Aggregate PBR related definitions and redefine as "boot_sector" to comply
with the exFAT specification.
And, rename variable names including 'pbr'.
Signed-off-by: Tetsuhiro Kohada <[email protected]>
---
Changes in v2:
- rebase with patch 'optimize dir-cache' applied
fs/exfat/exfat_fs.h | 2 +-
fs/exfat/exfat_raw.h | 79 +++++++++++++++--------------------------
fs/exfat/super.c | 84 ++++++++++++++++++++++----------------------
3 files changed, 72 insertions(+), 93 deletions(-)
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 5caad1380818..9673e2d31045 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -227,7 +227,7 @@ struct exfat_sb_info {
unsigned int root_dir; /* root dir cluster */
unsigned int dentries_per_clu; /* num of dentries per cluster */
unsigned int vol_flag; /* volume dirty flag */
- struct buffer_head *pbr_bh; /* buffer_head of PBR sector */
+ struct buffer_head *boot_bh; /* buffer_head of BOOT sector */
unsigned int map_clu; /* allocation bitmap start cluster */
unsigned int map_sectors; /* num of allocation bitmap sectors */
diff --git a/fs/exfat/exfat_raw.h b/fs/exfat/exfat_raw.h
index 8d6c64a7546d..b373dc4e099f 100644
--- a/fs/exfat/exfat_raw.h
+++ b/fs/exfat/exfat_raw.h
@@ -8,7 +8,8 @@
#include <linux/types.h>
-#define PBR_SIGNATURE 0xAA55
+#define BOOT_SIGNATURE 0xAA55
+#define EXBOOT_SIGNATURE 0xAA550000
#define EXFAT_MAX_FILE_LEN 255
@@ -55,7 +56,7 @@
/* checksum types */
#define CS_DIR_ENTRY 0
-#define CS_PBR_SECTOR 1
+#define CS_BOOT_SECTOR 1
#define CS_DEFAULT 2
/* file attributes */
@@ -69,57 +70,35 @@
#define ATTR_RWMASK (ATTR_HIDDEN | ATTR_SYSTEM | ATTR_VOLUME | \
ATTR_SUBDIR | ATTR_ARCHIVE)
-#define PBR64_JUMP_BOOT_LEN 3
-#define PBR64_OEM_NAME_LEN 8
-#define PBR64_RESERVED_LEN 53
+#define BOOTSEC_JUMP_BOOT_LEN 3
+#define BOOTSEC_OEM_NAME_LEN 8
+#define BOOTSEC_OLDBPB_LEN 53
#define EXFAT_FILE_NAME_LEN 15
-/* EXFAT BIOS parameter block (64 bytes) */
-struct bpb64 {
- __u8 jmp_boot[PBR64_JUMP_BOOT_LEN];
- __u8 oem_name[PBR64_OEM_NAME_LEN];
- __u8 res_zero[PBR64_RESERVED_LEN];
-} __packed;
-
-/* EXFAT EXTEND BIOS parameter block (56 bytes) */
-struct bsx64 {
- __le64 vol_offset;
- __le64 vol_length;
- __le32 fat_offset;
- __le32 fat_length;
- __le32 clu_offset;
- __le32 clu_count;
- __le32 root_cluster;
- __le32 vol_serial;
- __u8 fs_version[2];
- __le16 vol_flags;
- __u8 sect_size_bits;
- __u8 sect_per_clus_bits;
- __u8 num_fats;
- __u8 phy_drv_no;
- __u8 perc_in_use;
- __u8 reserved2[7];
-} __packed;
-
-/* EXFAT PBR[BPB+BSX] (120 bytes) */
-struct pbr64 {
- struct bpb64 bpb;
- struct bsx64 bsx;
-} __packed;
-
-/* Common PBR[Partition Boot Record] (512 bytes) */
-struct pbr {
- union {
- __u8 raw[64];
- struct bpb64 f64;
- } bpb;
- union {
- __u8 raw[56];
- struct bsx64 f64;
- } bsx;
- __u8 boot_code[390];
- __le16 signature;
+/* EXFAT: Main and Backup Boot Sector (512 bytes) */
+struct boot_sector {
+ __u8 jmp_boot[BOOTSEC_JUMP_BOOT_LEN];
+ __u8 oem_name[BOOTSEC_OEM_NAME_LEN];
+ __u8 must_be_zero[BOOTSEC_OLDBPB_LEN];
+ __le64 partition_offset;
+ __le64 vol_length;
+ __le32 fat_offset;
+ __le32 fat_length;
+ __le32 clu_offset;
+ __le32 clu_count;
+ __le32 root_cluster;
+ __le32 vol_serial;
+ __u8 fs_revision[2];
+ __le16 vol_flags;
+ __u8 sect_size_bits;
+ __u8 sect_per_clus_bits;
+ __u8 num_fats;
+ __u8 drv_sel;
+ __u8 percent_in_use;
+ __u8 reserved[7];
+ __u8 boot_code[390];
+ __le16 signature;
} __packed;
struct exfat_dentry {
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index c1f47f4071a8..e60d28e73ff0 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -49,7 +49,7 @@ static void exfat_put_super(struct super_block *sb)
sync_blockdev(sb->s_bdev);
exfat_set_vol_flags(sb, VOL_CLEAN);
exfat_free_bitmap(sbi);
- brelse(sbi->pbr_bh);
+ brelse(sbi->boot_bh);
mutex_unlock(&sbi->s_lock);
call_rcu(&sbi->rcu, exfat_delayed_free);
@@ -101,7 +101,7 @@ static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
- struct pbr64 *bpb = (struct pbr64 *)sbi->pbr_bh->b_data;
+ struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
bool sync;
/* flags are not changed */
@@ -116,18 +116,18 @@ int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
if (sb_rdonly(sb))
return 0;
- bpb->bsx.vol_flags = cpu_to_le16(new_flag);
+ p_boot->vol_flags = cpu_to_le16(new_flag);
- if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->pbr_bh))
+ if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->boot_bh))
sync = true;
else
sync = false;
- set_buffer_uptodate(sbi->pbr_bh);
- mark_buffer_dirty(sbi->pbr_bh);
+ set_buffer_uptodate(sbi->boot_bh);
+ mark_buffer_dirty(sbi->boot_bh);
if (sync)
- sync_dirty_buffer(sbi->pbr_bh);
+ sync_dirty_buffer(sbi->boot_bh);
return 0;
}
@@ -366,13 +366,14 @@ static int exfat_read_root(struct inode *inode)
return 0;
}
-static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb)
+static struct boot_sector *exfat_read_boot_with_logical_sector(
+ struct super_block *sb)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
- struct pbr *p_pbr = (struct pbr *) (sbi->pbr_bh)->b_data;
+ struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
unsigned short logical_sect = 0;
- logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;
+ logical_sect = 1 << p_boot->sect_size_bits;
if (!is_power_of_2(logical_sect) ||
logical_sect < 512 || logical_sect > 4096) {
@@ -387,49 +388,48 @@ static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb)
}
if (logical_sect > sb->s_blocksize) {
- brelse(sbi->pbr_bh);
- sbi->pbr_bh = NULL;
+ brelse(sbi->boot_bh);
+ sbi->boot_bh = NULL;
if (!sb_set_blocksize(sb, logical_sect)) {
exfat_err(sb, "unable to set blocksize %u",
logical_sect);
return NULL;
}
- sbi->pbr_bh = sb_bread(sb, 0);
- if (!sbi->pbr_bh) {
+ sbi->boot_bh = sb_bread(sb, 0);
+ if (!sbi->boot_bh) {
exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
sb->s_blocksize);
return NULL;
}
- p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
+ p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
}
- return p_pbr;
+ return p_boot;
}
/* mount the file system volume */
static int __exfat_fill_super(struct super_block *sb)
{
int ret;
- struct pbr *p_pbr;
- struct pbr64 *p_bpb;
+ struct boot_sector *p_boot;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
/* set block size to read super block */
sb_min_blocksize(sb, 512);
/* read boot sector */
- sbi->pbr_bh = sb_bread(sb, 0);
- if (!sbi->pbr_bh) {
+ sbi->boot_bh = sb_bread(sb, 0);
+ if (!sbi->boot_bh) {
exfat_err(sb, "unable to read boot sector");
return -EIO;
}
/* PRB is read */
- p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
+ p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
- /* check the validity of PBR */
- if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
+ /* check the validity of BOOT */
+ if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
exfat_err(sb, "invalid boot record signature");
ret = -EINVAL;
goto free_bh;
@@ -437,8 +437,8 @@ static int __exfat_fill_super(struct super_block *sb)
/* check logical sector size */
- p_pbr = exfat_read_pbr_with_logical_sector(sb);
- if (!p_pbr) {
+ p_boot = exfat_read_boot_with_logical_sector(sb);
+ if (!p_boot) {
ret = -EIO;
goto free_bh;
}
@@ -447,43 +447,43 @@ static int __exfat_fill_super(struct super_block *sb)
* res_zero field must be filled with zero to prevent mounting
* from FAT volume.
*/
- if (memchr_inv(p_pbr->bpb.f64.res_zero, 0,
- sizeof(p_pbr->bpb.f64.res_zero))) {
+ if (memchr_inv(p_boot->must_be_zero, 0,
+ sizeof(p_boot->must_be_zero))) {
ret = -EINVAL;
goto free_bh;
}
- p_bpb = (struct pbr64 *)p_pbr;
- if (!p_bpb->bsx.num_fats) {
+ p_boot = (struct boot_sector *)p_boot;
+ if (!p_boot->num_fats) {
exfat_err(sb, "bogus number of FAT structure");
ret = -EINVAL;
goto free_bh;
}
- sbi->sect_per_clus = 1 << p_bpb->bsx.sect_per_clus_bits;
- sbi->sect_per_clus_bits = p_bpb->bsx.sect_per_clus_bits;
+ sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
+ sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
sbi->cluster_size = 1 << sbi->cluster_size_bits;
- sbi->num_FAT_sectors = le32_to_cpu(p_bpb->bsx.fat_length);
- sbi->FAT1_start_sector = le32_to_cpu(p_bpb->bsx.fat_offset);
- sbi->FAT2_start_sector = p_bpb->bsx.num_fats == 1 ?
+ sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
+ sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
+ sbi->FAT2_start_sector = p_boot->num_fats == 1 ?
sbi->FAT1_start_sector :
sbi->FAT1_start_sector + sbi->num_FAT_sectors;
- sbi->data_start_sector = le32_to_cpu(p_bpb->bsx.clu_offset);
- sbi->num_sectors = le64_to_cpu(p_bpb->bsx.vol_length);
+ sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
+ sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
/* because the cluster index starts with 2 */
- sbi->num_clusters = le32_to_cpu(p_bpb->bsx.clu_count) +
+ sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
EXFAT_RESERVED_CLUSTERS;
- sbi->root_dir = le32_to_cpu(p_bpb->bsx.root_cluster);
+ sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
sbi->dentries_per_clu = 1 <<
(sbi->cluster_size_bits - DENTRY_SIZE_BITS);
- sbi->vol_flag = le16_to_cpu(p_bpb->bsx.vol_flags);
+ sbi->vol_flag = le16_to_cpu(p_boot->vol_flags);
sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
- if (le16_to_cpu(p_bpb->bsx.vol_flags) & VOL_DIRTY) {
+ if (le16_to_cpu(p_boot->vol_flags) & VOL_DIRTY) {
sbi->vol_flag |= VOL_DIRTY;
exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
}
@@ -517,7 +517,7 @@ static int __exfat_fill_super(struct super_block *sb)
free_upcase_table:
exfat_free_upcase_table(sbi);
free_bh:
- brelse(sbi->pbr_bh);
+ brelse(sbi->boot_bh);
return ret;
}
@@ -608,7 +608,7 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
free_table:
exfat_free_upcase_table(sbi);
exfat_free_bitmap(sbi);
- brelse(sbi->pbr_bh);
+ brelse(sbi->boot_bh);
check_nls_io:
unload_nls(sbi->nls_io);
--
2.25.1
Separate the boot sector analysis to read_boot_sector().
Furthermore, add a strict consistency check, because overlapping areas
can cause serious corruption.
Signed-off-by: Tetsuhiro Kohada <[email protected]>
---
Changes in v2:
- rebase with patch 'optimize dir-cache' applied
fs/exfat/exfat_raw.h | 1 +
fs/exfat/super.c | 96 +++++++++++++++++++++++---------------------
2 files changed, 52 insertions(+), 45 deletions(-)
diff --git a/fs/exfat/exfat_raw.h b/fs/exfat/exfat_raw.h
index b373dc4e099f..65f884785192 100644
--- a/fs/exfat/exfat_raw.h
+++ b/fs/exfat/exfat_raw.h
@@ -15,6 +15,7 @@
#define VOL_CLEAN 0x0000
#define VOL_DIRTY 0x0002
+#define ERR_MEDIUM 0x0004
#define EXFAT_EOF_CLUSTER 0xFFFFFFFFu
#define EXFAT_BAD_CLUSTER 0xFFFFFFF7u
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index e60d28e73ff0..95909b4d5e75 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -366,25 +366,20 @@ static int exfat_read_root(struct inode *inode)
return 0;
}
-static struct boot_sector *exfat_read_boot_with_logical_sector(
- struct super_block *sb)
+static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
- struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
- unsigned short logical_sect = 0;
-
- logical_sect = 1 << p_boot->sect_size_bits;
if (!is_power_of_2(logical_sect) ||
logical_sect < 512 || logical_sect > 4096) {
exfat_err(sb, "bogus logical sector size %u", logical_sect);
- return NULL;
+ return -EIO;
}
if (logical_sect < sb->s_blocksize) {
exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
logical_sect);
- return NULL;
+ return -EIO;
}
if (logical_sect > sb->s_blocksize) {
@@ -394,24 +389,20 @@ static struct boot_sector *exfat_read_boot_with_logical_sector(
if (!sb_set_blocksize(sb, logical_sect)) {
exfat_err(sb, "unable to set blocksize %u",
logical_sect);
- return NULL;
+ return -EIO;
}
sbi->boot_bh = sb_bread(sb, 0);
if (!sbi->boot_bh) {
exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
sb->s_blocksize);
- return NULL;
+ return -EIO;
}
-
- p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
}
- return p_boot;
+ return 0;
}
-/* mount the file system volume */
-static int __exfat_fill_super(struct super_block *sb)
+static int exfat_read_boot_sector(struct super_block *sb)
{
- int ret;
struct boot_sector *p_boot;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
@@ -424,51 +415,36 @@ static int __exfat_fill_super(struct super_block *sb)
exfat_err(sb, "unable to read boot sector");
return -EIO;
}
-
- /* PRB is read */
p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
/* check the validity of BOOT */
if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
exfat_err(sb, "invalid boot record signature");
- ret = -EINVAL;
- goto free_bh;
- }
-
-
- /* check logical sector size */
- p_boot = exfat_read_boot_with_logical_sector(sb);
- if (!p_boot) {
- ret = -EIO;
- goto free_bh;
+ return -EINVAL;
}
/*
- * res_zero field must be filled with zero to prevent mounting
+ * must_be_zero field must be filled with zero to prevent mounting
* from FAT volume.
*/
- if (memchr_inv(p_boot->must_be_zero, 0,
- sizeof(p_boot->must_be_zero))) {
- ret = -EINVAL;
- goto free_bh;
- }
+ if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
+ return -EINVAL;
- p_boot = (struct boot_sector *)p_boot;
- if (!p_boot->num_fats) {
+ if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
exfat_err(sb, "bogus number of FAT structure");
- ret = -EINVAL;
- goto free_bh;
+ return -EINVAL;
}
sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
- sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
+ sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
+ p_boot->sect_size_bits;
sbi->cluster_size = 1 << sbi->cluster_size_bits;
sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
- sbi->FAT2_start_sector = p_boot->num_fats == 1 ?
- sbi->FAT1_start_sector :
- sbi->FAT1_start_sector + sbi->num_FAT_sectors;
+ sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
+ if (p_boot->num_fats == 2)
+ sbi->FAT2_start_sector += sbi->num_FAT_sectors;
sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
/* because the cluster index starts with 2 */
@@ -483,15 +459,45 @@ static int __exfat_fill_super(struct super_block *sb)
sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
- if (le16_to_cpu(p_boot->vol_flags) & VOL_DIRTY) {
- sbi->vol_flag |= VOL_DIRTY;
- exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
+ /* check consistencies */
+ if (sbi->num_FAT_sectors << p_boot->sect_size_bits <
+ sbi->num_clusters * 4) {
+ exfat_err(sb, "bogus fat length");
+ return -EINVAL;
+ }
+ if (sbi->data_start_sector <
+ sbi->FAT1_start_sector + sbi->num_FAT_sectors * p_boot->num_fats) {
+ exfat_err(sb, "bogus data start sector");
+ return -EINVAL;
}
+ if (sbi->vol_flag & VOL_DIRTY)
+ exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
+ if (sbi->vol_flag & ERR_MEDIUM)
+ exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
/* exFAT file size is limited by a disk volume size */
sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
sbi->cluster_size_bits;
+ /* check logical sector size */
+ if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
+ return -EIO;
+
+ return 0;
+}
+
+/* mount the file system volume */
+static int __exfat_fill_super(struct super_block *sb)
+{
+ int ret;
+ struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+ ret = exfat_read_boot_sector(sb);
+ if (ret) {
+ exfat_err(sb, "failed to read boot sector");
+ goto free_bh;
+ }
+
ret = exfat_create_upcase_table(sb);
if (ret) {
exfat_err(sb, "failed to load upcase table");
--
2.25.1
Add Boot-Regions verification specified in exFAT specification.
Note that the checksum type is strongly related to the raw structure,
so the'u32 'type is used to clarify the number of bits.
Signed-off-by: Tetsuhiro Kohada <[email protected]>
---
Changes in v2:
- rebase with patch 'optimize dir-cache' applied
- just print a warning when invalid exboot-signature detected
- print additional information when invalid boot-checksum detected
fs/exfat/exfat_fs.h | 1 +
fs/exfat/misc.c | 14 +++++++++++++
fs/exfat/super.c | 49 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 64 insertions(+)
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 9673e2d31045..eebbe5a84b2b 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -514,6 +514,7 @@ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
unsigned short exfat_calc_chksum_2byte(void *data, int len,
unsigned short chksum, int type);
+u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync);
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
unsigned int size, unsigned char flags);
diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c
index ab7f88b1f6d3..b82d2dd5bd7c 100644
--- a/fs/exfat/misc.c
+++ b/fs/exfat/misc.c
@@ -151,6 +151,20 @@ unsigned short exfat_calc_chksum_2byte(void *data, int len,
return chksum;
}
+u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type)
+{
+ int i;
+ u8 *c = (u8 *)data;
+
+ for (i = 0; i < len; i++, c++) {
+ if (unlikely(type == CS_BOOT_SECTOR &&
+ (i == 106 || i == 107 || i == 112)))
+ continue;
+ chksum = ((chksum << 31) | (chksum >> 1)) + *c;
+ }
+ return chksum;
+}
+
void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync)
{
set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(sb)->s_state);
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 95909b4d5e75..381f4394f976 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -486,6 +486,49 @@ static int exfat_read_boot_sector(struct super_block *sb)
return 0;
}
+static int exfat_verify_boot_region(struct super_block *sb)
+{
+ struct buffer_head *bh = NULL;
+ u32 chksum = 0, *p_sig, *p_chksum;
+ int sn, i;
+
+ /* read boot sector sub-regions */
+ for (sn = 0; sn < 11; sn++) {
+ bh = sb_bread(sb, sn);
+ if (!bh)
+ return -EIO;
+
+ if (sn != 0 && sn <= 8) {
+ /* extended boot sector sub-regions */
+ p_sig = (u32 *)&bh->b_data[sb->s_blocksize - 4];
+ if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
+ exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
+ sn, le32_to_cpu(*p_sig));
+ }
+
+ chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
+ chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
+ brelse(bh);
+ }
+
+ /* boot checksum sub-regions */
+ bh = sb_bread(sb, sn);
+ if (!bh)
+ return -EIO;
+
+ for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
+ p_chksum = (u32 *)&bh->b_data[i];
+ if (le32_to_cpu(*p_chksum) != chksum) {
+ exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
+ le32_to_cpu(*p_chksum), chksum);
+ brelse(bh);
+ return -EINVAL;
+ }
+ }
+ brelse(bh);
+ return 0;
+}
+
/* mount the file system volume */
static int __exfat_fill_super(struct super_block *sb)
{
@@ -498,6 +541,12 @@ static int __exfat_fill_super(struct super_block *sb)
goto free_bh;
}
+ ret = exfat_verify_boot_region(sb);
+ if (ret) {
+ exfat_err(sb, "invalid boot region");
+ goto free_bh;
+ }
+
ret = exfat_create_upcase_table(sb);
if (ret) {
exfat_err(sb, "failed to load upcase table");
--
2.25.1
To clarify that it is a 16-bit checksum, the parts related to the 16-bit
checksum are renamed and change type to u16.
Furthermore, replace checksum calculation in exfat_load_upcase_table()
with exfat_calc_checksum32().
Signed-off-by: Tetsuhiro Kohada <[email protected]>
---
Changes in v2:
- rebase with patch 'optimize dir-cache' applied
fs/exfat/dir.c | 12 ++++++------
fs/exfat/exfat_fs.h | 5 ++---
fs/exfat/misc.c | 10 ++++------
fs/exfat/nls.c | 19 +++++++------------
4 files changed, 19 insertions(+), 27 deletions(-)
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 2902d285bf20..de43534aa299 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -491,7 +491,7 @@ int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
int ret = 0;
int i, num_entries;
sector_t sector;
- unsigned short chksum;
+ u16 chksum;
struct exfat_dentry *ep, *fep;
struct buffer_head *fbh, *bh;
@@ -500,7 +500,7 @@ int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
return -EIO;
num_entries = fep->dentry.file.num_ext + 1;
- chksum = exfat_calc_chksum_2byte(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
+ chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
for (i = 1; i < num_entries; i++) {
ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL);
@@ -508,7 +508,7 @@ int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
ret = -EIO;
goto release_fbh;
}
- chksum = exfat_calc_chksum_2byte(ep, DENTRY_SIZE, chksum,
+ chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
CS_DEFAULT);
brelse(bh);
}
@@ -593,8 +593,8 @@ void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
for (i = 0; i < es->num_entries; i++) {
ep = exfat_get_dentry_cached(es, i);
- chksum = exfat_calc_chksum_2byte(ep, DENTRY_SIZE, chksum,
- chksum_type);
+ chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
+ chksum_type);
chksum_type = CS_DEFAULT;
}
ep = exfat_get_dentry_cached(es, 0);
@@ -1000,7 +1000,7 @@ int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
}
if (entry_type == TYPE_STREAM) {
- unsigned short name_hash;
+ u16 name_hash;
if (step != DIRENT_STEP_STRM) {
step = DIRENT_STEP_FILE;
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index eebbe5a84b2b..9188985694f0 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -137,7 +137,7 @@ struct exfat_dentry_namebuf {
struct exfat_uni_name {
/* +3 for null and for converting */
unsigned short name[MAX_NAME_LENGTH + 3];
- unsigned short name_hash;
+ u16 name_hash;
unsigned char name_len;
};
@@ -512,8 +512,7 @@ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
void exfat_truncate_atime(struct timespec64 *ts);
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
-unsigned short exfat_calc_chksum_2byte(void *data, int len,
- unsigned short chksum, int type);
+u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync);
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c
index b82d2dd5bd7c..17d41f3d3709 100644
--- a/fs/exfat/misc.c
+++ b/fs/exfat/misc.c
@@ -136,17 +136,15 @@ void exfat_truncate_atime(struct timespec64 *ts)
ts->tv_nsec = 0;
}
-unsigned short exfat_calc_chksum_2byte(void *data, int len,
- unsigned short chksum, int type)
+u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type)
{
int i;
- unsigned char *c = (unsigned char *)data;
+ u8 *c = (u8 *)data;
for (i = 0; i < len; i++, c++) {
- if (((i == 2) || (i == 3)) && (type == CS_DIR_ENTRY))
+ if (unlikely(type == CS_DIR_ENTRY && (i == 2 || i == 3)))
continue;
- chksum = (((chksum & 1) << 15) | ((chksum & 0xFFFE) >> 1)) +
- (unsigned short)*c;
+ chksum = ((chksum << 15) | (chksum >> 1)) + *c;
}
return chksum;
}
diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c
index 1ebda90cbdd7..19321773dd07 100644
--- a/fs/exfat/nls.c
+++ b/fs/exfat/nls.c
@@ -527,7 +527,7 @@ static int exfat_utf8_to_utf16(struct super_block *sb,
*uniname = '\0';
p_uniname->name_len = unilen;
- p_uniname->name_hash = exfat_calc_chksum_2byte(upname, unilen << 1, 0,
+ p_uniname->name_hash = exfat_calc_chksum16(upname, unilen << 1, 0,
CS_DEFAULT);
if (p_lossy)
@@ -623,7 +623,7 @@ static int exfat_nls_to_ucs2(struct super_block *sb,
*uniname = '\0';
p_uniname->name_len = unilen;
- p_uniname->name_hash = exfat_calc_chksum_2byte(upname, unilen << 1, 0,
+ p_uniname->name_hash = exfat_calc_chksum16(upname, unilen << 1, 0,
CS_DEFAULT);
if (p_lossy)
@@ -655,7 +655,8 @@ static int exfat_load_upcase_table(struct super_block *sb,
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
unsigned int sect_size = sb->s_blocksize;
- unsigned int i, index = 0, checksum = 0;
+ unsigned int i, index = 0;
+ u32 chksum = 0;
int ret;
unsigned char skip = false;
unsigned short *upcase_table;
@@ -681,13 +682,6 @@ static int exfat_load_upcase_table(struct super_block *sb,
for (i = 0; i < sect_size && index <= 0xFFFF; i += 2) {
unsigned short uni = get_unaligned_le16(bh->b_data + i);
- checksum = ((checksum & 1) ? 0x80000000 : 0) +
- (checksum >> 1) +
- *(((unsigned char *)bh->b_data) + i);
- checksum = ((checksum & 1) ? 0x80000000 : 0) +
- (checksum >> 1) +
- *(((unsigned char *)bh->b_data) + (i + 1));
-
if (skip) {
index += uni;
skip = false;
@@ -701,13 +695,14 @@ static int exfat_load_upcase_table(struct super_block *sb,
}
}
brelse(bh);
+ chksum = exfat_calc_chksum32(bh->b_data, i, chksum, CS_DEFAULT);
}
- if (index >= 0xFFFF && utbl_checksum == checksum)
+ if (index >= 0xFFFF && utbl_checksum == chksum)
return 0;
exfat_err(sb, "failed to load upcase table (idx : 0x%08x, chksum : 0x%08x, utbl_chksum : 0x%08x)",
- index, checksum, utbl_checksum);
+ index, chksum, utbl_checksum);
ret = -EINVAL;
free_table:
exfat_free_upcase_table(sbi);
--
2.25.1