1 files changed, 57 insertions, 50 deletions

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 7cd4afa4de1d..1f8493a56e8f 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -17,27 +17,23 @@
  * get_ext_path() - Find an extent path for designated logical block number.
  * @inode:	inode to be searched
  * @lblock:	logical block number to find an extent path
- * @ppath:	pointer to an extent path pointer (for output)
+ * @path:	pointer to an extent path
  *
- * ext4_find_extent wrapper. Return 0 on success, or a negative error value
- * on failure.
+ * ext4_find_extent wrapper. Return an extent path pointer on success,
+ * or an error pointer on failure.
  */
-static inline int
+static inline struct ext4_ext_path *
 get_ext_path(struct inode *inode, ext4_lblk_t lblock,
-		struct ext4_ext_path **ppath)
+	     struct ext4_ext_path *path)
 {
-	struct ext4_ext_path *path;
-
-	path = ext4_find_extent(inode, lblock, ppath, EXT4_EX_NOCACHE);
+	path = ext4_find_extent(inode, lblock, path, EXT4_EX_NOCACHE);
 	if (IS_ERR(path))
-		return PTR_ERR(path);
+		return path;
 	if (path[ext_depth(inode)].p_ext == NULL) {
 		ext4_free_ext_path(path);
-		*ppath = NULL;
-		return -ENODATA;
+		return ERR_PTR(-ENODATA);
 	}
-	*ppath = path;
-	return 0;
+	return path;
 }
 
 /**
@@ -95,9 +91,11 @@ mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,
 	int ret = 0;
 	ext4_lblk_t last = from + count;
 	while (from < last) {
-		*err = get_ext_path(inode, from, &path);
-		if (*err)
-			goto out;
+		path = get_ext_path(inode, from, path);
+		if (IS_ERR(path)) {
+			*err = PTR_ERR(path);
+			return ret;
+		}
 		ext = path[ext_depth(inode)].p_ext;
 		if (unwritten != ext4_ext_is_unwritten(ext))
 			goto out;
@@ -166,15 +164,16 @@ mext_folio_double_lock(struct inode *inode1, struct inode *inode2,
 	return 0;
 }
 
-/* Force page buffers uptodate w/o dropping page's lock */
-static int
-mext_page_mkuptodate(struct folio *folio, unsigned from, unsigned to)
+/* Force folio buffers uptodate w/o dropping folio's lock */
+static int mext_page_mkuptodate(struct folio *folio, size_t from, size_t to)
 {
 	struct inode *inode = folio->mapping->host;
 	sector_t block;
-	struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
+	struct buffer_head *bh, *head;
 	unsigned int blocksize, block_start, block_end;
-	int i, err,  nr = 0, partial = 0;
+	int nr = 0;
+	bool partial = false;
+
 	BUG_ON(!folio_test_locked(folio));
 	BUG_ON(folio_test_writeback(folio));
 
@@ -186,44 +185,53 @@ mext_page_mkuptodate(struct folio *folio, unsigned from, unsigned to)
 	if (!head)
 		head = create_empty_buffers(folio, blocksize, 0);
 
-	block = (sector_t)folio->index << (PAGE_SHIFT - inode->i_blkbits);
-	for (bh = head, block_start = 0; bh != head || !block_start;
-	     block++, block_start = block_end, bh = bh->b_this_page) {
+	block = folio_pos(folio) >> inode->i_blkbits;
+	block_end = 0;
+	bh = head;
+	do {
+		block_start = block_end;
 		block_end = block_start + blocksize;
 		if (block_end <= from || block_start >= to) {
 			if (!buffer_uptodate(bh))
-				partial = 1;
+				partial = true;
 			continue;
 		}
 		if (buffer_uptodate(bh))
 			continue;
 		if (!buffer_mapped(bh)) {
-			err = ext4_get_block(inode, block, bh, 0);
-			if (err) {
-				folio_set_error(folio);
+			int err = ext4_get_block(inode, block, bh, 0);
+			if (err)
 				return err;
-			}
 			if (!buffer_mapped(bh)) {
 				folio_zero_range(folio, block_start, blocksize);
 				set_buffer_uptodate(bh);
 				continue;
 			}
 		}
-		BUG_ON(nr >= MAX_BUF_PER_PAGE);
-		arr[nr++] = bh;
-	}
+		lock_buffer(bh);
+		if (buffer_uptodate(bh)) {
+			unlock_buffer(bh);
+			continue;
+		}
+		ext4_read_bh_nowait(bh, 0, NULL, false);
+		nr++;
+	} while (block++, (bh = bh->b_this_page) != head);
+
 	/* No io required */
 	if (!nr)
 		goto out;
 
-	for (i = 0; i < nr; i++) {
-		bh = arr[i];
-		if (!bh_uptodate_or_lock(bh)) {
-			err = ext4_read_bh(bh, 0, NULL);
-			if (err)
-				return err;
-		}
-	}
+	bh = head;
+	do {
+		if (bh_offset(bh) + blocksize <= from)
+			continue;
+		if (bh_offset(bh) > to)
+			break;
+		wait_on_buffer(bh);
+		if (buffer_uptodate(bh))
+			continue;
+		return -EIO;
+	} while ((bh = bh->b_this_page) != head);
 out:
 	if (!partial)
 		folio_mark_uptodate(folio);
@@ -261,7 +269,7 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
 	unsigned int tmp_data_size, data_size, replaced_size;
 	int i, err2, jblocks, retries = 0;
 	int replaced_count = 0;
-	int from = data_offset_in_page << orig_inode->i_blkbits;
+	int from;
 	int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;
 	struct super_block *sb = orig_inode->i_sb;
 	struct buffer_head *bh = NULL;
@@ -315,11 +323,6 @@ again:
 	 * hold page's lock, if it is still the case data copy is not
 	 * necessary, just swap data blocks between orig and donor.
 	 */
-
-	VM_BUG_ON_FOLIO(folio_test_large(folio[0]), folio[0]);
-	VM_BUG_ON_FOLIO(folio_test_large(folio[1]), folio[1]);
-	VM_BUG_ON_FOLIO(folio_nr_pages(folio[0]) != folio_nr_pages(folio[1]), folio[1]);
-
 	if (unwritten) {
 		ext4_double_down_write_data_sem(orig_inode, donor_inode);
 		/* If any of extents in range became initialized we have to
@@ -352,6 +355,8 @@ again:
 		goto unlock_folios;
 	}
 data_copy:
+	from = offset_in_folio(folio[0],
+			       orig_blk_offset << orig_inode->i_blkbits);
 	*err = mext_page_mkuptodate(folio[0], from, from + replaced_size);
 	if (*err)
 		goto unlock_folios;
@@ -382,7 +387,7 @@ data_copy:
 	if (!bh)
 		bh = create_empty_buffers(folio[0],
 				1 << orig_inode->i_blkbits, 0);
-	for (i = 0; i < data_offset_in_page; i++)
+	for (i = 0; i < from >> orig_inode->i_blkbits; i++)
 		bh = bh->b_this_page;
 	for (i = 0; i < block_len_in_page; i++) {
 		*err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);
@@ -391,7 +396,7 @@ data_copy:
 		bh = bh->b_this_page;
 	}
 
-	block_commit_write(&folio[0]->page, from, from + replaced_size);
+	block_commit_write(folio[0], from, from + replaced_size);
 
 	/* Even in case of data=writeback it is reasonable to pin
 	 * inode to transaction, to prevent unexpected data loss */
@@ -626,9 +631,11 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
 		int offset_in_page;
 		int unwritten, cur_len;
 
-		ret = get_ext_path(orig_inode, o_start, &path);
-		if (ret)
+		path = get_ext_path(orig_inode, o_start, path);
+		if (IS_ERR(path)) {
+			ret = PTR_ERR(path);
 			goto out;
+		}
 		ex = path[path->p_depth].p_ext;
 		cur_blk = le32_to_cpu(ex->ee_block);
 		cur_len = ext4_ext_get_actual_len(ex);