Merge branch 'chandan/prep-subpage-blocksize' into for-chris-4.6

# Conflicts: # fs/btrfs/file.c
2016-02-26 15:38:28 +01:00
parent 388f7b1d6e 65bfa65807
commit 5f1b5664d9
7 changed files with 321 additions and 165 deletions
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -263,7 +263,7 @@ static noinline int cow_file_range_inline(struct btrfs_root *root,
 		data_len = compressed_size;

 	if (start > 0 ||
-	    actual_end > PAGE_CACHE_SIZE ||
+	    actual_end > root->sectorsize ||
 	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
 	    (!compressed_size &&
 	    (actual_end & (root->sectorsize - 1)) == 0) ||
@@ -2002,7 +2002,8 @@ again:
 	if (PagePrivate2(page))
 		goto out;

-	ordered = btrfs_lookup_ordered_extent(inode, page_start);
+	ordered = btrfs_lookup_ordered_range(inode, page_start,
+					PAGE_CACHE_SIZE);
 	if (ordered) {
 		unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
 				     page_end, &cached_state, GFP_NOFS);
@@ -4248,7 +4249,8 @@ static int truncate_inline_extent(struct inode *inode,
 		 * read the extent item from disk (data not in the page cache).
 		 */
 		btrfs_release_path(path);
-		return btrfs_truncate_page(inode, offset, page_end - offset, 0);
+		return btrfs_truncate_block(inode, offset, page_end - offset,
+					0);
 	}

 	btrfs_set_file_extent_ram_bytes(leaf, fi, size);
@@ -4601,17 +4603,17 @@ error:
 }

 /*
- * btrfs_truncate_page - read, zero a chunk and write a page
+ * btrfs_truncate_block - read, zero a chunk and write a block
 * @inode - inode that we're zeroing
 * @from - the offset to start zeroing
 * @len - the length to zero, 0 to zero the entire range respective to the
 *	offset
 * @front - zero up to the offset instead of from the offset on
 *
- * This will find the page for the "from" offset and cow the page and zero the
+ * This will find the block for the "from" offset and cow the block and zero the
 * part we want to zero.  This is used with truncate and hole punching.
 */
-int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
+int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
 			int front)
 {
 	struct address_space *mapping = inode->i_mapping;
@@ -4622,18 +4624,19 @@ int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
 	char *kaddr;
 	u32 blocksize = root->sectorsize;
 	pgoff_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	unsigned offset = from & (blocksize - 1);
 	struct page *page;
 	gfp_t mask = btrfs_alloc_write_mask(mapping);
 	int ret = 0;
-	u64 page_start;
-	u64 page_end;
+	u64 block_start;
+	u64 block_end;

 	if ((offset & (blocksize - 1)) == 0 &&
 	    (!len || ((len & (blocksize - 1)) == 0)))
 		goto out;
+
 	ret = btrfs_delalloc_reserve_space(inode,
-			round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
+			round_down(from, blocksize), blocksize);
 	if (ret)
 		goto out;

@@ -4641,14 +4644,14 @@ again:
 	page = find_or_create_page(mapping, index, mask);
 	if (!page) {
 		btrfs_delalloc_release_space(inode,
-				round_down(from, PAGE_CACHE_SIZE),
-				PAGE_CACHE_SIZE);
+				round_down(from, blocksize),
+				blocksize);
 		ret = -ENOMEM;
 		goto out;
 	}

-	page_start = page_offset(page);
-	page_end = page_start + PAGE_CACHE_SIZE - 1;
+	block_start = round_down(from, blocksize);
+	block_end = block_start + blocksize - 1;

 	if (!PageUptodate(page)) {
 		ret = btrfs_readpage(NULL, page);
@@ -4665,12 +4668,12 @@ again:
 	}
 	wait_on_page_writeback(page);

-	lock_extent_bits(io_tree, page_start, page_end, &cached_state);
+	lock_extent_bits(io_tree, block_start, block_end, &cached_state);
 	set_page_extent_mapped(page);

-	ordered = btrfs_lookup_ordered_extent(inode, page_start);
+	ordered = btrfs_lookup_ordered_extent(inode, block_start);
 	if (ordered) {
-		unlock_extent_cached(io_tree, page_start, page_end,
+		unlock_extent_cached(io_tree, block_start, block_end,
 				     &cached_state, GFP_NOFS);
 		unlock_page(page);
 		page_cache_release(page);
@@ -4679,39 +4682,41 @@ again:
 		goto again;
 	}

-	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+	clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
 			  EXTENT_DIRTY | EXTENT_DELALLOC |
 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
 			  0, 0, &cached_state, GFP_NOFS);

-	ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
+	ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
 					&cached_state);
 	if (ret) {
-		unlock_extent_cached(io_tree, page_start, page_end,
+		unlock_extent_cached(io_tree, block_start, block_end,
 				     &cached_state, GFP_NOFS);
 		goto out_unlock;
 	}

-	if (offset != PAGE_CACHE_SIZE) {
+	if (offset != blocksize) {
 		if (!len)
-			len = PAGE_CACHE_SIZE - offset;
+			len = blocksize - offset;
 		kaddr = kmap(page);
 		if (front)
-			memset(kaddr, 0, offset);
+			memset(kaddr + (block_start - page_offset(page)),
+				0, offset);
 		else
-			memset(kaddr + offset, 0, len);
+			memset(kaddr + (block_start - page_offset(page)) +  offset,
+				0, len);
 		flush_dcache_page(page);
 		kunmap(page);
 	}
 	ClearPageChecked(page);
 	set_page_dirty(page);
-	unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
+	unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
 			     GFP_NOFS);

 out_unlock:
 	if (ret)
-		btrfs_delalloc_release_space(inode, page_start,
-					     PAGE_CACHE_SIZE);
+		btrfs_delalloc_release_space(inode, block_start,
+					     blocksize);
 	unlock_page(page);
 	page_cache_release(page);
 out:
@@ -4782,11 +4787,11 @@ int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
 	int err = 0;

 	/*
-	 * If our size started in the middle of a page we need to zero out the
-	 * rest of the page before we expand the i_size, otherwise we could
+	 * If our size started in the middle of a block we need to zero out the
+	 * rest of the block before we expand the i_size, otherwise we could
 	 * expose stale data.
 	 */
-	err = btrfs_truncate_page(inode, oldsize, 0, 0);
+	err = btrfs_truncate_block(inode, oldsize, 0, 0);
 	if (err)
 		return err;

@@ -4895,7 +4900,6 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
 	}

 	if (newsize > oldsize) {
-		truncate_pagecache(inode, newsize);
 		/*
 		 * Don't do an expanding truncate while snapshoting is ongoing.
 		 * This is to ensure the snapshot captures a fully consistent
@@ -4918,6 +4922,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)

 		i_size_write(inode, newsize);
 		btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
+		pagecache_isize_extended(inode, oldsize, newsize);
 		ret = btrfs_update_inode(trans, root, inode);
 		btrfs_end_write_no_snapshoting(root);
 		btrfs_end_transaction(trans, root);
@@ -7752,9 +7757,9 @@ static int btrfs_check_dio_repairable(struct inode *inode,
 }

 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
-			  struct page *page, u64 start, u64 end,
-			  int failed_mirror, bio_end_io_t *repair_endio,
-			  void *repair_arg)
+			struct page *page, unsigned int pgoff,
+			u64 start, u64 end, int failed_mirror,
+			bio_end_io_t *repair_endio, void *repair_arg)
 {
 	struct io_failure_record *failrec;
 	struct bio *bio;
@@ -7775,7 +7780,9 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
 		return -EIO;
 	}

-	if (failed_bio->bi_vcnt > 1)
+	if ((failed_bio->bi_vcnt > 1)
+		|| (failed_bio->bi_io_vec->bv_len
+			> BTRFS_I(inode)->root->sectorsize))
 		read_mode = READ_SYNC | REQ_FAILFAST_DEV;
 	else
 		read_mode = READ_SYNC;
@@ -7783,7 +7790,7 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
 	isector = start - btrfs_io_bio(failed_bio)->logical;
 	isector >>= inode->i_sb->s_blocksize_bits;
 	bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
-				      0, isector, repair_endio, repair_arg);
+				pgoff, isector, repair_endio, repair_arg);
 	if (!bio) {
 		free_io_failure(inode, failrec);
 		return -EIO;
@@ -7813,12 +7820,17 @@ struct btrfs_retry_complete {
 static void btrfs_retry_endio_nocsum(struct bio *bio)
 {
 	struct btrfs_retry_complete *done = bio->bi_private;
+	struct inode *inode;
 	struct bio_vec *bvec;
 	int i;

 	if (bio->bi_error)
 		goto end;

+	ASSERT(bio->bi_vcnt == 1);
+	inode = bio->bi_io_vec->bv_page->mapping->host;
+	ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
+
 	done->uptodate = 1;
 	bio_for_each_segment_all(bvec, bio, i)
 		clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
@@ -7830,25 +7842,35 @@ end:
 static int __btrfs_correct_data_nocsum(struct inode *inode,
 				       struct btrfs_io_bio *io_bio)
 {
+	struct btrfs_fs_info *fs_info;
 	struct bio_vec *bvec;
 	struct btrfs_retry_complete done;
 	u64 start;
+	unsigned int pgoff;
+	u32 sectorsize;
+	int nr_sectors;
 	int i;
 	int ret;

+	fs_info = BTRFS_I(inode)->root->fs_info;
+	sectorsize = BTRFS_I(inode)->root->sectorsize;
+
 	start = io_bio->logical;
 	done.inode = inode;

 	bio_for_each_segment_all(bvec, &io_bio->bio, i) {
-try_again:
+		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
+		pgoff = bvec->bv_offset;
+
+next_block_or_try_again:
 		done.uptodate = 0;
 		done.start = start;
 		init_completion(&done.done);

-		ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
-				     start + bvec->bv_len - 1,
-				     io_bio->mirror_num,
-				     btrfs_retry_endio_nocsum, &done);
+		ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
+				pgoff, start, start + sectorsize - 1,
+				io_bio->mirror_num,
+				btrfs_retry_endio_nocsum, &done);
 		if (ret)
 			return ret;

@@ -7856,10 +7878,15 @@ try_again:

 		if (!done.uptodate) {
 			/* We might have another mirror, so try again */
-			goto try_again;
+			goto next_block_or_try_again;
 		}

-		start += bvec->bv_len;
+		start += sectorsize;
+
+		if (nr_sectors--) {
+			pgoff += sectorsize;
+			goto next_block_or_try_again;
+		}
 	}

 	return 0;
@@ -7869,7 +7896,9 @@ static void btrfs_retry_endio(struct bio *bio)
 {
 	struct btrfs_retry_complete *done = bio->bi_private;
 	struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
+	struct inode *inode;
 	struct bio_vec *bvec;
+	u64 start;
 	int uptodate;
 	int ret;
 	int i;
@@ -7878,13 +7907,20 @@ static void btrfs_retry_endio(struct bio *bio)
 		goto end;

 	uptodate = 1;
+
+	start = done->start;
+
+	ASSERT(bio->bi_vcnt == 1);
+	inode = bio->bi_io_vec->bv_page->mapping->host;
+	ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
+
 	bio_for_each_segment_all(bvec, bio, i) {
 		ret = __readpage_endio_check(done->inode, io_bio, i,
-					     bvec->bv_page, 0,
-					     done->start, bvec->bv_len);
+					bvec->bv_page, bvec->bv_offset,
+					done->start, bvec->bv_len);
 		if (!ret)
 			clean_io_failure(done->inode, done->start,
-					 bvec->bv_page, 0);
+					bvec->bv_page, bvec->bv_offset);
 		else
 			uptodate = 0;
 	}
@@ -7898,20 +7934,34 @@ end:
 static int __btrfs_subio_endio_read(struct inode *inode,
 				    struct btrfs_io_bio *io_bio, int err)
 {
+	struct btrfs_fs_info *fs_info;
 	struct bio_vec *bvec;
 	struct btrfs_retry_complete done;
 	u64 start;
 	u64 offset = 0;
+	u32 sectorsize;
+	int nr_sectors;
+	unsigned int pgoff;
+	int csum_pos;
 	int i;
 	int ret;

+	fs_info = BTRFS_I(inode)->root->fs_info;
+	sectorsize = BTRFS_I(inode)->root->sectorsize;
+
 	err = 0;
 	start = io_bio->logical;
 	done.inode = inode;

 	bio_for_each_segment_all(bvec, &io_bio->bio, i) {
-		ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
-					     0, start, bvec->bv_len);
+		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
+
+		pgoff = bvec->bv_offset;
+next_block:
+		csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
+		ret = __readpage_endio_check(inode, io_bio, csum_pos,
+					bvec->bv_page, pgoff, start,
+					sectorsize);
 		if (likely(!ret))
 			goto next;
 try_again:
@@ -7919,10 +7969,10 @@ try_again:
 		done.start = start;
 		init_completion(&done.done);

-		ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
-				     start + bvec->bv_len - 1,
-				     io_bio->mirror_num,
-				     btrfs_retry_endio, &done);
+		ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
+				pgoff, start, start + sectorsize - 1,
+				io_bio->mirror_num,
+				btrfs_retry_endio, &done);
 		if (ret) {
 			err = ret;
 			goto next;
@@ -7935,8 +7985,15 @@ try_again:
 			goto try_again;
 		}
 next:
-		offset += bvec->bv_len;
-		start += bvec->bv_len;
+		offset += sectorsize;
+		start += sectorsize;
+
+		ASSERT(nr_sectors);
+
+		if (--nr_sectors) {
+			pgoff += sectorsize;
+			goto next_block;
+		}
 	}

 	return err;
@@ -8188,9 +8245,11 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 	u64 file_offset = dip->logical_offset;
 	u64 submit_len = 0;
 	u64 map_length;
-	int nr_pages = 0;
-	int ret;
+	u32 blocksize = root->sectorsize;
 	int async_submit = 0;
+	int nr_sectors;
+	int ret;
+	int i;

 	map_length = orig_bio->bi_iter.bi_size;
 	ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
@@ -8220,9 +8279,12 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 	atomic_inc(&dip->pending_bios);

 	while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
-		if (map_length < submit_len + bvec->bv_len ||
-		    bio_add_page(bio, bvec->bv_page, bvec->bv_len,
-				 bvec->bv_offset) < bvec->bv_len) {
+		nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
+		i = 0;
+next_block:
+		if (unlikely(map_length < submit_len + blocksize ||
+		    bio_add_page(bio, bvec->bv_page, blocksize,
+			    bvec->bv_offset + (i * blocksize)) < blocksize)) {
 			/*
 			 * inc the count before we submit the bio so
 			 * we know the end IO handler won't happen before
@@ -8243,7 +8305,6 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 			file_offset += submit_len;

 			submit_len = 0;
-			nr_pages = 0;

 			bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
 						  start_sector, GFP_NOFS);
@@ -8261,9 +8322,14 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 				bio_put(bio);
 				goto out_err;
 			}
+
+			goto next_block;
 		} else {
-			submit_len += bvec->bv_len;
-			nr_pages++;
+			submit_len += blocksize;
+			if (--nr_sectors) {
+				i++;
+				goto next_block;
+			}
 			bvec++;
 		}
 	}
@@ -8628,6 +8694,8 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 	struct extent_state *cached_state = NULL;
 	u64 page_start = page_offset(page);
 	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
+	u64 start;
+	u64 end;
 	int inode_evicting = inode->i_state & I_FREEING;

 	/*
@@ -8647,14 +8715,18 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,

 	if (!inode_evicting)
 		lock_extent_bits(tree, page_start, page_end, &cached_state);
-	ordered = btrfs_lookup_ordered_extent(inode, page_start);
+again:
+	start = page_start;
+	ordered = btrfs_lookup_ordered_range(inode, start,
+					page_end - start + 1);
 	if (ordered) {
+		end = min(page_end, ordered->file_offset + ordered->len - 1);
 		/*
 		 * IO on this page will never be started, so we need
 		 * to account for any ordered extents now
 		 */
 		if (!inode_evicting)
-			clear_extent_bit(tree, page_start, page_end,
+			clear_extent_bit(tree, start, end,
 					 EXTENT_DIRTY | EXTENT_DELALLOC |
 					 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
 					 EXTENT_DEFRAG, 1, 0, &cached_state,
@@ -8671,22 +8743,26 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,

 			spin_lock_irq(&tree->lock);
 			set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
-			new_len = page_start - ordered->file_offset;
+			new_len = start - ordered->file_offset;
 			if (new_len < ordered->truncated_len)
 				ordered->truncated_len = new_len;
 			spin_unlock_irq(&tree->lock);

 			if (btrfs_dec_test_ordered_pending(inode, &ordered,
-							   page_start,
-							   PAGE_CACHE_SIZE, 1))
+							   start,
+							   end - start + 1, 1))
 				btrfs_finish_ordered_io(ordered);
 		}
 		btrfs_put_ordered_extent(ordered);
 		if (!inode_evicting) {
 			cached_state = NULL;
-			lock_extent_bits(tree, page_start, page_end,
+			lock_extent_bits(tree, start, end,
 					 &cached_state);
 		}
+
+		start = end + 1;
+		if (start < page_end)
+			goto again;
 	}

 	/*
@@ -8747,15 +8823,28 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	loff_t size;
 	int ret;
 	int reserved = 0;
+	u64 reserved_space;
 	u64 page_start;
 	u64 page_end;
+	u64 end;
+
+	reserved_space = PAGE_CACHE_SIZE;

 	sb_start_pagefault(inode->i_sb);
 	page_start = page_offset(page);
 	page_end = page_start + PAGE_CACHE_SIZE - 1;
+	end = page_end;

+	/*
+	 * Reserving delalloc space after obtaining the page lock can lead to
+	 * deadlock. For example, if a dirty page is locked by this function
+	 * and the call to btrfs_delalloc_reserve_space() ends up triggering
+	 * dirty page write out, then the btrfs_writepage() function could
+	 * end up waiting indefinitely to get a lock on the page currently
+	 * being processed by btrfs_page_mkwrite() function.
+	 */
 	ret = btrfs_delalloc_reserve_space(inode, page_start,
-					   PAGE_CACHE_SIZE);
+					   reserved_space);
 	if (!ret) {
 		ret = file_update_time(vma->vm_file);
 		reserved = 1;
@@ -8789,7 +8878,7 @@ again:
 	 * we can't set the delalloc bits if there are pending ordered
 	 * extents.  Drop our locks and wait for them to finish
 	 */
-	ordered = btrfs_lookup_ordered_extent(inode, page_start);
+	ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
 	if (ordered) {
 		unlock_extent_cached(io_tree, page_start, page_end,
 				     &cached_state, GFP_NOFS);
@@ -8799,6 +8888,18 @@ again:
 		goto again;
 	}

+	if (page->index == ((size - 1) >> PAGE_CACHE_SHIFT)) {
+		reserved_space = round_up(size - page_start, root->sectorsize);
+		if (reserved_space < PAGE_CACHE_SIZE) {
+			end = page_start + reserved_space - 1;
+			spin_lock(&BTRFS_I(inode)->lock);
+			BTRFS_I(inode)->outstanding_extents++;
+			spin_unlock(&BTRFS_I(inode)->lock);
+			btrfs_delalloc_release_space(inode, page_start,
+						PAGE_CACHE_SIZE - reserved_space);
+		}
+	}
+
 	/*
 	 * XXX - page_mkwrite gets called every time the page is dirtied, even
 	 * if it was already dirty, so for space accounting reasons we need to
@@ -8806,12 +8907,12 @@ again:
 	 * is probably a better way to do this, but for now keep consistent with
 	 * prepare_pages in the normal write path.
 	 */
-	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
 			  EXTENT_DIRTY | EXTENT_DELALLOC |
 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
 			  0, 0, &cached_state, GFP_NOFS);

-	ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
+	ret = btrfs_set_extent_delalloc(inode, page_start, end,
 					&cached_state);
 	if (ret) {
 		unlock_extent_cached(io_tree, page_start, page_end,
@@ -8850,7 +8951,7 @@ out_unlock:
 	}
 	unlock_page(page);
 out:
-	btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE);
+	btrfs_delalloc_release_space(inode, page_start, reserved_space);
 out_noreserve:
 	sb_end_pagefault(inode->i_sb);
 	return ret;
@@ -9236,7 +9337,6 @@ static int btrfs_getattr(struct vfsmount *mnt,

 	generic_fillattr(inode, stat);
 	stat->dev = BTRFS_I(inode)->root->anon_dev;
-	stat->blksize = PAGE_CACHE_SIZE;

 	spin_lock(&BTRFS_I(inode)->lock);
 	delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;