block: Clean up the code used to generate and verify integrity metadata

Instead of the "operate" parameter we pass in a seed value and a pointer
to a function that can be used to process the integrity metadata. The
generation function is changed to have a return value to fit into this
scheme.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

4 files changed, 94 insertions, 115 deletions

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index cf40837e7710..fe4de033b34c 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -207,49 +207,37 @@ static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
 }
 
 /**
- * bio_integrity_generate_verify - Generate/verify integrity metadata for a bio
+ * bio_integrity_process - Process integrity metadata for a bio
  * @bio:        bio to generate/verify integrity metadata for
- * @operate:    operate number, 1 for generate, 0 for verify
+ * @proc_fn:    Pointer to the relevant processing function
  */
-static int bio_integrity_generate_verify(struct bio *bio, int operate)
+static int bio_integrity_process(struct bio *bio,
+                                 integrity_processing_fn *proc_fn)
 {
         struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-        struct blk_integrity_exchg bix;
+        struct blk_integrity_iter iter;
         struct bio_vec *bv;
         struct bio_integrity_payload *bip = bio_integrity(bio);
-        sector_t seed;
-        unsigned int intervals, ret = 0, i;
+        unsigned int i, ret = 0;
         void *prot_buf = page_address(bip->bip_vec->bv_page) +
                 bip->bip_vec->bv_offset;
 
-        if (operate)
-                seed = bio->bi_iter.bi_sector;
-        else
-                seed = bip->bip_iter.bi_sector;
-
-        bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
-        bix.interval = bi->interval;
+        iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
+        iter.interval = bi->interval;
+        iter.seed = bip_get_seed(bip);
+        iter.prot_buf = prot_buf;
 
         bio_for_each_segment_all(bv, bio, i) {
                 void *kaddr = kmap_atomic(bv->bv_page);
-                bix.data_buf = kaddr + bv->bv_offset;
-                bix.data_size = bv->bv_len;
-                bix.prot_buf = prot_buf;
-                bix.seed = seed;
-
-                if (operate)
-                        bi->generate_fn(&bix);
-                else {
-                        ret = bi->verify_fn(&bix);
-                        if (ret) {
-                                kunmap_atomic(kaddr);
-                                return ret;
-                        }
-                }
 
-                intervals = bv->bv_len / bi->interval;
-                seed += intervals;
-                prot_buf += intervals * bi->tuple_size;
+                iter.data_buf = kaddr + bv->bv_offset;
+                iter.data_size = bv->bv_len;
+
+                ret = proc_fn(&iter);
+                if (ret) {
+                        kunmap_atomic(kaddr);
+                        return ret;
+                }
 
                 kunmap_atomic(kaddr);
         }
@@ -257,20 +245,6 @@ static int bio_integrity_generate_verify(struct bio *bio, int operate)
 }
 
 /**
- * bio_integrity_generate - Generate integrity metadata for a bio
- * @bio:        bio to generate integrity metadata for
- *
- * Description: Generates integrity metadata for a bio by calling the
- * block device's generation callback function.  The bio must have a
- * bip attached with enough room to accommodate the generated
- * integrity metadata.
- */
-static void bio_integrity_generate(struct bio *bio)
-{
-        bio_integrity_generate_verify(bio, 1);
-}
-
-/**
  * bio_integrity_prep - Prepare bio for integrity I/O
  * @bio:        bio to prepare
  *
@@ -321,7 +295,7 @@ int bio_integrity_prep(struct bio *bio)
 
         bip->bip_owns_buf = 1;
         bip->bip_iter.bi_size = len;
-        bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
+        bip_set_seed(bip, bio->bi_iter.bi_sector);
 
         /* Map it */
         offset = offset_in_page(buf);
@@ -357,26 +331,13 @@ int bio_integrity_prep(struct bio *bio)
 
         /* Auto-generate integrity metadata if this is a write */
         if (bio_data_dir(bio) == WRITE)
-                bio_integrity_generate(bio);
+                bio_integrity_process(bio, bi->generate_fn);
 
         return 0;
 }
 EXPORT_SYMBOL(bio_integrity_prep);
 
 /**
- * bio_integrity_verify - Verify integrity metadata for a bio
- * @bio:        bio to verify
- *
- * Description: This function is called to verify the integrity of a
- * bio.  The data in the bio io_vec is compared to the integrity
- * metadata returned by the HBA.
- */
-static int bio_integrity_verify(struct bio *bio)
-{
-        return bio_integrity_generate_verify(bio, 0);
-}
-
-/**
  * bio_integrity_verify_fn - Integrity I/O completion worker
  * @work:       Work struct stored in bio to be verified
  *
@@ -389,9 +350,10 @@ static void bio_integrity_verify_fn(struct work_struct *work)
         struct bio_integrity_payload *bip =
                 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);
         int error;
 
-        error = bio_integrity_verify(bio);
+        error = bio_integrity_process(bio, bi->verify_fn);
 
         /* Restore original bio completion handler */
         bio->bi_end_io = bip->bip_end_io;
diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
index 1600270a46e5..801c41851a01 100644
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -53,42 +53,44 @@ static __u16 sd_dif_ip_fn(void *data, unsigned int len)
  * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
  * 16 bit app tag, 32 bit reference tag.
  */
-static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
+static void sd_dif_type1_generate(struct blk_integrity_iter *iter, csum_fn *fn)
 {
-        void *buf = bix->data_buf;
-        struct sd_dif_tuple *sdt = bix->prot_buf;
-        sector_t seed = bix->seed;
+        void *buf = iter->data_buf;
+        struct sd_dif_tuple *sdt = iter->prot_buf;
+        sector_t seed = iter->seed;
         unsigned int i;
 
-        for (i = 0 ; i < bix->data_size ; i += bix->interval, sdt++) {
-                sdt->guard_tag = fn(buf, bix->interval);
+        for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
+                sdt->guard_tag = fn(buf, iter->interval);
                 sdt->ref_tag = cpu_to_be32(seed & 0xffffffff);
                 sdt->app_tag = 0;
 
-                buf += bix->interval;
+                buf += iter->interval;
                 seed++;
         }
 }
 
-static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix)
+static int sd_dif_type1_generate_crc(struct blk_integrity_iter *iter)
 {
-        sd_dif_type1_generate(bix, sd_dif_crc_fn);
+        sd_dif_type1_generate(iter, sd_dif_crc_fn);
+        return 0;
 }
 
-static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix)
+static int sd_dif_type1_generate_ip(struct blk_integrity_iter *iter)
 {
-        sd_dif_type1_generate(bix, sd_dif_ip_fn);
+        sd_dif_type1_generate(iter, sd_dif_ip_fn);
+        return 0;
 }
 
-static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
+static int sd_dif_type1_verify(struct blk_integrity_iter *iter, csum_fn *fn)
 {
-        void *buf = bix->data_buf;
-        struct sd_dif_tuple *sdt = bix->prot_buf;
-        sector_t seed = bix->seed;
+        void *buf = iter->data_buf;
+        struct sd_dif_tuple *sdt = iter->prot_buf;
+        sector_t seed = iter->seed;
         unsigned int i;
         __u16 csum;
 
-        for (i = 0 ; i < bix->data_size ; i += bix->interval, sdt++) {
+        for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
                 /* Unwritten sectors */
                 if (sdt->app_tag == 0xffff)
                         return 0;
@@ -96,36 +98,36 @@ static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
                 if (be32_to_cpu(sdt->ref_tag) != (seed & 0xffffffff)) {
                         printk(KERN_ERR
                                "%s: ref tag error on sector %lu (rcvd %u)\n",
-                               bix->disk_name, (unsigned long)seed,
+                               iter->disk_name, (unsigned long)seed,
                                be32_to_cpu(sdt->ref_tag));
                         return -EIO;
                 }
 
-                csum = fn(buf, bix->interval);
+                csum = fn(buf, iter->interval);
 
                 if (sdt->guard_tag != csum) {
                         printk(KERN_ERR "%s: guard tag error on sector %lu " \
-                               "(rcvd %04x, data %04x)\n", bix->disk_name,
+                               "(rcvd %04x, data %04x)\n", iter->disk_name,
                                (unsigned long)seed,
                                be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
                         return -EIO;
                 }
 
-                buf += bix->interval;
+                buf += iter->interval;
                 seed++;
         }
 
         return 0;
 }
 
-static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
+static int sd_dif_type1_verify_crc(struct blk_integrity_iter *iter)
 {
-        return sd_dif_type1_verify(bix, sd_dif_crc_fn);
+        return sd_dif_type1_verify(iter, sd_dif_crc_fn);
 }
 
-static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
+static int sd_dif_type1_verify_ip(struct blk_integrity_iter *iter)
 {
-        return sd_dif_type1_verify(bix, sd_dif_ip_fn);
+        return sd_dif_type1_verify(iter, sd_dif_ip_fn);
 }
 
 static struct blk_integrity dif_type1_integrity_crc = {
@@ -149,69 +151,71 @@ static struct blk_integrity dif_type1_integrity_ip = {
  * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
  * tag space.
  */
-static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
+static void sd_dif_type3_generate(struct blk_integrity_iter *iter, csum_fn *fn)
 {
-        void *buf = bix->data_buf;
-        struct sd_dif_tuple *sdt = bix->prot_buf;
+        void *buf = iter->data_buf;
+        struct sd_dif_tuple *sdt = iter->prot_buf;
         unsigned int i;
 
-        for (i = 0 ; i < bix->data_size ; i += bix->interval, sdt++) {
-                sdt->guard_tag = fn(buf, bix->interval);
+        for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
+                sdt->guard_tag = fn(buf, iter->interval);
                 sdt->ref_tag = 0;
                 sdt->app_tag = 0;
 
-                buf += bix->interval;
+                buf += iter->interval;
         }
 }
 
-static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
+static int sd_dif_type3_generate_crc(struct blk_integrity_iter *iter)
 {
-        sd_dif_type3_generate(bix, sd_dif_crc_fn);
+        sd_dif_type3_generate(iter, sd_dif_crc_fn);
+        return 0;
 }
 
-static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
+static int sd_dif_type3_generate_ip(struct blk_integrity_iter *iter)
 {
-        sd_dif_type3_generate(bix, sd_dif_ip_fn);
+        sd_dif_type3_generate(iter, sd_dif_ip_fn);
+        return 0;
 }
 
-static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
+static int sd_dif_type3_verify(struct blk_integrity_iter *iter, csum_fn *fn)
 {
-        void *buf = bix->data_buf;
-        struct sd_dif_tuple *sdt = bix->prot_buf;
-        sector_t seed = bix->seed;
+        void *buf = iter->data_buf;
+        struct sd_dif_tuple *sdt = iter->prot_buf;
+        sector_t seed = iter->seed;
         unsigned int i;
         __u16 csum;
 
-        for (i = 0 ; i < bix->data_size ; i += bix->interval, sdt++) {
+        for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
                 /* Unwritten sectors */
                 if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
                         return 0;
 
-                csum = fn(buf, bix->interval);
+                csum = fn(buf, iter->interval);
 
                 if (sdt->guard_tag != csum) {
                         printk(KERN_ERR "%s: guard tag error on sector %lu " \
-                               "(rcvd %04x, data %04x)\n", bix->disk_name,
+                               "(rcvd %04x, data %04x)\n", iter->disk_name,
                                (unsigned long)seed,
                                be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
                         return -EIO;
                 }
 
-                buf += bix->interval;
+                buf += iter->interval;
                 seed++;
         }
 
         return 0;
 }
 
-static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
+static int sd_dif_type3_verify_crc(struct blk_integrity_iter *iter)
 {
-        return sd_dif_type3_verify(bix, sd_dif_crc_fn);
+        return sd_dif_type3_verify(iter, sd_dif_crc_fn);
 }
 
-static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
+static int sd_dif_type3_verify_ip(struct blk_integrity_iter *iter)
 {
-        return sd_dif_type3_verify(bix, sd_dif_ip_fn);
+        return sd_dif_type3_verify(iter, sd_dif_ip_fn);
 }
 
 static struct blk_integrity dif_type3_integrity_crc = {
@@ -310,6 +314,7 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector,
         phys = hw_sector & 0xffffffff;
 
         __rq_for_each_bio(bio, rq) {
+                struct bio_integrity_payload *bip = bio_integrity(bio);
                 struct bio_vec iv;
                 struct bvec_iter iter;
                 unsigned int j;
@@ -318,9 +323,9 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector,
                 if (bio_flagged(bio, BIO_MAPPED_INTEGRITY))
                         break;
 
-                virt = bio_integrity(bio)->bip_iter.bi_sector & 0xffffffff;
+                virt = bip_get_seed(bip) & 0xffffffff;
 
-                bip_for_each_vec(iv, bio_integrity(bio), iter) {
+                bip_for_each_vec(iv, bip, iter) {
                         sdt = kmap_atomic(iv.bv_page)
                                 + iv.bv_offset;
 
@@ -366,12 +371,13 @@ void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
                 phys >>= 3;
 
         __rq_for_each_bio(bio, scmd->request) {
+                struct bio_integrity_payload *bip = bio_integrity(bio);
                 struct bio_vec iv;
                 struct bvec_iter iter;
 
-                virt = bio_integrity(bio)->bip_iter.bi_sector & 0xffffffff;
+                virt = bip_get_seed(bip) & 0xffffffff;
 
-                bip_for_each_vec(iv, bio_integrity(bio), iter) {
+                bip_for_each_vec(iv, bip, iter) {
                         sdt = kmap_atomic(iv.bv_page)
                                 + iv.bv_offset;
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 448d8c052cb7..3fd36660fd10 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -322,6 +322,18 @@ struct bio_integrity_payload {
         struct bio_vec          *bip_vec;
         struct bio_vec          bip_inline_vecs[0];/* embedded bvec array */
 };
+
+static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
+{
+        return bip->bip_iter.bi_sector;
+}
+
+static inline void bip_set_seed(struct bio_integrity_payload *bip,
+                                sector_t seed)
+{
+        bip->bip_iter.bi_sector = seed;
+}
+
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
 extern void bio_trim(struct bio *bio, int offset, int size);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d364c42dbf17..24c1e055b8a7 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1461,7 +1461,7 @@ static inline uint64_t rq_io_start_time_ns(struct request *req)
 #define INTEGRITY_FLAG_READ     2       /* verify data integrity on read */
 #define INTEGRITY_FLAG_WRITE    4       /* generate data integrity on write */
 
-struct blk_integrity_exchg {
+struct blk_integrity_iter {
         void                    *prot_buf;
         void                    *data_buf;
         sector_t                seed;
@@ -1470,12 +1470,11 @@ struct blk_integrity_exchg {
         const char              *disk_name;
 };
 
-typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
-typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
+typedef int (integrity_processing_fn) (struct blk_integrity_iter *);
 
 struct blk_integrity {
-        integrity_gen_fn        *generate_fn;
-        integrity_vrfy_fn       *verify_fn;
+        integrity_processing_fn *generate_fn;
+        integrity_processing_fn *verify_fn;
 
         unsigned short          flags;
         unsigned short          tuple_size;