[Qemu-devel] [PATCH v5 0/6] block/qcow2: Image file option amendment

[Qemu-devel] [PATCH v5 0/6] block/qcow2: Image file option amendment

[Max Reitz]

This series adds support to qemu-img, block and qcow2 for amending image
options on existing image files.

Depends on:
 - option: Add assigned flag to QEMUOptionParameter
 - qcow2-refcount: Snapshot update for zero clusters (series, v3)
 - Add metadata overlap checks (series, v5)

v5:
 - added a new function for emptying a cache (patch 2)
 - fixed rounding for the bitmap size in qcow2_expand_zero_clusters
 - now empties the cache in qcow2_expand_zero_clusters instead of simply
   flushing it
 - factored out assignment check in qcow2_amend_options
 - fixed resizing by moving it to the end of qcow2_amend_options
 - fixed expected test result for resizing in addition to a version
   upgrade

v4:
 - rebased on the metadata overlap check series (and fit to it)
 - split patch 2 into three distinct patches (2, 3 and 4)
 - extended test for zero expansion on backed and inactive backed clusters
   (and fixed according to the metadata overlap check series (i.e.,
   adjusted header length))
 - fixed zero expansion with shared L2 tables

v3:
 - deallocate non-preallocated zero clusters on non-backed images instead
   of zero expanding them
 - qcow2 version downgrade: error out on refcount_order != 4
 - implemented Eric's comments regarding the qemu-img amend and img_amend
   itself

v2:
 - Generally implemented Kevin's comments, especially:
   - Zero cluster expansion for inactive L2 tables
   - Correct handling of preallocated zero clusters
   - More test cases

Max Reitz (6):
  block: Image file option amendment
  qcow2-cache: Empty cache
  qcow2-cluster: Expand zero clusters
  qcow2: Save refcount order in BDRVQcowState
  qcow2: Implement bdrv_amend_options
  qemu-iotest: qcow2 image option amendment

 block.c                    |   8 ++
 block/qcow2-cache.c        |  18 +++
 block/qcow2-cluster.c      | 233 ++++++++++++++++++++++++++++++
 block/qcow2-refcount.c     |  29 ++--
 block/qcow2.c              | 197 ++++++++++++++++++++++++-
 block/qcow2.h              |   8 ++
 include/block/block.h      |   2 +
 include/block/block_int.h  |   3 +
 qemu-img-cmds.hx           |   6 +
 qemu-img.c                 |  84 +++++++++++
 qemu-img.texi              |   5 +
 tests/qemu-iotests/061     | 178 +++++++++++++++++++++++
 tests/qemu-iotests/061.out | 349 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 14 files changed, 1106 insertions(+), 15 deletions(-)
 create mode 100755 tests/qemu-iotests/061
 create mode 100644 tests/qemu-iotests/061.out

-- 
1.8.3.1

[Qemu-devel] [PATCH v5 1/6] block: Image file option amendment

[Max Reitz]

This patch adds the "amend" option to qemu-img which allows changing
image options on existing image files. It also adds the generic bdrv
implementation which is basically just a wrapper for the image format
specific function.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c                   |  8 +++++
 include/block/block.h     |  2 ++
 include/block/block_int.h |  3 ++
 qemu-img-cmds.hx          |  6 ++++
 qemu-img.c                | 84 +++++++++++++++++++++++++++++++++++++++++++++++
 qemu-img.texi             |  5 +++
 6 files changed, 108 insertions(+)

diff --git a/block.c b/block.c
index a387c1a..9c40a15 100644
--- a/block.c
+++ b/block.c
@@ -4674,3 +4674,11 @@ void bdrv_add_before_write_notifier(BlockDriverState *bs,
 {
     notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
 }
+
+int bdrv_amend_options(BlockDriverState *bs, QEMUOptionParameter *options)
+{
+    if (bs->drv->bdrv_amend_options == NULL) {
+        return -ENOTSUP;
+    }
+    return bs->drv->bdrv_amend_options(bs, options);
+}
diff --git a/include/block/block.h b/include/block/block.h
index e6b391c..c284b4a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -223,6 +223,8 @@ typedef enum {
 
 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 
+int bdrv_amend_options(BlockDriverState *bs_new, QEMUOptionParameter *options);
+
 /* async block I/O */
 typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,
                                      int sector_num);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 8012e25..3c93766 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -205,6 +205,9 @@ struct BlockDriver {
     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
         BdrvCheckMode fix);
 
+    int (*bdrv_amend_options)(BlockDriverState *bs,
+        QEMUOptionParameter *options);
+
     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 
     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 4ca7e95..5a066b5 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -61,5 +61,11 @@ DEF("resize", img_resize,
     "resize [-q] filename [+ | -]size")
 STEXI
 @item resize [-q] @var{filename} [+ | -]@var{size}
+ETEXI
+
+DEF("amend", img_amend,
+    "amend [-q] [-f fmt] -o options filename")
+STEXI
+@item amend [-q] [-f @var{fmt}] -o @var{options} @var{filename}
 @end table
 ETEXI
diff --git a/qemu-img.c b/qemu-img.c
index b9a848d..7a8f064 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2308,6 +2308,90 @@ out:
     return 0;
 }
 
+static int img_amend(int argc, char **argv)
+{
+    int c, ret = 0;
+    char *options = NULL;
+    QEMUOptionParameter *create_options = NULL, *options_param = NULL;
+    const char *fmt = NULL, *filename;
+    bool quiet = false;
+    BlockDriverState *bs = NULL;
+
+    for (;;) {
+        c = getopt(argc, argv, "hqf:o:");
+        if (c == -1) {
+            break;
+        }
+
+        switch (c) {
+            case 'h':
+            case '?':
+                help();
+                break;
+            case 'o':
+                options = optarg;
+                break;
+            case 'f':
+                fmt = optarg;
+                break;
+            case 'q':
+                quiet = true;
+                break;
+        }
+    }
+
+    if (optind != argc - 1) {
+        help();
+    }
+
+    if (!options) {
+        help();
+    }
+
+    filename = argv[argc - 1];
+
+    bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
+    if (!bs) {
+        error_report("Could not open image '%s'", filename);
+        ret = -1;
+        goto out;
+    }
+
+    fmt = bs->drv->format_name;
+
+    if (is_help_option(options)) {
+        ret = print_block_option_help(filename, fmt);
+        goto out;
+    }
+
+    create_options = append_option_parameters(create_options,
+            bs->drv->create_options);
+    options_param = parse_option_parameters(options, create_options,
+            options_param);
+    if (options_param == NULL) {
+        error_report("Invalid options for file format '%s'", fmt);
+        ret = -1;
+        goto out;
+    }
+
+    ret = bdrv_amend_options(bs, options_param);
+    if (ret < 0) {
+        error_report("Error while amending options: %s", strerror(-ret));
+        goto out;
+    }
+
+out:
+    if (bs) {
+        bdrv_delete(bs);
+    }
+    free_option_parameters(create_options);
+    free_option_parameters(options_param);
+    if (ret) {
+        return 1;
+    }
+    return 0;
+}
+
 static const img_cmd_t img_cmds[] = {
 #define DEF(option, callback, arg_string)        \
     { option, callback },
diff --git a/qemu-img.texi b/qemu-img.texi
index 69f1bda..8697f23 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -282,6 +282,11 @@ sizes accordingly.  Failure to do so will result in data loss!
 After using this command to grow a disk image, you must use file system and
 partitioning tools inside the VM to actually begin using the new space on the
 device.
+
+@item amend [-f @var{fmt}] -o @var{options} @var{filename}
+
+Amends the image format specific @var{options} for the image file
+@var{filename}. Not all file formats support this operation.
 @end table
 @c man end
 
-- 
1.8.3.1

[Qemu-devel] [PATCH v5 2/6] qcow2-cache: Empty cache

[Max Reitz]

Add a function for emptying a cache, i.e., flushing it and marking all
elements invalid.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2-cache.c | 18 ++++++++++++++++++
 block/qcow2.h       |  2 ++
 2 files changed, 20 insertions(+)

diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c
index 7bcae09..40a5a3f 100644
--- a/block/qcow2-cache.c
+++ b/block/qcow2-cache.c
@@ -202,6 +202,24 @@ void qcow2_cache_depends_on_flush(Qcow2Cache *c)
     c->depends_on_flush = true;
 }
 
+int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c)
+{
+    int ret, i;
+
+    ret = qcow2_cache_flush(bs, c);
+    if (ret < 0) {
+        return ret;
+    }
+
+    for (i = 0; i < c->size; i++) {
+        assert(c->entries[i].ref == 0);
+        c->entries[i].offset = 0;
+        c->entries[i].cache_hits = 0;
+    }
+
+    return 0;
+}
+
 static int qcow2_cache_find_entry_to_replace(Qcow2Cache *c)
 {
     int i;
diff --git a/block/qcow2.h b/block/qcow2.h
index 10b7bf4..3db0877 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -473,6 +473,8 @@ int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
     Qcow2Cache *dependency);
 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 
+int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
+
 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
     void **table);
 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
-- 
1.8.3.1

[Qemu-devel] [PATCH v5 3/6] qcow2-cluster: Expand zero clusters

[Max Reitz]

Add functionality for expanding zero clusters. This is necessary for
downgrading the image version to one without zero cluster support.

For non-backed images, this function may also just discard zero clusters
instead of truly expanding them.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2-cluster.c  | 233 +++++++++++++++++++++++++++++++++++++++++++++++++
 block/qcow2-refcount.c |  29 +++---
 block/qcow2.h          |   5 ++
 3 files changed, 253 insertions(+), 14 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 2d5aa92..cc16312 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1497,3 +1497,236 @@ fail:
 
     return ret;
 }
+
+/*
+ * Expands all zero clusters in a specific L1 table (or deallocates them, for
+ * non-backed non-pre-allocated zero clusters).
+ *
+ * expanded_clusters is a bitmap where every bit corresponds to one cluster in
+ * the image file; a bit gets set if the corresponding cluster has been used for
+ * zero expansion (i.e., has been filled with zeroes and is referenced from an
+ * L2 table). nb_clusters contains the total cluster count of the image file,
+ * i.e., the number of bits in expanded_clusters.
+ */
+static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
+                                      int l1_size, uint8_t *expanded_clusters,
+                                      uint64_t nb_clusters)
+{
+    BDRVQcowState *s = bs->opaque;
+    bool is_active_l1 = (l1_table == s->l1_table);
+    uint64_t *l2_table = NULL;
+    int ret;
+    int i, j;
+
+    if (!is_active_l1) {
+        /* inactive L2 tables require a buffer to be stored in when loading
+         * them from disk */
+        l2_table = qemu_blockalign(bs, s->cluster_size);
+    }
+
+    for (i = 0; i < l1_size; i++) {
+        uint64_t l2_offset = l1_table[i] & L1E_OFFSET_MASK;
+        bool l2_dirty = false;
+
+        if (!l2_offset) {
+            /* unallocated */
+            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, cluster_index;
+            int cluster_type = qcow2_get_cluster_type(l2_entry);
+
+            if (cluster_type == QCOW2_CLUSTER_NORMAL) {
+                cluster_index = offset >> s->cluster_bits;
+                assert((cluster_index >= 0) && (cluster_index < nb_clusters));
+                if (expanded_clusters[cluster_index / 8] &
+                    (1 << (cluster_index % 8))) {
+                    /* Probably a shared L2 table; this cluster was a zero
+                     * cluster which has been expanded, its refcount
+                     * therefore most likely requires an update. */
+                    ret = qcow2_update_cluster_refcount(bs, cluster_index, 1,
+                                                        QCOW2_DISCARD_NEVER);
+                    if (ret < 0) {
+                        goto fail;
+                    }
+                    /* Since we just increased the refcount, the COPIED flag may
+                     * no longer be set. */
+                    l2_table[j] = cpu_to_be64(l2_entry & ~QCOW_OFLAG_COPIED);
+                    l2_dirty = true;
+                }
+                continue;
+            }
+            else if (qcow2_get_cluster_type(l2_entry) != QCOW2_CLUSTER_ZERO) {
+                continue;
+            }
+
+            if (!offset) {
+                /* not preallocated */
+                if (!bs->backing_hd) {
+                    /* not backed; therefore we can simply deallocate the
+                     * cluster */
+                    l2_table[j] = 0;
+                    l2_dirty = true;
+                    continue;
+                }
+
+                offset = qcow2_alloc_clusters(bs, s->cluster_size);
+                if (offset < 0) {
+                    ret = offset;
+                    goto fail;
+                }
+            }
+
+            ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,
+                                                offset, s->cluster_size);
+            if (ret < 0) {
+                qcow2_free_clusters(bs, offset, s->cluster_size,
+                        QCOW2_DISCARD_ALWAYS);
+                goto fail;
+            }
+
+            ret = bdrv_write_zeroes(bs->file, offset / BDRV_SECTOR_SIZE,
+                                    s->cluster_sectors);
+            if (ret < 0) {
+                qcow2_free_clusters(bs, offset, s->cluster_size,
+                        QCOW2_DISCARD_ALWAYS);
+                goto fail;
+            }
+
+            l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED);
+            l2_dirty = true;
+
+            cluster_index = offset >> s->cluster_bits;
+            assert((cluster_index >= 0) && (cluster_index < nb_clusters));
+            expanded_clusters[cluster_index / 8] |= 1 << (cluster_index % 8);
+        }
+
+        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);
+            }
+            ret = qcow2_cache_put(bs, s->l2_table_cache, (void **)&l2_table);
+            if (ret < 0) {
+                l2_table = NULL;
+                goto fail;
+            }
+        } else {
+            if (l2_dirty) {
+                ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT &
+                        ~(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 = 0;
+
+fail:
+    if (l2_table) {
+        if (!is_active_l1) {
+            qemu_vfree(l2_table);
+        } else {
+            if (ret < 0) {
+                qcow2_cache_put(bs, s->l2_table_cache, (void **)&l2_table);
+            } else {
+                ret = qcow2_cache_put(bs, s->l2_table_cache,
+                        (void **)&l2_table);
+            }
+        }
+    }
+    return ret;
+}
+
+/*
+ * For backed images, expands all zero clusters on the image. For non-backed
+ * images, deallocates all non-pre-allocated zero clusters (and claims the
+ * allocation for pre-allocated ones). This is important for downgrading to a
+ * qcow2 version which doesn't yet support metadata zero clusters.
+ */
+int qcow2_expand_zero_clusters(BlockDriverState *bs)
+{
+    BDRVQcowState *s = bs->opaque;
+    uint64_t *l1_table = NULL;
+    int cluster_to_sector_bits = s->cluster_bits - BDRV_SECTOR_BITS;
+    uint64_t nb_clusters;
+    uint8_t *expanded_clusters;
+    int ret;
+    int i, j;
+
+    nb_clusters = (bs->total_sectors + (1 << cluster_to_sector_bits) - 1)
+            >> cluster_to_sector_bits;
+    expanded_clusters = g_malloc0((nb_clusters + 7) / 8);
+
+    ret = expand_zero_clusters_in_l1(bs, s->l1_table, s->l1_size,
+                                     expanded_clusters, nb_clusters);
+    if (ret < 0) {
+        goto fail;
+    }
+
+    /* Inactive L1 tables may point to active L2 tables - therefore it is
+     * necessary to flush the L2 table cache before trying to access the L2
+     * tables pointed to by inactive L1 entries (else we might try to expand
+     * zero clusters that have already been expanded); furthermore, it is also
+     * necessary to empty the L2 table cache, since it may contain tables which
+     * are now going to be modified directly on disk, bypassing the cache.
+     * qcow2_cache_empty() does both for us. */
+    ret = qcow2_cache_empty(bs, s->l2_table_cache);
+    if (ret < 0) {
+        goto fail;
+    }
+
+    for (i = 0; i < s->nb_snapshots; i++) {
+        int l1_sectors = (s->snapshots[i].l1_size * sizeof(uint64_t) +
+                BDRV_SECTOR_SIZE - 1) / BDRV_SECTOR_SIZE;
+
+        l1_table = g_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE);
+
+        ret = bdrv_read(bs->file, s->snapshots[i].l1_table_offset /
+                BDRV_SECTOR_SIZE, (void *)l1_table, l1_sectors);
+        if (ret < 0) {
+            goto fail;
+        }
+
+        for (j = 0; j < s->snapshots[i].l1_size; j++) {
+            be64_to_cpus(&l1_table[j]);
+        }
+
+        ret = expand_zero_clusters_in_l1(bs, l1_table, s->snapshots[i].l1_size,
+                                         expanded_clusters, nb_clusters);
+        if (ret < 0) {
+            goto fail;
+        }
+    }
+
+    ret = 0;
+
+fail:
+    g_free(expanded_clusters);
+    g_free(l1_table);
+    return ret;
+}
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index ba129de..4264148 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -601,10 +601,10 @@ fail:
  * If the return value is non-negative, it is the new refcount of the cluster.
  * If it is negative, it is -errno and indicates an error.
  */
-static int update_cluster_refcount(BlockDriverState *bs,
-                                   int64_t cluster_index,
-                                   int addend,
-                                   enum qcow2_discard_type type)
+int qcow2_update_cluster_refcount(BlockDriverState *bs,
+                                  int64_t cluster_index,
+                                  int addend,
+                                  enum qcow2_discard_type type)
 {
     BDRVQcowState *s = bs->opaque;
     int ret;
@@ -733,8 +733,8 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
         if (free_in_cluster == 0)
             s->free_byte_offset = 0;
         if ((offset & (s->cluster_size - 1)) != 0)
-            update_cluster_refcount(bs, offset >> s->cluster_bits, 1,
-                                    QCOW2_DISCARD_NEVER);
+            qcow2_update_cluster_refcount(bs, offset >> s->cluster_bits, 1,
+                                          QCOW2_DISCARD_NEVER);
     } else {
         offset = qcow2_alloc_clusters(bs, s->cluster_size);
         if (offset < 0) {
@@ -744,8 +744,8 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
         if ((cluster_offset + s->cluster_size) == offset) {
             /* we are lucky: contiguous data */
             offset = s->free_byte_offset;
-            update_cluster_refcount(bs, offset >> s->cluster_bits, 1,
-                                    QCOW2_DISCARD_NEVER);
+            qcow2_update_cluster_refcount(bs, offset >> s->cluster_bits, 1,
+                                          QCOW2_DISCARD_NEVER);
             s->free_byte_offset += size;
         } else {
             s->free_byte_offset = offset;
@@ -754,8 +754,8 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
     }
 
     /* The cluster refcount was incremented, either by qcow2_alloc_clusters()
-     * or explicitly by update_cluster_refcount().  Refcount blocks must be
-     * flushed before the caller's L2 table updates.
+     * or explicitly by qcow2_update_cluster_refcount().  Refcount blocks must
+     * be flushed before the caller's L2 table updates.
      */
     qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache);
     return offset;
@@ -896,8 +896,9 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
                             break;
                         }
                         if (addend != 0) {
-                            refcount = update_cluster_refcount(bs, cluster_index, addend,
-                                                               QCOW2_DISCARD_SNAPSHOT);
+                            refcount = qcow2_update_cluster_refcount(bs,
+                                    cluster_index, addend,
+                                    QCOW2_DISCARD_SNAPSHOT);
                         } else {
                             refcount = get_refcount(bs, cluster_index);
                         }
@@ -936,8 +937,8 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 
 
             if (addend != 0) {
-                refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend,
-                                                   QCOW2_DISCARD_SNAPSHOT);
+                refcount = qcow2_update_cluster_refcount(bs, l2_offset >>
+                        s->cluster_bits, addend, QCOW2_DISCARD_SNAPSHOT);
             } else {
                 refcount = get_refcount(bs, l2_offset >> s->cluster_bits);
             }
diff --git a/block/qcow2.h b/block/qcow2.h
index 3db0877..bb25213 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -406,6 +406,9 @@ int qcow2_update_header(BlockDriverState *bs);
 int qcow2_refcount_init(BlockDriverState *bs);
 void qcow2_refcount_close(BlockDriverState *bs);
 
+int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
+                                  int addend, enum qcow2_discard_type type);
+
 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
 int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
     int nb_clusters);
@@ -453,6 +456,8 @@ int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
     int nb_sectors);
 int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
 
+int qcow2_expand_zero_clusters(BlockDriverState *bs);
+
 /* qcow2-snapshot.c functions */
 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
-- 
1.8.3.1

[Qemu-devel] [PATCH v5 4/6] qcow2: Save refcount order in BDRVQcowState

[Max Reitz]

Save the image refcount order in BDRVQcowState. This will be relevant
for future code supporting different refcount orders than four and also
for code that needs to verify a certain refcount order for an opened
image.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.c | 3 ++-
 block/qcow2.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index aeb2ebb..28b104e 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -455,6 +455,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
         ret = -ENOTSUP;
         goto fail;
     }
+    s->refcount_order = header.refcount_order;
 
     if (header.cluster_bits < MIN_CLUSTER_BITS ||
         header.cluster_bits > MAX_CLUSTER_BITS) {
@@ -1133,7 +1134,7 @@ int qcow2_update_header(BlockDriverState *bs)
         .incompatible_features  = cpu_to_be64(s->incompatible_features),
         .compatible_features    = cpu_to_be64(s->compatible_features),
         .autoclear_features     = cpu_to_be64(s->autoclear_features),
-        .refcount_order         = cpu_to_be32(3 + REFCOUNT_SHIFT),
+        .refcount_order         = cpu_to_be32(s->refcount_order),
         .header_length          = cpu_to_be32(header_length),
     };
 
diff --git a/block/qcow2.h b/block/qcow2.h
index bb25213..1e28fc1 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -199,6 +199,7 @@ typedef struct BDRVQcowState {
     int flags;
     int qcow_version;
     bool use_lazy_refcounts;
+    int refcount_order;
 
     bool discard_passthrough[QCOW2_DISCARD_MAX];
 
-- 
1.8.3.1

[Qemu-devel] [PATCH v5 5/6] qcow2: Implement bdrv_amend_options

[Max Reitz]

Implement bdrv_amend_options for compat, size, backing_file, backing_fmt
and lazy_refcounts.

Downgrading images from compat=1.1 to compat=0.10 is achieved through
handling all incompatible flags accordingly, clearing all compatible and
autoclear flags and expanding all zero clusters.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.c | 194 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 194 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 28b104e..d29547b 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1813,6 +1813,199 @@ static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
     return ret;
 }
 
+/*
+ * Downgrades an image's version. To achieve this, any incompatible features
+ * have to be removed.
+ */
+static int qcow2_downgrade(BlockDriverState *bs, int target_version)
+{
+    BDRVQcowState *s = bs->opaque;
+    int current_version = s->qcow_version;
+    int ret;
+
+    if (target_version == current_version) {
+        return 0;
+    } else if (target_version > current_version) {
+        return -EINVAL;
+    } else if (target_version != 2) {
+        return -EINVAL;
+    }
+
+    if (s->refcount_order != 4) {
+        /* we would have to convert the image to a refcount_order == 4 image
+         * here; however, since qemu (at the time of writing this) does not
+         * support anything different than 4 anyway, there is no point in doing
+         * so right now; however, we should error out (if qemu supports this in
+         * the future and this code has not been adapted) */
+        error_report("qcow2_downgrade: Image refcount orders other than 4 are"
+                     "currently not supported.");
+        return -ENOTSUP;
+    }
+
+    /* clear incompatible features */
+    if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
+        ret = qcow2_mark_clean(bs);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
+     * the first place; if that happens nonetheless, returning -ENOTSUP is the
+     * best thing to do anyway */
+
+    if (s->incompatible_features) {
+        return -ENOTSUP;
+    }
+
+    /* since we can ignore compatible features, we can set them to 0 as well */
+    s->compatible_features = 0;
+    /* if lazy refcounts have been used, they have already been fixed through
+     * clearing the dirty flag */
+
+    /* clearing autoclear features is trivial */
+    s->autoclear_features = 0;
+
+    ret = qcow2_expand_zero_clusters(bs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    s->qcow_version = target_version;
+    ret = qcow2_update_header(bs);
+    if (ret < 0) {
+        s->qcow_version = current_version;
+        return ret;
+    }
+    return 0;
+}
+
+static int qcow2_amend_options(BlockDriverState *bs,
+                               QEMUOptionParameter *options)
+{
+    BDRVQcowState *s = bs->opaque;
+    int old_version = s->qcow_version, new_version = old_version;
+    uint64_t new_size = 0;
+    const char *backing_file = NULL, *backing_format = NULL;
+    bool lazy_refcounts = s->use_lazy_refcounts;
+    int ret;
+    int i;
+
+    for (i = 0; options[i].name; i++)
+    {
+        if (!options[i].assigned) {
+            /* only change explicitly defined options */
+            continue;
+        }
+
+        if (!strcmp(options[i].name, "compat")) {
+            if (!options[i].value.s) {
+                /* preserve default */
+            } else if (!strcmp(options[i].value.s, "0.10")) {
+                new_version = 2;
+            } else if (!strcmp(options[i].value.s, "1.1")) {
+                new_version = 3;
+            } else {
+                fprintf(stderr, "Unknown compatibility level %s.\n",
+                        options[i].value.s);
+                return -EINVAL;
+            }
+        } else if (!strcmp(options[i].name, "preallocation")) {
+            fprintf(stderr, "Cannot change preallocation mode.\n");
+            return -ENOTSUP;
+        } else if (!strcmp(options[i].name, "size")) {
+            new_size = options[i].value.n;
+        } else if (!strcmp(options[i].name, "backing_file")) {
+            backing_file = options[i].value.s;
+        } else if (!strcmp(options[i].name, "backing_fmt")) {
+            backing_format = options[i].value.s;
+        } else if (!strcmp(options[i].name, "encryption")) {
+            if ((options[i].value.n != !!s->crypt_method)) {
+                fprintf(stderr, "Changing the encryption flag is not "
+                        "supported.\n");
+                return -ENOTSUP;
+            }
+        } else if (!strcmp(options[i].name, "cluster_size")) {
+            if (options[i].value.n != s->cluster_size) {
+                fprintf(stderr, "Changing the cluster size is not "
+                        "supported.\n");
+                return -ENOTSUP;
+            }
+        } else if (!strcmp(options[i].name, "lazy_refcounts")) {
+            lazy_refcounts = options[i].value.n;
+        } else {
+            /* if this assertion fails, this probably means a new option was
+             * added without having it covered here */
+            assert(false);
+        }
+    }
+
+    if (new_version != old_version) {
+        if (new_version > old_version) {
+            /* Upgrade */
+            s->qcow_version = new_version;
+            ret = qcow2_update_header(bs);
+            if (ret < 0) {
+                s->qcow_version = old_version;
+                return ret;
+            }
+        } else {
+            ret = qcow2_downgrade(bs, new_version);
+            if (ret < 0) {
+                return ret;
+            }
+        }
+    }
+
+    if (backing_file || backing_format) {
+        ret = qcow2_change_backing_file(bs, backing_file ?: bs->backing_file,
+                                        backing_format ?: bs->backing_format);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    if (s->use_lazy_refcounts != lazy_refcounts) {
+        if (lazy_refcounts) {
+            if (s->qcow_version < 3) {
+                fprintf(stderr, "Lazy refcounts only supported with compatibility "
+                        "level 1.1 and above (use compat=1.1 or greater)\n");
+                return -EINVAL;
+            }
+            s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
+            ret = qcow2_update_header(bs);
+            if (ret < 0) {
+                s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
+                return ret;
+            }
+            s->use_lazy_refcounts = true;
+        } else {
+            /* make image clean first */
+            ret = qcow2_mark_clean(bs);
+            if (ret < 0) {
+                return ret;
+            }
+            /* now disallow lazy refcounts */
+            s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
+            ret = qcow2_update_header(bs);
+            if (ret < 0) {
+                s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
+                return ret;
+            }
+            s->use_lazy_refcounts = false;
+        }
+    }
+
+    if (new_size) {
+        ret = qcow2_truncate(bs, new_size);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
 static QEMUOptionParameter qcow2_create_options[] = {
     {
         .name = BLOCK_OPT_SIZE,
@@ -1896,6 +2089,7 @@ static BlockDriver bdrv_qcow2 = {
 
     .create_options = qcow2_create_options,
     .bdrv_check = qcow2_check,
+    .bdrv_amend_options = qcow2_amend_options,
 };
 
 static void bdrv_qcow2_init(void)
-- 
1.8.3.1

[Qemu-devel] [PATCH v5 6/6] qemu-iotest: qcow2 image option amendment

[Max Reitz]

Add tests for qemu-img amend on qcow2 image files.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/061     | 178 +++++++++++++++++++++++
 tests/qemu-iotests/061.out | 349 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 528 insertions(+)
 create mode 100755 tests/qemu-iotests/061
 create mode 100644 tests/qemu-iotests/061.out

diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061
new file mode 100755
index 0000000..86404e6
--- /dev/null
+++ b/tests/qemu-iotests/061
@@ -0,0 +1,178 @@
+#!/bin/bash
+#
+# Test case for image option amendment in qcow2.
+#
+# Copyright (C) 2013 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=mreitz@redhat.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# This tests qocw2-specific low-level functionality
+_supported_fmt qcow2
+_supported_proto generic
+_supported_os Linux
+
+echo
+echo "=== Testing version downgrade with zero expansion ==="
+echo
+IMGOPTS="compat=1.1,lazy_refcounts=on" _make_test_img 64M
+$QEMU_IO -c "write -z 0 128k" "$TEST_IMG" | _filter_qemu_io
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IO -c "read -P 0 0 128k" "$TEST_IMG" | _filter_qemu_io
+_check_test_img
+
+echo
+echo "=== Testing dirty version downgrade ==="
+echo
+IMGOPTS="compat=1.1,lazy_refcounts=on" _make_test_img 64M
+$QEMU_IO -c "write -P 0x2a 0 128k" -c flush -c abort "$TEST_IMG" | _filter_qemu_io
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IO -c "read -P 0x2a 0 128k" "$TEST_IMG" | _filter_qemu_io
+_check_test_img
+
+echo
+echo "=== Testing version downgrade with unknown compat/autoclear flags ==="
+echo
+IMGOPTS="compat=1.1" _make_test_img 64M
+./qcow2.py "$TEST_IMG" set-feature-bit compatible 42
+./qcow2.py "$TEST_IMG" set-feature-bit autoclear 42
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+./qcow2.py "$TEST_IMG" dump-header
+_check_test_img
+
+echo
+echo "=== Testing version upgrade and resize ==="
+echo
+IMGOPTS="compat=0.10" _make_test_img 64M
+$QEMU_IO -c "write -P 0x2a 42M 64k" "$TEST_IMG" | _filter_qemu_io
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IMG amend -o "compat=1.1,lazy_refcounts=on,size=128M" "$TEST_IMG"
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IO -c "read -P 0x2a 42M 64k" "$TEST_IMG" | _filter_qemu_io
+_check_test_img
+
+echo
+echo "=== Testing dirty lazy_refcounts=off ==="
+echo
+IMGOPTS="compat=1.1,lazy_refcounts=on" _make_test_img 64M
+$QEMU_IO -c "write -P 0x2a 0 128k" -c flush -c abort "$TEST_IMG" | _filter_qemu_io
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IMG amend -o "lazy_refcounts=off" "$TEST_IMG"
+./qcow2.py "$TEST_IMG" dump-header
+$QEMU_IO -c "read -P 0x2a 0 128k" "$TEST_IMG" | _filter_qemu_io
+_check_test_img
+
+echo
+echo "=== Testing backing file ==="
+echo
+IMGOPTS="compat=1.1" _make_test_img 64M
+IMGOPTS="compat=1.1" TEST_IMG="$TEST_IMG.base" _make_test_img 64M
+$QEMU_IO -c "write -P 0x2a 0 128k" "$TEST_IMG.base" | _filter_qemu_io
+$QEMU_IO -c "read -P 0 0 128k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG amend -o "backing_file=$TEST_IMG.base,backing_fmt=qcow2" "$TEST_IMG"
+$QEMU_IO -c "read -P 0x2a 0 128k" "$TEST_IMG" | _filter_qemu_io
+_check_test_img
+
+echo
+echo "=== Testing invalid configurations ==="
+echo
+IMGOPTS="compat=0.10" _make_test_img 64M
+$QEMU_IMG amend -o "lazy_refcounts=on" "$TEST_IMG"
+$QEMU_IMG amend -o "compat=1.1" "$TEST_IMG" # actually valid
+$QEMU_IMG amend -o "compat=0.10,lazy_refcounts=on" "$TEST_IMG"
+$QEMU_IMG amend -o "compat=0.42" "$TEST_IMG"
+$QEMU_IMG amend -o "foo=bar" "$TEST_IMG"
+$QEMU_IMG amend -o "cluster_size=1k" "$TEST_IMG"
+$QEMU_IMG amend -o "encryption=on" "$TEST_IMG"
+$QEMU_IMG amend -o "preallocation=on" "$TEST_IMG"
+
+echo
+echo "=== Testing correct handling of unset value ==="
+echo
+IMGOPTS="compat=1.1,cluster_size=1k" _make_test_img 64M
+echo "Should work:"
+$QEMU_IMG amend -o "lazy_refcounts=on" "$TEST_IMG"
+echo "Should not work:" # Just to know which of these tests actually fails
+$QEMU_IMG amend -o "cluster_size=64k" "$TEST_IMG"
+
+echo
+echo "=== Testing zero expansion on inactive clusters ==="
+echo
+IMGOPTS="compat=1.1" _make_test_img 64M
+$QEMU_IO -c "write -z 0 128k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+$QEMU_IO -c "write -P 0x2a 0 128k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+_check_test_img
+$QEMU_IO -c "read -P 0x2a 0 128k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG snapshot -a foo "$TEST_IMG"
+_check_test_img
+$QEMU_IO -c "read -P 0 0 128k" "$TEST_IMG" | _filter_qemu_io
+
+echo
+echo "=== Testing zero expansion on backed image ==="
+echo
+IMGOPTS="compat=1.1" TEST_IMG="$TEST_IMG.base" _make_test_img 64M
+$QEMU_IO -c "write -P 0x2a 0 128k" "$TEST_IMG.base" | _filter_qemu_io
+IMGOPTS="compat=1.1,backing_file=$TEST_IMG.base" _make_test_img 64M
+$QEMU_IO -c "read -P 0x2a 0 128k" -c "write -z 0 64k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+_check_test_img
+$QEMU_IO -c "read -P 0 0 64k" -c "read -P 0x2a 64k 64k" "$TEST_IMG" | _filter_qemu_io
+
+echo
+echo "=== Testing zero expansion on backed inactive clusters ==="
+echo
+IMGOPTS="compat=1.1" TEST_IMG="$TEST_IMG.base" _make_test_img 64M
+$QEMU_IO -c "write -P 0x2a 0 128k" "$TEST_IMG.base" | _filter_qemu_io
+IMGOPTS="compat=1.1,backing_file=$TEST_IMG.base" _make_test_img 64M
+$QEMU_IO -c "write -z 0 64k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+$QEMU_IO -c "write -P 0x42 0 128k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG amend -o "compat=0.10" "$TEST_IMG"
+_check_test_img
+$QEMU_IO -c "read -P 0x42 0 128k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG snapshot -a foo "$TEST_IMG"
+_check_test_img
+$QEMU_IO -c "read -P 0 0 64k" -c "read -P 0x2a 64k 64k" "$TEST_IMG" | _filter_qemu_io
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out
new file mode 100644
index 0000000..05bd1d5
--- /dev/null
+++ b/tests/qemu-iotests/061.out
@@ -0,0 +1,349 @@
+QA output created by 061
+
+=== Testing version downgrade with zero expansion ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x1
+autoclear_features        0x0
+refcount_order            4
+header_length             104
+
+magic                     0x514649fb
+version                   2
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x0
+autoclear_features        0x0
+refcount_order            4
+header_length             72
+
+Header extension:
+magic                     0x6803f857
+length                    144
+data                      <binary>
+
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+=== Testing dirty version downgrade ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x1
+compatible_features       0x1
+autoclear_features        0x0
+refcount_order            4
+header_length             104
+
+Repairing cluster 5 refcount=0 reference=1
+Repairing cluster 6 refcount=0 reference=1
+magic                     0x514649fb
+version                   2
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x0
+autoclear_features        0x0
+refcount_order            4
+header_length             72
+
+Header extension:
+magic                     0x6803f857
+length                    144
+data                      <binary>
+
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+=== Testing version downgrade with unknown compat/autoclear flags ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x40000000000
+autoclear_features        0x40000000000
+refcount_order            4
+header_length             104
+
+magic                     0x514649fb
+version                   2
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x0
+autoclear_features        0x0
+refcount_order            4
+header_length             72
+
+Header extension:
+magic                     0x6803f857
+length                    144
+data                      <binary>
+
+No errors were found on the image.
+
+=== Testing version upgrade and resize ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+wrote 65536/65536 bytes at offset 44040192
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+magic                     0x514649fb
+version                   2
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x0
+autoclear_features        0x0
+refcount_order            4
+header_length             72
+
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      134217728
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x1
+autoclear_features        0x0
+refcount_order            4
+header_length             104
+
+Header extension:
+magic                     0x6803f857
+length                    144
+data                      <binary>
+
+read 65536/65536 bytes at offset 44040192
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+=== Testing dirty lazy_refcounts=off ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x1
+compatible_features       0x1
+autoclear_features        0x0
+refcount_order            4
+header_length             104
+
+Repairing cluster 5 refcount=0 reference=1
+Repairing cluster 6 refcount=0 reference=1
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      67108864
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     0x0
+compatible_features       0x0
+autoclear_features        0x0
+refcount_order            4
+header_length             104
+
+Header extension:
+magic                     0x6803f857
+length                    144
+data                      <binary>
+
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+=== Testing backing file ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+=== Testing invalid configurations ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
+qemu-img: Error while amending options: Invalid argument
+Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
+qemu-img: Error while amending options: Invalid argument
+Unknown compatibility level 0.42.
+qemu-img: Error while amending options: Invalid argument
+Unknown option 'foo'
+qemu-img: Invalid options for file format 'qcow2'
+Changing the cluster size is not supported.
+qemu-img: Error while amending options: Operation not supported
+Changing the encryption flag is not supported.
+qemu-img: Error while amending options: Operation not supported
+Cannot change preallocation mode.
+qemu-img: Error while amending options: Operation not supported
+
+=== Testing correct handling of unset value ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+Should work:
+Should not work:
+Changing the cluster size is not supported.
+qemu-img: Error while amending options: Operation not supported
+
+=== Testing zero expansion on inactive clusters ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Testing zero expansion on backed image ===
+
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file='TEST_DIR/t.IMGFMT.base' 
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Testing zero expansion on backed inactive clusters ===
+
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864 
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file='TEST_DIR/t.IMGFMT.base' 
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+read 131072/131072 bytes at offset 0
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index d46bd6b..ff3b2e6 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -65,4 +65,5 @@
 056 rw auto backing
 059 rw auto
 060 rw auto
+061 rw auto
 062 rw auto
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v5 0/6] block/qcow2: Image file option amendment

[Kevin Wolf]

Am 03.09.2013 um 10:09 hat Max Reitz geschrieben:
> 
> This series adds support to qemu-img, block and qcow2 for amending image
> options on existing image files.
> 
> Depends on:
>  - option: Add assigned flag to QEMUOptionParameter
>  - qcow2-refcount: Snapshot update for zero clusters (series, v3)
>  - Add metadata overlap checks (series, v5)
> 
> v5:
>  - added a new function for emptying a cache (patch 2)
>  - fixed rounding for the bitmap size in qcow2_expand_zero_clusters
>  - now empties the cache in qcow2_expand_zero_clusters instead of simply
>    flushing it
>  - factored out assignment check in qcow2_amend_options
>  - fixed resizing by moving it to the end of qcow2_amend_options
>  - fixed expected test result for resizing in addition to a version
>    upgrade

There's still room for improvements on top, in particular the additional
test cases I suggested in the v4 thread and the real qcow2_truncate()
fix that is just worked around here by moving its call (it needs to
update bs->total_sectors), but this looks good enough to be merged now.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v5 0/6] block/qcow2: Image file option amendment

[Kevin Wolf]

Am 03.09.2013 um 10:09 hat Max Reitz geschrieben:
> 
> This series adds support to qemu-img, block and qcow2 for amending image
> options on existing image files.
> 
> Depends on:
>  - option: Add assigned flag to QEMUOptionParameter
>  - qcow2-refcount: Snapshot update for zero clusters (series, v3)
>  - Add metadata overlap checks (series, v5)

Thanks, applied to the block branch with the following changes:

- Updated patch 5 with
  [PATCH] block/qcow2: Use bdrv_truncate for size amend

- Resolved merge conflict in patch 1 (bdrv_delete -> bdrv_unref)

Kevin