On Wed, Oct 21, 2020 at 09:21:36AM +0000, Damien Le Moal wrote: > > + * submit_bio_direct - submit a bio to the block device layer for I/O > > + * bypass filter. > > + * @bio: The bio describing the location in memory and on the device. > > * > > + * Description: You don't need this line. > > + * This is a version of submit_bio() that shall only be used for I/O > > + * that cannot be intercepted by block layer filters. > > + * All file systems and other upper level users of the block layer > > + * should use submit_bio() instead. > > + * Use this function to access the swap partition and directly access > > + * the block device file. I don't understand why O_DIRECT gets to bypass the block filter. Nor do I understand why anybody would place a block filter on the swap device. But if somebody did place a filter on the swap device, why should swap be able to bypass the filter?
