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author | Chuck Lever <chuck.lever@oracle.com> | 2011-01-21 15:54:57 +0000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-17 15:37:00 -0800 |
commit | b365683faf48505e05fdd48001ccf5dbd22aeabd (patch) | |
tree | 4b64669a8fd52c8f1f506c3cc1a488c6f6256e98 /fs | |
parent | 3680eb53aaa92d88d06bb6f50ef3be0b8b2628dc (diff) | |
download | lwn-b365683faf48505e05fdd48001ccf5dbd22aeabd.tar.gz lwn-b365683faf48505e05fdd48001ccf5dbd22aeabd.zip |
NFS: Fix "kernel BUG at fs/aio.c:554!"
commit 839f7ad6932d95f4d5ae7267b95c574714ff3d5b upstream.
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.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 0d289823e856..e74a670d7a14 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -401,15 +401,18 @@ 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, @@ -829,15 +832,18 @@ 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, |