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authorMichael Marineau <mike@marineau.org>2008-02-04 22:28:48 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:15 -0800
commit818db35992c249dc32c1d86daf7d533fb0952f5d (patch)
tree8577fe7cff367eade84f632621b16054c362d39a /mm/shmem.c
parent5b04c6890f0dc7ea6c85b9adebc883c55c667d97 (diff)
downloadop-kernel-dev-818db35992c249dc32c1d86daf7d533fb0952f5d.zip
op-kernel-dev-818db35992c249dc32c1d86daf7d533fb0952f5d.tar.gz
tmpfs: fix mounts when size is less than the page size
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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index ce64b66..7be9434 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2012,7 +2012,7 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid,
}
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)
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