[Qemu-devel] [PATCH v3 29/39] qcow2: Prepare expand_zero_clusters_in_l1() for adding L2 slice support

Alberto Garcia posted 39 patches 8 years ago
There is a newer version of this series
[Qemu-devel] [PATCH v3 29/39] qcow2: Prepare expand_zero_clusters_in_l1() for adding L2 slice support
Posted by Alberto Garcia 8 years ago
Adding support for L2 slices to expand_zero_clusters_in_l1() needs
(among other things) an extra loop that iterates over all slices of
each L2 table.

Putting all changes in one patch would make it hard to read because
all semantic changes would be mixed with pure indentation changes.

To make things easier this patch simply creates a new block and
changes the indentation of all lines of code inside it. Thus, all
modifications in this patch are cosmetic. There are no semantic
changes and no variables are renamed yet. The next patch will take
care of that.

Signed-off-by: Alberto Garcia <berto@igalia.com>
---
 block/qcow2-cluster.c | 187 ++++++++++++++++++++++++++------------------------
 1 file changed, 96 insertions(+), 91 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 1338485184..6042ec69e3 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1905,118 +1905,123 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
             goto fail;
         }
 
-        if (is_active_l1) {
-            /* get active L2 tables from cache */
-            ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset,
-                    (void **)&l2_table);
-        } else {
-            /* load inactive L2 tables from disk */
-            ret = bdrv_read(bs->file, l2_offset / BDRV_SECTOR_SIZE,
-                            (void *)l2_table, s->cluster_sectors);
-        }
-        if (ret < 0) {
-            goto fail;
-        }
-
-        for (j = 0; j < s->l2_size; j++) {
-            uint64_t l2_entry = be64_to_cpu(l2_table[j]);
-            int64_t offset = l2_entry & L2E_OFFSET_MASK;
-            QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
-
-            if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
-                cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
-                continue;
+        {
+            if (is_active_l1) {
+                /* get active L2 tables from cache */
+                ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset,
+                                      (void **)&l2_table);
+            } else {
+                /* load inactive L2 tables from disk */
+                ret = bdrv_read(bs->file, l2_offset / BDRV_SECTOR_SIZE,
+                                (void *)l2_table, s->cluster_sectors);
             }
+            if (ret < 0) {
+                goto fail;
+            }
+
+            for (j = 0; j < s->l2_size; j++) {
+                uint64_t l2_entry = be64_to_cpu(l2_table[j]);
+                int64_t offset = l2_entry & L2E_OFFSET_MASK;
+                QCow2ClusterType cluster_type =
+                    qcow2_get_cluster_type(l2_entry);
 
-            if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
-                if (!bs->backing) {
-                    /* not backed; therefore we can simply deallocate the
-                     * cluster */
-                    l2_table[j] = 0;
-                    l2_dirty = true;
+                if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
+                    cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
                     continue;
                 }
 
-                offset = qcow2_alloc_clusters(bs, s->cluster_size);
-                if (offset < 0) {
-                    ret = offset;
-                    goto fail;
-                }
+                if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+                    if (!bs->backing) {
+                        /* not backed; therefore we can simply deallocate the
+                         * cluster */
+                        l2_table[j] = 0;
+                        l2_dirty = true;
+                        continue;
+                    }
 
-                if (l2_refcount > 1) {
-                    /* For shared L2 tables, set the refcount accordingly (it is
-                     * already 1 and needs to be l2_refcount) */
-                    ret = qcow2_update_cluster_refcount(bs,
-                            offset >> s->cluster_bits,
+                    offset = qcow2_alloc_clusters(bs, s->cluster_size);
+                    if (offset < 0) {
+                        ret = offset;
+                        goto fail;
+                    }
+
+                    if (l2_refcount > 1) {
+                        /* For shared L2 tables, set the refcount accordingly
+                         * (it is already 1 and needs to be l2_refcount) */
+                        ret = qcow2_update_cluster_refcount(
+                            bs, offset >> s->cluster_bits,
                             refcount_diff(1, l2_refcount), false,
                             QCOW2_DISCARD_OTHER);
-                    if (ret < 0) {
+                        if (ret < 0) {
+                            qcow2_free_clusters(bs, offset, s->cluster_size,
+                                                QCOW2_DISCARD_OTHER);
+                            goto fail;
+                        }
+                    }
+                }
+
+                if (offset_into_cluster(s, offset)) {
+                    qcow2_signal_corruption(
+                        bs, true, -1, -1,
+                        "Cluster allocation offset "
+                        "%#" PRIx64 " unaligned (L2 offset: %#"
+                        PRIx64 ", L2 index: %#x)", offset,
+                        l2_offset, j);
+                    if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
                         qcow2_free_clusters(bs, offset, s->cluster_size,
-                                            QCOW2_DISCARD_OTHER);
-                        goto fail;
+                                            QCOW2_DISCARD_ALWAYS);
                     }
+                    ret = -EIO;
+                    goto fail;
                 }
-            }
 
-            if (offset_into_cluster(s, offset)) {
-                qcow2_signal_corruption(bs, true, -1, -1,
-                                        "Cluster allocation offset "
-                                        "%#" PRIx64 " unaligned (L2 offset: %#"
-                                        PRIx64 ", L2 index: %#x)", offset,
-                                        l2_offset, j);
-                if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
-                    qcow2_free_clusters(bs, offset, s->cluster_size,
-                                        QCOW2_DISCARD_ALWAYS);
+                ret = qcow2_pre_write_overlap_check(bs, 0, offset,
+                                                    s->cluster_size);
+                if (ret < 0) {
+                    if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+                        qcow2_free_clusters(bs, offset, s->cluster_size,
+                                            QCOW2_DISCARD_ALWAYS);
+                    }
+                    goto fail;
                 }
-                ret = -EIO;
-                goto fail;
-            }
 
-            ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size);
-            if (ret < 0) {
-                if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
-                    qcow2_free_clusters(bs, offset, s->cluster_size,
-                                        QCOW2_DISCARD_ALWAYS);
+                ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
+                if (ret < 0) {
+                    if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
+                        qcow2_free_clusters(bs, offset, s->cluster_size,
+                                            QCOW2_DISCARD_ALWAYS);
+                    }
+                    goto fail;
                 }
-                goto fail;
-            }
 
-            ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
-            if (ret < 0) {
-                if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
-                    qcow2_free_clusters(bs, offset, s->cluster_size,
-                                        QCOW2_DISCARD_ALWAYS);
+                if (l2_refcount == 1) {
+                    l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED);
+                } else {
+                    l2_table[j] = cpu_to_be64(offset);
                 }
-                goto fail;
+                l2_dirty = true;
             }
 
-            if (l2_refcount == 1) {
-                l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED);
+            if (is_active_l1) {
+                if (l2_dirty) {
+                    qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table);
+                    qcow2_cache_depends_on_flush(s->l2_table_cache);
+                }
+                qcow2_cache_put(s->l2_table_cache, (void **) &l2_table);
             } else {
-                l2_table[j] = cpu_to_be64(offset);
-            }
-            l2_dirty = true;
-        }
+                if (l2_dirty) {
+                    ret = qcow2_pre_write_overlap_check(
+                        bs, QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2,
+                        l2_offset, s->cluster_size);
+                    if (ret < 0) {
+                        goto fail;
+                    }
 
-        if (is_active_l1) {
-            if (l2_dirty) {
-                qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table);
-                qcow2_cache_depends_on_flush(s->l2_table_cache);
-            }
-            qcow2_cache_put(s->l2_table_cache, (void **) &l2_table);
-        } else {
-            if (l2_dirty) {
-                ret = qcow2_pre_write_overlap_check(bs,
-                        QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2, l2_offset,
-                        s->cluster_size);
-                if (ret < 0) {
-                    goto fail;
-                }
-
-                ret = bdrv_write(bs->file, l2_offset / BDRV_SECTOR_SIZE,
-                                 (void *)l2_table, s->cluster_sectors);
-                if (ret < 0) {
-                    goto fail;
+                    ret = bdrv_write(bs->file, l2_offset / BDRV_SECTOR_SIZE,
+                                     (void *)l2_table, s->cluster_sectors);
+                    if (ret < 0) {
+                        goto fail;
+                    }
                 }
             }
         }
-- 
2.11.0


Re: [Qemu-devel] [PATCH v3 29/39] qcow2: Prepare expand_zero_clusters_in_l1() for adding L2 slice support
Posted by Eric Blake 8 years ago
On 01/26/2018 08:59 AM, Alberto Garcia wrote:
> Adding support for L2 slices to expand_zero_clusters_in_l1() needs
> (among other things) an extra loop that iterates over all slices of
> each L2 table.
> 
> Putting all changes in one patch would make it hard to read because
> all semantic changes would be mixed with pure indentation changes.
> 
> To make things easier this patch simply creates a new block and
> changes the indentation of all lines of code inside it. Thus, all
> modifications in this patch are cosmetic. There are no semantic
> changes and no variables are renamed yet. The next patch will take
> care of that.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
>  block/qcow2-cluster.c | 187 ++++++++++++++++++++++++++------------------------
>  1 file changed, 96 insertions(+), 91 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v3 29/39] qcow2: Prepare expand_zero_clusters_in_l1() for adding L2 slice support
Posted by Max Reitz 8 years ago
On 2018-01-26 15:59, Alberto Garcia wrote:
> Adding support for L2 slices to expand_zero_clusters_in_l1() needs
> (among other things) an extra loop that iterates over all slices of
> each L2 table.
> 
> Putting all changes in one patch would make it hard to read because
> all semantic changes would be mixed with pure indentation changes.
> 
> To make things easier this patch simply creates a new block and
> changes the indentation of all lines of code inside it. Thus, all
> modifications in this patch are cosmetic. There are no semantic
> changes and no variables are renamed yet. The next patch will take
> care of that.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
>  block/qcow2-cluster.c | 187 ++++++++++++++++++++++++++------------------------
>  1 file changed, 96 insertions(+), 91 deletions(-)

Reviewed-by: Max Reitz <mreitz@redhat.com>