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Date:   Fri, 21 Feb 2020 03:50:49 -0800
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Subject: [PATCH v7 8/9] f2fs: add inline encryption support
From:   Satya Tangirala <satyat@google.com>
To:     linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
        linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org
Cc:     Barani Muthukumaran <bmuthuku@qti.qualcomm.com>,
        Kuohong Wang <kuohong.wang@mediatek.com>,
        Kim Boojin <boojin.kim@samsung.com>,
        Satya Tangirala <satyat@google.com>,
        Eric Biggers <ebiggers@google.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

Wire up f2fs to support inline encryption via the helper functions which
fs/crypto/ now provides.  This includes:

- Adding a mount option 'inlinecrypt' which enables inline encryption
  on encrypted files where it can be used.

- Setting the bio_crypt_ctx on bios that will be submitted to an
  inline-encrypted file.

- Not adding logically discontiguous data to bios that will be submitted
  to an inline-encrypted file.

- Not doing filesystem-layer crypto on inline-encrypted files.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
---
 Documentation/filesystems/f2fs.txt |  4 ++
 fs/f2fs/compress.c                 |  2 +-
 fs/f2fs/data.c                     | 67 +++++++++++++++++++++++++-----
 fs/f2fs/f2fs.h                     |  3 ++
 fs/f2fs/super.c                    | 35 ++++++++++++++++
 5 files changed, 100 insertions(+), 11 deletions(-)

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 4eb3e2ddd00e..e8d6a9240f55 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -246,6 +246,10 @@ compress_extension=%s  Support adding specified extension, so that f2fs can enab
                        on compression extension list and enable compression on
                        these file by default rather than to enable it via ioctl.
                        For other files, we can still enable compression via ioctl.
+inlinecrypt
+                       Use blk-crypto, rather than fscrypt, for file content
+                       en/decryption. See
+                       Documentation/block/inline-encryption.rst
 
 ================================================================================
 DEBUGFS ENTRIES
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index d8a64be90a50..6ae313ea5432 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -775,7 +775,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 		.need_lock = LOCK_RETRY,
 		.io_type = io_type,
 		.io_wbc = wbc,
-		.encrypted = f2fs_encrypted_file(cc->inode),
+		.encrypted = fscrypt_inode_uses_fs_layer_crypto(cc->inode),
 	};
 	struct dnode_of_data dn;
 	struct node_info ni;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b27b72107911..6d42ecceb08b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -436,6 +436,33 @@ static struct bio *__bio_alloc(struct f2fs_io_info *fio, int npages)
 	return bio;
 }
 
+static void f2fs_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode,
+				  pgoff_t first_idx,
+				  const struct f2fs_io_info *fio,
+				  gfp_t gfp_mask)
+{
+	/*
+	 * The f2fs garbage collector sets ->encrypted_page when it wants to
+	 * read/write raw data without encryption.
+	 */
+	if (!fio || !fio->encrypted_page)
+		fscrypt_set_bio_crypt_ctx(bio, inode, first_idx, gfp_mask);
+}
+
+static bool f2fs_crypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+				     pgoff_t next_idx,
+				     const struct f2fs_io_info *fio)
+{
+	/*
+	 * The f2fs garbage collector sets ->encrypted_page when it wants to
+	 * read/write raw data without encryption.
+	 */
+	if (fio && fio->encrypted_page)
+		return !bio_has_crypt_ctx(bio);
+
+	return fscrypt_mergeable_bio(bio, inode, next_idx);
+}
+
 static inline void __submit_bio(struct f2fs_sb_info *sbi,
 				struct bio *bio, enum page_type type)
 {
@@ -632,6 +659,9 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 	/* Allocate a new bio */
 	bio = __bio_alloc(fio, 1);
 
+	f2fs_set_bio_crypt_ctx(bio, fio->page->mapping->host,
+			       fio->page->index, fio, GFP_NOIO);
+
 	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 		bio_put(bio);
 		return -EFAULT;
@@ -820,12 +850,16 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
 	trace_f2fs_submit_page_bio(page, fio);
 	f2fs_trace_ios(fio, 0);
 
-	if (bio && !page_is_mergeable(fio->sbi, bio, *fio->last_block,
-						fio->new_blkaddr))
+	if (bio && (!page_is_mergeable(fio->sbi, bio, *fio->last_block,
+				       fio->new_blkaddr) ||
+		    !f2fs_crypt_mergeable_bio(bio, fio->page->mapping->host,
+					      fio->page->index, fio)))
 		f2fs_submit_merged_ipu_write(fio->sbi, &bio, NULL);
 alloc_new:
 	if (!bio) {
 		bio = __bio_alloc(fio, BIO_MAX_PAGES);
+		f2fs_set_bio_crypt_ctx(bio, fio->page->mapping->host,
+				       fio->page->index, fio, GFP_NOIO);
 		bio_set_op_attrs(bio, fio->op, fio->op_flags);
 
 		add_bio_entry(fio->sbi, bio, page, fio->temp);
@@ -882,8 +916,11 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 
 	inc_page_count(sbi, WB_DATA_TYPE(bio_page));
 
-	if (io->bio && !io_is_mergeable(sbi, io->bio, io, fio,
-			io->last_block_in_bio, fio->new_blkaddr))
+	if (io->bio &&
+	    (!io_is_mergeable(sbi, io->bio, io, fio, io->last_block_in_bio,
+			      fio->new_blkaddr) ||
+	     !f2fs_crypt_mergeable_bio(io->bio, fio->page->mapping->host,
+				       fio->page->index, fio)))
 		__submit_merged_bio(io);
 alloc_new:
 	if (io->bio == NULL) {
@@ -895,6 +932,8 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 			goto skip;
 		}
 		io->bio = __bio_alloc(fio, BIO_MAX_PAGES);
+		f2fs_set_bio_crypt_ctx(io->bio, fio->page->mapping->host,
+				       fio->page->index, fio, GFP_NOIO);
 		io->fio = *fio;
 	}
 
@@ -938,11 +977,14 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
 	bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), false);
 	if (!bio)
 		return ERR_PTR(-ENOMEM);
+
+	f2fs_set_bio_crypt_ctx(bio, inode, first_idx, NULL, GFP_NOFS);
+
 	f2fs_target_device(sbi, blkaddr, bio);
 	bio->bi_end_io = f2fs_read_end_io;
 	bio_set_op_attrs(bio, REQ_OP_READ, op_flag);
 
-	if (f2fs_encrypted_file(inode))
+	if (fscrypt_inode_uses_fs_layer_crypto(inode))
 		post_read_steps |= 1 << STEP_DECRYPT;
 	if (f2fs_compressed_file(inode))
 		post_read_steps |= 1 << STEP_DECOMPRESS;
@@ -1972,8 +2014,9 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
 	 * This page will go to BIO.  Do we need to send this
 	 * BIO off first?
 	 */
-	if (bio && !page_is_mergeable(F2FS_I_SB(inode), bio,
-				*last_block_in_bio, block_nr)) {
+	if (bio && (!page_is_mergeable(F2FS_I_SB(inode), bio,
+				       *last_block_in_bio, block_nr) ||
+		    !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL))) {
 submit_and_realloc:
 		__submit_bio(F2FS_I_SB(inode), bio, DATA);
 		bio = NULL;
@@ -2099,8 +2142,9 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 		blkaddr = datablock_addr(dn.inode, dn.node_page,
 						dn.ofs_in_node + i + 1);
 
-		if (bio && !page_is_mergeable(sbi, bio,
-					*last_block_in_bio, blkaddr)) {
+		if (bio && (!page_is_mergeable(sbi, bio,
+					*last_block_in_bio, blkaddr) ||
+		    !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL))) {
 submit_and_realloc:
 			__submit_bio(sbi, bio, DATA);
 			bio = NULL;
@@ -2319,6 +2363,9 @@ int f2fs_encrypt_one_page(struct f2fs_io_info *fio)
 	/* wait for GCed page writeback via META_MAPPING */
 	f2fs_wait_on_block_writeback(inode, fio->old_blkaddr);
 
+	if (fscrypt_inode_uses_inline_crypto(inode))
+		return 0;
+
 retry_encrypt:
 	fio->encrypted_page = fscrypt_encrypt_pagecache_blocks(page,
 					PAGE_SIZE, 0, gfp_flags);
@@ -2492,7 +2539,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
 			f2fs_unlock_op(fio->sbi);
 		err = f2fs_inplace_write_data(fio);
 		if (err) {
-			if (f2fs_encrypted_file(inode))
+			if (fscrypt_inode_uses_fs_layer_crypto(inode))
 				fscrypt_finalize_bounce_page(&fio->encrypted_page);
 			if (PageWriteback(page))
 				end_page_writeback(page);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5355be6b6755..75817f0dc6f8 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -139,6 +139,9 @@ struct f2fs_mount_info {
 	int alloc_mode;			/* segment allocation policy */
 	int fsync_mode;			/* fsync policy */
 	bool test_dummy_encryption;	/* test dummy encryption */
+#ifdef CONFIG_FS_ENCRYPTION
+	bool inlinecrypt;		/* inline encryption enabled */
+#endif
 	block_t unusable_cap;		/* Amount of space allowed to be
 					 * unusable when disabling checkpoint
 					 */
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 65a7a432dfee..fb94ea555c30 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -137,6 +137,7 @@ enum {
 	Opt_alloc,
 	Opt_fsync,
 	Opt_test_dummy_encryption,
+	Opt_inlinecrypt,
 	Opt_checkpoint_disable,
 	Opt_checkpoint_disable_cap,
 	Opt_checkpoint_disable_cap_perc,
@@ -202,6 +203,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_alloc, "alloc_mode=%s"},
 	{Opt_fsync, "fsync_mode=%s"},
 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
+	{Opt_inlinecrypt, "inlinecrypt"},
 	{Opt_checkpoint_disable, "checkpoint=disable"},
 	{Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
 	{Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
@@ -790,6 +792,13 @@ static int parse_options(struct super_block *sb, char *options)
 			f2fs_info(sbi, "Test dummy encryption mode enabled");
 #else
 			f2fs_info(sbi, "Test dummy encryption mount option ignored");
+#endif
+			break;
+		case Opt_inlinecrypt:
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+			sb->s_flags |= SB_INLINE_CRYPT;
+#else
+			f2fs_info(sbi, "inline encryption not supported");
 #endif
 			break;
 		case Opt_checkpoint_disable_cap_perc:
@@ -1538,6 +1547,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 #ifdef CONFIG_FS_ENCRYPTION
 	if (F2FS_OPTION(sbi).test_dummy_encryption)
 		seq_puts(seq, ",test_dummy_encryption");
+	if (sbi->sb->s_flags & SB_INLINE_CRYPT)
+		seq_puts(seq, ",inlinecrypt");
 #endif
 
 	if (F2FS_OPTION(sbi).alloc_mode == ALLOC_MODE_DEFAULT)
@@ -1568,6 +1579,9 @@ static void default_options(struct f2fs_sb_info *sbi)
 	F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_DEFAULT;
 	F2FS_OPTION(sbi).fsync_mode = FSYNC_MODE_POSIX;
 	F2FS_OPTION(sbi).test_dummy_encryption = false;
+#ifdef CONFIG_FS_ENCRYPTION
+	sbi->sb->s_flags &= ~SB_INLINE_CRYPT;
+#endif
 	F2FS_OPTION(sbi).s_resuid = make_kuid(&init_user_ns, F2FS_DEF_RESUID);
 	F2FS_OPTION(sbi).s_resgid = make_kgid(&init_user_ns, F2FS_DEF_RESGID);
 	F2FS_OPTION(sbi).compress_algorithm = COMPRESS_LZO;
@@ -2415,6 +2429,25 @@ static void f2fs_get_ino_and_lblk_bits(struct super_block *sb,
 	*lblk_bits_ret = 8 * sizeof(block_t);
 }
 
+static int f2fs_get_num_devices(struct super_block *sb)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+	if (f2fs_is_multi_device(sbi))
+		return sbi->s_ndevs;
+	return 1;
+}
+
+static void f2fs_get_devices(struct super_block *sb,
+			     struct request_queue **devs)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	int i;
+
+	for (i = 0; i < sbi->s_ndevs; i++)
+		devs[i] = bdev_get_queue(FDEV(i).bdev);
+}
+
 static const struct fscrypt_operations f2fs_cryptops = {
 	.key_prefix		= "f2fs:",
 	.get_context		= f2fs_get_context,
@@ -2424,6 +2457,8 @@ static const struct fscrypt_operations f2fs_cryptops = {
 	.max_namelen		= F2FS_NAME_LEN,
 	.has_stable_inodes	= f2fs_has_stable_inodes,
 	.get_ino_and_lblk_bits	= f2fs_get_ino_and_lblk_bits,
+	.get_num_devices	= f2fs_get_num_devices,
+	.get_devices		= f2fs_get_devices,
 };
 #endif
 
-- 
2.25.0.265.gbab2e86ba0-goog