xfs: allow ro mounts if rtdev or logdev are read-only

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@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
This commit is contained in:
Hans Holmberg 2025-04-30 08:35:34 +00:00 committed by Carlos Maiolino
parent 5088aad3d3
commit bfecc4091e

View file

@ -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");