1 files changed, 295 insertions, 282 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9f7f9e49914f..50d0e9c64584 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -173,7 +173,7 @@ int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
         BUG_ON(EXT4_JOURNAL(inode) == NULL);
         jbd_debug(2, "restarting handle %p\n", handle);
         up_write(&EXT4_I(inode)->i_data_sem);
-        ret = ext4_journal_restart(handle, blocks_for_truncate(inode));
+        ret = ext4_journal_restart(handle, nblocks);
         down_write(&EXT4_I(inode)->i_data_sem);
         ext4_discard_preallocations(inode);
 
@@ -639,8 +639,8 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
         while (target > 0) {
                 count = target;
                 /* allocating blocks for indirect blocks and direct blocks */
-                current_block = ext4_new_meta_blocks(handle, inode,
-                                                        goal, &count, err);
+                current_block = ext4_new_meta_blocks(handle, inode, goal,
+                                                     0, &count, err);
                 if (*err)
                         goto failed_out;
 
@@ -720,7 +720,7 @@ allocated:
         return ret;
 failed_out:
         for (i = 0; i < index; i++)
-                ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
+                ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
         return ret;
 }
 
@@ -823,20 +823,20 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
         return err;
 failed:
         /* Allocation failed, free what we already allocated */
-        ext4_free_blocks(handle, inode, 0, new_blocks[0], 1, 0);
+        ext4_free_blocks(handle, inode, NULL, new_blocks[0], 1, 0);
         for (i = 1; i <= n ; i++) {
                 /*
                  * branch[i].bh is newly allocated, so there is no
                  * need to revoke the block, which is why we don't
                  * need to set EXT4_FREE_BLOCKS_METADATA.
                  */
-                ext4_free_blocks(handle, inode, 0, new_blocks[i], 1,
+                ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1,
                                  EXT4_FREE_BLOCKS_FORGET);
         }
         for (i = n+1; i < indirect_blks; i++)
-                ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
+                ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
 
-        ext4_free_blocks(handle, inode, 0, new_blocks[i], num, 0);
+        ext4_free_blocks(handle, inode, NULL, new_blocks[i], num, 0);
 
         return err;
 }
@@ -924,7 +924,7 @@ err_out:
                 ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
                                  EXT4_FREE_BLOCKS_FORGET);
         }
-        ext4_free_blocks(handle, inode, 0, le32_to_cpu(where[num].key),
+        ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key),
                          blks, 0);
 
         return err;
@@ -973,6 +973,7 @@ static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
         int count = 0;
         ext4_fsblk_t first_block = 0;
 
+        trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
         J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
         J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
         depth = ext4_block_to_path(inode, map->m_lblk, offsets,
@@ -1058,6 +1059,8 @@ cleanup:
                 partial--;
         }
 out:
+        trace_ext4_ind_map_blocks_exit(inode, map->m_lblk,
+                                map->m_pblk, map->m_len, err);
         return err;
 }
 
@@ -1927,7 +1930,7 @@ repeat:
          * We do still charge estimated metadata to the sb though;
          * we cannot afford to run out of free blocks.
          */
-        if (ext4_claim_free_blocks(sbi, md_needed + 1)) {
+        if (ext4_claim_free_blocks(sbi, md_needed + 1, 0)) {
                 dquot_release_reservation_block(inode, 1);
                 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
                         yield();
@@ -2060,7 +2063,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
                 if (nr_pages == 0)
                         break;
                 for (i = 0; i < nr_pages; i++) {
-                        int commit_write = 0, redirty_page = 0;
+                        int commit_write = 0, skip_page = 0;
                         struct page *page = pvec.pages[i];
 
                         index = page->index;
@@ -2086,14 +2089,12 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
                          * If the page does not have buffers (for
                          * whatever reason), try to create them using
                          * __block_write_begin.  If this fails,
-                         * redirty the page and move on.
+                         * skip the page and move on.
                          */
                         if (!page_has_buffers(page)) {
                                 if (__block_write_begin(page, 0, len,
                                                 noalloc_get_block_write)) {
-                                redirty_page:
-                                        redirty_page_for_writepage(mpd->wbc,
-                                                                   page);
+                                skip_page:
                                         unlock_page(page);
                                         continue;
                                 }
@@ -2104,7 +2105,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
                         block_start = 0;
                         do {
                                 if (!bh)
-                                        goto redirty_page;
+                                        goto skip_page;
                                 if (map && (cur_logical >= map->m_lblk) &&
                                     (cur_logical <= (map->m_lblk +
                                                      (map->m_len - 1)))) {
@@ -2120,22 +2121,23 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
                                         clear_buffer_unwritten(bh);
                                 }
 
-                                /* redirty page if block allocation undone */
+                                /* skip page if block allocation undone */
                                 if (buffer_delay(bh) || buffer_unwritten(bh))
-                                        redirty_page = 1;
+                                        skip_page = 1;
                                 bh = bh->b_this_page;
                                 block_start += bh->b_size;
                                 cur_logical++;
                                 pblock++;
                         } while (bh != page_bufs);
 
-                        if (redirty_page)
-                                goto redirty_page;
+                        if (skip_page)
+                                goto skip_page;
 
                         if (commit_write)
                                 /* mark the buffer_heads as dirty & uptodate */
                                 block_commit_write(page, 0, len);
 
+                        clear_page_dirty_for_io(page);
                         /*
                          * Delalloc doesn't support data journalling,
                          * but eventually maybe we'll lift this
@@ -2165,8 +2167,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
         return ret;
 }
 
-static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
-                                        sector_t logical, long blk_cnt)
+static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
 {
         int nr_pages, i;
         pgoff_t index, end;
@@ -2174,9 +2175,8 @@ static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
         struct inode *inode = mpd->inode;
         struct address_space *mapping = inode->i_mapping;
 
-        index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
-        end   = (logical + blk_cnt - 1) >>
-                                (PAGE_CACHE_SHIFT - inode->i_blkbits);
+        index = mpd->first_page;
+        end   = mpd->next_page - 1;
         while (index <= end) {
                 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
                 if (nr_pages == 0)
@@ -2279,9 +2279,8 @@ static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
                 err = blks;
                 /*
                  * If get block returns EAGAIN or ENOSPC and there
-                 * appears to be free blocks we will call
-                 * ext4_writepage() for all of the pages which will
-                 * just redirty the pages.
+                 * appears to be free blocks we will just let
+                 * mpage_da_submit_io() unlock all of the pages.
                  */
                 if (err == -EAGAIN)
                         goto submit_io;
@@ -2312,8 +2311,10 @@ static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
                                 ext4_print_free_blocks(mpd->inode);
                 }
                 /* invalidate all the pages */
-                ext4_da_block_invalidatepages(mpd, next,
-                                mpd->b_size >> mpd->inode->i_blkbits);
+                ext4_da_block_invalidatepages(mpd);
+
+                /* Mark this page range as having been completed */
+                mpd->io_done = 1;
                 return;
         }
         BUG_ON(blks == 0);
@@ -2438,102 +2439,6 @@ static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
 }
 
 /*
- * __mpage_da_writepage - finds extent of pages and blocks
- *
- * @page: page to consider
- * @wbc: not used, we just follow rules
- * @data: context
- *
- * The function finds extents of pages and scan them for all blocks.
- */
-static int __mpage_da_writepage(struct page *page,
-                                struct writeback_control *wbc,
-                                struct mpage_da_data *mpd)
-{
-        struct inode *inode = mpd->inode;
-        struct buffer_head *bh, *head;
-        sector_t logical;
-
-        /*
-         * Can we merge this page to current extent?
-         */
-        if (mpd->next_page != page->index) {
-                /*
-                 * Nope, we can't. So, we map non-allocated blocks
-                 * and start IO on them
-                 */
-                if (mpd->next_page != mpd->first_page) {
-                        mpage_da_map_and_submit(mpd);
-                        /*
-                         * skip rest of the page in the page_vec
-                         */
-                        redirty_page_for_writepage(wbc, page);
-                        unlock_page(page);
-                        return MPAGE_DA_EXTENT_TAIL;
-                }
-
-                /*
-                 * Start next extent of pages ...
-                 */
-                mpd->first_page = page->index;
-
-                /*
-                 * ... and blocks
-                 */
-                mpd->b_size = 0;
-                mpd->b_state = 0;
-                mpd->b_blocknr = 0;
-        }
-
-        mpd->next_page = page->index + 1;
-        logical = (sector_t) page->index <<
-                  (PAGE_CACHE_SHIFT - inode->i_blkbits);
-
-        if (!page_has_buffers(page)) {
-                mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
-                                       (1 << BH_Dirty) | (1 << BH_Uptodate));
-                if (mpd->io_done)
-                        return MPAGE_DA_EXTENT_TAIL;
-        } else {
-                /*
-                 * Page with regular buffer heads, just add all dirty ones
-                 */
-                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_size,
-                                                       bh->b_state);
-                                if (mpd->io_done)
-                                        return MPAGE_DA_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);
-        }
-
-        return 0;
-}
-
-/*
  * 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.
@@ -2684,7 +2589,7 @@ static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
  * because we should have holes filled from ext4_page_mkwrite(). We even don't
  * need to file the inode to the transaction's list in ordered mode because if
  * we are writing back data added by write(), the inode is already there and if
- * we are writing back data modified via mmap(), noone guarantees in which
+ * we are writing back data modified via mmap(), no one guarantees in which
  * transaction the data will hit the disk. In case we are journaling data, we
  * cannot start transaction directly because transaction start ranks above page
  * lock so we have to do some magic.
@@ -2786,7 +2691,7 @@ static int ext4_writepage(struct page *page,
 
 /*
  * This is called via ext4_da_writepages() to
- * calulate the total number of credits to reserve to fit
+ * 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.
@@ -2811,27 +2716,27 @@ static int ext4_da_writepages_trans_blocks(struct inode *inode)
 
 /*
  * write_cache_pages_da - walk the list of dirty pages of the given
- * address space and call the callback function (which usually writes
- * the pages).
- *
- * This is a forked version of write_cache_pages().  Differences:
- *      Range cyclic is ignored.
- *      no_nrwrite_index_update is always presumed true
+ * 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.
  */
 static int write_cache_pages_da(struct address_space *mapping,
                                 struct writeback_control *wbc,
                                 struct mpage_da_data *mpd,
                                 pgoff_t *done_index)
 {
-        int ret = 0;
-        int done = 0;
-        struct pagevec pvec;
-        unsigned nr_pages;
-        pgoff_t index;
-        pgoff_t end;            /* Inclusive */
-        long nr_to_write = wbc->nr_to_write;
-        int tag;
-
+        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;
@@ -2842,13 +2747,11 @@ static int write_cache_pages_da(struct address_space *mapping,
                 tag = PAGECACHE_TAG_DIRTY;
 
         *done_index = index;
-        while (!done && (index <= end)) {
-                int i;
-
+        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)
-                        break;
+                        return 0;
 
                 for (i = 0; i < nr_pages; i++) {
                         struct page *page = pvec.pages[i];
@@ -2860,60 +2763,98 @@ static int write_cache_pages_da(struct address_space *mapping,
                          * mapping. However, page->index will not change
                          * because we have a reference on the page.
                          */
-                        if (page->index > end) {
-                                done = 1;
-                                break;
-                        }
+                        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;
+                        }
+
                         lock_page(page);
 
                         /*
-                         * Page truncated or invalidated. We can freely skip it
-                         * then, even for data integrity operations: the page
-                         * has disappeared concurrently, so there could be no
-                         * real expectation of this data interity operation
-                         * even if there is now a new, dirty page at the same
-                         * pagecache address.
+                         * 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 (unlikely(page->mapping != mapping)) {
-continue_unlock:
+                        if (!PageDirty(page) ||
+                            (PageWriteback(page) &&
+                             (wbc->sync_mode == WB_SYNC_NONE)) ||
+                            unlikely(page->mapping != mapping)) {
                                 unlock_page(page);
                                 continue;
                         }
 
-                        if (!PageDirty(page)) {
-                                /* someone wrote it for us */
-                                goto continue_unlock;
-                        }
-
-                        if (PageWriteback(page)) {
-                                if (wbc->sync_mode != WB_SYNC_NONE)
-                                        wait_on_page_writeback(page);
-                                else
-                                        goto continue_unlock;
-                        }
-
+                        wait_on_page_writeback(page);
                         BUG_ON(PageWriteback(page));
-                        if (!clear_page_dirty_for_io(page))
-                                goto continue_unlock;
 
-                        ret = __mpage_da_writepage(page, wbc, mpd);
-                        if (unlikely(ret)) {
-                                if (ret == AOP_WRITEPAGE_ACTIVATE) {
-                                        unlock_page(page);
-                                        ret = 0;
-                                } else {
-                                        done = 1;
-                                        break;
-                                }
+                        if (mpd->next_page != page->index)
+                                mpd->first_page = page->index;
+                        mpd->next_page = page->index + 1;
+                        logical = (sector_t) page->index <<
+                                (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+                        if (!page_has_buffers(page)) {
+                                mpage_add_bh_to_extent(mpd, logical,
+                                                       PAGE_CACHE_SIZE,
+                                                       (1 << BH_Dirty) | (1 << BH_Uptodate));
+                                if (mpd->io_done)
+                                        goto ret_extent_tail;
+                        } else {
+                                /*
+                                 * Page with regular buffer heads,
+                                 * just add all dirty ones
+                                 */
+                                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_size,
+                                                                       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) {
+                                    wbc->sync_mode == WB_SYNC_NONE)
                                         /*
                                          * We stop writing back only if we are
                                          * not doing integrity sync. In case of
@@ -2924,14 +2865,18 @@ continue_unlock:
                                          * pages, but have not synced all of the
                                          * old dirty pages.
                                          */
-                                        done = 1;
-                                        break;
-                                }
+                                        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;
 }
 
@@ -2945,7 +2890,6 @@ static int ext4_da_writepages(struct address_space *mapping,
         struct mpage_da_data mpd;
         struct inode *inode = mapping->host;
         int pages_written = 0;
-        long pages_skipped;
         unsigned int max_pages;
         int range_cyclic, cycled = 1, io_done = 0;
         int needed_blocks, ret = 0;
@@ -3028,11 +2972,6 @@ static int ext4_da_writepages(struct address_space *mapping,
                 wbc->nr_to_write = desired_nr_to_write;
         }
 
-        mpd.wbc = wbc;
-        mpd.inode = mapping->host;
-
-        pages_skipped = wbc->pages_skipped;
-
 retry:
         if (wbc->sync_mode == WB_SYNC_ALL)
                 tag_pages_for_writeback(mapping, index, end);
@@ -3059,22 +2998,10 @@ retry:
                 }
 
                 /*
-                 * Now call __mpage_da_writepage to find the next
+                 * Now call write_cache_pages_da() to find the next
                  * contiguous region of logical blocks that need
-                 * blocks to be allocated by ext4.  We don't actually
-                 * submit the blocks for I/O here, even though
-                 * write_cache_pages thinks it will, and will set the
-                 * pages as clean for write before calling
-                 * __mpage_da_writepage().
+                 * blocks to be allocated by ext4 and submit them.
                  */
-                mpd.b_size = 0;
-                mpd.b_state = 0;
-                mpd.b_blocknr = 0;
-                mpd.first_page = 0;
-                mpd.next_page = 0;
-                mpd.io_done = 0;
-                mpd.pages_written = 0;
-                mpd.retval = 0;
                 ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
                 /*
                  * If we have a contiguous extent of pages and we
@@ -3096,7 +3023,6 @@ retry:
                          * and try again
                          */
                         jbd2_journal_force_commit_nested(sbi->s_journal);
-                        wbc->pages_skipped = pages_skipped;
                         ret = 0;
                 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
                         /*
@@ -3104,7 +3030,6 @@ retry:
                          * rest of the pages
                          */
                         pages_written += mpd.pages_written;
-                        wbc->pages_skipped = pages_skipped;
                         ret = 0;
                         io_done = 1;
                 } else if (wbc->nr_to_write)
@@ -3122,11 +3047,6 @@ retry:
                 wbc->range_end  = mapping->writeback_index - 1;
                 goto retry;
         }
-        if (pages_skipped != wbc->pages_skipped)
-                ext4_msg(inode->i_sb, KERN_CRIT,
-                         "This should not happen leaving %s "
-                         "with nr_to_write = %ld ret = %d",
-                         __func__, wbc->nr_to_write, ret);
 
         /* Update index */
         wbc->range_cyclic = range_cyclic;
@@ -3383,7 +3303,7 @@ int ext4_alloc_da_blocks(struct inode *inode)
          * the pages by calling redirty_page_for_writepage() but that
          * would be ugly in the extreme.  So instead we would need to
          * replicate parts of the code in the above functions,
-         * simplifying them becuase we wouldn't actually intend to
+         * simplifying them because we wouldn't actually intend to
          * write out the pages, but rather only collect contiguous
          * logical block extents, call the multi-block allocator, and
          * then update the buffer heads with the block allocations.
@@ -3460,6 +3380,7 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
 
 static int ext4_readpage(struct file *file, struct page *page)
 {
+        trace_ext4_readpage(page);
         return mpage_readpage(page, ext4_get_block);
 }
 
@@ -3494,6 +3415,8 @@ static void ext4_invalidatepage(struct page *page, unsigned long offset)
 {
         journal_t *journal = EXT4_JOURNAL(page->mapping->host);
 
+        trace_ext4_invalidatepage(page, offset);
+
         /*
          * free any io_end structure allocated for buffers to be discarded
          */
@@ -3515,6 +3438,8 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
 {
         journal_t *journal = EXT4_JOURNAL(page->mapping->host);
 
+        trace_ext4_releasepage(page);
+
         WARN_ON(PageChecked(page));
         if (!page_has_buffers(page))
                 return 0;
@@ -3586,7 +3511,7 @@ retry:
                         loff_t end = offset + iov_length(iov, nr_segs);
 
                         if (end > isize)
-                                vmtruncate(inode, isize);
+                                ext4_truncate_failed_write(inode);
                 }
         }
         if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
@@ -3768,7 +3693,7 @@ retry:
  *
  * The unwrritten extents will be converted to written when DIO is completed.
  * For async direct IO, since the IO may still pending when return, we
- * set up an end_io call back function, which will do the convertion
+ * set up an end_io call back function, which will do the conversion
  * when async direct IO completed.
  *
  * If the O_DIRECT write will extend the file then add this inode to the
@@ -3791,7 +3716,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                  * We could direct write to holes and fallocate.
                  *
                  * Allocated blocks to fill the hole are marked as uninitialized
-                 * to prevent paralel buffered read to expose the stale data
+                 * to prevent parallel buffered read to expose the stale data
                  * before DIO complete the data IO.
                  *
                  * As to previously fallocated extents, ext4 get_block
@@ -3852,7 +3777,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                         int err;
                         /*
                          * for non AIO case, since the IO is already
-                         * completed, we could do the convertion right here
+                         * completed, we could do the conversion right here
                          */
                         err = ext4_convert_unwritten_extents(inode,
                                                              offset, ret);
@@ -3873,11 +3798,16 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
+        ssize_t ret;
 
+        trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
         if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
-                return ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
-
-        return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
+                ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
+        else
+                ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
+        trace_ext4_direct_IO_exit(inode, offset,
+                                iov_length(iov, nr_segs), rw, ret);
+        return ret;
 }
 
 /*
@@ -3903,7 +3833,6 @@ static const struct address_space_operations ext4_ordered_aops = {
         .readpage               = ext4_readpage,
         .readpages              = ext4_readpages,
         .writepage              = ext4_writepage,
-        .sync_page              = block_sync_page,
         .write_begin            = ext4_write_begin,
         .write_end              = ext4_ordered_write_end,
         .bmap                   = ext4_bmap,
@@ -3919,7 +3848,6 @@ static const struct address_space_operations ext4_writeback_aops = {
         .readpage               = ext4_readpage,
         .readpages              = ext4_readpages,
         .writepage              = ext4_writepage,
-        .sync_page              = block_sync_page,
         .write_begin            = ext4_write_begin,
         .write_end              = ext4_writeback_write_end,
         .bmap                   = ext4_bmap,
@@ -3935,7 +3863,6 @@ static const struct address_space_operations ext4_journalled_aops = {
         .readpage               = ext4_readpage,
         .readpages              = ext4_readpages,
         .writepage              = ext4_writepage,
-        .sync_page              = block_sync_page,
         .write_begin            = ext4_write_begin,
         .write_end              = ext4_journalled_write_end,
         .set_page_dirty         = ext4_journalled_set_page_dirty,
@@ -3951,7 +3878,6 @@ static const struct address_space_operations ext4_da_aops = {
         .readpages              = ext4_readpages,
         .writepage              = ext4_writepage,
         .writepages             = ext4_da_writepages,
-        .sync_page              = block_sync_page,
         .write_begin            = ext4_da_write_begin,
         .write_end              = ext4_da_write_end,
         .bmap                   = ext4_bmap,
@@ -3988,9 +3914,30 @@ void ext4_set_aops(struct inode *inode)
 int ext4_block_truncate_page(handle_t *handle,
                 struct address_space *mapping, loff_t from)
 {
+        unsigned offset = from & (PAGE_CACHE_SIZE-1);
+        unsigned length;
+        unsigned blocksize;
+        struct inode *inode = mapping->host;
+
+        blocksize = inode->i_sb->s_blocksize;
+        length = blocksize - (offset & (blocksize - 1));
+
+        return ext4_block_zero_page_range(handle, mapping, from, length);
+}
+
+/*
+ * ext4_block_zero_page_range() zeros out a mapping of length 'length'
+ * starting from file offset 'from'.  The range to be zero'd must
+ * be contained with in one block.  If the specified range exceeds
+ * the end of the block it will be shortened to end of the block
+ * that cooresponds to 'from'
+ */
+int ext4_block_zero_page_range(handle_t *handle,
+                struct address_space *mapping, loff_t from, loff_t length)
+{
         ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
         unsigned offset = from & (PAGE_CACHE_SIZE-1);
-        unsigned blocksize, length, pos;
+        unsigned blocksize, max, pos;
         ext4_lblk_t iblock;
         struct inode *inode = mapping->host;
         struct buffer_head *bh;
@@ -4003,7 +3950,15 @@ int ext4_block_truncate_page(handle_t *handle,
                 return -EINVAL;
 
         blocksize = inode->i_sb->s_blocksize;
-        length = blocksize - (offset & (blocksize - 1));
+        max = blocksize - (offset & (blocksize - 1));
+
+        /*
+         * correct length if it does not fall between
+         * 'from' and the end of the block
+         */
+        if (length > max || length < 0)
+                length = max;
+
         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 
         if (!page_has_buffers(page))
@@ -4098,7 +4053,7 @@ static inline int all_zeroes(__le32 *p, __le32 *q)
  *
  *      When we do truncate() we may have to clean the ends of several
  *      indirect blocks but leave the blocks themselves alive. Block is
- *      partially truncated if some data below the new i_size is refered
+ *      partially truncated if some data below the new i_size is referred
  *      from it (and it is on the path to the first completely truncated
  *      data block, indeed).  We have to free the top of that path along
  *      with everything to the right of the path. Since no allocation
@@ -4177,6 +4132,9 @@ no_top:
  *
  * We release `count' blocks on disk, but (last - first) may be greater
  * than `count' because there can be holes in there.
+ *
+ * Return 0 on success, 1 on invalid block range
+ * and < 0 on fatal error.
  */
 static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
                              struct buffer_head *bh,
@@ -4203,33 +4161,32 @@ static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
                 if (bh) {
                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
                         err = ext4_handle_dirty_metadata(handle, inode, bh);
-                        if (unlikely(err)) {
-                                ext4_std_error(inode->i_sb, err);
-                                return 1;
-                        }
+                        if (unlikely(err))
+                                goto out_err;
                 }
                 err = ext4_mark_inode_dirty(handle, inode);
-                if (unlikely(err)) {
-                        ext4_std_error(inode->i_sb, err);
-                        return 1;
-                }
+                if (unlikely(err))
+                        goto out_err;
                 err = ext4_truncate_restart_trans(handle, inode,
                                                   blocks_for_truncate(inode));
-                if (unlikely(err)) {
-                        ext4_std_error(inode->i_sb, err);
-                        return 1;
-                }
+                if (unlikely(err))
+                        goto out_err;
                 if (bh) {
                         BUFFER_TRACE(bh, "retaking write access");
-                        ext4_journal_get_write_access(handle, bh);
+                        err = ext4_journal_get_write_access(handle, bh);
+                        if (unlikely(err))
+                                goto out_err;
                 }
         }
 
         for (p = first; p < last; p++)
                 *p = 0;
 
-        ext4_free_blocks(handle, inode, 0, block_to_free, count, flags);
+        ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
         return 0;
+out_err:
+        ext4_std_error(inode->i_sb, err);
+        return err;
 }
 
 /**
@@ -4240,7 +4197,7 @@ static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
  * @first:      array of block numbers
  * @last:       points immediately past the end of array
  *
- * We are freeing all blocks refered from that array (numbers are stored as
+ * We are freeing all blocks referred from that array (numbers are stored as
  * little-endian 32-bit) and updating @inode->i_blocks appropriately.
  *
  * We accumulate contiguous runs of blocks to free.  Conveniently, if these
@@ -4263,7 +4220,7 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
         ext4_fsblk_t nr;                    /* Current block # */
         __le32 *p;                          /* Pointer into inode/ind
                                                for current block */
-        int err;
+        int err = 0;
 
         if (this_bh) {                          /* For indirect block */
                 BUFFER_TRACE(this_bh, "get_write_access");
@@ -4285,9 +4242,10 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
                         } else if (nr == block_to_free + count) {
                                 count++;
                         } else {
-                                if (ext4_clear_blocks(handle, inode, this_bh,
-                                                      block_to_free, count,
-                                                      block_to_free_p, p))
+                                err = ext4_clear_blocks(handle, inode, this_bh,
+                                                        block_to_free, count,
+                                                        block_to_free_p, p);
+                                if (err)
                                         break;
                                 block_to_free = nr;
                                 block_to_free_p = p;
@@ -4296,9 +4254,12 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
                 }
         }
 
-        if (count > 0)
-                ext4_clear_blocks(handle, inode, this_bh, block_to_free,
-                                  count, block_to_free_p, p);
+        if (!err && count > 0)
+                err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,
+                                        count, block_to_free_p, p);
+        if (err < 0)
+                /* fatal error */
+                return;
 
         if (this_bh) {
                 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
@@ -4328,7 +4289,7 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
  *      @last:  pointer immediately past the end of array
  *      @depth: depth of the branches to free
  *
- *      We are freeing all blocks refered from these branches (numbers are
+ *      We are freeing all blocks referred from these branches (numbers are
  *      stored as little-endian 32-bit) and updating @inode->i_blocks
  *      appropriately.
  */
@@ -4416,7 +4377,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
                          * transaction where the data blocks are
                          * actually freed.
                          */
-                        ext4_free_blocks(handle, inode, 0, nr, 1,
+                        ext4_free_blocks(handle, inode, NULL, nr, 1,
                                          EXT4_FREE_BLOCKS_METADATA|
                                          EXT4_FREE_BLOCKS_FORGET);
 
@@ -4446,8 +4407,6 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 
 int ext4_can_truncate(struct inode *inode)
 {
-        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
-                return 0;
         if (S_ISREG(inode->i_mode))
                 return 1;
         if (S_ISDIR(inode->i_mode))
@@ -4458,6 +4417,31 @@ int ext4_can_truncate(struct inode *inode)
 }
 
 /*
+ * ext4_punch_hole: punches a hole in a file by releaseing the blocks
+ * associated with the given offset and length
+ *
+ * @inode:  File inode
+ * @offset: The offset where the hole will begin
+ * @len:    The length of the hole
+ *
+ * Returns: 0 on sucess or negative on failure
+ */
+
+int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
+{
+        struct inode *inode = file->f_path.dentry->d_inode;
+        if (!S_ISREG(inode->i_mode))
+                return -ENOTSUPP;
+
+        if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+                /* TODO: Add support for non extent hole punching */
+                return -ENOTSUPP;
+        }
+
+        return ext4_ext_punch_hole(file, offset, length);
+}
+
+/*
  * ext4_truncate()
  *
  * We block out ext4_get_block() block instantiations across the entire
@@ -4496,10 +4480,12 @@ void ext4_truncate(struct inode *inode)
         Indirect chain[4];
         Indirect *partial;
         __le32 nr = 0;
-        int n;
-        ext4_lblk_t last_block;
+        int n = 0;
+        ext4_lblk_t last_block, max_block;
         unsigned blocksize = inode->i_sb->s_blocksize;
 
+        trace_ext4_truncate_enter(inode);
+
         if (!ext4_can_truncate(inode))
                 return;
 
@@ -4510,6 +4496,7 @@ void ext4_truncate(struct inode *inode)
 
         if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
                 ext4_ext_truncate(inode);
+                trace_ext4_truncate_exit(inode);
                 return;
         }
 
@@ -4519,14 +4506,18 @@ void ext4_truncate(struct inode *inode)
 
         last_block = (inode->i_size + blocksize-1)
                                         >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+        max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
+                                        >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
 
         if (inode->i_size & (blocksize - 1))
                 if (ext4_block_truncate_page(handle, mapping, inode->i_size))
                         goto out_stop;
 
-        n = ext4_block_to_path(inode, last_block, offsets, NULL);
-        if (n == 0)
-                goto out_stop;  /* error */
+        if (last_block != max_block) {
+                n = ext4_block_to_path(inode, last_block, offsets, NULL);
+                if (n == 0)
+                        goto out_stop;  /* error */
+        }
 
         /*
          * OK.  This truncate is going to happen.  We add the inode to the
@@ -4557,7 +4548,13 @@ void ext4_truncate(struct inode *inode)
          */
         ei->i_disksize = inode->i_size;
 
-        if (n == 1) {           /* direct blocks */
+        if (last_block == max_block) {
+                /*
+                 * It is unnecessary to free any data blocks if last_block is
+                 * equal to the indirect block limit.
+                 */
+                goto out_unlock;
+        } else if (n == 1) {            /* direct blocks */
                 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
                                i_data + EXT4_NDIR_BLOCKS);
                 goto do_indirects;
@@ -4617,6 +4614,7 @@ do_indirects:
                 ;
         }
 
+out_unlock:
         up_write(&ei->i_data_sem);
         inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
         ext4_mark_inode_dirty(handle, inode);
@@ -4639,6 +4637,7 @@ out_stop:
                 ext4_orphan_del(handle, inode);
 
         ext4_journal_stop(handle);
+        trace_ext4_truncate_exit(inode);
 }
 
 /*
@@ -4668,7 +4667,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
         /*
          * Figure out the offset within the block group inode table
          */
-        inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
+        inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
         inode_offset = ((inode->i_ino - 1) %
                         EXT4_INODES_PER_GROUP(sb));
         block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
@@ -4770,6 +4769,7 @@ make_io:
                  * has in-inode xattrs, or we don't have this inode in memory.
                  * Read the block from disk.
                  */
+                trace_ext4_load_inode(inode);
                 get_bh(bh);
                 bh->b_end_io = end_buffer_read_sync;
                 submit_bh(READ_META, bh);
@@ -4875,7 +4875,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                 return inode;
 
         ei = EXT4_I(inode);
-        iloc.bh = 0;
+        iloc.bh = NULL;
 
         ret = __ext4_get_inode_loc(inode, &iloc, 0);
         if (ret < 0)
@@ -5361,8 +5361,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 
         if (S_ISREG(inode->i_mode) &&
             attr->ia_valid & ATTR_SIZE &&
-            (attr->ia_size < inode->i_size ||
-             (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))) {
+            (attr->ia_size < inode->i_size)) {
                 handle_t *handle;
 
                 handle = ext4_journal_start(inode, 3);
@@ -5396,14 +5395,15 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
                                 goto err_out;
                         }
                 }
-                /* ext4_truncate will clear the flag */
-                if ((ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))
-                        ext4_truncate(inode);
         }
 
-        if ((attr->ia_valid & ATTR_SIZE) &&
-            attr->ia_size != i_size_read(inode))
-                rc = vmtruncate(inode, attr->ia_size);
+        if (attr->ia_valid & ATTR_SIZE) {
+                if (attr->ia_size != i_size_read(inode)) {
+                        truncate_setsize(inode, attr->ia_size);
+                        ext4_truncate(inode);
+                } else if (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
+                        ext4_truncate(inode);
+        }
 
         if (!rc) {
                 setattr_copy(inode, attr);
@@ -5460,13 +5460,12 @@ static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
         /* if nrblocks are contiguous */
         if (chunk) {
                 /*
-                 * With N contiguous data blocks, it need at most
-                 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
-                 * 2 dindirect blocks
-                 * 1 tindirect block
+                 * With N contiguous data blocks, we need at most
+                 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+                 * 2 dindirect blocks, and 1 tindirect block
                  */
-                indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
-                return indirects + 3;
+                return DIV_ROUND_UP(nrblocks,
+                                    EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
         }
         /*
          * if nrblocks are not contiguous, worse case, each block touch
@@ -5540,7 +5539,7 @@ static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
 }
 
 /*
- * Calulate the total number of credits to reserve to fit
+ * Calculate the total number of credits to reserve to fit
  * the modification of a single pages into a single transaction,
  * which may include multiple chunks of block allocations.
  *
@@ -5862,15 +5861,19 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
                 goto out_unlock;
         }
         ret = 0;
-        if (PageMappedToDisk(page))
-                goto out_unlock;
+
+        lock_page(page);
+        wait_on_page_writeback(page);
+        if (PageMappedToDisk(page)) {
+                up_read(&inode->i_alloc_sem);
+                return VM_FAULT_LOCKED;
+        }
 
         if (page->index == size >> PAGE_CACHE_SHIFT)
                 len = size & ~PAGE_CACHE_MASK;
         else
                 len = PAGE_CACHE_SIZE;
 
-        lock_page(page);
         /*
          * return if we have all the buffers mapped. This avoid
          * the need to call write_begin/write_end which does a
@@ -5880,8 +5883,8 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         if (page_has_buffers(page)) {
                 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
                                         ext4_bh_unmapped)) {
-                        unlock_page(page);
-                        goto out_unlock;
+                        up_read(&inode->i_alloc_sem);
+                        return VM_FAULT_LOCKED;
                 }
         }
         unlock_page(page);
@@ -5901,6 +5904,16 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         if (ret < 0)
                 goto out_unlock;
         ret = 0;
+
+        /*
+         * write_begin/end might have created a dirty page and someone
+         * could wander in and start the IO.  Make sure that hasn't
+         * happened.
+         */
+        lock_page(page);
+        wait_on_page_writeback(page);
+        up_read(&inode->i_alloc_sem);
+        return VM_FAULT_LOCKED;
 out_unlock:
         if (ret)
                 ret = VM_FAULT_SIGBUS;