From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57785) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYKTw-0004eB-Kt for qemu-devel@nongnu.org; Wed, 27 Jun 2018 20:08:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYKTv-000472-95 for qemu-devel@nongnu.org; Wed, 27 Jun 2018 20:08:16 -0400 From: Max Reitz Date: Thu, 28 Jun 2018 02:07:25 +0200 Message-Id: <20180628000745.4477-12-mreitz@redhat.com> In-Reply-To: <20180628000745.4477-1-mreitz@redhat.com> References: <20180628000745.4477-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v9 11/31] block: bdrv_get_full_backing_filename's ret. val. 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 Make bdrv_get_full_backing_filename() return an allocated string instead of placing the result in a caller-provided buffer. Signed-off-by: Max Reitz --- include/block/block.h | 3 +-- block.c | 48 +++++++++++++++---------------------------- block/qapi.c | 12 ++--------- 3 files changed, 20 insertions(+), 43 deletions(-) diff --git a/include/block/block.h b/include/block/block.h index 5f9c32b0f6..7c4ff51f8a 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -457,8 +457,7 @@ void bdrv_round_to_clusters(BlockDriverState *bs, void bdrv_get_backing_filename(BlockDriverState *bs, char *filename, int filename_size); -void bdrv_get_full_backing_filename(BlockDriverState *bs, - char *dest, size_t sz, Error **errp); +char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); char *bdrv_get_full_backing_filename_from_filename(const char *backed, const char *backing, Error **errp); diff --git a/block.c b/block.c index fbec6680c8..400cc0d071 100644 --- a/block.c +++ b/block.c @@ -319,28 +319,16 @@ char *bdrv_get_full_backing_filename_from_filename(const char *backed, } } -void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, - Error **errp) +char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) { char *backed; - char *full_name; - Error *local_error = NULL; bdrv_refresh_filename(bs); backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; - - full_name = bdrv_get_full_backing_filename_from_filename(backed, - bs->backing_file, - &local_error); - if (full_name) { - pstrcpy(dest, sz, full_name); - g_free(full_name); - } else if (local_error) { - error_propagate(errp, local_error); - } else if (sz > 0) { - *dest = '\0'; - } + return bdrv_get_full_backing_filename_from_filename(backed, + bs->backing_file, + errp); } void bdrv_register(BlockDriver *bdrv) @@ -2305,7 +2293,7 @@ out: int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *bdref_key, Error **errp) { - char *backing_filename = g_malloc0(PATH_MAX); + char *backing_filename = NULL; char *bdref_key_dot; const char *reference = NULL; int ret = 0; @@ -2340,7 +2328,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, */ reference = qdict_get_try_str(parent_options, bdref_key); if (reference || qdict_haskey(options, "file.filename")) { - backing_filename[0] = '\0'; + /* keep backing_filename NULL */ } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { qobject_unref(options); goto free_exit; @@ -2355,8 +2343,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file); } - bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, - &local_err); + backing_filename = bdrv_get_full_backing_filename(bs, &local_err); if (local_err) { ret = -EINVAL; error_propagate(errp, local_err); @@ -2377,9 +2364,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qdict_put_str(options, "driver", bs->backing_format); } - backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, - reference, options, 0, bs, &child_backing, - errp); + backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs, + &child_backing, errp); if (!backing_hd) { bs->open_flags |= BDRV_O_NO_BACKING; error_prepend(errp, "Could not open backing file: "); @@ -4295,7 +4281,6 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, int is_protocol = 0; BlockDriverState *curr_bs = NULL; BlockDriverState *retval = NULL; - Error *local_error = NULL; if (!bs || !bs->drv || !backing_file) { return NULL; @@ -4315,21 +4300,22 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, /* If either of the filename paths is actually a protocol, then * compare unmodified paths; otherwise make paths relative */ if (is_protocol || path_has_protocol(curr_bs->backing_file)) { + char *backing_file_full_ret; + if (strcmp(backing_file, curr_bs->backing_file) == 0) { retval = curr_bs->backing->bs; break; } /* Also check against the full backing filename for the image */ - bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX, - &local_error); - if (local_error == NULL) { - if (strcmp(backing_file, backing_file_full) == 0) { + backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs, + NULL); + if (backing_file_full_ret) { + bool equal = strcmp(backing_file, backing_file_full_ret) == 0; + g_free(backing_file_full_ret); + if (equal) { retval = curr_bs->backing->bs; break; } - } else { - error_free(local_error); - local_error = NULL; } } else { /* If not an absolute filename path, make it relative to the current diff --git a/block/qapi.c b/block/qapi.c index 1c59febfef..b573a60609 100644 --- a/block/qapi.c +++ b/block/qapi.c @@ -291,18 +291,10 @@ void bdrv_query_image_info(BlockDriverState *bs, backing_filename = bs->backing_file; if (backing_filename[0] != '\0') { - char *backing_filename2 = g_malloc0(PATH_MAX); + char *backing_filename2; info->backing_filename = g_strdup(backing_filename); info->has_backing_filename = true; - bdrv_get_full_backing_filename(bs, backing_filename2, PATH_MAX, &err); - if (err) { - /* Can't reconstruct the full backing filename, so we must omit - * this field and apply a Best Effort to this query. */ - g_free(backing_filename2); - backing_filename2 = NULL; - error_free(err); - err = NULL; - } + backing_filename2 = bdrv_get_full_backing_filename(bs, NULL); /* Always report the full_backing_filename if present, even if it's the * same as backing_filename. That they are same is useful info. */ -- 2.17.1