Messages in this thread Patch in this message |  | | From | David Howells <> | Subject | [PATCH] ramfs: fix memleak on no-mmu arch | Date | Wed, 13 Apr 2011 17:45:21 +0100 |
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From: Bob Liu <lliubbo@gmail.com>
On no-mmu arch, there is a memleak duirng shmem test. The cause of this memleak is ramfs_nommu_expand_for_mapping() added page refcount to 2 which makes iput() can't free that pages.
The simple test file is like this: int main(void) { int i; key_t k = ftok("/etc", 42);
for ( i=0; i<100; ++i) { int id = shmget(k, 10000, 0644|IPC_CREAT); if (id == -1) { printf("shmget error\n"); } if(shmctl(id, IPC_RMID, NULL ) == -1) { printf("shm rm error\n"); return -1; } } printf("run ok...\n"); return 0; }
And the result: root:/> free total used free shared buffers Mem: 60320 16644 43676 0 0 -/+ buffers: 16644 43676 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 17912 42408 0 0 -/+ buffers: 17912 42408 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 19096 41224 0 0 -/+ buffers: 19096 41224 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 20296 40024 0 0 -/+ buffers: 20296 40024 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 21496 38824 0 0 -/+ buffers: 21496 38824 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 22692 37628 0 0 -/+ buffers: 22692 37628 root:/>
After this patch the test result is:(no memleak anymore) root:/> root:/> free total used free shared buffers Mem: 60320 16580 43740 0 0 -/+ buffers: 16580 43740 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/> shmem run ok... root:/> free total used free shared buffers Mem: 60320 16668 43652 0 0 -/+ buffers: 16668 43652 root:/>
Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: David Howells <dhowells@redhat.com> ---
fs/ramfs/file-nommu.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 9eead2c..fbb0b47 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -112,6 +112,7 @@ int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize) SetPageDirty(page); unlock_page(page); + put_page(page); } return 0;
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