| Message ID | 1386954633-28905-12-git-send-email-mreitz@redhat.com |
|---|---|
| State | New |
| Headers | show |
Am 13.12.2013 um 18:10 hat Max Reitz geschrieben: > blkdebug and blkverify will, in order to retain compatibility, not > support the field "file" implicitly through bdrv_open(). In order to be > able to use those drivers without giving a filename anyway, it is > necessary to be able to have block devices without files implicitly > opened by bdrv_open(). This is the case, if there was neither a file > name, a reference to an existing block device to use as a file nor > options specific to the file. > > Signed-off-by: Max Reitz <mreitz@redhat.com> > --- > block.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/block.c b/block.c > index bef4f82..9659eb5 100644 > --- a/block.c > +++ b/block.c > @@ -1145,11 +1145,14 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, > qdict_extract_subqdict(options, &file_options, "file."); > file_reference = qdict_get_try_str(options, "file"); > > - ret = bdrv_file_open(&file, filename, file_reference, file_options, > - bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err); > - qdict_del(options, "file"); > - if (ret < 0) { > - goto fail; > + if (filename || file_reference || qdict_size(file_options)) { > + ret = bdrv_file_open(&file, filename, file_reference, file_options, > + bdrv_open_flags(bs, flags | BDRV_O_UNMAP), > + &local_err); > + qdict_del(options, "file"); > + if (ret < 0) { > + goto fail; > + } > } > > /* Find the right image format driver */ > @@ -1178,7 +1181,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, Manually adding more context before the next hunk: > if (!drv) { > ret = find_image_format(file, filename, &drv, &local_err); > } We can get file == NULL now, which will cause a segfault in find_image_format. (For a reproducer of the segfault, try 'x86_64-softmmu/qemu-system-x86_64 -drive foo=bar') Kevin
On 13.12.2013 21:06, Kevin Wolf wrote: > Am 13.12.2013 um 18:10 hat Max Reitz geschrieben: >> blkdebug and blkverify will, in order to retain compatibility, not >> support the field "file" implicitly through bdrv_open(). In order to be >> able to use those drivers without giving a filename anyway, it is >> necessary to be able to have block devices without files implicitly >> opened by bdrv_open(). This is the case, if there was neither a file >> name, a reference to an existing block device to use as a file nor >> options specific to the file. >> >> Signed-off-by: Max Reitz <mreitz@redhat.com> >> --- >> block.c | 15 +++++++++------ >> 1 file changed, 9 insertions(+), 6 deletions(-) >> >> diff --git a/block.c b/block.c >> index bef4f82..9659eb5 100644 >> --- a/block.c >> +++ b/block.c >> @@ -1145,11 +1145,14 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, >> qdict_extract_subqdict(options, &file_options, "file."); >> file_reference = qdict_get_try_str(options, "file"); >> >> - ret = bdrv_file_open(&file, filename, file_reference, file_options, >> - bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err); >> - qdict_del(options, "file"); >> - if (ret < 0) { >> - goto fail; >> + if (filename || file_reference || qdict_size(file_options)) { >> + ret = bdrv_file_open(&file, filename, file_reference, file_options, >> + bdrv_open_flags(bs, flags | BDRV_O_UNMAP), >> + &local_err); >> + qdict_del(options, "file"); >> + if (ret < 0) { >> + goto fail; >> + } >> } >> >> /* Find the right image format driver */ >> @@ -1178,7 +1181,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, > Manually adding more context before the next hunk: > >> if (!drv) { >> ret = find_image_format(file, filename, &drv, &local_err); >> } > We can get file == NULL now, which will cause a segfault in > find_image_format. (For a reproducer of the segfault, try > 'x86_64-softmmu/qemu-system-x86_64 -drive foo=bar') Right, thanks. Max
diff --git a/block.c b/block.c index bef4f82..9659eb5 100644 --- a/block.c +++ b/block.c @@ -1145,11 +1145,14 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, qdict_extract_subqdict(options, &file_options, "file."); file_reference = qdict_get_try_str(options, "file"); - ret = bdrv_file_open(&file, filename, file_reference, file_options, - bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err); - qdict_del(options, "file"); - if (ret < 0) { - goto fail; + if (filename || file_reference || qdict_size(file_options)) { + ret = bdrv_file_open(&file, filename, file_reference, file_options, + bdrv_open_flags(bs, flags | BDRV_O_UNMAP), + &local_err); + qdict_del(options, "file"); + if (ret < 0) { + goto fail; + } } /* Find the right image format driver */ @@ -1178,7 +1181,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, goto unlink_and_fail; } - if (bs->file != file) { + if (file && (bs->file != file)) { bdrv_unref(file); file = NULL; }
blkdebug and blkverify will, in order to retain compatibility, not support the field "file" implicitly through bdrv_open(). In order to be able to use those drivers without giving a filename anyway, it is necessary to be able to have block devices without files implicitly opened by bdrv_open(). This is the case, if there was neither a file name, a reference to an existing block device to use as a file nor options specific to the file. Signed-off-by: Max Reitz <mreitz@redhat.com> --- block.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)