diff mbox series

[1/2] fscrypt: stop using PG_error to track error status

Message ID 20220627065050.274716-2-ebiggers@kernel.org (mailing list archive)
State Superseded
Headers show
Series ext4, f2fs: stop using PG_error for fscrypt and fsverity | expand

Commit Message

Eric Biggers June 27, 2022, 6:50 a.m. UTC 
From: Eric Biggers <ebiggers@google.com>

As a step towards freeing the PG_error flag for other uses, change ext4
and f2fs to stop using PG_error to track decryption errors.  Instead, if
a decryption error occurs, just mark the whole bio as failed.  The
coarser granularity isn't really a problem since it isn't any worse than
what the block layer provides, and errors from a multi-page readahead
aren't reported to applications unless a single-page read fails too.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/crypto/bio.c         | 16 ++++++++++------
 fs/ext4/readpage.c      |  8 +++++---
 fs/f2fs/data.c          | 17 +++++++++--------
 include/linux/fscrypt.h |  5 +++--
 4 files changed, 27 insertions(+), 19 deletions(-)
diff mbox series

Patch

diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index 2217fe5ece6f9..1b4403136d05c 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -25,21 +25,25 @@ 
  * then this function isn't applicable.  This function may sleep, so it must be
  * called from a workqueue rather than from the bio's bi_end_io callback.
  *
- * This function sets PG_error on any pages that contain any blocks that failed
- * to be decrypted.  The filesystem must not mark such pages uptodate.
+ * Return: %true on success; %false on failure.  On failure, bio->bi_status is
+ *	   also set to an error status.
  */
-void fscrypt_decrypt_bio(struct bio *bio)
+bool fscrypt_decrypt_bio(struct bio *bio)
 {
 	struct bio_vec *bv;
 	struct bvec_iter_all iter_all;
 
 	bio_for_each_segment_all(bv, bio, iter_all) {
 		struct page *page = bv->bv_page;
-		int ret = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
+		int err = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
 							   bv->bv_offset);
-		if (ret)
-			SetPageError(page);
+
+		if (err) {
+			bio->bi_status = errno_to_blk_status(err);
+			return false;
+		}
 	}
+	return true;
 }
 EXPORT_SYMBOL(fscrypt_decrypt_bio);
 
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index e02a5f14e0211..5ce4706f68a7c 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -96,10 +96,12 @@  static void decrypt_work(struct work_struct *work)
 {
 	struct bio_post_read_ctx *ctx =
 		container_of(work, struct bio_post_read_ctx, work);
+	struct bio *bio = ctx->bio;
 
-	fscrypt_decrypt_bio(ctx->bio);
-
-	bio_post_read_processing(ctx);
+	if (fscrypt_decrypt_bio(bio))
+		bio_post_read_processing(ctx);
+	else
+		__read_end_io(bio);
 }
 
 static void verity_work(struct work_struct *work)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 7fcbcf9797372..47065f17d579c 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -138,7 +138,7 @@  static void f2fs_finish_read_bio(struct bio *bio)
 			continue;
 		}
 
-		/* PG_error was set if decryption or verity failed. */
+		/* PG_error was set if verity failed. */
 		if (bio->bi_status || PageError(page)) {
 			ClearPageUptodate(page);
 			/* will re-read again later */
@@ -184,7 +184,7 @@  static void f2fs_verify_bio(struct work_struct *work)
 			struct page *page = bv->bv_page;
 
 			if (!f2fs_is_compressed_page(page) &&
-			    !PageError(page) && !fsverity_verify_page(page))
+			    !fsverity_verify_page(page))
 				SetPageError(page);
 		}
 	} else {
@@ -234,10 +234,8 @@  static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx)
 	bio_for_each_segment_all(bv, ctx->bio, iter_all) {
 		struct page *page = bv->bv_page;
 
-		/* PG_error was set if decryption failed. */
 		if (f2fs_is_compressed_page(page))
-			f2fs_end_read_compressed_page(page, PageError(page),
-						blkaddr);
+			f2fs_end_read_compressed_page(page, false, blkaddr);
 		else
 			all_compressed = false;
 
@@ -257,14 +255,17 @@  static void f2fs_post_read_work(struct work_struct *work)
 {
 	struct bio_post_read_ctx *ctx =
 		container_of(work, struct bio_post_read_ctx, work);
+	struct bio *bio = ctx->bio;
 
-	if (ctx->enabled_steps & STEP_DECRYPT)
-		fscrypt_decrypt_bio(ctx->bio);
+	if ((ctx->enabled_steps & STEP_DECRYPT) && !fscrypt_decrypt_bio(bio)) {
+		f2fs_finish_read_bio(bio);
+		return;
+	}
 
 	if (ctx->enabled_steps & STEP_DECOMPRESS)
 		f2fs_handle_step_decompress(ctx);
 
-	f2fs_verify_and_finish_bio(ctx->bio);
+	f2fs_verify_and_finish_bio(bio);
 }
 
 static void f2fs_read_end_io(struct bio *bio)
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index e60d57c99cb6f..e9a3a51f29632 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -348,7 +348,7 @@  u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
 int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags);
 
 /* bio.c */
-void fscrypt_decrypt_bio(struct bio *bio);
+bool fscrypt_decrypt_bio(struct bio *bio);
 int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 			  sector_t pblk, unsigned int len);
 
@@ -641,8 +641,9 @@  static inline int fscrypt_d_revalidate(struct dentry *dentry,
 }
 
 /* bio.c */
-static inline void fscrypt_decrypt_bio(struct bio *bio)
+static inline bool fscrypt_decrypt_bio(struct bio *bio)
 {
+	return true;
 }
 
 static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,