f2fs: align direct_io'ed data to section
This patch aligns the start block address of a file for direct io to the f2fs's
section size.
Some flash devices manage an over 4KB-sized page as a write unit, and if the
direct_io'ed data are written but not aligned to that unit, the performance can
be degraded due to the partial page copies.
Thus, since f2fs has a section that is well aligned to FTL units, we can align
the block address to the section size so that f2fs avoids this misalignment.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 3e0f5f3..b48b355 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -564,6 +564,7 @@
struct f2fs_inode_info *fi = F2FS_I(dn->inode);
struct f2fs_summary sum;
struct node_info ni;
+ int seg = CURSEG_WARM_DATA;
pgoff_t fofs;
if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
@@ -574,8 +575,10 @@
get_node_info(sbi, dn->nid, &ni);
set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
- allocate_data_block(sbi, NULL, NULL_ADDR, &dn->data_blkaddr, &sum,
- CURSEG_WARM_DATA);
+ if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
+ seg = CURSEG_DIRECT_IO;
+
+ allocate_data_block(sbi, NULL, NULL_ADDR, &dn->data_blkaddr, &sum, seg);
/* direct IO doesn't use extent cache to maximize the performance */
__set_data_blkaddr(dn);