1 files changed, 146 insertions, 72 deletions

diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c
index 8972c20b321..cc623567143 100644
--- a/fs/hfsplus/wrapper.c
+++ b/fs/hfsplus/wrapper.c
@@ -24,6 +24,71 @@ struct hfsplus_wd {
 	u16 embed_count;
 };
 
+/**
+ * hfsplus_submit_bio - Perform block I/O
+ * @sb: super block of volume for I/O
+ * @sector: block to read or write, for blocks of HFSPLUS_SECTOR_SIZE bytes
+ * @buf: buffer for I/O
+ * @data: output pointer for location of requested data
+ * @rw: direction of I/O
+ *
+ * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than
+ * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads
+ * @data will return a pointer to the start of the requested sector,
+ * which may not be the same location as @buf.
+ *
+ * If @sector is not aligned to the bdev logical block size it will
+ * be rounded down. For writes this means that @buf should contain data
+ * that starts at the rounded-down address. As long as the data was
+ * read using hfsplus_submit_bio() and the same buffer is used things
+ * will work correctly.
+ */
+int hfsplus_submit_bio(struct super_block *sb, sector_t sector,
+		void *buf, void **data, int rw)
+{
+	struct bio *bio;
+	int ret = 0;
+	u64 io_size;
+	loff_t start;
+	int offset;
+
+	/*
+	 * Align sector to hardware sector size and find offset. We
+	 * assume that io_size is a power of two, which _should_
+	 * be true.
+	 */
+	io_size = hfsplus_min_io_size(sb);
+	start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT;
+	offset = start & (io_size - 1);
+	sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1);
+
+	bio = bio_alloc(GFP_NOIO, 1);
+	bio->bi_iter.bi_sector = sector;
+	bio->bi_bdev = sb->s_bdev;
+
+	if (!(rw & WRITE) && data)
+		*data = (u8 *)buf + offset;
+
+	while (io_size > 0) {
+		unsigned int page_offset = offset_in_page(buf);
+		unsigned int len = min_t(unsigned int, PAGE_SIZE - page_offset,
+					 io_size);
+
+		ret = bio_add_page(bio, virt_to_page(buf), len, page_offset);
+		if (ret != len) {
+			ret = -EIO;
+			goto out;
+		}
+		io_size -= len;
+		buf = (u8 *)buf + len;
+	}
+
+	ret = submit_bio_wait(rw, bio);
+out:
+	bio_put(bio);
+	return ret < 0 ? ret : 0;
+}
+
 static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
 {
 	u32 extent;
@@ -40,12 +105,14 @@ static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
 	   !(attrib & HFSP_WRAP_ATTRIB_SPARED))
 		return 0;
 
-	wd->ablk_size = be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
+	wd->ablk_size =
+		be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
 	if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
 		return 0;
 	if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
 		return 0;
-	wd->ablk_start = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
+	wd->ablk_start =
+		be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
 
 	extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
 	wd->embed_start = (extent >> 16) & 0xFFFF;
@@ -68,16 +135,18 @@ static int hfsplus_get_last_session(struct super_block *sb,
 	if (HFSPLUS_SB(sb)->session >= 0) {
 		te.cdte_track = HFSPLUS_SB(sb)->session;
 		te.cdte_format = CDROM_LBA;
-		res = ioctl_by_bdev(sb->s_bdev, CDROMREADTOCENTRY, (unsigned long)&te);
+		res = ioctl_by_bdev(sb->s_bdev,
+			CDROMREADTOCENTRY, (unsigned long)&te);
 		if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
 			*start = (sector_t)te.cdte_addr.lba << 2;
 			return 0;
 		}
-		printk(KERN_ERR "hfs: invalid session number or type of track\n");
+		pr_err("invalid session number or type of track\n");
 		return -EINVAL;
 	}
 	ms_info.addr_format = CDROM_LBA;
-	res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, (unsigned long)&ms_info);
+	res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION,
+		(unsigned long)&ms_info);
 	if (!res && ms_info.xa_flag)
 		*start = (sector_t)ms_info.addr.lba << 2;
 	return 0;
@@ -88,100 +157,105 @@ 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;
-	if ((u64)part_start + part_size > 0x100000000ULL) {
-		pr_err("hfs: volumes larger than 2TB are not supported yet\n");
-		return -EINVAL;
-	}
-	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);
+		goto out;
+
+	error = -ENOMEM;
+	sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+	if (!sbi->s_vhdr_buf)
+		goto out;
+	sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+	if (!sbi->s_backup_vhdr_buf)
+		goto out_free_vhdr;
 
-		/* check for a partition block
+reread:
+	error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR,
+				   sbi->s_vhdr_buf, (void **)&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_free_backup_vhdr;
+		wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
+		part_start += (sector_t)wd.ablk_start +
+			       (sector_t)wd.embed_start * wd.ablk_size;
+		part_size = (sector_t)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_free_backup_vhdr;
+		goto reread;
+	}
+
+	error = hfsplus_submit_bio(sb, part_start + part_size - 2,
+				   sbi->s_backup_vhdr_buf,
+				   (void **)&sbi->s_backup_vhdr, READ);
+	if (error)
+		goto out_free_backup_vhdr;
+
+	error = -EINVAL;
+	if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
+		pr_warn("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);
+	sbi->alloc_blksz_shift = ilog2(blocksize);
+	blocksize = min_t(u32, sbi->alloc_blksz, 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;
+		pr_err("unable to set blocksize to %u!\n", blocksize);
+		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_buf);
+out_free_vhdr:
+	kfree(sbi->s_vhdr_buf);
+out:
+	return error;
 }