f2fs: Fix the race condition of resize flag between resizefs

[ Upstream commit 28fc4e9077ce59ab28c89c20dc6be5154473218f ]

Because the set/clear SBI_IS_RESIZEFS flag not between any locks,
In the following case:
  thread1			thread2
   ->ioctl(resizefs)
    ->set RESIZEFS flag		 ->ioctl(resizefs)
    ...                   	  ->set RESIZEFS flag
    ->clear RESIZEFS flag
    				  ->resizefs stream
				    # No RESIZEFS flag in the stream

Also before freeze_super, the resizefs not started, we should not set
the SBI_IS_RESIZEFS flag.

So move the set/clear SBI_IS_RESIZEFS flag between the cp_mutex and
gc_lock.

Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 4546e01..2a9d825 100644 (file)
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -2133,8 +2133,6 @@ out_unlock:
        if (err)
                return err;
 
-       set_sbi_flag(sbi, SBI_IS_RESIZEFS);
-
        freeze_super(sbi->sb);
        f2fs_down_write(&sbi->gc_lock);
        f2fs_down_write(&sbi->cp_global_sem);
@@ -2150,6 +2148,7 @@ out_unlock:
        if (err)
                goto out_err;
 
+       set_sbi_flag(sbi, SBI_IS_RESIZEFS);
        err = free_segment_range(sbi, secs, false);
        if (err)
                goto recover_out;
@@ -2173,6 +2172,7 @@ out_unlock:
                f2fs_commit_super(sbi, false);
        }
 recover_out:
+       clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
        if (err) {
                set_sbi_flag(sbi, SBI_NEED_FSCK);
                f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
@@ -2185,6 +2185,5 @@ out_err:
        f2fs_up_write(&sbi->cp_global_sem);
        f2fs_up_write(&sbi->gc_lock);
        thaw_super(sbi->sb);
-       clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
        return err;
 }