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[Qemu-devel] [PATCH 08/32] qemu-img: Add --backing-chain option to info
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 08/32] qemu-img: Add --backing-chain option to info command |
Date: |
Wed, 24 Oct 2012 11:50:32 +0200 |
From: Stefan Hajnoczi <address@hidden>
The qemu-img info --backing-chain option enumerates the backing file
chain. For example, for base.qcow2 <- snap1.qcow2 <- snap2.qcow2 the
output becomes:
$ qemu-img info --backing-chain snap2.qcow2
image: snap2.qcow2
file format: qcow2
virtual size: 100M (104857600 bytes)
disk size: 196K
cluster_size: 65536
backing file: snap1.qcow2
backing file format: qcow2
image: snap1.qcow2
file format: qcow2
virtual size: 100M (104857600 bytes)
disk size: 196K
cluster_size: 65536
backing file: base.qcow2
backing file format: qcow2
image: base.qcow2
file format: qcow2
virtual size: 100M (104857600 bytes)
disk size: 136K
cluster_size: 65536
Signed-off-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
qemu-img.c | 167 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 153 insertions(+), 14 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index c092ccf..b17bddd 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1112,6 +1112,23 @@ static void dump_snapshots(BlockDriverState *bs)
g_free(sn_tab);
}
+static void dump_json_image_info_list(ImageInfoList *list)
+{
+ Error *errp = NULL;
+ QString *str;
+ QmpOutputVisitor *ov = qmp_output_visitor_new();
+ QObject *obj;
+ visit_type_ImageInfoList(qmp_output_get_visitor(ov),
+ &list, NULL, &errp);
+ obj = qmp_output_get_qobject(ov);
+ str = qobject_to_json_pretty(obj);
+ assert(str != NULL);
+ printf("%s\n", qstring_get_str(str));
+ qobject_decref(obj);
+ qmp_output_visitor_cleanup(ov);
+ QDECREF(str);
+}
+
static void collect_snapshots(BlockDriverState *bs , ImageInfo *info)
{
int i, sn_count;
@@ -1251,9 +1268,129 @@ static void dump_human_image_info(ImageInfo *info)
printf("backing file format: %s\n", info->backing_filename_format);
}
}
+
+ if (info->has_snapshots) {
+ SnapshotInfoList *elem;
+ char buf[256];
+
+ printf("Snapshot list:\n");
+ printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
+
+ /* Ideally bdrv_snapshot_dump() would operate on SnapshotInfoList but
+ * we convert to the block layer's native QEMUSnapshotInfo for now.
+ */
+ for (elem = info->snapshots; elem; elem = elem->next) {
+ QEMUSnapshotInfo sn = {
+ .vm_state_size = elem->value->vm_state_size,
+ .date_sec = elem->value->date_sec,
+ .date_nsec = elem->value->date_nsec,
+ .vm_clock_nsec = elem->value->vm_clock_sec * 1000000000ULL +
+ elem->value->vm_clock_nsec,
+ };
+
+ pstrcpy(sn.id_str, sizeof(sn.id_str), elem->value->id);
+ pstrcpy(sn.name, sizeof(sn.name), elem->value->name);
+ printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), &sn));
+ }
+ }
+}
+
+static void dump_human_image_info_list(ImageInfoList *list)
+{
+ ImageInfoList *elem;
+ bool delim = false;
+
+ for (elem = list; elem; elem = elem->next) {
+ if (delim) {
+ printf("\n");
+ }
+ delim = true;
+
+ dump_human_image_info(elem->value);
+ }
+}
+
+static gboolean str_equal_func(gconstpointer a, gconstpointer b)
+{
+ return strcmp(a, b) == 0;
+}
+
+/**
+ * Open an image file chain and return an ImageInfoList
+ *
+ * @filename: topmost image filename
+ * @fmt: topmost image format (may be NULL to autodetect)
+ * @chain: true - enumerate entire backing file chain
+ * false - only topmost image file
+ *
+ * Returns a list of ImageInfo objects or NULL if there was an error opening an
+ * image file. If there was an error a message will have been printed to
+ * stderr.
+ */
+static ImageInfoList *collect_image_info_list(const char *filename,
+ const char *fmt,
+ bool chain)
+{
+ ImageInfoList *head = NULL;
+ ImageInfoList **last = &head;
+ GHashTable *filenames;
+
+ filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL, NULL);
+
+ while (filename) {
+ BlockDriverState *bs;
+ ImageInfo *info;
+ ImageInfoList *elem;
+
+ if (g_hash_table_lookup_extended(filenames, filename, NULL, NULL)) {
+ error_report("Backing file '%s' creates an infinite loop.",
+ filename);
+ goto err;
+ }
+ g_hash_table_insert(filenames, (gpointer)filename, NULL);
+
+ bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING,
+ false);
+ if (!bs) {
+ goto err;
+ }
+
+ info = g_new0(ImageInfo, 1);
+ collect_image_info(bs, info, filename, fmt);
+ collect_snapshots(bs, info);
+
+ elem = g_new0(ImageInfoList, 1);
+ elem->value = info;
+ *last = elem;
+ last = &elem->next;
+
+ bdrv_delete(bs);
+
+ filename = fmt = NULL;
+ if (chain) {
+ if (info->has_full_backing_filename) {
+ filename = info->full_backing_filename;
+ } else if (info->has_backing_filename) {
+ filename = info->backing_filename;
+ }
+ if (info->has_backing_filename_format) {
+ fmt = info->backing_filename_format;
+ }
+ }
+ }
+ g_hash_table_destroy(filenames);
+ return head;
+
+err:
+ qapi_free_ImageInfoList(head);
+ g_hash_table_destroy(filenames);
+ return NULL;
}
-enum {OPTION_OUTPUT = 256};
+enum {
+ OPTION_OUTPUT = 256,
+ OPTION_BACKING_CHAIN = 257,
+};
typedef enum OutputFormat {
OFORMAT_JSON,
@@ -1264,9 +1401,9 @@ static int img_info(int argc, char **argv)
{
int c;
OutputFormat output_format = OFORMAT_HUMAN;
+ bool chain = false;
const char *filename, *fmt, *output;
- BlockDriverState *bs;
- ImageInfo *info;
+ ImageInfoList *list;
fmt = NULL;
output = NULL;
@@ -1276,6 +1413,7 @@ static int img_info(int argc, char **argv)
{"help", no_argument, 0, 'h'},
{"format", required_argument, 0, 'f'},
{"output", required_argument, 0, OPTION_OUTPUT},
+ {"backing-chain", no_argument, 0, OPTION_BACKING_CHAIN},
{0, 0, 0, 0}
};
c = getopt_long(argc, argv, "f:h",
@@ -1294,6 +1432,9 @@ static int img_info(int argc, char **argv)
case OPTION_OUTPUT:
output = optarg;
break;
+ case OPTION_BACKING_CHAIN:
+ chain = true;
+ break;
}
}
if (optind >= argc) {
@@ -1310,27 +1451,25 @@ static int img_info(int argc, char **argv)
return 1;
}
- bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING, false);
- if (!bs) {
+ list = collect_image_info_list(filename, fmt, chain);
+ if (!list) {
return 1;
}
- info = g_new0(ImageInfo, 1);
- collect_image_info(bs, info, filename, fmt);
-
switch (output_format) {
case OFORMAT_HUMAN:
- dump_human_image_info(info);
- dump_snapshots(bs);
+ dump_human_image_info_list(list);
break;
case OFORMAT_JSON:
- collect_snapshots(bs, info);
- dump_json_image_info(info);
+ if (chain) {
+ dump_json_image_info_list(list);
+ } else {
+ dump_json_image_info(list->value);
+ }
break;
}
- qapi_free_ImageInfo(info);
- bdrv_delete(bs);
+ qapi_free_ImageInfoList(list);
return 0;
}
--
1.7.6.5
- [Qemu-devel] [PULL 00/32] Block patches, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 01/32] qemu-img: Fix division by zero for zero size images, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 02/32] qemu-iotests: Test qemu-img operation on zero size image, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 05/32] block: make bdrv_find_backing_image compare canonical filenames, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 03/32] qmp: fix __accept() in qmp.py, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 07/32] qemu-iotests: add relative backing file tests for block-commit (040), Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 04/32] qemu-img rebase: use empty string to rebase without backing file, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 08/32] qemu-img: Add --backing-chain option to info command,
Kevin Wolf <=
- [Qemu-devel] [PATCH 06/32] block: in commit, determine base image from the top image, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 12/32] monitor: Allow add-fd to any specified fd set, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 10/32] qemu-img: document 'info --backing-chain', Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 11/32] block: bdrv_create(): don't leak cco.filename on error, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 14/32] monitor: Prevent removing fd from set during init, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 09/32] qemu-iotests: Add 043 backing file chain infinite loop test, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 17/32] block: add bdrv_query_stats, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 15/32] qemu-config: Add new -add-fd command line option, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 19/32] block: introduce new dirty bitmap functionality, Kevin Wolf, 2012/10/24
- [Qemu-devel] [PATCH 21/32] block: rename block_job_complete to block_job_completed, Kevin Wolf, 2012/10/24