]> Pileus Git - ~andy/linux/blobdiff - fs/ext4/inode.c
ext4: check error return from ext4_write_inline_data_end()
[~andy/linux] / fs / ext4 / inode.c
index 3acf353493d466d01aeebe50b119fb74ed5439f0..09942341dfae6daca419b64ed1257e68a8c25979 100644 (file)
@@ -136,9 +136,8 @@ static void ext4_invalidatepage(struct page *page, unsigned int offset,
                                unsigned int length);
 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
-static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
-               struct inode *inode, struct page *page, loff_t from,
-               loff_t length, int flags);
+static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
+                                 int pextents);
 
 /*
  * Test whether an inode is a fast symlink.
@@ -216,7 +215,8 @@ void ext4_evict_inode(struct inode *inode)
                        filemap_write_and_wait(&inode->i_data);
                }
                truncate_inode_pages(&inode->i_data, 0);
-               ext4_ioend_shutdown(inode);
+
+               WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count));
                goto no_delete;
        }
 
@@ -226,8 +226,8 @@ void ext4_evict_inode(struct inode *inode)
        if (ext4_should_order_data(inode))
                ext4_begin_ordered_truncate(inode, 0);
        truncate_inode_pages(&inode->i_data, 0);
-       ext4_ioend_shutdown(inode);
 
+       WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count));
        if (is_bad_inode(inode))
                goto no_delete;
 
@@ -424,66 +424,6 @@ static int __check_block_validity(struct inode *inode, const char *func,
 #define check_block_validity(inode, map)       \
        __check_block_validity((inode), __func__, __LINE__, (map))
 
-/*
- * Return the number of contiguous dirty pages in a given inode
- * starting at page frame idx.
- */
-static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
-                                   unsigned int max_pages)
-{
-       struct address_space *mapping = inode->i_mapping;
-       pgoff_t index;
-       struct pagevec pvec;
-       pgoff_t num = 0;
-       int i, nr_pages, done = 0;
-
-       if (max_pages == 0)
-               return 0;
-       pagevec_init(&pvec, 0);
-       while (!done) {
-               index = idx;
-               nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
-                                             PAGECACHE_TAG_DIRTY,
-                                             (pgoff_t)PAGEVEC_SIZE);
-               if (nr_pages == 0)
-                       break;
-               for (i = 0; i < nr_pages; i++) {
-                       struct page *page = pvec.pages[i];
-                       struct buffer_head *bh, *head;
-
-                       lock_page(page);
-                       if (unlikely(page->mapping != mapping) ||
-                           !PageDirty(page) ||
-                           PageWriteback(page) ||
-                           page->index != idx) {
-                               done = 1;
-                               unlock_page(page);
-                               break;
-                       }
-                       if (page_has_buffers(page)) {
-                               bh = head = page_buffers(page);
-                               do {
-                                       if (!buffer_delay(bh) &&
-                                           !buffer_unwritten(bh))
-                                               done = 1;
-                                       bh = bh->b_this_page;
-                               } while (!done && (bh != head));
-                       }
-                       unlock_page(page);
-                       if (done)
-                               break;
-                       idx++;
-                       num++;
-                       if (num >= max_pages) {
-                               done = 1;
-                               break;
-                       }
-               }
-               pagevec_release(&pvec);
-       }
-       return num;
-}
-
 #ifdef ES_AGGRESSIVE_TEST
 static void ext4_map_blocks_es_recheck(handle_t *handle,
                                       struct inode *inode,
@@ -574,6 +514,8 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
                  "logical block %lu\n", inode->i_ino, flags, map->m_len,
                  (unsigned long) map->m_lblk);
 
+       ext4_es_lru_add(inode);
+
        /* Lookup extent status tree firstly */
        if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
                if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
@@ -1119,10 +1061,13 @@ static int ext4_write_end(struct file *file,
                }
        }
 
-       if (ext4_has_inline_data(inode))
-               copied = ext4_write_inline_data_end(inode, pos, len,
-                                                   copied, page);
-       else
+       if (ext4_has_inline_data(inode)) {
+               ret = ext4_write_inline_data_end(inode, pos, len,
+                                                copied, page);
+               if (ret < 0)
+                       goto errout;
+               copied = ret;
+       } else
                copied = block_write_end(file, mapping, pos,
                                         len, copied, page, fsdata);
 
@@ -1158,8 +1103,6 @@ static int ext4_write_end(struct file *file,
        if (i_size_changed)
                ext4_mark_inode_dirty(handle, inode);
 
-       if (copied < 0)
-               ret = copied;
        if (pos + len > inode->i_size && ext4_can_truncate(inode))
                /* if we have allocated more blocks and copied
                 * less. We will have blocks allocated outside
@@ -1468,140 +1411,43 @@ static void ext4_da_page_release_reservation(struct page *page,
  * Delayed allocation stuff
  */
 
-/*
- * mpage_da_submit_io - walks through extent of pages and try to write
- * them with writepage() call back
- *
- * @mpd->inode: inode
- * @mpd->first_page: first page of the extent
- * @mpd->next_page: page after the last page of the extent
- *
- * By the time mpage_da_submit_io() is called we expect all blocks
- * to be allocated. this may be wrong if allocation failed.
- *
- * As pages are already locked by write_cache_pages(), we can't use it
- */
-static int mpage_da_submit_io(struct mpage_da_data *mpd,
-                             struct ext4_map_blocks *map)
-{
-       struct pagevec pvec;
-       unsigned long index, end;
-       int ret = 0, err, nr_pages, i;
-       struct inode *inode = mpd->inode;
-       struct address_space *mapping = inode->i_mapping;
-       loff_t size = i_size_read(inode);
-       unsigned int len, block_start;
-       struct buffer_head *bh, *page_bufs = NULL;
-       sector_t pblock = 0, cur_logical = 0;
-       struct ext4_io_submit io_submit;
+struct mpage_da_data {
+       struct inode *inode;
+       struct writeback_control *wbc;
 
-       BUG_ON(mpd->next_page <= mpd->first_page);
-       memset(&io_submit, 0, sizeof(io_submit));
+       pgoff_t first_page;     /* The first page to write */
+       pgoff_t next_page;      /* Current page to examine */
+       pgoff_t last_page;      /* Last page to examine */
        /*
-        * We need to start from the first_page to the next_page - 1
-        * to make sure we also write the mapped dirty buffer_heads.
-        * If we look at mpd->b_blocknr we would only be looking
-        * at the currently mapped buffer_heads.
+        * Extent to map - this can be after first_page because that can be
+        * fully mapped. We somewhat abuse m_flags to store whether the extent
+        * is delalloc or unwritten.
         */
-       index = mpd->first_page;
-       end = mpd->next_page - 1;
-
-       pagevec_init(&pvec, 0);
-       while (index <= end) {
-               nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
-               if (nr_pages == 0)
-                       break;
-               for (i = 0; i < nr_pages; i++) {
-                       int skip_page = 0;
-                       struct page *page = pvec.pages[i];
-
-                       index = page->index;
-                       if (index > end)
-                               break;
-
-                       if (index == size >> PAGE_CACHE_SHIFT)
-                               len = size & ~PAGE_CACHE_MASK;
-                       else
-                               len = PAGE_CACHE_SIZE;
-                       if (map) {
-                               cur_logical = index << (PAGE_CACHE_SHIFT -
-                                                       inode->i_blkbits);
-                               pblock = map->m_pblk + (cur_logical -
-                                                       map->m_lblk);
-                       }
-                       index++;
-
-                       BUG_ON(!PageLocked(page));
-                       BUG_ON(PageWriteback(page));
-
-                       bh = page_bufs = page_buffers(page);
-                       block_start = 0;
-                       do {
-                               if (map && (cur_logical >= map->m_lblk) &&
-                                   (cur_logical <= (map->m_lblk +
-                                                    (map->m_len - 1)))) {
-                                       if (buffer_delay(bh)) {
-                                               clear_buffer_delay(bh);
-                                               bh->b_blocknr = pblock;
-                                       }
-                                       if (buffer_unwritten(bh) ||
-                                           buffer_mapped(bh))
-                                               BUG_ON(bh->b_blocknr != pblock);
-                                       if (map->m_flags & EXT4_MAP_UNINIT)
-                                               set_buffer_uninit(bh);
-                                       clear_buffer_unwritten(bh);
-                               }
-
-                               /*
-                                * skip page if block allocation undone and
-                                * block is dirty
-                                */
-                               if (ext4_bh_delay_or_unwritten(NULL, bh))
-                                       skip_page = 1;
-                               bh = bh->b_this_page;
-                               block_start += bh->b_size;
-                               cur_logical++;
-                               pblock++;
-                       } while (bh != page_bufs);
-
-                       if (skip_page) {
-                               unlock_page(page);
-                               continue;
-                       }
-
-                       clear_page_dirty_for_io(page);
-                       err = ext4_bio_write_page(&io_submit, page, len,
-                                                 mpd->wbc);
-                       if (!err)
-                               mpd->pages_written++;
-                       /*
-                        * In error case, we have to continue because
-                        * remaining pages are still locked
-                        */
-                       if (ret == 0)
-                               ret = err;
-               }
-               pagevec_release(&pvec);
-       }
-       ext4_io_submit(&io_submit);
-       return ret;
-}
+       struct ext4_map_blocks map;
+       struct ext4_io_submit io_submit;        /* IO submission data */
+};
 
-static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
+static void mpage_release_unused_pages(struct mpage_da_data *mpd,
+                                      bool invalidate)
 {
        int nr_pages, i;
        pgoff_t index, end;
        struct pagevec pvec;
        struct inode *inode = mpd->inode;
        struct address_space *mapping = inode->i_mapping;
-       ext4_lblk_t start, last;
+
+       /* This is necessary when next_page == 0. */
+       if (mpd->first_page >= mpd->next_page)
+               return;
 
        index = mpd->first_page;
        end   = mpd->next_page - 1;
-
-       start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-       last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-       ext4_es_remove_extent(inode, start, last - start + 1);
+       if (invalidate) {
+               ext4_lblk_t start, last;
+               start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+               last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+               ext4_es_remove_extent(inode, start, last - start + 1);
+       }
 
        pagevec_init(&pvec, 0);
        while (index <= end) {
@@ -1614,14 +1460,15 @@ static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
                                break;
                        BUG_ON(!PageLocked(page));
                        BUG_ON(PageWriteback(page));
-                       block_invalidatepage(page, 0, PAGE_CACHE_SIZE);
-                       ClearPageUptodate(page);
+                       if (invalidate) {
+                               block_invalidatepage(page, 0, PAGE_CACHE_SIZE);
+                               ClearPageUptodate(page);
+                       }
                        unlock_page(page);
                }
                index = pvec.pages[nr_pages - 1]->index + 1;
                pagevec_release(&pvec);
        }
-       return;
 }
 
 static void ext4_print_free_blocks(struct inode *inode)
@@ -1650,215 +1497,6 @@ static void ext4_print_free_blocks(struct inode *inode)
        return;
 }
 
-/*
- * mpage_da_map_and_submit - go through given space, map them
- *       if necessary, and then submit them for I/O
- *
- * @mpd - bh describing space
- *
- * The function skips space we know is already mapped to disk blocks.
- *
- */
-static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
-{
-       int err, blks, get_blocks_flags;
-       struct ext4_map_blocks map, *mapp = NULL;
-       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;
-
-       /*
-        * If the blocks are mapped already, or we couldn't accumulate
-        * any blocks, then proceed immediately to the submission stage.
-        */
-       if ((mpd->b_size == 0) ||
-           ((mpd->b_state  & (1 << BH_Mapped)) &&
-            !(mpd->b_state & (1 << BH_Delay)) &&
-            !(mpd->b_state & (1 << BH_Unwritten))))
-               goto submit_io;
-
-       handle = ext4_journal_current_handle();
-       BUG_ON(!handle);
-
-       /*
-        * Call ext4_map_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_map_blocks()
-        * will set the EXT4_STATE_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.
-        */
-       map.m_lblk = next;
-       map.m_len = max_blocks;
-       /*
-        * We're in delalloc path and it is possible that we're going to
-        * need more metadata blocks than previously reserved. However
-        * we must not fail because we're in writeback and there is
-        * nothing we can do about it so it might result in data loss.
-        * So use reserved blocks to allocate metadata if possible.
-        */
-       get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
-                          EXT4_GET_BLOCKS_METADATA_NOFAIL;
-       if (ext4_should_dioread_nolock(mpd->inode))
-               get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
-       if (mpd->b_state & (1 << BH_Delay))
-               get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
-
-
-       blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
-       if (blks < 0) {
-               struct super_block *sb = mpd->inode->i_sb;
-
-               err = blks;
-               /*
-                * If get block returns EAGAIN or ENOSPC and there
-                * appears to be free blocks we will just let
-                * mpage_da_submit_io() unlock all of the pages.
-                */
-               if (err == -EAGAIN)
-                       goto submit_io;
-
-               if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
-                       mpd->retval = err;
-                       goto submit_io;
-               }
-
-               /*
-                * get block failure will cause us to loop in
-                * writepages, because a_ops->writepage won't be able
-                * to make progress. The page will be redirtied by
-                * writepage and writepages will again try to write
-                * the same.
-                */
-               if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
-                       ext4_msg(sb, KERN_CRIT,
-                                "delayed block allocation failed for inode %lu "
-                                "at logical offset %llu with max blocks %zd "
-                                "with error %d", mpd->inode->i_ino,
-                                (unsigned long long) next,
-                                mpd->b_size >> mpd->inode->i_blkbits, err);
-                       ext4_msg(sb, KERN_CRIT,
-                               "This should not happen!! Data will be lost");
-                       if (err == -ENOSPC)
-                               ext4_print_free_blocks(mpd->inode);
-               }
-               /* invalidate all the pages */
-               ext4_da_block_invalidatepages(mpd);
-
-               /* Mark this page range as having been completed */
-               mpd->io_done = 1;
-               return;
-       }
-       BUG_ON(blks == 0);
-
-       mapp = &map;
-       if (map.m_flags & EXT4_MAP_NEW) {
-               struct block_device *bdev = mpd->inode->i_sb->s_bdev;
-               int i;
-
-               for (i = 0; i < map.m_len; i++)
-                       unmap_underlying_metadata(bdev, map.m_pblk + i);
-       }
-
-       /*
-        * 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);
-               err = ext4_mark_inode_dirty(handle, mpd->inode);
-               if (err)
-                       ext4_error(mpd->inode->i_sb,
-                                  "Failed to mark inode %lu dirty",
-                                  mpd->inode->i_ino);
-       }
-
-submit_io:
-       mpage_da_submit_io(mpd, mapp);
-       mpd->io_done = 1;
-}
-
-#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
-               (1 << BH_Delay) | (1 << BH_Unwritten))
-
-/*
- * mpage_add_bh_to_extent - try to add one more block to extent of blocks
- *
- * @mpd->lbh - extent of blocks
- * @logical - logical number of the block in the file
- * @b_state - b_state of the buffer head added
- *
- * the function is used to collect contig. blocks in same state
- */
-static void mpage_add_bh_to_extent(struct mpage_da_data *mpd, sector_t logical,
-                                  unsigned long b_state)
-{
-       sector_t next;
-       int blkbits = mpd->inode->i_blkbits;
-       int nrblocks = mpd->b_size >> blkbits;
-
-       /*
-        * XXX Don't go larger than mballoc is willing to allocate
-        * This is a stopgap solution.  We eventually need to fold
-        * mpage_da_submit_io() into this function and then call
-        * ext4_map_blocks() multiple times in a loop
-        */
-       if (nrblocks >= (8*1024*1024 >> blkbits))
-               goto flush_it;
-
-       /* check if the reserved journal credits might overflow */
-       if (!ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS)) {
-               if (nrblocks >= EXT4_MAX_TRANS_DATA) {
-                       /*
-                        * With non-extent format we are limited by the journal
-                        * credit available.  Total credit needed to insert
-                        * nrblocks contiguous blocks is dependent on the
-                        * nrblocks.  So limit nrblocks.
-                        */
-                       goto flush_it;
-               }
-       }
-       /*
-        * First block in the extent
-        */
-       if (mpd->b_size == 0) {
-               mpd->b_blocknr = logical;
-               mpd->b_size = 1 << blkbits;
-               mpd->b_state = b_state & BH_FLAGS;
-               return;
-       }
-
-       next = mpd->b_blocknr + nrblocks;
-       /*
-        * Can we merge the block to our big extent?
-        */
-       if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
-               mpd->b_size += 1 << blkbits;
-               return;
-       }
-
-flush_it:
-       /*
-        * We couldn't merge the block to our extent, so we
-        * need to flush current  extent and start new one
-        */
-       mpage_da_map_and_submit(mpd);
-       return;
-}
-
 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
 {
        return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
@@ -1891,6 +1529,8 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
                  "logical block %lu\n", inode->i_ino, map->m_len,
                  (unsigned long) map->m_lblk);
 
+       ext4_es_lru_add(inode);
+
        /* Lookup extent status tree firstly */
        if (ext4_es_lookup_extent(inode, iblock, &es)) {
 
@@ -2164,7 +1804,7 @@ out:
  * lock so we have to do some magic.
  *
  * This function can get called via...
- *   - ext4_da_writepages after taking page lock (have journal handle)
+ *   - ext4_writepages after taking page lock (have journal handle)
  *   - journal_submit_inode_data_buffers (no journal handle)
  *   - shrink_page_list via the kswapd/direct reclaim (no journal handle)
  *   - grab_page_cache when doing write_begin (have journal handle)
@@ -2233,85 +1873,412 @@ static int ext4_writepage(struct page *page,
                        unlock_page(page);
                        return 0;
                }
-       }
-
-       if (PageChecked(page) && ext4_should_journal_data(inode))
+       }
+
+       if (PageChecked(page) && ext4_should_journal_data(inode))
+               /*
+                * It's mmapped pagecache.  Add buffers and journal it.  There
+                * doesn't seem much point in redirtying the page here.
+                */
+               return __ext4_journalled_writepage(page, len);
+
+       ext4_io_submit_init(&io_submit, wbc);
+       io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
+       if (!io_submit.io_end) {
+               redirty_page_for_writepage(wbc, page);
+               unlock_page(page);
+               return -ENOMEM;
+       }
+       ret = ext4_bio_write_page(&io_submit, page, len, wbc);
+       ext4_io_submit(&io_submit);
+       /* Drop io_end reference we got from init */
+       ext4_put_io_end_defer(io_submit.io_end);
+       return ret;
+}
+
+#define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay))
+
+/*
+ * mballoc gives us at most this number of blocks...
+ * XXX: That seems to be only a limitation of ext4_mb_normalize_request().
+ * The rest of mballoc seems to handle chunks upto full group size.
+ */
+#define MAX_WRITEPAGES_EXTENT_LEN 2048
+
+/*
+ * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
+ *
+ * @mpd - extent of blocks
+ * @lblk - logical number of the block in the file
+ * @b_state - b_state of the buffer head added
+ *
+ * the function is used to collect contig. blocks in same state
+ */
+static int mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
+                                 unsigned long b_state)
+{
+       struct ext4_map_blocks *map = &mpd->map;
+
+       /* Don't go larger than mballoc is willing to allocate */
+       if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
+               return 0;
+
+       /* First block in the extent? */
+       if (map->m_len == 0) {
+               map->m_lblk = lblk;
+               map->m_len = 1;
+               map->m_flags = b_state & BH_FLAGS;
+               return 1;
+       }
+
+       /* Can we merge the block to our big extent? */
+       if (lblk == map->m_lblk + map->m_len &&
+           (b_state & BH_FLAGS) == map->m_flags) {
+               map->m_len++;
+               return 1;
+       }
+       return 0;
+}
+
+static bool add_page_bufs_to_extent(struct mpage_da_data *mpd,
+                                   struct buffer_head *head,
+                                   struct buffer_head *bh,
+                                   ext4_lblk_t lblk)
+{
+       struct inode *inode = mpd->inode;
+       ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1)
+                                                       >> inode->i_blkbits;
+
+       do {
+               BUG_ON(buffer_locked(bh));
+
+               if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
+                   (!buffer_delay(bh) && !buffer_unwritten(bh)) ||
+                   lblk >= blocks) {
+                       /* Found extent to map? */
+                       if (mpd->map.m_len)
+                               return false;
+                       if (lblk >= blocks)
+                               return true;
+                       continue;
+               }
+               if (!mpage_add_bh_to_extent(mpd, lblk, bh->b_state))
+                       return false;
+       } while (lblk++, (bh = bh->b_this_page) != head);
+       return true;
+}
+
+static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
+{
+       int len;
+       loff_t size = i_size_read(mpd->inode);
+       int err;
+
+       BUG_ON(page->index != mpd->first_page);
+       if (page->index == size >> PAGE_CACHE_SHIFT)
+               len = size & ~PAGE_CACHE_MASK;
+       else
+               len = PAGE_CACHE_SIZE;
+       clear_page_dirty_for_io(page);
+       err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc);
+       if (!err)
+               mpd->wbc->nr_to_write--;
+       mpd->first_page++;
+
+       return err;
+}
+
+/*
+ * mpage_map_buffers - update buffers corresponding to changed extent and
+ *                    submit fully mapped pages for IO
+ *
+ * @mpd - description of extent to map, on return next extent to map
+ *
+ * Scan buffers corresponding to changed extent (we expect corresponding pages
+ * to be already locked) and update buffer state according to new extent state.
+ * We map delalloc buffers to their physical location, clear unwritten bits,
+ * and mark buffers as uninit when we perform writes to uninitialized extents
+ * and do extent conversion after IO is finished. If the last page is not fully
+ * mapped, we update @map to the next extent in the last page that needs
+ * mapping. Otherwise we submit the page for IO.
+ */
+static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
+{
+       struct pagevec pvec;
+       int nr_pages, i;
+       struct inode *inode = mpd->inode;
+       struct buffer_head *head, *bh;
+       int bpp_bits = PAGE_CACHE_SHIFT - inode->i_blkbits;
+       ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1)
+                                                       >> inode->i_blkbits;
+       pgoff_t start, end;
+       ext4_lblk_t lblk;
+       sector_t pblock;
+       int err;
+
+       start = mpd->map.m_lblk >> bpp_bits;
+       end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
+       lblk = start << bpp_bits;
+       pblock = mpd->map.m_pblk;
+
+       pagevec_init(&pvec, 0);
+       while (start <= end) {
+               nr_pages = pagevec_lookup(&pvec, inode->i_mapping, start,
+                                         PAGEVEC_SIZE);
+               if (nr_pages == 0)
+                       break;
+               for (i = 0; i < nr_pages; i++) {
+                       struct page *page = pvec.pages[i];
+
+                       if (page->index > end)
+                               break;
+                       /* Upto 'end' pages must be contiguous */
+                       BUG_ON(page->index != start);
+                       bh = head = page_buffers(page);
+                       do {
+                               if (lblk < mpd->map.m_lblk)
+                                       continue;
+                               if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
+                                       /*
+                                        * Buffer after end of mapped extent.
+                                        * Find next buffer in the page to map.
+                                        */
+                                       mpd->map.m_len = 0;
+                                       mpd->map.m_flags = 0;
+                                       add_page_bufs_to_extent(mpd, head, bh,
+                                                               lblk);
+                                       pagevec_release(&pvec);
+                                       return 0;
+                               }
+                               if (buffer_delay(bh)) {
+                                       clear_buffer_delay(bh);
+                                       bh->b_blocknr = pblock++;
+                               }
+                               clear_buffer_unwritten(bh);
+                       } while (++lblk < blocks &&
+                                (bh = bh->b_this_page) != head);
+
+                       /*
+                        * FIXME: This is going to break if dioread_nolock
+                        * supports blocksize < pagesize as we will try to
+                        * convert potentially unmapped parts of inode.
+                        */
+                       mpd->io_submit.io_end->size += PAGE_CACHE_SIZE;
+                       /* Page fully mapped - let IO run! */
+                       err = mpage_submit_page(mpd, page);
+                       if (err < 0) {
+                               pagevec_release(&pvec);
+                               return err;
+                       }
+                       start++;
+               }
+               pagevec_release(&pvec);
+       }
+       /* Extent fully mapped and matches with page boundary. We are done. */
+       mpd->map.m_len = 0;
+       mpd->map.m_flags = 0;
+       return 0;
+}
+
+static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
+{
+       struct inode *inode = mpd->inode;
+       struct ext4_map_blocks *map = &mpd->map;
+       int get_blocks_flags;
+       int err;
+
+       trace_ext4_da_write_pages_extent(inode, map);
+       /*
+        * Call ext4_map_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).  It is
+        * possible that we're going to need more metadata blocks than
+        * previously reserved. However we must not fail because we're in
+        * writeback and there is nothing we can do about it so it might result
+        * in data loss.  So use reserved blocks to allocate metadata if
+        * possible.
+        *
+        * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if the blocks
+        * in question are delalloc blocks.  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_map_blocks() will set the EXT4_STATE_DELALLOC_RESERVED flag
+        * once the inode's allocation semaphore is taken.
+        */
+       get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
+                          EXT4_GET_BLOCKS_METADATA_NOFAIL;
+       if (ext4_should_dioread_nolock(inode))
+               get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
+       if (map->m_flags & (1 << BH_Delay))
+               get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
+
+       err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
+       if (err < 0)
+               return err;
+       if (map->m_flags & EXT4_MAP_UNINIT) {
+               if (!mpd->io_submit.io_end->handle &&
+                   ext4_handle_valid(handle)) {
+                       mpd->io_submit.io_end->handle = handle->h_rsv_handle;
+                       handle->h_rsv_handle = NULL;
+               }
+               ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end);
+       }
+
+       BUG_ON(map->m_len == 0);
+       if (map->m_flags & EXT4_MAP_NEW) {
+               struct block_device *bdev = inode->i_sb->s_bdev;
+               int i;
+
+               for (i = 0; i < map->m_len; i++)
+                       unmap_underlying_metadata(bdev, map->m_pblk + i);
+       }
+       return 0;
+}
+
+/*
+ * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
+ *                              mpd->len and submit pages underlying it for IO
+ *
+ * @handle - handle for journal operations
+ * @mpd - extent to map
+ *
+ * The function maps extent starting at mpd->lblk of length mpd->len. If it is
+ * delayed, blocks are allocated, if it is unwritten, we may need to convert
+ * them to initialized or split the described range from larger unwritten
+ * extent. Note that we need not map all the described range since allocation
+ * can return less blocks or the range is covered by more unwritten extents. We
+ * cannot map more because we are limited by reserved transaction credits. On
+ * the other hand we always make sure that the last touched page is fully
+ * mapped so that it can be written out (and thus forward progress is
+ * guaranteed). After mapping we submit all mapped pages for IO.
+ */
+static int mpage_map_and_submit_extent(handle_t *handle,
+                                      struct mpage_da_data *mpd)
+{
+       struct inode *inode = mpd->inode;
+       struct ext4_map_blocks *map = &mpd->map;
+       int err;
+       loff_t disksize;
+
+       mpd->io_submit.io_end->offset =
+                               ((loff_t)map->m_lblk) << inode->i_blkbits;
+       while (map->m_len) {
+               err = mpage_map_one_extent(handle, mpd);
+               if (err < 0) {
+                       struct super_block *sb = inode->i_sb;
+
+                       /*
+                        * Need to commit transaction to free blocks. Let upper
+                        * layers sort it out.
+                        */
+                       if (err == -ENOSPC && ext4_count_free_clusters(sb))
+                               return -ENOSPC;
+
+                       if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
+                               ext4_msg(sb, KERN_CRIT,
+                                        "Delayed block allocation failed for "
+                                        "inode %lu at logical offset %llu with"
+                                        " max blocks %u with error %d",
+                                        inode->i_ino,
+                                        (unsigned long long)map->m_lblk,
+                                        (unsigned)map->m_len, err);
+                               ext4_msg(sb, KERN_CRIT,
+                                        "This should not happen!! Data will "
+                                        "be lost\n");
+                               if (err == -ENOSPC)
+                                       ext4_print_free_blocks(inode);
+                       }
+                       /* invalidate all the pages */
+                       mpage_release_unused_pages(mpd, true);
+                       return err;
+               }
                /*
-                * It's mmapped pagecache.  Add buffers and journal it.  There
-                * doesn't seem much point in redirtying the page here.
+                * Update buffer state, submit mapped pages, and get us new
+                * extent to map
                 */
-               return __ext4_journalled_writepage(page, len);
+               err = mpage_map_and_submit_buffers(mpd);
+               if (err < 0)
+                       return err;
+       }
 
-       memset(&io_submit, 0, sizeof(io_submit));
-       ret = ext4_bio_write_page(&io_submit, page, len, wbc);
-       ext4_io_submit(&io_submit);
-       return ret;
+       /* Update on-disk size after IO is submitted */
+       disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT;
+       if (disksize > i_size_read(inode))
+               disksize = i_size_read(inode);
+       if (disksize > EXT4_I(inode)->i_disksize) {
+               int err2;
+
+               ext4_update_i_disksize(inode, disksize);
+               err2 = ext4_mark_inode_dirty(handle, inode);
+               if (err2)
+                       ext4_error(inode->i_sb,
+                                  "Failed to mark inode %lu dirty",
+                                  inode->i_ino);
+               if (!err)
+                       err = err2;
+       }
+       return err;
 }
 
 /*
- * This is called via ext4_da_writepages() to
- * calculate the total number of credits to reserve to fit
- * a single extent allocation into a single transaction,
- * ext4_da_writpeages() will loop calling this before
- * the block allocation.
+ * Calculate the total number of credits to reserve for one writepages
+ * iteration. This is called from ext4_writepages(). We map an extent of
+ * upto MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
+ * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN +
+ * bpp - 1 blocks in bpp different extents.
  */
-
 static int ext4_da_writepages_trans_blocks(struct inode *inode)
 {
-       int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
-
-       /*
-        * With non-extent format the journal credit needed to
-        * insert nrblocks contiguous block is dependent on
-        * number of contiguous block. So we will limit
-        * number of contiguous block to a sane value
-        */
-       if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
-           (max_blocks > EXT4_MAX_TRANS_DATA))
-               max_blocks = EXT4_MAX_TRANS_DATA;
+       int bpp = ext4_journal_blocks_per_page(inode);
 
-       return ext4_chunk_trans_blocks(inode, max_blocks);
+       return ext4_meta_trans_blocks(inode,
+                               MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp);
 }
 
 /*
- * write_cache_pages_da - walk the list of dirty pages of the given
- * address space and accumulate pages that need writing, and call
- * mpage_da_map_and_submit to map a single contiguous memory region
- * and then write them.
+ * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
+ *                              and underlying extent to map
+ *
+ * @mpd - where to look for pages
+ *
+ * Walk dirty pages in the mapping. If they are fully mapped, submit them for
+ * IO immediately. When we find a page which isn't mapped we start accumulating
+ * extent of buffers underlying these pages that needs mapping (formed by
+ * either delayed or unwritten buffers). We also lock the pages containing
+ * these buffers. The extent found is returned in @mpd structure (starting at
+ * mpd->lblk with length mpd->len blocks).
+ *
+ * Note that this function can attach bios to one io_end structure which are
+ * neither logically nor physically contiguous. Although it may seem as an
+ * unnecessary complication, it is actually inevitable in blocksize < pagesize
+ * case as we need to track IO to all buffers underlying a page in one io_end.
  */
-static int write_cache_pages_da(handle_t *handle,
-                               struct address_space *mapping,
-                               struct writeback_control *wbc,
-                               struct mpage_da_data *mpd,
-                               pgoff_t *done_index)
+static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
 {
-       struct buffer_head      *bh, *head;
-       struct inode            *inode = mapping->host;
-       struct pagevec          pvec;
-       unsigned int            nr_pages;
-       sector_t                logical;
-       pgoff_t                 index, end;
-       long                    nr_to_write = wbc->nr_to_write;
-       int                     i, tag, ret = 0;
-
-       memset(mpd, 0, sizeof(struct mpage_da_data));
-       mpd->wbc = wbc;
-       mpd->inode = inode;
-       pagevec_init(&pvec, 0);
-       index = wbc->range_start >> PAGE_CACHE_SHIFT;
-       end = wbc->range_end >> PAGE_CACHE_SHIFT;
+       struct address_space *mapping = mpd->inode->i_mapping;
+       struct pagevec pvec;
+       unsigned int nr_pages;
+       pgoff_t index = mpd->first_page;
+       pgoff_t end = mpd->last_page;
+       int tag;
+       int i, err = 0;
+       int blkbits = mpd->inode->i_blkbits;
+       ext4_lblk_t lblk;
+       struct buffer_head *head;
 
-       if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+       if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
                tag = PAGECACHE_TAG_TOWRITE;
        else
                tag = PAGECACHE_TAG_DIRTY;
 
-       *done_index = index;
+       pagevec_init(&pvec, 0);
+       mpd->map.m_len = 0;
+       mpd->next_page = index;
        while (index <= end) {
                nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
                              min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
                if (nr_pages == 0)
-                       return 0;
+                       goto out;
 
                for (i = 0; i < nr_pages; i++) {
                        struct page *page = pvec.pages[i];
@@ -2326,31 +2293,21 @@ static int write_cache_pages_da(handle_t *handle,
                        if (page->index > end)
                                goto out;
 
-                       *done_index = page->index + 1;
-
-                       /*
-                        * If we can't merge this page, and we have
-                        * accumulated an contiguous region, write it
-                        */
-                       if ((mpd->next_page != page->index) &&
-                           (mpd->next_page != mpd->first_page)) {
-                               mpage_da_map_and_submit(mpd);
-                               goto ret_extent_tail;
-                       }
+                       /* If we can't merge this page, we are done. */
+                       if (mpd->map.m_len > 0 && mpd->next_page != page->index)
+                               goto out;
 
                        lock_page(page);
-
                        /*
-                        * If the page is no longer dirty, or its
-                        * mapping no longer corresponds to inode we
-                        * are writing (which means it has been
-                        * truncated or invalidated), or the page is
-                        * already under writeback and we are not
-                        * doing a data integrity writeback, skip the page
+                        * If the page is no longer dirty, or its mapping no
+                        * longer corresponds to inode we are writing (which
+                        * means it has been truncated or invalidated), or the
+                        * page is already under writeback and we are not doing
+                        * a data integrity writeback, skip the page
                         */
                        if (!PageDirty(page) ||
                            (PageWriteback(page) &&
-                            (wbc->sync_mode == WB_SYNC_NONE)) ||
+                            (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
                            unlikely(page->mapping != mapping)) {
                                unlock_page(page);
                                continue;
@@ -2359,106 +2316,69 @@ static int write_cache_pages_da(handle_t *handle,
                        wait_on_page_writeback(page);
                        BUG_ON(PageWriteback(page));
 
-                       /*
-                        * If we have inline data and arrive here, it means that
-                        * we will soon create the block for the 1st page, so
-                        * we'd better clear the inline data here.
-                        */
-                       if (ext4_has_inline_data(inode)) {
-                               BUG_ON(ext4_test_inode_state(inode,
-                                               EXT4_STATE_MAY_INLINE_DATA));
-                               ext4_destroy_inline_data(handle, inode);
-                       }
-
-                       if (mpd->next_page != page->index)
+                       if (mpd->map.m_len == 0)
                                mpd->first_page = page->index;
                        mpd->next_page = page->index + 1;
-                       logical = (sector_t) page->index <<
-                               (PAGE_CACHE_SHIFT - inode->i_blkbits);
-
                        /* Add all dirty buffers to mpd */
+                       lblk = ((ext4_lblk_t)page->index) <<
+                               (PAGE_CACHE_SHIFT - blkbits);
                        head = page_buffers(page);
-                       bh = head;
-                       do {
-                               BUG_ON(buffer_locked(bh));
-                               /*
-                                * We need to try to allocate unmapped blocks
-                                * in the same page.  Otherwise we won't make
-                                * progress with the page in ext4_writepage
-                                */
-                               if (ext4_bh_delay_or_unwritten(NULL, bh)) {
-                                       mpage_add_bh_to_extent(mpd, logical,
-                                                              bh->b_state);
-                                       if (mpd->io_done)
-                                               goto ret_extent_tail;
-                               } else if (buffer_dirty(bh) &&
-                                          buffer_mapped(bh)) {
-                                       /*
-                                        * mapped dirty buffer. We need to
-                                        * update the b_state because we look
-                                        * at b_state in mpage_da_map_blocks.
-                                        * We don't update b_size because if we
-                                        * find an unmapped buffer_head later
-                                        * we need to use the b_state flag of
-                                        * that buffer_head.
-                                        */
-                                       if (mpd->b_size == 0)
-                                               mpd->b_state =
-                                                       bh->b_state & BH_FLAGS;
-                               }
-                               logical++;
-                       } while ((bh = bh->b_this_page) != head);
-
-                       if (nr_to_write > 0) {
-                               nr_to_write--;
-                               if (nr_to_write == 0 &&
-                                   wbc->sync_mode == WB_SYNC_NONE)
-                                       /*
-                                        * We stop writing back only if we are
-                                        * not doing integrity sync. In case of
-                                        * integrity sync we have to keep going
-                                        * because someone may be concurrently
-                                        * dirtying pages, and we might have
-                                        * synced a lot of newly appeared dirty
-                                        * pages, but have not synced all of the
-                                        * old dirty pages.
-                                        */
+                       if (!add_page_bufs_to_extent(mpd, head, head, lblk))
+                               goto out;
+                       /* So far everything mapped? Submit the page for IO. */
+                       if (mpd->map.m_len == 0) {
+                               err = mpage_submit_page(mpd, page);
+                               if (err < 0)
                                        goto out;
                        }
+
+                       /*
+                        * Accumulated enough dirty pages? This doesn't apply
+                        * to WB_SYNC_ALL mode. For integrity sync we have to
+                        * keep going because someone may be concurrently
+                        * dirtying pages, and we might have synced a lot of
+                        * newly appeared dirty pages, but have not synced all
+                        * of the old dirty pages.
+                        */
+                       if (mpd->wbc->sync_mode == WB_SYNC_NONE &&
+                           mpd->next_page - mpd->first_page >=
+                                                       mpd->wbc->nr_to_write)
+                               goto out;
                }
                pagevec_release(&pvec);
                cond_resched();
        }
        return 0;
-ret_extent_tail:
-       ret = MPAGE_DA_EXTENT_TAIL;
 out:
        pagevec_release(&pvec);
-       cond_resched();
-       return ret;
+       return err;
 }
 
+static int __writepage(struct page *page, struct writeback_control *wbc,
+                      void *data)
+{
+       struct address_space *mapping = data;
+       int ret = ext4_writepage(page, wbc);
+       mapping_set_error(mapping, ret);
+       return ret;
+}
 
-static int ext4_da_writepages(struct address_space *mapping,
-                             struct writeback_control *wbc)
+static int ext4_writepages(struct address_space *mapping,
+                          struct writeback_control *wbc)
 {
-       pgoff_t index;
+       pgoff_t writeback_index = 0;
+       long nr_to_write = wbc->nr_to_write;
        int range_whole = 0;
+       int cycled = 1;
        handle_t *handle = NULL;
        struct mpage_da_data mpd;
        struct inode *inode = mapping->host;
-       int pages_written = 0;
-       unsigned int max_pages;
-       int range_cyclic, cycled = 1, io_done = 0;
-       int needed_blocks, ret = 0;
-       long desired_nr_to_write, nr_to_writebump = 0;
-       loff_t range_start = wbc->range_start;
+       int needed_blocks, rsv_blocks = 0, ret = 0;
        struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
-       pgoff_t done_index = 0;
-       pgoff_t end;
+       bool done;
        struct blk_plug plug;
 
-       trace_ext4_da_writepages(inode, wbc);
+       trace_ext4_writepages(inode, wbc);
 
        /*
         * No pages to write? This is mainly a kludge to avoid starting
@@ -2468,164 +2388,164 @@ static int ext4_da_writepages(struct address_space *mapping,
        if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
                return 0;
 
+       if (ext4_should_journal_data(inode)) {
+               struct blk_plug plug;
+               int ret;
+
+               blk_start_plug(&plug);
+               ret = write_cache_pages(mapping, wbc, __writepage, mapping);
+               blk_finish_plug(&plug);
+               return ret;
+       }
+
        /*
         * If the filesystem has aborted, it is read-only, so return
         * right away instead of dumping stack traces later on that
         * will obscure the real source of the problem.  We test
         * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
         * the latter could be true if the filesystem is mounted
-        * read-only, and in that case, ext4_da_writepages should
+        * read-only, and in that case, ext4_writepages should
         * *never* be called, so if that ever happens, we would want
         * the stack trace.
         */
        if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
                return -EROFS;
 
+       if (ext4_should_dioread_nolock(inode)) {
+               /*
+                * We may need to convert upto one extent per block in
+                * the page and we may dirty the inode.
+                */
+               rsv_blocks = 1 + (PAGE_CACHE_SIZE >> inode->i_blkbits);
+       }
+
+       /*
+        * If we have inline data and arrive here, it means that
+        * we will soon create the block for the 1st page, so
+        * we'd better clear the inline data here.
+        */
+       if (ext4_has_inline_data(inode)) {
+               /* Just inode will be modified... */
+               handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+               if (IS_ERR(handle)) {
+                       ret = PTR_ERR(handle);
+                       goto out_writepages;
+               }
+               BUG_ON(ext4_test_inode_state(inode,
+                               EXT4_STATE_MAY_INLINE_DATA));
+               ext4_destroy_inline_data(handle, inode);
+               ext4_journal_stop(handle);
+       }
+
        if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
                range_whole = 1;
 
-       range_cyclic = wbc->range_cyclic;
        if (wbc->range_cyclic) {
-               index = mapping->writeback_index;
-               if (index)
+               writeback_index = mapping->writeback_index;
+               if (writeback_index)
                        cycled = 0;
-               wbc->range_start = index << PAGE_CACHE_SHIFT;
-               wbc->range_end  = LLONG_MAX;
-               wbc->range_cyclic = 0;
-               end = -1;
+               mpd.first_page = writeback_index;
+               mpd.last_page = -1;
        } else {
-               index = wbc->range_start >> PAGE_CACHE_SHIFT;
-               end = wbc->range_end >> PAGE_CACHE_SHIFT;
-       }
-
-       /*
-        * This works around two forms of stupidity.  The first is in
-        * the writeback code, which caps the maximum number of pages
-        * written to be 1024 pages.  This is wrong on multiple
-        * levels; different architectues have a different page size,
-        * which changes the maximum amount of data which gets
-        * written.  Secondly, 4 megabytes is way too small.  XFS
-        * forces this value to be 16 megabytes by multiplying
-        * nr_to_write parameter by four, and then relies on its
-        * allocator to allocate larger extents to make them
-        * contiguous.  Unfortunately this brings us to the second
-        * stupidity, which is that ext4's mballoc code only allocates
-        * at most 2048 blocks.  So we force contiguous writes up to
-        * the number of dirty blocks in the inode, or
-        * sbi->max_writeback_mb_bump whichever is smaller.
-        */
-       max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
-       if (!range_cyclic && range_whole) {
-               if (wbc->nr_to_write == LONG_MAX)
-                       desired_nr_to_write = wbc->nr_to_write;
-               else
-                       desired_nr_to_write = wbc->nr_to_write * 8;
-       } else
-               desired_nr_to_write = ext4_num_dirty_pages(inode, index,
-                                                          max_pages);
-       if (desired_nr_to_write > max_pages)
-               desired_nr_to_write = max_pages;
-
-       if (wbc->nr_to_write < desired_nr_to_write) {
-               nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
-               wbc->nr_to_write = desired_nr_to_write;
+               mpd.first_page = wbc->range_start >> PAGE_CACHE_SHIFT;
+               mpd.last_page = wbc->range_end >> PAGE_CACHE_SHIFT;
        }
 
+       mpd.inode = inode;
+       mpd.wbc = wbc;
+       ext4_io_submit_init(&mpd.io_submit, wbc);
 retry:
        if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
-               tag_pages_for_writeback(mapping, index, end);
-
+               tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page);
+       done = false;
        blk_start_plug(&plug);
-       while (!ret && wbc->nr_to_write > 0) {
+       while (!done && mpd.first_page <= mpd.last_page) {
+               /* For each extent of pages we use new io_end */
+               mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
+               if (!mpd.io_submit.io_end) {
+                       ret = -ENOMEM;
+                       break;
+               }
 
                /*
-                * we  insert one extent at a time. So we need
-                * credit needed for single extent allocation.
-                * journalled mode is currently not supported
-                * by delalloc
+                * We have two constraints: We find one extent to map and we
+                * must always write out whole page (makes a difference when
+                * blocksize < pagesize) so that we don't block on IO when we
+                * try to write out the rest of the page. Journalled mode is
+                * not supported by delalloc.
                 */
                BUG_ON(ext4_should_journal_data(inode));
                needed_blocks = ext4_da_writepages_trans_blocks(inode);
 
-               /* start a new transaction*/
-               handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
-                                           needed_blocks);
+               /* start a new transaction */
+               handle = ext4_journal_start_with_reserve(inode,
+                               EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
                if (IS_ERR(handle)) {
                        ret = PTR_ERR(handle);
                        ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
                               "%ld pages, ino %lu; err %d", __func__,
                                wbc->nr_to_write, inode->i_ino, ret);
-                       blk_finish_plug(&plug);
-                       goto out_writepages;
+                       /* Release allocated io_end */
+                       ext4_put_io_end(mpd.io_submit.io_end);
+                       break;
                }
 
-               /*
-                * Now call write_cache_pages_da() to find the next
-                * contiguous region of logical blocks that need
-                * blocks to be allocated by ext4 and submit them.
-                */
-               ret = write_cache_pages_da(handle, mapping,
-                                          wbc, &mpd, &done_index);
-               /*
-                * If we have a contiguous extent of pages and we
-                * haven't done the I/O yet, map the blocks and submit
-                * them for I/O.
-                */
-               if (!mpd.io_done && mpd.next_page != mpd.first_page) {
-                       mpage_da_map_and_submit(&mpd);
-                       ret = MPAGE_DA_EXTENT_TAIL;
+               trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc);
+               ret = mpage_prepare_extent_to_map(&mpd);
+               if (!ret) {
+                       if (mpd.map.m_len)
+                               ret = mpage_map_and_submit_extent(handle, &mpd);
+                       else {
+                               /*
+                                * We scanned the whole range (or exhausted
+                                * nr_to_write), submitted what was mapped and
+                                * didn't find anything needing mapping. We are
+                                * done.
+                                */
+                               done = true;
+                       }
                }
-               trace_ext4_da_write_pages(inode, &mpd);
-               wbc->nr_to_write -= mpd.pages_written;
-
                ext4_journal_stop(handle);
-
-               if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
-                       /* commit the transaction which would
+               /* Submit prepared bio */
+               ext4_io_submit(&mpd.io_submit);
+               /* Unlock pages we didn't use */
+               mpage_release_unused_pages(&mpd, false);
+               /* Drop our io_end reference we got from init */
+               ext4_put_io_end(mpd.io_submit.io_end);
+
+               if (ret == -ENOSPC && sbi->s_journal) {
+                       /*
+                        * Commit the transaction which would
                         * free blocks released in the transaction
                         * and try again
                         */
                        jbd2_journal_force_commit_nested(sbi->s_journal);
                        ret = 0;
-               } else if (ret == MPAGE_DA_EXTENT_TAIL) {
-                       /*
-                        * Got one extent now try with rest of the pages.
-                        * If mpd.retval is set -EIO, journal is aborted.
-                        * So we don't need to write any more.
-                        */
-                       pages_written += mpd.pages_written;
-                       ret = mpd.retval;
-                       io_done = 1;
-               } else if (wbc->nr_to_write)
-                       /*
-                        * There is no more writeout needed
-                        * or we requested for a noblocking writeout
-                        * and we found the device congested
-                        */
+                       continue;
+               }
+               /* Fatal error - ENOMEM, EIO... */
+               if (ret)
                        break;
        }
        blk_finish_plug(&plug);
-       if (!io_done && !cycled) {
+       if (!ret && !cycled) {
                cycled = 1;
-               index = 0;
-               wbc->range_start = index << PAGE_CACHE_SHIFT;
-               wbc->range_end  = mapping->writeback_index - 1;
+               mpd.last_page = writeback_index - 1;
+               mpd.first_page = 0;
                goto retry;
        }
 
        /* Update index */
-       wbc->range_cyclic = range_cyclic;
        if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
                /*
-                * set the writeback_index so that range_cyclic
+                * Set the writeback_index so that range_cyclic
                 * mode will write it back later
                 */
-               mapping->writeback_index = done_index;
+               mapping->writeback_index = mpd.first_page;
 
 out_writepages:
-       wbc->nr_to_write -= nr_to_writebump;
-       wbc->range_start = range_start;
-       trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
+       trace_ext4_writepages_result(inode, wbc, ret,
+                                    nr_to_write - wbc->nr_to_write);
        return ret;
 }
 
@@ -2873,7 +2793,7 @@ int ext4_alloc_da_blocks(struct inode *inode)
         * laptop_mode, not even desirable).  However, to do otherwise
         * would require replicating code paths in:
         *
-        * ext4_da_writepages() ->
+        * ext4_writepages() ->
         *    write_cache_pages() ---> (via passed in callback function)
         *        __mpage_da_writepage() -->
         *           mpage_add_bh_to_extent()
@@ -3079,9 +2999,13 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
        struct inode *inode = file_inode(iocb->ki_filp);
         ext4_io_end_t *io_end = iocb->private;
 
-       /* if not async direct IO or dio with 0 bytes write, just return */
-       if (!io_end || !size)
-               goto out;
+       /* if not async direct IO just return */
+       if (!io_end) {
+               inode_dio_done(inode);
+               if (is_async)
+                       aio_complete(iocb, ret, 0);
+               return;
+       }
 
        ext_debug("ext4_end_io_dio(): io_end 0x%p "
                  "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
@@ -3089,25 +3013,13 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
                  size);
 
        iocb->private = NULL;
-
-       /* if not aio dio with unwritten extents, just free io and return */
-       if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
-               ext4_free_io_end(io_end);
-out:
-               inode_dio_done(inode);
-               if (is_async)
-                       aio_complete(iocb, ret, 0);
-               return;
-       }
-
        io_end->offset = offset;
        io_end->size = size;
        if (is_async) {
                io_end->iocb = iocb;
                io_end->result = ret;
        }
-
-       ext4_add_complete_io(io_end);
+       ext4_put_io_end_defer(io_end);
 }
 
 /*
@@ -3141,6 +3053,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
        get_block_t *get_block_func = NULL;
        int dio_flags = 0;
        loff_t final_size = offset + count;
+       ext4_io_end_t *io_end = NULL;
 
        /* Use the old path for reads and writes beyond i_size. */
        if (rw != WRITE || final_size > inode->i_size)
@@ -3148,11 +3061,18 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
 
        BUG_ON(iocb->private == NULL);
 
+       /*
+        * Make all waiters for direct IO properly wait also for extent
+        * conversion. This also disallows race between truncate() and
+        * overwrite DIO as i_dio_count needs to be incremented under i_mutex.
+        */
+       if (rw == WRITE)
+               atomic_inc(&inode->i_dio_count);
+
        /* If we do a overwrite dio, i_mutex locking can be released */
        overwrite = *((int *)iocb->private);
 
        if (overwrite) {
-               atomic_inc(&inode->i_dio_count);
                down_read(&EXT4_I(inode)->i_data_sem);
                mutex_unlock(&inode->i_mutex);
        }
@@ -3179,13 +3099,16 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
        iocb->private = NULL;
        ext4_inode_aio_set(inode, NULL);
        if (!is_sync_kiocb(iocb)) {
-               ext4_io_end_t *io_end = ext4_init_io_end(inode, GFP_NOFS);
+               io_end = ext4_init_io_end(inode, GFP_NOFS);
                if (!io_end) {
                        ret = -ENOMEM;
                        goto retake_lock;
                }
                io_end->flag |= EXT4_IO_END_DIRECT;
-               iocb->private = io_end;
+               /*
+                * Grab reference for DIO. Will be dropped in ext4_end_io_dio()
+                */
+               iocb->private = ext4_get_io_end(io_end);
                /*
                 * we save the io structure for current async direct
                 * IO, so that later ext4_map_blocks() could flag the
@@ -3209,33 +3132,42 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                                   NULL,
                                   dio_flags);
 
-       if (iocb->private)
-               ext4_inode_aio_set(inode, NULL);
        /*
-        * The io_end structure takes a reference to the inode, that
-        * structure needs to be destroyed and the reference to the
-        * inode need to be dropped, when IO is complete, even with 0
-        * byte write, or failed.
-        *
-        * In the successful AIO DIO case, the io_end structure will
-        * be destroyed and the reference to the inode will be dropped
-        * after the end_io call back function is called.
-        *
-        * In the case there is 0 byte write, or error case, since VFS
-        * direct IO won't invoke the end_io call back function, we
-        * need to free the end_io structure here.
+        * Put our reference to io_end. This can free the io_end structure e.g.
+        * in sync IO case or in case of error. It can even perform extent
+        * conversion if all bios we submitted finished before we got here.
+        * Note that in that case iocb->private can be already set to NULL
+        * here.
         */
-       if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
-               ext4_free_io_end(iocb->private);
-               iocb->private = NULL;
-       } else if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
+       if (io_end) {
+               ext4_inode_aio_set(inode, NULL);
+               ext4_put_io_end(io_end);
+               /*
+                * When no IO was submitted ext4_end_io_dio() was not
+                * called so we have to put iocb's reference.
+                */
+               if (ret <= 0 && ret != -EIOCBQUEUED && iocb->private) {
+                       WARN_ON(iocb->private != io_end);
+                       WARN_ON(io_end->flag & EXT4_IO_END_UNWRITTEN);
+                       WARN_ON(io_end->iocb);
+                       /*
+                        * Generic code already did inode_dio_done() so we
+                        * have to clear EXT4_IO_END_DIRECT to not do it for
+                        * the second time.
+                        */
+                       io_end->flag = 0;
+                       ext4_put_io_end(io_end);
+                       iocb->private = NULL;
+               }
+       }
+       if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
                                                EXT4_STATE_DIO_UNWRITTEN)) {
                int err;
                /*
                 * for non AIO case, since the IO is already
                 * completed, we could do the conversion right here
                 */
-               err = ext4_convert_unwritten_extents(inode,
+               err = ext4_convert_unwritten_extents(NULL, inode,
                                                     offset, ret);
                if (err < 0)
                        ret = err;
@@ -3243,9 +3175,10 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
        }
 
 retake_lock:
+       if (rw == WRITE)
+               inode_dio_done(inode);
        /* take i_mutex locking again if we do a ovewrite dio */
        if (overwrite) {
-               inode_dio_done(inode);
                up_read(&EXT4_I(inode)->i_data_sem);
                mutex_lock(&inode->i_mutex);
        }
@@ -3304,6 +3237,7 @@ static const struct address_space_operations ext4_aops = {
        .readpage               = ext4_readpage,
        .readpages              = ext4_readpages,
        .writepage              = ext4_writepage,
+       .writepages             = ext4_writepages,
        .write_begin            = ext4_write_begin,
        .write_end              = ext4_write_end,
        .bmap                   = ext4_bmap,
@@ -3319,6 +3253,7 @@ static const struct address_space_operations ext4_journalled_aops = {
        .readpage               = ext4_readpage,
        .readpages              = ext4_readpages,
        .writepage              = ext4_writepage,
+       .writepages             = ext4_writepages,
        .write_begin            = ext4_write_begin,
        .write_end              = ext4_journalled_write_end,
        .set_page_dirty         = ext4_journalled_set_page_dirty,
@@ -3334,7 +3269,7 @@ static const struct address_space_operations ext4_da_aops = {
        .readpage               = ext4_readpage,
        .readpages              = ext4_readpages,
        .writepage              = ext4_writepage,
-       .writepages             = ext4_da_writepages,
+       .writepages             = ext4_writepages,
        .write_begin            = ext4_da_write_begin,
        .write_end              = ext4_da_write_end,
        .bmap                   = ext4_bmap,
@@ -3367,209 +3302,6 @@ void ext4_set_aops(struct inode *inode)
                inode->i_mapping->a_ops = &ext4_aops;
 }
 
-
-/*
- * ext4_discard_partial_page_buffers()
- * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
- * This function finds and locks the page containing the offset
- * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
- * Calling functions that already have the page locked should call
- * ext4_discard_partial_page_buffers_no_lock directly.
- */
-int ext4_discard_partial_page_buffers(handle_t *handle,
-               struct address_space *mapping, loff_t from,
-               loff_t length, int flags)
-{
-       struct inode *inode = mapping->host;
-       struct page *page;
-       int err = 0;
-
-       page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
-                                  mapping_gfp_mask(mapping) & ~__GFP_FS);
-       if (!page)
-               return -ENOMEM;
-
-       err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page,
-               from, length, flags);
-
-       unlock_page(page);
-       page_cache_release(page);
-       return err;
-}
-
-/*
- * ext4_discard_partial_page_buffers_no_lock()
- * Zeros a page range of length 'length' starting from offset 'from'.
- * Buffer heads that correspond to the block aligned regions of the
- * zeroed range will be unmapped.  Unblock aligned regions
- * will have the corresponding buffer head mapped if needed so that
- * that region of the page can be updated with the partial zero out.
- *
- * This function assumes that the page has already been  locked.  The
- * The range to be discarded must be contained with in the given page.
- * If the specified range exceeds the end of the page it will be shortened
- * to the end of the page that corresponds to 'from'.  This function is
- * appropriate for updating a page and it buffer heads to be unmapped and
- * zeroed for blocks that have been either released, or are going to be
- * released.
- *
- * handle: The journal handle
- * inode:  The files inode
- * page:   A locked page that contains the offset "from"
- * from:   The starting byte offset (from the beginning of the file)
- *         to begin discarding
- * len:    The length of bytes to discard
- * flags:  Optional flags that may be used:
- *
- *         EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
- *         Only zero the regions of the page whose buffer heads
- *         have already been unmapped.  This flag is appropriate
- *         for updating the contents of a page whose blocks may
- *         have already been released, and we only want to zero
- *         out the regions that correspond to those released blocks.
- *
- * Returns zero on success or negative on failure.
- */
-static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
-               struct inode *inode, struct page *page, loff_t from,
-               loff_t length, int flags)
-{
-       ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
-       unsigned int offset = from & (PAGE_CACHE_SIZE-1);
-       unsigned int blocksize, max, pos;
-       ext4_lblk_t iblock;
-       struct buffer_head *bh;
-       int err = 0;
-
-       blocksize = inode->i_sb->s_blocksize;
-       max = PAGE_CACHE_SIZE - offset;
-
-       if (index != page->index)
-               return -EINVAL;
-
-       /*
-        * correct length if it does not fall between
-        * 'from' and the end of the page
-        */
-       if (length > max || length < 0)
-               length = max;
-
-       iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
-
-       if (!page_has_buffers(page))
-               create_empty_buffers(page, blocksize, 0);
-
-       /* Find the buffer that contains "offset" */
-       bh = page_buffers(page);
-       pos = blocksize;
-       while (offset >= pos) {
-               bh = bh->b_this_page;
-               iblock++;
-               pos += blocksize;
-       }
-
-       pos = offset;
-       while (pos < offset + length) {
-               unsigned int end_of_block, range_to_discard;
-
-               err = 0;
-
-               /* The length of space left to zero and unmap */
-               range_to_discard = offset + length - pos;
-
-               /* The length of space until the end of the block */
-               end_of_block = blocksize - (pos & (blocksize-1));
-
-               /*
-                * Do not unmap or zero past end of block
-                * for this buffer head
-                */
-               if (range_to_discard > end_of_block)
-                       range_to_discard = end_of_block;
-
-
-               /*
-                * Skip this buffer head if we are only zeroing unampped
-                * regions of the page
-                */
-               if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED &&
-                       buffer_mapped(bh))
-                               goto next;
-
-               /* If the range is block aligned, unmap */
-               if (range_to_discard == blocksize) {
-                       clear_buffer_dirty(bh);
-                       bh->b_bdev = NULL;
-                       clear_buffer_mapped(bh);
-                       clear_buffer_req(bh);
-                       clear_buffer_new(bh);
-                       clear_buffer_delay(bh);
-                       clear_buffer_unwritten(bh);
-                       clear_buffer_uptodate(bh);
-                       zero_user(page, pos, range_to_discard);
-                       BUFFER_TRACE(bh, "Buffer discarded");
-                       goto next;
-               }
-
-               /*
-                * If this block is not completely contained in the range
-                * to be discarded, then it is not going to be released. Because
-                * we need to keep this block, we need to make sure this part
-                * of the page is uptodate before we modify it by writeing
-                * partial zeros on it.
-                */
-               if (!buffer_mapped(bh)) {
-                       /*
-                        * Buffer head must be mapped before we can read
-                        * from the block
-                        */
-                       BUFFER_TRACE(bh, "unmapped");
-                       ext4_get_block(inode, iblock, bh, 0);
-                       /* unmapped? It's a hole - nothing to do */
-                       if (!buffer_mapped(bh)) {
-                               BUFFER_TRACE(bh, "still unmapped");
-                               goto next;
-                       }
-               }
-
-               /* Ok, it's mapped. Make sure it's up-to-date */
-               if (PageUptodate(page))
-                       set_buffer_uptodate(bh);
-
-               if (!buffer_uptodate(bh)) {
-                       err = -EIO;
-                       ll_rw_block(READ, 1, &bh);
-                       wait_on_buffer(bh);
-                       /* Uhhuh. Read error. Complain and punt.*/
-                       if (!buffer_uptodate(bh))
-                               goto next;
-               }
-
-               if (ext4_should_journal_data(inode)) {
-                       BUFFER_TRACE(bh, "get write access");
-                       err = ext4_journal_get_write_access(handle, bh);
-                       if (err)
-                               goto next;
-               }
-
-               zero_user(page, pos, range_to_discard);
-
-               err = 0;
-               if (ext4_should_journal_data(inode)) {
-                       err = ext4_handle_dirty_metadata(handle, inode, bh);
-               } else
-                       mark_buffer_dirty(bh);
-
-               BUFFER_TRACE(bh, "Partial buffer zeroed");
-next:
-               bh = bh->b_this_page;
-               iblock++;
-               pos += range_to_discard;
-       }
-
-       return err;
-}
-
 /*
  * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
  * up to the end of the block which corresponds to `from'.
@@ -3637,13 +3369,10 @@ int ext4_block_zero_page_range(handle_t *handle,
                iblock++;
                pos += blocksize;
        }
-
-       err = 0;
        if (buffer_freed(bh)) {
                BUFFER_TRACE(bh, "freed: skip");
                goto unlock;
        }
-
        if (!buffer_mapped(bh)) {
                BUFFER_TRACE(bh, "unmapped");
                ext4_get_block(inode, iblock, bh, 0);
@@ -3666,22 +3395,19 @@ int ext4_block_zero_page_range(handle_t *handle,
                if (!buffer_uptodate(bh))
                        goto unlock;
        }
-
        if (ext4_should_journal_data(inode)) {
                BUFFER_TRACE(bh, "get write access");
                err = ext4_journal_get_write_access(handle, bh);
                if (err)
                        goto unlock;
        }
-
        zero_user(page, offset, length);
-
        BUFFER_TRACE(bh, "zeroed end of block");
 
-       err = 0;
        if (ext4_should_journal_data(inode)) {
                err = ext4_handle_dirty_metadata(handle, inode, bh);
        } else {
+               err = 0;
                mark_buffer_dirty(bh);
                if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE))
                        err = ext4_jbd2_file_inode(handle, inode);
@@ -3750,9 +3476,8 @@ int ext4_can_truncate(struct inode *inode)
  * Returns: 0 on success or negative on failure
  */
 
-int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
+int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 {
-       struct inode *inode = file_inode(file);
        struct super_block *sb = inode->i_sb;
        ext4_lblk_t first_block, stop_block;
        struct address_space *mapping = inode->i_mapping;
@@ -3817,9 +3542,6 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 
        /* Wait all existing dio workers, newcomers will block on i_mutex */
        ext4_inode_block_unlocked_dio(inode);
-       ret = ext4_flush_unwritten_io(inode);
-       if (ret)
-               goto out_dio;
        inode_dio_wait(inode);
 
        if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
@@ -3938,12 +3660,6 @@ void ext4_truncate(struct inode *inode)
                        return;
        }
 
-       /*
-        * finish any pending end_io work so we won't run the risk of
-        * converting any truncated blocks to initialized later
-        */
-       ext4_flush_unwritten_io(inode);
-
        if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
                credits = ext4_writepage_trans_blocks(inode);
        else
@@ -4908,7 +4624,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
                 struct kstat *stat)
 {
        struct inode *inode;
-       unsigned long delalloc_blocks;
+       unsigned long long delalloc_blocks;
 
        inode = dentry->d_inode;
        generic_fillattr(inode, stat);
@@ -4926,15 +4642,16 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
        delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
                                EXT4_I(inode)->i_reserved_data_blocks);
 
-       stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
+       stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits-9);
        return 0;
 }
 
-static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+static int ext4_index_trans_blocks(struct inode *inode, int lblocks,
+                                  int pextents)
 {
        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-               return ext4_ind_trans_blocks(inode, nrblocks, chunk);
-       return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
+               return ext4_ind_trans_blocks(inode, lblocks);
+       return ext4_ext_index_trans_blocks(inode, pextents);
 }
 
 /*
@@ -4948,7 +4665,8 @@ static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
  *
  * Also account for superblock, inode, quota and xattr blocks
  */
-static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
+                                 int pextents)
 {
        ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
        int gdpblocks;
@@ -4956,14 +4674,10 @@ static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
        int ret = 0;
 
        /*
-        * How many index blocks need to touch to modify nrblocks?
-        * The "Chunk" flag indicating whether the nrblocks is
-        * physically contiguous on disk
-        *
-        * For Direct IO and fallocate, they calls get_block to allocate
-        * one single extent at a time, so they could set the "Chunk" flag
+        * How many index blocks need to touch to map @lblocks logical blocks
+        * to @pextents physical extents?
         */
-       idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
+       idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
 
        ret = idxblocks;
 
@@ -4971,12 +4685,7 @@ static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
         * Now let's see how many group bitmaps and group descriptors need
         * to account
         */
-       groups = idxblocks;
-       if (chunk)
-               groups += 1;
-       else
-               groups += nrblocks;
-
+       groups = idxblocks + pextents;
        gdpblocks = groups;
        if (groups > ngroups)
                groups = ngroups;
@@ -5007,7 +4716,7 @@ int ext4_writepage_trans_blocks(struct inode *inode)
        int bpp = ext4_journal_blocks_per_page(inode);
        int ret;
 
-       ret = ext4_meta_trans_blocks(inode, bpp, 0);
+       ret = ext4_meta_trans_blocks(inode, bpp, bpp);
 
        /* Account for data blocks for journalled mode */
        if (ext4_should_journal_data(inode))