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 2f3b8b1ca59263aa61c5bee85bb6c4e351516bee..f00f112edea1e49ef37ebc9bd8e0526374e60ef2 100644 (file)
--- a/fs/ext4/ext4_sb.h
+++ b/fs/ext4/ext4_sb.h
@@ -102,7 +102,8 @@ struct ext4_sb_info {
        spinlock_t s_reserve_lock;
        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 444ad998f72e77ab663730c6f59e43a7b9ac1e57..7beab7141dd5872f78bd8b965e0e24345bfd6831 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2493,6 +2493,8 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
        if (sbi->s_mb_offsets == NULL) {
                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) {
                kfree(sbi->s_mb_maxs);