> 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 <kohada...@gmail.com>

Reviewed-by: Sungjong Seo <sj1557....@samsung.com>

> ---
> Changes in v2:
>  - rebase with patch 'optimize dir-cache' applied Changes in v3:
>  - rename BOOTSEC_OEM_NAME_LEN to BOOTSEC_FS_NAME_LEN
>  - rename oem_name to fs_name in struct boot_sector
> 
>  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..07f74190df44 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_FS_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    fs_name[BOOTSEC_FS_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


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