diff mbox series

[v2,3/4] block: detect DKIOCGETBLOCKCOUNT/SIZE before use

Message ID 20210309002741.85057-4-j@getutm.app
State New
Headers show
Series Disable unsupported features on iOS hosts | expand

Commit Message

Joelle van Dyne March 9, 2021, 12:27 a.m. UTC 
iOS hosts do not have these defined so we fallback to the
default behaviour.

Co-authored-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Joelle van Dyne <j@getutm.app>
---
 block/file-posix.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

Comments

Peter Maydell March 9, 2021, 11:31 a.m. UTC | #1 
On Tue, 9 Mar 2021 at 00:30, Joelle van Dyne <j@getutm.app> wrote:
>
> iOS hosts do not have these defined so we fallback to the
> default behaviour.
>
> Co-authored-by: Warner Losh <imp@bsdimp.com>
> Signed-off-by: Joelle van Dyne <j@getutm.app>
> ---
>  block/file-posix.c | 18 +++++++-----------
>  1 file changed, 7 insertions(+), 11 deletions(-)

raw_getlength() is a bit of a mess; this certainly seems like
an improvement...

> diff --git a/block/file-posix.c b/block/file-posix.c
> index d1ab3180ff..9b6d7ddda3 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -2326,8 +2326,10 @@ static int64_t raw_getlength(BlockDriverState *bs)
>  again:
>  #endif
>      if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
> +        size = 0;
>  #ifdef DIOCGMEDIASIZE
>          if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
> +            size = 0;

this if() should have braces {}.

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox series

Patch

diff --git a/block/file-posix.c b/block/file-posix.c
index d1ab3180ff..9b6d7ddda3 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2326,8 +2326,10 @@  static int64_t raw_getlength(BlockDriverState *bs)
 again:
 #endif
     if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
+        size = 0;
 #ifdef DIOCGMEDIASIZE
         if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
+            size = 0;
 #elif defined(DIOCGPART)
         {
                 struct partinfo pi;
@@ -2336,9 +2338,7 @@  again:
                 else
                         size = 0;
         }
-        if (size == 0)
-#endif
-#if defined(__APPLE__) && defined(__MACH__)
+#elif defined(DKIOCGETBLOCKCOUNT) && defined(DKIOCGETBLOCKSIZE)
         {
             uint64_t sectors = 0;
             uint32_t sector_size = 0;
@@ -2346,19 +2346,15 @@  again:
             if (ioctl(fd, DKIOCGETBLOCKCOUNT, &sectors) == 0
                && ioctl(fd, DKIOCGETBLOCKSIZE, &sector_size) == 0) {
                 size = sectors * sector_size;
-            } else {
-                size = lseek(fd, 0LL, SEEK_END);
-                if (size < 0) {
-                    return -errno;
-                }
             }
         }
-#else
-        size = lseek(fd, 0LL, SEEK_END);
+#endif
+        if (size == 0) {
+            size = lseek(fd, 0LL, SEEK_END);
+        }
         if (size < 0) {
             return -errno;
         }
-#endif
 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
         switch(s->type) {
         case FTYPE_CD: