1 files changed, 43 insertions, 51 deletions

diff --git a/fs/aio.c b/fs/aio.c
index aaaaf4d12c73..38b741aef0bf 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -167,9 +167,13 @@ struct kioctx {
 	unsigned		id;
 };
 
+/*
+ * First field must be the file pointer in all the
+ * iocb unions! See also 'struct kiocb' in <linux/fs.h>
+ */
 struct fsync_iocb {
-	struct work_struct	work;
 	struct file		*file;
+	struct work_struct	work;
 	bool			datasync;
 };
 
@@ -183,8 +187,15 @@ struct poll_iocb {
 	struct work_struct	work;
 };
 
+/*
+ * NOTE! Each of the iocb union members has the file pointer
+ * as the first entry in their struct definition. So you can
+ * access the file pointer through any of the sub-structs,
+ * or directly as just 'ki_filp' in this struct.
+ */
 struct aio_kiocb {
 	union {
+		struct file		*ki_filp;
 		struct kiocb		rw;
 		struct fsync_iocb	fsync;
 		struct poll_iocb	poll;
@@ -1060,6 +1071,8 @@ static inline void iocb_put(struct aio_kiocb *iocb)
 {
 	if (refcount_read(&iocb->ki_refcnt) == 0 ||
 	    refcount_dec_and_test(&iocb->ki_refcnt)) {
+		if (iocb->ki_filp)
+			fput(iocb->ki_filp);
 		percpu_ref_put(&iocb->ki_ctx->reqs);
 		kmem_cache_free(kiocb_cachep, iocb);
 	}
@@ -1424,7 +1437,6 @@ static void aio_complete_rw(struct kiocb *kiocb, long res, long res2)
 		file_end_write(kiocb->ki_filp);
 	}
 
-	fput(kiocb->ki_filp);
 	aio_complete(iocb, res, res2);
 }
 
@@ -1432,9 +1444,6 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 {
 	int ret;
 
-	req->ki_filp = fget(iocb->aio_fildes);
-	if (unlikely(!req->ki_filp))
-		return -EBADF;
 	req->ki_complete = aio_complete_rw;
 	req->private = NULL;
 	req->ki_pos = iocb->aio_offset;
@@ -1451,7 +1460,7 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 		ret = ioprio_check_cap(iocb->aio_reqprio);
 		if (ret) {
 			pr_debug("aio ioprio check cap error: %d\n", ret);
-			goto out_fput;
+			return ret;
 		}
 
 		req->ki_ioprio = iocb->aio_reqprio;
@@ -1460,14 +1469,10 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 
 	ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
 	if (unlikely(ret))
-		goto out_fput;
+		return ret;
 
 	req->ki_flags &= ~IOCB_HIPRI; /* no one is going to poll for this I/O */
 	return 0;
-
-out_fput:
-	fput(req->ki_filp);
-	return ret;
 }
 
 static int aio_setup_rw(int rw, const struct iocb *iocb, struct iovec **iovec,
@@ -1521,24 +1526,19 @@ static ssize_t aio_read(struct kiocb *req, const struct iocb *iocb,
 	if (ret)
 		return ret;
 	file = req->ki_filp;
-
-	ret = -EBADF;
 	if (unlikely(!(file->f_mode & FMODE_READ)))
-		goto out_fput;
+		return -EBADF;
 	ret = -EINVAL;
 	if (unlikely(!file->f_op->read_iter))
-		goto out_fput;
+		return -EINVAL;
 
 	ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter);
 	if (ret)
-		goto out_fput;
+		return ret;
 	ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
 	if (!ret)
 		aio_rw_done(req, call_read_iter(file, req, &iter));
 	kfree(iovec);
-out_fput:
-	if (unlikely(ret))
-		fput(file);
 	return ret;
 }
 
@@ -1555,16 +1555,14 @@ static ssize_t aio_write(struct kiocb *req, const struct iocb *iocb,
 		return ret;
 	file = req->ki_filp;
 
-	ret = -EBADF;
 	if (unlikely(!(file->f_mode & FMODE_WRITE)))
-		goto out_fput;
-	ret = -EINVAL;
+		return -EBADF;
 	if (unlikely(!file->f_op->write_iter))
-		goto out_fput;
+		return -EINVAL;
 
 	ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter);
 	if (ret)
-		goto out_fput;
+		return ret;
 	ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
 	if (!ret) {
 		/*
@@ -1582,9 +1580,6 @@ static ssize_t aio_write(struct kiocb *req, const struct iocb *iocb,
 		aio_rw_done(req, call_write_iter(file, req, &iter));
 	}
 	kfree(iovec);
-out_fput:
-	if (unlikely(ret))
-		fput(file);
 	return ret;
 }
 
@@ -1594,7 +1589,6 @@ static void aio_fsync_work(struct work_struct *work)
 	int ret;
 
 	ret = vfs_fsync(req->file, req->datasync);
-	fput(req->file);
 	aio_complete(container_of(req, struct aio_kiocb, fsync), ret, 0);
 }
 
@@ -1605,13 +1599,8 @@ static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
 			iocb->aio_rw_flags))
 		return -EINVAL;
 
-	req->file = fget(iocb->aio_fildes);
-	if (unlikely(!req->file))
-		return -EBADF;
-	if (unlikely(!req->file->f_op->fsync)) {
-		fput(req->file);
+	if (unlikely(!req->file->f_op->fsync))
 		return -EINVAL;
-	}
 
 	req->datasync = datasync;
 	INIT_WORK(&req->work, aio_fsync_work);
@@ -1621,10 +1610,7 @@ static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
 
 static inline void aio_poll_complete(struct aio_kiocb *iocb, __poll_t mask)
 {
-	struct file *file = iocb->poll.file;
-
 	aio_complete(iocb, mangle_poll(mask), 0);
-	fput(file);
 }
 
 static void aio_poll_complete_work(struct work_struct *work)
@@ -1680,6 +1666,7 @@ static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
 	struct poll_iocb *req = container_of(wait, struct poll_iocb, wait);
 	struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
 	__poll_t mask = key_to_poll(key);
+	unsigned long flags;
 
 	req->woken = true;
 
@@ -1688,10 +1675,15 @@ static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
 		if (!(mask & req->events))
 			return 0;
 
-		/* try to complete the iocb inline if we can: */
-		if (spin_trylock(&iocb->ki_ctx->ctx_lock)) {
+		/*
+		 * Try to complete the iocb inline if we can. Use
+		 * irqsave/irqrestore because not all filesystems (e.g. fuse)
+		 * call this function with IRQs disabled and because IRQs
+		 * have to be disabled before ctx_lock is obtained.
+		 */
+		if (spin_trylock_irqsave(&iocb->ki_ctx->ctx_lock, flags)) {
 			list_del(&iocb->ki_list);
-			spin_unlock(&iocb->ki_ctx->ctx_lock);
+			spin_unlock_irqrestore(&iocb->ki_ctx->ctx_lock, flags);
 
 			list_del_init(&req->wait.entry);
 			aio_poll_complete(iocb, mask);
@@ -1743,9 +1735,6 @@ static ssize_t aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)
 
 	INIT_WORK(&req->work, aio_poll_complete_work);
 	req->events = demangle_poll(iocb->aio_buf) | EPOLLERR | EPOLLHUP;
-	req->file = fget(iocb->aio_fildes);
-	if (unlikely(!req->file))
-		return -EBADF;
 
 	req->head = NULL;
 	req->woken = false;
@@ -1788,10 +1777,8 @@ static ssize_t aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)
 	spin_unlock_irq(&ctx->ctx_lock);
 
 out:
-	if (unlikely(apt.error)) {
-		fput(req->file);
+	if (unlikely(apt.error))
 		return apt.error;
-	}
 
 	if (mask)
 		aio_poll_complete(aiocb, mask);
@@ -1829,6 +1816,11 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
 	if (unlikely(!req))
 		goto out_put_reqs_available;
 
+	req->ki_filp = fget(iocb->aio_fildes);
+	ret = -EBADF;
+	if (unlikely(!req->ki_filp))
+		goto out_put_req;
+
 	if (iocb->aio_flags & IOCB_FLAG_RESFD) {
 		/*
 		 * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
@@ -2199,11 +2191,11 @@ SYSCALL_DEFINE6(io_pgetevents_time32,
 
 #if defined(CONFIG_COMPAT_32BIT_TIME)
 
-COMPAT_SYSCALL_DEFINE5(io_getevents, compat_aio_context_t, ctx_id,
-		       compat_long_t, min_nr,
-		       compat_long_t, nr,
-		       struct io_event __user *, events,
-		       struct old_timespec32 __user *, timeout)
+SYSCALL_DEFINE5(io_getevents_time32, __u32, ctx_id,
+		__s32, min_nr,
+		__s32, nr,
+		struct io_event __user *, events,
+		struct old_timespec32 __user *, timeout)
 {
 	struct timespec64 t;
 	int ret;