[PATCH 2/2] hfsplus: fix filesystem size checks

[Christoph Hellwig <hch@infradead.org>]

From: Christoph Hellwig <hch@tuxera.com>

generic_check_addressable can't deal with hfsplus's larger than page size
allocation blocks, so simply opencode the checks that we actually need
in hfsplus_fill_super.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Reported-by: Pavel Ivanov <paivanof@gmail.com>
Tested-by: Pavel Ivanov <paivanof@gmail.com>

Index: linux-2.6/fs/hfsplus/super.c
===================================================================
--- linux-2.6.orig/fs/hfsplus/super.c	2011-09-15 10:26:10.059350285 -0400
+++ linux-2.6/fs/hfsplus/super.c	2011-09-15 10:26:24.960348414 -0400
@@ -344,6 +344,7 @@ static int hfsplus_fill_super(struct sup
 	struct inode *root, *inode;
 	struct qstr str;
 	struct nls_table *nls = NULL;
+	u64 last_fs_block, last_fs_page;
 	int err;
 
 	err = -EINVAL;
@@ -399,9 +400,13 @@ static int hfsplus_fill_super(struct sup
 	if (!sbi->rsrc_clump_blocks)
 		sbi->rsrc_clump_blocks = 1;
 
-	err = generic_check_addressable(sbi->alloc_blksz_shift,
-					sbi->total_blocks);
-	if (err) {
+	err = -EFBIG;
+	last_fs_block = sbi->total_blocks - 1;
+	last_fs_page = (last_fs_block << sbi->alloc_blksz_shift) >>
+			PAGE_CACHE_SHIFT;
+
+	if ((last_fs_block > (sector_t)(~0ULL) >> (sbi->alloc_blksz_shift - 9)) ||
+	    (last_fs_page > (pgoff_t)(~0ULL))) {
 		printk(KERN_ERR "hfs: filesystem size too large.\n");
 		goto out_free_vhdr;
 	}