X-Git-Url: https://git.sven.stormbind.net/?a=blobdiff_plain;f=libexfat%2Fmount.c;h=b1ce6543884d3155b4552863781e3c79c4c2bba2;hb=3c458260fcbb2e5f730215972d275f03a40415c3;hp=521b539085d7fdf52dd7a5bcd83f7f40efd4f447;hpb=9799d681703e3a63dbbf876c16c9bb51b20c8fab;p=sven%2Fexfat-utils.git
diff --git a/libexfat/mount.c b/libexfat/mount.c
index 521b539..b1ce654 100644
--- a/libexfat/mount.c
+++ b/libexfat/mount.c
@@ -2,11 +2,12 @@
mount.c (22.10.09)
exFAT file system implementation library.
- Copyright (C) 2009, 2010 Andrew Nayenko
+ Free exFAT implementation.
+ Copyright (C) 2010-2016 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
- 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,
@@ -14,30 +15,47 @@
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 .
+ 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
#include
#include
+#include
#include
#include
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++;
}
- 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)
@@ -61,7 +79,7 @@ static int get_int_option(const char* options, const char* option_name,
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);
@@ -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'))
- return 1;
- return 0;
+ return true;
+ return false;
}
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());
- ef->ro = match_option(options, "ro");
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;
- 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++)
{
- 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);
}
- 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);
- return 1;
+ return false;
}
- return 0;
+ return true;
}
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);
}
@@ -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;
+ enum exfat_mode mode;
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)
+ 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));
@@ -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));
- 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_error("exFAT file system is not found");
+ exfat_error("failed to read boot sector");
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_error("unsupported exFAT version: %hhu.%hhu",
- ef->sb->version.major, ef->sb->version.minor);
free(ef->sb);
+ exfat_error("exFAT file system is not found");
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_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
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);
+ exfat_error("too big cluster size: 2^(%hhd+%hhd)",
+ ef->sb->sector_bits, ef->sb->spc_bits);
free(ef->sb);
- exfat_error("too big cluster size: 2^%d",
- (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
return -EIO;
}
-
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 */
- 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);
@@ -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));
+ 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)
@@ -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);
+ 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;
@@ -285,11 +354,13 @@ static void finalize_super_block(struct exfat* ef)
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)
{
+ exfat_flush_nodes(ef); /* ignore return code */
+ exfat_flush(ef); /* ignore return code */
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
@@ -305,5 +376,4 @@ void exfat_unmount(struct exfat* ef)
ef->sb = NULL;
free(ef->upcase);
ef->upcase = NULL;
- ef->upcase_chars = 0;
}