Allow read-only mounts on rtdevs and logdevs that are marked as
read-only and make sure those mounts can't be remounted read-write.
Use the sb_open_mode helper to make sure that we don't try to open
devices with write access enabled for read-only mounts.
Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxx>
---
Changes since v1:
- Switched to using the sb_open_mode helper that does exactly
what we want.
fs/xfs/xfs_super.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index b2dd0c0bf509..5e456a6073ca 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -380,10 +380,11 @@ xfs_blkdev_get(
struct file **bdev_filep)
{
int error = 0;
+ blk_mode_t mode;
- *bdev_filep = bdev_file_open_by_path(name,
- BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
- mp->m_super, &fs_holder_ops);
+ mode = sb_open_mode(mp->m_super->s_flags);
+ *bdev_filep = bdev_file_open_by_path(name, mode,
+ mp->m_super, &fs_holder_ops);
if (IS_ERR(*bdev_filep)) {
error = PTR_ERR(*bdev_filep);
*bdev_filep = NULL;
@@ -1969,6 +1970,20 @@ xfs_remount_rw(
struct xfs_sb *sbp = &mp->m_sb;
int error;
+ if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp &&
+ bdev_read_only(mp->m_logdev_targp->bt_bdev)) {
+ xfs_warn(mp,
+ "ro->rw transition prohibited by read-only logdev");
+ return -EACCES;
+ }
+
+ if (mp->m_rtdev_targp &&
+ bdev_read_only(mp->m_rtdev_targp->bt_bdev)) {
+ xfs_warn(mp,
+ "ro->rw transition prohibited by read-only rtdev");
+ return -EACCES;
+ }
+
if (xfs_has_norecovery(mp)) {
xfs_warn(mp,
"ro->rw transition prohibited on norecovery mount");
--
2.34.1
