diff options
author | edison <edison@cloud.com> | 2010-09-21 19:58:41 -0700 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2010-10-22 14:49:35 +0200 |
commit | 51ef67270b1d10e1fcf3de7368dccad1ba0bf9d1 (patch) | |
tree | a06b3ce03bae7ed77a1e1e9bebc6ead157c7a4e5 | |
parent | a58b8d5401b6064d52113f243456115d046bdd12 (diff) | |
download | qemu-51ef67270b1d10e1fcf3de7368dccad1ba0bf9d1.zip qemu-51ef67270b1d10e1fcf3de7368dccad1ba0bf9d1.tar.gz qemu-51ef67270b1d10e1fcf3de7368dccad1ba0bf9d1.tar.bz2 |
Copy snapshots out of QCOW2 disk
In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage.
The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img.
Right now, it only supports to copy the full snapshot, delta snapshot is on the way.
Changes from V1: all the comments from Kevin are addressed:
Add read-only checking
Fix coding style
Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp
Signed-off-by: Disheng Su <edison@cloud.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r-- | block.c | 16 | ||||
-rw-r--r-- | block.h | 2 | ||||
-rw-r--r-- | block/qcow2-snapshot.c | 31 | ||||
-rw-r--r-- | block/qcow2.c | 1 | ||||
-rw-r--r-- | block/qcow2.h | 1 | ||||
-rw-r--r-- | block_int.h | 2 | ||||
-rw-r--r-- | qemu-img-cmds.hx | 4 | ||||
-rw-r--r-- | qemu-img.c | 19 | ||||
-rw-r--r-- | qemu-img.texi | 4 |
9 files changed, 75 insertions, 5 deletions
@@ -1899,6 +1899,22 @@ int bdrv_snapshot_list(BlockDriverState *bs, return -ENOTSUP; } +int bdrv_snapshot_load_tmp(BlockDriverState *bs, + const char *snapshot_name) +{ + BlockDriver *drv = bs->drv; + if (!drv) { + return -ENOMEDIUM; + } + if (!bs->read_only) { + return -EINVAL; + } + if (drv->bdrv_snapshot_load_tmp) { + return drv->bdrv_snapshot_load_tmp(bs, snapshot_name); + } + return -ENOTSUP; +} + #define NB_SUFFIXES 4 char *get_human_readable_size(char *buf, int buf_size, int64_t size) @@ -211,6 +211,8 @@ int bdrv_snapshot_goto(BlockDriverState *bs, int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info); +int bdrv_snapshot_load_tmp(BlockDriverState *bs, + const char *snapshot_name); char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn); char *get_human_readable_size(char *buf, int buf_size, int64_t size); diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 8dd5df0..aacf357 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -418,3 +418,34 @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab) return s->nb_snapshots; } +int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name) +{ + int i, snapshot_index, l1_size2; + BDRVQcowState *s = bs->opaque; + QCowSnapshot *sn; + + snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_name); + if (snapshot_index < 0) { + return -ENOENT; + } + + sn = &s->snapshots[snapshot_index]; + s->l1_size = sn->l1_size; + l1_size2 = s->l1_size * sizeof(uint64_t); + if (s->l1_table != NULL) { + qemu_free(s->l1_table); + } + + s->l1_table_offset = sn->l1_table_offset; + s->l1_table = qemu_mallocz(align_offset(l1_size2, 512)); + + if (bdrv_pread(bs->file, sn->l1_table_offset, + s->l1_table, l1_size2) != l1_size2) { + return -1; + } + + for(i = 0;i < s->l1_size; i++) { + be64_to_cpus(&s->l1_table[i]); + } + return 0; +} diff --git a/block/qcow2.c b/block/qcow2.c index 45ed073..b816d87 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1286,6 +1286,7 @@ static BlockDriver bdrv_qcow2 = { .bdrv_snapshot_goto = qcow2_snapshot_goto, .bdrv_snapshot_delete = qcow2_snapshot_delete, .bdrv_snapshot_list = qcow2_snapshot_list, + .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, .bdrv_get_info = qcow_get_info, .bdrv_save_vmstate = qcow_save_vmstate, diff --git a/block/qcow2.h b/block/qcow2.h index add710b..2d22e5e 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -211,6 +211,7 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); +int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name); void qcow2_free_snapshots(BlockDriverState *bs); int qcow2_read_snapshots(BlockDriverState *bs); diff --git a/block_int.h b/block_int.h index e8e7156..87e60b8 100644 --- a/block_int.h +++ b/block_int.h @@ -93,6 +93,8 @@ struct BlockDriver { int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id); int (*bdrv_snapshot_list)(BlockDriverState *bs, QEMUSnapshotInfo **psn_info); + int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, + const char *snapshot_name); int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf, diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index 6d3e5f8..6c7176f 100644 --- a/qemu-img-cmds.hx +++ b/qemu-img-cmds.hx @@ -28,9 +28,9 @@ STEXI ETEXI DEF("convert", img_convert, - "convert [-c] [-f fmt] [-O output_fmt] [-o options] filename [filename2 [...]] output_filename") + "convert [-c] [-f fmt] [-O output_fmt] [-o options] [-s snapshot_name] filename [filename2 [...]] output_filename") STEXI -@item convert [-c] [-f @var{fmt}] [-O @var{output_fmt}] [-o @var{options}] @var{filename} [@var{filename2} [...]] @var{output_filename} +@item convert [-c] [-f @var{fmt}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_name}] @var{filename} [@var{filename2} [...]] @var{output_filename} ETEXI DEF("info", img_info, @@ -646,13 +646,14 @@ static int img_convert(int argc, char **argv) BlockDriverInfo bdi; QEMUOptionParameter *param = NULL, *create_options = NULL; char *options = NULL; + const char *snapshot_name = NULL; fmt = NULL; out_fmt = "raw"; out_baseimg = NULL; flags = 0; for(;;) { - c = getopt(argc, argv, "f:O:B:hce6o:"); + c = getopt(argc, argv, "f:O:B:s:hce6o:"); if (c == -1) break; switch(c) { @@ -680,6 +681,9 @@ static int img_convert(int argc, char **argv) case 'o': options = optarg; break; + case 's': + snapshot_name = optarg; + break; } } @@ -711,6 +715,19 @@ static int img_convert(int argc, char **argv) total_sectors += bs_sectors; } + if (snapshot_name != NULL) { + if (bs_n > 1) { + error("No support for concatenating multiple snapshot\n"); + ret = -1; + goto out; + } + if (bdrv_snapshot_load_tmp(bs[0], snapshot_name) < 0) { + error("Failed to load snapshot\n"); + ret = -1; + goto out; + } + } + /* Find driver and parse its options */ drv = bdrv_find_format(out_fmt); if (!drv) { diff --git a/qemu-img.texi b/qemu-img.texi index c1b1f27..1b90ddb 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -77,9 +77,9 @@ it doesn't need to be specified separately in this case. Commit the changes recorded in @var{filename} in its base image. -@item convert [-c] [-f @var{fmt}] [-O @var{output_fmt}] [-o @var{options}] @var{filename} [@var{filename2} [...]] @var{output_filename} +@item convert [-c] [-f @var{fmt}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_name}] @var{filename} [@var{filename2} [...]] @var{output_filename} -Convert the disk image @var{filename} to disk image @var{output_filename} +Convert the disk image @var{filename} or a snapshot @var{snapshot_name} to disk image @var{output_filename} using format @var{output_fmt}. It can be optionally compressed (@code{-c} option) or use any format specific options like encryption (@code{-o} option). |