Re: [Qemu-devel] [PATCH v2 2/5] block: Avoid BlockDriverState.filename

[Wen Congyang <wency@cn.fujitsu.com>]

On 08/06/2015 04:52 AM, Max Reitz wrote:
> In places which directly pass a filename to the OS, we should not use
> the filename field at all but exact_filename instead (although the
> former currently equals the latter if that is set).
> 
> In qemu-img's map command, we should be using the filename field; but
> since this commit prepares to remove that field, using exact_filename is
> fine, too (this is the only user of BlockDriverState.filename which
> frequently queries that field).
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c           | 4 ++--
>  block/gluster.c   | 2 +-
>  block/raw-posix.c | 8 ++++----
>  block/raw-win32.c | 4 ++--
>  qemu-img.c        | 2 +-
>  5 files changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/block.c b/block.c
> index e7dd2f1..5a1dc16 100644
> --- a/block.c
> +++ b/block.c
> @@ -918,8 +918,8 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
>      if (ret < 0) {
>          if (local_err) {
>              error_propagate(errp, local_err);
> -        } else if (bs->filename[0]) {
> -            error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
> +        } else if (bs->exact_filename[0]) {
> +            error_setg_errno(errp, -ret, "Could not open '%s'", bs->exact_filename);
>          } else {
>              error_setg_errno(errp, -ret, "Could not open image");
>          }
> diff --git a/block/gluster.c b/block/gluster.c
> index 1eb3a8c..176682b 100644
> --- a/block/gluster.c
> +++ b/block/gluster.c
> @@ -358,7 +358,7 @@ static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
>  
>      gconf = g_new0(GlusterConf, 1);
>  
> -    reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename, errp);
> +    reop_s->glfs = qemu_gluster_init(gconf, state->bs->exact_filename, errp);
>      if (reop_s->glfs == NULL) {
>          ret = -errno;
>          goto exit;
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 855febe..b61c11f 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -671,7 +671,7 @@ static int raw_reopen_prepare(BDRVReopenState *state,
>      /* If we cannot use fcntl, or fcntl failed, fall back to qemu_open() */
>      if (raw_s->fd == -1) {
>          assert(!(raw_s->open_flags & O_CREAT));
> -        raw_s->fd = qemu_open(state->bs->filename, raw_s->open_flags);
> +        raw_s->fd = qemu_open(state->bs->exact_filename, raw_s->open_flags);

In raw_open_common(), we call raw_normalize_devicepath(). Why don't we call it
here?

Thanks
Wen Congyang

>          if (raw_s->fd == -1) {
>              error_setg_errno(errp, errno, "Could not reopen file");
>              ret = -1;
> @@ -2195,7 +2195,7 @@ static int fd_open(BlockDriverState *bs)
>              DPRINTF("No floppy (open delayed)\n");
>              return -EIO;
>          }
> -        s->fd = qemu_open(bs->filename, s->open_flags & ~O_NONBLOCK);
> +        s->fd = qemu_open(bs->exact_filename, s->open_flags & ~O_NONBLOCK);
>          if (s->fd < 0) {
>              s->fd_error_time = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
>              s->fd_got_error = 1;
> @@ -2486,7 +2486,7 @@ static void floppy_eject(BlockDriverState *bs, bool eject_flag)
>          qemu_close(s->fd);
>          s->fd = -1;
>      }
> -    fd = qemu_open(bs->filename, s->open_flags | O_NONBLOCK);
> +    fd = qemu_open(bs->exact_filename, s->open_flags | O_NONBLOCK);
>      if (fd >= 0) {
>          if (ioctl(fd, FDEJECT, 0) < 0)
>              perror("FDEJECT");
> @@ -2710,7 +2710,7 @@ static int cdrom_reopen(BlockDriverState *bs)
>       */
>      if (s->fd >= 0)
>          qemu_close(s->fd);
> -    fd = qemu_open(bs->filename, s->open_flags, 0644);
> +    fd = qemu_open(bs->exact_filename, s->open_flags, 0644);
>      if (fd < 0) {
>          s->fd = -1;
>          return -EIO;
> diff --git a/block/raw-win32.c b/block/raw-win32.c
> index 68f2338..5c8a894 100644
> --- a/block/raw-win32.c
> +++ b/block/raw-win32.c
> @@ -417,7 +417,7 @@ static void raw_close(BlockDriverState *bs)
>  
>      CloseHandle(s->hfile);
>      if (bs->open_flags & BDRV_O_TEMPORARY) {
> -        unlink(bs->filename);
> +        unlink(bs->exact_filename);
>      }
>  }
>  
> @@ -485,7 +485,7 @@ static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
>                                                DWORD * high);
>      get_compressed_t get_compressed;
>      struct _stati64 st;
> -    const char *filename = bs->filename;
> +    const char *filename = bs->exact_filename;
>      /* WinNT support GetCompressedFileSize to determine allocate size */
>      get_compressed =
>          (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
> diff --git a/qemu-img.c b/qemu-img.c
> index 75f4ee4..3d5587a 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -2155,7 +2155,7 @@ static void dump_map_entry(OutputFormat output_format, MapEntry *e,
>          }
>          if ((e->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) == BDRV_BLOCK_DATA) {
>              printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n",
> -                   e->start, e->length, e->offset, e->bs->filename);
> +                   e->start, e->length, e->offset, e->bs->exact_filename);
>          }
>          /* This format ignores the distinction between 0, ZERO and ZERO|DATA.
>           * Modify the flags here to allow more coalescing.
>