Use bio_chain instead of rolling our own

* Add lazy init logic to cb format.  Override with --full-init.
 * Make cbd check lazy init aware.
 * Fix up a bunch of size calculation errors.
 * Add pblk validity check in lbd_flush, lbd_read.

dm-compress/lbatview.c

@@ -377,21 +377,21 @@ do_free:
     if (!ret) {
         elem_lelen = __cpu_to_le32(len);
         lbatview_wmem(lv, elem_off, lba_elem_len_bytes(&lv->kparams->params), &elem_lelen);
-        mutex_lock(&lv->kstats->lock);
-        lv->kstats->stats.pblk_used += req_nalloc - old_nalloc;
-        if (old_nalloc == 0) {
-            if (req_nalloc != 0) {
-                ++lv->kstats->stats.lblk_used;
-            }
-        }
-        else {
-            if (req_nalloc == 0) {
-                --lv->kstats->stats.lblk_used;
-            }
-        }
-        mutex_unlock(&lv->kstats->lock);
     }
 
+    mutex_lock(&lv->kstats->lock);
+    if (old_nalloc == 0) {
+        if (cur_nalloc != 0) {
+            ++lv->kstats->stats.lblk_used;
+        }
+    }
+    else {
+        if (cur_nalloc == 0) {
+            --lv->kstats->stats.lblk_used;
+        }
+    }
+    mutex_unlock(&lv->kstats->lock);
+
     mutex_unlock(&lv->lock);
     return ret;
 }

dm-compress/pbat.c

@@ -180,6 +180,9 @@ pbat_alloc(struct pbat* pbat)
     pbat->last_alloc = idx;
     pblk = idx + zone_data_off(&pbat->kparams->params, pbat->zone);
     SetPageDirty(pbat->page);
+    mutex_lock(&pbat->kstats->lock);
+    ++pbat->kstats->stats.pblk_used;
+    mutex_unlock(&pbat->kstats->lock);
 
 out:
     mutex_unlock(&pbat->lock);
@@ -206,6 +209,9 @@ pbat_free(struct pbat* pbat, u64 pblk)
     cbd_bitmap_free(pbat->buf, idx);
     pbat->full = false;
     SetPageDirty(pbat->page);
+    mutex_lock(&pbat->kstats->lock);
+    --pbat->kstats->stats.pblk_used;
+    mutex_unlock(&pbat->kstats->lock);
     mutex_unlock(&pbat->lock);
 
     return 0;

dm-compress/util.c

@@ -230,53 +230,21 @@ pblk_write(struct compress_params* kparams,
     submit_bio(bio);
 }
 
-struct pblk_iov
-{
-    struct compress_params*     kparams;
-    atomic_t                    remain;
-};
-
-void
-pblk_writev_endio(struct bio* bio)
-{
-    struct pblk_iov* iov = bio->bi_private;
-    struct compress_params* kparams = iov->kparams;
-    struct page* page = bio->bi_io_vec[0].bv_page;
-
-    if (bio->bi_status != BLK_STS_OK) {
-        printk(KERN_ERR "%s: I/O error\n", __func__);
-        kparams->params.flags |= CBD_FLAG_ERROR;
-        SetPageError(page);
-    }
-    if (atomic_dec_and_test(&iov->remain)) {
-        ClearPageDirty(page);
-        unlock_page(page);
-        kfree(iov);
-    }
-    bio_put(bio);
-}
-
 void
 pblk_writev(struct compress_params* kparams,
         u64* pblkv, u32 count, struct page* page)
 {
     u32 pblk_len = pblk_size(&kparams->params);
-    struct pblk_iov* iov;
     u32 idx;
     u32 page_off;
     u32 nr_bio;
     u64 pblk;
     u32 iov_nr_pblk;
+    struct bio* parent_bio;
     struct bio* bio;
 
     BUG_ON(pblk_len * count > PAGE_SIZE);
-    iov = kmalloc(sizeof(struct pblk_iov), GFP_KERNEL);
-    if (!iov) {
-        printk(KERN_ERR "%s: out of memory\n", __func__);
-        goto err;
-    }
-    iov->kparams = kparams;
-    atomic_set(&iov->remain, count);
+    parent_bio = NULL;
     idx = 0;
     page_off = 0;
     nr_bio = 0;
@@ -292,25 +260,29 @@ pblk_writev(struct compress_params* kparams,
             pblk_len, pblk, iov_nr_pblk, page, page_off);
         if (!bio) {
             printk(KERN_ERR "%s: out of memory\n", __func__);
-            goto err_free;
+            goto err;
+        }
+        if (!parent_bio) {
+            bio->bi_end_io = pblk_write_endio;
+            bio->bi_private = kparams;
+            parent_bio = bio;
+        }
+        else {
+            bio_chain(bio, parent_bio);
+            parent_bio = bio;
         }
-        ++nr_bio;
-        bio->bi_end_io = pblk_writev_endio;
-        bio->bi_private = iov;
-        submit_bio(bio);
         page_off += pblk_len * iov_nr_pblk;
-    }
-    if (atomic_sub_and_test(count - nr_bio, &iov->remain)) {
-        ClearPageDirty(page);
-        unlock_page(page);
-        kfree(iov);
+        submit_bio(bio);
     }
 
     return;
 
-err_free:
-    kfree(iov);
 err:
+    while (parent_bio) {
+        bio = parent_bio;
+        parent_bio = bio->bi_private;
+        bio_put(bio);
+    }
     kparams->params.flags |= CBD_FLAG_ERROR;
     SetPageError(page);
     unlock_page(page);

libcbd/open.c

@@ -26,7 +26,7 @@ device_logical_sectors(const char* dev)
     }
     lblk_total = header.params.lblk_per_zone * header.params.nr_zones;
 
-    return lblk_total >> (header.params.lblk_shift + header.params.pblk_shift);
+    return lblk_total << (header.params.lblk_shift + header.params.pblk_shift);
 }
 
 int