diff mbox series

[v4,06/21] parallels: Move host clusters allocation to a separate function

Message ID 20231228101232.372142-7-alexander.ivanov@virtuozzo.com (mailing list archive)
State New, archived
Headers show
Series parallels: Add full dirty bitmap support | expand

Commit Message

Alexander Ivanov Dec. 28, 2023, 10:12 a.m. UTC
For parallels images extensions we need to allocate host clusters
without any connection to BAT. Move host clusters allocation code to
parallels_allocate_host_clusters().

This function can be called not only from coroutines so all the
*_co_* functions were replaced by corresponding wrappers.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
 block/parallels.c | 128 ++++++++++++++++++++++++----------------------
 block/parallels.h |   3 ++
 2 files changed, 71 insertions(+), 60 deletions(-)

Comments

Denis V. Lunev Jan. 16, 2024, 2:19 p.m. UTC | #1
On 12/28/23 11:12, Alexander Ivanov wrote:
> For parallels images extensions we need to allocate host clusters
> without any connection to BAT. Move host clusters allocation code to
> parallels_allocate_host_clusters().
>
> This function can be called not only from coroutines so all the
> *_co_* functions were replaced by corresponding wrappers.
>
> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
> ---
>   block/parallels.c | 128 ++++++++++++++++++++++++----------------------
>   block/parallels.h |   3 ++
>   2 files changed, 71 insertions(+), 60 deletions(-)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 13726fb3d5..658902ae51 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -268,58 +268,31 @@ static void parallels_free_used_bitmap(BlockDriverState *bs)
>       s->used_bmap = NULL;
>   }
>   
> -static int64_t coroutine_fn GRAPH_RDLOCK
> -allocate_clusters(BlockDriverState *bs, int64_t sector_num,
> -                  int nb_sectors, int *pnum)
> +int64_t GRAPH_RDLOCK parallels_allocate_host_clusters(BlockDriverState *bs,
> +                                                      int64_t *clusters)
>   {
> -    int ret = 0;
>       BDRVParallelsState *s = bs->opaque;
> -    int64_t i, pos, idx, to_allocate, first_free, host_off;
> -
> -    pos = block_status(s, sector_num, nb_sectors, pnum);
> -    if (pos > 0) {
> -        return pos;
> -    }
> -
> -    idx = sector_num / s->tracks;
> -    to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
> -
> -    /*
> -     * This function is called only by parallels_co_writev(), which will never
> -     * pass a sector_num at or beyond the end of the image (because the block
> -     * layer never passes such a sector_num to that function). Therefore, idx
> -     * is always below s->bat_size.
> -     * block_status() will limit *pnum so that sector_num + *pnum will not
> -     * exceed the image end. Therefore, idx + to_allocate cannot exceed
> -     * s->bat_size.
> -     * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
> -     * will always fit into a uint32_t.
> -     */
> -    assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
> +    int64_t first_free, next_used, host_off, prealloc_clusters;
> +    int64_t bytes, prealloc_bytes;
> +    uint32_t new_usedsize;
> +    int ret = 0;
>   
>       first_free = find_first_zero_bit(s->used_bmap, s->used_bmap_size);
>       if (first_free == s->used_bmap_size) {
> -        uint32_t new_usedsize;
> -        int64_t bytes = to_allocate * s->cluster_size;
> -        bytes += s->prealloc_size * BDRV_SECTOR_SIZE;
> -
>           host_off = s->data_end * BDRV_SECTOR_SIZE;
> +        prealloc_clusters = *clusters + s->prealloc_size / s->tracks;
> +        bytes = *clusters * s->cluster_size;
> +        prealloc_bytes = prealloc_clusters * s->cluster_size;
>   
> -        /*
> -         * We require the expanded size to read back as zero. If the
> -         * user permitted truncation, we try that; but if it fails, we
> -         * force the safer-but-slower fallocate.
> -         */
This comment seems useful. I'd better keep it as is.

For now (if we will not have a re-submission, I'll have
the comment back in the code). If the code will be
resubmitted, please add it back.

>           if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
> -            ret = bdrv_co_truncate(bs->file, host_off + bytes,
> -                                   false, PREALLOC_MODE_OFF,
> -                                   BDRV_REQ_ZERO_WRITE, NULL);
> +            ret = bdrv_truncate(bs->file, host_off + prealloc_bytes, false,
> +                                PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL);
>               if (ret == -ENOTSUP) {
>                   s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
>               }
>           }
>           if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
> -            ret = bdrv_co_pwrite_zeroes(bs->file, host_off, bytes, 0);
> +            ret = bdrv_pwrite_zeroes(bs->file, host_off, prealloc_bytes, 0);
>           }
>           if (ret < 0) {
>               return ret;
> @@ -329,15 +302,15 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
>           s->used_bmap = bitmap_zero_extend(s->used_bmap, s->used_bmap_size,
>                                             new_usedsize);
>           s->used_bmap_size = new_usedsize;
> +        if (host_off + bytes > s->data_end * BDRV_SECTOR_SIZE) {
> +            s->data_end = (host_off + bytes) / BDRV_SECTOR_SIZE;
> +        }
>       } else {
> -        int64_t next_used;
>           next_used = find_next_bit(s->used_bmap, s->used_bmap_size, first_free);
>   
>           /* Not enough continuous clusters in the middle, adjust the size */
> -        if (next_used - first_free < to_allocate) {
> -            to_allocate = next_used - first_free;
> -            *pnum = (idx + to_allocate) * s->tracks - sector_num;
> -        }
> +        *clusters = MIN(*clusters, next_used - first_free);
> +        bytes = *clusters * s->cluster_size;
>   
>           host_off = s->data_start * BDRV_SECTOR_SIZE;
>           host_off += first_free * s->cluster_size;
> @@ -349,14 +322,59 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
>            */
>           if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE &&
>                   host_off < s->data_end * BDRV_SECTOR_SIZE) {
> -            ret = bdrv_co_pwrite_zeroes(bs->file, host_off,
> -                                        s->cluster_size * to_allocate, 0);
> +            ret = bdrv_pwrite_zeroes(bs->file, host_off, bytes, 0);
>               if (ret < 0) {
>                   return ret;
>               }
>           }
>       }
>   
> +    ret = parallels_mark_used(bs, s->used_bmap, s->used_bmap_size,
> +                              host_off, *clusters);
> +    if (ret < 0) {
> +        /* Image consistency is broken. Alarm! */
> +        return ret;
> +    }
> +
> +    return host_off;
> +}
> +
> +static int64_t coroutine_fn GRAPH_RDLOCK
> +allocate_clusters(BlockDriverState *bs, int64_t sector_num,
> +                  int nb_sectors, int *pnum)
> +{
> +    int ret = 0;
> +    BDRVParallelsState *s = bs->opaque;
> +    int64_t i, pos, idx, to_allocate, host_off;
> +
> +    pos = block_status(s, sector_num, nb_sectors, pnum);
> +    if (pos > 0) {
> +        return pos;
> +    }
> +
> +    idx = sector_num / s->tracks;
> +    to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
> +
> +    /*
> +     * This function is called only by parallels_co_writev(), which will never
> +     * pass a sector_num at or beyond the end of the image (because the block
> +     * layer never passes such a sector_num to that function). Therefore, idx
> +     * is always below s->bat_size.
> +     * block_status() will limit *pnum so that sector_num + *pnum will not
> +     * exceed the image end. Therefore, idx + to_allocate cannot exceed
> +     * s->bat_size.
> +     * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
> +     * will always fit into a uint32_t.
> +     */
> +    assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
> +
> +    host_off = parallels_allocate_host_clusters(bs, &to_allocate);
> +    if (host_off < 0) {
> +        return host_off;
> +    }
> +
> +    *pnum = MIN(*pnum, (idx + to_allocate) * s->tracks - sector_num);
> +
>       /*
>        * Try to read from backing to fill empty clusters
>        * FIXME: 1. previous write_zeroes may be redundant
> @@ -373,33 +391,23 @@ allocate_clusters(BlockDriverState *bs, int64_t sector_num,
>   
>           ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
>                               nb_cow_bytes, buf, 0);
> -        if (ret < 0) {
> -            qemu_vfree(buf);
> -            return ret;
> +        if (ret == 0) {
> +            ret = bdrv_co_pwrite(bs->file, host_off, nb_cow_bytes, buf, 0);
>           }
>   
> -        ret = bdrv_co_pwrite(bs->file, s->data_end * BDRV_SECTOR_SIZE,
> -                             nb_cow_bytes, buf, 0);
>           qemu_vfree(buf);
>           if (ret < 0) {
> +            parallels_mark_unused(bs, s->used_bmap, s->used_bmap_size,
> +                                  host_off, to_allocate);
>               return ret;
>           }
>       }
>   
> -    ret = parallels_mark_used(bs, s->used_bmap, s->used_bmap_size,
> -                              host_off, to_allocate);
> -    if (ret < 0) {
> -        /* Image consistency is broken. Alarm! */
> -        return ret;
> -    }
>       for (i = 0; i < to_allocate; i++) {
>           parallels_set_bat_entry(s, idx + i,
>                   host_off / BDRV_SECTOR_SIZE / s->off_multiplier);
>           host_off += s->cluster_size;
>       }
> -    if (host_off > s->data_end * BDRV_SECTOR_SIZE) {
> -        s->data_end = host_off / BDRV_SECTOR_SIZE;
> -    }
>   
>       return bat2sect(s, idx) + sector_num % s->tracks;
>   }
> diff --git a/block/parallels.h b/block/parallels.h
> index 02b857b4a4..493c89e976 100644
> --- a/block/parallels.h
> +++ b/block/parallels.h
> @@ -95,6 +95,9 @@ int parallels_mark_used(BlockDriverState *bs, unsigned long *bitmap,
>   int parallels_mark_unused(BlockDriverState *bs, unsigned long *bitmap,
>                             uint32_t bitmap_size, int64_t off, uint32_t count);
>   
> +int64_t GRAPH_RDLOCK parallels_allocate_host_clusters(BlockDriverState *bs,
> +                                                      int64_t *clusters);
> +
>   int GRAPH_RDLOCK
>   parallels_read_format_extension(BlockDriverState *bs, int64_t ext_off,
>                                   Error **errp);
There is a difference in between what we have had before
this patch and after. On a error originally we have had
data_end unchanged, now it points to a wrong location.

May be this would be mitigated later, but I'd prefer
to have data_end updated in mark_unused. That would make
a lot of sense.

Anyway, with data_end dropped at the end of the series,
this would not worth efforts. Thus this is fine.

With a note about comment,

Reviewed-by: Denis V. Lunev <den@openvz.org>
diff mbox series

Patch

diff --git a/block/parallels.c b/block/parallels.c
index 13726fb3d5..658902ae51 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -268,58 +268,31 @@  static void parallels_free_used_bitmap(BlockDriverState *bs)
     s->used_bmap = NULL;
 }
 
-static int64_t coroutine_fn GRAPH_RDLOCK
-allocate_clusters(BlockDriverState *bs, int64_t sector_num,
-                  int nb_sectors, int *pnum)
+int64_t GRAPH_RDLOCK parallels_allocate_host_clusters(BlockDriverState *bs,
+                                                      int64_t *clusters)
 {
-    int ret = 0;
     BDRVParallelsState *s = bs->opaque;
-    int64_t i, pos, idx, to_allocate, first_free, host_off;
-
-    pos = block_status(s, sector_num, nb_sectors, pnum);
-    if (pos > 0) {
-        return pos;
-    }
-
-    idx = sector_num / s->tracks;
-    to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
-
-    /*
-     * This function is called only by parallels_co_writev(), which will never
-     * pass a sector_num at or beyond the end of the image (because the block
-     * layer never passes such a sector_num to that function). Therefore, idx
-     * is always below s->bat_size.
-     * block_status() will limit *pnum so that sector_num + *pnum will not
-     * exceed the image end. Therefore, idx + to_allocate cannot exceed
-     * s->bat_size.
-     * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
-     * will always fit into a uint32_t.
-     */
-    assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
+    int64_t first_free, next_used, host_off, prealloc_clusters;
+    int64_t bytes, prealloc_bytes;
+    uint32_t new_usedsize;
+    int ret = 0;
 
     first_free = find_first_zero_bit(s->used_bmap, s->used_bmap_size);
     if (first_free == s->used_bmap_size) {
-        uint32_t new_usedsize;
-        int64_t bytes = to_allocate * s->cluster_size;
-        bytes += s->prealloc_size * BDRV_SECTOR_SIZE;
-
         host_off = s->data_end * BDRV_SECTOR_SIZE;
+        prealloc_clusters = *clusters + s->prealloc_size / s->tracks;
+        bytes = *clusters * s->cluster_size;
+        prealloc_bytes = prealloc_clusters * s->cluster_size;
 
-        /*
-         * We require the expanded size to read back as zero. If the
-         * user permitted truncation, we try that; but if it fails, we
-         * force the safer-but-slower fallocate.
-         */
         if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
-            ret = bdrv_co_truncate(bs->file, host_off + bytes,
-                                   false, PREALLOC_MODE_OFF,
-                                   BDRV_REQ_ZERO_WRITE, NULL);
+            ret = bdrv_truncate(bs->file, host_off + prealloc_bytes, false,
+                                PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL);
             if (ret == -ENOTSUP) {
                 s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
             }
         }
         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
-            ret = bdrv_co_pwrite_zeroes(bs->file, host_off, bytes, 0);
+            ret = bdrv_pwrite_zeroes(bs->file, host_off, prealloc_bytes, 0);
         }
         if (ret < 0) {
             return ret;
@@ -329,15 +302,15 @@  allocate_clusters(BlockDriverState *bs, int64_t sector_num,
         s->used_bmap = bitmap_zero_extend(s->used_bmap, s->used_bmap_size,
                                           new_usedsize);
         s->used_bmap_size = new_usedsize;
+        if (host_off + bytes > s->data_end * BDRV_SECTOR_SIZE) {
+            s->data_end = (host_off + bytes) / BDRV_SECTOR_SIZE;
+        }
     } else {
-        int64_t next_used;
         next_used = find_next_bit(s->used_bmap, s->used_bmap_size, first_free);
 
         /* Not enough continuous clusters in the middle, adjust the size */
-        if (next_used - first_free < to_allocate) {
-            to_allocate = next_used - first_free;
-            *pnum = (idx + to_allocate) * s->tracks - sector_num;
-        }
+        *clusters = MIN(*clusters, next_used - first_free);
+        bytes = *clusters * s->cluster_size;
 
         host_off = s->data_start * BDRV_SECTOR_SIZE;
         host_off += first_free * s->cluster_size;
@@ -349,14 +322,59 @@  allocate_clusters(BlockDriverState *bs, int64_t sector_num,
          */
         if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE &&
                 host_off < s->data_end * BDRV_SECTOR_SIZE) {
-            ret = bdrv_co_pwrite_zeroes(bs->file, host_off,
-                                        s->cluster_size * to_allocate, 0);
+            ret = bdrv_pwrite_zeroes(bs->file, host_off, bytes, 0);
             if (ret < 0) {
                 return ret;
             }
         }
     }
 
+    ret = parallels_mark_used(bs, s->used_bmap, s->used_bmap_size,
+                              host_off, *clusters);
+    if (ret < 0) {
+        /* Image consistency is broken. Alarm! */
+        return ret;
+    }
+
+    return host_off;
+}
+
+static int64_t coroutine_fn GRAPH_RDLOCK
+allocate_clusters(BlockDriverState *bs, int64_t sector_num,
+                  int nb_sectors, int *pnum)
+{
+    int ret = 0;
+    BDRVParallelsState *s = bs->opaque;
+    int64_t i, pos, idx, to_allocate, host_off;
+
+    pos = block_status(s, sector_num, nb_sectors, pnum);
+    if (pos > 0) {
+        return pos;
+    }
+
+    idx = sector_num / s->tracks;
+    to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
+
+    /*
+     * This function is called only by parallels_co_writev(), which will never
+     * pass a sector_num at or beyond the end of the image (because the block
+     * layer never passes such a sector_num to that function). Therefore, idx
+     * is always below s->bat_size.
+     * block_status() will limit *pnum so that sector_num + *pnum will not
+     * exceed the image end. Therefore, idx + to_allocate cannot exceed
+     * s->bat_size.
+     * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
+     * will always fit into a uint32_t.
+     */
+    assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
+
+    host_off = parallels_allocate_host_clusters(bs, &to_allocate);
+    if (host_off < 0) {
+        return host_off;
+    }
+
+    *pnum = MIN(*pnum, (idx + to_allocate) * s->tracks - sector_num);
+
     /*
      * Try to read from backing to fill empty clusters
      * FIXME: 1. previous write_zeroes may be redundant
@@ -373,33 +391,23 @@  allocate_clusters(BlockDriverState *bs, int64_t sector_num,
 
         ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
                             nb_cow_bytes, buf, 0);
-        if (ret < 0) {
-            qemu_vfree(buf);
-            return ret;
+        if (ret == 0) {
+            ret = bdrv_co_pwrite(bs->file, host_off, nb_cow_bytes, buf, 0);
         }
 
-        ret = bdrv_co_pwrite(bs->file, s->data_end * BDRV_SECTOR_SIZE,
-                             nb_cow_bytes, buf, 0);
         qemu_vfree(buf);
         if (ret < 0) {
+            parallels_mark_unused(bs, s->used_bmap, s->used_bmap_size,
+                                  host_off, to_allocate);
             return ret;
         }
     }
 
-    ret = parallels_mark_used(bs, s->used_bmap, s->used_bmap_size,
-                              host_off, to_allocate);
-    if (ret < 0) {
-        /* Image consistency is broken. Alarm! */
-        return ret;
-    }
     for (i = 0; i < to_allocate; i++) {
         parallels_set_bat_entry(s, idx + i,
                 host_off / BDRV_SECTOR_SIZE / s->off_multiplier);
         host_off += s->cluster_size;
     }
-    if (host_off > s->data_end * BDRV_SECTOR_SIZE) {
-        s->data_end = host_off / BDRV_SECTOR_SIZE;
-    }
 
     return bat2sect(s, idx) + sector_num % s->tracks;
 }
diff --git a/block/parallels.h b/block/parallels.h
index 02b857b4a4..493c89e976 100644
--- a/block/parallels.h
+++ b/block/parallels.h
@@ -95,6 +95,9 @@  int parallels_mark_used(BlockDriverState *bs, unsigned long *bitmap,
 int parallels_mark_unused(BlockDriverState *bs, unsigned long *bitmap,
                           uint32_t bitmap_size, int64_t off, uint32_t count);
 
+int64_t GRAPH_RDLOCK parallels_allocate_host_clusters(BlockDriverState *bs,
+                                                      int64_t *clusters);
+
 int GRAPH_RDLOCK
 parallels_read_format_extension(BlockDriverState *bs, int64_t ext_off,
                                 Error **errp);