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| author | Chuck Lever <chuck.lever@oracle.com> | 2011-01-21 16:54:57 +0100 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-01-25 21:24:47 +0100 |
| commit | 839f7ad6932d95f4d5ae7267b95c574714ff3d5b (patch) | |
| tree | 63dc2eec84a5ecb846145fd1dd70fe7cdd46fa7c /fs | |
| parent | NFS4: Avoid potential NULL pointer dereference in decode_and_add_ds(). (diff) | |
| download | linux-839f7ad6932d95f4d5ae7267b95c574714ff3d5b.tar.xz linux-839f7ad6932d95f4d5ae7267b95c574714ff3d5b.zip | |
NFS: Fix "kernel BUG at fs/aio.c:554!"
Nick Piggin reports:
> I'm getting use after frees in aio code in NFS
>
> [ 2703.396766] Call Trace:
> [ 2703.396858] [<ffffffff8100b057>] ? native_sched_clock+0x27/0x80
> [ 2703.396959] [<ffffffff8108509e>] ? put_lock_stats+0xe/0x40
> [ 2703.397058] [<ffffffff81088348>] ? lock_release_holdtime+0xa8/0x140
> [ 2703.397159] [<ffffffff8108a2a5>] lock_acquire+0x95/0x1b0
> [ 2703.397260] [<ffffffff811627db>] ? aio_put_req+0x2b/0x60
> [ 2703.397361] [<ffffffff81039701>] ? get_parent_ip+0x11/0x50
> [ 2703.397464] [<ffffffff81612a31>] _raw_spin_lock_irq+0x41/0x80
> [ 2703.397564] [<ffffffff811627db>] ? aio_put_req+0x2b/0x60
> [ 2703.397662] [<ffffffff811627db>] aio_put_req+0x2b/0x60
> [ 2703.397761] [<ffffffff811647fe>] do_io_submit+0x2be/0x7c0
> [ 2703.397895] [<ffffffff81164d0b>] sys_io_submit+0xb/0x10
> [ 2703.397995] [<ffffffff8100307b>] system_call_fastpath+0x16/0x1b
>
> Adding some tracing, it is due to nfs completing the request then
> returning something other than -EIOCBQUEUED, so aio.c
> also completes the request.
To address this, prevent the NFS direct I/O engine from completing
async iocbs when the forward path returns an error without starting
any I/O.
This fix appears to survive ^C during both "xfstest no. 208" and "fsx
-Z."
It's likely this bug has existed for a very long while, as we are seeing
very similar symptoms in OEL 5. Copying stable.
Cc: Stable <stable@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/direct.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index e6ace0d93c71..9943a75bb6d1 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -407,15 +407,18 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, pos += vec->iov_len; } + /* + * If no bytes were started, return the error, and let the + * generic layer handle the completion. + */ + if (requested_bytes == 0) { + nfs_direct_req_release(dreq); + return result < 0 ? result : -EIO; + } + if (put_dreq(dreq)) nfs_direct_complete(dreq); - - if (requested_bytes != 0) - return 0; - - if (result < 0) - return result; - return -EIO; + return 0; } static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, @@ -841,15 +844,18 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, pos += vec->iov_len; } + /* + * If no bytes were started, return the error, and let the + * generic layer handle the completion. + */ + if (requested_bytes == 0) { + nfs_direct_req_release(dreq); + return result < 0 ? result : -EIO; + } + if (put_dreq(dreq)) nfs_direct_write_complete(dreq, dreq->inode); - - if (requested_bytes != 0) - return 0; - - if (result < 0) - return result; - return -EIO; + return 0; } static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, |