On Wed, Sep 13, 2017 at 05:37:53PM +0200, Philipp Guendisch wrote: > This patch adds a software based secure erase option to improve data > confidentiality. The CONFIG_BLK_DEV_SECURE_ERASE option enables a mount > flag called 'sw_secure_erase'. When you mount a volume with this flag, > every discard call is prepended by an explicit write command to overwrite > the data before it is discarded. A volume without a discard compatibility > can be used as well but the discard calls will be enabled for this device > and suppressed after the write call is made. How can this work with CoW filesystems? > > Built against torvalds/linux This should go below the '---' so git am doesn't write it into the changelog. [...] > + if (strcmp(fs_type->name, "ext4") != 0 && > + strcmp(fs_type->name, "btrfs") != 0 && > + strcmp(fs_type->name, "gfs2") != 0 && > + strcmp(fs_type->name, "gfs2meta") != 0 && > + strcmp(fs_type->name, "xfs") != 0 && > + strcmp(fs_type->name, "jfs") != 0) { > + pr_warn("fs: The mounted %s filesystem on drive %s does not generate discards, secure erase won't work", > + fs_type->name, dev_name); > + } > +skip: > +#endif Which filesystems commonly used in production are left afterwards? I'm sorry, but while I get that this sounds like a nice feature for a paper or reasearch project, I don't see why it should be used on production systems at all. Byte, Johannes -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850