1 files changed, 883 insertions, 285 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 57cf568a98a..61fa9e1614a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -42,7 +42,6 @@
 #include <asm/uaccess.h>
 #include <linux/fiemap.h>
 #include "ext4_jbd2.h"
-#include "ext4_extents.h"
 
 #include <trace/events/ext4.h>
 
@@ -96,13 +95,17 @@ static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
  *  - ENOMEM
  *  - EIO
  */
-static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
-				struct ext4_ext_path *path)
+#define ext4_ext_dirty(handle, inode, path) \
+		__ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
+static int __ext4_ext_dirty(const char *where, unsigned int line,
+			    handle_t *handle, struct inode *inode,
+			    struct ext4_ext_path *path)
 {
 	int err;
 	if (path->p_bh) {
 		/* path points to block */
-		err = ext4_handle_dirty_metadata(handle, inode, path->p_bh);
+		err = __ext4_handle_dirty_metadata(where, line, handle,
+						   inode, path->p_bh);
 	} else {
 		/* path points to leaf/index in inode body */
 		err = ext4_mark_inode_dirty(handle, inode);
@@ -114,11 +117,9 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
 			      struct ext4_ext_path *path,
 			      ext4_lblk_t block)
 {
-	int depth;
-
 	if (path) {
+		int depth = path->p_depth;
 		struct ext4_extent *ex;
-		depth = path->p_depth;
 
 		/*
 		 * Try to predict block placement assuming that we are
@@ -180,12 +181,10 @@ static inline int ext4_ext_space_block(struct inode *inode, int check)
 
 	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 (!check && size > 6)
+		size = 6;
 #endif
-	}
 	return size;
 }
 
@@ -195,12 +194,10 @@ static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
 
 	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 (!check && size > 5)
+		size = 5;
 #endif
-	}
 	return size;
 }
 
@@ -211,12 +208,10 @@ static inline int ext4_ext_space_root(struct inode *inode, int check)
 	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 (!check && size > 3)
+		size = 3;
 #endif
-	}
 	return size;
 }
 
@@ -227,12 +222,10 @@ static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 	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 (!check && size > 4)
+		size = 4;
 #endif
-	}
 	return size;
 }
 
@@ -244,7 +237,7 @@ static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	int idxs, num = 0;
+	int idxs;
 
 	idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 		/ sizeof(struct ext4_extent_idx));
@@ -259,6 +252,8 @@ int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
 	 */
 	if (ei->i_da_metadata_calc_len &&
 	    ei->i_da_metadata_calc_last_lblock+1 == lblock) {
+		int num = 0;
+
 		if ((ei->i_da_metadata_calc_len % idxs) == 0)
 			num++;
 		if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
@@ -321,8 +316,6 @@ static int ext4_valid_extent_entries(struct inode *inode,
 				struct ext4_extent_header *eh,
 				int depth)
 {
-	struct ext4_extent *ext;
-	struct ext4_extent_idx *ext_idx;
 	unsigned short entries;
 	if (eh->eh_entries == 0)
 		return 1;
@@ -331,7 +324,7 @@ static int ext4_valid_extent_entries(struct inode *inode,
 
 	if (depth == 0) {
 		/* leaf entries */
-		ext = EXT_FIRST_EXTENT(eh);
+		struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
 		while (entries) {
 			if (!ext4_valid_extent(inode, ext))
 				return 0;
@@ -339,7 +332,7 @@ static int ext4_valid_extent_entries(struct inode *inode,
 			entries--;
 		}
 	} else {
-		ext_idx = EXT_FIRST_INDEX(eh);
+		struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
 		while (entries) {
 			if (!ext4_valid_extent_idx(inode, ext_idx))
 				return 0;
@@ -751,31 +744,30 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		return -EIO;
 	}
 
-	len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
 	if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
 		/* insert after */
-		if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
-			len = (len - 1) * sizeof(struct ext4_extent_idx);
-			len = len < 0 ? 0 : len;
-			ext_debug("insert new index %d after: %llu. "
-					"move %d from 0x%p to 0x%p\n",
-					logical, ptr, len,
-					(curp->p_idx + 1), (curp->p_idx + 2));
-			memmove(curp->p_idx + 2, curp->p_idx + 1, len);
-		}
+		ext_debug("insert new index %d after: %llu\n", logical, ptr);
 		ix = curp->p_idx + 1;
 	} else {
 		/* insert before */
-		len = len * sizeof(struct ext4_extent_idx);
-		len = len < 0 ? 0 : len;
-		ext_debug("insert new index %d before: %llu. "
-				"move %d from 0x%p to 0x%p\n",
-				logical, ptr, len,
-				curp->p_idx, (curp->p_idx + 1));
-		memmove(curp->p_idx + 1, curp->p_idx, len);
+		ext_debug("insert new index %d before: %llu\n", logical, ptr);
 		ix = curp->p_idx;
 	}
 
+	len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
+	BUG_ON(len < 0);
+	if (len > 0) {
+		ext_debug("insert new index %d: "
+				"move %d indices from 0x%p to 0x%p\n",
+				logical, len, ix, ix + 1);
+		memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
+	}
+
+	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+		return -EIO;
+	}
+
 	ix->ei_block = cpu_to_le32(logical);
 	ext4_idx_store_pblock(ix, ptr);
 	le16_add_cpu(&curp->p_hdr->eh_entries, 1);
@@ -1042,16 +1034,14 @@ cleanup:
  */
 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 				 unsigned int flags,
-				 struct ext4_ext_path *path,
 				 struct ext4_extent *newext)
 {
-	struct ext4_ext_path *curp = path;
 	struct ext4_extent_header *neh;
 	struct buffer_head *bh;
 	ext4_fsblk_t newblock;
 	int err = 0;
 
-	newblock = ext4_ext_new_meta_block(handle, inode, path,
+	newblock = ext4_ext_new_meta_block(handle, inode, NULL,
 		newext, &err, flags);
 	if (newblock == 0)
 		return err;
@@ -1071,7 +1061,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	}
 
 	/* move top-level index/leaf into new block */
-	memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
+	memmove(bh->b_data, EXT4_I(inode)->i_data,
+		sizeof(EXT4_I(inode)->i_data));
 
 	/* set size of new block */
 	neh = ext_block_hdr(bh);
@@ -1089,32 +1080,23 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	if (err)
 		goto out;
 
-	/* create index in new top-level index: num,max,pointer */
-	err = ext4_ext_get_access(handle, inode, curp);
-	if (err)
-		goto out;
-
-	curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
-	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);
-
-	if (path[0].p_hdr->eh_depth)
-		curp->p_idx->ei_block =
-			EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
-	else
-		curp->p_idx->ei_block =
-			EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
-	ext4_idx_store_pblock(curp->p_idx, newblock);
-
+	/* Update top-level index: num,max,pointer */
 	neh = ext_inode_hdr(inode);
+	neh->eh_entries = cpu_to_le16(1);
+	ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
+	if (neh->eh_depth == 0) {
+		/* Root extent block becomes index block */
+		neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
+		EXT_FIRST_INDEX(neh)->ei_block =
+			EXT_FIRST_EXTENT(neh)->ee_block;
+	}
 	ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
 		  le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
 		  le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
 		  ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
 
-	neh->eh_depth = cpu_to_le16(path->p_depth + 1);
-	err = ext4_ext_dirty(handle, inode, curp);
+	neh->eh_depth = cpu_to_le16(neh->eh_depth + 1);
+	ext4_mark_inode_dirty(handle, inode);
 out:
 	brelse(bh);
 
@@ -1162,8 +1144,7 @@ repeat:
 			err = PTR_ERR(path);
 	} else {
 		/* tree is full, time to grow in depth */
-		err = ext4_ext_grow_indepth(handle, inode, flags,
-					    path, newext);
+		err = ext4_ext_grow_indepth(handle, inode, flags, newext);
 		if (err)
 			goto out;
 
@@ -1235,9 +1216,9 @@ static int ext4_ext_search_left(struct inode *inode,
 			if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
 				EXT4_ERROR_INODE(inode,
 				  "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
-				  ix != NULL ? ix->ei_block : 0,
+				  ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
 				  EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
-				    EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block : 0,
+		le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
 				  depth);
 				return -EIO;
 			}
@@ -1260,13 +1241,14 @@ static int ext4_ext_search_left(struct inode *inode,
 /*
  * search the closest allocated block to the right for *logical
  * and returns it at @logical + it's physical address at @phys
- * if *logical is the smallest allocated block, the function
+ * if *logical is the largest allocated block, the function
  * returns 0 at @phys
  * return value contains 0 (success) or error code
  */
 static int ext4_ext_search_right(struct inode *inode,
 				 struct ext4_ext_path *path,
-				 ext4_lblk_t *logical, ext4_fsblk_t *phys)
+				 ext4_lblk_t *logical, ext4_fsblk_t *phys,
+				 struct ext4_extent **ret_ex)
 {
 	struct buffer_head *bh = NULL;
 	struct ext4_extent_header *eh;
@@ -1308,9 +1290,7 @@ static int ext4_ext_search_right(struct inode *inode,
 				return -EIO;
 			}
 		}
-		*logical = le32_to_cpu(ex->ee_block);
-		*phys = ext4_ext_pblock(ex);
-		return 0;
+		goto found_extent;
 	}
 
 	if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
@@ -1323,9 +1303,7 @@ static int ext4_ext_search_right(struct inode *inode,
 	if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
 		/* next allocated block in this leaf */
 		ex++;
-		*logical = le32_to_cpu(ex->ee_block);
-		*phys = ext4_ext_pblock(ex);
-		return 0;
+		goto found_extent;
 	}
 
 	/* go up and search for index to the right */
@@ -1368,9 +1346,12 @@ got_index:
 		return -EIO;
 	}
 	ex = EXT_FIRST_EXTENT(eh);
+found_extent:
 	*logical = le32_to_cpu(ex->ee_block);
 	*phys = ext4_ext_pblock(ex);
-	put_bh(bh);
+	*ret_ex = ex;
+	if (bh)
+		put_bh(bh);
 	return 0;
 }
 
@@ -1395,7 +1376,8 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path)
 	while (depth >= 0) {
 		if (depth == path->p_depth) {
 			/* leaf */
-			if (path[depth].p_ext !=
+			if (path[depth].p_ext &&
+				path[depth].p_ext !=
 					EXT_LAST_EXTENT(path[depth].p_hdr))
 			  return le32_to_cpu(path[depth].p_ext[1].ee_block);
 		} else {
@@ -1623,7 +1605,8 @@ static int ext4_ext_try_to_merge(struct inode *inode,
  * such that there will be no overlap, and then returns 1.
  * If there is no overlap found, it returns 0.
  */
-static unsigned int ext4_ext_check_overlap(struct inode *inode,
+static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
+					   struct inode *inode,
 					   struct ext4_extent *newext,
 					   struct ext4_ext_path *path)
 {
@@ -1637,6 +1620,7 @@ static unsigned int ext4_ext_check_overlap(struct inode *inode,
 	if (!path[depth].p_ext)
 		goto out;
 	b2 = le32_to_cpu(path[depth].p_ext->ee_block);
+	b2 &= ~(sbi->s_cluster_ratio - 1);
 
 	/*
 	 * get the next allocated block if the extent in the path
@@ -1646,6 +1630,7 @@ static unsigned int ext4_ext_check_overlap(struct inode *inode,
 		b2 = ext4_ext_next_allocated_block(path);
 		if (b2 == EXT_MAX_BLOCKS)
 			goto out;
+		b2 &= ~(sbi->s_cluster_ratio - 1);
 	}
 
 	/* check for wrap through zero on extent logical start block*/
@@ -1697,7 +1682,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	/* try to insert block into found extent and return */
 	if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
 		&& ext4_can_extents_be_merged(inode, ex, newext)) {
-		ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
+		ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
 			  ext4_ext_is_uninitialized(newext),
 			  ext4_ext_get_actual_len(newext),
 			  le32_to_cpu(ex->ee_block),
@@ -1735,7 +1720,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
 		next = ext4_ext_next_leaf_block(path);
 	if (next != EXT_MAX_BLOCKS) {
-		ext_debug("next leaf block - %d\n", next);
+		ext_debug("next leaf block - %u\n", next);
 		BUG_ON(npath != NULL);
 		npath = ext4_ext_find_extent(inode, next, NULL);
 		if (IS_ERR(npath))
@@ -1773,46 +1758,51 @@ has_space:
 
 	if (!nearex) {
 		/* there is no extent in this leaf, create first one */
-		ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n",
+		ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
 				le32_to_cpu(newext->ee_block),
 				ext4_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)
+		nearex = EXT_FIRST_EXTENT(eh);
+	} else {
+		if (le32_to_cpu(newext->ee_block)
 			   > le32_to_cpu(nearex->ee_block)) {
-/*		BUG_ON(newext->ee_block == nearex->ee_block); */
-		if (nearex != EXT_LAST_EXTENT(eh)) {
-			len = EXT_MAX_EXTENT(eh) - nearex;
-			len = (len - 1) * sizeof(struct ext4_extent);
-			len = len < 0 ? 0 : len;
-			ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, "
-					"move %d from 0x%p to 0x%p\n",
+			/* Insert after */
+			ext_debug("insert %u:%llu:[%d]%d before: "
+					"nearest %p\n",
 					le32_to_cpu(newext->ee_block),
 					ext4_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);
+					nearex);
+			nearex++;
+		} else {
+			/* Insert before */
+			BUG_ON(newext->ee_block == nearex->ee_block);
+			ext_debug("insert %u:%llu:[%d]%d after: "
+					"nearest %p\n",
+					le32_to_cpu(newext->ee_block),
+					ext4_ext_pblock(newext),
+					ext4_ext_is_uninitialized(newext),
+					ext4_ext_get_actual_len(newext),
+					nearex);
+		}
+		len = EXT_LAST_EXTENT(eh) - nearex + 1;
+		if (len > 0) {
+			ext_debug("insert %u:%llu:[%d]%d: "
+					"move %d extents from 0x%p to 0x%p\n",
+					le32_to_cpu(newext->ee_block),
+					ext4_ext_pblock(newext),
+					ext4_ext_is_uninitialized(newext),
+					ext4_ext_get_actual_len(newext),
+					len, nearex, nearex + 1);
+			memmove(nearex + 1, nearex,
+				len * sizeof(struct ext4_extent));
 		}
-		path[depth].p_ext = nearex + 1;
-	} else {
-		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]%d before: nearest 0x%p, "
-				"move %d from 0x%p to 0x%p\n",
-				le32_to_cpu(newext->ee_block),
-				ext4_ext_pblock(newext),
-				ext4_ext_is_uninitialized(newext),
-				ext4_ext_get_actual_len(newext),
-				nearex, len, nearex, nearex + 1);
-		memmove(nearex + 1, nearex, len);
-		path[depth].p_ext = nearex;
 	}
 
 	le16_add_cpu(&eh->eh_entries, 1);
-	nearex = path[depth].p_ext;
+	path[depth].p_ext = nearex;
 	nearex->ee_block = newext->ee_block;
 	ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
 	nearex->ee_len = newext->ee_len;
@@ -1962,6 +1952,7 @@ ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
 	struct ext4_ext_cache *cex;
 	BUG_ON(len == 0);
 	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+	trace_ext4_ext_put_in_cache(inode, block, len, start);
 	cex = &EXT4_I(inode)->i_cached_extent;
 	cex->ec_block = block;
 	cex->ec_len = len;
@@ -2063,6 +2054,7 @@ errout:
 		sbi->extent_cache_misses++;
 	else
 		sbi->extent_cache_hits++;
+	trace_ext4_ext_in_cache(inode, block, ret);
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 	return ret;
 }
@@ -2130,6 +2122,8 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
 	if (err)
 		return err;
 	ext_debug("index is empty, remove it, free block %llu\n", leaf);
+	trace_ext4_ext_rm_idx(inode, leaf);
+
 	ext4_free_blocks(handle, inode, NULL, leaf, 1,
 			 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
 	return err;
@@ -2158,7 +2152,7 @@ int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
 			 *  need to account for leaf block credit
 			 *
 			 *  bitmaps and block group descriptor blocks
-			 *  and other metadat blocks still need to be
+			 *  and other metadata blocks still need to be
 			 *  accounted.
 			 */
 			/* 1 bitmap, 1 block group descriptor */
@@ -2195,14 +2189,40 @@ int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
 }
 
 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
-				struct ext4_extent *ex,
-				ext4_lblk_t from, ext4_lblk_t to)
+			      struct ext4_extent *ex,
+			      ext4_fsblk_t *partial_cluster,
+			      ext4_lblk_t from, ext4_lblk_t to)
 {
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	unsigned short ee_len =  ext4_ext_get_actual_len(ex);
+	ext4_fsblk_t pblk;
 	int flags = EXT4_FREE_BLOCKS_FORGET;
 
 	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
 		flags |= EXT4_FREE_BLOCKS_METADATA;
+	/*
+	 * For bigalloc file systems, we never free a partial cluster
+	 * at the beginning of the extent.  Instead, we make a note
+	 * that we tried freeing the cluster, and check to see if we
+	 * need to free it on a subsequent call to ext4_remove_blocks,
+	 * or at the end of the ext4_truncate() operation.
+	 */
+	flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
+
+	trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
+	/*
+	 * If we have a partial cluster, and it's different from the
+	 * cluster of the last block, we need to explicitly free the
+	 * partial cluster here.
+	 */
+	pblk = ext4_ext_pblock(ex) + ee_len - 1;
+	if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
+		ext4_free_blocks(handle, inode, NULL,
+				 EXT4_C2B(sbi, *partial_cluster),
+				 sbi->s_cluster_ratio, flags);
+		*partial_cluster = 0;
+	}
+
 #ifdef EXTENTS_STATS
 	{
 		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -2222,12 +2242,24 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 	    && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
 		/* tail removal */
 		ext4_lblk_t num;
-		ext4_fsblk_t start;
 
 		num = le32_to_cpu(ex->ee_block) + ee_len - from;
-		start = ext4_ext_pblock(ex) + ee_len - num;
-		ext_debug("free last %u blocks starting %llu\n", num, start);
-		ext4_free_blocks(handle, inode, NULL, start, num, flags);
+		pblk = ext4_ext_pblock(ex) + ee_len - num;
+		ext_debug("free last %u blocks starting %llu\n", num, pblk);
+		ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
+		/*
+		 * If the block range to be freed didn't start at the
+		 * beginning of a cluster, and we removed the entire
+		 * extent, save the partial cluster here, since we
+		 * might need to delete if we determine that the
+		 * truncate operation has removed all of the blocks in
+		 * the cluster.
+		 */
+		if (pblk & (sbi->s_cluster_ratio - 1) &&
+		    (ee_len == num))
+			*partial_cluster = EXT4_B2C(sbi, pblk);
+		else
+			*partial_cluster = 0;
 	} else if (from == le32_to_cpu(ex->ee_block)
 		   && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
 		/* head removal */
@@ -2238,7 +2270,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 		start = ext4_ext_pblock(ex);
 
 		ext_debug("free first %u blocks starting %llu\n", num, start);
-		ext4_free_blocks(handle, inode, 0, start, num, flags);
+		ext4_free_blocks(handle, inode, NULL, start, num, flags);
 
 	} else {
 		printk(KERN_INFO "strange request: removal(2) "
@@ -2262,19 +2294,19 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
  */
 static int
 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
-		struct ext4_ext_path *path, ext4_lblk_t start,
-		ext4_lblk_t end)
+		 struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
+		 ext4_lblk_t start, ext4_lblk_t end)
 {
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	int err = 0, correct_index = 0;
 	int depth = ext_depth(inode), credits;
 	struct ext4_extent_header *eh;
-	ext4_lblk_t a, b, block;
+	ext4_lblk_t a, b;
 	unsigned num;
 	ext4_lblk_t ex_ee_block;
 	unsigned short ex_ee_len;
 	unsigned uninitialized = 0;
 	struct ext4_extent *ex;
-	struct ext4_map_blocks map;
 
 	/* the header must be checked already in ext4_ext_remove_space() */
 	ext_debug("truncate since %u in leaf\n", start);
@@ -2291,6 +2323,8 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 	ex_ee_block = le32_to_cpu(ex->ee_block);
 	ex_ee_len = ext4_ext_get_actual_len(ex);
 
+	trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
+
 	while (ex >= EXT_FIRST_EXTENT(eh) &&
 			ex_ee_block + ex_ee_len > start) {
 
@@ -2315,86 +2349,18 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 			ex_ee_block = le32_to_cpu(ex->ee_block);
 			ex_ee_len = ext4_ext_get_actual_len(ex);
 			continue;
-		} else if (a != ex_ee_block &&
-			b != ex_ee_block + ex_ee_len - 1) {
-			/*
-			 * If this is a truncate, then this condition should
-			 * never happen because at least one of the end points
-			 * needs to be on the edge of the extent.
-			 */
-			if (end == EXT_MAX_BLOCKS - 1) {
-				ext_debug("  bad truncate %u:%u\n",
-						start, end);
-				block = 0;
-				num = 0;
-				err = -EIO;
-				goto out;
-			}
-			/*
-			 * else this is a hole punch, so the extent needs to
-			 * be split since neither edge of the hole is on the
-			 * extent edge
-			 */
-			else{
-				map.m_pblk = ext4_ext_pblock(ex);
-				map.m_lblk = ex_ee_block;
-				map.m_len = b - ex_ee_block;
-
-				err = ext4_split_extent(handle,
-					inode, path, &map, 0,
-					EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
-					EXT4_GET_BLOCKS_PRE_IO);
-
-				if (err < 0)
-					goto out;
-
-				ex_ee_len = ext4_ext_get_actual_len(ex);
-
-				b = ex_ee_block+ex_ee_len - 1 < end ?
-					ex_ee_block+ex_ee_len - 1 : end;
-
-				/* Then remove tail of this extent */
-				block = ex_ee_block;
-				num = a - block;
-			}
+		} else if (b != ex_ee_block + ex_ee_len - 1) {
+			EXT4_ERROR_INODE(inode,"  bad truncate %u:%u\n",
+					 start, end);
+			err = -EIO;
+			goto out;
 		} else if (a != ex_ee_block) {
 			/* remove tail of the extent */
-			block = ex_ee_block;
-			num = a - block;
-		} else if (b != ex_ee_block + ex_ee_len - 1) {
-			/* remove head of the extent */
-			block = b;
-			num =  ex_ee_block + ex_ee_len - b;
-
-			/*
-			 * If this is a truncate, this condition
-			 * should never happen
-			 */
-			if (end == EXT_MAX_BLOCKS - 1) {
-				ext_debug("  bad truncate %u:%u\n",
-					start, end);
-				err = -EIO;
-				goto out;
-			}
+			num = a - ex_ee_block;
 		} else {
 			/* remove whole extent: excellent! */
-			block = ex_ee_block;
 			num = 0;
-			if (a != ex_ee_block) {
-				ext_debug("  bad truncate %u:%u\n",
-					start, end);
-				err = -EIO;
-				goto out;
-			}
-
-			if (b != ex_ee_block + ex_ee_len - 1) {
-				ext_debug("  bad truncate %u:%u\n",
-					start, end);
-				err = -EIO;
-				goto out;
-			}
 		}
-
 		/*
 		 * 3 for leaf, sb, and inode plus 2 (bmap and group
 		 * descriptor) for each block group; assume two block
@@ -2416,23 +2382,15 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 		if (err)
 			goto out;
 
-		err = ext4_remove_blocks(handle, inode, ex, a, b);
+		err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
+					 a, b);
 		if (err)
 			goto out;
 
-		if (num == 0) {
+		if (num == 0)
 			/* this extent is removed; mark slot entirely unused */
 			ext4_ext_store_pblock(ex, 0);
-		} else if (block != ex_ee_block) {
-			/*
-			 * If this was a head removal, then we need to update
-			 * the physical block since it is now at a different
-			 * location
-			 */
-			ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a));
-		}
 
-		ex->ee_block = cpu_to_le32(block);
 		ex->ee_len = cpu_to_le16(num);
 		/*
 		 * Do not mark uninitialized if all the blocks in the
@@ -2440,11 +2398,6 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 		 */
 		if (uninitialized && num)
 			ext4_ext_mark_uninitialized(ex);
-
-		err = ext4_ext_dirty(handle, inode, path + depth);
-		if (err)
-			goto out;
-
 		/*
 		 * If the extent was completely released,
 		 * we need to remove it from the leaf
@@ -2464,9 +2417,14 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 					sizeof(struct ext4_extent));
 			}
 			le16_add_cpu(&eh->eh_entries, -1);
-		}
+		} else
+			*partial_cluster = 0;
 
-		ext_debug("new extent: %u:%u:%llu\n", block, num,
+		err = ext4_ext_dirty(handle, inode, path + depth);
+		if (err)
+			goto out;
+
+		ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
 				ext4_ext_pblock(ex));
 		ex--;
 		ex_ee_block = le32_to_cpu(ex->ee_block);
@@ -2476,6 +2434,25 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
 	if (correct_index && eh->eh_entries)
 		err = ext4_ext_correct_indexes(handle, inode, path);
 
+	/*
+	 * If there is still a entry in the leaf node, check to see if
+	 * it references the partial cluster.  This is the only place
+	 * where it could; if it doesn't, we can free the cluster.
+	 */
+	if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
+	    (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
+	     *partial_cluster)) {
+		int flags = EXT4_FREE_BLOCKS_FORGET;
+
+		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+			flags |= EXT4_FREE_BLOCKS_METADATA;
+
+		ext4_free_blocks(handle, inode, NULL,
+				 EXT4_C2B(sbi, *partial_cluster),
+				 sbi->s_cluster_ratio, flags);
+		*partial_cluster = 0;
+	}
+
 	/* if this leaf is free, then we should
 	 * remove it from index block above */
 	if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
@@ -2511,6 +2488,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
 	struct super_block *sb = inode->i_sb;
 	int depth = ext_depth(inode);
 	struct ext4_ext_path *path;
+	ext4_fsblk_t partial_cluster = 0;
 	handle_t *handle;
 	int i, err;
 
@@ -2524,6 +2502,8 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
 again:
 	ext4_ext_invalidate_cache(inode);
 
+	trace_ext4_ext_remove_space(inode, start, depth);
+
 	/*
 	 * We start scanning from right side, freeing all the blocks
 	 * after i_size and walking into the tree depth-wise.
@@ -2546,7 +2526,8 @@ again:
 		if (i == depth) {
 			/* this is leaf block */
 			err = ext4_ext_rm_leaf(handle, inode, path,
-					start, EXT_MAX_BLOCKS - 1);
+					       &partial_cluster, start,
+					       EXT_MAX_BLOCKS - 1);
 			/* root level has p_bh == NULL, brelse() eats this */
 			brelse(path[i].p_bh);
 			path[i].p_bh = NULL;
@@ -2618,6 +2599,24 @@ again:
 		}
 	}
 
+	trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
+			path->p_hdr->eh_entries);
+
+	/* If we still have something in the partial cluster and we have removed
+	 * even the first extent, then we should free the blocks in the partial
+	 * cluster as well. */
+	if (partial_cluster && path->p_hdr->eh_entries == 0) {
+		int flags = EXT4_FREE_BLOCKS_FORGET;
+
+		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+			flags |= EXT4_FREE_BLOCKS_METADATA;
+
+		ext4_free_blocks(handle, inode, NULL,
+				 EXT4_C2B(EXT4_SB(sb), partial_cluster),
+				 EXT4_SB(sb)->s_cluster_ratio, flags);
+		partial_cluster = 0;
+	}
+
 	/* TODO: flexible tree reduction should be here */
 	if (path->p_hdr->eh_entries == 0) {
 		/*
@@ -2909,17 +2908,29 @@ out:
  *   a> There is no split required: Entire extent should be initialized
  *   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
+ *
+ * Pre-conditions:
+ *  - The extent pointed to by 'path' is uninitialized.
+ *  - The extent pointed to by 'path' contains a superset
+ *    of the logical span [map->m_lblk, map->m_lblk + map->m_len).
+ *
+ * Post-conditions on success:
+ *  - the returned value is the number of blocks beyond map->l_lblk
+ *    that are allocated and initialized.
+ *    It is guaranteed to be >= map->m_len.
  */
 static int ext4_ext_convert_to_initialized(handle_t *handle,
 					   struct inode *inode,
 					   struct ext4_map_blocks *map,
 					   struct ext4_ext_path *path)
 {
+	struct ext4_extent_header *eh;
 	struct ext4_map_blocks split_map;
 	struct ext4_extent zero_ex;
 	struct ext4_extent *ex;
 	ext4_lblk_t ee_block, eof_block;
-	unsigned int allocated, ee_len, depth;
+	unsigned int ee_len, depth;
+	int allocated;
 	int err = 0;
 	int split_flag = 0;
 
@@ -2933,11 +2944,93 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 		eof_block = map->m_lblk + map->m_len;
 
 	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 - (map->m_lblk - ee_block);
 
+	trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
+
+	/* Pre-conditions */
+	BUG_ON(!ext4_ext_is_uninitialized(ex));
+	BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
+	BUG_ON(map->m_lblk + map->m_len > ee_block + ee_len);
+
+	/*
+	 * Attempt to transfer newly initialized blocks from the currently
+	 * uninitialized extent to its left neighbor. This is much cheaper
+	 * than an insertion followed by a merge as those involve costly
+	 * memmove() calls. This is the common case in steady state for
+	 * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append
+	 * writes.
+	 *
+	 * Limitations of the current logic:
+	 *  - L1: we only deal with writes at the start of the extent.
+	 *    The approach could be extended to writes at the end
+	 *    of the extent but this scenario was deemed less common.
+	 *  - L2: we do not deal with writes covering the whole extent.
+	 *    This would require removing the extent if the transfer
+	 *    is possible.
+	 *  - L3: we only attempt to merge with an extent stored in the
+	 *    same extent tree node.
+	 */
+	if ((map->m_lblk == ee_block) &&	/*L1*/
+		(map->m_len < ee_len) &&	/*L2*/
+		(ex > EXT_FIRST_EXTENT(eh))) {	/*L3*/
+		struct ext4_extent *prev_ex;
+		ext4_lblk_t prev_lblk;
+		ext4_fsblk_t prev_pblk, ee_pblk;
+		unsigned int prev_len, write_len;
+
+		prev_ex = ex - 1;
+		prev_lblk = le32_to_cpu(prev_ex->ee_block);
+		prev_len = ext4_ext_get_actual_len(prev_ex);
+		prev_pblk = ext4_ext_pblock(prev_ex);
+		ee_pblk = ext4_ext_pblock(ex);
+		write_len = map->m_len;
+
+		/*
+		 * A transfer of blocks from 'ex' to 'prev_ex' is allowed
+		 * upon those conditions:
+		 * - C1: prev_ex is initialized,
+		 * - C2: prev_ex is logically abutting ex,
+		 * - C3: prev_ex is physically abutting ex,
+		 * - C4: prev_ex can receive the additional blocks without
+		 *   overflowing the (initialized) length limit.
+		 */
+		if ((!ext4_ext_is_uninitialized(prev_ex)) &&		/*C1*/
+			((prev_lblk + prev_len) == ee_block) &&		/*C2*/
+			((prev_pblk + prev_len) == ee_pblk) &&		/*C3*/
+			(prev_len < (EXT_INIT_MAX_LEN - write_len))) {	/*C4*/
+			err = ext4_ext_get_access(handle, inode, path + depth);
+			if (err)
+				goto out;
+
+			trace_ext4_ext_convert_to_initialized_fastpath(inode,
+				map, ex, prev_ex);
+
+			/* Shift the start of ex by 'write_len' blocks */
+			ex->ee_block = cpu_to_le32(ee_block + write_len);
+			ext4_ext_store_pblock(ex, ee_pblk + write_len);
+			ex->ee_len = cpu_to_le16(ee_len - write_len);
+			ext4_ext_mark_uninitialized(ex); /* Restore the flag */
+
+			/* Extend prev_ex by 'write_len' blocks */
+			prev_ex->ee_len = cpu_to_le16(prev_len + write_len);
+
+			/* Mark the block containing both extents as dirty */
+			ext4_ext_dirty(handle, inode, path + depth);
+
+			/* Update path to point to the right extent */
+			path[depth].p_ext = prev_ex;
+
+			/* Result: number of initialized blocks past m_lblk */
+			allocated = write_len;
+			goto out;
+		}
+	}
+
 	WARN_ON(map->m_lblk < ee_block);
 	/*
 	 * It is safe to convert extent to initialized via explicit
@@ -3165,6 +3258,192 @@ static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
 	return ext4_mark_inode_dirty(handle, inode);
 }
 
+/**
+ * ext4_find_delalloc_range: find delayed allocated block in the given range.
+ *
+ * Goes through the buffer heads in the range [lblk_start, lblk_end] and returns
+ * whether there are any buffers marked for delayed allocation. It returns '1'
+ * on the first delalloc'ed buffer head found. If no buffer head in the given
+ * range is marked for delalloc, it returns 0.
+ * lblk_start should always be <= lblk_end.
+ * search_hint_reverse is to indicate that searching in reverse from lblk_end to
+ * lblk_start might be more efficient (i.e., we will likely hit the delalloc'ed
+ * block sooner). This is useful when blocks are truncated sequentially from
+ * lblk_start towards lblk_end.
+ */
+static int ext4_find_delalloc_range(struct inode *inode,
+				    ext4_lblk_t lblk_start,
+				    ext4_lblk_t lblk_end,
+				    int search_hint_reverse)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct buffer_head *head, *bh = NULL;
+	struct page *page;
+	ext4_lblk_t i, pg_lblk;
+	pgoff_t index;
+
+	/* reverse search wont work if fs block size is less than page size */
+	if (inode->i_blkbits < PAGE_CACHE_SHIFT)
+		search_hint_reverse = 0;
+
+	if (search_hint_reverse)
+		i = lblk_end;
+	else
+		i = lblk_start;
+
+	index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+	while ((i >= lblk_start) && (i <= lblk_end)) {
+		page = find_get_page(mapping, index);
+		if (!page)
+			goto nextpage;
+
+		if (!page_has_buffers(page))
+			goto nextpage;
+
+		head = page_buffers(page);
+		if (!head)
+			goto nextpage;
+
+		bh = head;
+		pg_lblk = index << (PAGE_CACHE_SHIFT -
+						inode->i_blkbits);
+		do {
+			if (unlikely(pg_lblk < lblk_start)) {
+				/*
+				 * This is possible when fs block size is less
+				 * than page size and our cluster starts/ends in
+				 * middle of the page. So we need to skip the
+				 * initial few blocks till we reach the 'lblk'
+				 */
+				pg_lblk++;
+				continue;
+			}
+
+			/* Check if the buffer is delayed allocated and that it
+			 * is not yet mapped. (when da-buffers are mapped during
+			 * their writeout, their da_mapped bit is set.)
+			 */
+			if (buffer_delay(bh) && !buffer_da_mapped(bh)) {
+				page_cache_release(page);
+				trace_ext4_find_delalloc_range(inode,
+						lblk_start, lblk_end,
+						search_hint_reverse,
+						1, i);
+				return 1;
+			}
+			if (search_hint_reverse)
+				i--;
+			else
+				i++;
+		} while ((i >= lblk_start) && (i <= lblk_end) &&
+				((bh = bh->b_this_page) != head));
+nextpage:
+		if (page)
+			page_cache_release(page);
+		/*
+		 * Move to next page. 'i' will be the first lblk in the next
+		 * page.
+		 */
+		if (search_hint_reverse)
+			index--;
+		else
+