f2fs: move f2fs to use reader-unfair rwsems

f2fs rw_semaphores work better if writers can starve readers,
especially for the checkpoint thread, because writers are strictly
more important than reader threads. This prevents significant priority
inversion between low-priority readers that blocked while trying to
acquire the read lock and a second acquisition of the write lock that
might be blocking high priority work.

Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 22 insertions, 22 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 1dabc8244083..216538b57331 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -471,7 +471,7 @@ int f2fs_commit_inmem_pages(struct inode *inode)
 
 	f2fs_balance_fs(sbi, true);
 
-	down_write(&fi->i_gc_rwsem[WRITE]);
+	f2fs_down_write(&fi->i_gc_rwsem[WRITE]);
 
 	f2fs_lock_op(sbi);
 	set_inode_flag(inode, FI_ATOMIC_COMMIT);
@@ -483,7 +483,7 @@ int f2fs_commit_inmem_pages(struct inode *inode)
 	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
 
 	f2fs_unlock_op(sbi);
-	up_write(&fi->i_gc_rwsem[WRITE]);
+	f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
 
 	return err;
 }
@@ -521,7 +521,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
 			io_schedule();
 			finish_wait(&sbi->gc_thread->fggc_wq, &wait);
 		} else {
-			down_write(&sbi->gc_lock);
+			f2fs_down_write(&sbi->gc_lock);
 			f2fs_gc(sbi, false, false, false, NULL_SEGNO);
 		}
 	}
@@ -529,7 +529,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
 
 static inline bool excess_dirty_threshold(struct f2fs_sb_info *sbi)
 {
-	int factor = rwsem_is_locked(&sbi->cp_rwsem) ? 3 : 2;
+	int factor = f2fs_rwsem_is_locked(&sbi->cp_rwsem) ? 3 : 2;
 	unsigned int dents = get_pages(sbi, F2FS_DIRTY_DENTS);
 	unsigned int qdata = get_pages(sbi, F2FS_DIRTY_QDATA);
 	unsigned int nodes = get_pages(sbi, F2FS_DIRTY_NODES);
@@ -570,7 +570,7 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi, bool from_bg)
 
 	/* there is background inflight IO or foreground operation recently */
 	if (is_inflight_io(sbi, REQ_TIME) ||
-		(!f2fs_time_over(sbi, REQ_TIME) && rwsem_is_locked(&sbi->cp_rwsem)))
+		(!f2fs_time_over(sbi, REQ_TIME) && f2fs_rwsem_is_locked(&sbi->cp_rwsem)))
 		return;
 
 	/* exceed periodical checkpoint timeout threshold */
@@ -2821,7 +2821,7 @@ static void __f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
 	if (!sbi->am.atgc_enabled)
 		return;
 
-	down_read(&SM_I(sbi)->curseg_lock);
+	f2fs_down_read(&SM_I(sbi)->curseg_lock);
 
 	mutex_lock(&curseg->curseg_mutex);
 	down_write(&SIT_I(sbi)->sentry_lock);
@@ -2831,7 +2831,7 @@ static void __f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
 	up_write(&SIT_I(sbi)->sentry_lock);
 	mutex_unlock(&curseg->curseg_mutex);
 
-	up_read(&SM_I(sbi)->curseg_lock);
+	f2fs_up_read(&SM_I(sbi)->curseg_lock);
 
 }
 void f2fs_init_inmem_curseg(struct f2fs_sb_info *sbi)
@@ -2982,7 +2982,7 @@ void f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int type,
 	struct curseg_info *curseg = CURSEG_I(sbi, type);
 	unsigned int segno;
 
-	down_read(&SM_I(sbi)->curseg_lock);
+	f2fs_down_read(&SM_I(sbi)->curseg_lock);
 	mutex_lock(&curseg->curseg_mutex);
 	down_write(&SIT_I(sbi)->sentry_lock);
 
@@ -3006,7 +3006,7 @@ unlock:
 			    type, segno, curseg->segno);
 
 	mutex_unlock(&curseg->curseg_mutex);
-	up_read(&SM_I(sbi)->curseg_lock);
+	f2fs_up_read(&SM_I(sbi)->curseg_lock);
 }
 
 static void __allocate_new_segment(struct f2fs_sb_info *sbi, int type,
@@ -3038,23 +3038,23 @@ static void __allocate_new_section(struct f2fs_sb_info *sbi,
 
 void f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type, bool force)
 {
-	down_read(&SM_I(sbi)->curseg_lock);
+	f2fs_down_read(&SM_I(sbi)->curseg_lock);
 	down_write(&SIT_I(sbi)->sentry_lock);
 	__allocate_new_section(sbi, type, force);
 	up_write(&SIT_I(sbi)->sentry_lock);
-	up_read(&SM_I(sbi)->curseg_lock);
+	f2fs_up_read(&SM_I(sbi)->curseg_lock);
 }
 
 void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi)
 {
 	int i;
 
-	down_read(&SM_I(sbi)->curseg_lock);
+	f2fs_down_read(&SM_I(sbi)->curseg_lock);
 	down_write(&SIT_I(sbi)->sentry_lock);
 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++)
 		__allocate_new_segment(sbi, i, false, false);
 	up_write(&SIT_I(sbi)->sentry_lock);
-	up_read(&SM_I(sbi)->curseg_lock);
+	f2fs_up_read(&SM_I(sbi)->curseg_lock);
 }
 
 static const struct segment_allocation default_salloc_ops = {
@@ -3192,9 +3192,9 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
 	if (sbi->discard_blks == 0)
 		goto out;
 
-	down_write(&sbi->gc_lock);
+	f2fs_down_write(&sbi->gc_lock);
 	err = f2fs_write_checkpoint(sbi, &cpc);
-	up_write(&sbi->gc_lock);
+	f2fs_up_write(&sbi->gc_lock);
 	if (err)
 		goto out;
 
@@ -3431,7 +3431,7 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	bool from_gc = (type == CURSEG_ALL_DATA_ATGC);
 	struct seg_entry *se = NULL;
 
-	down_read(&SM_I(sbi)->curseg_lock);
+	f2fs_down_read(&SM_I(sbi)->curseg_lock);
 
 	mutex_lock(&curseg->curseg_mutex);
 	down_write(&sit_i->sentry_lock);
@@ -3514,7 +3514,7 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 
 	mutex_unlock(&curseg->curseg_mutex);
 
-	up_read(&SM_I(sbi)->curseg_lock);
+	f2fs_up_read(&SM_I(sbi)->curseg_lock);
 }
 
 void f2fs_update_device_state(struct f2fs_sb_info *sbi, nid_t ino,
@@ -3550,7 +3550,7 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 	bool keep_order = (f2fs_lfs_mode(fio->sbi) && type == CURSEG_COLD_DATA);
 
 	if (keep_order)
-		down_read(&fio->sbi->io_order_lock);
+		f2fs_down_read(&fio->sbi->io_order_lock);
 reallocate:
 	f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
 			&fio->new_blkaddr, sum, type, fio);
@@ -3570,7 +3570,7 @@ reallocate:
 	f2fs_update_device_state(fio->sbi, fio->ino, fio->new_blkaddr, 1);
 
 	if (keep_order)
-		up_read(&fio->sbi->io_order_lock);
+		f2fs_up_read(&fio->sbi->io_order_lock);
 }
 
 void f2fs_do_write_meta_page(struct f2fs_sb_info *sbi, struct page *page,
@@ -3705,7 +3705,7 @@ void f2fs_do_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 	se = get_seg_entry(sbi, segno);
 	type = se->type;
 
-	down_write(&SM_I(sbi)->curseg_lock);
+	f2fs_down_write(&SM_I(sbi)->curseg_lock);
 
 	if (!recover_curseg) {
 		/* for recovery flow */
@@ -3774,7 +3774,7 @@ void f2fs_do_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 
 	up_write(&sit_i->sentry_lock);
 	mutex_unlock(&curseg->curseg_mutex);
-	up_write(&SM_I(sbi)->curseg_lock);
+	f2fs_up_write(&SM_I(sbi)->curseg_lock);
 }
 
 void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
@@ -5258,7 +5258,7 @@ int f2fs_build_segment_manager(struct f2fs_sb_info *sbi)
 
 	INIT_LIST_HEAD(&sm_info->sit_entry_set);
 
-	init_rwsem(&sm_info->curseg_lock);
+	init_f2fs_rwsem(&sm_info->curseg_lock);
 
 	if (!f2fs_readonly(sbi->sb)) {
 		err = f2fs_create_flush_cmd_control(sbi);