Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

Pull fscrypt updates from Eric Biggers:

 - Preparations for supporting encryption on ext4 filesystems where the
   filesystem block size is smaller than PAGE_SIZE.

 - Don't allow setting encryption policies on dead directories.

 - Various cleanups.

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  fscrypt: document testing with xfstests
  fscrypt: remove selection of CONFIG_CRYPTO_SHA256
  fscrypt: remove unnecessary includes of ratelimit.h
  fscrypt: don't set policy for a dead directory
  ext4: encrypt only up to last block in ext4_bio_write_page()
  ext4: decrypt only the needed block in __ext4_block_zero_page_range()
  ext4: decrypt only the needed blocks in ext4_block_write_begin()
  ext4: clear BH_Uptodate flag on decryption error
  fscrypt: decrypt only the needed blocks in __fscrypt_decrypt_bio()
  fscrypt: support decrypting multiple filesystem blocks per page
  fscrypt: introduce fscrypt_decrypt_block_inplace()
  fscrypt: handle blocksize < PAGE_SIZE in fscrypt_zeroout_range()
  fscrypt: support encrypting multiple filesystem blocks per page
  fscrypt: introduce fscrypt_encrypt_block_inplace()
  fscrypt: clean up some BUG_ON()s in block encryption/decryption
  fscrypt: rename fscrypt_do_page_crypto() to fscrypt_crypt_block()
  fscrypt: remove the "write" part of struct fscrypt_ctx
  fscrypt: simplify bounce page handling

1 files changed, 23 insertions, 14 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c7f77c643008..f65357735a1a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1164,8 +1164,9 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 	int err = 0;
 	unsigned blocksize = inode->i_sb->s_blocksize;
 	unsigned bbits;
-	struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
-	bool decrypt = false;
+	struct buffer_head *bh, *head, *wait[2];
+	int nr_wait = 0;
+	int i;
 
 	BUG_ON(!PageLocked(page));
 	BUG_ON(from > PAGE_SIZE);
@@ -1217,23 +1218,32 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 		    !buffer_unwritten(bh) &&
 		    (block_start < from || block_end > to)) {
 			ll_rw_block(REQ_OP_READ, 0, 1, &bh);
-			*wait_bh++ = bh;
-			decrypt = IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode);
+			wait[nr_wait++] = bh;
 		}
 	}
 	/*
 	 * If we issued read requests, let them complete.
 	 */
-	while (wait_bh > wait) {
-		wait_on_buffer(*--wait_bh);
-		if (!buffer_uptodate(*wait_bh))
+	for (i = 0; i < nr_wait; i++) {
+		wait_on_buffer(wait[i]);
+		if (!buffer_uptodate(wait[i]))
 			err = -EIO;
 	}
-	if (unlikely(err))
+	if (unlikely(err)) {
 		page_zero_new_buffers(page, from, to);
-	else if (decrypt)
-		err = fscrypt_decrypt_page(page->mapping->host, page,
-				PAGE_SIZE, 0, page->index);
+	} else if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode)) {
+		for (i = 0; i < nr_wait; i++) {
+			int err2;
+
+			err2 = fscrypt_decrypt_pagecache_blocks(page, blocksize,
+								bh_offset(wait[i]));
+			if (err2) {
+				clear_buffer_uptodate(wait[i]);
+				err = err2;
+			}
+		}
+	}
+
 	return err;
 }
 #endif
@@ -4065,9 +4075,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 		if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode)) {
 			/* We expect the key to be set. */
 			BUG_ON(!fscrypt_has_encryption_key(inode));
-			BUG_ON(blocksize != PAGE_SIZE);
-			WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host,
-						page, PAGE_SIZE, 0, page->index));
+			WARN_ON_ONCE(fscrypt_decrypt_pagecache_blocks(
+					page, blocksize, bh_offset(bh)));
 		}
 	}
 	if (ext4_should_journal_data(inode)) {