bio-integrity: Restore original iterator on verify stage

Currently ->verify_fn not woks at all because at the moment it is called
bio->bi_iter.bi_size == 0, so we do not iterate integrity bvecs at all.

In order to perform verification we need to know original data vector,
with new bvec rewind API this is trivial.

testcase: https://github.com/dmonakhov/xfstests/commit/3c6509eaa83b9c17cd0bc95d73fcdd76e1c54a85

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
[hch: adopted for new status values]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 20 insertions, 6 deletions

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 44c4c52681c2..8df4eb103ba9 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -184,10 +184,11 @@ static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
 /**
  * bio_integrity_process - Process integrity metadata for a bio
  * @bio:        bio to generate/verify integrity metadata for
+ * @proc_iter:  iterator to process
  * @proc_fn:    Pointer to the relevant processing function
  */
 static blk_status_t bio_integrity_process(struct bio *bio,
-                                 integrity_processing_fn *proc_fn)
+                struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
 {
         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
         struct blk_integrity_iter iter;
@@ -200,10 +201,10 @@ static blk_status_t bio_integrity_process(struct bio *bio,
 
         iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
         iter.interval = 1 << bi->interval_exp;
-        iter.seed = bip_get_seed(bip);
+        iter.seed = proc_iter->bi_sector;
         iter.prot_buf = prot_buf;
 
-        bio_for_each_segment(bv, bio, bviter) {
+        __bio_for_each_segment(bv, bio, bviter, *proc_iter) {
                 void *kaddr = kmap_atomic(bv.bv_page);
 
                 iter.data_buf = kaddr + bv.bv_offset;
@@ -332,8 +333,10 @@ bool bio_integrity_prep(struct bio *bio)
         }
 
         /* Auto-generate integrity metadata if this is a write */
-        if (bio_data_dir(bio) == WRITE)
-                bio_integrity_process(bio, bi->profile->generate_fn);
+        if (bio_data_dir(bio) == WRITE) {
+                bio_integrity_process(bio, &bio->bi_iter,
+                                      bi->profile->generate_fn);
+        }
         return true;
 
 err_end_io:
@@ -358,8 +361,19 @@ static void bio_integrity_verify_fn(struct work_struct *work)
                 container_of(work, struct bio_integrity_payload, bip_work);
         struct bio *bio = bip->bip_bio;
         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
+        struct bvec_iter iter = bio->bi_iter;
 
-        bio->bi_status = bio_integrity_process(bio, bi->profile->verify_fn);
+        /*
+         * At the moment verify is called bio's iterator was advanced
+         * during split and completion, we need to rewind iterator to
+         * it's original position.
+         */
+        if (bio_rewind_iter(bio, &iter, iter.bi_done)) {
+                bio->bi_status = bio_integrity_process(bio, &iter,
+                                                       bi->profile->verify_fn);
+        } else {
+                bio->bi_status = BLK_STS_IOERR;
+        }
 
         /* Restore original bio completion handler */
         bio->bi_end_io = bip->bip_end_io;