From 930d453995bdf4a0000bd162dfd4b70c6d7329f8 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 20 May 2019 09:29:45 -0700 Subject: fscrypt: handle blocksize < PAGE_SIZE in fscrypt_zeroout_range() Adjust fscrypt_zeroout_range() to encrypt a block at a time rather than a page at a time, so that it works when blocksize < PAGE_SIZE. This isn't optimized for performance, but then again this function already wasn't optimized for performance. As a future optimization, we could submit much larger bios here. This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. This is based on work by Chandan Rajendra. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers --- fs/crypto/bio.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'fs/crypto') diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c index 92b2d5da5d8e..f9111ffa12ff 100644 --- a/fs/crypto/bio.c +++ b/fs/crypto/bio.c @@ -72,12 +72,12 @@ EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio); int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, sector_t pblk, unsigned int len) { + const unsigned int blockbits = inode->i_blkbits; + const unsigned int blocksize = 1 << blockbits; struct page *ciphertext_page; struct bio *bio; int ret, err = 0; - BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE); - ciphertext_page = fscrypt_alloc_bounce_page(GFP_NOWAIT); if (!ciphertext_page) return -ENOMEM; @@ -85,7 +85,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, while (len--) { err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk, ZERO_PAGE(0), ciphertext_page, - PAGE_SIZE, 0, GFP_NOFS); + blocksize, 0, GFP_NOFS); if (err) goto errout; @@ -95,14 +95,11 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, goto errout; } bio_set_dev(bio, inode->i_sb->s_bdev); - bio->bi_iter.bi_sector = - pblk << (inode->i_sb->s_blocksize_bits - 9); + bio->bi_iter.bi_sector = pblk << (blockbits - 9); 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, blocksize, 0); + if (WARN_ON(ret != blocksize)) { /* should never happen! */ - WARN_ON(1); bio_put(bio); err = -EIO; goto errout; -- cgit v1.2.3-55-g7522