---

yaml
---
r: 273129
b: refs/heads/master
c: 5356f26
h: refs/heads/master
i:
  273127: dcba2a5
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d8990240d8c911064447f8aa5a440f9345a6d692
+refs/heads/master: 5356f2615cd558c57a1f7d7528d1ad4de3640d96

trunk/fs/ext4/ext4.h

@@ -1893,7 +1893,6 @@ extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
 extern void ext4_da_update_reserve_space(struct inode *inode,
 					int used, int quota_claim);
-extern int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock);
 
 /* indirect.c */
 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
@@ -2300,10 +2299,14 @@ enum ext4_state_bits {
 				 * never, ever appear in a buffer_head's state
 				 * flag. See EXT4_MAP_FROM_CLUSTER to see where
 				 * this is used. */
+	BH_Da_Mapped,	/* Delayed allocated block that now has a mapping. This
+			 * flag is set when ext4_map_blocks is called on a
+			 * delayed allocated block to get its real mapping. */
 };
 
 BUFFER_FNS(Uninit, uninit)
 TAS_BUFFER_FNS(Uninit, uninit)
+BUFFER_FNS(Da_Mapped, da_mapped)
 
 /*
  * Add new method to test wether block and inode bitmaps are properly

trunk/fs/ext4/extents.c

@@ -3296,28 +3296,9 @@ static int ext4_find_delalloc_range(struct inode *inode,
 
 	while ((i >= lblk_start) && (i <= lblk_end)) {
 		page = find_get_page(mapping, index);
-		if (!page || !PageDirty(page))
+		if (!page)
 			goto nextpage;
 
-		if (PageWriteback(page)) {
-			/*
-			 * This might be a race with allocation and writeout. In
-			 * this case we just assume that the rest of the range
-			 * will eventually be written and there wont be any
-			 * delalloc blocks left.
-			 * TODO: the above assumption is troublesome, but might
-			 * work better in practice. other option could be note
-			 * somewhere that the cluster is getting written out and
-			 * detect that here.
-			 */
-			page_cache_release(page);
-			trace_ext4_find_delalloc_range(inode,
-					lblk_start, lblk_end,
-					search_hint_reverse,
-					0, i);
-			return 0;
-		}
-
 		if (!page_has_buffers(page))
 			goto nextpage;
 
@@ -3340,7 +3321,11 @@ static int ext4_find_delalloc_range(struct inode *inode,
 				continue;
 			}
 
-			if (buffer_delay(bh)) {
+			/* Check if the buffer is delayed allocated and that it
+			 * is not yet mapped. (when da-buffers are mapped during
+			 * their writeout, their da_mapped bit is set.)
+			 */
+			if (buffer_delay(bh) && !buffer_da_mapped(bh)) {
 				page_cache_release(page);
 				trace_ext4_find_delalloc_range(inode,
 						lblk_start, lblk_end,
@@ -4106,6 +4091,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 			ext4_da_update_reserve_space(inode, allocated_clusters,
 							1);
 			if (reserved_clusters < allocated_clusters) {
+				struct ext4_inode_info *ei = EXT4_I(inode);
 				int reservation = allocated_clusters -
 						  reserved_clusters;
 				/*
@@ -4148,11 +4134,11 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 				 *   remaining blocks finally gets written, we
 				 *   could claim them.
 				 */
-				while (reservation) {
-					ext4_da_reserve_space(inode,
-							      map->m_lblk);
-					reservation--;
-				}
+				dquot_reserve_block(inode,
+						EXT4_C2B(sbi, reservation));
+				spin_lock(&ei->i_block_reservation_lock);
+				ei->i_reserved_data_blocks += reservation;
+				spin_unlock(&ei->i_block_reservation_lock);
 			}
 		}
 	}

trunk/fs/ext4/inode.c

@@ -397,6 +397,49 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
 	return num;
 }
 
+/*
+ * Sets the BH_Da_Mapped bit on the buffer heads corresponding to the given map.
+ */
+static void set_buffers_da_mapped(struct inode *inode,
+				   struct ext4_map_blocks *map)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct pagevec pvec;
+	int i, nr_pages;
+	pgoff_t index, end;
+
+	index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	end = (map->m_lblk + map->m_len - 1) >>
+		(PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+	pagevec_init(&pvec, 0);
+	while (index <= end) {
+		nr_pages = pagevec_lookup(&pvec, mapping, index,
+					  min(end - index + 1,
+					      (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;
+
+			if (unlikely(page->mapping != mapping) ||
+			    !PageDirty(page))
+				break;
+
+			if (page_has_buffers(page)) {
+				bh = head = page_buffers(page);
+				do {
+					set_buffer_da_mapped(bh);
+					bh = bh->b_this_page;
+				} while (bh != head);
+			}
+			index++;
+		}
+		pagevec_release(&pvec);
+	}
+}
+
 /*
  * The ext4_map_blocks() function tries to look up the requested blocks,
  * and returns if the blocks are already mapped.
@@ -516,9 +559,17 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 			(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
 			ext4_da_update_reserve_space(inode, retval, 1);
 	}
-	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
 		ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
 
+		/* If we have successfully mapped the delayed allocated blocks,
+		 * set the BH_Da_Mapped bit on them. Its important to do this
+		 * under the protection of i_data_sem.
+		 */
+		if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
+			set_buffers_da_mapped(inode, map);
+	}
+
 	up_write((&EXT4_I(inode)->i_data_sem));
 	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
 		int ret = check_block_validity(inode, map);
@@ -1038,7 +1089,7 @@ static int ext4_journalled_write_end(struct file *file,
 /*
  * Reserve a single cluster located at lblock
  */
-int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
+static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
 {
 	int retries = 0;
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -1153,6 +1204,7 @@ static void ext4_da_page_release_reservation(struct page *page,
 		if ((offset <= curr_off) && (buffer_delay(bh))) {
 			to_release++;
 			clear_buffer_delay(bh);
+			clear_buffer_da_mapped(bh);
 		}
 		curr_off = next_off;
 	} while ((bh = bh->b_this_page) != head);
@@ -1271,6 +1323,8 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
 						clear_buffer_delay(bh);
 						bh->b_blocknr = pblock;
 					}
+					if (buffer_da_mapped(bh))
+						clear_buffer_da_mapped(bh);
 					if (buffer_unwritten(bh) ||
 					    buffer_mapped(bh))
 						BUG_ON(bh->b_blocknr != pblock);
@@ -1603,6 +1657,66 @@ static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
 	return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
 }
 
+/*
+ * This function is grabs code from the very beginning of
+ * ext4_map_blocks, but assumes that the caller is from delayed write
+ * time. This function looks up the requested blocks and sets the
+ * buffer delay bit under the protection of i_data_sem.
+ */
+static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
+			      struct ext4_map_blocks *map,
+			      struct buffer_head *bh)
+{
+	int retval;
+	sector_t invalid_block = ~((sector_t) 0xffff);
+
+	if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
+		invalid_block = ~0;
+
+	map->m_flags = 0;
+	ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
+		  "logical block %lu\n", inode->i_ino, map->m_len,
+		  (unsigned long) map->m_lblk);
+	/*
+	 * Try to see if we can get the block without requesting a new
+	 * file system block.
+	 */
+	down_read((&EXT4_I(inode)->i_data_sem));
+	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		retval = ext4_ext_map_blocks(NULL, inode, map, 0);
+	else
+		retval = ext4_ind_map_blocks(NULL, inode, map, 0);
+
+	if (retval == 0) {
+		/*
+		 * XXX: __block_prepare_write() unmaps passed block,
+		 * is it OK?
+		 */
+		/* If the block was allocated from previously allocated cluster,
+		 * then we dont need to reserve it again. */
+		if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
+			retval = ext4_da_reserve_space(inode, iblock);
+			if (retval)
+				/* not enough space to reserve */
+				goto out_unlock;
+		}
+
+		/* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
+		 * and it should not appear on the bh->b_state.
+		 */
+		map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
+
+		map_bh(bh, inode->i_sb, invalid_block);
+		set_buffer_new(bh);
+		set_buffer_delay(bh);
+	}
+
+out_unlock:
+	up_read((&EXT4_I(inode)->i_data_sem));
+
+	return retval;
+}
+
 /*
  * This is a special get_blocks_t callback which is used by
  * ext4_da_write_begin().  It will either return mapped block or
@@ -1620,10 +1734,6 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 {
 	struct ext4_map_blocks map;
 	int ret = 0;
-	sector_t invalid_block = ~((sector_t) 0xffff);
-
-	if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
-		invalid_block = ~0;
 
 	BUG_ON(create == 0);
 	BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
@@ -1636,29 +1746,9 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 	 * preallocated blocks are unmapped but should treated
 	 * the same as allocated blocks.
 	 */
-	ret = ext4_map_blocks(NULL, inode, &map, 0);
-	if (ret < 0)
+	ret = ext4_da_map_blocks(inode, iblock, &map, bh);
+	if (ret <= 0)
 		return ret;
-	if (ret == 0) {
-		if (buffer_delay(bh))
-			return 0; /* Not sure this could or should happen */
-		/*
-		 * XXX: __block_write_begin() unmaps passed block, is it OK?
-		 */
-		/* If the block was allocated from previously allocated cluster,
-		 * then we dont need to reserve it again. */
-		if (!(map.m_flags & EXT4_MAP_FROM_CLUSTER)) {
-			ret = ext4_da_reserve_space(inode, iblock);
-			if (ret)
-				/* not enough space to reserve */
-				return ret;
-		}
-
-		map_bh(bh, inode->i_sb, invalid_block);
-		set_buffer_new(bh);
-		set_buffer_delay(bh);
-		return 0;
-	}
 
 	map_bh(bh, inode->i_sb, map.m_pblk);
 	bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;