2020-07-01 23:27:37

by Namjae Jeon

[permalink] [raw]
Subject: [PATCH 5.7.y 3/5] exfat: call sync_filesystem for read-only remount

From: Hyunchul Lee <[email protected]>

We need to commit dirty metadata and pages to disk
before remounting exfat as read-only.

This fixes a failure in xfstests generic/452

generic/452 does the following:
cp something <exfat>/
mount -o remount,ro <exfat>

the <exfat>/something is corrupted. because while
exfat is remounted as read-only, exfat doesn't
have a chance to commit metadata and
vfs invalidates page caches in a block device.

Fixes: 719c1e182916 ("exfat: add super block operations")
Cc: [email protected] # v5.7
Signed-off-by: Hyunchul Lee <[email protected]>
Acked-by: Sungjong Seo <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
---
fs/exfat/super.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index c1b1ed306a48..e87980153398 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -637,10 +637,20 @@ static void exfat_free(struct fs_context *fc)
}
}

+static int exfat_reconfigure(struct fs_context *fc)
+{
+ fc->sb_flags |= SB_NODIRATIME;
+
+ /* volume flag will be updated in exfat_sync_fs */
+ sync_filesystem(fc->root->d_sb);
+ return 0;
+}
+
static const struct fs_context_operations exfat_context_ops = {
.parse_param = exfat_parse_param,
.get_tree = exfat_get_tree,
.free = exfat_free,
+ .reconfigure = exfat_reconfigure,
};

static int exfat_init_fs_context(struct fs_context *fc)
--
2.17.1