diff options
author | Richard W.M. Jones <rjones@redhat.com> | 2012-06-13 17:27:56 +0100 |
---|---|---|
committer | Richard W.M. Jones <rjones@redhat.com> | 2012-06-13 22:10:36 +0100 |
commit | c0a087b8236755e95371d5c352c9d29a3ca992c0 (patch) | |
tree | d85c99f1f43fbd29c257ea57037509f742579ef4 /daemon/guestfsd.c | |
parent | 4165e28b53d7024c38a171586acfb5c5b2c858b7 (diff) | |
download | libguestfs-c0a087b8236755e95371d5c352c9d29a3ca992c0.tar.gz libguestfs-c0a087b8236755e95371d5c352c9d29a3ca992c0.tar.xz libguestfs-c0a087b8236755e95371d5c352c9d29a3ca992c0.zip |
daemon: Fix order of devices in guestfs_list_devices when > 26 disks.
Sort the device names correctly, not just treating them as
strings. As a result, /dev/sdz < /dev/sdaa.
Diffstat (limited to 'daemon/guestfsd.c')
-rw-r--r-- | daemon/guestfsd.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index a7c111b0..b09f74e1 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -40,6 +40,7 @@ #include <arpa/inet.h> #include <netinet/in.h> #include <errno.h> +#include <assert.h> #ifdef HAVE_PRINTF_H # include <printf.h> @@ -514,6 +515,69 @@ free_stringslen (char **argv, size_t len) free (argv); } +/* Compare device names (including partition numbers if present). + * https://rwmj.wordpress.com/2011/01/09/how-are-linux-drives-named-beyond-drive-26-devsdz/ + */ +int +compare_device_names (const char *a, const char *b) +{ + size_t a_devlen, b_devlen; + int r; + int a_partnum, b_partnum; + + /* Skip /dev/ prefix if present. */ + if (STRPREFIX (a, "/dev/")) + a += 5; + if (STRPREFIX (b, "/dev/")) + b += 5; + + /* Skip sd/hd/vd. */ + assert (a[1] == 'd'); + a += 2; + assert (b[1] == 'd'); + b += 2; + + /* Get device name part, that is, just 'a', 'ab' etc. */ + a_devlen = strcspn (a, "0123456789"); + b_devlen = strcspn (b, "0123456789"); + + /* If device name part is longer, it is always greater, eg. + * "/dev/sdz" < "/dev/sdaa". + */ + if (a_devlen != b_devlen) + return a_devlen - b_devlen; + + /* Device name parts are the same length, so do a regular compare. */ + r = strncmp (a, b, a_devlen); + if (r != 0) + return r; + + /* Compare partitions numbers. */ + a += a_devlen; + b += a_devlen; + + r = sscanf (a, "%d", &a_partnum); + assert (r == 1); + r = sscanf (b, "%d", &b_partnum); + assert (r == 1); + + return a_partnum - b_partnum; +} + +static int +compare_device_names_vp (const void *vp1, const void *vp2) +{ + char * const *p1 = (char * const *) vp1; + char * const *p2 = (char * const *) vp2; + return compare_device_names (*p1, *p2); +} + +void +sort_device_names (char **argv, size_t len) +{ + qsort (argv, len, sizeof (char *), compare_device_names_vp); +} + /* Easy ways to run external commands. For full documentation, see * 'commandrvf' below. */ |