On Wed, Jul 22, 2020 at 03:34:04PM -0700, Eric Biggers wrote: > > Which means you are now placing a new constraint on this code in > > that we cannot ever, in future, zero entire blocks here. > > > > This code can issue arbitrary sized zeroing bios - multiple entire fs blocks > > blocks if necessary - so I think constraining it to only support > > partial block zeroing by adding a warning like this is no correct. > > In v3 and earlier this instead had the code to set an encryption context: > > fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, > GFP_KERNEL); > > Would you prefer that, even though the call to fscrypt_set_bio_crypt_ctx() would > always be a no-op currently (since for now, iomap_dio_zero() will never be > called with an encrypted file) and thus wouldn't be properly tested? > > BTW, iomap_dio_zero() is actually limited to one page, so it's not quite > "arbitrary sizes". I have a patch for that http://git.infradead.org/users/willy/pagecache.git/commitdiff/1a4d72a890ca9c2ea3d244a6153511ae674ce1d8 It's not going to cause a problem for crossing a 2^32 boundary because pages are naturally aligned and don't get that big.