X-Git-Url: https://git.sven.stormbind.net/?p=sven%2Fexfat-utils.git;a=blobdiff_plain;f=libexfat%2Fmount.c;h=4284aee676fd43105363eafd4bc7e5063f4fb45e;hp=2ebf43625315701e99eba3a543250420a44ce60c;hb=HEAD;hpb=f77812e8b678b8bf620bfbf33882139997ccda34

diff --git a/libexfat/mount.c b/libexfat/mount.c
index 2ebf436..4284aee 100644
--- 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) 2010-2018  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(*ef->sb, 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)
@@ -84,27 +93,38 @@ 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());
 
 	ef->noatime = match_option(options, "noatime");
+
+	switch (get_int_option(options, "repair", 10, 0))
+	{
+	case 1:
+		ef->repair = EXFAT_REPAIR_ASK;
+		break;
+	case 2:
+		ef->repair = EXFAT_REPAIR_YES;
+		break;
+	default:
+		ef->repair = EXFAT_REPAIR_NO;
+		break;
+	}
 }
 
-static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
-		off_t sector_size)
+static bool verify_vbr_checksum(const struct exfat* ef, void* sector)
 {
+	off_t sector_size = SECTOR_SIZE(*ef->sb);
 	uint32_t vbr_checksum;
 	int i;
 
-	if (exfat_pread(dev, sector, sector_size, 0) < 0)
+	if (exfat_pread(ef->dev, sector, sector_size, 0) < 0)
 	{
 		exfat_error("failed to read boot sector");
 		return false;
@@ -112,7 +132,7 @@ static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
 	vbr_checksum = exfat_vbr_start_checksum(sector, sector_size);
 	for (i = 1; i < 11; i++)
 	{
-		if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+		if (exfat_pread(ef->dev, sector, sector_size, i * sector_size) < 0)
 		{
 			exfat_error("failed to read VBR sector");
 			return false;
@@ -120,7 +140,7 @@ static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
 		vbr_checksum = exfat_vbr_add_checksum(sector, sector_size,
 				vbr_checksum);
 	}
-	if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+	if (exfat_pread(ef->dev, sector, sector_size, i * sector_size) < 0)
 	{
 		exfat_error("failed to read VBR checksum sector");
 		return false;
@@ -130,7 +150,8 @@ static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
 		{
 			exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
 					le32_to_cpu(((const le32_t*) sector)[i]), vbr_checksum);
-			return false;
+			if (!EXFAT_REPAIR(invalid_vbr_checksum, ef, sector, vbr_checksum))
+				return false;
 		}
 	return true;
 }
@@ -158,6 +179,22 @@ static int prepare_super_block(const struct exfat* ef)
 	return commit_super_block(ef);
 }
 
+static void exfat_free(struct exfat* ef)
+{
+	exfat_close(ef->dev);	/* first of all, close the descriptor */
+	ef->dev = NULL;			/* struct exfat_dev is freed by exfat_close() */
+	free(ef->root);
+	ef->root = NULL;
+	free(ef->zero_cluster);
+	ef->zero_cluster = NULL;
+	free(ef->cmap.chunk);
+	ef->cmap.chunk = NULL;
+	free(ef->upcase);
+	ef->upcase = NULL;
+	free(ef->sb);
+	ef->sb = NULL;
+}
+
 int exfat_mount(struct exfat* ef, const char* spec, const char* options)
 {
 	int rc;
@@ -188,104 +225,103 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
 	ef->sb = malloc(sizeof(struct exfat_super_block));
 	if (ef->sb == NULL)
 	{
-		exfat_close(ef->dev);
 		exfat_error("failed to allocate memory for the super block");
+		exfat_free(ef);
 		return -ENOMEM;
 	}
 	memset(ef->sb, 0, sizeof(struct exfat_super_block));
 
 	if (exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
 	{
-		exfat_close(ef->dev);
-		free(ef->sb);
 		exfat_error("failed to read boot sector");
+		exfat_free(ef);
 		return -EIO;
 	}
 	if (memcmp(ef->sb->oem_name, "EXFAT   ", 8) != 0)
 	{
-		exfat_close(ef->dev);
-		free(ef->sb);
 		exfat_error("exFAT file system is not found");
+		exfat_free(ef);
+		return -EIO;
+	}
+	/* sector cannot be smaller than 512 bytes */
+	if (ef->sb->sector_bits < 9)
+	{
+		exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
+		exfat_free(ef);
+		return -EIO;
+	}
+	/* officially exFAT supports cluster size up to 32 MB */
+	if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
+	{
+		exfat_error("too big cluster size: 2^(%hhd+%hhd)",
+				ef->sb->sector_bits, ef->sb->spc_bits);
+		exfat_free(ef);
 		return -EIO;
 	}
 	ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
 	if (ef->zero_cluster == NULL)
 	{
-		exfat_close(ef->dev);
-		free(ef->sb);
 		exfat_error("failed to allocate zero sector");
+		exfat_free(ef);
 		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)))
+	if (!verify_vbr_checksum(ef, ef->zero_cluster))
 	{
-		free(ef->zero_cluster);
-		exfat_close(ef->dev);
-		free(ef->sb);
+		exfat_free(ef);
 		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);
+		exfat_free(ef);
 		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);
+		exfat_free(ef);
 		return -EIO;
 	}
-	/* officially exFAT supports cluster size up to 32 MB */
-	if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
+	if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+			exfat_get_size(ef->dev))
 	{
-		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;
+		/* this can cause I/O errors later but we don't fail mounting to let
+		   user rescue data */
+		exfat_warn("file system in sectors is larger than device: "
+				"%"PRIu64" * %d > %"PRIu64,
+				le64_to_cpu(ef->sb->sector_count), SECTOR_SIZE(*ef->sb),
+				exfat_get_size(ef->dev));
 	}
-	if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+	if ((off_t) le32_to_cpu(ef->sb->cluster_count) * CLUSTER_SIZE(*ef->sb) >
 			exfat_get_size(ef->dev))
 	{
-		free(ef->zero_cluster);
-		exfat_error("file system is larger than underlying device: "
-				"%"PRIu64" > %"PRIu64,
-				le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
+		exfat_error("file system in clusters is larger than device: "
+				"%u * %d > %"PRIu64,
+				le32_to_cpu(ef->sb->cluster_count), CLUSTER_SIZE(*ef->sb),
 				exfat_get_size(ef->dev));
-		exfat_close(ef->dev);
-		free(ef->sb);
+		exfat_free(ef);
 		return -EIO;
 	}
 
 	ef->root = malloc(sizeof(struct exfat_node));
 	if (ef->root == NULL)
 	{
-		free(ef->zero_cluster);
-		exfat_close(ef->dev);
-		free(ef->sb);
 		exfat_error("failed to allocate root node");
+		exfat_free(ef);
 		return -ENOMEM;
 	}
 	memset(ef->root, 0, sizeof(struct exfat_node));
-	ef->root->flags = EXFAT_ATTRIB_DIR;
+	ef->root->attrib = EXFAT_ATTRIB_DIR;
 	ef->root->start_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
 	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);
+		exfat_free(ef);
 		return -EIO;
 	}
 	/* exFAT does not have time attributes for the root directory */
@@ -316,10 +352,7 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
 error:
 	exfat_put_node(ef, ef->root);
 	exfat_reset_cache(ef);
-	free(ef->root);
-	free(ef->zero_cluster);
-	exfat_close(ef->dev);
-	free(ef->sb);
+	exfat_free(ef);
 	return -EIO;
 }
 
@@ -347,21 +380,10 @@ static void finalize_super_block(struct exfat* ef)
 
 void exfat_unmount(struct exfat* ef)
 {
-	exfat_flush(ef);	/* ignore return code */
+	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);
-	ef->root = NULL;
 	finalize_super_block(ef);
-	exfat_close(ef->dev);	/* close descriptor immediately after fsync */
-	ef->dev = NULL;
-	free(ef->zero_cluster);
-	ef->zero_cluster = NULL;
-	free(ef->cmap.chunk);
-	ef->cmap.chunk = NULL;
-	free(ef->sb);
-	ef->sb = NULL;
-	free(ef->upcase);
-	ef->upcase = NULL;
-	ef->upcase_chars = 0;
+	exfat_free(ef);			/* will close the descriptor */
 }