f2fs: avoid f2fs_lock_op in f2fs_write_begin
If f2fs_write_begin is to update data, we can bypass calling f2fs_lock_op() in
order to avoid the checkpoint latency in the write syscall.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d4839fc..f2a023e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1418,10 +1418,16 @@
pgoff_t index = page->index;
struct dnode_of_data dn;
struct page *ipage;
+ bool locked = false;
+ struct extent_info ei;
int err = 0;
- f2fs_lock_op(sbi);
-
+ if (f2fs_has_inline_data(inode) ||
+ (pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
+ f2fs_lock_op(sbi);
+ locked = true;
+ }
+restart:
/* check inline_data */
ipage = get_node_page(sbi, inode->i_ino);
if (IS_ERR(ipage)) {
@@ -1436,22 +1442,42 @@
read_inline_data(page, ipage);
set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
sync_inode_page(&dn);
- goto done;
} else {
err = f2fs_convert_inline_page(&dn, page);
if (err)
- goto err_out;
+ goto out;
+ if (dn.data_blkaddr == NULL_ADDR)
+ err = f2fs_get_block(&dn, index);
+ }
+ } else if (locked) {
+ err = f2fs_get_block(&dn, index);
+ } else {
+ if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+ dn.data_blkaddr = ei.blk + index - ei.fofs;
+ } else {
+ bool restart = false;
+
+ /* hole case */
+ err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+ if (err || (!err && dn.data_blkaddr == NULL_ADDR))
+ restart = true;
+ if (restart) {
+ f2fs_put_dnode(&dn);
+ f2fs_lock_op(sbi);
+ locked = true;
+ goto restart;
+ }
}
}
- err = f2fs_get_block(&dn, index);
-done:
+
/* convert_inline_page can make node_changed */
*blk_addr = dn.data_blkaddr;
*node_changed = dn.node_changed;
-err_out:
+out:
f2fs_put_dnode(&dn);
unlock_out:
- f2fs_unlock_op(sbi);
+ if (locked)
+ f2fs_unlock_op(sbi);
return err;
}
