f2fs: do in batches truncation in truncate_hole

truncate_data_blocks_range can do in batches truncation which makes all
changes in dnode page content, dnode page status, extent cache, block
count updating together.

But previously, truncate_hole() always truncates one block in dnode page
at a time by invoking truncate_data_blocks_range(,1), which make thing
slow.

This patch changes truncate_hole() to do in batches truncation for all
target blocks in one direct node inside truncate_data_blocks_range, which
can make our punch hole operation in ->fallocate more efficent.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 27a789c0d3c23cbe6ac807016109f550c0be4879..6702157801a669327ece2d791154966877f80041 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -739,23 +739,31 @@ static int fill_zero(struct inode *inode, pgoff_t index,
 
 int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
 {
-       pgoff_t index;
        int err;
 
-       for (index = pg_start; index < pg_end; index++) {
+       while (pg_start < pg_end) {
                struct dnode_of_data dn;
+               pgoff_t end_offset, count;
 
                set_new_dnode(&dn, inode, NULL, NULL, 0);
-               err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+               err = get_dnode_of_data(&dn, pg_start, LOOKUP_NODE);
                if (err) {
-                       if (err == -ENOENT)
+                       if (err == -ENOENT) {
+                               pg_start++;
                                continue;
+                       }
                        return err;
                }
 
-               if (dn.data_blkaddr != NULL_ADDR)
-                       truncate_data_blocks_range(&dn, 1);
+               end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+               count = min(end_offset - dn.ofs_in_node, pg_end - pg_start);
+
+               f2fs_bug_on(F2FS_I_SB(inode), count == 0 || count > end_offset);
+
+               truncate_data_blocks_range(&dn, count);
                f2fs_put_dnode(&dn);
+
+               pg_start += count;
        }
        return 0;
 }