Merge commit 'origin/master' into next

Manual merge of:
	arch/powerpc/kernel/asm-offsets.c

1 files changed, 365 insertions, 228 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2a9ffd528dd1..875db944b22f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -372,20 +372,21 @@ static int ext4_block_to_path(struct inode *inode,
 }
 
 static int __ext4_check_blockref(const char *function, struct inode *inode,
-				 __le32 *p, unsigned int max) {
-
-	unsigned int maxblocks = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es);
+				 __le32 *p, unsigned int max)
+{
 	__le32 *bref = p;
+	unsigned int blk;
+
 	while (bref < p+max) {
-		if (unlikely(le32_to_cpu(*bref) >= maxblocks)) {
+		blk = le32_to_cpu(*bref++);
+		if (blk && 
+		    unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb), 
+						    blk, 1))) {
 			ext4_error(inode->i_sb, function,
-				   "block reference %u >= max (%u) "
-				   "in inode #%lu, offset=%d",
-				   le32_to_cpu(*bref), maxblocks,
-				   inode->i_ino, (int)(bref-p));
+				   "invalid block reference %u "
+				   "in inode #%lu", blk, inode->i_ino);
  			return -EIO;
  		}
-		bref++;
  	}
  	return 0;
 }
@@ -892,6 +893,10 @@ err_out:
 }
 
 /*
+ * The ext4_ind_get_blocks() function handles non-extents inodes
+ * (i.e., using the traditional indirect/double-indirect i_blocks
+ * scheme) for ext4_get_blocks().
+ *
  * Allocation strategy is simple: if we have to allocate something, we will
  * have to go the whole way to leaf. So let's do it before attaching anything
  * to tree, set linkage between the newborn blocks, write them if sync is
@@ -909,15 +914,16 @@ err_out:
  * return = 0, if plain lookup failed.
  * return < 0, error case.
  *
- *
- * Need to be called with
- * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
- * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ * The ext4_ind_get_blocks() function should be called with
+ * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
+ * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
+ * blocks.
  */
-static int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
+static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
 				  ext4_lblk_t iblock, unsigned int maxblocks,
 				  struct buffer_head *bh_result,
-				  int create, int extend_disksize)
+				  int flags)
 {
 	int err = -EIO;
 	ext4_lblk_t offsets[4];
@@ -927,14 +933,11 @@ static int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 	int indirect_blks;
 	int blocks_to_boundary = 0;
 	int depth;
-	struct ext4_inode_info *ei = EXT4_I(inode);
 	int count = 0;
 	ext4_fsblk_t first_block = 0;
-	loff_t disksize;
-
 
 	J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
-	J_ASSERT(handle != NULL || create == 0);
+	J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
 	depth = ext4_block_to_path(inode, iblock, offsets,
 					&blocks_to_boundary);
 
@@ -963,7 +966,7 @@ static int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 	}
 
 	/* Next simple case - plain lookup or failed read of indirect block */
-	if (!create || err == -EIO)
+	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
 		goto cleanup;
 
 	/*
@@ -997,19 +1000,7 @@ static int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 	if (!err)
 		err = ext4_splice_branch(handle, inode, iblock,
 					partial, indirect_blks, count);
-	/*
-	 * i_disksize growing is protected by i_data_sem.  Don't forget to
-	 * protect it if you're about to implement concurrent
-	 * ext4_get_block() -bzzz
-	*/
-	if (!err && extend_disksize) {
-		disksize = ((loff_t) iblock + count) << inode->i_blkbits;
-		if (disksize > i_size_read(inode))
-			disksize = i_size_read(inode);
-		if (disksize > ei->i_disksize)
-			ei->i_disksize = disksize;
-	}
-	if (err)
+	else 
 		goto cleanup;
 
 	set_buffer_new(bh_result);
@@ -1120,8 +1111,23 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
 		ext4_discard_preallocations(inode);
 }
 
+static int check_block_validity(struct inode *inode, sector_t logical,
+				sector_t phys, int len)
+{
+	if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), phys, len)) {
+		ext4_error(inode->i_sb, "check_block_validity",
+			   "inode #%lu logical block %llu mapped to %llu "
+			   "(size %d)", inode->i_ino,
+			   (unsigned long long) logical,
+			   (unsigned long long) phys, len);
+		WARN_ON(1);
+		return -EIO;
+	}
+	return 0;
+}
+
 /*
- * The ext4_get_blocks_wrap() function try to look up the requested blocks,
+ * The ext4_get_blocks() function tries to look up the requested blocks,
  * and returns if the blocks are already mapped.
  *
  * Otherwise it takes the write lock of the i_data_sem and allocate blocks
@@ -1129,7 +1135,7 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
  * mapped.
  *
  * If file type is extents based, it will call ext4_ext_get_blocks(),
- * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping
+ * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
  * based files
  *
  * On success, it returns the number of blocks being mapped or allocate.
@@ -1142,9 +1148,9 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
  *
  * It returns the error in case of allocation failure.
  */
-int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
-			unsigned int max_blocks, struct buffer_head *bh,
-			int create, int extend_disksize, int flag)
+int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
+		    unsigned int max_blocks, struct buffer_head *bh,
+		    int flags)
 {
 	int retval;
 
@@ -1152,21 +1158,28 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 	clear_buffer_unwritten(bh);
 
 	/*
-	 * Try to see if we can get  the block without requesting
-	 * for new file system block.
+	 * Try to see if we can get the block without requesting a new
+	 * file system block.
 	 */
 	down_read((&EXT4_I(inode)->i_data_sem));
 	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
 		retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,
-				bh, 0, 0);
+				bh, 0);
 	} else {
-		retval = ext4_get_blocks_handle(handle,
-				inode, block, max_blocks, bh, 0, 0);
+		retval = ext4_ind_get_blocks(handle, inode, block, max_blocks,
+					     bh, 0);
 	}
 	up_read((&EXT4_I(inode)->i_data_sem));
 
+	if (retval > 0 && buffer_mapped(bh)) {
+		int ret = check_block_validity(inode, block, 
+					       bh->b_blocknr, retval);
+		if (ret != 0)
+			return ret;
+	}
+
 	/* If it is only a block(s) look up */
-	if (!create)
+	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
 		return retval;
 
 	/*
@@ -1205,7 +1218,7 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 	 * let the underlying get_block() function know to
 	 * avoid double accounting
 	 */
-	if (flag)
+	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
 		EXT4_I(inode)->i_delalloc_reserved_flag = 1;
 	/*
 	 * We need to check for EXT4 here because migrate
@@ -1213,10 +1226,10 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 	 */
 	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
 		retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,
-				bh, create, extend_disksize);
+					      bh, flags);
 	} else {
-		retval = ext4_get_blocks_handle(handle, inode, block,
-				max_blocks, bh, create, extend_disksize);
+		retval = ext4_ind_get_blocks(handle, inode, block,
+					     max_blocks, bh, flags);
 
 		if (retval > 0 && buffer_new(bh)) {
 			/*
@@ -1229,18 +1242,23 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 		}
 	}
 
-	if (flag) {
+	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
 		EXT4_I(inode)->i_delalloc_reserved_flag = 0;
-		/*
-		 * Update reserved blocks/metadata blocks
-		 * after successful block allocation
-		 * which were deferred till now
-		 */
-		if ((retval > 0) && buffer_delay(bh))
-			ext4_da_update_reserve_space(inode, retval);
-	}
+
+	/*
+	 * Update reserved blocks/metadata blocks after successful
+	 * block allocation which had been deferred till now.
+	 */
+	if ((retval > 0) && (flags & EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE))
+		ext4_da_update_reserve_space(inode, retval);
 
 	up_write((&EXT4_I(inode)->i_data_sem));
+	if (retval > 0 && buffer_mapped(bh)) {
+		int ret = check_block_validity(inode, block, 
+					       bh->b_blocknr, retval);
+		if (ret != 0)
+			return ret;
+	}
 	return retval;
 }
 
@@ -1268,8 +1286,8 @@ int ext4_get_block(struct inode *inode, sector_t iblock,
 		started = 1;
 	}
 
-	ret = ext4_get_blocks_wrap(handle, inode, iblock,
-					max_blocks, bh_result, create, 0, 0);
+	ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,
+			      create ? EXT4_GET_BLOCKS_CREATE : 0);
 	if (ret > 0) {
 		bh_result->b_size = (ret << inode->i_blkbits);
 		ret = 0;
@@ -1288,17 +1306,19 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
 {
 	struct buffer_head dummy;
 	int fatal = 0, err;
+	int flags = 0;
 
 	J_ASSERT(handle != NULL || create == 0);
 
 	dummy.b_state = 0;
 	dummy.b_blocknr = -1000;
 	buffer_trace_init(&dummy.b_history);
-	err = ext4_get_blocks_wrap(handle, inode, block, 1,
-					&dummy, create, 1, 0);
+	if (create)
+		flags |= EXT4_GET_BLOCKS_CREATE;
+	err = ext4_get_blocks(handle, inode, block, 1, &dummy, flags);
 	/*
-	 * ext4_get_blocks_handle() returns number of blocks
-	 * mapped. 0 in case of a HOLE.
+	 * ext4_get_blocks() returns number of blocks mapped. 0 in
+	 * case of a HOLE.
 	 */
 	if (err > 0) {
 		if (err > 1)
@@ -1439,7 +1459,7 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
 				struct page **pagep, void **fsdata)
 {
 	struct inode *inode = mapping->host;
-	int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
+	int ret, needed_blocks;
 	handle_t *handle;
 	int retries = 0;
 	struct page *page;
@@ -1450,6 +1470,11 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
 		   "dev %s ino %lu pos %llu len %u flags %u",
 		   inode->i_sb->s_id, inode->i_ino,
 		   (unsigned long long) pos, len, flags);
+	/*
+	 * Reserve one block more for addition to orphan list in case
+	 * we allocate blocks but write fails for some reason
+	 */
+	needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
  	index = pos >> PAGE_CACHE_SHIFT;
 	from = pos & (PAGE_CACHE_SIZE - 1);
 	to = from + len;
@@ -1483,15 +1508,30 @@ retry:
 
 	if (ret) {
 		unlock_page(page);
-		ext4_journal_stop(handle);
 		page_cache_release(page);
 		/*
 		 * block_write_begin may have instantiated a few blocks
 		 * outside i_size.  Trim these off again. Don't need
 		 * i_size_read because we hold i_mutex.
+		 *
+		 * Add inode to orphan list in case we crash before
+		 * truncate finishes
 		 */
 		if (pos + len > inode->i_size)
+			ext4_orphan_add(handle, inode);
+
+		ext4_journal_stop(handle);
+		if (pos + len > inode->i_size) {
 			vmtruncate(inode, inode->i_size);
+			/* 
+			 * If vmtruncate failed early the inode might
+			 * still be on the orphan list; we need to
+			 * make sure the inode is removed from the
+			 * orphan list in that case.
+			 */
+			if (inode->i_nlink)
+				ext4_orphan_del(NULL, inode);
+		}
 	}
 
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
@@ -1509,6 +1549,52 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh)
 	return ext4_handle_dirty_metadata(handle, NULL, bh);
 }
 
+static int ext4_generic_write_end(struct file *file,
+				struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *page, void *fsdata)
+{
+	int i_size_changed = 0;
+	struct inode *inode = mapping->host;
+	handle_t *handle = ext4_journal_current_handle();
+
+	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
+
+	/*
+	 * No need to use i_size_read() here, the i_size
+	 * cannot change under us because we hold i_mutex.
+	 *
+	 * But it's important to update i_size while still holding page lock:
+	 * page writeout could otherwise come in and zero beyond i_size.
+	 */
+	if (pos + copied > inode->i_size) {
+		i_size_write(inode, pos + copied);
+		i_size_changed = 1;
+	}
+
+	if (pos + copied >  EXT4_I(inode)->i_disksize) {
+		/* We need to mark inode dirty even if
+		 * new_i_size is less that inode->i_size
+		 * bu greater than i_disksize.(hint delalloc)
+		 */
+		ext4_update_i_disksize(inode, (pos + copied));
+		i_size_changed = 1;
+	}
+	unlock_page(page);
+	page_cache_release(page);
+
+	/*
+	 * Don't mark the inode dirty under page lock. First, it unnecessarily
+	 * makes the holding time of page lock longer. Second, it forces lock
+	 * ordering of page lock and transaction start for journaling
+	 * filesystems.
+	 */
+	if (i_size_changed)
+		ext4_mark_inode_dirty(handle, inode);
+
+	return copied;
+}
+
 /*
  * We need to pick up the new inode size which generic_commit_write gave us
  * `file' can be NULL - eg, when called from page_symlink().
@@ -1532,21 +1618,15 @@ static int ext4_ordered_write_end(struct file *file,
 	ret = ext4_jbd2_file_inode(handle, inode);
 
 	if (ret == 0) {
-		loff_t new_i_size;
-
-		new_i_size = pos + copied;
-		if (new_i_size > EXT4_I(inode)->i_disksize) {
-			ext4_update_i_disksize(inode, new_i_size);
-			/* We need to mark inode dirty even if
-			 * new_i_size is less that inode->i_size
-			 * bu greater than i_disksize.(hint delalloc)
-			 */
-			ext4_mark_inode_dirty(handle, inode);
-		}
-
-		ret2 = generic_write_end(file, mapping, pos, len, copied,
+		ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
 							page, fsdata);
 		copied = ret2;
+		if (pos + len > inode->i_size)
+			/* if we have allocated more blocks and copied
+			 * less. We will have blocks allocated outside
+			 * inode->i_size. So truncate them
+			 */
+			ext4_orphan_add(handle, inode);
 		if (ret2 < 0)
 			ret = ret2;
 	}
@@ -1554,6 +1634,18 @@ static int ext4_ordered_write_end(struct file *file,
 	if (!ret)
 		ret = ret2;
 
+	if (pos + len > inode->i_size) {
+		vmtruncate(inode, inode->i_size);
+		/* 
+		 * If vmtruncate failed early the inode might still be
+		 * on the orphan list; we need to make sure the inode
+		 * is removed from the orphan list in that case.
+		 */
+		if (inode->i_nlink)
+			ext4_orphan_del(NULL, inode);
+	}
+
+
 	return ret ? ret : copied;
 }
 
@@ -1565,25 +1657,21 @@ static int ext4_writeback_write_end(struct file *file,
 	handle_t *handle = ext4_journal_current_handle();
 	struct inode *inode = mapping->host;
 	int ret = 0, ret2;
-	loff_t new_i_size;
 
 	trace_mark(ext4_writeback_write_end,
 		   "dev %s ino %lu pos %llu len %u copied %u",
 		   inode->i_sb->s_id, inode->i_ino,
 		   (unsigned long long) pos, len, copied);
-	new_i_size = pos + copied;
-	if (new_i_size > EXT4_I(inode)->i_disksize) {
-		ext4_update_i_disksize(inode, new_i_size);
-		/* We need to mark inode dirty even if
-		 * new_i_size is less that inode->i_size
-		 * bu greater than i_disksize.(hint delalloc)
-		 */
-		ext4_mark_inode_dirty(handle, inode);
-	}
-
-	ret2 = generic_write_end(file, mapping, pos, len, copied,
+	ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
 							page, fsdata);
 	copied = ret2;
+	if (pos + len > inode->i_size)
+		/* if we have allocated more blocks and copied
+		 * less. We will have blocks allocated outside
+		 * inode->i_size. So truncate them
+		 */
+		ext4_orphan_add(handle, inode);
+
 	if (ret2 < 0)
 		ret = ret2;
 
@@ -1591,6 +1679,17 @@ static int ext4_writeback_write_end(struct file *file,
 	if (!ret)
 		ret = ret2;
 
+	if (pos + len > inode->i_size) {
+		vmtruncate(inode, inode->i_size);
+		/* 
+		 * If vmtruncate failed early the inode might still be
+		 * on the orphan list; we need to make sure the inode
+		 * is removed from the orphan list in that case.
+		 */
+		if (inode->i_nlink)
+			ext4_orphan_del(NULL, inode);
+	}
+
 	return ret ? ret : copied;
 }
 
@@ -1635,10 +1734,27 @@ static int ext4_journalled_write_end(struct file *file,
 	}
 
 	unlock_page(page);
+	page_cache_release(page);
+	if (pos + len > inode->i_size)
+		/* if we have allocated more blocks and copied
+		 * less. We will have blocks allocated outside
+		 * inode->i_size. So truncate them
+		 */
+		ext4_orphan_add(handle, inode);
+
 	ret2 = ext4_journal_stop(handle);
 	if (!ret)
 		ret = ret2;
-	page_cache_release(page);
+	if (pos + len > inode->i_size) {
+		vmtruncate(inode, inode->i_size);
+		/* 
+		 * If vmtruncate failed early the inode might still be
+		 * on the orphan list; we need to make sure the inode
+		 * is removed from the orphan list in that case.
+		 */
+		if (inode->i_nlink)
+			ext4_orphan_del(NULL, inode);
+	}
 
 	return ret ? ret : copied;
 }
@@ -1852,7 +1968,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
  * @logical - first logical block to start assignment with
  *
  * the function goes through all passed space and put actual disk
- * block numbers into buffer heads, dropping BH_Delay
+ * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
  */
 static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
 				 struct buffer_head *exbh)
@@ -1902,16 +2018,24 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
 			do {
 				if (cur_logical >= logical + blocks)
 					break;
-				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;
+
+				if (buffer_delay(bh) ||
+						buffer_unwritten(bh)) {
+
+					BUG_ON(bh->b_bdev != inode->i_sb->s_bdev);
+
+					if (buffer_delay(bh)) {
+						clear_buffer_delay(bh);
+						bh->b_blocknr = pblock;
+					} else {
+						/*
+						 * unwritten already should have
+						 * blocknr assigned. Verify that
+						 */
+						clear_buffer_unwritten(bh);
+						BUG_ON(bh->b_blocknr != pblock);
+					}
+
 				} else if (buffer_mapped(bh))
 					BUG_ON(bh->b_blocknr != pblock);
 
@@ -1990,51 +2114,6 @@ static void ext4_print_free_blocks(struct inode *inode)
 	return;
 }
 
-#define		EXT4_DELALLOC_RSVED	1
-static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
-				   struct buffer_head *bh_result, int create)
-{
-	int ret;
-	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
-	loff_t disksize = EXT4_I(inode)->i_disksize;
-	handle_t *handle = NULL;
-
-	handle = ext4_journal_current_handle();
-	BUG_ON(!handle);
-	ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
-				   bh_result, create, 0, EXT4_DELALLOC_RSVED);
-	if (ret <= 0)
-		return ret;
-
-	bh_result->b_size = (ret << inode->i_blkbits);
-
-	if (ext4_should_order_data(inode)) {
-		int retval;
-		retval = ext4_jbd2_file_inode(handle, inode);
-		if (retval)
-			/*
-			 * Failed to add inode for ordered mode. Don't
-			 * update file size
-			 */
-			return retval;
-	}
-
-	/*
-	 * Update on-disk size along with block allocation we don't
-	 * use 'extend_disksize' as size may change within already
-	 * allocated block -bzzz
-	 */
-	disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
-	if (disksize > i_size_read(inode))
-		disksize = i_size_read(inode);
-	if (disksize > EXT4_I(inode)->i_disksize) {
-		ext4_update_i_disksize(inode, disksize);
-		ret = ext4_mark_inode_dirty(handle, inode);
-		return ret;
-	}
-	return 0;
-}
-
 /*
  * mpage_da_map_blocks - go through given space
  *
@@ -2045,29 +2124,57 @@ static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
  */
 static int mpage_da_map_blocks(struct mpage_da_data *mpd)
 {
-	int err = 0;
+	int err, blks, get_blocks_flags;
 	struct buffer_head new;
-	sector_t next;
+	sector_t next = mpd->b_blocknr;
+	unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
+	loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
+	handle_t *handle = NULL;
 
 	/*
 	 * We consider only non-mapped and non-allocated blocks
 	 */
 	if ((mpd->b_state  & (1 << BH_Mapped)) &&
-	    !(mpd->b_state & (1 << BH_Delay)))
+		!(mpd->b_state & (1 << BH_Delay)) &&
+		!(mpd->b_state & (1 << BH_Unwritten)))
 		return 0;
-	new.b_state = mpd->b_state;
-	new.b_blocknr = 0;
-	new.b_size = mpd->b_size;
-	next = mpd->b_blocknr;
+
 	/*
-	 * If we didn't accumulate anything
-	 * to write simply return
+	 * If we didn't accumulate anything to write simply return
 	 */
-	if (!new.b_size)
+	if (!mpd->b_size)
 		return 0;
 
-	err = ext4_da_get_block_write(mpd->inode, next, &new, 1);
-	if (err) {
+	handle = ext4_journal_current_handle();
+	BUG_ON(!handle);
+
+	/*
+	 * Call ext4_get_blocks() to allocate any delayed allocation
+	 * blocks, or to convert an uninitialized extent to be
+	 * initialized (in the case where we have written into
+	 * one or more preallocated blocks).
+	 *
+	 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
+	 * indicate that we are on the delayed allocation path.  This
+	 * affects functions in many different parts of the allocation
+	 * call path.  This flag exists primarily because we don't
+	 * want to change *many* call functions, so ext4_get_blocks()
+	 * will set the magic i_delalloc_reserved_flag once the
+	 * inode's allocation semaphore is taken.
+	 *
+	 * If the blocks in questions were delalloc blocks, set
+	 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
+	 * variables are updated after the blocks have been allocated.
+	 */
+	new.b_state = 0;
+	get_blocks_flags = (EXT4_GET_BLOCKS_CREATE |
+			    EXT4_GET_BLOCKS_DELALLOC_RESERVE);
+	if (mpd->b_state & (1 << BH_Delay))
+		get_blocks_flags |= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE;
+	blks = ext4_get_blocks(handle, mpd->inode, next, max_blocks,
+			       &new, get_blocks_flags);
+	if (blks < 0) {
+		err = blks;
 		/*
 		 * If get block returns with error we simply
 		 * return. Later writepage will redirty the page and
@@ -2100,12 +2207,14 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
 		if (err == -ENOSPC) {
 			ext4_print_free_blocks(mpd->inode);
 		}
-		/* invlaidate all the pages */
+		/* invalidate all the pages */
 		ext4_da_block_invalidatepages(mpd, next,
 				mpd->b_size >> mpd->inode->i_blkbits);
 		return err;
 	}
-	BUG_ON(new.b_size == 0);
+	BUG_ON(blks == 0);
+
+	new.b_size = (blks << mpd->inode->i_blkbits);
 
 	if (buffer_new(&new))
 		__unmap_underlying_blocks(mpd->inode, &new);
@@ -2118,6 +2227,23 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
 	    (mpd->b_state & (1 << BH_Unwritten)))
 		mpage_put_bnr_to_bhs(mpd, next, &new);
 
+	if (ext4_should_order_data(mpd->inode)) {
+		err = ext4_jbd2_file_inode(handle, mpd->inode);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * Update on-disk size along with block allocation.
+	 */
+	disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
+	if (disksize > i_size_read(mpd->inode))
+		disksize = i_size_read(mpd->inode);
+	if (disksize > EXT4_I(mpd->inode)->i_disksize) {
+		ext4_update_i_disksize(mpd->inode, disksize);
+		return ext4_mark_inode_dirty(handle, mpd->inode);
+	}
+
 	return 0;
 }
 
@@ -2192,6 +2318,17 @@ flush_it:
 	return;
 }
 
+static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
+{
+	/*
+	 * unmapped buffer is possible for holes.
+	 * delay buffer is possible with delayed allocation.
+	 * We also need to consider unwritten buffer as unmapped.
+	 */
+	return (!buffer_mapped(bh) || buffer_delay(bh) ||
+				buffer_unwritten(bh)) && buffer_dirty(bh);
+}
+
 /*
  * __mpage_da_writepage - finds extent of pages and blocks
  *
@@ -2276,8 +2413,7 @@ static int __mpage_da_writepage(struct page *page,
 			 * Otherwise we won't make progress
 			 * with the page in ext4_da_writepage
 			 */
-			if (buffer_dirty(bh) &&
-			    (!buffer_mapped(bh) || buffer_delay(bh))) {
+			if (ext4_bh_unmapped_or_delay(NULL, bh)) {
 				mpage_add_bh_to_extent(mpd, logical,
 						       bh->b_size,
 						       bh->b_state);
@@ -2303,8 +2439,16 @@ static int __mpage_da_writepage(struct page *page,
 }
 
 /*
- * this is a special callback for ->write_begin() only
- * it's intention is to return mapped block or reserve space
+ * This is a special get_blocks_t callback which is used by
+ * ext4_da_write_begin().  It will either return mapped block or
+ * reserve space for a single block.
+ *
+ * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
+ * We also have b_blocknr = -1 and b_bdev initialized properly
+ *
+ * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
+ * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
+ * initialized properly.
  */
 static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 				  struct buffer_head *bh_result, int create)
@@ -2323,7 +2467,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 	 * preallocated blocks are unmapped but should treated
 	 * the same as allocated blocks.
 	 */
-	ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1,  bh_result, 0, 0, 0);
+	ret = ext4_get_blocks(NULL, inode, iblock, 1,  bh_result, 0);
 	if ((ret == 0) && !buffer_delay(bh_result)) {
 		/* the block isn't (pre)allocated yet, let's reserve space */
 		/*
@@ -2340,40 +2484,53 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 		set_buffer_delay(bh_result);
 	} else if (ret > 0) {
 		bh_result->b_size = (ret << inode->i_blkbits);
-		/*
-		 * With sub-block writes into unwritten extents
-		 * we also need to mark the buffer as new so that
-		 * the unwritten parts of the buffer gets correctly zeroed.
-		 */
-		if (buffer_unwritten(bh_result))
+		if (buffer_unwritten(bh_result)) {
+			/* A delayed write to unwritten bh should
+			 * be marked new and mapped.  Mapped ensures
+			 * that we don't do get_block multiple times
+			 * when we write to the same offset and new
+			 * ensures that we do proper zero out for
+			 * partial write.
+			 */
 			set_buffer_new(bh_result);
+			set_buffer_mapped(bh_result);
+		}
 		ret = 0;
 	}
 
 	return ret;
 }
 
-static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
-{
-	/*
-	 * unmapped buffer is possible for holes.
-	 * delay buffer is possible with delayed allocation
-	 */
-	return ((!buffer_mapped(bh) || buffer_delay(bh)) && buffer_dirty(bh));
-}
-
-static int ext4_normal_get_block_write(struct inode *inode, sector_t iblock,
+/*
+ * This function is used as a standard get_block_t calback function
+ * when there is no desire to allocate any blocks.  It is used as a
+ * callback function for block_prepare_write(), nobh_writepage(), and
+ * block_write_full_page().  These functions should only try to map a
+ * single block at a time.
+ *
+ * Since this function doesn't do block allocations even if the caller
+ * requests it by passing in create=1, it is critically important that
+ * any caller checks to make sure that any buffer heads are returned
+ * by this function are either all already mapped or marked for
+ * delayed allocation before calling nobh_writepage() or
+ * block_write_full_page().  Otherwise, b_blocknr could be left
+ * unitialized, and the page write functions will be taken by
+ * surprise.
+ */
+static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
 				   struct buffer_head *bh_result, int create)
 {
 	int ret = 0;
 	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
 
+	BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
+
 	/*
 	 * we don't want to do block allocation in writepage
 	 * so call get_block_wrap with create = 0
 	 */
-	ret = ext4_get_blocks_wrap(NULL, inode, iblock, max_blocks,
-				   bh_result, 0, 0, 0);
+	ret = ext4_get_blocks(NULL, inode, iblock, max_blocks, bh_result, 0);
+	BUG_ON(create && ret == 0);
 	if (ret > 0) {
 		bh_result->b_size = (ret << inode->i_blkbits);
 		ret = 0;
@@ -2382,10 +2539,11 @@ static int ext4_normal_get_block_write(struct inode *inode, sector_t iblock,
 }
 
 /*
- * get called vi ext4_da_writepages after taking page lock (have journal handle)
- * get called via journal_submit_inode_data_buffers (no journal handle)
- * get called via shrink_page_list via pdflush (no journal handle)
- * or grab_page_cache when doing write_begin (have journal handle)
+ * This function can get called via...
+ *   - ext4_da_writepages after taking page lock (have journal handle)
+ *   - journal_submit_inode_data_buffers (no journal handle)
+ *   - shrink_page_list via pdflush (no journal handle)
+ *   - grab_page_cache when doing write_begin (have journal handle)
  */
 static int ext4_da_writepage(struct page *page,
 				struct writeback_control *wbc)
@@ -2436,7 +2594,7 @@ static int ext4_da_writepage(struct page *page,
 		 * do block allocation here.
 		 */
 		ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
-						ext4_normal_get_block_write);
+					  noalloc_get_block_write);
 		if (!ret) {
 			page_bufs = page_buffers(page);
 			/* check whether all are mapped and non delay */
@@ -2461,11 +2619,10 @@ static int ext4_da_writepage(struct page *page,
 	}
 
 	if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
-		ret = nobh_writepage(page, ext4_normal_get_block_write, wbc);
+		ret = nobh_writepage(page, noalloc_get_block_write, wbc);
 	else
-		ret = block_write_full_page(page,
-						ext4_normal_get_block_write,
-						wbc);
+		ret = block_write_full_page(page, noalloc_get_block_write,
+					    wbc);
 
 	return ret;
 }
@@ -2777,7 +2934,7 @@ retry:
 	*pagep = page;
 
 	ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-							ext4_da_get_block_prep);
+				ext4_da_get_block_prep);
 	if (ret < 0) {
 		unlock_page(page);
 		ext4_journal_stop(handle);
@@ -2815,7 +2972,7 @@ static int ext4_da_should_update_i_disksize(struct page *page,
 	for (i = 0; i < idx; i++)
 		bh = bh->b_this_page;
 
-	if (!buffer_mapped(bh) || (buffer_delay(bh)))
+	if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
 		return 0;
 	return 1;
 }
@@ -3085,12 +3242,10 @@ static int __ext4_normal_writepage(struct page *page,
 	struct inode *inode = page->mapping->host;
 
 	if (test_opt(inode->i_sb, NOBH))
-		return nobh_writepage(page,
-					ext4_normal_get_block_write, wbc);
+		return nobh_writepage(page, noalloc_get_block_write, wbc);
 	else
-		return block_write_full_page(page,
-						ext4_normal_get_block_write,
-						wbc);
+		return block_write_full_page(page, noalloc_get_block_write,
+					     wbc);
 }
 
 static int ext4_normal_writepage(struct page *page,
@@ -3142,7 +3297,7 @@ static int __ext4_journalled_writepage(struct page *page,
 	int err;
 
 	ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
-					ext4_normal_get_block_write);
+				  noalloc_get_block_write);
 	if (ret != 0)
 		goto out_unlock;
 
@@ -3227,9 +3382,8 @@ static int ext4_journalled_writepage(struct page *page,
 		 * really know unless we go poke around in the buffer_heads.
 		 * But block_write_full_page will do the right thing.
 		 */
-		return block_write_full_page(page,
-						ext4_normal_get_block_write,
-						wbc);
+		return block_write_full_page(page, noalloc_get_block_write,
+					     wbc);
 	}
 no_write:
 	redirty_page_for_writepage(wbc, page);
@@ -3973,7 +4127,8 @@ void ext4_truncate(struct inode *inode)
 	if (!ext4_can_truncate(inode))
 		return;
 
-	if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
+	if (ei->i_disksize && inode->i_size == 0 &&
+	    !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
 		ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
 
 	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
@@ -4715,25 +4870,6 @@ int ext4_write_inode(struct inode *inode, int wait)
 	return ext4_force_commit(inode->i_sb);
 }
 
-int __ext4_write_dirty_metadata(struct inode *inode, struct buffer_head *bh)
-{
-	int err = 0;
-
-	mark_buffer_dirty(bh);
-	if (inode && inode_needs_sync(inode)) {
-		sync_dirty_buffer(bh);
-		if (buffer_req(bh) && !buffer_uptodate(bh)) {
-			ext4_error(inode->i_sb, __func__,
-				   "IO error syncing inode, "
-				   "inode=%lu, block=%llu",
-				   inode->i_ino,
-				   (unsigned long long)bh->b_blocknr);
-			err = -EIO;
-		}
-	}
-	return err;
-}
-
 /*
  * ext4_setattr()
  *
@@ -4930,7 +5066,8 @@ static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
  */
 int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
 {
-	int groups, gdpblocks;
+	ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
+	int gdpblocks;
 	int idxblocks;
 	int ret = 0;
 
@@ -4957,8 +5094,8 @@ int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
 		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 > ngroups)
+		groups = ngroups;
 	if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
 		gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
 
@@ -4998,7 +5135,7 @@ int ext4_writepage_trans_blocks(struct inode *inode)
  * 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.
+ * ext4_get_blocks() 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.