block: Add bdrv_set_backing_hd()
This is the common but non-trivial steps to assign or change the backing_hd of BDS. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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parent
628ff68303
commit
8d24cce1e3
36
block.c
36
block.c
@ -1094,6 +1094,21 @@ fail:
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return ret;
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}
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void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
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{
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bs->backing_hd = backing_hd;
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if (!backing_hd) {
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goto out;
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}
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bs->open_flags &= ~BDRV_O_NO_BACKING;
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pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
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pstrcpy(bs->backing_format, sizeof(bs->backing_format),
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backing_hd->drv ? backing_hd->drv->format_name : "");
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out:
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bdrv_refresh_limits(bs);
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}
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/*
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* Opens the backing file for a BlockDriverState if not yet open
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*
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@ -1107,6 +1122,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
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char *backing_filename = g_malloc0(PATH_MAX);
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int ret = 0;
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BlockDriver *back_drv = NULL;
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BlockDriverState *backing_hd;
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Error *local_err = NULL;
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if (bs->backing_hd != NULL) {
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@ -1129,27 +1145,26 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
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bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX);
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}
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backing_hd = bdrv_new("", errp);
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if (bs->backing_format[0] != '\0') {
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back_drv = bdrv_find_format(bs->backing_format);
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}
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assert(bs->backing_hd == NULL);
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ret = bdrv_open(&bs->backing_hd,
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ret = bdrv_open(&backing_hd,
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*backing_filename ? backing_filename : NULL, NULL, options,
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bdrv_backing_flags(bs->open_flags), back_drv, &local_err);
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if (ret < 0) {
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bs->backing_hd = NULL;
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bdrv_unref(backing_hd);
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backing_hd = NULL;
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bs->open_flags |= BDRV_O_NO_BACKING;
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error_setg(errp, "Could not open backing file: %s",
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error_get_pretty(local_err));
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error_free(local_err);
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goto free_exit;
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}
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if (bs->backing_hd->file) {
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pstrcpy(bs->backing_file, sizeof(bs->backing_file),
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bs->backing_hd->file->filename);
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}
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bdrv_set_backing_hd(bs, backing_hd);
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/* Recalculate the BlockLimits with the backing file */
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bdrv_refresh_limits(bs);
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@ -2043,12 +2058,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
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/* The contents of 'tmp' will become bs_top, as we are
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* swapping bs_new and bs_top contents. */
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bs_top->backing_hd = bs_new;
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bs_top->open_flags &= ~BDRV_O_NO_BACKING;
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pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file),
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bs_new->filename);
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pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format),
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bs_new->drv ? bs_new->drv->format_name : "");
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bdrv_set_backing_hd(bs_top, bs_new);
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}
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static void bdrv_delete(BlockDriverState *bs)
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@ -216,6 +216,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags);
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int bdrv_open_image(BlockDriverState **pbs, const char *filename,
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QDict *options, const char *bdref_key, int flags,
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bool allow_none, Error **errp);
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void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
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int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp);
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void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp);
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int bdrv_open(BlockDriverState **pbs, const char *filename,
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