| Message ID | 1402917843-6459-21-git-send-email-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 16 June 2014 12:23, Stefan Hajnoczi <stefanha@redhat.com> wrote: > From: Chunyan Liu <cyliu@suse.com> > > Reviewed-by: Eric Blake <eblake@redhat.com> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> > Signed-off-by: Chunyan Liu <cyliu@suse.com> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > block/cow.c | 54 ++++++++++++++++++++++++++---------------------------- > 1 file changed, 26 insertions(+), 28 deletions(-) > > diff --git a/block/cow.c b/block/cow.c > index 7e61024..af85753 100644 > --- a/block/cow.c > +++ b/block/cow.c > @@ -324,31 +324,24 @@ static void cow_close(BlockDriverState *bs) > { > } > > -static int cow_create(const char *filename, QEMUOptionParameter *options, > - Error **errp) > +static int cow_create(const char *filename, QemuOpts *opts, Error **errp) > { > struct cow_header_v2 cow_header; > struct stat st; > int64_t image_sectors = 0; > - const char *image_filename = NULL; > + char *image_filename = NULL; > Error *local_err = NULL; > int ret; > BlockDriverState *cow_bs; > > /* Read out options */ > - while (options && options->name) { > - if (!strcmp(options->name, BLOCK_OPT_SIZE)) { > - image_sectors = options->value.n / 512; > - } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { > - image_filename = options->value.s; > - } > - options++; > - } > + image_sectors = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0) / 512; > + image_filename = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); > > - ret = bdrv_create_file(filename, options, NULL, &local_err); > + ret = bdrv_create_file(filename, NULL, opts, &local_err); > if (ret < 0) { > error_propagate(errp, local_err); > - return ret; > + goto exit; > } > > cow_bs = NULL; This change means we now have a 'goto exit' before cow_bs is initialized, and the exit: code path uses cow_bs: > > exit: > + g_free(image_filename); > bdrv_unref(cow_bs); > return ret; > } clang 3.4 correctly warns: /home/petmay01/linaro/qemu-from-laptop/qemu/block/cow.c:342:9: warning: variable 'cow_bs' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (ret < 0) { ^~~~~~~ /home/petmay01/linaro/qemu-from-laptop/qemu/block/cow.c:386:16: note: uninitialized use occurs here bdrv_unref(cow_bs); ^~~~~~ /home/petmay01/linaro/qemu-from-laptop/qemu/block/cow.c:342:5: note: remove the 'if' if its condition is always false if (ret < 0) { ^~~~~~~~~~~~~~ /home/petmay01/linaro/qemu-from-laptop/qemu/block/cow.c:335:29: note: initialize the variable 'cow_bs' to silence this warning BlockDriverState *cow_bs; ^ = NULL 1 warning generated. Patch to follow. thanks -- PMM
diff --git a/block/cow.c b/block/cow.c index 7e61024..af85753 100644 --- a/block/cow.c +++ b/block/cow.c @@ -324,31 +324,24 @@ static void cow_close(BlockDriverState *bs) { } -static int cow_create(const char *filename, QEMUOptionParameter *options, - Error **errp) +static int cow_create(const char *filename, QemuOpts *opts, Error **errp) { struct cow_header_v2 cow_header; struct stat st; int64_t image_sectors = 0; - const char *image_filename = NULL; + char *image_filename = NULL; Error *local_err = NULL; int ret; BlockDriverState *cow_bs; /* Read out options */ - while (options && options->name) { - if (!strcmp(options->name, BLOCK_OPT_SIZE)) { - image_sectors = options->value.n / 512; - } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { - image_filename = options->value.s; - } - options++; - } + image_sectors = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0) / 512; + image_filename = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); - ret = bdrv_create_file(filename, options, NULL, &local_err); + ret = bdrv_create_file(filename, NULL, opts, &local_err); if (ret < 0) { error_propagate(errp, local_err); - return ret; + goto exit; } cow_bs = NULL; @@ -356,7 +349,7 @@ static int cow_create(const char *filename, QEMUOptionParameter *options, BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err); if (ret < 0) { error_propagate(errp, local_err); - return ret; + goto exit; } memset(&cow_header, 0, sizeof(cow_header)); @@ -389,22 +382,27 @@ static int cow_create(const char *filename, QEMUOptionParameter *options, } exit: + g_free(image_filename); bdrv_unref(cow_bs); return ret; } -static QEMUOptionParameter cow_create_options[] = { - { - .name = BLOCK_OPT_SIZE, - .type = OPT_SIZE, - .help = "Virtual disk size" - }, - { - .name = BLOCK_OPT_BACKING_FILE, - .type = OPT_STRING, - .help = "File name of a base image" - }, - { NULL } +static QemuOptsList cow_create_opts = { + .name = "cow-create-opts", + .head = QTAILQ_HEAD_INITIALIZER(cow_create_opts.head), + .desc = { + { + .name = BLOCK_OPT_SIZE, + .type = QEMU_OPT_SIZE, + .help = "Virtual disk size" + }, + { + .name = BLOCK_OPT_BACKING_FILE, + .type = QEMU_OPT_STRING, + .help = "File name of a base image" + }, + { /* end of list */ } + } }; static BlockDriver bdrv_cow = { @@ -414,14 +412,14 @@ static BlockDriver bdrv_cow = { .bdrv_probe = cow_probe, .bdrv_open = cow_open, .bdrv_close = cow_close, - .bdrv_create = cow_create, + .bdrv_create2 = cow_create, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_read = cow_co_read, .bdrv_write = cow_co_write, .bdrv_co_get_block_status = cow_co_get_block_status, - .create_options = cow_create_options, + .create_opts = &cow_create_opts, }; static void bdrv_cow_init(void)