fscrypt: pass a byte length to fscrypt_zeroout_range

Range lengths are usually expressed as bytes in the VFS, switch
fscrypt_zeroout_range to this convention.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260302141922.370070-13-hch@lst.de
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: Christoph Hellwig

fs/crypto/bio.c

@@ -115,28 +115,29 @@ static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode,
  * @inode: the file's inode
  * @pos: the first file position (in bytes) to zero out
  * @pblk: the first filesystem physical block to zero out
- * @len: number of blocks to zero out
+ * @len: bytes to zero out
  *
  * Zero out filesystem blocks in an encrypted regular file on-disk, i.e. write
  * ciphertext blocks which decrypt to the all-zeroes block.  The blocks must be
  * both logically and physically contiguous.  It's also assumed that the
- * filesystem only uses a single block device, ->s_bdev.
+ * filesystem only uses a single block device, ->s_bdev.  @len must be a
+ * multiple of the file system logical block size.
  *
  * Note that since each block uses a different IV, this involves writing a
  * different ciphertext to each block; we can't simply reuse the same one.
  *
  * Return: 0 on success; -errno on failure.
  */
 int fscrypt_zeroout_range(const struct inode *inode, loff_t pos,
-			  sector_t pblk, unsigned int len)
+			  sector_t pblk, u64 len)
 {
 	const struct fscrypt_inode_info *ci = fscrypt_get_inode_info_raw(inode);
 	const unsigned int du_bits = ci->ci_data_unit_bits;
 	const unsigned int du_size = 1U << du_bits;
 	const unsigned int du_per_page_bits = PAGE_SHIFT - du_bits;
 	const unsigned int du_per_page = 1U << du_per_page_bits;
 	u64 du_index = pos >> du_bits;
-	u64 du_remaining = (u64)len << (inode->i_blkbits - du_bits);
+	u64 du_remaining = len >> du_bits;
 	sector_t sector = pblk << (inode->i_blkbits - SECTOR_SHIFT);
 	struct page *pages[16]; /* write up to 16 pages at a time */
 	unsigned int nr_pages;
@@ -150,7 +151,7 @@ int fscrypt_zeroout_range(const struct inode *inode, loff_t pos,
 
 	if (fscrypt_inode_uses_inline_crypto(inode))
 		return fscrypt_zeroout_range_inline_crypt(inode, pos, sector,
-				(u64)len << inode->i_blkbits);
+							  len);
 
 	BUILD_BUG_ON(ARRAY_SIZE(pages) > BIO_MAX_VECS);
 	nr_pages = min_t(u64, ARRAY_SIZE(pages),

fs/ext4/inode.c

@@ -406,7 +406,8 @@ int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
 
 	if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
 		return fscrypt_zeroout_range(inode,
-				(loff_t)lblk << inode->i_blkbits, pblk, len);
+				(loff_t)lblk << inode->i_blkbits, pblk,
+				(u64)len << inode->i_blkbits);
 
 	ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
 	if (ret > 0)

fs/f2fs/file.c

@@ -4164,7 +4164,7 @@ static int f2fs_secure_erase(struct block_device *bdev, struct inode *inode,
 		if (IS_ENCRYPTED(inode))
 			ret = fscrypt_zeroout_range(inode,
 					(loff_t)off << inode->i_blkbits, block,
-					len);
+					(u64)len << inode->i_blkbits);
 		else
 			ret = blkdev_issue_zeroout(bdev, sector, nr_sects,
 					GFP_NOFS, 0);

include/linux/fscrypt.h

@@ -450,8 +450,8 @@ u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
 
 /* bio.c */
 bool fscrypt_decrypt_bio(struct bio *bio);
-int fscrypt_zeroout_range(const struct inode *inode, loff_t pos,
-			  sector_t pblk, unsigned int len);
+int fscrypt_zeroout_range(const struct inode *inode, loff_t pos, sector_t pblk,
+			  u64 len);
 
 /* hooks.c */
 int fscrypt_file_open(struct inode *inode, struct file *filp);
@@ -756,7 +756,7 @@ static inline bool fscrypt_decrypt_bio(struct bio *bio)
 }
 
 static inline int fscrypt_zeroout_range(const struct inode *inode, loff_t pos,
-					sector_t pblk, unsigned int len)
+					sector_t pblk, u64 len)
 {
 	return -EOPNOTSUPP;
 }