Merge commit 'v2.6.32' into reiserfs/kill-bkl

Merge-reason: The tree was based 2.6.31. It's better to be up to date
with 2.6.32. Although no conflicting changes were made in between,
it gives benchmarking results closer to the lastest kernel behaviour.

1 files changed, 491 insertions, 79 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 73ebfb44ad7..715264b4bae 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -93,7 +93,9 @@ static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
 	ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
-static int ext4_ext_journal_restart(handle_t *handle, int needed)
+static int ext4_ext_truncate_extend_restart(handle_t *handle,
+					    struct inode *inode,
+					    int needed)
 {
 	int err;
 
@@ -104,7 +106,14 @@ static int ext4_ext_journal_restart(handle_t *handle, int needed)
 	err = ext4_journal_extend(handle, needed);
 	if (err <= 0)
 		return err;
-	return ext4_journal_restart(handle, needed);
+	err = ext4_truncate_restart_trans(handle, inode, needed);
+	/*
+	 * We have dropped i_data_sem so someone might have cached again
+	 * an extent we are going to truncate.
+	 */
+	ext4_ext_invalidate_cache(inode);
+
+	return err;
 }
 
 /*
@@ -220,57 +229,65 @@ ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
 	return newblock;
 }
 
-static int ext4_ext_space_block(struct inode *inode)
+static inline int ext4_ext_space_block(struct inode *inode, int check)
 {
 	int size;
 
 	size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 			/ sizeof(struct ext4_extent);
+	if (!check) {
 #ifdef AGGRESSIVE_TEST
-	if (size > 6)
-		size = 6;
+		if (size > 6)
+			size = 6;
 #endif
+	}
 	return size;
 }
 
-static int ext4_ext_space_block_idx(struct inode *inode)
+static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
 {
 	int size;
 
 	size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 			/ sizeof(struct ext4_extent_idx);
+	if (!check) {
 #ifdef AGGRESSIVE_TEST
-	if (size > 5)
-		size = 5;
+		if (size > 5)
+			size = 5;
 #endif
+	}
 	return size;
 }
 
-static int ext4_ext_space_root(struct inode *inode)
+static inline int ext4_ext_space_root(struct inode *inode, int check)
 {
 	int size;
 
 	size = sizeof(EXT4_I(inode)->i_data);
 	size -= sizeof(struct ext4_extent_header);
 	size /= sizeof(struct ext4_extent);
+	if (!check) {
 #ifdef AGGRESSIVE_TEST
-	if (size > 3)
-		size = 3;
+		if (size > 3)
+			size = 3;
 #endif
+	}
 	return size;
 }
 
-static int ext4_ext_space_root_idx(struct inode *inode)
+static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 {
 	int size;
 
 	size = sizeof(EXT4_I(inode)->i_data);
 	size -= sizeof(struct ext4_extent_header);
 	size /= sizeof(struct ext4_extent_idx);
+	if (!check) {
 #ifdef AGGRESSIVE_TEST
-	if (size > 4)
-		size = 4;
+		if (size > 4)
+			size = 4;
 #endif
+	}
 	return size;
 }
 
@@ -284,9 +301,9 @@ int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
 	int lcap, icap, rcap, leafs, idxs, num;
 	int newextents = blocks;
 
-	rcap = ext4_ext_space_root_idx(inode);
-	lcap = ext4_ext_space_block(inode);
-	icap = ext4_ext_space_block_idx(inode);
+	rcap = ext4_ext_space_root_idx(inode, 0);
+	lcap = ext4_ext_space_block(inode, 0);
+	icap = ext4_ext_space_block_idx(inode, 0);
 
 	/* number of new leaf blocks needed */
 	num = leafs = (newextents + lcap - 1) / lcap;
@@ -311,14 +328,14 @@ ext4_ext_max_entries(struct inode *inode, int depth)
 
 	if (depth == ext_depth(inode)) {
 		if (depth == 0)
-			max = ext4_ext_space_root(inode);
+			max = ext4_ext_space_root(inode, 1);
 		else
-			max = ext4_ext_space_root_idx(inode);
+			max = ext4_ext_space_root_idx(inode, 1);
 	} else {
 		if (depth == 0)
-			max = ext4_ext_space_block(inode);
+			max = ext4_ext_space_block(inode, 1);
 		else
-			max = ext4_ext_space_block_idx(inode);
+			max = ext4_ext_space_block_idx(inode, 1);
 	}
 
 	return max;
@@ -437,8 +454,9 @@ static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 		  ext_debug("  %d->%llu", le32_to_cpu(path->p_idx->ei_block),
 			    idx_pblock(path->p_idx));
 		} else if (path->p_ext) {
-			ext_debug("  %d:%d:%llu ",
+			ext_debug("  %d:[%d]%d:%llu ",
 				  le32_to_cpu(path->p_ext->ee_block),
+				  ext4_ext_is_uninitialized(path->p_ext),
 				  ext4_ext_get_actual_len(path->p_ext),
 				  ext_pblock(path->p_ext));
 		} else
@@ -460,8 +478,11 @@ static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
 	eh = path[depth].p_hdr;
 	ex = EXT_FIRST_EXTENT(eh);
 
+	ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
+
 	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
-		ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block),
+		ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
+			  ext4_ext_is_uninitialized(ex),
 			  ext4_ext_get_actual_len(ex), ext_pblock(ex));
 	}
 	ext_debug("\n");
@@ -580,9 +601,10 @@ ext4_ext_binsearch(struct inode *inode,
 	}
 
 	path->p_ext = l - 1;
-	ext_debug("  -> %d:%llu:%d ",
+	ext_debug("  -> %d:%llu:[%d]%d ",
 			le32_to_cpu(path->p_ext->ee_block),
 			ext_pblock(path->p_ext),
+			ext4_ext_is_uninitialized(path->p_ext),
 			ext4_ext_get_actual_len(path->p_ext));
 
 #ifdef CHECK_BINSEARCH
@@ -612,7 +634,7 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 	eh->eh_depth = 0;
 	eh->eh_entries = 0;
 	eh->eh_magic = EXT4_EXT_MAGIC;
-	eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode));
+	eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
 	ext4_mark_inode_dirty(handle, inode);
 	ext4_ext_invalidate_cache(inode);
 	return 0;
@@ -701,7 +723,7 @@ err:
  * insert new index [@logical;@ptr] into the block at @curp;
  * check where to insert: before @curp or after @curp
  */
-static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
+int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 				struct ext4_ext_path *curp,
 				int logical, ext4_fsblk_t ptr)
 {
@@ -837,7 +859,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 
 	neh = ext_block_hdr(bh);
 	neh->eh_entries = 0;
-	neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
+	neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
 	neh->eh_magic = EXT4_EXT_MAGIC;
 	neh->eh_depth = 0;
 	ex = EXT_FIRST_EXTENT(neh);
@@ -850,9 +872,10 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	path[depth].p_ext++;
 	while (path[depth].p_ext <=
 			EXT_MAX_EXTENT(path[depth].p_hdr)) {
-		ext_debug("move %d:%llu:%d in new leaf %llu\n",
+		ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
 				le32_to_cpu(path[depth].p_ext->ee_block),
 				ext_pblock(path[depth].p_ext),
+				ext4_ext_is_uninitialized(path[depth].p_ext),
 				ext4_ext_get_actual_len(path[depth].p_ext),
 				newblock);
 		/*memmove(ex++, path[depth].p_ext++,
@@ -912,7 +935,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		neh = ext_block_hdr(bh);
 		neh->eh_entries = cpu_to_le16(1);
 		neh->eh_magic = EXT4_EXT_MAGIC;
-		neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
+		neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
 		neh->eh_depth = cpu_to_le16(depth - i);
 		fidx = EXT_FIRST_INDEX(neh);
 		fidx->ei_block = border;
@@ -1037,9 +1060,9 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	/* old root could have indexes or leaves
 	 * so calculate e_max right way */
 	if (ext_depth(inode))
-	  neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
+		neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
 	else
-	  neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
+		neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
 	neh->eh_magic = EXT4_EXT_MAGIC;
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
@@ -1054,7 +1077,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 		goto out;
 
 	curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
-	curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
+	curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
 	curp->p_hdr->eh_entries = cpu_to_le16(1);
 	curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
 
@@ -1563,7 +1586,7 @@ out:
  */
 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 				struct ext4_ext_path *path,
-				struct ext4_extent *newext)
+				struct ext4_extent *newext, int flag)
 {
 	struct ext4_extent_header *eh;
 	struct ext4_extent *ex, *fex;
@@ -1579,10 +1602,13 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	BUG_ON(path[depth].p_hdr == NULL);
 
 	/* try to insert block into found extent and return */
-	if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
-		ext_debug("append %d block to %d:%d (from %llu)\n",
+	if (ex && (flag != EXT4_GET_BLOCKS_DIO_CREATE_EXT)
+		&& ext4_can_extents_be_merged(inode, ex, newext)) {
+		ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
+				ext4_ext_is_uninitialized(newext),
 				ext4_ext_get_actual_len(newext),
 				le32_to_cpu(ex->ee_block),
+				ext4_ext_is_uninitialized(ex),
 				ext4_ext_get_actual_len(ex), ext_pblock(ex));
 		err = ext4_ext_get_access(handle, inode, path + depth);
 		if (err)
@@ -1651,9 +1677,10 @@ has_space:
 
 	if (!nearex) {
 		/* there is no extent in this leaf, create first one */
-		ext_debug("first extent in the leaf: %d:%llu:%d\n",
+		ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n",
 				le32_to_cpu(newext->ee_block),
 				ext_pblock(newext),
+				ext4_ext_is_uninitialized(newext),
 				ext4_ext_get_actual_len(newext));
 		path[depth].p_ext = EXT_FIRST_EXTENT(eh);
 	} else if (le32_to_cpu(newext->ee_block)
@@ -1663,10 +1690,11 @@ has_space:
 			len = EXT_MAX_EXTENT(eh) - nearex;
 			len = (len - 1) * sizeof(struct ext4_extent);
 			len = len < 0 ? 0 : len;
-			ext_debug("insert %d:%llu:%d after: nearest 0x%p, "
+			ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, "
 					"move %d from 0x%p to 0x%p\n",
 					le32_to_cpu(newext->ee_block),
 					ext_pblock(newext),
+					ext4_ext_is_uninitialized(newext),
 					ext4_ext_get_actual_len(newext),
 					nearex, len, nearex + 1, nearex + 2);
 			memmove(nearex + 2, nearex + 1, len);
@@ -1676,10 +1704,11 @@ has_space:
 		BUG_ON(newext->ee_block == nearex->ee_block);
 		len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
 		len = len < 0 ? 0 : len;
-		ext_debug("insert %d:%llu:%d before: nearest 0x%p, "
+		ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, "
 				"move %d from 0x%p to 0x%p\n",
 				le32_to_cpu(newext->ee_block),
 				ext_pblock(newext),
+				ext4_ext_is_uninitialized(newext),
 				ext4_ext_get_actual_len(newext),
 				nearex, len, nearex + 1, nearex + 2);
 		memmove(nearex + 1, nearex, len);
@@ -1694,7 +1723,8 @@ has_space:
 
 merge:
 	/* try to merge extents to the right */
-	ext4_ext_try_to_merge(inode, path, nearex);
+	if (flag != EXT4_GET_BLOCKS_DIO_CREATE_EXT)
+		ext4_ext_try_to_merge(inode, path, nearex);
 
 	/* try to merge extents to the left */
 
@@ -2094,7 +2124,8 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 		else
 			uninitialized = 0;
 
-		ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len);
+		ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
+			 uninitialized, ex_ee_len);
 		path[depth].p_ext = ex;
 
 		a = ex_ee_block > start ? ex_ee_block : start;
@@ -2138,7 +2169,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 		}
 		credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
 
-		err = ext4_ext_journal_restart(handle, credits);
+		err = ext4_ext_truncate_extend_restart(handle, inode, credits);
 		if (err)
 			goto out;
 
@@ -2327,7 +2358,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
 		if (err == 0) {
 			ext_inode_hdr(inode)->eh_depth = 0;
 			ext_inode_hdr(inode)->eh_max =
-				cpu_to_le16(ext4_ext_space_root(inode));
+				cpu_to_le16(ext4_ext_space_root(inode, 0));
 			err = ext4_ext_dirty(handle, inode, path);
 		}
 	}
@@ -2349,6 +2380,7 @@ void ext4_ext_init(struct super_block *sb)
 	 */
 
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
+#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
 		printk(KERN_INFO "EXT4-fs: file extents enabled");
 #ifdef AGGRESSIVE_TEST
 		printk(", aggressive tests");
@@ -2360,6 +2392,7 @@ void ext4_ext_init(struct super_block *sb)
 		printk(", stats");
 #endif
 		printk("\n");
+#endif
 #ifdef EXTENTS_STATS
 		spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
 		EXT4_SB(sb)->s_ext_min = 1 << 30;
@@ -2461,7 +2494,6 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
 }
 
 #define EXT4_EXT_ZERO_LEN 7
-
 /*
  * This function is called by ext4_ext_get_blocks() if someone tries to write
  * to an uninitialized extent. It may result in splitting the uninitialized
@@ -2554,7 +2586,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 			ex3->ee_block = cpu_to_le32(iblock);
 			ext4_ext_store_pblock(ex3, newblock);
 			ex3->ee_len = cpu_to_le16(allocated);
-			err = ext4_ext_insert_extent(handle, inode, path, ex3);
+			err = ext4_ext_insert_extent(handle, inode, path,
+							ex3, 0);
 			if (err == -ENOSPC) {
 				err =  ext4_ext_zeroout(inode, &orig_ex);
 				if (err)
@@ -2610,7 +2643,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 		ext4_ext_store_pblock(ex3, newblock + max_blocks);
 		ex3->ee_len = cpu_to_le16(allocated - max_blocks);
 		ext4_ext_mark_uninitialized(ex3);
-		err = ext4_ext_insert_extent(handle, inode, path, ex3);
+		err = ext4_ext_insert_extent(handle, inode, path, ex3, 0);
 		if (err == -ENOSPC) {
 			err =  ext4_ext_zeroout(inode, &orig_ex);
 			if (err)
@@ -2728,7 +2761,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 	err = ext4_ext_dirty(handle, inode, path + depth);
 	goto out;
 insert:
-	err = ext4_ext_insert_extent(handle, inode, path, &newex);
+	err = ext4_ext_insert_extent(handle, inode, path, &newex, 0);
 	if (err == -ENOSPC) {
 		err =  ext4_ext_zeroout(inode, &orig_ex);
 		if (err)
@@ -2743,6 +2776,7 @@ insert:
 	} else if (err)
 		goto fix_extent_len;
 out:
+	ext4_ext_show_leaf(inode, path);
 	return err ? err : allocated;
 
 fix_extent_len:
@@ -2755,6 +2789,331 @@ fix_extent_len:
 }
 
 /*
+ * This function is called by ext4_ext_get_blocks() from
+ * ext4_get_blocks_dio_write() when DIO to write
+ * to an uninitialized extent.
+ *
+ * Writing to an uninitized extent may result in splitting the uninitialized
+ * extent into multiple /intialized unintialized extents (up to three)
+ * There are three possibilities:
+ *   a> There is no split required: Entire extent should be uninitialized
+ *   b> Splits in two extents: Write is happening at either end of the extent
+ *   c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * One of more index blocks maybe needed if the extent tree grow after
+ * the unintialized extent split. To prevent ENOSPC occur at the IO
+ * complete, we need to split the uninitialized extent before DIO submit
+ * the IO. The uninitilized extent called at this time will be split
+ * into three uninitialized extent(at most). After IO complete, the part
+ * being filled will be convert to initialized by the end_io callback function
+ * via ext4_convert_unwritten_extents().
+ *
+ * Returns the size of uninitialized extent to be written on success.
+ */
+static int ext4_split_unwritten_extents(handle_t *handle,
+					struct inode *inode,
+					struct ext4_ext_path *path,
+					ext4_lblk_t iblock,
+					unsigned int max_blocks,
+					int flags)
+{
+	struct ext4_extent *ex, newex, orig_ex;
+	struct ext4_extent *ex1 = NULL;
+	struct ext4_extent *ex2 = NULL;
+	struct ext4_extent *ex3 = NULL;
+	struct ext4_extent_header *eh;
+	ext4_lblk_t ee_block;
+	unsigned int allocated, ee_len, depth;
+	ext4_fsblk_t newblock;
+	int err = 0;
+
+	ext_debug("ext4_split_unwritten_extents: inode %lu,"
+		  "iblock %llu, max_blocks %u\n", inode->i_ino,
+		  (unsigned long long)iblock, max_blocks);
+	depth = ext_depth(inode);
+	eh = path[depth].p_hdr;
+	ex = path[depth].p_ext;
+	ee_block = le32_to_cpu(ex->ee_block);
+	ee_len = ext4_ext_get_actual_len(ex);
+	allocated = ee_len - (iblock - ee_block);
+	newblock = iblock - ee_block + ext_pblock(ex);
+	ex2 = ex;
+	orig_ex.ee_block = ex->ee_block;
+	orig_ex.ee_len   = cpu_to_le16(ee_len);
+	ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
+
+	/*
+ 	 * If the uninitialized extent begins at the same logical
+ 	 * block where the write begins, and the write completely
+ 	 * covers the extent, then we don't need to split it.
+ 	 */
+	if ((iblock == ee_block) && (allocated <= max_blocks))
+		return allocated;
+
+	err = ext4_ext_get_access(handle, inode, path + depth);
+	if (err)
+		goto out;
+	/* ex1: ee_block to iblock - 1 : uninitialized */
+	if (iblock > ee_block) {
+		ex1 = ex;
+		ex1->ee_len = cpu_to_le16(iblock - ee_block);
+		ext4_ext_mark_uninitialized(ex1);
+		ex2 = &newex;
+	}
+	/*
+	 * for sanity, update the length of the ex2 extent before
+	 * we insert ex3, if ex1 is NULL. This is to avoid temporary
+	 * overlap of blocks.
+	 */
+	if (!ex1 && allocated > max_blocks)
+		ex2->ee_len = cpu_to_le16(max_blocks);
+	/* ex3: to ee_block + ee_len : uninitialised */
+	if (allocated > max_blocks) {
+		unsigned int newdepth;
+		ex3 = &newex;
+		ex3->ee_block = cpu_to_le32(iblock + max_blocks);
+		ext4_ext_store_pblock(ex3, newblock + max_blocks);
+		ex3->ee_len = cpu_to_le16(allocated - max_blocks);
+		ext4_ext_mark_uninitialized(ex3);
+		err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
+		if (err == -ENOSPC) {
+			err =  ext4_ext_zeroout(inode, &orig_ex);
+			if (err)
+				goto fix_extent_len;
+			/* update the extent length and mark as initialized */
+			ex->ee_block = orig_ex.ee_block;
+			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)
+			goto fix_extent_len;
+		/*
+		 * The depth, and hence eh & ex might change
+		 * as part of the insert above.
+		 */
+		newdepth = ext_depth(inode);
+		/*
+		 * update the extent length after successful insert of the
+		 * split extent
+		 */
+		orig_ex.ee_len = cpu_to_le16(ee_len -
+						ext4_ext_get_actual_len(ex3));
+		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 there was a change of depth as part of the
+	 * insertion of ex3 above, we need to update the length
+	 * of the ex1 extent again here
+	 */
+	if (ex1 && ex1 != ex) {
+		ex1 = ex;
+		ex1->ee_len = cpu_to_le16(iblock - ee_block);
+		ext4_ext_mark_uninitialized(ex1);
+		ex2 = &newex;
+	}
+	/*
+	 * ex2: iblock to iblock + maxblocks-1 : to be direct IO written,
+	 * uninitialised still.
+	 */
+	ex2->ee_block = cpu_to_le32(iblock);
+	ext4_ext_store_pblock(ex2, newblock);
+	ex2->ee_len = cpu_to_le16(allocated);
+	ext4_ext_mark_uninitialized(ex2);
+	if (ex2 != ex)
+		goto insert;
+	/* Mark modified extent as dirty */
+	err = ext4_ext_dirty(handle, inode, path + depth);
+	ext_debug("out here\n");
+	goto out;
+insert:
+	err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+	if (err == -ENOSPC) {
+		err =  ext4_ext_zeroout(inode, &orig_ex);
+		if (err)
+			goto fix_extent_len;
+		/* update the extent length and mark as initialized */
+		ex->ee_block = orig_ex.ee_block;
+		ex->ee_len   = orig_ex.ee_len;
+		ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+		ext4_ext_dirty(handle, inode, path + depth);
+		/* zero out the first half */
+		return allocated;
+	} else if (err)
+		goto fix_extent_len;
+out:
+	ext4_ext_show_leaf(inode, path);
+	return err ? err : allocated;
+
+fix_extent_len:
+	ex->ee_block = orig_ex.ee_block;
+	ex->ee_len   = orig_ex.ee_len;
+	ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+	ext4_ext_mark_uninitialized(ex);
+	ext4_ext_dirty(handle, inode, path + depth);
+	return err;
+}
+static int ext4_convert_unwritten_extents_dio(handle_t *handle,
+					      struct inode *inode,
+					      struct ext4_ext_path *path)
+{
+	struct ext4_extent *ex;
+	struct ext4_extent_header *eh;
+	int depth;
+	int err = 0;
+	int ret = 0;
+
+	depth = ext_depth(inode);
+	eh = path[depth].p_hdr;
+	ex = path[depth].p_ext;
+
+	err = ext4_ext_get_access(handle, inode, path + depth);
+	if (err)
+		goto out;
+	/* first mark the extent as initialized */
+	ext4_ext_mark_initialized(ex);
+
+	/*
+	 * We have to see if it can be merged with the extent
+	 * on the left.
+	 */
+	if (ex > EXT_FIRST_EXTENT(eh)) {
+		/*
+		 * To merge left, pass "ex - 1" to try_to_merge(),
+		 * since it merges towards right _only_.
+		 */
+		ret = ext4_ext_try_to_merge(inode, path, ex - 1);
+		if (ret) {
+			err = ext4_ext_correct_indexes(handle, inode, path);
+			if (err)
+				goto out;
+			depth = ext_depth(inode);
+			ex--;
+		}
+	}
+	/*
+	 * Try to Merge towards right.
+	 */
+	ret = ext4_ext_try_to_merge(inode, path, ex);
+	if (ret) {
+		err = ext4_ext_correct_indexes(handle, inode, path);
+		if (err)
+			goto out;
+		depth = ext_depth(inode);
+	}
+	/* Mark modified extent as dirty */
+	err = ext4_ext_dirty(handle, inode, path + depth);
+out:
+	ext4_ext_show_leaf(inode, path);
+	return err;
+}
+
+static int
+ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
+			ext4_lblk_t iblock, unsigned int max_blocks,
+			struct ext4_ext_path *path, int flags,
+			unsigned int allocated, struct buffer_head *bh_result,
+			ext4_fsblk_t newblock)
+{
+	int ret = 0;
+	int err = 0;
+	ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+
+	ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
+		  "block %llu, max_blocks %u, flags %d, allocated %u",
+		  inode->i_ino, (unsigned long long)iblock, max_blocks,
+		  flags, allocated);
+	ext4_ext_show_leaf(inode, path);
+
+	/* DIO get_block() before submit the IO, split the extent */
+	if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
+		ret = ext4_split_unwritten_extents(handle,
+						inode, path, iblock,
+						max_blocks, flags);
+		/*
+		 * Flag the inode(non aio case) or end_io struct (aio case)
+		 * that this IO needs to convertion to written when IO is
+		 * completed
+		 */
+		if (io)
+			io->flag = DIO_AIO_UNWRITTEN;
+		else
+			EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;
+		goto out;
+	}
+	/* async DIO end_io complete, convert the filled extent to written */
+	if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) {
+		ret = ext4_convert_unwritten_extents_dio(handle, inode,
+							path);
+		goto out2;
+	}
+	/* buffered IO case */
+	/*
+	 * repeat fallocate creation request
+	 * we already have an unwritten extent
+	 */
+	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
+		goto map_out;
+
+	/* buffered READ or buffered write_begin() lookup */
+	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+		/*
+		 * We have blocks reserved already.  We
+		 * return allocated blocks so that delalloc
+		 * won't do block reservation for us.  But
+		 * the buffer head will be unmapped so that
+		 * a read from the block returns 0s.
+		 */
+		set_buffer_unwritten(bh_result);
+		goto out1;
+	}
+
+	/* buffered write, writepage time, convert*/
+	ret = ext4_ext_convert_to_initialized(handle, inode,
+						path, iblock,
+						max_blocks);
+out:
+	if (ret <= 0) {
+		err = ret;
+		goto out2;
+	} else
+		allocated = ret;
+	set_buffer_new(bh_result);
+map_out:
+	set_buffer_mapped(bh_result);
+out1:
+	if (allocated > max_blocks)
+		allocated = max_blocks;
+	ext4_ext_show_leaf(inode, path);
+	bh_result->b_bdev = inode->i_sb->s_bdev;
+	bh_result->b_blocknr = newblock;
+out2:
+	if (path) {
+		ext4_ext_drop_refs(path);
+		kfree(path);
+	}
+	return err ? err : allocated;
+}
+/*
  * Block allocation/map/preallocation routine for extents based files
  *
  *
@@ -2784,9 +3143,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	int err = 0, depth, ret, cache_type;
 	unsigned int allocated = 0;
 	struct ext4_allocation_request ar;
+	ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
 
 	__clear_bit(BH_New, &bh_result->b_state);
-	ext_debug("blocks %u/%u requested for inode %u\n",
+	ext_debug("blocks %u/%u requested for inode %lu\n",
 			iblock, max_blocks, inode->i_ino);
 
 	/* check in cache */
@@ -2849,7 +3209,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 			newblock = iblock - ee_block + ee_start;
 			/* number of remaining blocks in the extent */
 			allocated = ee_len - (iblock - ee_block);
-			ext_debug("%u fit into %lu:%d -> %llu\n", iblock,
+			ext_debug("%u fit into %u:%d -> %llu\n", iblock,
 					ee_block, ee_len, newblock);
 
 			/* Do not put uninitialized extent in the cache */
@@ -2859,33 +3219,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 							EXT4_EXT_CACHE_EXTENT);
 				goto out;
 			}
-			if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
-				goto out;
-			if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
-				if (allocated > max_blocks)
-					allocated = max_blocks;
-				/*
-				 * We have blocks reserved already.  We
-				 * return allocated blocks so that delalloc
-				 * won't do block reservation for us.  But
-				 * the buffer head will be unmapped so that
-				 * a read from the block returns 0s.
-				 */
-				set_buffer_unwritten(bh_result);
-				bh_result->b_bdev = inode->i_sb->s_bdev;
-				bh_result->b_blocknr = newblock;
-				goto out2;
-			}
-
-			ret = ext4_ext_convert_to_initialized(handle, inode,
-								path, iblock,
-								max_blocks);
-			if (ret <= 0) {
-				err = ret;
-				goto out2;
-			} else
-				allocated = ret;
-			goto outnew;
+			ret = ext4_ext_handle_uninitialized_extents(handle,
+					inode, iblock, max_blocks, path,
+					flags, allocated, bh_result, newblock);
+			return ret;
 		}
 	}
 
@@ -2950,15 +3287,33 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	newblock = ext4_mb_new_blocks(handle, &ar, &err);
 	if (!newblock)
 		goto out2;
-	ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
+	ext_debug("allocate new block: goal %llu, found %llu/%u\n",
 		  ar.goal, newblock, allocated);
 
 	/* try to insert new extent into found leaf and return */
 	ext4_ext_store_pblock(&newex, newblock);
 	newex.ee_len = cpu_to_le16(ar.len);
-	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)  /* Mark uninitialized */
+	/* Mark uninitialized */
+	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
 		ext4_ext_mark_uninitialized(&newex);
-	err = ext4_ext_insert_extent(handle, inode, path, &newex);
+		/*
+		 * io_end structure was created for every async
+		 * direct IO write to the middle of the file.
+		 * To avoid unecessary convertion for every aio dio rewrite
+		 * to the mid of file, here we flag the IO that is really
+		 * need the convertion.
+		 * For non asycn direct IO case, flag the inode state
+		 * that we need to perform convertion when IO is done.
+		 */
+		if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
+			if (io)
+				io->flag = DIO_AIO_UNWRITTEN;
+			else
+				EXT4_I(inode)->i_state |=
+					EXT4_STATE_DIO_UNWRITTEN;;
+		}
+	}
+	err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
 	if (err) {
 		/* free data blocks we just allocated */
 		/* not a good idea to call discard here directly,
@@ -2972,7 +3327,6 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	/* previous routine could use block we allocated */
 	newblock = ext_pblock(&newex);
 	allocated = ext4_ext_get_actual_len(&newex);
-outnew:
 	set_buffer_new(bh_result);
 
 	/* Cache only when it is _not_ an uninitialized extent */
@@ -3171,6 +3525,64 @@ retry:
 }
 
 /*
+ * This function convert a range of blocks to written extents
+ * The caller of this function will pass the start offset and the size.
+ * all unwritten extents within this range will be converted to
+ * written extents.
+ *
+ * This function is called from the direct IO end io call back
+ * function, to convert the fallocated extents after IO is completed.
+ * Returns 0 on success.
+ */
+int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
+				    loff_t len)
+{
+	handle_t *handle;
+	ext4_lblk_t block;
+	unsigned int max_blocks;
+	int ret = 0;
+	int ret2 = 0;
+	struct buffer_head map_bh;
+	unsigned int credits, blkbits = inode->i_blkbits;
+
+	block = offset >> blkbits;
+	/*
+	 * We can't just convert len to max_blocks because
+	 * If blocksize = 4096 offset = 3072 and len = 2048
+	 */
+	max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
+							- block;
+	/*
+	 * credits to insert 1 extent into extent tree
+	 */
+	credits = ext4_chunk_trans_blocks(inode, max_blocks);
+	while (ret >= 0 && ret < max_blocks) {
+		block = block + ret;
+		max_blocks = max_blocks - ret;
+		handle = ext4_journal_start(inode, credits);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
+			break;
+		}
+		map_bh.b_state = 0;
+		ret = ext4_get_blocks(handle, inode, block,
+				      max_blocks, &map_bh,
+				      EXT4_GET_BLOCKS_DIO_CONVERT_EXT);
+		if (ret <= 0) {
+			WARN_ON(ret <= 0);
+			printk(KERN_ERR "%s: ext4_ext_get_blocks "
+				    "returned error inode#%lu, block=%u, "
+				    "max_blocks=%u", __func__,
+				    inode->i_ino, block, max_blocks);
+		}
+		ext4_mark_inode_dirty(handle, inode);
+		ret2 = ext4_journal_stop(handle);
+		if (ret <= 0 || ret2 )
+			break;
+	}
+	return ret > 0 ? ret2 : ret;
+}
+/*
  * Callback function called for each extent to gather FIEMAP information.
  */
 static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path,