The patch titled
tmpfs: fix mounts when size is less than the page size
has been added to the -mm tree. Its filename is
tmpfs-fix-mounts-when-size-is-less-than-the-page-size.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: tmpfs: fix mounts when size is less than the page size
From: Michael Marineau <mike@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/shmem.c~tmpfs-fix-mounts-when-size-is-less-than-the-page-size mm/shmem.c
--- a/mm/shmem.c~tmpfs-fix-mounts-when-size-is-less-than-the-page-size
+++ a/mm/shmem.c
@@ -2012,7 +2012,7 @@ 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)
_
Patches currently in -mm which might be from mike@xxxxxxxxxxxx are
tmpfs-fix-mounts-when-size-is-less-than-the-page-size.patch
-
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