[patch 19/39] ext4: Widen type of ext4_sb_info.s_mb_maxs[]

[Greg KH]

2.6.28-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>

(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@xxxxxxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Miao Xie <miaox@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 fs/ext4/ext4_sb.h |    3 ++-
 fs/ext4/mballoc.c |    2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

--- 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;
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2493,6 +2493,8 @@ int ext4_mb_init(struct super_block *sb,
 	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);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/