fscrypt: pass a byte length to fscrypt_zeroout_range_inline_crypt

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260302141922.370070-11-hch@lst.de
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: Christoph Hellwig

fs/crypto/bio.c

@@ -71,10 +71,8 @@ static void fscrypt_zeroout_range_end_io(struct bio *bio)
 
 static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode,
 					      loff_t pos, sector_t sector,
-					      unsigned int len)
+					      u64 len)
 {
-	const unsigned int blockbits = inode->i_blkbits;
-	const unsigned int blocks_per_page = 1 << (PAGE_SHIFT - blockbits);
 	struct fscrypt_zero_done done = {
 		.pending	= ATOMIC_INIT(1),
 		.done		= COMPLETION_INITIALIZER_ONSTACK(done.done),
@@ -92,12 +90,10 @@ static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode,
 		fscrypt_set_bio_crypt_ctx(bio, inode, pos, GFP_NOFS);
 
 		for (n = 0; n < BIO_MAX_VECS; n++) {
-			unsigned int blocks_this_page =
-				min(len, blocks_per_page);
-			unsigned int bytes_this_page = blocks_this_page << blockbits;
+			unsigned int bytes_this_page = min(len, PAGE_SIZE);
 
 			__bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0);
-			len -= blocks_this_page;
+			len -= bytes_this_page;
 			pos += bytes_this_page;
 			sector += (bytes_this_page >> SECTOR_SHIFT);
 			if (!len || !fscrypt_mergeable_bio(bio, inode, pos))
@@ -155,7 +151,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 
 	if (fscrypt_inode_uses_inline_crypto(inode))
 		return fscrypt_zeroout_range_inline_crypt(inode, pos, sector,
-							  len);
+				(u64)len << inode->i_blkbits);
 
 	BUILD_BUG_ON(ARRAY_SIZE(pages) > BIO_MAX_VECS);
 	nr_pages = min_t(u64, ARRAY_SIZE(pages),