On Wed, Dec 22, 2021 at 09:06:22AM +0800, yebin wrote:

On 2021/12/21 22:43, Lukas Czerner wrote:

quoted

Hi,

nice catch. This is a bug indeed. However I am currently in a process of
changing the ctx_set/clear/test_ helpers because currently it generates
functions that are unused.

While I am at it I can just create a custom ctx_set_mount_flags()
helper that would behave as expected so that we won't have to specify
"1 < EXT4_MF_FS_ABORTED" which is not really obvious and hence error
prone.

Actually, I fixed the first version as follows:

Allright, this looks better.

Maybe ctx_set_mount_flag since you can't really set more than one this
way?

+{
+	set_bit(bit, &ctx->mask_s_mount_flags);
+	set_bit(bit, &ctx->vals_s_mount_flags);
+}


I think 'mask_s_mount_flags' is useless now.

So how would we know what flags have changed ? Sure, there is currently
no need to clear the flag but that can come in future and once it does
we'll only need to create a clear helper, the rest will be ready.
I'd rather keep it.

-Lukas

quoted

My plan is to send my patch set including this one tomorrow, will that
be fine with you ?

-Lukas

On Tue, Dec 21, 2021 at 08:32:14PM +0800, Ye Bin wrote:

quoted

We test remount with 'abort' option as follows:
[root@localhost home]# mount  /dev/sda test
[root@localhost home]# mount | grep test
/dev/sda on /home/test type ext4 (rw,relatime)
[root@localhost home]# mount -o remount,abort test
[root@localhost home]# mount | grep test
/dev/sda on /home/test type ext4 (rw,relatime)

Obviously, remount 'abort' option isn't effective.
After 6e47a3cc68fc commit we process abort option with 'ctx_set_mount_flags':
static inline void ctx_set_mount_flags(struct ext4_fs_context *ctx, int flag)
{
	ctx->mask_s_mount_flags |= flag;
	ctx->vals_s_mount_flags |= flag;
}

But we test 'abort' option with 'ext4_test_mount_flag':
static inline int ext4_test_mount_flag(struct super_block *sb, int bit)
{
         return test_bit(bit, &EXT4_SB(sb)->s_mount_flags);
}

To solve this issue, pass (1 <<  EXT4_MF_FS_ABORTED) to 'ctx_set_mount_flags'.

Fixes:6e47a3cc68fc("ext4: get rid of super block and sbi from handle_mount_ops()")
Signed-off-by: Ye Bin <redacted>
---
  fs/ext4/super.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b72d989b77fb..071b7b3c5678 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c

@@ -2236,7 +2236,7 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
  			 param->key);
  		return 0;
  	case Opt_abort:
-		ctx_set_mount_flags(ctx, EXT4_MF_FS_ABORTED);
+		ctx_set_mount_flags(ctx, 1 << EXT4_MF_FS_ABORTED);
  		return 0;
  	case Opt_i_version:
  		ctx_set_flags(ctx, SB_I_VERSION);

-- 
2.31.1

.