Messages in this thread Patch in this message | | | Date | Sun, 4 Nov 2007 12:19:26 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: [PATCH, RESEND] tmpfs: fix mounts when size is less than the page size |
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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?
From: Michael Marineau <mike@marineau.org>
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 <mike@marineau.org> Signed-off-by: Hugh Dickins <hugh@veritas.com> ---
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) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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