[PATCH v2] erofs-utils: get block device size correctly

[gaoxiang25@huawei.com (Gao Xiang)]

On Thu, Aug 08, 2019@10:50:24AM +0800, shenmeng999 wrote:
> Hi hsiangkao:
>     I agree with your modification.It's getting better.Thanks!

OK, Let me update it to dev branch as well this evening :)

Thanks,
Gao Xiang

> 
> 
> At 2019-08-08 02:26:50, "Gao Xiang" <hsiangkao at aol.com>, said: 
> >Hi shenmeng,
> >
> >On Wed, Aug 07, 2019@10:36:55PM +0800, shenmeng999@126.com wrote:
> >> From: shenmeng996 <shenmeng999 at 126.com>
> >> 
> >> fstat return block device's size of zero.
> >> use ioctl to get block device's size.
> >> 
> >> Signed-off-by: shenmeng996 <shenmeng999 at 126.com>
> >
> >
> >Thanks for your patch v2 :)
> >
> >It looks good to me, and I update this patch so that
> >autoconf can check these new header files.
> >https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git/commit/?h=experimental&id=0f225449962b4a9716985e7530a395a9500d0de6
> >Do you agree with this modification? please share your thought about this.
> >
> >Thanks,
> >Gao Xiang
> >
> >diff --git a/configure.ac b/configure.ac
> >index 6f4eacc..fcdf30a 100644
> >--- a/configure.ac
> >+++ b/configure.ac
> >@@ -73,12 +73,14 @@ AC_CHECK_HEADERS(m4_flatten([
> > 	fcntl.h
> > 	inttypes.h
> > 	linux/falloc.h
> >+	linux/fs.h
> > 	linux/types.h
> > 	limits.h
> > 	stddef.h
> > 	stdint.h
> > 	stdlib.h
> > 	string.h
> >+	sys/ioctl.h
> > 	sys/stat.h
> > 	sys/time.h
> > 	unistd.h
> >diff --git a/lib/io.c b/lib/io.c
> >index 93328d3..15c5a35 100644
> >--- a/lib/io.c
> >+++ b/lib/io.c
> >@@ -9,7 +9,11 @@
> > #define _LARGEFILE64_SOURCE
> > #define _GNU_SOURCE
> > #include <sys/stat.h>
> >+#include <sys/ioctl.h>
> > #include "erofs/io.h"
> >+#ifdef HAVE_LINUX_FS_H
> >+#include <linux/fs.h>
> >+#endif
> > #ifdef HAVE_LINUX_FALLOC_H
> > #include <linux/falloc.h>
> > #endif
> >@@ -21,6 +25,26 @@ static const char *erofs_devname;
> > static int erofs_devfd = -1;
> > static u64 erofs_devsz;
> > 
> >+int dev_get_blkdev_size(int fd, u64 *bytes)
> >+{
> >+	errno = ENOTSUP;
> >+#ifdef BLKGETSIZE64
> >+	if (ioctl(fd, BLKGETSIZE64, bytes) >= 0)
> >+		return 0;
> >+#endif
> >+
> >+#ifdef BLKGETSIZE
> >+	{
> >+		unsigned long size;
> >+		if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
> >+			*bytes = ((u64)size << 9);
> >+			return 0;
> >+		}
> >+	}
> >+#endif
> >+	return -errno;
> >+}
> >+
> > void dev_close(void)
> > {
> > 	close(erofs_devfd);
> >@@ -49,7 +73,12 @@ int dev_open(const char *dev)
> > 
> > 	switch (st.st_mode & S_IFMT) {
> > 	case S_IFBLK:
> >-		erofs_devsz = st.st_size;
> >+		ret = dev_get_blkdev_size(fd, &erofs_devsz);
> >+		if (ret) {
> >+			erofs_err("failed to get block device size(%s).", dev);
> >+			close(fd);
> >+			return ret;
> >+		}
> > 		break;
> > 	case S_IFREG:
> > 		ret = ftruncate(fd, 0);
> >-- 
> >2.17.1