2007-07-24 11:04:24

by Girish Shilamkar

Subject: [Patch 7/13] Many inodes in filesystem.

Handle filesystems with many hard links that have more than ~700M inodes.
The float variable lacks precision at this scale.

Signed-off-by: Andreas Dilger <[email protected]>
Signed-off-by: Girish Shilamkar <[email protected]>
Signed-off-by: Kalpak Shah <[email protected]>

Index: e2fsprogs-1.40.1/lib/ext2fs/icount.c
===================================================================
--- e2fsprogs-1.40.1.orig/lib/ext2fs/icount.c
+++ e2fsprogs-1.40.1/lib/ext2fs/icount.c
@@ -376,6 +376,10 @@ static struct ext2_icount_el *get_icount
range = 0.1;
}
mid = low + ((int) (range * (high-low)));
+ if (mid > high)
+ mid = high;
+ if (mid < low)
+ mid = low;
}
#endif
if (ino == icount->list[mid].ino) {

2007-07-24 14:35:35

by Theodore Ts'o

Subject: Re: [Patch 7/13] Many inodes in filesystem.

On Tue, Jul 24, 2007 at 04:34:59PM +0530, Girish Shilamkar wrote:
> Handle filesystems with many hard links that have more than ~700M inodes.
> The float variable lacks precision at this scale.

This was fixed in e2fsprogs mainline a slightly different way. Just
above it:

range = ((float) (ino - lowval)) /
(highval - lowval);
if (range > 0.9)
range = 0.9;
if (range < 0.1)
range = 0.1;

The problem with just correcting the midpoint calculation as you
proposed in your patch is that you could end up doing a linear search
through the whole array in some really abberrant cases. With this fix
applied in e2fsprogs, the patch below isn't required.

Regards,

- Ted

> Signed-off-by: Andreas Dilger <[email protected]>
> Signed-off-by: Girish Shilamkar <[email protected]>
> Signed-off-by: Kalpak Shah <[email protected]>
>
> Index: e2fsprogs-1.40.1/lib/ext2fs/icount.c
> ===================================================================
> --- e2fsprogs-1.40.1.orig/lib/ext2fs/icount.c
> +++ e2fsprogs-1.40.1/lib/ext2fs/icount.c
> @@ -376,6 +376,10 @@ static struct ext2_icount_el *get_icount
> range = 0.1;
> }
> mid = low + ((int) (range * (high-low)));
> + if (mid > high)
> + mid = high;
> + if (mid < low)
> + mid = low;
> }
> #endif
> if (ino == icount->list[mid].ino) {
>
>