Imported Upstream version 1.2.1

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

diff --git a/libexfat/mount.c b/libexfat/mount.c
index 521b539085d7fdf52dd7a5bcd83f7f40efd4f447..f1fb01a9a88c8ee20eb3730c6669ee905cfbfcd3 100644 (file)
--- a/libexfat/mount.c
+++ b/libexfat/mount.c
@@ -2,11 +2,12 @@
        mount.c (22.10.09)
        exFAT file system implementation library.
 
        mount.c (22.10.09)
        exFAT file system implementation library.
 

-       Copyright (C) 2009, 2010  Andrew Nayenko
+       Free exFAT implementation.
+       Copyright (C) 2010-2015  Andrew Nayenko

 
 

-       This program is free software: you can redistribute it and/or modify
+       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
        it under the terms of the GNU General Public License as published by

-       the Free Software Foundation, either version 3 of the License, or
+       the Free Software Foundation, either version 2 of the License, or

        (at your option) any later version.
 
        This program is distributed in the hope that it will be useful,
        (at your option) any later version.
 
        This program is distributed in the hope that it will be useful,


@@ -14,30 +15,47 @@
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.
 
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.
 

-       You should have received a copy of the GNU General Public License
-       along with this program.  If not, see <http://www.gnu.org/licenses/>.
+       You should have received a copy of the GNU General Public License along
+       with this program; if not, write to the Free Software Foundation, Inc.,
+       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */
 
 #include "exfat.h"
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
 */
 
 #include "exfat.h"
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>

+#include <inttypes.h>

 #include <unistd.h>
 #include <sys/types.h>
 
 static uint64_t rootdir_size(const struct exfat* ef)
 {
 #include <unistd.h>
 #include <sys/types.h>
 
 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);
 
        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);
                rootdir_cluster = exfat_next_cluster(ef, ef->root, rootdir_cluster);

+               clusters++;

        }
        }

-       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)
 }
 
 static const char* get_option(const char* options, const char* option_name)


@@ -61,7 +79,7 @@ static int get_int_option(const char* options, const char* option_name,
        return strtol(p, NULL, base);
 }
 
        return strtol(p, NULL, base);
 }
 

-static int match_option(const char* options, const char* option_name)
+static bool match_option(const char* options, const char* option_name)

 {
        const char* p;
        size_t length = strlen(option_name);
 {
        const char* p;
        size_t length = strlen(option_name);


@@ -69,55 +87,68 @@ static int match_option(const char* options, const char* option_name)
        for (p = strstr(options, option_name); p; p = strstr(p + 1, option_name))
                if ((p == options || p[-1] == ',') &&
                                (p[length] == ',' || p[length] == '\0'))
        for (p = strstr(options, option_name); p; p = strstr(p + 1, option_name))
                if ((p == options || p[-1] == ',') &&
                                (p[length] == ',' || p[length] == '\0'))

-                       return 1;
-       return 0;
+                       return true;
+       return false;

 }
 
 static void parse_options(struct exfat* ef, const char* options)
 {
 }
 
 static void parse_options(struct exfat* ef, const char* options)
 {

-       int sys_umask = umask(0);

        int opt_umask;
 
        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());
 
 
        ef->uid = get_int_option(options, "uid", 10, geteuid());
        ef->gid = get_int_option(options, "gid", 10, getegid());
 

-       ef->ro = match_option(options, "ro");

        ef->noatime = match_option(options, "noatime");
 }
 
        ef->noatime = match_option(options, "noatime");
 }
 

-static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
+static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,

                off_t sector_size)
 {
        uint32_t vbr_checksum;
        int i;
 
                off_t sector_size)
 {
        uint32_t vbr_checksum;
        int i;
 

-       exfat_pread(dev, sector, sector_size, 0);
+       if (exfat_pread(dev, sector, sector_size, 0) < 0)
+       {
+               exfat_error("failed to read boot sector");
+               return false;
+       }

        vbr_checksum = exfat_vbr_start_checksum(sector, sector_size);
        for (i = 1; i < 11; i++)
        {
        vbr_checksum = exfat_vbr_start_checksum(sector, sector_size);
        for (i = 1; i < 11; i++)
        {

-               exfat_pread(dev, sector, sector_size, i * sector_size);
+               if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+               {
+                       exfat_error("failed to read VBR sector");
+                       return false;
+               }

                vbr_checksum = exfat_vbr_add_checksum(sector, sector_size,
                                vbr_checksum);
        }
                vbr_checksum = exfat_vbr_add_checksum(sector, sector_size,
                                vbr_checksum);
        }

-       exfat_pread(dev, sector, sector_size, i * sector_size);
+       if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+       {
+               exfat_error("failed to read VBR checksum sector");
+               return false;
+       }

        for (i = 0; i < sector_size / sizeof(vbr_checksum); i++)
                if (le32_to_cpu(((const le32_t*) sector)[i]) != vbr_checksum)
                {
                        exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
                                        le32_to_cpu(((const le32_t*) sector)[i]), vbr_checksum);
        for (i = 0; i < sector_size / sizeof(vbr_checksum); i++)
                if (le32_to_cpu(((const le32_t*) sector)[i]) != vbr_checksum)
                {
                        exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
                                        le32_to_cpu(((const le32_t*) sector)[i]), vbr_checksum);

-                       return 1;
+                       return false;

                }
                }

-       return 0;
+       return true;

 }
 
 static int commit_super_block(const struct exfat* ef)
 {
 }
 
 static int commit_super_block(const struct exfat* ef)
 {

-       exfat_pwrite(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0);
+       if (exfat_pwrite(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
+       {
+               exfat_error("failed to write super block");
+               return 1;
+       }

        return exfat_fsync(ef->dev);
 }
 
        return exfat_fsync(ef->dev);
 }
 


@@ -137,22 +168,28 @@ static int prepare_super_block(const struct exfat* ef)
 int exfat_mount(struct exfat* ef, const char* spec, const char* options)
 {
        int rc;
 int exfat_mount(struct exfat* ef, const char* spec, const char* options)
 {
        int rc;

+       enum exfat_mode mode;

 
        exfat_tzset();
        memset(ef, 0, sizeof(struct exfat));
 
        parse_options(ef, options);
 
 
        exfat_tzset();
        memset(ef, 0, sizeof(struct exfat));
 
        parse_options(ef, options);
 

-       ef->dev = exfat_open(spec, ef->ro);
+       if (match_option(options, "ro"))
+               mode = EXFAT_MODE_RO;
+       else if (match_option(options, "ro_fallback"))
+               mode = EXFAT_MODE_ANY;
+       else
+               mode = EXFAT_MODE_RW;
+       ef->dev = exfat_open(spec, mode);

        if (ef->dev == NULL)
        if (ef->dev == NULL)

+               return -EIO;
+       if (exfat_get_mode(ef->dev) == EXFAT_MODE_RO)

        {
        {

-               if (ef->ro || !match_option(options, "ro_fallback"))
-                       return -EIO;
-               ef->dev = exfat_open(spec, 1);
-               if (ef->dev == NULL)
-                       return -EIO;
-               exfat_warn("device is write-protected, mounting read-only");
-               ef->ro_fallback = ef->ro = 1;
+               if (mode == EXFAT_MODE_ANY)
+                       ef->ro = -1;
+               else
+                       ef->ro = 1;

        }
 
        ef->sb = malloc(sizeof(struct exfat_super_block));
        }
 
        ef->sb = malloc(sizeof(struct exfat_super_block));


@@ -164,39 +201,37 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
        }
        memset(ef->sb, 0, sizeof(struct exfat_super_block));
 
        }
        memset(ef->sb, 0, sizeof(struct exfat_super_block));
 

-       exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0);
-       if (memcmp(ef->sb->oem_name, "EXFAT   ", 8) != 0)
+       if (exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)

        {
                exfat_close(ef->dev);
                free(ef->sb);
        {
                exfat_close(ef->dev);
                free(ef->sb);

-               exfat_error("exFAT file system is not found");
+               exfat_error("failed to read boot sector");

                return -EIO;
        }
                return -EIO;
        }

-       if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+       if (memcmp(ef->sb->oem_name, "EXFAT   ", 8) != 0)

        {
                exfat_close(ef->dev);
        {
                exfat_close(ef->dev);

-               exfat_error("unsupported exFAT version: %hhu.%hhu",
-                               ef->sb->version.major, ef->sb->version.minor);

                free(ef->sb);
                free(ef->sb);

+               exfat_error("exFAT file system is not found");

                return -EIO;
        }
                return -EIO;
        }

-       if (ef->sb->fat_count != 1)
+       /* sector cannot be smaller than 512 bytes */
+       if (ef->sb->sector_bits < 9)

        {
                exfat_close(ef->dev);
        {
                exfat_close(ef->dev);

+               exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);

                free(ef->sb);
                free(ef->sb);

-               exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);

                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);
                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);
                free(ef->sb);

-               exfat_error("too big cluster size: 2^%d",
-                               (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);

                return -EIO;
        }
                return -EIO;
        }

-

        ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
        if (ef->zero_cluster == NULL)
        {
        ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
        if (ef->zero_cluster == NULL)
        {


@@ -206,8 +241,7 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
                return -ENOMEM;
        }
        /* use zero_cluster as a temporary buffer for VBR checksum verification */
                return -ENOMEM;
        }
        /* use zero_cluster as a temporary buffer for VBR checksum verification */

-       if (verify_vbr_checksum(ef->dev, ef->zero_cluster,
-                       SECTOR_SIZE(*ef->sb)) != 0)
+       if (!verify_vbr_checksum(ef->dev, ef->zero_cluster, SECTOR_SIZE(*ef->sb)))

        {
                free(ef->zero_cluster);
                exfat_close(ef->dev);
        {
                free(ef->zero_cluster);
                exfat_close(ef->dev);


@@ -215,6 +249,33 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
                return -EIO;
        }
        memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
                return -EIO;
        }
        memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));

+       if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+       {
+               free(ef->zero_cluster);
+               exfat_close(ef->dev);
+               exfat_error("unsupported exFAT version: %hhu.%hhu",
+                               ef->sb->version.major, ef->sb->version.minor);
+               free(ef->sb);
+               return -EIO;
+       }
+       if (ef->sb->fat_count != 1)
+       {
+               free(ef->zero_cluster);
+               exfat_close(ef->dev);
+               exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
+               free(ef->sb);
+               return -EIO;
+       }
+       if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+                       exfat_get_size(ef->dev))
+       {
+               /* 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));
+       }

 
        ef->root = malloc(sizeof(struct exfat_node));
        if (ef->root == NULL)
 
        ef->root = malloc(sizeof(struct exfat_node));
        if (ef->root == NULL)


@@ -231,6 +292,14 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
        ef->root->fptr_cluster = ef->root->start_cluster;
        ef->root->name[0] = cpu_to_le16('\0');
        ef->root->size = rootdir_size(ef);
        ef->root->fptr_cluster = ef->root->start_cluster;
        ef->root->name[0] = cpu_to_le16('\0');
        ef->root->size = rootdir_size(ef);

+       if (ef->root->size == 0)
+       {
+               free(ef->root);
+               free(ef->zero_cluster);
+               exfat_close(ef->dev);
+               free(ef->sb);
+               return -EIO;
+       }

        /* exFAT does not have time attributes for the root directory */
        ef->root->mtime = 0;
        ef->root->atime = 0;
        /* exFAT does not have time attributes for the root directory */
        ef->root->mtime = 0;
        ef->root->atime = 0;


@@ -285,11 +354,12 @@ static void finalize_super_block(struct exfat* ef)
                ef->sb->allocated_percent = ((total - free) * 100 + total / 2) / total;
        }
 
                ef->sb->allocated_percent = ((total - free) * 100 + total / 2) / total;
        }
 

-       commit_super_block(ef);
+       commit_super_block(ef); /* ignore return code */

 }
 
 void exfat_unmount(struct exfat* ef)
 {
 }
 
 void exfat_unmount(struct exfat* ef)
 {

+       exfat_flush(ef);        /* ignore return code */

        exfat_put_node(ef, ef->root);
        exfat_reset_cache(ef);
        free(ef->root);
        exfat_put_node(ef, ef->root);
        exfat_reset_cache(ef);
        free(ef->root);