[PATCH] f2fs: fix to avoid use SSR allocate when do defragment

[Zhiguo Niu]

SSR allocate mode will be used when doing file defragment
if ATGC is working at the same time, that is because
set_page_private_gcing may make CURSEG_ALL_DATA_ATGC segment
type got in f2fs_allocate_data_block when defragment page
is writeback, which may cause file fragmentation is worse.

A file with 2 fragmentations is changed as following after defragment:

----------------file info-------------------
sensorsdata :
--------------------------------------------
dev       [254:48]
ino       [0x    3029 : 12329]
mode      [0x    81b0 : 33200]
nlink     [0x       1 : 1]
uid       [0x    27e6 : 10214]
gid       [0x    27e6 : 10214]
size      [0x  242000 : 2367488]
blksize   [0x    1000 : 4096]
blocks    [0x    1210 : 4624]
--------------------------------------------

file_pos   start_blk     end_blk        blks
       0    11361121    11361207          87
  356352    11361215    11361216           2
  364544    11361218    11361218           1
  368640    11361220    11361221           2
  376832    11361224    11361225           2
  385024    11361227    11361238          12
  434176    11361240    11361252          13
  487424    11361254    11361254           1
  491520    11361271    11361279           9
  528384     3681794     3681795           2
  536576     3681797     3681797           1
  540672     3681799     3681799           1
  544768     3681803     3681803           1
  548864     3681805     3681805           1
  552960     3681807     3681807           1
  557056     3681809     3681809           1

A new FI flag FI_DEFRAG_IN_PROGRESS is introduced to avoid
this scenarios.

Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
---
 fs/f2fs/f2fs.h    | 1 +
 fs/f2fs/file.c    | 2 ++
 fs/f2fs/segment.c | 3 ++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 4044e67..9281c5e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -803,6 +803,7 @@ enum {
 	FI_COW_FILE,		/* indicate COW file */
 	FI_ATOMIC_COMMITTED,	/* indicate atomic commit completed except disk sync */
 	FI_ATOMIC_REPLACE,	/* indicate atomic replace */
+	FI_DEFRAG_IN_PROGRESS,	/* indicate file was defragmenting */
 	FI_MAX,			/* max flag, never be used */
 };
 
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 5c0b281..93d2767 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2717,6 +2717,7 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
 		goto out;
 	}
 
+	set_inode_flag(inode, FI_DEFRAG_IN_PROGRESS);
 	map.m_lblk = pg_start;
 	map.m_len = pg_end - pg_start;
 	total = 0;
@@ -2772,6 +2773,7 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
 clear_out:
 	clear_inode_flag(inode, FI_SKIP_WRITES);
 out:
+	clear_inode_flag(inode, FI_DEFRAG_IN_PROGRESS);
 	clear_inode_flag(inode, FI_OPU_WRITE);
 unlock_out:
 	inode_unlock(inode);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 7caf20a..dd6f8ac 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3482,7 +3482,8 @@ static int __get_segment_type_6(struct f2fs_io_info *fio)
 		if (page_private_gcing(fio->page)) {
 			if (fio->sbi->am.atgc_enabled &&
 				(fio->io_type == FS_DATA_IO) &&
-				(fio->sbi->gc_mode != GC_URGENT_HIGH))
+				(fio->sbi->gc_mode != GC_URGENT_HIGH) &&
+				!is_inode_flag_set(inode, FI_DEFRAG_IN_PROGRESS))
 				return CURSEG_ALL_DATA_ATGC;
 			else
 				return CURSEG_COLD_DATA;
-- 
1.9.1