The patch titled
Avoid disk sector_t overflow for >2TB ext3 filesystem
has been added to the -mm tree. Its filename is
avoid-disk-sector_t-overflow-for-2tb-ext3-filesystem.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Avoid disk sector_t overflow for >2TB ext3 filesystem
From: Mingming Cao <cmm@xxxxxxxxxx>
If ext3 filesystem is larger than 2TB, and sector_t is a u32 (i.e.
CONFIG_LBD not defined in the kernel), the calculation of the disk sector
will overflow. Add check at ext3_fill_super() and ext3_group_extend() to
prevent mount/remount/resize >2TB ext3 filesystem if sector_t size is 4
bytes.
Verified this patch on a 32 bit platform without CONFIG_LBD defined
(sector_t is 32 bits long), mount refuse to mount a 10TB ext3.
Signed-off-by: Mingming Cao<cmm@xxxxxxxxxx>
Acked-by: Andreas Dilger <adilger@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/ext3/resize.c | 10 ++++++++++
fs/ext3/super.c | 10 ++++++++++
2 files changed, 20 insertions(+)
diff -puN fs/ext3/resize.c~avoid-disk-sector_t-overflow-for-2tb-ext3-filesystem fs/ext3/resize.c
--- devel/fs/ext3/resize.c~avoid-disk-sector_t-overflow-for-2tb-ext3-filesystem 2006-05-22 14:09:53.000000000 -0700
+++ devel-akpm/fs/ext3/resize.c 2006-05-22 14:10:56.000000000 -0700
@@ -926,6 +926,16 @@ int ext3_group_extend(struct super_block
if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
return 0;
+ if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
+ printk(KERN_ERR "EXT3-fs: filesystem on %s:"
+ " too large to resize to %lu blocks safely\n",
+ sb->s_id, n_blocks_count);
+ if (sizeof(sector_t) < 8)
+ ext3_warning(sb, __FUNCTION__,
+ "CONFIG_LBD not enabled\n");
+ return -EINVAL;
+ }
+
if (n_blocks_count < o_blocks_count) {
ext3_warning(sb, __FUNCTION__,
"can't shrink FS - resize aborted");
diff -puN fs/ext3/super.c~avoid-disk-sector_t-overflow-for-2tb-ext3-filesystem fs/ext3/super.c
--- devel/fs/ext3/super.c~avoid-disk-sector_t-overflow-for-2tb-ext3-filesystem 2006-05-22 14:09:53.000000000 -0700
+++ devel-akpm/fs/ext3/super.c 2006-05-22 14:11:10.000000000 -0700
@@ -1565,6 +1565,16 @@ static int ext3_fill_super (struct super
goto failed_mount;
}
+ if (le32_to_cpu(es->s_blocks_count) >
+ (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
+ printk(KERN_ERR "EXT3-fs: filesystem on %s:"
+ " too large to mount safely\n", sb->s_id);
+ if (sizeof(sector_t) < 8)
+ printk(KERN_WARNING "EXT3-fs: CONFIG_LBD not "
+ "enabled\n");
+ goto failed_mount;
+ }
+
if (EXT3_BLOCKS_PER_GROUP(sb) == 0)
goto cantfind_ext3;
sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
_
Patches currently in -mm which might be from cmm@xxxxxxxxxx are
percpu-counter-data-type-changes-to-suppport.patch
avoid-disk-sector_t-overflow-for-2tb-ext3-filesystem.patch
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