On Wed, Aug 04, 2021 at 12:44:38AM +0100, Matthew Wilcox wrote: > > I don't understand how so many ntfs-classic xfstests pass: > > config NTFS_RW > bool "NTFS write support" > depends on NTFS_FS > help > This enables the partial, but safe, write support in the NTFS driver. > > The only supported operation is overwriting existing files, without > changing the file length. No file or directory creation, deletion or > renaming is possible. Note only non-resident files can be written to > so you may find that some very small files (<500 bytes or so) cannot > be written to. > > Are the tests really passing, or just claiming to pass? This was the ntfs provided by the Debian package ntfs-3g (which is the only source of a mkfs.ntfs that I could find, BTW). This is a fuse-based ntfs, not the in-kernel ntfs file system. Apologies for not making that clear. <tytso.root@cwcc> {/usr/projects/linux/ext4}, level 2 (ntfs3) 1003# mkfs.ntfs /dev/cwcc-vg/scratch Cluster size has been automatically set to 4096 bytes. Initializing device with zeroes: 100% - Done. Creating NTFS volume structures. mkntfs completed successfully. Have a nice day. <tytso.root@cwcc> {/usr/projects/linux/ext4}, level 2 (ntfs3) 1004# mount -t ntfs /dev/cwcc-vg/scratch /mnt <tytso.root@cwcc> {/usr/projects/linux/ext4}, level 2 (ntfs3) 1005# grep /mnt /proc/mounts /dev/mapper/cwcc--vg-scratch /mnt fuseblk rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096 0 0 TBH, I had forgotten that we had an in-kernel ntfs implementation. Whenver I've ever needed to access ntfs files, I've always used the ntfs-3g FUSE package. - Ted