1 files changed, 104 insertions, 59 deletions

diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c
index 8972c20b3216..15e0eabb489e 100644
--- a/fs/hfsplus/wrapper.c
+++ b/fs/hfsplus/wrapper.c
@@ -24,6 +24,40 @@ struct hfsplus_wd {
         u16 embed_count;
 };
 
+static void hfsplus_end_io_sync(struct bio *bio, int err)
+{
+        if (err)
+                clear_bit(BIO_UPTODATE, &bio->bi_flags);
+        complete(bio->bi_private);
+}
+
+int hfsplus_submit_bio(struct block_device *bdev, sector_t sector,
+                void *data, int rw)
+{
+        DECLARE_COMPLETION_ONSTACK(wait);
+        struct bio *bio;
+
+        bio = bio_alloc(GFP_NOIO, 1);
+        bio->bi_sector = sector;
+        bio->bi_bdev = bdev;
+        bio->bi_end_io = hfsplus_end_io_sync;
+        bio->bi_private = &wait;
+
+        /*
+         * We always submit one sector at a time, so bio_add_page must not fail.
+         */
+        if (bio_add_page(bio, virt_to_page(data), HFSPLUS_SECTOR_SIZE,
+                         offset_in_page(data)) != HFSPLUS_SECTOR_SIZE)
+                BUG();
+
+        submit_bio(rw, bio);
+        wait_for_completion(&wait);
+
+        if (!bio_flagged(bio, BIO_UPTODATE))
+                return -EIO;
+        return 0;
+}
+
 static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
 {
         u32 extent;
@@ -88,100 +122,111 @@ static int hfsplus_get_last_session(struct super_block *sb,
 int hfsplus_read_wrapper(struct super_block *sb)
 {
         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
-        struct buffer_head *bh;
-        struct hfsplus_vh *vhdr;
         struct hfsplus_wd wd;
         sector_t part_start, part_size;
         u32 blocksize;
+        int error = 0;
 
+        error = -EINVAL;
         blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
         if (!blocksize)
-                return -EINVAL;
+                goto out;
 
         if (hfsplus_get_last_session(sb, &part_start, &part_size))
-                return -EINVAL;
+                goto out;
         if ((u64)part_start + part_size > 0x100000000ULL) {
                 pr_err("hfs: volumes larger than 2TB are not supported yet\n");
-                return -EINVAL;
+                goto out;
         }
-        while (1) {
-                bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr);
-                if (!bh)
-                        return -EIO;
-
-                if (vhdr->signature == cpu_to_be16(HFSP_WRAP_MAGIC)) {
-                        if (!hfsplus_read_mdb(vhdr, &wd))
-                                goto error;
-                        wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
-                        part_start += wd.ablk_start + wd.embed_start * wd.ablk_size;
-                        part_size = wd.embed_count * wd.ablk_size;
-                        brelse(bh);
-                        bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr);
-                        if (!bh)
-                                return -EIO;
-                }
-                if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIG))
-                        break;
-                if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) {
-                        set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
-                        break;
-                }
-                brelse(bh);
 
-                /* check for a partition block
+        error = -ENOMEM;
+        sbi->s_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
+        if (!sbi->s_vhdr)
+                goto out;
+        sbi->s_backup_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
+        if (!sbi->s_backup_vhdr)
+                goto out_free_vhdr;
+
+reread:
+        error = hfsplus_submit_bio(sb->s_bdev,
+                                   part_start + HFSPLUS_VOLHEAD_SECTOR,
+                                   sbi->s_vhdr, READ);
+        if (error)
+                goto out_free_backup_vhdr;
+
+        error = -EINVAL;
+        switch (sbi->s_vhdr->signature) {
+        case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
+                set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
+                /*FALLTHRU*/
+        case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
+                break;
+        case cpu_to_be16(HFSP_WRAP_MAGIC):
+                if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
+                        goto out;
+                wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
+                part_start += wd.ablk_start + wd.embed_start * wd.ablk_size;
+                part_size = wd.embed_count * wd.ablk_size;
+                goto reread;
+        default:
+                /*
+                 * Check for a partition block.
+                 *
                  * (should do this only for cdrom/loop though)
                  */
                 if (hfs_part_find(sb, &part_start, &part_size))
-                        return -EINVAL;
+                        goto out;
+                goto reread;
+        }
+
+        error = hfsplus_submit_bio(sb->s_bdev,
+                                   part_start + part_size - 2,
+                                   sbi->s_backup_vhdr, READ);
+        if (error)
+                goto out_free_backup_vhdr;
+
+        error = -EINVAL;
+        if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
+                printk(KERN_WARNING
+                        "hfs: invalid secondary volume header\n");
+                goto out_free_backup_vhdr;
         }
 
-        blocksize = be32_to_cpu(vhdr->blocksize);
-        brelse(bh);
+        blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
 
-        /* block size must be at least as large as a sector
-         * and a multiple of 2
+        /*
+         * Block size must be at least as large as a sector and a multiple of 2.
          */
-        if (blocksize < HFSPLUS_SECTOR_SIZE ||
-            ((blocksize - 1) & blocksize))
-                return -EINVAL;
+        if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
+                goto out_free_backup_vhdr;
         sbi->alloc_blksz = blocksize;
         sbi->alloc_blksz_shift = 0;
         while ((blocksize >>= 1) != 0)
                 sbi->alloc_blksz_shift++;
         blocksize = min(sbi->alloc_blksz, (u32)PAGE_SIZE);
 
-        /* align block size to block offset */
+        /*
+         * Align block size to block offset.
+         */
         while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
                 blocksize >>= 1;
 
         if (sb_set_blocksize(sb, blocksize) != blocksize) {
                 printk(KERN_ERR "hfs: unable to set blocksize to %u!\n", blocksize);
-                return -EINVAL;
+                goto out_free_backup_vhdr;
         }
 
         sbi->blockoffset =
                 part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
+        sbi->part_start = part_start;
         sbi->sect_count = part_size;
         sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
-
-        bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr);
-        if (!bh)
-                return -EIO;
-
-        /* should still be the same... */
-        if (test_bit(HFSPLUS_SB_HFSX, &sbi->flags)) {
-                if (vhdr->signature != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
-                        goto error;
-        } else {
-                if (vhdr->signature != cpu_to_be16(HFSPLUS_VOLHEAD_SIG))
-                        goto error;
-        }
-
-        sbi->s_vhbh = bh;
-        sbi->s_vhdr = vhdr;
-
         return 0;
- error:
-        brelse(bh);
-        return -EINVAL;
+
+out_free_backup_vhdr:
+        kfree(sbi->s_backup_vhdr);
+out_free_vhdr:
+        kfree(sbi->s_vhdr);
+out:
+        return error;
 }