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@xxxxxxxxxx>
---
fs/f2fs/data.c | 7 +++++--
fs/f2fs/f2fs.h | 3 ++-
fs/f2fs/segment.c | 27 +++++++++++++++++++--------
3 files changed, 26 insertions(+), 11 deletions(-)
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 @@ static int __allocate_data_block(struct dnode_of_data *dn)
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 @@ static int __allocate_data_block(struct dnode_of_data *dn)
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);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 37e935a..ba30218 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -406,7 +406,8 @@ enum {
CURSEG_HOT_NODE, /* direct node blocks of directory files */
CURSEG_WARM_NODE, /* direct node blocks of normal files */
CURSEG_COLD_NODE, /* indirect node blocks */
- NO_CHECK_TYPE
+ NO_CHECK_TYPE,
+ CURSEG_DIRECT_IO, /* to use for the direct IO path */
};
struct flush_cmd {
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 8144a30..31c4e57 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1024,18 +1024,22 @@ static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
stat_inc_seg_type(sbi, curseg);
}
+static void __allocate_new_segments(struct f2fs_sb_info *sbi, int type)
+{
+ struct curseg_info *curseg = CURSEG_I(sbi, type);
+ unsigned int old_segno;
+
+ old_segno = curseg->segno;
+ SIT_I(sbi)->s_ops->allocate_segment(sbi, type, true);
+ locate_dirty_segment(sbi, old_segno);
+}
+
void allocate_new_segments(struct f2fs_sb_info *sbi)
{
- struct curseg_info *curseg;
- unsigned int old_curseg;
int i;
- for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
- curseg = CURSEG_I(sbi, i);
- old_curseg = curseg->segno;
- SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
- locate_dirty_segment(sbi, old_curseg);
- }
+ for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++)
+ __allocate_new_segments(sbi, i);
}
static const struct segment_allocation default_salloc_ops = {
@@ -1148,11 +1152,18 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
{
struct sit_info *sit_i = SIT_I(sbi);
struct curseg_info *curseg;
+ bool direct_io = (type == CURSEG_DIRECT_IO);
+
+ type = direct_io ? CURSEG_WARM_DATA : type;
curseg = CURSEG_I(sbi, type);
mutex_lock(&curseg->curseg_mutex);
+ /* direct_io'ed data is aligned to the segment for better performance */
+ if (direct_io && curseg->next_blkoff)
+ __allocate_new_segments(sbi, type);
+
*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
/*
--
2.1.1
--
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