f2fs: simplify f2fs_map_blocks

In f2fs_map_blocks, we use duplicated codes to handle first block mapping
and the following blocks mapping, it's unnecessary. This patch simplifies
f2fs_map_blocks to avoid using copied codes.

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

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 90b3a37..bd49a02 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -631,6 +631,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
                goto out;
        }
 
+next_dnode:
        if (create)
                f2fs_lock_op(sbi);
 
@@ -643,47 +644,57 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
                goto unlock_out;
        }
 
-       if (dn.data_blkaddr == NEW_ADDR || dn.data_blkaddr == NULL_ADDR) {
+       end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+
+next_block:
+       blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+
+       if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
                if (create) {
                        if (unlikely(f2fs_cp_error(sbi))) {
                                err = -EIO;
-                               goto put_out;
+                               goto sync_out;
                        }
                        err = __allocate_data_block(&dn);
                        if (err)
-                               goto put_out;
+                               goto sync_out;
                        allocated = true;
                        map->m_flags = F2FS_MAP_NEW;
+                       blkaddr = dn.data_blkaddr;
                } else {
                        if (flag != F2FS_GET_BLOCK_FIEMAP ||
-                                               dn.data_blkaddr != NEW_ADDR) {
+                                               blkaddr != NEW_ADDR) {
                                if (flag == F2FS_GET_BLOCK_BMAP)
                                        err = -ENOENT;
-                               goto put_out;
+                               goto sync_out;
                        }
-
-                       /*
-                        * preallocated unwritten block should be mapped
-                        * for fiemap.
-                        */
-                       if (dn.data_blkaddr == NEW_ADDR)
-                               map->m_flags = F2FS_MAP_UNWRITTEN;
                }
        }
 
-       map->m_flags |= F2FS_MAP_MAPPED;
-       map->m_pblk = dn.data_blkaddr;
-       map->m_len = 1;
+       if (map->m_len == 0) {
+               /* preallocated unwritten block should be mapped for fiemap. */
+               if (blkaddr == NEW_ADDR)
+                       map->m_flags |= F2FS_MAP_UNWRITTEN;
+               map->m_flags |= F2FS_MAP_MAPPED;
+
+               map->m_pblk = blkaddr;
+               map->m_len = 1;
+       } else if ((map->m_pblk != NEW_ADDR &&
+                       blkaddr == (map->m_pblk + ofs)) ||
+                       (map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR)) {
+               ofs++;
+               map->m_len++;
+       } else {
+               goto sync_out;
+       }
 
-       end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
        dn.ofs_in_node++;
        pgofs++;
 
-get_next:
-       if (map->m_len >= maxblocks)
-               goto sync_out;
+       if (map->m_len < maxblocks) {
+               if (dn.ofs_in_node < end_offset)
+                       goto next_block;
 
-       if (dn.ofs_in_node >= end_offset) {
                if (allocated)
                        sync_inode_page(&dn);
                f2fs_put_dnode(&dn);
@@ -691,62 +702,14 @@ get_next:
                if (create) {
                        f2fs_unlock_op(sbi);
                        f2fs_balance_fs(sbi, allocated);
-                       f2fs_lock_op(sbi);
                }
                allocated = false;
-
-               set_new_dnode(&dn, inode, NULL, NULL, 0);
-               err = get_dnode_of_data(&dn, pgofs, mode);
-               if (err) {
-                       if (err == -ENOENT)
-                               err = 0;
-                       goto unlock_out;
-               }
-
-               end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
-       }
-
-       blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
-
-       if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
-               if (create) {
-                       if (unlikely(f2fs_cp_error(sbi))) {
-                               err = -EIO;
-                               goto sync_out;
-                       }
-                       err = __allocate_data_block(&dn);
-                       if (err)
-                               goto sync_out;
-                       allocated = true;
-                       map->m_flags |= F2FS_MAP_NEW;
-                       blkaddr = dn.data_blkaddr;
-               } else {
-                       /*
-                        * we only merge preallocated unwritten blocks
-                        * for fiemap.
-                        */
-                       if (flag != F2FS_GET_BLOCK_FIEMAP ||
-                                       blkaddr != NEW_ADDR)
-                               goto sync_out;
-               }
-       }
-
-       /* Give more consecutive addresses for the readahead */
-       if ((map->m_pblk != NEW_ADDR &&
-                       blkaddr == (map->m_pblk + ofs)) ||
-                       (map->m_pblk == NEW_ADDR &&
-                       blkaddr == NEW_ADDR)) {
-               ofs++;
-               dn.ofs_in_node++;
-               pgofs++;
-               map->m_len++;
-               goto get_next;
+               goto next_dnode;
        }
 
 sync_out:
        if (allocated)
                sync_inode_page(&dn);
-put_out:
        f2fs_put_dnode(&dn);
 unlock_out:
        if (create) {