Re: [PATCH v2] f2fs: avoid cpu lockup

From: Jaegeuk Kim
Date: Sat Jul 15 2017 - 21:04:46 EST


Before retrying to flush data or dentry pages, we need to release cpu in order
to prevent watchdog.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
Change log from v1:
- timeout more specifically

fs/f2fs/checkpoint.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 56bbf592e487..5b876f6d3f6b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -879,6 +879,7 @@ int sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type)
struct inode *inode;
struct f2fs_inode_info *fi;
bool is_dir = (type == DIR_INODE);
+ unsigned long ino = 0;

trace_f2fs_sync_dirty_inodes_enter(sbi->sb, is_dir,
get_pages(sbi, is_dir ?
@@ -901,8 +902,17 @@ int sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type)
inode = igrab(&fi->vfs_inode);
spin_unlock(&sbi->inode_lock[type]);
if (inode) {
+ unsigned long cur_ino = inode->i_ino;
+
filemap_fdatawrite(inode->i_mapping);
iput(inode);
+ /* We need to give cpu to another writers. */
+ if (ino == cur_ino) {
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
+ cond_resched();
+ } else {
+ ino = cur_ino;
+ }
} else {
/*
* We should submit bio, since it exists several
--
2.13.0.rc1.294.g07d810a77f-goog