diff options
| -rw-r--r-- | fs/nfs/direct.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 6cbddc51acbc..094456c3df90 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -177,6 +177,7 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize) kref_init(&dreq->kref); init_waitqueue_head(&dreq->wait); INIT_LIST_HEAD(&dreq->list); + dreq->iocb = NULL; atomic_set(&dreq->count, 0); atomic_set(&dreq->error, 0); @@ -213,6 +214,10 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize) * We must hold a reference to all the pages in this direct read request * until the RPCs complete. This could be long *after* we are woken up in * nfs_direct_read_wait (for instance, if someone hits ^C on a slow server). + * + * In addition, synchronous I/O uses a stack-allocated iocb. Thus we + * can't trust the iocb is still valid here if this is a synchronous + * request. If the waiter is woken prematurely, the iocb is long gone. */ static void nfs_direct_read_result(struct rpc_task *task, void *calldata) { @@ -228,7 +233,13 @@ static void nfs_direct_read_result(struct rpc_task *task, void *calldata) if (unlikely(atomic_dec_and_test(&dreq->complete))) { nfs_free_user_pages(dreq->pages, dreq->npages, 1); - wake_up(&dreq->wait); + if (dreq->iocb) { + long res = atomic_read(&dreq->error); + if (!res) + res = atomic_read(&dreq->count); + aio_complete(dreq->iocb, res, 0); + } else + wake_up(&dreq->wait); kref_put(&dreq->kref, nfs_direct_req_release); } } @@ -309,8 +320,13 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long */ static ssize_t nfs_direct_read_wait(struct nfs_direct_req *dreq, int intr) { - int result = 0; + int result = -EIOCBQUEUED; + + /* Async requests don't wait here */ + if (dreq->iocb) + goto out; + result = 0; if (intr) { result = wait_event_interruptible(dreq->wait, (atomic_read(&dreq->complete) == 0)); @@ -323,6 +339,7 @@ static ssize_t nfs_direct_read_wait(struct nfs_direct_req *dreq, int intr) if (!result) result = atomic_read(&dreq->count); +out: kref_put(&dreq->kref, nfs_direct_req_release); return (ssize_t) result; } @@ -343,6 +360,8 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size dreq->npages = nr_pages; dreq->inode = inode; dreq->filp = iocb->ki_filp; + if (!is_sync_kiocb(iocb)) + dreq->iocb = iocb; nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); rpc_clnt_sigmask(clnt, &oldset); @@ -534,8 +553,6 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, file->f_dentry->d_name.name, (unsigned long) count, (long long) pos); - if (!is_sync_kiocb(iocb)) - goto out; if (count < 0) goto out; retval = -EFAULT; |