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Date: Mon, 15 Aug 2022 16:50:52 -0700
From: Eric Biggers <ebiggers@...nel.org>
To: linux-fscrypt@...r.kernel.org
Cc: linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net,
Matthew Wilcox <willy@...radead.org>
Subject: [PATCH v2 2/2] fsverity: stop using PG_error to track error status
From: Eric Biggers <ebiggers@...gle.com>
As a step towards freeing the PG_error flag for other uses, change ext4
and f2fs to stop using PG_error to track verity errors. Instead, if a
verity 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.
f2fs supports compression, which makes the f2fs changes a bit more
complicated than desired, but the basic premise still works.
Signed-off-by: Eric Biggers <ebiggers@...gle.com>
---
fs/ext4/readpage.c | 8 ++----
fs/f2fs/compress.c | 64 ++++++++++++++++++++++------------------------
fs/f2fs/data.c | 52 ++++++++++++++++++++-----------------
fs/verity/verify.c | 12 ++++-----
4 files changed, 68 insertions(+), 68 deletions(-)
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index 5ce4706f68a7c6..e604ea4e102b71 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -75,14 +75,10 @@ static void __read_end_io(struct bio *bio)
bio_for_each_segment_all(bv, bio, iter_all) {
page = bv->bv_page;
- /* PG_error was set if any post_read step failed */
- if (bio->bi_status || PageError(page)) {
+ if (bio->bi_status)
ClearPageUptodate(page);
- /* will re-read again later */
- ClearPageError(page);
- } else {
+ else
SetPageUptodate(page);
- }
unlock_page(page);
}
if (bio->bi_private)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 70e97075e535e5..f54fb3bb74197a 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1715,50 +1715,27 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task)
}
}
-/*
- * Update and unlock the cluster's pagecache pages, and release the reference to
- * the decompress_io_ctx that was being held for I/O completion.
- */
-static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed,
- bool in_task)
+static void f2fs_verify_cluster(struct work_struct *work)
{
+ struct decompress_io_ctx *dic =
+ container_of(work, struct decompress_io_ctx, verity_work);
int i;
+ /* Verify, update, and unlock the decompressed pages. */
for (i = 0; i < dic->cluster_size; i++) {
struct page *rpage = dic->rpages[i];
if (!rpage)
continue;
- /* PG_error was set if verity failed. */
- if (failed || PageError(rpage)) {
- ClearPageUptodate(rpage);
- /* will re-read again later */
- ClearPageError(rpage);
- } else {
+ if (fsverity_verify_page(rpage))
SetPageUptodate(rpage);
- }
+ else
+ ClearPageUptodate(rpage);
unlock_page(rpage);
}
- f2fs_put_dic(dic, in_task);
-}
-
-static void f2fs_verify_cluster(struct work_struct *work)
-{
- struct decompress_io_ctx *dic =
- container_of(work, struct decompress_io_ctx, verity_work);
- int i;
-
- /* Verify the cluster's decompressed pages with fs-verity. */
- for (i = 0; i < dic->cluster_size; i++) {
- struct page *rpage = dic->rpages[i];
-
- if (rpage && !fsverity_verify_page(rpage))
- SetPageError(rpage);
- }
-
- __f2fs_decompress_end_io(dic, false, true);
+ f2fs_put_dic(dic, true);
}
/*
@@ -1768,6 +1745,8 @@ static void f2fs_verify_cluster(struct work_struct *work)
void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed,
bool in_task)
{
+ int i;
+
if (!failed && dic->need_verity) {
/*
* Note that to avoid deadlocks, the verity work can't be done
@@ -1777,9 +1756,28 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed,
*/
INIT_WORK(&dic->verity_work, f2fs_verify_cluster);
fsverity_enqueue_verify_work(&dic->verity_work);
- } else {
- __f2fs_decompress_end_io(dic, failed, in_task);
+ return;
+ }
+
+ /* Update and unlock the cluster's pagecache pages. */
+ for (i = 0; i < dic->cluster_size; i++) {
+ struct page *rpage = dic->rpages[i];
+
+ if (!rpage)
+ continue;
+
+ if (failed)
+ ClearPageUptodate(rpage);
+ else
+ SetPageUptodate(rpage);
+ unlock_page(rpage);
}
+
+ /*
+ * Release the reference to the decompress_io_ctx that was being held
+ * for I/O completion.
+ */
+ f2fs_put_dic(dic, in_task);
}
/*
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 93cc2ec51c2aeb..34af260975a2e6 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -119,34 +119,41 @@ struct bio_post_read_ctx {
block_t fs_blkaddr;
};
-static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
+/*
+ * Update and unlock a bio's pages, and free the bio.
+ *
+ * This marks pages up-to-date only if there was no error in the bio (I/O error,
+ * decryption error, or verity error), as indicated by bio->bi_status.
+ *
+ * "Compressed pages" (pagecache pages backed by a compressed cluster on-disk)
+ * aren't marked up-to-date here, as decompression is done on a per-compression-
+ * cluster basis rather than a per-bio basis. Instead, we only must do two
+ * things for each compressed page here: call f2fs_end_read_compressed_page()
+ * with failed=true if an error occurred before it would have normally gotten
+ * called (i.e., I/O error or decryption error, but *not* verity error), and
+ * release the bio's reference to the decompress_io_ctx of the page's cluster.
+ */
+static void f2fs_finish_read_bio(struct bio *bio, bool in_task,
+ bool fail_compressed)
{
struct bio_vec *bv;
struct bvec_iter_all iter_all;
- /*
- * Update and unlock the bio's pagecache pages, and put the
- * decompression context for any compressed pages.
- */
bio_for_each_segment_all(bv, bio, iter_all) {
struct page *page = bv->bv_page;
if (f2fs_is_compressed_page(page)) {
- if (bio->bi_status)
+ if (fail_compressed)
f2fs_end_read_compressed_page(page, true, 0,
in_task);
f2fs_put_page_dic(page, in_task);
continue;
}
- /* PG_error was set if verity failed. */
- if (bio->bi_status || PageError(page)) {
+ if (bio->bi_status)
ClearPageUptodate(page);
- /* will re-read again later */
- ClearPageError(page);
- } else {
+ else
SetPageUptodate(page);
- }
dec_page_count(F2FS_P_SB(page), __read_io_type(page));
unlock_page(page);
}
@@ -185,14 +192,17 @@ static void f2fs_verify_bio(struct work_struct *work)
struct page *page = bv->bv_page;
if (!f2fs_is_compressed_page(page) &&
- !fsverity_verify_page(page))
- SetPageError(page);
+ !fsverity_verify_page(page)) {
+ bio->bi_status = BLK_STS_IOERR;
+ break;
+ }
}
} else {
fsverity_verify_bio(bio);
}
- f2fs_finish_read_bio(bio, true);
+ f2fs_finish_read_bio(bio, true /* in_task */,
+ false /* fail_compressed */);
}
/*
@@ -212,7 +222,7 @@ static void f2fs_verify_and_finish_bio(struct bio *bio, bool in_task)
INIT_WORK(&ctx->work, f2fs_verify_bio);
fsverity_enqueue_verify_work(&ctx->work);
} else {
- f2fs_finish_read_bio(bio, in_task);
+ f2fs_finish_read_bio(bio, in_task, false /* fail_compressed */);
}
}
@@ -261,7 +271,8 @@ static void f2fs_post_read_work(struct work_struct *work)
struct bio *bio = ctx->bio;
if ((ctx->enabled_steps & STEP_DECRYPT) && !fscrypt_decrypt_bio(bio)) {
- f2fs_finish_read_bio(bio, true);
+ f2fs_finish_read_bio(bio, true /* in_task */,
+ true /* fail_compressed */);
return;
}
@@ -286,7 +297,7 @@ static void f2fs_read_end_io(struct bio *bio)
}
if (bio->bi_status) {
- f2fs_finish_read_bio(bio, intask);
+ f2fs_finish_read_bio(bio, intask, true /* fail_compressed */);
return;
}
@@ -1083,7 +1094,6 @@ static int f2fs_submit_page_read(struct inode *inode, struct page *page,
bio_put(bio);
return -EFAULT;
}
- ClearPageError(page);
inc_page_count(sbi, F2FS_RD_DATA);
f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
__submit_bio(sbi, bio, DATA);
@@ -2125,7 +2135,6 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA);
f2fs_update_iostat(F2FS_I_SB(inode), FS_DATA_READ_IO, F2FS_BLKSIZE);
- ClearPageError(page);
*last_block_in_bio = block_nr;
goto out;
out:
@@ -2274,7 +2283,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
inc_page_count(sbi, F2FS_RD_DATA);
f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
f2fs_update_iostat(sbi, FS_CDATA_READ_IO, F2FS_BLKSIZE);
- ClearPageError(page);
*last_block_in_bio = blkaddr;
}
@@ -2291,7 +2299,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
for (i = 0; i < cc->cluster_size; i++) {
if (cc->rpages[i]) {
ClearPageUptodate(cc->rpages[i]);
- ClearPageError(cc->rpages[i]);
unlock_page(cc->rpages[i]);
}
}
@@ -2388,7 +2395,6 @@ static int f2fs_mpage_readpages(struct inode *inode,
#ifdef CONFIG_F2FS_FS_COMPRESSION
set_error_page:
#endif
- SetPageError(page);
zero_user_segment(page, 0, PAGE_SIZE);
unlock_page(page);
}
diff --git a/fs/verity/verify.c b/fs/verity/verify.c
index 14e2fb49cff561..556dfbd4698dea 100644
--- a/fs/verity/verify.c
+++ b/fs/verity/verify.c
@@ -210,9 +210,8 @@ EXPORT_SYMBOL_GPL(fsverity_verify_page);
* @bio: the bio to verify
*
* Verify a set of pages that have just been read from a verity file. The pages
- * must be pagecache pages that are still locked and not yet uptodate. Pages
- * that fail verification are set to the Error state. Verification is skipped
- * for pages already in the Error state, e.g. due to fscrypt decryption failure.
+ * must be pagecache pages that are still locked and not yet uptodate. If a
+ * page fails verification, then bio->bi_status is set to an error status.
*
* This is a helper function for use by the ->readahead() method of filesystems
* that issue bios to read data directly into the page cache. Filesystems that
@@ -254,9 +253,10 @@ void fsverity_verify_bio(struct bio *bio)
unsigned long level0_ra_pages =
min(max_ra_pages, params->level0_blocks - level0_index);
- if (!PageError(page) &&
- !verify_page(inode, vi, req, page, level0_ra_pages))
- SetPageError(page);
+ if (!verify_page(inode, vi, req, page, level0_ra_pages)) {
+ bio->bi_status = BLK_STS_IOERR;
+ break;
+ }
}
fsverity_free_hash_request(params->hash_alg, req);
--
2.37.1
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