f2fs: reduce competition among node page writes
We do not need to block on ->node_write among different node page writers e.g.
fsync/flush, unless we have a node page writer from write_checkpoint.
So it's better use rw_semaphore instead of mutex type for ->node_write to
promote performance.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index cea20b8..6aeed5b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -762,10 +762,10 @@
* until finishing nat/sit flush.
*/
retry_flush_nodes:
- mutex_lock(&sbi->node_write);
+ down_write(&sbi->node_write);
if (get_pages(sbi, F2FS_DIRTY_NODES)) {
- mutex_unlock(&sbi->node_write);
+ up_write(&sbi->node_write);
sync_node_pages(sbi, 0, &wbc);
goto retry_flush_nodes;
}
@@ -774,7 +774,7 @@
static void unblock_operations(struct f2fs_sb_info *sbi)
{
- mutex_unlock(&sbi->node_write);
+ up_write(&sbi->node_write);
f2fs_unlock_all(sbi);
}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 80c7869..9942567 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -452,7 +452,7 @@
struct inode *meta_inode; /* cache meta blocks */
struct mutex cp_mutex; /* checkpoint procedure lock */
struct rw_semaphore cp_rwsem; /* blocking FS operations */
- struct mutex node_write; /* locking node writes */
+ struct rw_semaphore node_write; /* locking node writes */
struct mutex writepages; /* mutex for writepages() */
bool por_doing; /* recovery is doing or not */
wait_queue_head_t cp_wait;
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index a90f51d..7b5b5de 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1231,12 +1231,12 @@
if (wbc->for_reclaim)
goto redirty_out;
- mutex_lock(&sbi->node_write);
+ down_read(&sbi->node_write);
set_page_writeback(page);
write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
dec_page_count(sbi, F2FS_DIRTY_NODES);
- mutex_unlock(&sbi->node_write);
+ up_read(&sbi->node_write);
unlock_page(page);
return 0;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f253e22..657582f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -953,7 +953,7 @@
mutex_init(&sbi->gc_mutex);
mutex_init(&sbi->writepages);
mutex_init(&sbi->cp_mutex);
- mutex_init(&sbi->node_write);
+ init_rwsem(&sbi->node_write);
sbi->por_doing = false;
spin_lock_init(&sbi->stat_lock);