From f30c66ba6e417a07e68ad6e0bc5da27561a3beea Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 1 Feb 2019 20:29:05 +0100 Subject: block: Use bdrv_refresh_filename() to pull Before this patch, bdrv_refresh_filename() is used in a pushing manner: Whenever the BDS graph is modified, the parents of the modified edges are supposed to be updated (recursively upwards). However, that is nonviable, considering that we want child changes not to concern parents. Also, in the long run we want a pull model anyway: Here, we would have a bdrv_filename() function which returns a BDS's filename, freshly constructed. This patch is an intermediate step. It adds bdrv_refresh_filename() calls before every place a BDS.filename value is used. The only exceptions are protocol drivers that use their own filename, which clearly would not profit from refreshing that filename before. Also, bdrv_get_encrypted_filename() is removed along the way (as a user of BDS.filename), since it is completely unused. In turn, all of the calls to bdrv_refresh_filename() before this patch are removed, because we no longer have to call this function on graph changes. Signed-off-by: Max Reitz Message-id: 20190201192935.18394-2-mreitz@redhat.com Reviewed-by: Eric Blake Signed-off-by: Max Reitz --- blockdev.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'blockdev.c') diff --git a/blockdev.c b/blockdev.c index 8714ad2..7e6bf99 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1627,6 +1627,7 @@ static void external_snapshot_prepare(BlkActionState *common, error_setg_errno(errp, -size, "bdrv_getlength failed"); goto out; } + bdrv_refresh_filename(state->old_bs); bdrv_img_create(new_image_file, format, state->old_bs->filename, state->old_bs->drv->format_name, @@ -3230,6 +3231,7 @@ void qmp_block_stream(bool has_job_id, const char *job_id, const char *device, goto out; } assert(bdrv_get_aio_context(base_bs) == aio_context); + bdrv_refresh_filename(base_bs); base_name = base_bs->filename; } @@ -3349,6 +3351,10 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, goto out; } } else if (has_top && top) { + /* This strcmp() is just a shortcut, there is no need to + * refresh @bs's filename. If it mismatches, + * bdrv_find_backing_image() will do the refresh and may still + * return @bs. */ if (strcmp(bs->filename, top) != 0) { top_bs = bdrv_find_backing_image(bs, top); } @@ -3509,6 +3515,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn, if (backup->mode != NEW_IMAGE_MODE_EXISTING) { assert(backup->format); if (source) { + bdrv_refresh_filename(source); bdrv_img_create(backup->target, backup->format, source->filename, source->drv->format_name, NULL, size, flags, false, &local_err); @@ -3889,6 +3896,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) break; case NEW_IMAGE_MODE_ABSOLUTE_PATHS: /* create new image with backing file */ + bdrv_refresh_filename(source); bdrv_img_create(arg->target, format, source->filename, source->drv->format_name, -- cgit v1.1