f2fs crypto: add encryption support in read/write paths

This patch adds encryption support in read and write paths.

Note that, in f2fs, we need to consider cleaning operation.
In cleaning procedure, we must avoid encrypting and decrypting written blocks.
So, this patch implements move_encrypted_block().

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 20 insertions, 4 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 989c0bf48431..2c40ce132895 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -219,6 +219,7 @@ void commit_inmem_pages(struct inode *inode, bool abort)
 		.sbi = sbi,
 		.type = DATA,
 		.rw = WRITE_SYNC | REQ_PRIO,
+		.encrypted_page = NULL,
 	};
 
 	/*
@@ -1231,6 +1232,7 @@ void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
 		.rw = WRITE_SYNC | REQ_META | REQ_PRIO,
 		.blk_addr = page->index,
 		.page = page,
+		.encrypted_page = NULL,
 	};
 
 	set_page_writeback(page);
@@ -1330,20 +1332,34 @@ static inline bool is_merged_page(struct f2fs_sb_info *sbi,
 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
 	struct f2fs_bio_info *io = &sbi->write_io[btype];
 	struct bio_vec *bvec;
+	struct page *target;
 	int i;
 
 	down_read(&io->io_rwsem);
-	if (!io->bio)
-		goto out;
+	if (!io->bio) {
+		up_read(&io->io_rwsem);
+		return false;
+	}
 
 	bio_for_each_segment_all(bvec, io->bio, i) {
-		if (page == bvec->bv_page) {
+
+		if (bvec->bv_page->mapping) {
+			target = bvec->bv_page;
+		} else {
+			struct f2fs_crypto_ctx *ctx;
+
+			/* encrypted page */
+			ctx = (struct f2fs_crypto_ctx *)page_private(
+								bvec->bv_page);
+			target = ctx->control_page;
+		}
+
+		if (page == target) {
 			up_read(&io->io_rwsem);
 			return true;
 		}
 	}
 
-out:
 	up_read(&io->io_rwsem);
 	return false;
 }