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From: Chandan Rajendra <chandan@linux.vnet.ibm.com>
To: linux-ext4@vger.kernel.org
Cc: Chandan Rajendra <chandan@linux.vnet.ibm.com>,
	linux-fsdevel@vger.kernel.org, tytso@mit.edu
Subject: [RFC PATCH 3/8] ext4: decrypt all contiguous blocks in a page
Date: Fri, 12 Jan 2018 19:41:24 +0530	[thread overview]
Message-ID: <20180112141129.27507-4-chandan@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180112141129.27507-1-chandan@linux.vnet.ibm.com>

With blocksize < pagesize, a page can contain more than one block. Hence
this commit changes completion_pages() to invoke fscrypt_decrypt_page()
in order to decrypt all the contiguous blocks mapped by the page.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
 fs/crypto/bio.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index 0d5e6a5..eb6e06a 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -40,8 +40,23 @@ static void completion_pages(struct work_struct *work)
 
 	bio_for_each_segment_all(bv, bio, i) {
 		struct page *page = bv->bv_page;
-		int ret = fscrypt_decrypt_page(page->mapping->host, page,
-				PAGE_SIZE, 0, page->index);
+		struct inode *inode = page->mapping->host;
+		const unsigned long blocksize = inode->i_sb->s_blocksize;
+		const unsigned blkbits = inode->i_blkbits;
+		int page_blk = page->index << (PAGE_SHIFT - blkbits);
+		int blk = page_blk + (bv->bv_offset >> blkbits);
+		int nr_blks = bv->bv_len >> blkbits;
+		int ret = 0;
+		int j;
+
+		for (j = 0; j < nr_blks; j++, blk++) {
+			ret = fscrypt_decrypt_page(page->mapping->host,
+						page, blocksize,
+						bv->bv_offset + (j << blkbits),
+						blk);
+			if (ret)
+				break;
+		}
 
 		if (ret) {
 			WARN_ON_ONCE(1);
-- 
2.9.5

  parent reply	other threads:[~2018-01-12 14:10 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-12 14:11 [RFC PATCH 0/8] Ext4 encryption support for blocksize < pagesize Chandan Rajendra
2018-01-12 14:11 ` [RFC PATCH 1/8] ext4: use EXT4_INODE_ENCRYPT flag to detect encrypted bio Chandan Rajendra
2018-01-12 19:04   ` Randy Dunlap
2018-01-13  5:22     ` Chandan Rajendra
2018-01-12 14:11 ` [RFC PATCH 2/8] fs/buffer.c: make some functions non-static Chandan Rajendra
2018-01-12 14:38   ` Matthew Wilcox
2018-01-13  5:25     ` Chandan Rajendra
2018-01-17  2:14   ` Eric Biggers
2018-01-12 14:11 ` Chandan Rajendra [this message]
2018-01-17  2:18   ` [RFC PATCH 3/8] ext4: decrypt all contiguous blocks in a page Eric Biggers
2018-01-12 14:11 ` [RFC PATCH 4/8] ext4: decrypt all boundary blocks when doing buffered write Chandan Rajendra
2018-01-17  2:22   ` Eric Biggers
2018-01-12 14:11 ` [RFC PATCH 5/8] ext4: decrypt the block that needs to be partially zeroed Chandan Rajendra
2018-01-17  2:23   ` Eric Biggers
2018-01-12 14:11 ` [RFC PATCH 6/8] ext4: encrypt blocks whose size is less than page size Chandan Rajendra
2018-01-17  2:33   ` Eric Biggers
2018-01-12 14:11 ` [RFC PATCH 7/8] ext4: decrypt " Chandan Rajendra
2018-01-17  2:39   ` Eric Biggers
2018-01-12 14:11 ` [RFC PATCH 8/8] ext4: enable encryption for blocksize " Chandan Rajendra
2018-01-17  2:40   ` Eric Biggers
2018-01-17 13:42     ` Chandan Rajendra
2018-01-12 19:07 ` [RFC PATCH 0/8] Ext4 encryption support for blocksize < pagesize Randy Dunlap
2018-01-13  5:28   ` Chandan Rajendra
2018-01-13 12:48     ` Matthew Wilcox
2018-01-13 18:20       ` Randy Dunlap
2018-01-17  2:10 ` Eric Biggers
2018-01-17 13:43   ` Chandan Rajendra

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