From bfecc4091e07a47696ac922783216d9e9ea46c97 Mon Sep 17 00:00:00 2001 From: Hans Holmberg Date: Wed, 30 Apr 2025 08:35:34 +0000 Subject: [PATCH] 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 Reviewed-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Signed-off-by: Carlos Maiolino --- 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"); -- 2.25.1