I figure before we get too fired up about 48 bits and ext4 let's fix 32 bits on ext3 :)
I need to do some actual IO testing now, but this gets things mounting for a 16T ext3 filesystem.
(patched up e2fsprogs is needed too, I'll send that off the kernel list)
This patch fixes these issues in the kernel:
o sbi->s_groups_count overflows in ext3_fill_super()
sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
le32_to_cpu(es->s_first_data_block) +
EXT3_BLOCKS_PER_GROUP(sb) - 1) /
EXT3_BLOCKS_PER_GROUP(sb);
at 16T, s_blocks_count is already maxed out; adding EXT3_BLOCKS_PER_GROUP(sb) overflows it and
groups_count comes out to 0. Not really what we want, and causes a failed mount.
Feel free to check my math (actually, please do!), but changing it this way should work &
avoid the overflow:
(A + B - 1)/B changed to: ((A - 1)/B) + 1
o ext3_check_descriptors() overflows range checks
ext3_check_descriptors() iterates over all block groups making sure that various bits are
within the right block ranges... on the last pass through, it is checking the error case
[item] >= block + EXT3_BLOCKS_PER_GROUP(sb)
where "block" is the first block in the last block group. The last block in this group
(and the last one that will fit in 32 bits) is block + EXT3_BLOCKS_PER_GROUP(sb)- 1.
block + EXT3_BLOCKS_PER_GROUP(sb) wraps back around to 0.
so, make things clearer with "first_block" and "last_block" where those are first and last,
inclusive, and use <, > rather than <, >=.
Finally, the last block group may be smaller than the rest, so account for this on the last
pass through: last_block = sb->s_blocks_count - 1;
(a similar patch could be done for ext2; does anyone in their right mind use ext2 at 16T?
I'll send an ext2 patch doing the same thing if that's warranted)
Thanks,
-Eric
Signed-off-by: Eric Sandeen <[email protected]>
Index: linux-2.6-xfs/fs/ext3/super.c
===================================================================
--- linux-2.6-xfs.orig/fs/ext3/super.c
+++ linux-2.6-xfs/fs/ext3/super.c
@@ -1132,7 +1132,8 @@ static int ext3_setup_super(struct super
static int ext3_check_descriptors (struct super_block * sb)
{
struct ext3_sb_info *sbi = EXT3_SB(sb);
- ext3_fsblk_t block = le32_to_cpu(sbi->s_es->s_first_data_block);
+ ext3_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+ ext3_fsblk_t last_block;
struct ext3_group_desc * gdp = NULL;
int desc_block = 0;
int i;
@@ -1141,12 +1142,16 @@ static int ext3_check_descriptors (struc
for (i = 0; i < sbi->s_groups_count; i++)
{
+ if (i == sbi->s_groups_count - 1)
+ last_block = sb->s_blocks_count - 1;
+ else
+ last = first + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
+
if ((i % EXT3_DESC_PER_BLOCK(sb)) == 0)
gdp = (struct ext3_group_desc *)
sbi->s_group_desc[desc_block++]->b_data;
- if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
- le32_to_cpu(gdp->bg_block_bitmap) >=
- block + EXT3_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_block_bitmap) > last_block)
{
ext3_error (sb, "ext3_check_descriptors",
"Block bitmap for group %d"
@@ -1155,9 +1160,8 @@ static int ext3_check_descriptors (struc
le32_to_cpu(gdp->bg_block_bitmap));
return 0;
}
- if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
- le32_to_cpu(gdp->bg_inode_bitmap) >=
- block + EXT3_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
{
ext3_error (sb, "ext3_check_descriptors",
"Inode bitmap for group %d"
@@ -1166,9 +1170,9 @@ static int ext3_check_descriptors (struc
le32_to_cpu(gdp->bg_inode_bitmap));
return 0;
}
- if (le32_to_cpu(gdp->bg_inode_table) < block ||
- le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
- block + EXT3_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+ le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
+ last_block)
{
ext3_error (sb, "ext3_check_descriptors",
"Inode table for group %d"
@@ -1177,7 +1181,7 @@ static int ext3_check_descriptors (struc
le32_to_cpu(gdp->bg_inode_table));
return 0;
}
- block += EXT3_BLOCKS_PER_GROUP(sb);
+ first_block += EXT3_BLOCKS_PER_GROUP(sb);
gdp++;
}
@@ -1580,10 +1584,9 @@ static int ext3_fill_super (struct super
if (EXT3_BLOCKS_PER_GROUP(sb) == 0)
goto cantfind_ext3;
- sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
- le32_to_cpu(es->s_first_data_block) +
- EXT3_BLOCKS_PER_GROUP(sb) - 1) /
- EXT3_BLOCKS_PER_GROUP(sb);
+ sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+ le32_to_cpu(es->s_first_data_block) - 1)
+ / EXT3_BLOCKS_PER_GROUP(sb)) + 1;
db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
EXT3_DESC_PER_BLOCK(sb);
sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
On Fri, 2006-08-11 at 17:13 -0500, Eric Sandeen wrote:
> I figure before we get too fired up about 48 bits and ext4 let's fix 32 bits on ext3 :)
>
> I need to do some actual IO testing now, but this gets things mounting for a 16T ext3 filesystem.
> (patched up e2fsprogs is needed too, I'll send that off the kernel list)
>
> This patch fixes these issues in the kernel:
>
> o sbi->s_groups_count overflows in ext3_fill_super()
>
> sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
> le32_to_cpu(es->s_first_data_block) +
> EXT3_BLOCKS_PER_GROUP(sb) - 1) /
> EXT3_BLOCKS_PER_GROUP(sb);
>
> at 16T, s_blocks_count is already maxed out; adding EXT3_BLOCKS_PER_GROUP(sb) overflows it and
> groups_count comes out to 0. Not really what we want, and causes a failed mount.
>
> Feel free to check my math (actually, please do!), but changing it this way should work &
> avoid the overflow:
>
> (A + B - 1)/B changed to: ((A - 1)/B) + 1
>
> o ext3_check_descriptors() overflows range checks
Looks correct to me.:)
Mingming
Eric Sandeen wrote:
> I figure before we get too fired up about 48 bits and ext4 let's fix 32 bits on ext3 :)
>
Urk... must remember to "quilt refresh..." - this version actually compiles :/ sorry!
(1st part of 2nd hunk was wrong before)
Signed-off-by: Eric Sandeen <[email protected]>
Index: linux-2.6.17/fs/ext3/super.c
===================================================================
--- linux-2.6.17.orig/fs/ext3/super.c
+++ linux-2.6.17/fs/ext3/super.c
@@ -1132,7 +1132,8 @@ static int ext3_setup_super(struct super
static int ext3_check_descriptors (struct super_block * sb)
{
struct ext3_sb_info *sbi = EXT3_SB(sb);
- ext3_fsblk_t block = le32_to_cpu(sbi->s_es->s_first_data_block);
+ ext3_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+ ext3_fsblk_t last_block;
struct ext3_group_desc * gdp = NULL;
int desc_block = 0;
int i;
@@ -1141,12 +1142,17 @@ static int ext3_check_descriptors (struc
for (i = 0; i < sbi->s_groups_count; i++)
{
+ if (i == sbi->s_groups_count - 1)
+ last_block = sbi->s_es->s_blocks_count - 1;
+ else
+ last_block = first_block +
+ (EXT3_BLOCKS_PER_GROUP(sb) - 1);
+
if ((i % EXT3_DESC_PER_BLOCK(sb)) == 0)
gdp = (struct ext3_group_desc *)
sbi->s_group_desc[desc_block++]->b_data;
- if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
- le32_to_cpu(gdp->bg_block_bitmap) >=
- block + EXT3_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_block_bitmap) > last_block)
{
ext3_error (sb, "ext3_check_descriptors",
"Block bitmap for group %d"
@@ -1155,9 +1161,8 @@ static int ext3_check_descriptors (struc
le32_to_cpu(gdp->bg_block_bitmap));
return 0;
}
- if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
- le32_to_cpu(gdp->bg_inode_bitmap) >=
- block + EXT3_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
{
ext3_error (sb, "ext3_check_descriptors",
"Inode bitmap for group %d"
@@ -1166,9 +1171,9 @@ static int ext3_check_descriptors (struc
le32_to_cpu(gdp->bg_inode_bitmap));
return 0;
}
- if (le32_to_cpu(gdp->bg_inode_table) < block ||
- le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
- block + EXT3_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+ le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
+ last_block)
{
ext3_error (sb, "ext3_check_descriptors",
"Inode table for group %d"
@@ -1177,7 +1182,7 @@ static int ext3_check_descriptors (struc
le32_to_cpu(gdp->bg_inode_table));
return 0;
}
- block += EXT3_BLOCKS_PER_GROUP(sb);
+ first_block += EXT3_BLOCKS_PER_GROUP(sb);
gdp++;
}
@@ -1580,10 +1585,9 @@ static int ext3_fill_super (struct super
if (EXT3_BLOCKS_PER_GROUP(sb) == 0)
goto cantfind_ext3;
- sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
- le32_to_cpu(es->s_first_data_block) +
- EXT3_BLOCKS_PER_GROUP(sb) - 1) /
- EXT3_BLOCKS_PER_GROUP(sb);
+ sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+ le32_to_cpu(es->s_first_data_block) - 1)
+ / EXT3_BLOCKS_PER_GROUP(sb)) + 1;
db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
EXT3_DESC_PER_BLOCK(sb);
sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
On Fri, 11 Aug 2006 17:13:14 -0500
Eric Sandeen <[email protected]> wrote:
> (a similar patch could be done for ext2; does anyone in their right mind use ext2 at 16T?
well, a bug's a bug. People might want to ue 16TB ext2 for comparative
performance testing, or because they get their jollies from running fsck or
something.
> I'll send an ext2 patch doing the same thing if that's warranted)
please, when you have nothing better to do ;)
Andrew Morton wrote:
> On Fri, 11 Aug 2006 17:13:14 -0500
> Eric Sandeen <[email protected]> wrote:
>
>> (a similar patch could be done for ext2; does anyone in their right mind use ext2 at 16T?
>
> well, a bug's a bug. People might want to ue 16TB ext2 for comparative
> performance testing, or because they get their jollies from running fsck or
> something.
ext2 and ext3 have seemingly already diverged a bit, but I suppose no reason to
let it go further.
>> I'll send an ext2 patch doing the same thing if that's warranted)
>
> please, when you have nothing better to do ;)
Will do :)
-Eric
Andrew Morton wrote:
>> (I'll send an ext2 patch doing the same thing if that's warranted)
> please, when you have nothing better to do ;)
Ok, here's the ext2 version. note however that ext2 never got the ext3_fsblk_t
treatment, so there are probably signed containers lurking in ext2 still. I'll leave
that for another day when I have nothing better to do ;-) But at least this part
is less divergent now.
Signed-off-by: Eric Sandeen <[email protected]>
--- linux.orig/fs/ext2/super.c
+++ linux/fs/ext2/super.c
@@ -505,17 +505,24 @@ static int ext2_check_descriptors (struc
int i;
int desc_block = 0;
struct ext2_sb_info *sbi = EXT2_SB(sb);
- unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
+ unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+ unsigned long last_block;
struct ext2_group_desc * gdp = NULL;
ext2_debug ("Checking group descriptors");
for (i = 0; i < sbi->s_groups_count; i++)
{
+ if (i == sbi->s_groups_count - 1)
+ last_block = sbi->s_es->s_blocks_count - 1;
+ else
+ last_block = first_block +
+ (EXT2_BLOCKS_PER_GROUP(sb) - 1);
+
if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
- if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
- le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_block_bitmap) > last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Block bitmap for group %d"
@@ -523,8 +530,8 @@ static int ext2_check_descriptors (struc
i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
return 0;
}
- if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
- le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+ le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Inode bitmap for group %d"
@@ -532,9 +539,9 @@ static int ext2_check_descriptors (struc
i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
return 0;
}
- if (le32_to_cpu(gdp->bg_inode_table) < block ||
- le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
- block + EXT2_BLOCKS_PER_GROUP(sb))
+ if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+ le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
+ last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Inode table for group %d"
@@ -542,7 +549,7 @@ static int ext2_check_descriptors (struc
i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
return 0;
}
- block += EXT2_BLOCKS_PER_GROUP(sb);
+ first_block += EXT2_BLOCKS_PER_GROUP(sb);
gdp++;
}
return 1;
@@ -822,10 +829,9 @@ static int ext2_fill_super(struct super_
if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
goto cantfind_ext2;
- sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
- le32_to_cpu(es->s_first_data_block) +
- EXT2_BLOCKS_PER_GROUP(sb) - 1) /
- EXT2_BLOCKS_PER_GROUP(sb);
+ sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+ le32_to_cpu(es->s_first_data_block) - 1)
+ / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
EXT2_DESC_PER_BLOCK(sb);
sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
> static int ext3_check_descriptors (struct super_block * sb)
> {
> struct ext3_sb_info *sbi = EXT3_SB(sb);
> - ext3_fsblk_t block = le32_to_cpu(sbi->s_es->s_first_data_block);
> + ext3_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
> + ext3_fsblk_t last_block;
> struct ext3_group_desc * gdp = NULL;
> int desc_block = 0;
> int i;
> @@ -1141,12 +1142,16 @@ static int ext3_check_descriptors (struc
>
> for (i = 0; i < sbi->s_groups_count; i++)
> {
> + if (i == sbi->s_groups_count - 1)
> + last_block = sb->s_blocks_count - 1;
> + else
> + last = first + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
I think it should be:
last_block = first_block + ...
Johann
On Aug 11, 2006 15:29 -0700, Mingming Cao wrote:
> On Fri, 2006-08-11 at 17:13 -0500, Eric Sandeen wrote:
> > I figure before we get too fired up about 48 bits and ext4 let's fix 32 bits on ext3 :)
> >
> > I need to do some actual IO testing now, but this gets things mounting for a 16T ext3 filesystem.
> > (patched up e2fsprogs is needed too, I'll send that off the kernel list)
> >
> > This patch fixes these issues in the kernel:
> >
> > o sbi->s_groups_count overflows in ext3_fill_super()
> >
> > sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
> > le32_to_cpu(es->s_first_data_block) +
> > EXT3_BLOCKS_PER_GROUP(sb) - 1) /
> > EXT3_BLOCKS_PER_GROUP(sb);
> >
> > at 16T, s_blocks_count is already maxed out; adding EXT3_BLOCKS_PER_GROUP(sb) overflows it and
> > groups_count comes out to 0. Not really what we want, and causes a failed mount.
> >
> > Feel free to check my math (actually, please do!), but changing it this way should work &
> > avoid the overflow:
> >
> > (A + B - 1)/B changed to: ((A - 1)/B) + 1
> >
> > o ext3_check_descriptors() overflows range checks
This is generally not safe because of underflow, but it also isn't possible
to have a 0-block filesystem so it should be OK.
Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.