On 11/4/07, Hugh Dickins <[EMAIL PROTECTED]> wrote:
> Fair enough, that does match the documentation of "size=0" better.
> Though either way, someone who typos is going to get one kind of surprise
> or another. Do you mind if we do it slightly differently, achieving the
> same effect without a special case, by rounding up instead of down?
Sounds reasonable to me. I didn't know about DIV_ROUND_UP :-)
>
>
> From: Michael Marineau <[EMAIL PROTECTED]>
>
> When tmpfs is mounted with a size less than one page, the number of blocks
> is set to 0 which makes the tmpfs mount unlimited. This can lead to a quick
> and surprising death if someone typos a tmpfs mount command and writes too
> much.
>
> tmpfs can still be mounted as unlimited if size or nr_blocks is exactly 0,
> as Documentation/filesystems/tmpfs.txt says.
>
> Hugh: do this by rounding size up instead of down in all cases: which
> slightly expands other odd-sized tmpfs mounts, but in a consistent way.
>
> Signed-off-by: Michael Marineau <[EMAIL PROTECTED]>
> Signed-off-by: Hugh Dickins <[EMAIL PROTECTED]>
> ---
>
> mm/shmem.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- 2.6.24-rc1-git/mm/shmem.c 2007-10-31 06:18:05.000000000 +0000
> +++ linux/mm/shmem.c 2007-11-04 11:46:09.000000000 +0000
> @@ -2137,7 +2137,7 @@ static int shmem_parse_options(char *opt
> }
> if (*rest)
> goto bad_val;
> - *blocks = size >> PAGE_CACHE_SHIFT;
> + *blocks = DIV_ROUND_UP(size, PAGE_CACHE_SIZE);
> } else if (!strcmp(this_char,"nr_blocks")) {
> *blocks = memparse(value,&rest);
> if (*rest)
>
--
Michael Marineau
Oregon State University
[EMAIL PROTECTED]
-
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