/* do this by looking for the longest mount point which matches the
current directory */
int
guess_disk (
char * cwd,
size_t cwd_len,
char ** dn_guess,
char ** mpt_guess)
{
size_t longest_match = 0;
size_t current_length;
size_t cwd_length;
int local_disk = 0;
generic_fsent_t fsent;
char *fsname = NULL;
char *disk_try = NULL;
*dn_guess = NULL;
*mpt_guess = NULL;
if (getcwd(cwd, cwd_len) == NULL) {
return -1;
/*NOTREACHED*/
}
cwd_length = strlen(cwd);
dbprintf(_("guess_disk: %zu: \"%s\"\n"), cwd_length, cwd);
if (open_fstab() == 0) {
return -1;
/*NOTREACHED*/
}
while (get_fstab_nextentry(&fsent))
{
current_length = fsent.mntdir ? strlen(fsent.mntdir) : (size_t)0;
dbprintf(_("guess_disk: %zu: %zu: \"%s\": \"%s\"\n"),
longest_match,
current_length,
fsent.mntdir ? fsent.mntdir : _("(mntdir null)"),
fsent.fsname ? fsent.fsname : _("(fsname null)"));
if ((current_length > longest_match)
&& (current_length <= cwd_length)
&& (g_str_has_prefix(cwd, fsent.mntdir)))
{
longest_match = current_length;
g_free(*mpt_guess);
*mpt_guess = g_strdup(fsent.mntdir);
if(strncmp(fsent.fsname,DEV_PREFIX,(strlen(DEV_PREFIX))))
{
g_free(fsname);
fsname = g_strdup(fsent.fsname);
}
else
{
g_free(fsname);
fsname = g_strdup(fsent.fsname + strlen(DEV_PREFIX));
}
local_disk = is_local_fstype(&fsent);
dbprintf(_("guess_disk: local_disk = %d, fsname = \"%s\"\n"),
local_disk,
fsname);
}
}
close_fstab();
if (longest_match == 0) {
amfree(*mpt_guess);
amfree(fsname);
return -1; /* ? at least / should match */
}
if (!local_disk) {
amfree(*mpt_guess);
amfree(fsname);
return 0;
}
/* have mount point now */
/* disk name may be specified by mount point (logical name) or
device name, have to determine */
g_printf(_("Trying disk %s ...\n"), *mpt_guess);
disk_try = g_strconcat("DISK ", *mpt_guess, NULL); /* try logical name */
if (exchange(disk_try) == -1)
exit(1);
amfree(disk_try);
if (server_happy())
{
*dn_guess = g_strdup(*mpt_guess); /* logical is okay */
amfree(fsname);
return 1;
}
g_printf(_("Trying disk %s ...\n"), fsname);
disk_try = g_strconcat("DISK ", fsname, NULL); /* try device name */
if (exchange(disk_try) == -1)
exit(1);
amfree(disk_try);
if (server_happy())
{
*dn_guess = g_strdup(fsname); /* dev name is okay */
amfree(fsname);
return 1;
}
/* neither is okay */
amfree(*mpt_guess);
amfree(fsname);
return 2;
}
int boot_info_open_partition(const char *name, uint64_t *out_size, int flags)
{
char *path;
int fd;
struct fstab *fstab;
struct fstab_rec *record;
// We can't use fs_mgr to look up |name| because fstab doesn't list
// every slot partition (it uses the slotselect option to mask the
// suffix) and |slot| is expected to be of that form, e.g. boot_a.
//
// We can however assume that there's an entry for the /misc mount
// point and use that to get the device file for the misc
// partition. From there we'll assume that a by-name scheme is used
// so we can just replace the trailing "misc" by the given |name|,
// e.g.
//
// /dev/block/platform/soc.0/7824900.sdhci/by-name/misc ->
// /dev/block/platform/soc.0/7824900.sdhci/by-name/boot_a
//
// If needed, it's possible to relax this assumption in the future
// by trawling /sys/block looking for the appropriate sibling of
// misc and then finding an entry in /dev matching the sysfs entry.
fstab = open_fstab();
if (fstab == NULL)
return -1;
record = fs_mgr_get_entry_for_mount_point(fstab, "/misc");
if (record == NULL) {
fs_mgr_free_fstab(fstab);
return -1;
}
if (strcmp(name, "misc") == 0) {
path = strdup(record->blk_device);
} else {
size_t trimmed_len, name_len;
const char *end_slash = strrchr(record->blk_device, '/');
if (end_slash == NULL) {
fs_mgr_free_fstab(fstab);
return -1;
}
trimmed_len = end_slash - record->blk_device + 1;
name_len = strlen(name);
path = calloc(trimmed_len + name_len + 1, 1);
strncpy(path, record->blk_device, trimmed_len);
strncpy(path + trimmed_len, name, name_len);
}
fs_mgr_free_fstab(fstab);
fd = open(path, flags);
free(path);
// If we successfully opened the device, get size if requested.
if (fd != -1 && out_size != NULL) {
if (ioctl(fd, BLKGETSIZE64, out_size) != 0) {
close(fd);
return -1;
}
}
return fd;
}
