[PATCH 2/6] f2fs: declare nested quota_sem and remove unnecessary sems

[Jaegeuk Kim]

1.
f2fs_quota_sync
 -> down_read(&sbi->quota_sem)
 -> dquot_writeback_dquots
  -> f2fs_dquot_commit
   -> down_read(&sbi->quota_sem)

2.
f2fs_quota_sync
 -> down_read(&sbi->quota_sem)
  -> f2fs_write_data_pages
   -> f2fs_write_single_data_page
    -> down_write(&F2FS_I(inode)->i_sem)

f2fs_mkdir
 -> f2fs_do_add_link
   -> down_write(&F2FS_I(inode)->i_sem)
   -> f2fs_init_inode_metadata
    -> f2fs_new_node_page
     -> dquot_alloc_inode
      -> f2fs_dquot_mark_dquot_dirty
       -> down_read(&sbi->quota_sem)

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
 fs/f2fs/super.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 5111e1ffe58a..15888ca02e7f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2156,39 +2156,30 @@ static void f2fs_truncate_quota_inode_pages(struct super_block *sb)
 static int f2fs_dquot_commit(struct dquot *dquot)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb);
-	int ret;
+	int ret = dquot_commit(dquot);
 
-	down_read(&sbi->quota_sem);
-	ret = dquot_commit(dquot);
 	if (ret < 0)
 		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
-	up_read(&sbi->quota_sem);
 	return ret;
 }
 
 static int f2fs_dquot_acquire(struct dquot *dquot)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb);
-	int ret;
+	int ret = dquot_acquire(dquot);
 
-	down_read(&sbi->quota_sem);
-	ret = dquot_acquire(dquot);
 	if (ret < 0)
 		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
-	up_read(&sbi->quota_sem);
 	return ret;
 }
 
 static int f2fs_dquot_release(struct dquot *dquot)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb);
-	int ret;
+	int ret = dquot_release(dquot);
 
-	down_read(&sbi->quota_sem);
-	ret = dquot_release(dquot);
 	if (ret < 0)
 		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
-	up_read(&sbi->quota_sem);
 	return ret;
 }
 
@@ -2198,7 +2189,7 @@ static int f2fs_dquot_mark_dquot_dirty(struct dquot *dquot)
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
 	int ret;
 
-	down_read(&sbi->quota_sem);
+	down_read_nested(&sbi->quota_sem, SINGLE_DEPTH_NESTING);
 	ret = dquot_mark_dquot_dirty(dquot);
 
 	/* if we are using journalled quota */
@@ -2212,13 +2203,10 @@ static int f2fs_dquot_mark_dquot_dirty(struct dquot *dquot)
 static int f2fs_dquot_commit_info(struct super_block *sb, int type)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
-	int ret;
+	int ret = dquot_commit_info(sb, type);
 
-	down_read(&sbi->quota_sem);
-	ret = dquot_commit_info(sb, type);
 	if (ret < 0)
 		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
-	up_read(&sbi->quota_sem);
 	return ret;
 }
 
-- 
2.19.0.605.g01d371f741-goog