1 files changed, 43 insertions, 11 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index e61a6deea3c0..5adb2042e824 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -85,6 +85,8 @@ MODULE_DEVICE_TABLE(ccw, dasd_eckd_ids);
 
 static struct ccw_driver dasd_eckd_driver; /* see below */
 
+static void *rawpadpage;
+
 #define INIT_CQR_OK 0
 #define INIT_CQR_UNFORMATTED 1
 #define INIT_CQR_ERROR 2
@@ -3237,18 +3239,26 @@ static struct dasd_ccw_req *dasd_raw_build_cp(struct dasd_device *startdev,
         unsigned int seg_len, len_to_track_end;
         unsigned int first_offs;
         unsigned int cidaw, cplength, datasize;
-        sector_t first_trk, last_trk;
+        sector_t first_trk, last_trk, sectors;
+        sector_t start_padding_sectors, end_sector_offset, end_padding_sectors;
         unsigned int pfx_datasize;
 
         /*
          * raw track access needs to be mutiple of 64k and on 64k boundary
+         * For read requests we can fix an incorrect alignment by padding
+         * the request with dummy pages.
          */
-        if ((blk_rq_pos(req) % DASD_RAW_SECTORS_PER_TRACK) != 0) {
-                cqr = ERR_PTR(-EINVAL);
-                goto out;
-        }
-        if (((blk_rq_pos(req) + blk_rq_sectors(req)) %
-             DASD_RAW_SECTORS_PER_TRACK) != 0) {
+        start_padding_sectors = blk_rq_pos(req) % DASD_RAW_SECTORS_PER_TRACK;
+        end_sector_offset = (blk_rq_pos(req) + blk_rq_sectors(req)) %
+                DASD_RAW_SECTORS_PER_TRACK;
+        end_padding_sectors = (DASD_RAW_SECTORS_PER_TRACK - end_sector_offset) %
+                DASD_RAW_SECTORS_PER_TRACK;
+        basedev = block->base;
+        if ((start_padding_sectors || end_padding_sectors) &&
+            (rq_data_dir(req) == WRITE)) {
+                DBF_DEV_EVENT(DBF_ERR, basedev,
+                              "raw write not track aligned (%lu,%lu) req %p",
+                              start_padding_sectors, end_padding_sectors, req);
                 cqr = ERR_PTR(-EINVAL);
                 goto out;
         }
@@ -3258,7 +3268,6 @@ static struct dasd_ccw_req *dasd_raw_build_cp(struct dasd_device *startdev,
                 DASD_RAW_SECTORS_PER_TRACK;
         trkcount = last_trk - first_trk + 1;
         first_offs = 0;
-        basedev = block->base;
 
         if (rq_data_dir(req) == READ)
                 cmd = DASD_ECKD_CCW_READ_TRACK;
@@ -3307,12 +3316,26 @@ static struct dasd_ccw_req *dasd_raw_build_cp(struct dasd_device *startdev,
         }
 
         idaws = (unsigned long *)(cqr->data + pfx_datasize);
-
         len_to_track_end = 0;
-
+        if (start_padding_sectors) {
+                ccw[-1].flags |= CCW_FLAG_CC;
+                ccw->cmd_code = cmd;
+                /* maximum 3390 track size */
+                ccw->count = 57326;
+                /* 64k map to one track */
+                len_to_track_end = 65536 - start_padding_sectors * 512;
+                ccw->cda = (__u32)(addr_t)idaws;
+                ccw->flags |= CCW_FLAG_IDA;
+                ccw->flags |= CCW_FLAG_SLI;
+                ccw++;
+                for (sectors = 0; sectors < start_padding_sectors; sectors += 8)
+                        idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
+        }
         rq_for_each_segment(bv, req, iter) {
                 dst = page_address(bv->bv_page) + bv->bv_offset;
                 seg_len = bv->bv_len;
+                if (cmd == DASD_ECKD_CCW_READ_TRACK)
+                        memset(dst, 0, seg_len);
                 if (!len_to_track_end) {
                         ccw[-1].flags |= CCW_FLAG_CC;
                         ccw->cmd_code = cmd;
@@ -3328,7 +3351,8 @@ static struct dasd_ccw_req *dasd_raw_build_cp(struct dasd_device *startdev,
                 len_to_track_end -= seg_len;
                 idaws = idal_create_words(idaws, dst, seg_len);
         }
-
+        for (sectors = 0; sectors < end_padding_sectors; sectors += 8)
+                idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
         if (blk_noretry_request(req) ||
             block->base->features & DASD_FEATURE_FAILFAST)
                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
@@ -4479,12 +4503,19 @@ dasd_eckd_init(void)
                 kfree(dasd_reserve_req);
                 return -ENOMEM;
         }
+        rawpadpage = (void *)__get_free_page(GFP_KERNEL);
+        if (!rawpadpage) {
+                kfree(path_verification_worker);
+                kfree(dasd_reserve_req);
+                return -ENOMEM;
+        }
         ret = ccw_driver_register(&dasd_eckd_driver);
         if (!ret)
                 wait_for_device_probe();
         else {
                 kfree(path_verification_worker);
                 kfree(dasd_reserve_req);
+                free_page((unsigned long)rawpadpage);
         }
         return ret;
 }
@@ -4495,6 +4526,7 @@ dasd_eckd_cleanup(void)
         ccw_driver_unregister(&dasd_eckd_driver);
         kfree(path_verification_worker);
         kfree(dasd_reserve_req);
+        free_page((unsigned long)rawpadpage);
 }
 
 module_init(dasd_eckd_init);