[PATCH 5/6] fs: Turn decrypt_bh into decrypt_bio

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Pass a bio to decrypt_bio instead of a buffer_head to decrypt_bh.
Another step towards doing decryption per-BIO instead of per-BH.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 fs/buffer.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 627ae1d853c0..f859e0929b7e 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -299,22 +299,24 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
 	return;
 }
 
-struct decrypt_bh_ctx {
+struct decrypt_bio_ctx {
 	struct work_struct work;
-	struct buffer_head *bh;
+	struct bio *bio;
 };
 
-static void decrypt_bh(struct work_struct *work)
+static void decrypt_bio(struct work_struct *work)
 {
-	struct decrypt_bh_ctx *ctx =
-		container_of(work, struct decrypt_bh_ctx, work);
-	struct buffer_head *bh = ctx->bh;
+	struct decrypt_bio_ctx *ctx =
+		container_of(work, struct decrypt_bio_ctx, work);
+	struct bio *bio = ctx->bio;
+	struct buffer_head *bh = bio->bi_private;
 	int err;
 
 	err = fscrypt_decrypt_pagecache_blocks(bh->b_page, bh->b_size,
 					       bh_offset(bh));
 	end_buffer_async_read(bh, err == 0);
 	kfree(ctx);
+	bio_put(bio);
 }
 
 /*
@@ -3093,13 +3095,12 @@ static void end_bio_bh_io_sync(struct bio *bio)
 	/* Decrypt if needed */
 	if ((bio_data_dir(bio) == READ) && uptodate &&
 	    fscrypt_inode_uses_fs_layer_crypto(bh->b_page->mapping->host)) {
-		struct decrypt_bh_ctx *ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
+		struct decrypt_bio_ctx *ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 
 		if (ctx) {
-			INIT_WORK(&ctx->work, decrypt_bh);
-			ctx->bh = bh;
+			INIT_WORK(&ctx->work, decrypt_bio);
+			ctx->bio = bio;
 			fscrypt_enqueue_decrypt_work(&ctx->work);
-			bio_put(bio);
 			return;
 		}
 		uptodate = 0;
-- 
2.28.0