From 973163fc0ce07761eae671e895dc6747a3410fe7 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 18 Sep 2015 16:51:51 +0800 Subject: [PATCH] f2fs: reorganize f2fs_map_blocks In this patch, we try to reorganize f2fs_map_blocks to make block mapping flow more clear by using following structure: /* check status of mapping */ if (unmapped) { /* blkaddr == NULL_ADDR || blkaddr == NEW_ADDR */ if (create) { /* write path, handle dio write case here */ alloc_and_map; } else { /* * handle read cases from all call paths: * 1. generic read; * 2. dio read; * 3. fiemap; * 4. bmap */ } } /* map buffer_header */ Besides, this patch handles the missing case correctly for dio write: When we fail in __allocate_data_blocks, then in f2fs_map_blocks, we will not allocate blocks correctly for preallocated blocks, but returning with an unmapped buffer head, which will result in failure of dio write. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 84 ++++++++++++++++++++++++++------------------------ 1 file changed, 44 insertions(+), 40 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 681373e1da92..883b6499841f 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -596,40 +596,36 @@ static int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, err = 0; goto unlock_out; } - if (dn.data_blkaddr == NEW_ADDR) { - if (flag == F2FS_GET_BLOCK_BMAP) { - err = -ENOENT; - goto put_out; - } else if (flag == F2FS_GET_BLOCK_READ || - flag == F2FS_GET_BLOCK_DIO) { - goto put_out; + + if (dn.data_blkaddr == NEW_ADDR || dn.data_blkaddr == NULL_ADDR) { + if (create) { + err = __allocate_data_block(&dn); + if (err) + goto put_out; + allocated = true; + map->m_flags = F2FS_MAP_NEW; + } else { + if (flag != F2FS_GET_BLOCK_FIEMAP || + dn.data_blkaddr != NEW_ADDR) { + if (flag == F2FS_GET_BLOCK_BMAP) + err = -ENOENT; + goto put_out; + } + + /* + * preallocated unwritten block should be mapped + * for fiemap. + */ + if (dn.data_blkaddr == NEW_ADDR) + map->m_flags = F2FS_MAP_UNWRITTEN; } - /* - * if it is in fiemap call path (flag = F2FS_GET_BLOCK_FIEMAP), - * mark it as mapped and unwritten block. - */ } - if (dn.data_blkaddr != NULL_ADDR) { - map->m_flags = F2FS_MAP_MAPPED; - map->m_pblk = dn.data_blkaddr; - if (dn.data_blkaddr == NEW_ADDR) - map->m_flags |= F2FS_MAP_UNWRITTEN; - } else if (create) { - err = __allocate_data_block(&dn); - if (err) - goto put_out; - allocated = true; - map->m_flags = F2FS_MAP_NEW | F2FS_MAP_MAPPED; - map->m_pblk = dn.data_blkaddr; - } else { - if (flag == F2FS_GET_BLOCK_BMAP) - err = -ENOENT; - goto put_out; - } + map->m_flags |= F2FS_MAP_MAPPED; + map->m_pblk = dn.data_blkaddr; + map->m_len = 1; end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode)); - map->m_len = 1; dn.ofs_in_node++; pgofs++; @@ -648,23 +644,31 @@ get_next: goto unlock_out; } - if (dn.data_blkaddr == NEW_ADDR && - flag != F2FS_GET_BLOCK_FIEMAP) - goto put_out; - end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode)); } if (maxblocks > map->m_len) { block_t blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node); - if (blkaddr == NULL_ADDR && create) { - err = __allocate_data_block(&dn); - if (err) - goto sync_out; - allocated = true; - map->m_flags |= F2FS_MAP_NEW; - blkaddr = dn.data_blkaddr; + + if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) { + if (create) { + 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)) || -- 2.20.1