[f2fs-dev] [PATCH V2 12/13] fscrypt_zeroout_range: Encrypt all zeroed out blocks of a page

[Chandan Rajendra]

For subpage-sized blocks, this commit adds code to encrypt all zeroed
out blocks mapped by a page.

Signed-off-by: Chandan Rajendra <chan...@linux.ibm.com>
---
 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;
        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;
 
-       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;
+               }
 
                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);
                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);
-- 
2.19.1



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