diff mbox series

[v2,19/20] btrfs: encrypt normal file extent data if appropriate

Message ID 947e7f9899e2562063034587613c779ff3eac34a.1662420176.git.sweettea-kernel@dorminy.me (mailing list archive)
State Superseded
Headers show
Series btrfs: add fscrypt integration | expand

Commit Message

Sweet Tea Dorminy Sept. 6, 2022, 12:35 a.m. UTC
From: Omar Sandoval <osandov@osandov.com>

Add in the necessary calls to encrypt and decrypt data to achieve
encryption of normal data.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
---
 fs/btrfs/extent_io.c    | 56 ++++++++++++++++++++++++++++++++++++-----
 fs/btrfs/file-item.c    |  9 +++++--
 fs/btrfs/fscrypt.c      | 23 ++++++++++++++++-
 fs/btrfs/tree-checker.c | 11 +++++---
 4 files changed, 87 insertions(+), 12 deletions(-)

Comments

Josef Bacik Sept. 8, 2022, 8:19 p.m. UTC | #1
On Mon, Sep 05, 2022 at 08:35:34PM -0400, Sweet Tea Dorminy wrote:
> From: Omar Sandoval <osandov@osandov.com>
> 
> Add in the necessary calls to encrypt and decrypt data to achieve
> encryption of normal data.
>

A little more description of what these bounce pages are and what we're doing
with them.
 
> Signed-off-by: Omar Sandoval <osandov@osandov.com>
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
> ---
>  fs/btrfs/extent_io.c    | 56 ++++++++++++++++++++++++++++++++++++-----
>  fs/btrfs/file-item.c    |  9 +++++--
>  fs/btrfs/fscrypt.c      | 23 ++++++++++++++++-
>  fs/btrfs/tree-checker.c | 11 +++++---
>  4 files changed, 87 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index a467a7553bd9..8adcee599844 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -183,6 +183,7 @@ static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
>  {
>  	struct bio *bio;
>  	struct bio_vec *bv;
> +	struct page *first_page;
>  	struct inode *inode;
>  	int mirror_num;
>  
> @@ -191,13 +192,17 @@ static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
>  
>  	bio = bio_ctrl->bio;
>  	bv = bio_first_bvec_all(bio);
> -	inode = bv->bv_page->mapping->host;
> +	first_page = bio_first_page_all(bio);
> +	if (fscrypt_is_bounce_page(first_page))
> +		inode = fscrypt_pagecache_page(first_page)->mapping->host;
> +	else
> +		inode = first_page->mapping->host;
>  	mirror_num = bio_ctrl->mirror_num;
>  
>  	/* Caller should ensure the bio has at least some range added */
>  	ASSERT(bio->bi_iter.bi_size);
>  
> -	btrfs_bio(bio)->file_offset = page_offset(bv->bv_page) + bv->bv_offset;
> +	btrfs_bio(bio)->file_offset = page_offset(first_page) + bv->bv_offset;
>  
>  	if (!is_data_inode(inode))
>  		btrfs_submit_metadata_bio(inode, bio, mirror_num);
> @@ -2810,9 +2815,19 @@ static void end_bio_extent_writepage(struct btrfs_bio *bbio)
>  	ASSERT(!bio_flagged(bio, BIO_CLONED));
>  	bio_for_each_segment_all(bvec, bio, iter_all) {
>  		struct page *page = bvec->bv_page;
> -		struct inode *inode = page->mapping->host;
> -		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> -		const u32 sectorsize = fs_info->sectorsize;
> +		struct inode *inode;
> +		struct btrfs_fs_info *fs_info;
> +		u32 sectorsize;
> +		struct page *bounce_page = NULL;
> +
> +		if (fscrypt_is_bounce_page(page)) {
> +			bounce_page = page;
> +			page = fscrypt_pagecache_page(bounce_page);
> +		}
> +
> +		inode = page->mapping->host;
> +		fs_info = btrfs_sb(inode->i_sb);
> +		sectorsize = fs_info->sectorsize;
>  
>  		/* Our read/write should always be sector aligned. */
>  		if (!IS_ALIGNED(bvec->bv_offset, sectorsize))
> @@ -2833,7 +2848,7 @@ static void end_bio_extent_writepage(struct btrfs_bio *bbio)
>  		}
>  
>  		end_extent_writepage(page, error, start, end);
> -
> +		fscrypt_free_bounce_page(bounce_page);
>  		btrfs_page_clear_writeback(fs_info, page, start, bvec->bv_len);
>  	}
>  
> @@ -3029,6 +3044,17 @@ static void end_bio_extent_readpage(struct btrfs_bio *bbio)
>  			}
>  		}
>  
> +		if (likely(uptodate)) {
> +			if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
> +				int ret = fscrypt_decrypt_pagecache_blocks(page,
> +									   bvec->bv_len,
> +									   bvec->bv_offset);
> +				if (ret) {
> +					error_bitmap = (unsigned int) -1;
> +					uptodate = false;
> +					}

This thing.  Thanks,

Josef
diff mbox series

Patch

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a467a7553bd9..8adcee599844 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -183,6 +183,7 @@  static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
 {
 	struct bio *bio;
 	struct bio_vec *bv;
+	struct page *first_page;
 	struct inode *inode;
 	int mirror_num;
 
@@ -191,13 +192,17 @@  static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
 
 	bio = bio_ctrl->bio;
 	bv = bio_first_bvec_all(bio);
-	inode = bv->bv_page->mapping->host;
+	first_page = bio_first_page_all(bio);
+	if (fscrypt_is_bounce_page(first_page))
+		inode = fscrypt_pagecache_page(first_page)->mapping->host;
+	else
+		inode = first_page->mapping->host;
 	mirror_num = bio_ctrl->mirror_num;
 
 	/* Caller should ensure the bio has at least some range added */
 	ASSERT(bio->bi_iter.bi_size);
 
-	btrfs_bio(bio)->file_offset = page_offset(bv->bv_page) + bv->bv_offset;
+	btrfs_bio(bio)->file_offset = page_offset(first_page) + bv->bv_offset;
 
 	if (!is_data_inode(inode))
 		btrfs_submit_metadata_bio(inode, bio, mirror_num);
@@ -2810,9 +2815,19 @@  static void end_bio_extent_writepage(struct btrfs_bio *bbio)
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
 	bio_for_each_segment_all(bvec, bio, iter_all) {
 		struct page *page = bvec->bv_page;
-		struct inode *inode = page->mapping->host;
-		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-		const u32 sectorsize = fs_info->sectorsize;
+		struct inode *inode;
+		struct btrfs_fs_info *fs_info;
+		u32 sectorsize;
+		struct page *bounce_page = NULL;
+
+		if (fscrypt_is_bounce_page(page)) {
+			bounce_page = page;
+			page = fscrypt_pagecache_page(bounce_page);
+		}
+
+		inode = page->mapping->host;
+		fs_info = btrfs_sb(inode->i_sb);
+		sectorsize = fs_info->sectorsize;
 
 		/* Our read/write should always be sector aligned. */
 		if (!IS_ALIGNED(bvec->bv_offset, sectorsize))
@@ -2833,7 +2848,7 @@  static void end_bio_extent_writepage(struct btrfs_bio *bbio)
 		}
 
 		end_extent_writepage(page, error, start, end);
-
+		fscrypt_free_bounce_page(bounce_page);
 		btrfs_page_clear_writeback(fs_info, page, start, bvec->bv_len);
 	}
 
@@ -3029,6 +3044,17 @@  static void end_bio_extent_readpage(struct btrfs_bio *bbio)
 			}
 		}
 
+		if (likely(uptodate)) {
+			if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
+				int ret = fscrypt_decrypt_pagecache_blocks(page,
+									   bvec->bv_len,
+									   bvec->bv_offset);
+				if (ret) {
+					error_bitmap = (unsigned int) -1;
+					uptodate = false;
+					}
+			}
+		}
 		if (likely(uptodate)) {
 			loff_t i_size = i_size_read(inode);
 			pgoff_t end_index = i_size >> PAGE_SHIFT;
@@ -3364,11 +3390,29 @@  static int submit_extent_page(blk_opf_t opf,
 			      bool force_bio_submit)
 {
 	int ret = 0;
+	struct page *bounce_page = NULL;
 	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
 	unsigned int cur = pg_offset;
 
 	ASSERT(bio_ctrl);
 
+	if ((opf & REQ_OP_MASK) == REQ_OP_WRITE &&
+	    fscrypt_inode_uses_fs_layer_crypto(&inode->vfs_inode)) {
+		gfp_t gfp_flags = GFP_NOFS;
+
+		if (bio_ctrl->bio)
+			gfp_flags = GFP_NOWAIT | __GFP_NOWARN;
+		else
+			gfp_flags = GFP_NOFS;
+		bounce_page = fscrypt_encrypt_pagecache_blocks(page, size,
+							       pg_offset,
+							       gfp_flags);
+		if (IS_ERR(bounce_page))
+			return PTR_ERR(bounce_page);
+		page = bounce_page;
+		pg_offset = 0;
+	}
+
 	ASSERT(pg_offset < PAGE_SIZE && size <= PAGE_SIZE &&
 	       pg_offset + size <= PAGE_SIZE);
 	if (force_bio_submit)
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ec2950656ddc..4a2a5cf73e9b 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -663,8 +663,13 @@  blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 	shash->tfm = fs_info->csum_shash;
 
 	bio_for_each_segment(bvec, bio, iter) {
-		if (use_page_offsets)
-			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
+		if (use_page_offsets) {
+			struct page *page = bvec.bv_page;
+
+			if (fscrypt_is_bounce_page(page))
+				page = fscrypt_pagecache_page(page);
+			offset = page_offset(page) + bvec.bv_offset;
+		}
 
 		if (!ordered) {
 			ordered = btrfs_lookup_ordered_extent(inode, offset);
diff --git a/fs/btrfs/fscrypt.c b/fs/btrfs/fscrypt.c
index c52a5a8788dd..edde09d22b7a 100644
--- a/fs/btrfs/fscrypt.c
+++ b/fs/btrfs/fscrypt.c
@@ -200,7 +200,28 @@  static int btrfs_fscrypt_get_extent_context(const struct inode *inode,
 					    size_t *extent_offset,
 					    size_t *extent_length)
 {
-	return len;
+	u64 offset = lblk_num << inode->i_blkbits;
+	struct extent_map *em;
+
+	/* Since IO must be in progress on this extent, this must succeed */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, PAGE_SIZE);
+	if (em) {
+		int ret = em->fscrypt_context.len;
+		if (ctx)
+			memcpy(ctx, em->fscrypt_context.buffer,
+			       em->fscrypt_context.len);
+
+		if (extent_offset)
+			*extent_offset
+				 = (offset - em->start) >> inode->i_blkbits;
+
+		if (extent_length)
+			*extent_length = em->len >> inode->i_blkbits;
+
+		free_extent_map(em);
+		return ret;
+	}
+	return -EINVAL;
 }
 
 static int btrfs_fscrypt_set_extent_context(void *extent, void *ctx,
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index a78b2882df1b..3115acdc360f 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -273,9 +273,14 @@  static int check_extent_data_item(struct extent_buffer *leaf,
 			return -EUCLEAN;
 		}
 
-		/* Compressed inline extent has no on-disk size, skip it */
-		if (btrfs_file_extent_compression(leaf, fi) !=
-		    BTRFS_COMPRESS_NONE)
+		/*
+		 * Compressed inline extent has no on-disk size; encrypted has
+		 * variable size; skip them
+		 */
+		if ((btrfs_file_extent_compression(leaf, fi) !=
+		     BTRFS_COMPRESS_NONE) ||
+		    (btrfs_file_extent_encryption(leaf, fi) !=
+		     BTRFS_ENCRYPTION_NONE))
 			return 0;
 
 		/* Uncompressed inline extent size must match item size */