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authorMax Reitz <mreitz@redhat.com>2015-02-18 17:40:49 -0500
committerKevin Wolf <kwolf@redhat.com>2015-03-10 14:02:21 +0100
commit06d05fa738915ab82577289a0b81b3e600c4e749 (patch)
tree23436e6bf7bf8e9feb11afd7eedd2ab9b19ab404 /block/qcow2.c
parent5262caa75468adce44b57ed9c076b2f22bd9315f (diff)
qcow2: Allow creation with refcount order != 4
Add a creation option to qcow2 for setting the refcount order of images to be created, and respect that option's value. This breaks some test outputs, fix them. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/qcow2.c')
-rw-r--r--block/qcow2.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 64bb7b8a1f..8bfb094e53 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2079,6 +2079,15 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp)
goto finish;
}
+ refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS,
+ refcount_bits);
+ if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) {
+ error_setg(errp, "Refcount width must be a power of two and may not "
+ "exceed 64 bits");
+ ret = -EINVAL;
+ goto finish;
+ }
+
if (version < 3 && refcount_bits != 16) {
error_setg(errp, "Different refcount widths than 16 bits require "
"compatibility level 1.1 or above (use compat=1.1 or "
@@ -2712,6 +2721,9 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
} else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) {
lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS,
lazy_refcounts);
+ } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) {
+ error_report("Cannot change refcount entry width");
+ return -ENOTSUP;
} else {
/* if this assertion fails, this probably means a new option was
* added without having it covered here */
@@ -2881,6 +2893,12 @@ static QemuOptsList qcow2_create_opts = {
.help = "Postpone refcount updates",
.def_value_str = "off"
},
+ {
+ .name = BLOCK_OPT_REFCOUNT_BITS,
+ .type = QEMU_OPT_NUMBER,
+ .help = "Width of a reference count entry in bits",
+ .def_value_str = "16"
+ },
{ /* end of list */ }
}
};