On 01/02/2015 02:52 PM, Stefan Hajnoczi wrote:
On Thu, Dec 18, 2014 at 12:18:01PM +0100, Ekaterina Tumanova wrote:+#if defined(BLKSSZGET) +# define SECTOR_SIZE BLKSSZGET +#elif defined(DKIOCGETBLOCKSIZE) +# define SECTOR_SIZE DKIOCGETBLOCKSIZE +#elif defined(DIOCGSECTORSIZE) +# define SECTOR_SIZE DIOCGSECTORSIZE +#else + return -ENOTSUP +#endif + if (ioctl(fd, SECTOR_SIZE, sector_size) < 0) { + return -errno; + } + return 0; +#undef SECTOR_SIZENot a reason to respin, but I would have preferred simply moving the old code. I think the new code works because BLKSSZGET is Linux, DKIOCGETBLOCKSIZE is Mac OS, and DIOCGSECTORSIZE is FreeBSD. If there is a host OS where more than one ioctl is available and the first one fails then the new code is broken. The old code didn't use #elif so each ioctl had a chance to run.
In this case, why should it have a chance to run, if we only use one result at a time? (Old code overwrites first result with the second) Plus as far as I understand, in this hypothetical case of 2 ioctls defined, one will most probably will be a redefinition of another. p.s. ok to all further comments to patches. Thanks! Kate.
Also, the name SECTOR_SIZE is misleading. It's not a sector size value but the "get sector size" ioctl request code. Stefan
