From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60400) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fntT3-000841-Qc for qemu-devel@nongnu.org; Thu, 09 Aug 2018 18:31:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fntT1-0002hN-6A for qemu-devel@nongnu.org; Thu, 09 Aug 2018 18:31:41 -0400 From: Max Reitz Date: Fri, 10 Aug 2018 00:31:10 +0200 Message-Id: <20180809223117.7846-5-mreitz@redhat.com> In-Reply-To: <20180809223117.7846-1-mreitz@redhat.com> References: <20180809223117.7846-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v2 04/11] block: Storage child access function List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Kevin Wolf For completeness' sake, add a function for accessing a node's storage child, too. For filters, this is there filtered child; for non-filters, this is bs->file. Some places are deliberately left unconverted: - BDS opening/closing functions where bs->file is handled specially (which is basically wrong, but at least simplifies probing) - bdrv_co_block_status_from_file(), because its name implies that it points to ->file - bdrv_snapshot_goto() in one places unrefs bs->file. Such a modification is not covered by this patch and is therefore just safeguarded by an additional assert(), but otherwise kept as-is. Signed-off-by: Max Reitz --- include/block/block_int.h | 6 +++++ block.c | 51 ++++++++++++++++++++++++++++----------- block/io.c | 20 +++++++++------ block/qapi.c | 7 +++--- block/snapshot.c | 40 +++++++++++++++++------------- 5 files changed, 82 insertions(+), 42 deletions(-) diff --git a/include/block/block_int.h b/include/block/block_int.h index fa9154899d..d3d8b22155 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -1214,6 +1214,7 @@ int refresh_total_sectors(BlockDriverState *bs, int64_t hint); BdrvChild *bdrv_filtered_cow_child(BlockDriverState *bs); BdrvChild *bdrv_filtered_rw_child(BlockDriverState *bs); BdrvChild *bdrv_filtered_child(BlockDriverState *bs); +BdrvChild *bdrv_storage_child(BlockDriverState *bs); BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs); BlockDriverState *bdrv_skip_rw_filters(BlockDriverState *bs); BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs); @@ -1238,4 +1239,9 @@ static inline BlockDriverState *bdrv_filtered_bs(BlockDriverState *bs) return child_bs(bdrv_filtered_child(bs)); } +static inline BlockDriverState *bdrv_storage_bs(BlockDriverState *bs) +{ + return child_bs(bdrv_storage_child(bs)); +} + #endif /* BLOCK_INT_H */ diff --git a/block.c b/block.c index 61a2fe14eb..a3a121551a 100644 --- a/block.c +++ b/block.c @@ -3835,15 +3835,21 @@ exit: int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs; + if (!drv) { return -ENOMEDIUM; } + if (drv->bdrv_get_allocated_file_size) { return drv->bdrv_get_allocated_file_size(bs); } - if (bs->file) { - return bdrv_get_allocated_file_size(bs->file->bs); + + storage_bs = bdrv_storage_bs(bs); + if (storage_bs) { + return bdrv_get_allocated_file_size(storage_bs); } + return -ENOTSUP; } @@ -4252,7 +4258,7 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, const char *tag) { while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { - bs = bs->file ? bs->file->bs : NULL; + bs = bdrv_storage_bs(bs); } if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { @@ -4265,7 +4271,7 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) { while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { - bs = bs->file ? bs->file->bs : NULL; + bs = bdrv_storage_bs(bs); } if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { @@ -4278,7 +4284,7 @@ int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) int bdrv_debug_resume(BlockDriverState *bs, const char *tag) { while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { - bs = bs->file ? bs->file->bs : NULL; + bs = bdrv_storage_bs(bs); } if (bs && bs->drv && bs->drv->bdrv_debug_resume) { @@ -4291,7 +4297,7 @@ int bdrv_debug_resume(BlockDriverState *bs, const char *tag) bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) { while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { - bs = bs->file ? bs->file->bs : NULL; + bs = bdrv_storage_bs(bs); } if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { @@ -5388,14 +5394,21 @@ void bdrv_refresh_filename(BlockDriverState *bs) bs->exact_filename[0] = '\0'; drv->bdrv_refresh_filename(bs); - } else if (bs->file) { - /* Try to reconstruct valid information from the underlying file */ + } else if (bdrv_storage_child(bs)) { + /* Try to reconstruct valid information from the underlying + * file -- this only works for format nodes (filter nodes + * cannot be probed and as such must be selected by the user + * either through an options dict, or through a special + * filename which the filter driver must construct in its + * .bdrv_refresh_filename() implementation) */ + BlockDriverState *storage_bs = bdrv_storage_bs(bs); bs->exact_filename[0] = '\0'; /* * We can use the underlying file's filename if: * - it has a filename, + * - the current BDS is not a filter, * - the file is a protocol BDS, and * - opening that file (as this BDS's format) will automatically create * the BDS tree we have right now, that is: @@ -5404,11 +5417,10 @@ void bdrv_refresh_filename(BlockDriverState *bs) * - no non-file child of this BDS has been overridden by the user * Both of these conditions are represented by generate_json_filename. */ - if (bs->file->bs->exact_filename[0] && - bs->file->bs->drv->bdrv_file_open && - !generate_json_filename) + if (storage_bs->exact_filename[0] && storage_bs->drv->bdrv_file_open && + !drv->is_filter && !generate_json_filename) { - strcpy(bs->exact_filename, bs->file->bs->exact_filename); + strcpy(bs->exact_filename, storage_bs->exact_filename); } } @@ -5425,6 +5437,7 @@ void bdrv_refresh_filename(BlockDriverState *bs) char *bdrv_dirname(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs; if (!drv) { error_setg(errp, "Node '%s' is ejected", bs->node_name); @@ -5435,8 +5448,9 @@ char *bdrv_dirname(BlockDriverState *bs, Error **errp) return drv->bdrv_dirname(bs, errp); } - if (bs->file) { - return bdrv_dirname(bs->file->bs, errp); + storage_bs = bdrv_storage_bs(bs); + if (storage_bs) { + return bdrv_dirname(storage_bs, errp); } bdrv_refresh_filename(bs); @@ -5570,6 +5584,15 @@ BdrvChild *bdrv_filtered_child(BlockDriverState *bs) return cow_child ?: rw_child; } +/* + * Return the child that stores the data that is allocated on this + * node. This may or may not include metadata. + */ +BdrvChild *bdrv_storage_child(BlockDriverState *bs) +{ + return bdrv_filtered_rw_child(bs) ?: bs->file; +} + static BlockDriverState *bdrv_skip_filters(BlockDriverState *bs, bool stop_on_explicit_filter) { diff --git a/block/io.c b/block/io.c index 8a442d37b2..7fb81287c5 100644 --- a/block/io.c +++ b/block/io.c @@ -120,6 +120,7 @@ static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src) void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs = bdrv_storage_bs(bs); BlockDriverState *cow_bs = bdrv_filtered_cow_bs(bs); Error *local_err = NULL; @@ -134,13 +135,13 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) drv->bdrv_aio_preadv) ? 1 : 512; /* Take some limits from the children as a default */ - if (bs->file) { - bdrv_refresh_limits(bs->file->bs, &local_err); + if (storage_bs) { + bdrv_refresh_limits(storage_bs, &local_err); if (local_err) { error_propagate(errp, local_err); return; } - bdrv_merge_limits(&bs->bl, &bs->file->bs->bl); + bdrv_merge_limits(&bs->bl, &storage_bs->bl); } else { bs->bl.min_mem_alignment = 512; bs->bl.opt_mem_alignment = getpagesize(); @@ -2412,6 +2413,7 @@ bdrv_co_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos, bool is_read) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs = bdrv_storage_bs(bs); int ret = -ENOTSUP; bdrv_inc_in_flight(bs); @@ -2424,8 +2426,8 @@ bdrv_co_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos, } else { ret = drv->bdrv_save_vmstate(bs, qiov, pos); } - } else if (bs->file) { - ret = bdrv_co_rw_vmstate(bs->file->bs, qiov, pos, is_read); + } else if (storage_bs) { + ret = bdrv_co_rw_vmstate(storage_bs, qiov, pos, is_read); } bdrv_dec_in_flight(bs); @@ -2561,6 +2563,7 @@ static void coroutine_fn bdrv_flush_co_entry(void *opaque) int coroutine_fn bdrv_co_flush(BlockDriverState *bs) { + BlockDriverState *storage_bs; int current_gen; int ret = 0; @@ -2590,7 +2593,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) } /* Write back cached data to the OS even with cache=unsafe */ - BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); + BLKDBG_EVENT(bdrv_storage_child(bs), BLKDBG_FLUSH_TO_OS); if (bs->drv->bdrv_co_flush_to_os) { ret = bs->drv->bdrv_co_flush_to_os(bs); if (ret < 0) { @@ -2608,7 +2611,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) goto flush_parent; } - BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); + BLKDBG_EVENT(bdrv_storage_child(bs), BLKDBG_FLUSH_TO_DISK); if (!bs->drv) { /* bs->drv->bdrv_co_flush() might have ejected the BDS * (even in case of apparent success) */ @@ -2653,7 +2656,8 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) * in the case of cache=unsafe, so there are no useless flushes. */ flush_parent: - ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0; + storage_bs = bdrv_storage_bs(bs); + ret = storage_bs ? bdrv_co_flush(storage_bs) : 0; out: /* Notify any pending flushes that we have completed */ if (ret == 0) { diff --git a/block/qapi.c b/block/qapi.c index f2eb83945e..cbee819c13 100644 --- a/block/qapi.c +++ b/block/qapi.c @@ -500,7 +500,7 @@ static void bdrv_query_blk_stats(BlockDeviceStats *ds, BlockBackend *blk) static BlockStats *bdrv_query_bds_stats(BlockDriverState *bs, bool blk_level) { - BlockDriverState *cow_bs; + BlockDriverState *storage_bs, *cow_bs; BlockStats *s = NULL; s = g_malloc0(sizeof(*s)); @@ -524,9 +524,10 @@ static BlockStats *bdrv_query_bds_stats(BlockDriverState *bs, s->stats->wr_highest_offset = stat64_get(&bs->wr_highest_offset); - if (bs->file) { + storage_bs = bdrv_storage_bs(bs); + if (storage_bs) { s->has_parent = true; - s->parent = bdrv_query_bds_stats(bs->file->bs, blk_level); + s->parent = bdrv_query_bds_stats(storage_bs, blk_level); } cow_bs = bdrv_filtered_cow_bs(bs); diff --git a/block/snapshot.c b/block/snapshot.c index f9903bc94e..2c5997fc73 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -154,8 +154,9 @@ int bdrv_can_snapshot(BlockDriverState *bs) } if (!drv->bdrv_snapshot_create) { - if (bs->file != NULL) { - return bdrv_can_snapshot(bs->file->bs); + BlockDriverState *storage_bs = bdrv_storage_bs(bs); + if (storage_bs) { + return bdrv_can_snapshot(storage_bs); } return 0; } @@ -167,14 +168,15 @@ int bdrv_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs = bdrv_storage_bs(bs); if (!drv) { return -ENOMEDIUM; } if (drv->bdrv_snapshot_create) { return drv->bdrv_snapshot_create(bs, sn_info); } - if (bs->file) { - return bdrv_snapshot_create(bs->file->bs, sn_info); + if (storage_bs) { + return bdrv_snapshot_create(storage_bs, sn_info); } return -ENOTSUP; } @@ -184,6 +186,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs; int ret, open_ret; if (!drv) { @@ -204,37 +207,38 @@ int bdrv_snapshot_goto(BlockDriverState *bs, return ret; } - if (bs->file) { - BlockDriverState *file; + storage_bs = bdrv_storage_bs(bs); + if (storage_bs) { QDict *options = qdict_clone_shallow(bs->options); QDict *file_options; Error *local_err = NULL; - file = bs->file->bs; /* Prevent it from getting deleted when detached from bs */ - bdrv_ref(file); + bdrv_ref(storage_bs); qdict_extract_subqdict(options, &file_options, "file."); qobject_unref(file_options); - qdict_put_str(options, "file", bdrv_get_node_name(file)); + qdict_put_str(options, "file", bdrv_get_node_name(storage_bs)); drv->bdrv_close(bs); + + assert(bs->file->bs == storage_bs); bdrv_unref_child(bs, bs->file); bs->file = NULL; - ret = bdrv_snapshot_goto(file, snapshot_id, errp); + ret = bdrv_snapshot_goto(storage_bs, snapshot_id, errp); open_ret = drv->bdrv_open(bs, options, bs->open_flags, &local_err); qobject_unref(options); if (open_ret < 0) { - bdrv_unref(file); + bdrv_unref(storage_bs); bs->drv = NULL; /* A bdrv_snapshot_goto() error takes precedence */ error_propagate(errp, local_err); return ret < 0 ? ret : open_ret; } - assert(bs->file->bs == file); - bdrv_unref(file); + assert(bs->file->bs == storage_bs); + bdrv_unref(storage_bs); return ret; } @@ -270,6 +274,7 @@ int bdrv_snapshot_delete(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs = bdrv_storage_bs(bs); int ret; if (!drv) { @@ -286,8 +291,8 @@ int bdrv_snapshot_delete(BlockDriverState *bs, if (drv->bdrv_snapshot_delete) { ret = drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp); - } else if (bs->file) { - ret = bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp); + } else if (storage_bs) { + ret = bdrv_snapshot_delete(storage_bs, snapshot_id, name, errp); } else { error_setg(errp, "Block format '%s' used by device '%s' " "does not support internal snapshot deletion", @@ -323,14 +328,15 @@ int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info) { BlockDriver *drv = bs->drv; + BlockDriverState *storage_bs = bdrv_storage_bs(bs); if (!drv) { return -ENOMEDIUM; } if (drv->bdrv_snapshot_list) { return drv->bdrv_snapshot_list(bs, psn_info); } - if (bs->file) { - return bdrv_snapshot_list(bs->file->bs, psn_info); + if (storage_bs) { + return bdrv_snapshot_list(storage_bs, psn_info); } return -ENOTSUP; } -- 2.17.1