * Extend the filesystem to the new number of blocks specified.  This entry
  * point is only used to extend the current filesystem to the end of the last
  * existing group.  It can be accessed via ioctl, or by "remount,resize=<size>"
  * for emergencies (because it has no dependencies on reserved blocks).
@@ -1024,7 +1026,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
 			     o_blocks_count + add, add);
 
 	/* See if the device is actually as big as what was requested */
-	bh = sb_bread(sb, o_blocks_count + add -1);
+	bh = sb_bread(sb, o_blocks_count + add - 1);
 	if (!bh) {
 		ext4_warning(sb, __func__,
 			     "can't read last block, resize aborted");
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1cb371dcd60..566344b926b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -49,20 +49,19 @@ static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
 			     unsigned long journal_devnum);
 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
 			       unsigned int);
-static void ext4_commit_super (struct super_block * sb,
-			       struct ext4_super_block * es,
-			       int sync);
-static void ext4_mark_recovery_complete(struct super_block * sb,
-					struct ext4_super_block * es);
-static void ext4_clear_journal_err(struct super_block * sb,
-				   struct ext4_super_block * es);
+static void ext4_commit_super(struct super_block *sb,
+			      struct ext4_super_block *es, int sync);
+static void ext4_mark_recovery_complete(struct super_block *sb,
+					struct ext4_super_block *es);
+static void ext4_clear_journal_err(struct super_block *sb,
+				   struct ext4_super_block *es);
 static int ext4_sync_fs(struct super_block *sb, int wait);
-static const char *ext4_decode_error(struct super_block * sb, int errno,
+static const char *ext4_decode_error(struct super_block *sb, int errno,
 				     char nbuf[16]);
-static int ext4_remount (struct super_block * sb, int * flags, char * data);
-static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
+static int ext4_remount(struct super_block *sb, int *flags, char *data);
+static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
 static void ext4_unlockfs(struct super_block *sb);
-static void ext4_write_super (struct super_block * sb);
+static void ext4_write_super(struct super_block *sb);
 static void ext4_write_super_lockfs(struct super_block *sb);
 
 
@@ -211,15 +210,15 @@ static void ext4_handle_error(struct super_block *sb)
 	if (sb->s_flags & MS_RDONLY)
 		return;
 
-	if (!test_opt (sb, ERRORS_CONT)) {
+	if (!test_opt(sb, ERRORS_CONT)) {
 		journal_t *journal = EXT4_SB(sb)->s_journal;
 
 		EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 		if (journal)
 			jbd2_journal_abort(journal, -EIO);
 	}
-	if (test_opt (sb, ERRORS_RO)) {
-		printk (KERN_CRIT "Remounting filesystem read-only\n");
+	if (test_opt(sb, ERRORS_RO)) {
+		printk(KERN_CRIT "Remounting filesystem read-only\n");
 		sb->s_flags |= MS_RDONLY;
 	}
 	ext4_commit_super(sb, es, 1);
@@ -228,13 +227,13 @@ static void ext4_handle_error(struct super_block *sb)
 			sb->s_id);
 }
 
-void ext4_error (struct super_block * sb, const char * function,
-		 const char * fmt, ...)
+void ext4_error(struct super_block *sb, const char *function,
+		const char *fmt, ...)
 {
 	va_list args;
 
 	va_start(args, fmt);
-	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
+	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 	vprintk(fmt, args);
 	printk("\n");
 	va_end(args);
@@ -242,7 +241,7 @@ void ext4_error (struct super_block * sb, const char * function,
 	ext4_handle_error(sb);
 }
 
-static const char *ext4_decode_error(struct super_block * sb, int errno,
+static const char *ext4_decode_error(struct super_block *sb, int errno,
 				     char nbuf[16])
 {
 	char *errstr = NULL;
@@ -278,8 +277,7 @@ static const char *ext4_decode_error(struct super_block * sb, int errno,
 /* __ext4_std_error decodes expected errors from journaling functions
  * automatically and invokes the appropriate error response.  */
 
-void __ext4_std_error (struct super_block * sb, const char * function,
-		       int errno)
+void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 {
 	char nbuf[16];
 	const char *errstr;
@@ -292,8 +290,8 @@ void __ext4_std_error (struct super_block * sb, const char * function,
 		return;
 
 	errstr = ext4_decode_error(sb, errno, nbuf);
-	printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
-		sb->s_id, function, errstr);
+	printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
+	       sb->s_id, function, errstr);
 
 	ext4_handle_error(sb);
 }
@@ -308,15 +306,15 @@ void __ext4_std_error (struct super_block * sb, const char * function,
  * case we take the easy way out and panic immediately.
  */
 
-void ext4_abort (struct super_block * sb, const char * function,
-		 const char * fmt, ...)
+void ext4_abort(struct super_block *sb, const char *function,
+		const char *fmt, ...)
 {
 	va_list args;
 
-	printk (KERN_CRIT "ext4_abort called.\n");
+	printk(KERN_CRIT "ext4_abort called.\n");
 
 	va_start(args, fmt);
-	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
+	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 	vprintk(fmt, args);
 	printk("\n");
 	va_end(args);
@@ -334,8 +332,8 @@ void ext4_abort (struct super_block * sb, const char * function,
 	jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 }
 
-void ext4_warning (struct super_block * sb, const char * function,
-		   const char * fmt, ...)
+void ext4_warning(struct super_block *sb, const char *function,
+		  const char *fmt, ...)
 {
 	va_list args;
 
@@ -496,7 +494,7 @@ static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 	}
 }
 
-static void ext4_put_super (struct super_block * sb)
+static void ext4_put_super(struct super_block *sb)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_super_block *es = sbi->s_es;
@@ -570,6 +568,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 #endif
 	ei->i_block_alloc_info = NULL;
 	ei->vfs_inode.i_version = 1;
+	ei->vfs_inode.i_data.writeback_index = 0;
 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 	INIT_LIST_HEAD(&ei->i_prealloc_list);
 	spin_lock_init(&ei->i_prealloc_lock);
@@ -595,7 +594,7 @@ static void ext4_destroy_inode(struct inode *inode)
 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 }
 
-static void init_once(struct kmem_cache *cachep, void *foo)
+static void init_once(void *foo)
 {
 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 
@@ -647,7 +646,8 @@ static void ext4_clear_inode(struct inode *inode)
 				       &EXT4_I(inode)->jinode);
 }
 
-static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
+static inline void ext4_show_quota_options(struct seq_file *seq,
+					   struct super_block *sb)
 {
 #if defined(CONFIG_QUOTA)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -822,8 +822,8 @@ static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 }
 
 #ifdef CONFIG_QUOTA
-#define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
-#define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
+#define QTYPE2NAME(t) ((t) == USRQUOTA?"user":"group")
+#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 
 static int ext4_dquot_initialize(struct inode *inode, int type);
 static int ext4_dquot_drop(struct inode *inode);
@@ -991,12 +991,12 @@ static ext4_fsblk_t get_sb_block(void **data)
 	return sb_block;
 }
 
-static int parse_options (char *options, struct super_block *sb,
-			  unsigned int *inum, unsigned long *journal_devnum,
-			  ext4_fsblk_t *n_blocks_count, int is_remount)
+static int parse_options(char *options, struct super_block *sb,
+			 unsigned int *inum, unsigned long *journal_devnum,
+			 ext4_fsblk_t *n_blocks_count, int is_remount)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	char * p;
+	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int data_opt = 0;
 	int option;
@@ -1009,7 +1009,7 @@ static int parse_options (char *options, struct super_block *sb,
 	if (!options)
 		return 1;
 
-	while ((p = strsep (&options, ",")) != NULL) {
+	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
 		if (!*p)
 			continue;
@@ -1017,16 +1017,16 @@ static int parse_options (char *options, struct super_block *sb,
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_bsd_df:
-			clear_opt (sbi->s_mount_opt, MINIX_DF);
+			clear_opt(sbi->s_mount_opt, MINIX_DF);
 			break;
 		case Opt_minix_df:
-			set_opt (sbi->s_mount_opt, MINIX_DF);
+			set_opt(sbi->s_mount_opt, MINIX_DF);
 			break;
 		case Opt_grpid:
-			set_opt (sbi->s_mount_opt, GRPID);
+			set_opt(sbi->s_mount_opt, GRPID);
 			break;
 		case Opt_nogrpid:
-			clear_opt (sbi->s_mount_opt, GRPID);
+			clear_opt(sbi->s_mount_opt, GRPID);
 			break;
 		case Opt_resuid:
 			if (match_int(&args[0], &option))
@@ -1043,41 +1043,41 @@ static int parse_options (char *options, struct super_block *sb,
 			/* *sb_block = match_int(&args[0]); */
 			break;
 		case Opt_err_panic:
-			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
-			clear_opt (sbi->s_mount_opt, ERRORS_RO);
-			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
+			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
+			clear_opt(sbi->s_mount_opt, ERRORS_RO);
+			set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 			break;
 		case Opt_err_ro:
-			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
-			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
-			set_opt (sbi->s_mount_opt, ERRORS_RO);
+			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
+			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
+			set_opt(sbi->s_mount_opt, ERRORS_RO);
 			break;
 		case Opt_err_cont:
-			clear_opt (sbi->s_mount_opt, ERRORS_RO);
-			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
-			set_opt (sbi->s_mount_opt, ERRORS_CONT);
+			clear_opt(sbi->s_mount_opt, ERRORS_RO);
+			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
+			set_opt(sbi->s_mount_opt, ERRORS_CONT);
 			break;
 		case Opt_nouid32:
-			set_opt (sbi->s_mount_opt, NO_UID32);
+			set_opt(sbi->s_mount_opt, NO_UID32);
 			break;
 		case Opt_nocheck:
-			clear_opt (sbi->s_mount_opt, CHECK);
+			clear_opt(sbi->s_mount_opt, CHECK);
 			break;
 		case Opt_debug:
-			set_opt (sbi->s_mount_opt, DEBUG);
+			set_opt(sbi->s_mount_opt, DEBUG);
 			break;
 		case Opt_oldalloc:
-			set_opt (sbi->s_mount_opt, OLDALLOC);
+			set_opt(sbi->s_mount_opt, OLDALLOC);
 			break;
 		case Opt_orlov:
-			clear_opt (sbi->s_mount_opt, OLDALLOC);
+			clear_opt(sbi->s_mount_opt, OLDALLOC);
 			break;
 #ifdef CONFIG_EXT4DEV_FS_XATTR
 		case Opt_user_xattr:
-			set_opt (sbi->s_mount_opt, XATTR_USER);
+			set_opt(sbi->s_mount_opt, XATTR_USER);
 			break;
 		case Opt_nouser_xattr:
-			clear_opt (sbi->s_mount_opt, XATTR_USER);
+			clear_opt(sbi->s_mount_opt, XATTR_USER);
 			break;
 #else
 		case Opt_user_xattr:
@@ -1115,7 +1115,7 @@ static int parse_options (char *options, struct super_block *sb,
 				       "journal on remount\n");
 				return 0;
 			}
-			set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
+			set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
 			break;
 		case Opt_journal_inum:
 			if (is_remount) {
@@ -1145,7 +1145,7 @@ static int parse_options (char *options, struct super_block *sb,
 			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
 			break;
 		case Opt_noload:
-			set_opt (sbi->s_mount_opt, NOLOAD);
+			set_opt(sbi->s_mount_opt, NOLOAD);
 			break;
 		case Opt_commit:
 			if (match_int(&args[0], &option))
@@ -1331,7 +1331,7 @@ set_qf_format:
 					"on this filesystem, use tune2fs\n");
 				return 0;
 			}
-			set_opt (sbi->s_mount_opt, EXTENTS);
+			set_opt(sbi->s_mount_opt, EXTENTS);
 			break;
 		case Opt_noextents:
 			/*
@@ -1348,7 +1348,7 @@ set_qf_format:
 						"-o noextents options\n");
 				return 0;
 			}
-			clear_opt (sbi->s_mount_opt, EXTENTS);
+			clear_opt(sbi->s_mount_opt, EXTENTS);
 			break;
 		case Opt_i_version:
 			set_opt(sbi->s_mount_opt, I_VERSION);
@@ -1374,9 +1374,9 @@ set_qf_format:
 			set_opt(sbi->s_mount_opt, DELALLOC);
 			break;
 		default:
-			printk (KERN_ERR
-				"EXT4-fs: Unrecognized mount option \"%s\" "
-				"or missing value\n", p);
+			printk(KERN_ERR
+			       "EXT4-fs: Unrecognized mount option \"%s\" "
+			       "or missing value\n", p);
 			return 0;
 		}
 	}
@@ -1423,31 +1423,31 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 	int res = 0;
 
 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
-		printk (KERN_ERR "EXT4-fs warning: revision level too high, "
-			"forcing read-only mode\n");
+		printk(KERN_ERR "EXT4-fs warning: revision level too high, "
+		       "forcing read-only mode\n");
 		res = MS_RDONLY;
 	}
 	if (read_only)
 		return res;
 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
-		printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
+		       "running e2fsck is recommended\n");
 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
-		printk (KERN_WARNING
-			"EXT4-fs warning: mounting fs with errors, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING
+		       "EXT4-fs warning: mounting fs with errors, "
+		       "running e2fsck is recommended\n");
 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 		 le16_to_cpu(es->s_mnt_count) >=
 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
-		printk (KERN_WARNING
-			"EXT4-fs warning: maximal mount count reached, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING
+		       "EXT4-fs warning: maximal mount count reached, "
+		       "running e2fsck is recommended\n");
 	else if (le32_to_cpu(es->s_checkinterval) &&
 		(le32_to_cpu(es->s_lastcheck) +
 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
-		printk (KERN_WARNING
-			"EXT4-fs warning: checktime reached, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING
+		       "EXT4-fs warning: checktime reached, "
+		       "running e2fsck is recommended\n");
 #if 0
 		/* @@@ We _will_ want to clear the valid bit if we find
 		 * inconsistencies, to force a fsck at reboot.  But for
@@ -1506,14 +1506,13 @@ static int ext4_fill_flex_info(struct super_block *sb)
 
 	flex_group_count = (sbi->s_groups_count + groups_per_flex - 1) /
 		groups_per_flex;
-	sbi->s_flex_groups = kmalloc(flex_group_count *
+	sbi->s_flex_groups = kzalloc(flex_group_count *
 				     sizeof(struct flex_groups), GFP_KERNEL);
 	if (sbi->s_flex_groups == NULL) {
-		printk(KERN_ERR "EXT4-fs: not enough memory\n");
+		printk(KERN_ERR "EXT4-fs: not enough memory for "
+				"%lu flex groups\n", flex_group_count);
 		goto failed;
 	}
-	memset(sbi->s_flex_groups, 0, flex_group_count *
-	       sizeof(struct flex_groups));
 
 	gdp = ext4_get_group_desc(sb, 1, &bh);
 	block_bitmap = ext4_block_bitmap(sb, gdp) - 1;
@@ -1597,16 +1596,14 @@ static int ext4_check_descriptors(struct super_block *sb)
 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
 
 		block_bitmap = ext4_block_bitmap(sb, gdp);
-		if (block_bitmap < first_block || block_bitmap > last_block)
-		{
+		if (block_bitmap < first_block || block_bitmap > last_block) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Block bitmap for group %lu not in group "
 			       "(block %llu)!", i, block_bitmap);
 			return 0;
 		}
 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
-		if (inode_bitmap < first_block || inode_bitmap > last_block)
-		{
+		if (inode_bitmap < first_block || inode_bitmap > last_block) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Inode bitmap for group %lu not in group "
 			       "(block %llu)!", i, inode_bitmap);
@@ -1614,26 +1611,28 @@ static int ext4_check_descriptors(struct super_block *sb)
 		}
 		inode_table = ext4_inode_table(sb, gdp);
 		if (inode_table < first_block ||
-		    inode_table + sbi->s_itb_per_group - 1 > last_block)
-		{
+		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Inode table for group %lu not in group "
 			       "(block %llu)!", i, inode_table);
 			return 0;
 		}
+		spin_lock(sb_bgl_lock(sbi, i));
 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Checksum for group %lu failed (%u!=%u)\n",
 			       i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
 			       gdp)), le16_to_cpu(gdp->bg_checksum));
-			return 0;
+			if (!(sb->s_flags & MS_RDONLY))
+				return 0;
 		}
+		spin_unlock(sb_bgl_lock(sbi, i));
 		if (!flexbg_flag)
 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
 	}
 
 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
-	sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
+	sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
 	return 1;
 }
 
@@ -1654,8 +1653,8 @@ static int ext4_check_descriptors(struct super_block *sb)
  * e2fsck was run on this filesystem, and it must have already done the orphan
  * inode cleanup for us, so we can safely abort without any further action.
  */
-static void ext4_orphan_cleanup (struct super_block * sb,
-				 struct ext4_super_block * es)
+static void ext4_orphan_cleanup(struct super_block *sb,
+				struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
 	int nr_orphans = 0, nr_truncates = 0;
@@ -1732,7 +1731,7 @@ static void ext4_orphan_cleanup (struct super_block * sb,
 		iput(inode);  /* The delete magic happens here! */
 	}
 
-#define PLURAL(x) (x), ((x)==1) ? "" : "s"
+#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
 
 	if (nr_orphans)
 		printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
@@ -1899,12 +1898,12 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
 	return 0;
 }
 
-static int ext4_fill_super (struct super_block *sb, void *data, int silent)
+static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 				__releases(kernel_lock)
 				__acquires(kernel_lock)
 
 {
-	struct buffer_head * bh;
+	struct buffer_head *bh;
 	struct ext4_super_block *es = NULL;
 	struct ext4_sb_info *sbi;
 	ext4_fsblk_t block;
@@ -1953,7 +1952,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	}
 
 	if (!(bh = sb_bread(sb, logical_sb_block))) {
-		printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
+		printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
 		goto out_fail;
 	}
 	/*
@@ -2026,8 +2025,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	set_opt(sbi->s_mount_opt, DELALLOC);
 
 
-	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
-			    NULL, 0))
+	if (!parse_options((char *) data, sb, &journal_inum, &journal_devnum,
+			   NULL, 0))
 		goto failed_mount;
 
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
@@ -2102,7 +2101,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 			goto failed_mount;
 		}
 
-		brelse (bh);
+		brelse(bh);
 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
 		offset = do_div(logical_sb_block, blocksize);
 		bh = sb_bread(sb, logical_sb_block);
@@ -2114,8 +2113,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
 		sbi->s_es = es;
 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
-			printk (KERN_ERR
-				"EXT4-fs: Magic mismatch, very weird !\n");
+			printk(KERN_ERR
+			       "EXT4-fs: Magic mismatch, very weird !\n");
 			goto failed_mount;
 		}
 	}
@@ -2132,9 +2131,9 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
 		    (!is_power_of_2(sbi->s_inode_size)) ||
 		    (sbi->s_inode_size > blocksize)) {
-			printk (KERN_ERR
-				"EXT4-fs: unsupported inode size: %d\n",
-				sbi->s_inode_size);
+			printk(KERN_ERR
+			       "EXT4-fs: unsupported inode size: %d\n",
+			       sbi->s_inode_size);
 			goto failed_mount;
 		}
 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
@@ -2166,20 +2165,20 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	sbi->s_mount_state = le16_to_cpu(es->s_state);
 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
-	for (i=0; i < 4; i++)
+	for (i = 0; i < 4; i++)
 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
 	sbi->s_def_hash_version = es->s_def_hash_version;
 
 	if (sbi->s_blocks_per_group > blocksize * 8) {
-		printk (KERN_ERR
-			"EXT4-fs: #blocks per group too big: %lu\n",
-			sbi->s_blocks_per_group);
+		printk(KERN_ERR
+		       "EXT4-fs: #blocks per group too big: %lu\n",
+		       sbi->s_blocks_per_group);
 		goto failed_mount;
 	}
 	if (sbi->s_inodes_per_group > blocksize * 8) {
-		printk (KERN_ERR
-			"EXT4-fs: #inodes per group too big: %lu\n",
-			sbi->s_inodes_per_group);
+		printk(KERN_ERR
+		       "EXT4-fs: #inodes per group too big: %lu\n",
+		       sbi->s_inodes_per_group);
 		goto failed_mount;
 	}
 
@@ -2213,10 +2212,10 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	sbi->s_groups_count = blocks_count;
 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
 		   EXT4_DESC_PER_BLOCK(sb);
-	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
+	sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
 				    GFP_KERNEL);
 	if (sbi->s_group_desc == NULL) {
-		printk (KERN_ERR "EXT4-fs: not enough memory\n");
+		printk(KERN_ERR "EXT4-fs: not enough memory\n");
 		goto failed_mount;
 	}
 
@@ -2226,13 +2225,13 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		block = descriptor_loc(sb, logical_sb_block, i);
 		sbi->s_group_desc[i] = sb_bread(sb, block);
 		if (!sbi->s_group_desc[i]) {
-			printk (KERN_ERR "EXT4-fs: "
-				"can't read group descriptor %d\n", i);
+			printk(KERN_ERR "EXT4-fs: "
+			       "can't read group descriptor %d\n", i);
 			db_count = i;
 			goto failed_mount2;
 		}
 	}
-	if (!ext4_check_descriptors (sb)) {
+	if (!ext4_check_descriptors(sb)) {
 		printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
 		goto failed_mount2;
 	}
@@ -2308,11 +2307,11 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		    EXT4_SB(sb)->s_journal->j_failed_commit) {
 			printk(KERN_CRIT "EXT4-fs error (device %s): "
 			       "ext4_fill_super: Journal transaction "
-			       "%u is corrupt\n", sb->s_id, 
+			       "%u is corrupt\n", sb->s_id,
 			       EXT4_SB(sb)->s_journal->j_failed_commit);
-			if (test_opt (sb, ERRORS_RO)) {
-				printk (KERN_CRIT
-					"Mounting filesystem read-only\n");
+			if (test_opt(sb, ERRORS_RO)) {
+				printk(KERN_CRIT
+				       "Mounting filesystem read-only\n");
 				sb->s_flags |= MS_RDONLY;
 				EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 				es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
@@ -2332,9 +2331,9 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 			goto failed_mount3;
 	} else {
 		if (!silent)
-			printk (KERN_ERR
-				"ext4: No journal on filesystem on %s\n",
-				sb->s_id);
+			printk(KERN_ERR
+			       "ext4: No journal on filesystem on %s\n",
+			       sb->s_id);
 		goto failed_mount3;
 	}
 
@@ -2418,7 +2417,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto failed_mount4;
 	}
 
-	ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
+	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
 
 	/* determine the minimum size of new large inodes, if present */
 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
@@ -2457,12 +2456,12 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	ext4_orphan_cleanup(sb, es);
 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
 	if (needs_recovery)
-		printk (KERN_INFO "EXT4-fs: recovery complete.\n");
+		printk(KERN_INFO "EXT4-fs: recovery complete.\n");
 	ext4_mark_recovery_complete(sb, es);
-	printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
-		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
-		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
-		"writeback");
+	printk(KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
+	       test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
+	       test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
+	       "writeback");
 
 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
 		printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
@@ -2575,14 +2574,14 @@ static journal_t *ext4_get_journal(struct super_block *sb,
 static journal_t *ext4_get_dev_journal(struct super_block *sb,
 				       dev_t j_dev)
 {
-	struct buffer_head * bh;
+	struct buffer_head *bh;
 	journal_t *journal;
 	ext4_fsblk_t start;
 	ext4_fsblk_t len;
 	int hblock, blocksize;
 	ext4_fsblk_t sb_block;
 	unsigned long offset;
-	struct ext4_super_block * es;
+	struct ext4_super_block *es;
 	struct block_device *bdev;
 
 	bdev = ext4_blkdev_get(j_dev);
@@ -2697,8 +2696,8 @@ static int ext4_load_journal(struct super_block *sb,
 					"unavailable, cannot proceed.\n");
 				return -EROFS;
 			}
-			printk (KERN_INFO "EXT4-fs: write access will "
-					"be enabled during recovery.\n");
+			printk(KERN_INFO "EXT4-fs: write access will "
+			       "be enabled during recovery.\n");
 		}
 	}
 
@@ -2751,8 +2750,8 @@ static int ext4_load_journal(struct super_block *sb,
 	return 0;
 }
 
-static int ext4_create_journal(struct super_block * sb,
-			       struct ext4_super_block * es,
+static int ext4_create_journal(struct super_block *sb,
+			       struct ext4_super_block *es,
 			       unsigned int journal_inum)
 {
 	journal_t *journal;
@@ -2793,9 +2792,8 @@ static int ext4_create_journal(struct super_block * sb,
 	return 0;
 }
 
-static void ext4_commit_super (struct super_block * sb,
-			       struct ext4_super_block * es,
-			       int sync)
+static void ext4_commit_super(struct super_block *sb,
+			      struct ext4_super_block *es, int sync)
 {
 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
 
@@ -2816,8 +2814,8 @@ static void ext4_commit_super (struct super_block * sb,
  * remounting) the filesystem readonly, then we will end up with a
  * consistent fs on disk.  Record that fact.
  */
-static void ext4_mark_recovery_complete(struct super_block * sb,
-					struct ext4_super_block * es)
+static void ext4_mark_recovery_complete(struct super_block *sb,
+					struct ext4_super_block *es)
 {
 	journal_t *journal = EXT4_SB(sb)->s_journal;
 
@@ -2839,8 +2837,8 @@ static void ext4_mark_recovery_complete(struct super_block * sb,
  * has recorded an error from a previous lifetime, move that error to the
  * main filesystem now.
  */
-static void ext4_clear_journal_err(struct super_block * sb,
-				   struct ext4_super_block * es)
+static void ext4_clear_journal_err(struct super_block *sb,
+				   struct ext4_super_block *es)
 {
 	journal_t *journal;
 	int j_errno;
@@ -2865,7 +2863,7 @@ static void ext4_clear_journal_err(struct super_block * sb,
 
 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
-		ext4_commit_super (sb, es, 1);
+		ext4_commit_super(sb, es, 1);
 
 		jbd2_journal_clear_err(journal);
 	}
@@ -2898,7 +2896,7 @@ int ext4_force_commit(struct super_block *sb)
  * This implicitly triggers the writebehind on sync().
  */
 
-static void ext4_write_super (struct super_block * sb)
+static void ext4_write_super(struct super_block *sb)
 {
 	if (mutex_trylock(&sb->s_lock) != 0)
 		BUG();
@@ -2954,13 +2952,14 @@ static void ext4_unlockfs(struct super_block *sb)
 	}
 }
 
-static int ext4_remount (struct super_block * sb, int * flags, char * data)
+static int ext4_remount(struct super_block *sb, int *flags, char *data)
 {
-	struct ext4_super_block * es;
+	struct ext4_super_block *es;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	ext4_fsblk_t n_blocks_count = 0;
 	unsigned long old_sb_flags;
 	struct ext4_mount_options old_opts;
+	ext4_group_t g;
 	int err;
 #ifdef CONFIG_QUOTA
 	int i;
@@ -3039,6 +3038,26 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data)
 			}
 
 			/*
+			 * Make sure the group descriptor checksums
+			 * are sane.  If they aren't, refuse to
+			 * remount r/w.
+			 */
+			for (g = 0; g < sbi->s_groups_count; g++) {
+				struct ext4_group_desc *gdp =
+					ext4_get_group_desc(sb, g, NULL);
+
+				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
+					printk(KERN_ERR
+	       "EXT4-fs: ext4_remount: "
+		"Checksum for group %lu failed (%u!=%u)\n",
+		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
+					       le16_to_cpu(gdp->bg_checksum));
+					err = -EINVAL;
+					goto restore_opts;
+				}
+			}
+
+			/*
 			 * If we have an unprocessed orphan list hanging
 			 * around from a previously readonly bdev mount,
 			 * require a full umount/remount for now.
@@ -3063,7 +3082,7 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data)
 			sbi->s_mount_state = le16_to_cpu(es->s_state);
 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
 				goto restore_opts;
-			if (!ext4_setup_super (sb, es, 0))
+			if (!ext4_setup_super(sb, es, 0))
 				sb->s_flags &= ~MS_RDONLY;
 		}
 	}
@@ -3093,7 +3112,7 @@ restore_opts:
 	return err;
 }
 
-static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
+static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct super_block *sb = dentry->d_sb;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -3331,12 +3350,12 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 	}
 	/* Journaling quota? */
 	if (EXT4_SB(sb)->s_qf_names[type]) {
-		/* Quotafile not of fs root? */
+		/* Quotafile not in fs root? */
 		if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode)
 			printk(KERN_WARNING
 				"EXT4-fs: Quota file not on filesystem root. "
 				"Journaled quota will not work.\n");
- 	}
+	}
 
 	/*
 	 * When we journal data on quota file, we have to flush journal to see
@@ -3352,8 +3371,9 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 	}
 
+	err = vfs_quota_on_path(sb, type, format_id, &nd.path);
 	path_put(&nd.path);
-	return vfs_quota_on(sb, type, format_id, path, remount);
+	return err;
 }
 
 /* Read data from quotafile - avoid pagecache and such because we cannot afford
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 93c5fdcdad2..8954208b489 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1512,7 +1512,7 @@ static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
 	char *name = entry->e_name;
 	int n;
 
-	for (n=0; n < entry->e_name_len; n++) {
+	for (n = 0; n < entry->e_name_len; n++) {
 		hash = (hash << NAME_HASH_SHIFT) ^
 		       (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
 		       *name++;