On Tuesday, April 30, 2019 10:21:15 PM IST Eric Biggers wrote: > On Sun, Apr 28, 2019 at 10:01:20AM +0530, Chandan Rajendra wrote: > > For subpage-sized blocks, this commit adds code to encrypt all zeroed > > out blocks mapped by a page. > > > > Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxx> > > --- > > fs/crypto/bio.c | 40 ++++++++++++++++++---------------------- > > 1 file changed, 18 insertions(+), 22 deletions(-) > > > > diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c > > index 856f4694902d..46dd2ec50c7d 100644 > > --- a/fs/crypto/bio.c > > +++ b/fs/crypto/bio.c > > @@ -108,29 +108,23 @@ EXPORT_SYMBOL(fscrypt_pullback_bio_page); > > int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, > > sector_t pblk, unsigned int len) > > { > > - struct fscrypt_ctx *ctx; > > struct page *ciphertext_page = NULL; > > struct bio *bio; > > + u64 total_bytes, page_bytes; > > page_bytes should be 'unsigned int', since it's <= PAGE_SIZE. > > > int ret, err = 0; > > > > - BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE); > > - > > - ctx = fscrypt_get_ctx(inode, GFP_NOFS); > > - if (IS_ERR(ctx)) > > - return PTR_ERR(ctx); > > + total_bytes = len << inode->i_blkbits; > > Should cast len to 'u64' here, in case it's greater than UINT_MAX / blocksize. > > > > > - ciphertext_page = fscrypt_alloc_bounce_page(ctx, GFP_NOWAIT); > > - if (IS_ERR(ciphertext_page)) { > > - err = PTR_ERR(ciphertext_page); > > - goto errout; > > - } > > + while (total_bytes) { > > + page_bytes = min_t(u64, total_bytes, PAGE_SIZE); > > > > - while (len--) { > > - err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk, > > - ZERO_PAGE(0), ciphertext_page, > > - PAGE_SIZE, 0, GFP_NOFS); > > - if (err) > > + ciphertext_page = fscrypt_encrypt_page(inode, ZERO_PAGE(0), > > + page_bytes, 0, lblk, GFP_NOFS); > > + if (IS_ERR(ciphertext_page)) { > > + err = PTR_ERR(ciphertext_page); > > + ciphertext_page = NULL; > > goto errout; > > + } > > 'ciphertext_page' is leaked after each loop iteration. Did you mean to free it, > or did you mean to reuse it for subsequent iterations? Thanks for pointing this out. I actually meant to free it. I will see if I can reuse ciphertext_page in my next patchset rather than freeing and allocating it each time the loop is executed. > > > > > bio = bio_alloc(GFP_NOWAIT, 1); > > if (!bio) { > > @@ -141,9 +135,8 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, > > bio->bi_iter.bi_sector = > > pblk << (inode->i_sb->s_blocksize_bits - 9); > > This line uses ->s_blocksize_bits, but your new code uses ->i_blkbits. AFAIK > they'll always be the same, but please pick one or the other to use. I will fix this. > > > bio_set_op_attrs(bio, REQ_OP_WRITE, 0); > > - ret = bio_add_page(bio, ciphertext_page, > > - inode->i_sb->s_blocksize, 0); > > - if (ret != inode->i_sb->s_blocksize) { > > + ret = bio_add_page(bio, ciphertext_page, page_bytes, 0); > > + if (ret != page_bytes) { > > /* should never happen! */ > > WARN_ON(1); > > bio_put(bio); > > @@ -156,12 +149,15 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, > > bio_put(bio); > > if (err) > > goto errout; > > - lblk++; > > - pblk++; > > + > > + lblk += page_bytes >> inode->i_blkbits; > > + pblk += page_bytes >> inode->i_blkbits; > > + total_bytes -= page_bytes; > > } > > err = 0; > > errout: > > - fscrypt_release_ctx(ctx); > > + if (!IS_ERR_OR_NULL(ciphertext_page)) > > + fscrypt_restore_control_page(ciphertext_page); > > return err; > > } > > EXPORT_SYMBOL(fscrypt_zeroout_range); > > -- chandan
![]() |