Imported Upstream version 1.2.1

[sven/exfat-utils.git] / libexfat / mount.c

diff --git a/libexfat/mount.c b/libexfat/mount.c
index 2ebf43625315701e99eba3a543250420a44ce60c..f1fb01a9a88c8ee20eb3730c6669ee905cfbfcd3 100644 (file)
--- a/libexfat/mount.c
+++ b/libexfat/mount.c
@@ -3,7 +3,7 @@
        exFAT file system implementation library.
 
        Free exFAT implementation.
-       Copyright (C) 2010-2014  Andrew Nayenko
+       Copyright (C) 2010-2015  Andrew Nayenko
 
        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
@@ -30,23 +30,32 @@
 
 static uint64_t rootdir_size(const struct exfat* ef)
 {
-       uint64_t clusters = 0;
+       uint32_t clusters = 0;
+       uint32_t clusters_max = le32_to_cpu(ef->sb->cluster_count);
        cluster_t rootdir_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
 
-       while (!CLUSTER_INVALID(rootdir_cluster))
+       /* Iterate all clusters of the root directory to calculate its size.
+          It can't be contiguous because there is no flag to indicate this. */
+       do
        {
-               clusters++;
-               /* root directory cannot be contiguous because there is no flag
-                  to indicate this */
+               if (clusters == clusters_max) /* infinite loop detected */
+               {
+                       exfat_error("root directory cannot occupy all %d clusters",
+                                       clusters);
+                       return 0;
+               }
+               if (CLUSTER_INVALID(rootdir_cluster))
+               {
+                       exfat_error("bad cluster %#x while reading root directory",
+                                       rootdir_cluster);
+                       return 0;
+               }
                rootdir_cluster = exfat_next_cluster(ef, ef->root, rootdir_cluster);
+               clusters++;
        }
-       if (rootdir_cluster != EXFAT_CLUSTER_END)
-       {
-               exfat_error("bad cluster %#x while reading root directory",
-                               rootdir_cluster);
-               return 0;
-       }
-       return clusters * CLUSTER_SIZE(*ef->sb);
+       while (rootdir_cluster != EXFAT_CLUSTER_END);
+
+       return (uint64_t) clusters * CLUSTER_SIZE(*ef->sb);
 }
 
 static const char* get_option(const char* options, const char* option_name)
@@ -84,13 +93,11 @@ static bool match_option(const char* options, const char* option_name)
 
 static void parse_options(struct exfat* ef, const char* options)
 {
-       int sys_umask = umask(0);
        int opt_umask;
 
-       umask(sys_umask); /* restore umask */
-       opt_umask = get_int_option(options, "umask", 8, sys_umask);
-       ef->dmask = get_int_option(options, "dmask", 8, opt_umask) & 0777;
-       ef->fmask = get_int_option(options, "fmask", 8, opt_umask) & 0777;
+       opt_umask = get_int_option(options, "umask", 8, 0);
+       ef->dmask = get_int_option(options, "dmask", 8, opt_umask);
+       ef->fmask = get_int_option(options, "fmask", 8, opt_umask);
 
        ef->uid = get_int_option(options, "uid", 10, geteuid());
        ef->gid = get_int_option(options, "gid", 10, getegid());
@@ -208,6 +215,23 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
                exfat_error("exFAT file system is not found");
                return -EIO;
        }
+       /* sector cannot be smaller than 512 bytes */
+       if (ef->sb->sector_bits < 9)
+       {
+               exfat_close(ef->dev);
+               exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
+               free(ef->sb);
+               return -EIO;
+       }
+       /* officially exFAT supports cluster size up to 32 MB */
+       if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
+       {
+               exfat_close(ef->dev);
+               exfat_error("too big cluster size: 2^(%hhd+%hhd)",
+                               ef->sb->sector_bits, ef->sb->spc_bits);
+               free(ef->sb);
+               return -EIO;
+       }
        ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
        if (ef->zero_cluster == NULL)
        {
@@ -242,27 +266,15 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
                free(ef->sb);
                return -EIO;
        }
-       /* officially exFAT supports cluster size up to 32 MB */
-       if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
-       {
-               free(ef->zero_cluster);
-               exfat_close(ef->dev);
-               exfat_error("too big cluster size: 2^%d",
-                               (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
-               free(ef->sb);
-               return -EIO;
-       }
        if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
                        exfat_get_size(ef->dev))
        {
-               free(ef->zero_cluster);
-               exfat_error("file system is larger than underlying device: "
+               /* this can cause I/O errors later but we don't fail mounting to let
+                  user rescue data */
+               exfat_warn("file system is larger than underlying device: "
                                "%"PRIu64" > %"PRIu64,
                                le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
                                exfat_get_size(ef->dev));
-               exfat_close(ef->dev);
-               free(ef->sb);
-               return -EIO;
        }
 
        ef->root = malloc(sizeof(struct exfat_node));