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, 25 insertions, 25 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 8c417864c66a..0f124e8de1d4 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -590,7 +590,7 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
 	struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
 
-	down_write(&io->io_rwsem);
+	f2fs_down_write(&io->io_rwsem);
 
 	/* change META to META_FLUSH in the checkpoint procedure */
 	if (type >= META_FLUSH) {
@@ -601,7 +601,7 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
 			io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
 	}
 	__submit_merged_bio(io);
-	up_write(&io->io_rwsem);
+	f2fs_up_write(&io->io_rwsem);
 }
 
 static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
@@ -616,9 +616,9 @@ static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
 			enum page_type btype = PAGE_TYPE_OF_BIO(type);
 			struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
 
-			down_read(&io->io_rwsem);
+			f2fs_down_read(&io->io_rwsem);
 			ret = __has_merged_page(io->bio, inode, page, ino);
-			up_read(&io->io_rwsem);
+			f2fs_up_read(&io->io_rwsem);
 		}
 		if (ret)
 			__f2fs_submit_merged_write(sbi, type, temp);
@@ -742,9 +742,9 @@ static void add_bio_entry(struct f2fs_sb_info *sbi, struct bio *bio,
 	if (bio_add_page(bio, page, PAGE_SIZE, 0) != PAGE_SIZE)
 		f2fs_bug_on(sbi, 1);
 
-	down_write(&io->bio_list_lock);
+	f2fs_down_write(&io->bio_list_lock);
 	list_add_tail(&be->list, &io->bio_list);
-	up_write(&io->bio_list_lock);
+	f2fs_up_write(&io->bio_list_lock);
 }
 
 static void del_bio_entry(struct bio_entry *be)
@@ -766,7 +766,7 @@ static int add_ipu_page(struct f2fs_io_info *fio, struct bio **bio,
 		struct list_head *head = &io->bio_list;
 		struct bio_entry *be;
 
-		down_write(&io->bio_list_lock);
+		f2fs_down_write(&io->bio_list_lock);
 		list_for_each_entry(be, head, list) {
 			if (be->bio != *bio)
 				continue;
@@ -790,7 +790,7 @@ static int add_ipu_page(struct f2fs_io_info *fio, struct bio **bio,
 			__submit_bio(sbi, *bio, DATA);
 			break;
 		}
-		up_write(&io->bio_list_lock);
+		f2fs_up_write(&io->bio_list_lock);
 	}
 
 	if (ret) {
@@ -816,7 +816,7 @@ void f2fs_submit_merged_ipu_write(struct f2fs_sb_info *sbi,
 		if (list_empty(head))
 			continue;
 
-		down_read(&io->bio_list_lock);
+		f2fs_down_read(&io->bio_list_lock);
 		list_for_each_entry(be, head, list) {
 			if (target)
 				found = (target == be->bio);
@@ -826,14 +826,14 @@ void f2fs_submit_merged_ipu_write(struct f2fs_sb_info *sbi,
 			if (found)
 				break;
 		}
-		up_read(&io->bio_list_lock);
+		f2fs_up_read(&io->bio_list_lock);
 
 		if (!found)
 			continue;
 
 		found = false;
 
-		down_write(&io->bio_list_lock);
+		f2fs_down_write(&io->bio_list_lock);
 		list_for_each_entry(be, head, list) {
 			if (target)
 				found = (target == be->bio);
@@ -846,7 +846,7 @@ void f2fs_submit_merged_ipu_write(struct f2fs_sb_info *sbi,
 				break;
 			}
 		}
-		up_write(&io->bio_list_lock);
+		f2fs_up_write(&io->bio_list_lock);
 	}
 
 	if (found)
@@ -906,7 +906,7 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 
 	f2fs_bug_on(sbi, is_read_io(fio->op));
 
-	down_write(&io->io_rwsem);
+	f2fs_down_write(&io->io_rwsem);
 next:
 	if (fio->in_list) {
 		spin_lock(&io->io_lock);
@@ -973,7 +973,7 @@ out:
 	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
 				!f2fs_is_checkpoint_ready(sbi))
 		__submit_merged_bio(io);
-	up_write(&io->io_rwsem);
+	f2fs_up_write(&io->io_rwsem);
 }
 
 static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
@@ -1383,9 +1383,9 @@ void f2fs_do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock)
 {
 	if (flag == F2FS_GET_BLOCK_PRE_AIO) {
 		if (lock)
-			down_read(&sbi->node_change);
+			f2fs_down_read(&sbi->node_change);
 		else
-			up_read(&sbi->node_change);
+			f2fs_up_read(&sbi->node_change);
 	} else {
 		if (lock)
 			f2fs_lock_op(sbi);
@@ -2749,13 +2749,13 @@ write:
 		 * the below discard race condition.
 		 */
 		if (IS_NOQUOTA(inode))
-			down_read(&sbi->node_write);
+			f2fs_down_read(&sbi->node_write);
 
 		fio.need_lock = LOCK_DONE;
 		err = f2fs_do_write_data_page(&fio);
 
 		if (IS_NOQUOTA(inode))
-			up_read(&sbi->node_write);
+			f2fs_up_read(&sbi->node_write);
 
 		goto done;
 	}
@@ -3213,14 +3213,14 @@ void f2fs_write_failed(struct inode *inode, loff_t to)
 
 	/* In the fs-verity case, f2fs_end_enable_verity() does the truncate */
 	if (to > i_size && !f2fs_verity_in_progress(inode)) {
-		down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+		f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 		filemap_invalidate_lock(inode->i_mapping);
 
 		truncate_pagecache(inode, i_size);
 		f2fs_truncate_blocks(inode, i_size, true);
 
 		filemap_invalidate_unlock(inode->i_mapping);
-		up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+		f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 	}
 }
 
@@ -3721,13 +3721,13 @@ static int f2fs_migrate_blocks(struct inode *inode, block_t start_blk,
 	unsigned int end_sec = secidx + blkcnt / blk_per_sec;
 	int ret = 0;
 
-	down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+	f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 	filemap_invalidate_lock(inode->i_mapping);
 
 	set_inode_flag(inode, FI_ALIGNED_WRITE);
 
 	for (; secidx < end_sec; secidx++) {
-		down_write(&sbi->pin_sem);
+		f2fs_down_write(&sbi->pin_sem);
 
 		f2fs_lock_op(sbi);
 		f2fs_allocate_new_section(sbi, CURSEG_COLD_DATA_PINNED, false);
@@ -3741,7 +3741,7 @@ static int f2fs_migrate_blocks(struct inode *inode, block_t start_blk,
 
 			page = f2fs_get_lock_data_page(inode, blkidx, true);
 			if (IS_ERR(page)) {
-				up_write(&sbi->pin_sem);
+				f2fs_up_write(&sbi->pin_sem);
 				ret = PTR_ERR(page);
 				goto done;
 			}
@@ -3754,7 +3754,7 @@ static int f2fs_migrate_blocks(struct inode *inode, block_t start_blk,
 
 		ret = filemap_fdatawrite(inode->i_mapping);
 
-		up_write(&sbi->pin_sem);
+		f2fs_up_write(&sbi->pin_sem);
 
 		if (ret)
 			break;
@@ -3765,7 +3765,7 @@ done:
 	clear_inode_flag(inode, FI_ALIGNED_WRITE);
 
 	filemap_invalidate_unlock(inode->i_mapping);
-	up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
+	f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 
 	return ret;
 }