Reduce the size of mount (and bypass /proc/filesystems) by using the sysfs

system call, based on work done by Glenn McGrath in December.
 -Erik


git-svn-id: svn://busybox.net/trunk/busybox@1947 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 14 insertions, 61 deletions

diff --git a/util-linux/mount.c b/util-linux/mount.c
index 76cab7d79..2353a8ac2 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -83,6 +83,7 @@ extern int mount (__const char *__special_file, __const char *__dir,
                         __const void *__data);
 extern int umount (__const char *__special_file);
 extern int umount2 (__const char *__special_file, int __flags);
+static _syscall3(int, sysfs, int, option, unsigned int, fs_index, char *, buf);
 
 
 extern const char mtab_file[];  /* Defined in utility.c */
@@ -233,72 +234,24 @@ mount_one(char *blockDevice, char *directory, char *filesystemType,
 {
         int status = 0;
 
-        char buf[255];
         if (strcmp(filesystemType, "auto") == 0) {
-                FILE *f = xfopen("/proc/filesystems", "r");
-
-                while (fgets(buf, sizeof(buf), f) != NULL) {
-                        filesystemType = buf;
-                        if (*filesystemType == '\t') {  // Not a nodev filesystem
-
-                                // Add NULL termination to each line
-                                while (*filesystemType && *filesystemType != '\n')
-                                        filesystemType++;
-                                *filesystemType = '\0';
-
-                                filesystemType = buf;
-                                filesystemType++;       // hop past tab
-
-                                status = do_mount(blockDevice, directory, filesystemType,
-                                                                  flags | MS_MGC_VAL, string_flags,
-                                                                  useMtab, fakeIt, mtab_opts);
-                                if (status == TRUE)
-                                        break;
-                        }
-                }
-                fclose(f);
-        } else
-#if defined BB_FEATURE_USE_DEVPS_PATCH
-        if (strcmp(filesystemType, "auto") == 0) {
-                int fd, i, numfilesystems;
-                char device[] = "/dev/mtab";
-                struct k_fstype *fslist;
-
-                /* open device */ 
-                fd = open(device, O_RDONLY);
-                if (fd < 0)
-                        perror_msg_and_die("open failed for `%s'", device);
-
-                /* How many filesystems?  We need to know to allocate enough space */
-                numfilesystems = ioctl (fd, DEVMTAB_COUNT_FILESYSTEMS);
-                if (numfilesystems<0)
-                        perror_msg_and_die("\nDEVMTAB_COUNT_FILESYSTEMS");
-                fslist = (struct k_fstype *) xcalloc ( numfilesystems, sizeof(struct k_fstype));
-
-                /* Grab the list of available filesystems */
-                status = ioctl (fd, DEVMTAB_GET_FILESYSTEMS, fslist);
-                if (status<0)
-                        perror_msg_and_die("\nDEVMTAB_GET_FILESYSTEMS");
-
-                /* Walk the list trying to mount filesystems 
-                 * that do not claim to be nodev filesystems */
-                for( i = 0 ; i < numfilesystems ; i++) {
-                        if (fslist[i].mnt_nodev)
-                                continue;
-                        status = do_mount(blockDevice, directory, fslist[i].mnt_type,
-                                                          flags | MS_MGC_VAL, string_flags,
-                                                          useMtab, fakeIt, mtab_opts);
+                int i=0;
+                const int num_of_filesystems = sysfs(3, 0, 0);
+                char buf[255];
+                filesystemType=buf;
+
+                while(i < num_of_filesystems) {
+                        sysfs(2, i++, filesystemType);
+                        status = do_mount(blockDevice, directory, filesystemType,
+                                        flags | MS_MGC_VAL, string_flags,
+                                        useMtab, fakeIt, mtab_opts);
                         if (status == TRUE)
                                 break;
                 }
-                free( fslist);
-                close(fd);
-        } else
-#endif
-        {
+        } else {
                 status = do_mount(blockDevice, directory, filesystemType,
-                                                  flags | MS_MGC_VAL, string_flags, useMtab,
-                                                  fakeIt, mtab_opts);
+                                flags | MS_MGC_VAL, string_flags, useMtab,
+                                fakeIt, mtab_opts);
         }
 
         if (status == FALSE) {