Add fs subtype support to libfuse and fusermount

5 files changed, 127 insertions, 22 deletions

diff --git a/lib/fuse_versionscript b/lib/fuse_versionscript
index cbce074..6125f20 100644
--- a/lib/fuse_versionscript
+++ b/lib/fuse_versionscript
@@ -150,6 +150,7 @@ FUSE_2.7 {
 		fuse_fs_utimens;
 		fuse_fs_write;
 		fuse_register_module;
+		fuse_version;
 
 	local:
 		*;
diff --git a/lib/helper.c b/lib/helper.c
index 1de088f..d7cc9b7 100644
--- a/lib/helper.c
+++ b/lib/helper.c
@@ -29,7 +29,7 @@ enum  {
 struct helper_opts {
     int singlethread;
     int foreground;
-    int fsname;
+    int nodefault_subtype;
     char *mountpoint;
 };
 
@@ -40,7 +40,8 @@ static const struct fuse_opt fuse_helper_opts[] = {
     FUSE_HELPER_OPT("debug",       foreground),
     FUSE_HELPER_OPT("-f",          foreground),
     FUSE_HELPER_OPT("-s",          singlethread),
-    FUSE_HELPER_OPT("fsname=",     fsname),
+    FUSE_HELPER_OPT("fsname=",     nodefault_subtype),
+    FUSE_HELPER_OPT("subtype=",    nodefault_subtype),
 
     FUSE_OPT_KEY("-h",          KEY_HELP),
     FUSE_OPT_KEY("--help",      KEY_HELP),
@@ -50,6 +51,7 @@ static const struct fuse_opt fuse_helper_opts[] = {
     FUSE_OPT_KEY("-d",          FUSE_OPT_KEY_KEEP),
     FUSE_OPT_KEY("debug",       FUSE_OPT_KEY_KEEP),
     FUSE_OPT_KEY("fsname=",     FUSE_OPT_KEY_KEEP),
+    FUSE_OPT_KEY("subtype=",    FUSE_OPT_KEY_KEEP),
     FUSE_OPT_END
 };
 
@@ -117,24 +119,24 @@ static int fuse_helper_opt_proc(void *data, const char *arg, int key,
     }
 }
 
-static int add_default_fsname(const char *progname, struct fuse_args *args)
+static int add_default_subtype(const char *progname, struct fuse_args *args)
 {
     int res;
-    char *fsname_opt;
+    char *subtype_opt;
     const char *basename = strrchr(progname, '/');
     if (basename == NULL)
         basename = progname;
     else if (basename[1] != '\0')
         basename++;
 
-    fsname_opt = (char *) malloc(strlen(basename) + 64);
-    if (fsname_opt == NULL) {
+    subtype_opt = (char *) malloc(strlen(basename) + 64);
+    if (subtype_opt == NULL) {
         fprintf(stderr, "fuse: memory allocation failed\n");
         return -1;
     }
-    sprintf(fsname_opt, "-ofsname=%s", basename);
-    res = fuse_opt_add_arg(args, fsname_opt);
-    free(fsname_opt);
+    sprintf(subtype_opt, "-osubtype=%s", basename);
+    res = fuse_opt_add_arg(args, subtype_opt);
+    free(subtype_opt);
     return res;
 }
 
@@ -149,8 +151,8 @@ int fuse_parse_cmdline(struct fuse_args *args, char **mountpoint,
     if (res == -1)
         return -1;
 
-    if (!hopts.fsname) {
-        res = add_default_fsname(args->argv[0], args);
+    if (!hopts.nodefault_subtype) {
+        res = add_default_subtype(args->argv[0], args);
         if (res == -1)
             goto err;
     }
@@ -331,6 +333,11 @@ int fuse_main(void)
     return -1;
 }
 
+int fuse_version(void)
+{
+    return FUSE_VERSION;
+}
+
 #include "fuse_compat.h"
 
 #ifndef __FreeBSD__
diff --git a/lib/mount.c b/lib/mount.c
index 24bcf8c..aa0c0cb 100644
--- a/lib/mount.c
+++ b/lib/mount.c
@@ -39,6 +39,7 @@ enum {
     KEY_KERN_FLAG,
     KEY_KERN_OPT,
     KEY_FUSERMOUNT_OPT,
+    KEY_SUBTYPE_OPT,
     KEY_MTAB_OPT,
     KEY_ALLOW_ROOT,
     KEY_RO,
@@ -54,6 +55,8 @@ struct mount_opts {
     int nonempty;
     int blkdev;
     char *fsname;
+    char *subtype;
+    char *subtype_opt;
     char *mtab_opts;
     char *fusermount_opts;
     char *kernel_opts;
@@ -67,11 +70,13 @@ static const struct fuse_opt fuse_mount_opts[] = {
     FUSE_MOUNT_OPT("nonempty",          nonempty),
     FUSE_MOUNT_OPT("blkdev",            blkdev),
     FUSE_MOUNT_OPT("fsname=%s",         fsname),
+    FUSE_MOUNT_OPT("subtype=%s",        subtype),
     FUSE_OPT_KEY("allow_other",         KEY_KERN_OPT),
     FUSE_OPT_KEY("allow_root",          KEY_ALLOW_ROOT),
     FUSE_OPT_KEY("nonempty",            KEY_FUSERMOUNT_OPT),
     FUSE_OPT_KEY("blkdev",              KEY_FUSERMOUNT_OPT),
     FUSE_OPT_KEY("fsname=",             KEY_FUSERMOUNT_OPT),
+    FUSE_OPT_KEY("subtype=",            KEY_SUBTYPE_OPT),
     FUSE_OPT_KEY("large_read",          KEY_KERN_OPT),
     FUSE_OPT_KEY("blksize=",            KEY_KERN_OPT),
     FUSE_OPT_KEY("default_permissions", KEY_KERN_OPT),
@@ -107,6 +112,7 @@ static void mount_help(void)
             "    -o nonempty            allow mounts over non-empty file/dir\n"
             "    -o default_permissions enable permission checking by kernel\n"
             "    -o fsname=NAME         set filesystem name\n"
+            "    -o subtype=NAME        set filesystem type\n"
             "    -o large_read          issue large read requests (2.4 only)\n"
             "    -o max_read=N          set maximum size of read requests\n"
             "\n"
@@ -196,6 +202,9 @@ static int fuse_mount_opt_proc(void *data, const char *arg, int key,
     case KEY_FUSERMOUNT_OPT:
         return fuse_opt_add_opt(&mo->fusermount_opts, arg);
 
+    case KEY_SUBTYPE_OPT:
+        return fuse_opt_add_opt(&mo->subtype_opt, arg);
+
     case KEY_MTAB_OPT:
         return fuse_opt_add_opt(&mo->mtab_opts, arg);
 
@@ -304,7 +313,8 @@ void fuse_unmount_compat22(const char *mountpoint)
     fuse_kern_unmount(mountpoint, -1);
 }
 
-int fuse_mount_compat22(const char *mountpoint, const char *opts)
+static int fuse_mount_fusermount(const char *mountpoint, const char *opts,
+                                 int quiet)
 {
     int fds[2], pid;
     int res;
@@ -334,6 +344,12 @@ int fuse_mount_compat22(const char *mountpoint, const char *opts)
         const char *argv[32];
         int a = 0;
 
+        if (quiet) {
+            int fd = open("/dev/null", O_RDONLY);
+            dup2(fd, 1);
+            dup2(fd, 2);
+        }
+
         argv[a++] = FUSERMOUNT_PROG;
         if (opts) {
             argv[a++] = "-o";
@@ -360,13 +376,18 @@ int fuse_mount_compat22(const char *mountpoint, const char *opts)
     return rv;
 }
 
+int fuse_mount_compat22(const char *mountpoint, const char *opts)
+{
+    return fuse_mount_fusermount(mountpoint, opts, 0);
+}
 
 static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
                           const char *mnt_opts)
 {
-    const char *type = mo->blkdev ? "fuseblk" : "fuse";
     char tmp[128];
     const char *devname = "/dev/fuse";
+    char *source = NULL;
+    char *type = NULL;
     struct stat stbuf;
     int fd;
     int res;
@@ -395,9 +416,6 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
         return -1;
     }
 
-    if (mo->fsname)
-        devname = mo->fsname;
-
     snprintf(tmp, sizeof(tmp),  "fd=%i,rootmode=%o,user_id=%i,group_id=%i", fd,
              stbuf.st_mode & S_IFMT, getuid(), getgid());
 
@@ -405,16 +423,52 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
     if (res == -1)
         goto out_close;
 
-    res = mount(devname, mnt, type, mo->flags, mo->kernel_opts);
+    source = malloc((mo->fsname ? strlen(mo->fsname) : 0) +
+                    (mo->subtype ? strlen(mo->subtype) : 0) +
+                    strlen(devname) + 32);
+
+    type = malloc((mo->subtype ? strlen(mo->subtype) : 0) + 32);
+    if (!type || !source) {
+        fprintf(stderr, "fuse: failed to allocate memory\n");
+        goto out_close;
+    }
+
+    strcpy(type, mo->blkdev ? "fuseblk" : "fuse");
+    if (mo->subtype) {
+        strcat(type, ".");
+        strcat(type, mo->subtype);
+    }
+    strcpy(source,
+           mo->fsname ? mo->fsname : (mo->subtype ? mo->subtype : devname));
+
+    res = mount(source, mnt, type, mo->flags, mo->kernel_opts);
+    if (res == -1 && errno == ENODEV && mo->subtype) {
+        /* Probably missing subtype support */
+        strcpy(type, mo->blkdev ? "fuseblk" : "fuse");
+        if (mo->fsname) {
+            if (!mo->blkdev)
+                sprintf(source, "%s#%s", mo->subtype, mo->fsname);
+        } else {
+            strcpy(source, type);
+        }
+        res = mount(source, mnt, type, mo->flags, mo->kernel_opts);
+    }
     if (res == -1) {
         /*
          * Maybe kernel doesn't support unprivileged mounts, in this
          * case try falling back to fusermount
          */
-        if (errno == EPERM)
+        if (errno == EPERM) {
             res = -2;
-        else
-            perror("fuse: mount failed");
+        } else {
+            int errno_save = errno;
+            if (mo->blkdev && errno == ENODEV && !fuse_mnt_check_fuseblk())
+                fprintf(stderr, "fuse: 'fuseblk' support missing\n");
+            else
+                fprintf(stderr, "fuse: mount failed: %s\n",
+                        strerror(errno_save));
+        }
+
         goto out_close;
     }
 
@@ -424,7 +478,7 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
         if (!newmnt)
             goto out_umount;
 
-        res = fuse_mnt_add_mount("fuse", devname, newmnt, type, mnt_opts);
+        res = fuse_mnt_add_mount("fuse", source, newmnt, type, mnt_opts);
         free(newmnt);
         if (res == -1)
             goto out_umount;
@@ -435,6 +489,8 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
  out_umount:
     umount2(mnt, 2); /* lazy umount */
  out_close:
+    free(type);
+    free(source);
     close(fd);
     return res;
 }
@@ -460,6 +516,11 @@ int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
     int res = -1;
     char *mnt_opts = NULL;
 
+    if (!mountpoint) {
+        fprintf(stderr, "fuse: missing mountpoint\n");
+        return -1;
+    }
+
     memset(&mo, 0, sizeof(mo));
     mo.flags = MS_NOSUID | MS_NODEV;
 
@@ -489,12 +550,30 @@ int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
             fuse_opt_add_opt(&mnt_opts, mo.fusermount_opts) == -1)
             goto out;
 
-        res = fuse_mount_compat22(mountpoint, mnt_opts);
+        if (mo.subtype) {
+            char *tmp_opts = NULL;
+
+            res = -1;
+            if (fuse_opt_add_opt(&tmp_opts, mnt_opts) == -1 ||
+                fuse_opt_add_opt(&tmp_opts, mo.subtype_opt) == -1) {
+                free(tmp_opts);
+                goto out;
+            }
+
+            res = fuse_mount_fusermount(mountpoint, tmp_opts, 1);
+            free(tmp_opts);
+            if (res == -1)
+                res = fuse_mount_fusermount(mountpoint, mnt_opts, 0);
+        } else {
+            res = fuse_mount_fusermount(mountpoint, mnt_opts, 0);
+        }
     }
  out:
     free(mnt_opts);
     free(mo.fsname);
+    free(mo.subtype);
     free(mo.fusermount_opts);
+    free(mo.subtype_opt);
     free(mo.kernel_opts);
     free(mo.mtab_opts);
     return res;
diff --git a/lib/mount_util.c b/lib/mount_util.c
index 02b2731..dccecdf 100644
--- a/lib/mount_util.c
+++ b/lib/mount_util.c
@@ -193,3 +193,20 @@ int fuse_mnt_check_empty(const char *progname, const char *mnt,
     }
     return 0;
 }
+
+int fuse_mnt_check_fuseblk(void)
+{
+    char buf[256];
+    FILE *f = fopen("/proc/filesystems", "r");
+    if (!f)
+        return 1;
+
+    while (fgets(buf, sizeof(buf), f))
+        if (strstr(buf, "fuseblk\n")) {
+            fclose(f);
+            return 1;
+        }
+
+    fclose(f);
+    return 0;
+}
diff --git a/lib/mount_util.h b/lib/mount_util.h
index 106a6f8..f9f6cbe 100644
--- a/lib/mount_util.h
+++ b/lib/mount_util.h
@@ -14,3 +14,4 @@ int fuse_mnt_umount(const char *progname, const char *mnt, int lazy);
 char *fuse_mnt_resolve_path(const char *progname, const char *orig);
 int fuse_mnt_check_empty(const char *progname, const char *mnt,
                          mode_t rootmode, off_t rootsize);
+int fuse_mnt_check_fuseblk(void);