| Message ID | 1350305057-6287-2-git-send-email-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
Am 15.10.2012 14:44, schrieb Stefan Hajnoczi: > 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 <stefanha@redhat.com> > --- > qemu-img.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 76 insertions(+), 22 deletions(-) > > diff --git a/qemu-img.c b/qemu-img.c > index f17f187..c717f3e 100644 > --- a/qemu-img.c > +++ b/qemu-img.c > @@ -1249,7 +1249,10 @@ static void dump_human_image_info(ImageInfo *info) > } > } > > -enum {OPTION_OUTPUT = 256}; > +enum { > + OPTION_OUTPUT = 256, > + OPTION_BACKING_CHAIN = 257, > +}; > > typedef enum OutputFormat { > OFORMAT_JSON, > @@ -1260,7 +1263,9 @@ static int img_info(int argc, char **argv) > { > int c; > OutputFormat output_format = OFORMAT_HUMAN; > - const char *filename, *fmt, *output; > + bool chain = false; > + const char *output; > + char *filename, *fmt; Maybe I'm missing something, but where are the strings pointed at by filename and fmt ever modified? If they aren't, strdup() isn't necessary either. Kevin
On Tue, Oct 16, 2012 at 12:04:24PM +0200, Kevin Wolf wrote: > Am 15.10.2012 14:44, schrieb Stefan Hajnoczi: > > 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 <stefanha@redhat.com> > > --- > > qemu-img.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++-------------- > > 1 file changed, 76 insertions(+), 22 deletions(-) > > > > diff --git a/qemu-img.c b/qemu-img.c > > index f17f187..c717f3e 100644 > > --- a/qemu-img.c > > +++ b/qemu-img.c > > @@ -1249,7 +1249,10 @@ static void dump_human_image_info(ImageInfo *info) > > } > > } > > > > -enum {OPTION_OUTPUT = 256}; > > +enum { > > + OPTION_OUTPUT = 256, > > + OPTION_BACKING_CHAIN = 257, > > +}; > > > > typedef enum OutputFormat { > > OFORMAT_JSON, > > @@ -1260,7 +1263,9 @@ static int img_info(int argc, char **argv) > > { > > int c; > > OutputFormat output_format = OFORMAT_HUMAN; > > - const char *filename, *fmt, *output; > > + bool chain = false; > > + const char *output; > > + char *filename, *fmt; > > Maybe I'm missing something, but where are the strings pointed at by > filename and fmt ever modified? If they aren't, strdup() isn't necessary > either. It's necessary because the loop strdups the current image's backing file, then frees the current image info (including the original backing file string). To avoid special cases for the topmost image filename/fmt we just strdup them. Stefan
diff --git a/qemu-img.c b/qemu-img.c index f17f187..c717f3e 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1249,7 +1249,10 @@ static void dump_human_image_info(ImageInfo *info) } } -enum {OPTION_OUTPUT = 256}; +enum { + OPTION_OUTPUT = 256, + OPTION_BACKING_CHAIN = 257, +}; typedef enum OutputFormat { OFORMAT_JSON, @@ -1260,7 +1263,9 @@ static int img_info(int argc, char **argv) { int c; OutputFormat output_format = OFORMAT_HUMAN; - const char *filename, *fmt, *output; + bool chain = false; + const char *output; + char *filename, *fmt; BlockDriverState *bs; ImageInfo *info; @@ -1272,6 +1277,7 @@ 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", @@ -1285,17 +1291,20 @@ static int img_info(int argc, char **argv) help(); break; case 'f': - fmt = optarg; + fmt = g_strdup(optarg); break; case OPTION_OUTPUT: output = optarg; break; + case OPTION_BACKING_CHAIN: + chain = true; + break; } } if (optind >= argc) { help(); } - filename = argv[optind++]; + filename = g_strdup(argv[optind++]); if (output && !strcmp(output, "json")) { output_format = OFORMAT_JSON; @@ -1303,31 +1312,76 @@ static int img_info(int argc, char **argv) output_format = OFORMAT_HUMAN; } else if (output) { error_report("--output must be used with human or json as argument."); - return 1; + goto err; } - bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING, false); - if (!bs) { - return 1; + if (chain && output_format == OFORMAT_JSON) { + printf("[\n"); } - info = g_new0(ImageInfo, 1); - collect_image_info(bs, info, filename, fmt); + do { + bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING, + false); + if (!bs) { + goto err; + } - switch (output_format) { - case OFORMAT_HUMAN: - dump_human_image_info(info); - dump_snapshots(bs); - break; - case OFORMAT_JSON: - collect_snapshots(bs, info); - dump_json_image_info(info); - break; - } + info = g_new0(ImageInfo, 1); + collect_image_info(bs, info, filename, fmt); - qapi_free_ImageInfo(info); - bdrv_delete(bs); + switch (output_format) { + case OFORMAT_HUMAN: + dump_human_image_info(info); + dump_snapshots(bs); + break; + case OFORMAT_JSON: + collect_snapshots(bs, info); + dump_json_image_info(info); + break; + } + + g_free(filename); + g_free(fmt); + filename = NULL; + fmt = NULL; + + if (chain) { + if (info->has_full_backing_filename) { + filename = g_strdup(info->full_backing_filename); + } else if (info->has_backing_filename) { + filename = g_strdup(info->backing_filename); + } + + if (filename && info->has_backing_filename_format) { + fmt = g_strdup(info->backing_filename_format); + } + + /* Print delimiters between items */ + if (filename) { + switch (output_format) { + case OFORMAT_HUMAN: + printf("\n"); + break; + case OFORMAT_JSON: + printf(",\n"); + break; + } + } + } + + qapi_free_ImageInfo(info); + bdrv_delete(bs); + } while (filename); + + if (chain && output_format == OFORMAT_JSON) { + printf("]\n"); + } return 0; + +err: + g_free(filename); + g_free(fmt); + return 1; } #define SNAPSHOT_LIST 1
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 <stefanha@redhat.com> --- qemu-img.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 76 insertions(+), 22 deletions(-)