f2fs: stop gc/discard thread in prior during umount

This patch resolves kernel panic for xfstests/081, caused by recent f2fs_bug_on

 f2fs: add f2fs_bug_on in __remove_discard_cmd

For fixing, we will stop gc/discard thread in prior in ->kill_sb in order to
avoid referring and releasing race among them.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e15d55c..abf9eea 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2293,6 +2293,7 @@ void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free);
 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr);
 bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr);
 void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new);
+void stop_discard_thread(struct f2fs_sb_info *sbi);
 void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
 void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc);
 void release_discard_addrs(struct f2fs_sb_info *sbi);

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 7637033..6eaa98e 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1065,6 +1065,18 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
                __wait_one_discard_bio(sbi, dc);
 }
 
+void stop_discard_thread(struct f2fs_sb_info *sbi)
+{
+       struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+       if (dcc && dcc->f2fs_issue_discard) {
+               struct task_struct *discard_thread = dcc->f2fs_issue_discard;
+
+               dcc->f2fs_issue_discard = NULL;
+               kthread_stop(discard_thread);
+       }
+}
+
 /* This comes from f2fs_put_super */
 void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
 {
@@ -1422,12 +1434,7 @@ static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi)
        if (!dcc)
                return;
 
-       if (dcc->f2fs_issue_discard) {
-               struct task_struct *discard_thread = dcc->f2fs_issue_discard;
-
-               dcc->f2fs_issue_discard = NULL;
-               kthread_stop(discard_thread);
-       }
+       stop_discard_thread(sbi);
 
        kfree(dcc);
        SM_I(sbi)->dcc_info = NULL;

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c45bac6..f27c141 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -566,8 +566,6 @@ static void f2fs_put_super(struct super_block *sb)
        struct f2fs_sb_info *sbi = F2FS_SB(sb);
        int i;
 
-       stop_gc_thread(sbi);
-
        /* prevent remaining shrinker jobs */
        mutex_lock(&sbi->umount_mutex);
 
@@ -1976,8 +1974,11 @@ static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
 
 static void kill_f2fs_super(struct super_block *sb)
 {
-       if (sb->s_root)
+       if (sb->s_root) {
                set_sbi_flag(F2FS_SB(sb), SBI_IS_CLOSE);
+               stop_gc_thread(F2FS_SB(sb));
+               stop_discard_thread(F2FS_SB(sb));
+       }
        kill_block_super(sb);
 }