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authorEyal Moscovici <eyal.moscovici@oracle.com>2020-05-13 16:36:29 +0300
committerEric Blake <eblake@redhat.com>2020-05-18 11:02:05 -0500
commitc0469496b32910a6a092d5b614efbf4088b13a29 (patch)
tree99e8482168bbb8ec2448c338db2bebe08780c2a9 /qemu-img.c
parente46c0b18cfd02195a0d527ca73f3ed9f3ce5eacb (diff)
qemu-img: Add --start-offset and --max-length to map
The mapping operation of large disks especially ones stored over a long chain of QCOW2 files can take a long time to finish. Additionally when mapping fails there was no way recover by restarting the mapping from the failed location. The new options, --start-offset and --max-length allows the user to divide these type of map operations into shorter independent tasks. Reviewed-by: Eric Blake <eblake@redhat.com> Acked-by: Mark Kanda <mark.kanda@oracle.com> Co-developed-by: Yoav Elnekave <yoav.elnekave@oracle.com> Signed-off-by: Yoav Elnekave <yoav.elnekave@oracle.com> Signed-off-by: Eyal Moscovici <eyal.moscovici@oracle.com> Message-Id: <20200513133629.18508-5-eyal.moscovici@oracle.com> Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'qemu-img.c')
-rw-r--r--qemu-img.c22
1 files changed, 21 insertions, 1 deletions
diff --git a/qemu-img.c b/qemu-img.c
index 4aa9414aba..947bf8b34b 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3009,6 +3009,8 @@ static int img_map(int argc, char **argv)
int ret = 0;
bool image_opts = false;
bool force_share = false;
+ int64_t start_offset = 0;
+ int64_t max_length = -1;
fmt = NULL;
output = NULL;
@@ -3021,9 +3023,11 @@ static int img_map(int argc, char **argv)
{"object", required_argument, 0, OPTION_OBJECT},
{"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
{"force-share", no_argument, 0, 'U'},
+ {"start-offset", required_argument, 0, 's'},
+ {"max-length", required_argument, 0, 'l'},
{0, 0, 0, 0}
};
- c = getopt_long(argc, argv, ":f:hU",
+ c = getopt_long(argc, argv, ":f:s:l:hU",
long_options, &option_index);
if (c == -1) {
break;
@@ -3047,6 +3051,18 @@ static int img_map(int argc, char **argv)
case OPTION_OUTPUT:
output = optarg;
break;
+ case 's':
+ start_offset = cvtnum("start offset", optarg);
+ if (start_offset < 0) {
+ return 1;
+ }
+ break;
+ case 'l':
+ max_length = cvtnum("max length", optarg);
+ if (max_length < 0) {
+ return 1;
+ }
+ break;
case OPTION_OBJECT: {
QemuOpts *opts;
opts = qemu_opts_parse_noisily(&qemu_object_opts,
@@ -3097,7 +3113,11 @@ static int img_map(int argc, char **argv)
error_report("Failed to get size for '%s'", filename);
return 1;
}
+ if (max_length != -1) {
+ length = MIN(start_offset + max_length, length);
+ }
+ curr.start = start_offset;
while (curr.start + curr.length < length) {
int64_t offset = curr.start + curr.length;
int64_t n;