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 <chao2...@samsung.com>
---
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 a82abe9..a737ca5 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -595,40 +595,36 @@ 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++;
@@ -647,23 +643,31 @@ 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)) ||
--
2.4.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
