exfat: redefine PBR as boot_sector

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.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index c84ae9e..911f58b 100644 (file)
--- 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 8d6c64a..07f7419 100644 (file)
--- 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 c1f47f4..e60d28e 100644 (file)
--- 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 @@ free_alloc_bitmap:
 free_upcase_table:
        exfat_free_upcase_table(sbi);
 free_bh:
-       brelse(sbi->pbr_bh);
+       brelse(sbi->boot_bh);
        return ret;
 }
 
@@ -608,7 +608,7 @@ put_inode:
 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);