From: Yasunori Goto <y-goto@jp.fujitsu.com>
Date: Tue, 17 Feb 2009 15:58:25 +0000 (-0500)
Subject: ext4: Widen type of ext4_sb_info.s_mb_maxs[]
X-Git-Tag: v2.6.27.19~20
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=16cde8908e8b7145d61a5e0e25505966df66d7ee;p=thirdparty%2Fkernel%2Fstable.git

ext4: Widen type of ext4_sb_info.s_mb_maxs[]

(cherry picked from commit ff7ef329b268b603ea4a2303241ef1c3829fd574)

I chased the cause of following ext4 oops report which is tested on
ia64 box.

http://bugzilla.kernel.org/show_bug.cgi?id=12018

The cause is the size of s_mb_maxs array that is defined as "unsigned
short" in ext4_sb_info structure.  If the file system's block size is
8k or greater, an unsigned short is not wide enough to contain the
value fs->blocksize << 3.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/fs/ext4/ext4_sb.h b/fs/ext4/ext4_sb.h
index 0881b2c06b770..f20df8adfe18d 100644
--- a/fs/ext4/ext4_sb.h
+++ b/fs/ext4/ext4_sb.h
@@ -103,7 +103,8 @@ struct ext4_sb_info {
 	struct list_head s_committed_transaction;
 	spinlock_t s_md_lock;
 	tid_t s_last_transaction;
-	unsigned short *s_mb_offsets, *s_mb_maxs;
+	unsigned short *s_mb_offsets;
+	unsigned int *s_mb_maxs;
 
 	/* tunables */
 	unsigned long s_stripe;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index ba86b563381a4..c30048fc5dffd 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2495,6 +2495,8 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 		clear_opt(sbi->s_mount_opt, MBALLOC);
 		return -ENOMEM;
 	}
+
+	i = (sb->s_blocksize_bits + 2) * sizeof(unsigned int);
 	sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
 	if (sbi->s_mb_maxs == NULL) {
 		clear_opt(sbi->s_mount_opt, MBALLOC);