1 files changed, 158 insertions, 125 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 562916d85cba..0a23a8c0717f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -80,7 +80,7 @@ struct aio_ring {
 struct kioctx_table {
 	struct rcu_head		rcu;
 	unsigned		nr;
-	struct kioctx __rcu	*table[];
+	struct kioctx __rcu	*table[] __counted_by(nr);
 };
 
 struct kioctx_cpu {
@@ -100,7 +100,7 @@ struct kioctx {
 
 	unsigned long		user_id;
 
-	struct __percpu kioctx_cpu *cpu;
+	struct kioctx_cpu __percpu *cpu;
 
 	/*
 	 * For percpu reqs_available, number of slots we move to/from global
@@ -122,7 +122,7 @@ struct kioctx {
 	unsigned long		mmap_base;
 	unsigned long		mmap_size;
 
-	struct page		**ring_pages;
+	struct folio		**ring_folios;
 	long			nr_pages;
 
 	struct rcu_work		free_rwork;	/* see free_ioctx() */
@@ -160,7 +160,7 @@ struct kioctx {
 		spinlock_t	completion_lock;
 	} ____cacheline_aligned_in_smp;
 
-	struct page		*internal_pages[AIO_RING_PAGES];
+	struct folio		*internal_folios[AIO_RING_PAGES];
 	struct file		*aio_ring_file;
 
 	unsigned		id;
@@ -224,7 +224,7 @@ static unsigned long aio_nr;		/* current system wide number of aio requests */
 static unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
 /*----end sysctl variables---*/
 #ifdef CONFIG_SYSCTL
-static struct ctl_table aio_sysctls[] = {
+static const struct ctl_table aio_sysctls[] = {
 	{
 		.procname	= "aio-nr",
 		.data		= &aio_nr,
@@ -239,7 +239,6 @@ static struct ctl_table aio_sysctls[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_doulongvec_minmax,
 	},
-	{}
 };
 
 static void __init aio_sysctl_init(void)
@@ -266,7 +265,7 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
 		return ERR_CAST(inode);
 
 	inode->i_mapping->a_ops = &aio_ctx_aops;
-	inode->i_mapping->private_data = ctx;
+	inode->i_mapping->i_private_data = ctx;
 	inode->i_size = PAGE_SIZE * nr_pages;
 
 	file = alloc_file_pseudo(inode, aio_mnt, "[aio]",
@@ -316,10 +315,10 @@ static void put_aio_ring_file(struct kioctx *ctx)
 
 		/* Prevent further access to the kioctx from migratepages */
 		i_mapping = aio_ring_file->f_mapping;
-		spin_lock(&i_mapping->private_lock);
-		i_mapping->private_data = NULL;
+		spin_lock(&i_mapping->i_private_lock);
+		i_mapping->i_private_data = NULL;
 		ctx->aio_ring_file = NULL;
-		spin_unlock(&i_mapping->private_lock);
+		spin_unlock(&i_mapping->i_private_lock);
 
 		fput(aio_ring_file);
 	}
@@ -335,19 +334,20 @@ static void aio_free_ring(struct kioctx *ctx)
 	put_aio_ring_file(ctx);
 
 	for (i = 0; i < ctx->nr_pages; i++) {
-		struct page *page;
-		pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
-				page_count(ctx->ring_pages[i]));
-		page = ctx->ring_pages[i];
-		if (!page)
+		struct folio *folio = ctx->ring_folios[i];
+
+		if (!folio)
 			continue;
-		ctx->ring_pages[i] = NULL;
-		put_page(page);
+
+		pr_debug("pid(%d) [%d] folio->count=%d\n", current->pid, i,
+			 folio_ref_count(folio));
+		ctx->ring_folios[i] = NULL;
+		folio_put(folio);
 	}
 
-	if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
-		kfree(ctx->ring_pages);
-		ctx->ring_pages = NULL;
+	if (ctx->ring_folios && ctx->ring_folios != ctx->internal_folios) {
+		kfree(ctx->ring_folios);
+		ctx->ring_folios = NULL;
 	}
 }
 
@@ -361,6 +361,9 @@ static int aio_ring_mremap(struct vm_area_struct *vma)
 	spin_lock(&mm->ioctx_lock);
 	rcu_read_lock();
 	table = rcu_dereference(mm->ioctx_table);
+	if (!table)
+		goto out_unlock;
+
 	for (i = 0; i < table->nr; i++) {
 		struct kioctx *ctx;
 
@@ -374,6 +377,7 @@ static int aio_ring_mremap(struct vm_area_struct *vma)
 		}
 	}
 
+out_unlock:
 	rcu_read_unlock();
 	spin_unlock(&mm->ioctx_lock);
 	return res;
@@ -388,15 +392,15 @@ static const struct vm_operations_struct aio_ring_vm_ops = {
 #endif
 };
 
-static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
+static int aio_ring_mmap_prepare(struct vm_area_desc *desc)
 {
-	vma->vm_flags |= VM_DONTEXPAND;
-	vma->vm_ops = &aio_ring_vm_ops;
+	desc->vm_flags |= VM_DONTEXPAND;
+	desc->vm_ops = &aio_ring_vm_ops;
 	return 0;
 }
 
 static const struct file_operations aio_ring_fops = {
-	.mmap = aio_ring_mmap,
+	.mmap_prepare = aio_ring_mmap_prepare,
 };
 
 #if IS_ENABLED(CONFIG_MIGRATION)
@@ -406,21 +410,11 @@ static int aio_migrate_folio(struct address_space *mapping, struct folio *dst,
 	struct kioctx *ctx;
 	unsigned long flags;
 	pgoff_t idx;
-	int rc;
+	int rc = 0;
 
-	/*
-	 * We cannot support the _NO_COPY case here, because copy needs to
-	 * happen under the ctx->completion_lock. That does not work with the
-	 * migration workflow of MIGRATE_SYNC_NO_COPY.
-	 */
-	if (mode == MIGRATE_SYNC_NO_COPY)
-		return -EINVAL;
-
-	rc = 0;
-
-	/* mapping->private_lock here protects against the kioctx teardown.  */
-	spin_lock(&mapping->private_lock);
-	ctx = mapping->private_data;
+	/* mapping->i_private_lock here protects against the kioctx teardown.  */
+	spin_lock(&mapping->i_private_lock);
+	ctx = mapping->i_private_data;
 	if (!ctx) {
 		rc = -EINVAL;
 		goto out;
@@ -438,7 +432,7 @@ static int aio_migrate_folio(struct address_space *mapping, struct folio *dst,
 	idx = src->index;
 	if (idx < (pgoff_t)ctx->nr_pages) {
 		/* Make sure the old folio hasn't already been changed */
-		if (ctx->ring_pages[idx] != &src->page)
+		if (ctx->ring_folios[idx] != src)
 			rc = -EAGAIN;
 	} else
 		rc = -EINVAL;
@@ -451,7 +445,7 @@ static int aio_migrate_folio(struct address_space *mapping, struct folio *dst,
 	folio_get(dst);
 
 	rc = folio_migrate_mapping(mapping, dst, src, 1);
-	if (rc != MIGRATEPAGE_SUCCESS) {
+	if (rc) {
 		folio_put(dst);
 		goto out_unlock;
 	}
@@ -461,9 +455,10 @@ static int aio_migrate_folio(struct address_space *mapping, struct folio *dst,
 	 * events from being lost.
 	 */
 	spin_lock_irqsave(&ctx->completion_lock, flags);
-	folio_migrate_copy(dst, src);
-	BUG_ON(ctx->ring_pages[idx] != &src->page);
-	ctx->ring_pages[idx] = &dst->page;
+	folio_copy(dst, src);
+	folio_migrate_flags(dst, src);
+	BUG_ON(ctx->ring_folios[idx] != src);
+	ctx->ring_folios[idx] = dst;
 	spin_unlock_irqrestore(&ctx->completion_lock, flags);
 
 	/* The old folio is no longer accessible. */
@@ -472,7 +467,7 @@ static int aio_migrate_folio(struct address_space *mapping, struct folio *dst,
 out_unlock:
 	mutex_unlock(&ctx->ring_lock);
 out:
-	spin_unlock(&mapping->private_lock);
+	spin_unlock(&mapping->i_private_lock);
 	return rc;
 }
 #else
@@ -513,28 +508,30 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 	nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
 			/ sizeof(struct io_event);
 
-	ctx->ring_pages = ctx->internal_pages;
+	ctx->ring_folios = ctx->internal_folios;
 	if (nr_pages > AIO_RING_PAGES) {
-		ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
-					  GFP_KERNEL);
-		if (!ctx->ring_pages) {
+		ctx->ring_folios = kcalloc(nr_pages, sizeof(struct folio *),
+					   GFP_KERNEL);
+		if (!ctx->ring_folios) {
 			put_aio_ring_file(ctx);
 			return -ENOMEM;
 		}
 	}
 
 	for (i = 0; i < nr_pages; i++) {
-		struct page *page;
-		page = find_or_create_page(file->f_mapping,
-					   i, GFP_HIGHUSER | __GFP_ZERO);
-		if (!page)
+		struct folio *folio;
+
+		folio = __filemap_get_folio(file->f_mapping, i,
+					    FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
+					    GFP_USER | __GFP_ZERO);
+		if (IS_ERR(folio))
 			break;
-		pr_debug("pid(%d) page[%d]->count=%d\n",
-			 current->pid, i, page_count(page));
-		SetPageUptodate(page);
-		unlock_page(page);
 
-		ctx->ring_pages[i] = page;
+		pr_debug("pid(%d) [%d] folio->count=%d\n", current->pid, i,
+			 folio_ref_count(folio));
+		folio_end_read(folio, true);
+
+		ctx->ring_folios[i] = folio;
 	}
 	ctx->nr_pages = i;
 
@@ -554,7 +551,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 
 	ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size,
 				 PROT_READ | PROT_WRITE,
-				 MAP_SHARED, 0, &unused, NULL);
+				 MAP_SHARED, 0, 0, &unused, NULL);
 	mmap_write_unlock(mm);
 	if (IS_ERR((void *)ctx->mmap_base)) {
 		ctx->mmap_size = 0;
@@ -567,7 +564,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 	ctx->user_id = ctx->mmap_base;
 	ctx->nr_events = nr_events; /* trusted copy */
 
-	ring = kmap_atomic(ctx->ring_pages[0]);
+	ring = folio_address(ctx->ring_folios[0]);
 	ring->nr = nr_events;	/* user copy */
 	ring->id = ~0U;
 	ring->head = ring->tail = 0;
@@ -575,8 +572,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 	ring->compat_features = AIO_RING_COMPAT_FEATURES;
 	ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
 	ring->header_length = sizeof(struct aio_ring);
-	kunmap_atomic(ring);
-	flush_dcache_page(ctx->ring_pages[0]);
+	flush_dcache_folio(ctx->ring_folios[0]);
 
 	return 0;
 }
@@ -587,13 +583,24 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 
 void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
 {
-	struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw);
-	struct kioctx *ctx = req->ki_ctx;
+	struct aio_kiocb *req;
+	struct kioctx *ctx;
 	unsigned long flags;
 
+	/*
+	 * kiocb didn't come from aio or is neither a read nor a write, hence
+	 * ignore it.
+	 */
+	if (!(iocb->ki_flags & IOCB_AIO_RW))
+		return;
+
+	req = container_of(iocb, struct aio_kiocb, rw);
+
 	if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
 		return;
 
+	ctx = req->ki_ctx;
+
 	spin_lock_irqsave(&ctx->ctx_lock, flags);
 	list_add_tail(&req->ki_list, &ctx->active_reqs);
 	req->ki_cancel = cancel;
@@ -629,7 +636,7 @@ static void free_ioctx_reqs(struct percpu_ref *ref)
 
 	/* Synchronize against RCU protected table->table[] dereferences */
 	INIT_RCU_WORK(&ctx->free_rwork, free_ioctx);
-	queue_rcu_work(system_wq, &ctx->free_rwork);
+	queue_rcu_work(system_percpu_wq, &ctx->free_rwork);
 }
 
 /*
@@ -676,11 +683,10 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
 
 					/* While kioctx setup is in progress,
 					 * we are protected from page migration
-					 * changes ring_pages by ->ring_lock.
+					 * changes ring_folios by ->ring_lock.
 					 */
-					ring = kmap_atomic(ctx->ring_pages[0]);
+					ring = folio_address(ctx->ring_folios[0]);
 					ring->id = ctx->id;
-					kunmap_atomic(ring);
 					return 0;
 				}
 
@@ -1021,9 +1027,8 @@ static void user_refill_reqs_available(struct kioctx *ctx)
 		 * against ctx->completed_events below will make sure we do the
 		 * safe/right thing.
 		 */
-		ring = kmap_atomic(ctx->ring_pages[0]);
+		ring = folio_address(ctx->ring_folios[0]);
 		head = ring->head;
-		kunmap_atomic(ring);
 
 		refill_reqs_available(ctx, head, ctx->tail);
 	}
@@ -1105,6 +1110,11 @@ static inline void iocb_destroy(struct aio_kiocb *iocb)
 	kmem_cache_free(kiocb_cachep, iocb);
 }
 
+struct aio_waiter {
+	struct wait_queue_entry	w;
+	size_t			min_nr;
+};
+
 /* aio_complete
  *	Called when the io request on the given iocb is complete.
  */
@@ -1113,7 +1123,7 @@ static void aio_complete(struct aio_kiocb *iocb)
 	struct kioctx	*ctx = iocb->ki_ctx;
 	struct aio_ring	*ring;
 	struct io_event	*ev_page, *event;
-	unsigned tail, pos, head;
+	unsigned tail, pos, head, avail;
 	unsigned long	flags;
 
 	/*
@@ -1129,13 +1139,12 @@ static void aio_complete(struct aio_kiocb *iocb)
 	if (++tail >= ctx->nr_events)
 		tail = 0;
 
-	ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
+	ev_page = folio_address(ctx->ring_folios[pos / AIO_EVENTS_PER_PAGE]);
 	event = ev_page + pos % AIO_EVENTS_PER_PAGE;
 
 	*event = iocb->ki_res;
 
-	kunmap_atomic(ev_page);
-	flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
+	flush_dcache_folio(ctx->ring_folios[pos / AIO_EVENTS_PER_PAGE]);
 
 	pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb,
 		 (void __user *)(unsigned long)iocb->ki_res.obj,
@@ -1148,15 +1157,18 @@ static void aio_complete(struct aio_kiocb *iocb)
 
 	ctx->tail = tail;
 
-	ring = kmap_atomic(ctx->ring_pages[0]);
+	ring = folio_address(ctx->ring_folios[0]);
 	head = ring->head;
 	ring->tail = tail;
-	kunmap_atomic(ring);
-	flush_dcache_page(ctx->ring_pages[0]);
+	flush_dcache_folio(ctx->ring_folios[0]);
 
 	ctx->completed_events++;
 	if (ctx->completed_events > 1)
 		refill_reqs_available(ctx, head, tail);
+
+	avail = tail > head
+		? tail - head
+		: tail + ctx->nr_events - head;
 	spin_unlock_irqrestore(&ctx->completion_lock, flags);
 
 	pr_debug("added to ring %p at [%u]\n", iocb, tail);
@@ -1167,7 +1179,7 @@ static void aio_complete(struct aio_kiocb *iocb)
 	 * from IRQ context.
 	 */
 	if (iocb->ki_eventfd)
-		eventfd_signal(iocb->ki_eventfd, 1);
+		eventfd_signal(iocb->ki_eventfd);
 
 	/*
 	 * We have to order our ring_info tail store above and test
@@ -1177,8 +1189,18 @@ static void aio_complete(struct aio_kiocb *iocb)
 	 */
 	smp_mb();
 
-	if (waitqueue_active(&ctx->wait))
-		wake_up(&ctx->wait);
+	if (waitqueue_active(&ctx->wait)) {
+		struct aio_waiter *curr, *next;
+		unsigned long flags;
+
+		spin_lock_irqsave(&ctx->wait.lock, flags);
+		list_for_each_entry_safe(curr, next, &ctx->wait.head, w.entry)
+			if (avail >= curr->min_nr) {
+				wake_up_process(curr->w.private);
+				list_del_init_careful(&curr->w.entry);
+			}
+		spin_unlock_irqrestore(&ctx->wait.lock, flags);
+	}
 }
 
 static inline void iocb_put(struct aio_kiocb *iocb)
@@ -1210,11 +1232,10 @@ static long aio_read_events_ring(struct kioctx *ctx,
 	sched_annotate_sleep();
 	mutex_lock(&ctx->ring_lock);
 
-	/* Access to ->ring_pages here is protected by ctx->ring_lock. */
-	ring = kmap_atomic(ctx->ring_pages[0]);
+	/* Access to ->ring_folios here is protected by ctx->ring_lock. */
+	ring = folio_address(ctx->ring_folios[0]);
 	head = ring->head;
 	tail = ring->tail;
-	kunmap_atomic(ring);
 
 	/*
 	 * Ensure that once we've read the current tail pointer, that
@@ -1233,23 +1254,22 @@ static long aio_read_events_ring(struct kioctx *ctx,
 	while (ret < nr) {
 		long avail;
 		struct io_event *ev;
-		struct page *page;
+		struct folio *folio;
 
 		avail = (head <= tail ?  tail : ctx->nr_events) - head;
 		if (head == tail)
 			break;
 
 		pos = head + AIO_EVENTS_OFFSET;
-		page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
+		folio = ctx->ring_folios[pos / AIO_EVENTS_PER_PAGE];
 		pos %= AIO_EVENTS_PER_PAGE;
 
 		avail = min(avail, nr - ret);
 		avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - pos);
 
-		ev = kmap(page);
+		ev = folio_address(folio);
 		copy_ret = copy_to_user(event + ret, ev + pos,
 					sizeof(*ev) * avail);
-		kunmap(page);
 
 		if (unlikely(copy_ret)) {
 			ret = -EFAULT;
@@ -1261,10 +1281,9 @@ static long aio_read_events_ring(struct kioctx *ctx,
 		head %= ctx->nr_events;
 	}
 
-	ring = kmap_atomic(ctx->ring_pages[0]);
+	ring = folio_address(ctx->ring_folios[0]);
 	ring->head = head;
-	kunmap_atomic(ring);
-	flush_dcache_page(ctx->ring_pages[0]);
+	flush_dcache_folio(ctx->ring_folios[0]);
 
 	pr_debug("%li  h%u t%u\n", ret, head, tail);
 out:
@@ -1294,7 +1313,9 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
 			struct io_event __user *event,
 			ktime_t until)
 {
-	long ret = 0;
+	struct hrtimer_sleeper	t;
+	struct aio_waiter	w;
+	long ret = 0, ret2 = 0;
 
 	/*
 	 * Note that aio_read_events() is being called as the conditional - i.e.
@@ -1310,12 +1331,38 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
 	 * the ringbuffer empty. So in practice we should be ok, but it's
 	 * something to be aware of when touching this code.
 	 */
-	if (until == 0)
-		aio_read_events(ctx, min_nr, nr, event, &ret);
-	else
-		wait_event_interruptible_hrtimeout(ctx->wait,
-				aio_read_events(ctx, min_nr, nr, event, &ret),
-				until);
+	aio_read_events(ctx, min_nr, nr, event, &ret);
+	if (until == 0 || ret < 0 || ret >= min_nr)
+		return ret;
+
+	hrtimer_setup_sleeper_on_stack(&t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	if (until != KTIME_MAX) {
+		hrtimer_set_expires_range_ns(&t.timer, until, current->timer_slack_ns);
+		hrtimer_sleeper_start_expires(&t, HRTIMER_MODE_REL);
+	}
+
+	init_wait(&w.w);
+
+	while (1) {
+		unsigned long nr_got = ret;
+
+		w.min_nr = min_nr - ret;
+
+		ret2 = prepare_to_wait_event(&ctx->wait, &w.w, TASK_INTERRUPTIBLE);
+		if (!ret2 && !t.task)
+			ret2 = -ETIME;
+
+		if (aio_read_events(ctx, min_nr, nr, event, &ret) || ret2)
+			break;
+
+		if (nr_got == ret)
+			schedule();
+	}
+
+	finish_wait(&ctx->wait, &w.w);
+	hrtimer_cancel(&t.timer);
+	destroy_hrtimer_on_stack(&t.timer);
+
 	return ret;
 }
 
@@ -1451,13 +1498,8 @@ static void aio_complete_rw(struct kiocb *kiocb, long res)
 	if (kiocb->ki_flags & IOCB_WRITE) {
 		struct inode *inode = file_inode(kiocb->ki_filp);
 
-		/*
-		 * Tell lockdep we inherited freeze protection from submission
-		 * thread.
-		 */
 		if (S_ISREG(inode->i_mode))
-			__sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
-		file_end_write(kiocb->ki_filp);
+			kiocb_end_write(kiocb);
 	}
 
 	iocb->ki_res.res = res;
@@ -1465,14 +1507,15 @@ static void aio_complete_rw(struct kiocb *kiocb, long res)
 	iocb_put(iocb);
 }
 
-static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
+static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb, int rw_type)
 {
 	int ret;
 
+	req->ki_write_stream = 0;
 	req->ki_complete = aio_complete_rw;
 	req->private = NULL;
 	req->ki_pos = iocb->aio_offset;
-	req->ki_flags = req->ki_filp->f_iocb_flags;
+	req->ki_flags = req->ki_filp->f_iocb_flags | IOCB_AIO_RW;
 	if (iocb->aio_flags & IOCB_FLAG_RESFD)
 		req->ki_flags |= IOCB_EVENTFD;
 	if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
@@ -1491,7 +1534,7 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 	} else
 		req->ki_ioprio = get_current_ioprio();
 
-	ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
+	ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags, rw_type);
 	if (unlikely(ret))
 		return ret;
 
@@ -1507,7 +1550,7 @@ static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
 	size_t len = iocb->aio_nbytes;
 
 	if (!vectored) {
-		ssize_t ret = import_single_range(rw, buf, len, *iovec, iter);
+		ssize_t ret = import_ubuf(rw, buf, len, iter);
 		*iovec = NULL;
 		return ret;
 	}
@@ -1543,7 +1586,7 @@ static int aio_read(struct kiocb *req, const struct iocb *iocb,
 	struct file *file;
 	int ret;
 
-	ret = aio_prep_rw(req, iocb);
+	ret = aio_prep_rw(req, iocb, READ);
 	if (ret)
 		return ret;
 	file = req->ki_filp;
@@ -1557,7 +1600,7 @@ static int aio_read(struct kiocb *req, const struct iocb *iocb,
 		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));
+		aio_rw_done(req, file->f_op->read_iter(req, &iter));
 	kfree(iovec);
 	return ret;
 }
@@ -1570,7 +1613,7 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
 	struct file *file;
 	int ret;
 
-	ret = aio_prep_rw(req, iocb);
+	ret = aio_prep_rw(req, iocb, WRITE);
 	if (ret)
 		return ret;
 	file = req->ki_filp;
@@ -1585,19 +1628,10 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
 		return ret;
 	ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
 	if (!ret) {
-		/*
-		 * Open-code file_start_write here to grab freeze protection,
-		 * which will be released by another thread in
-		 * aio_complete_rw().  Fool lockdep by telling it the lock got
-		 * released so that it doesn't complain about the held lock when
-		 * we return to userspace.
-		 */
-		if (S_ISREG(file_inode(file)->i_mode)) {
-			sb_start_write(file_inode(file)->i_sb);
-			__sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
-		}
+		if (S_ISREG(file_inode(file)->i_mode))
+			kiocb_start_write(req);
 		req->ki_flags |= IOCB_WRITE;
-		aio_rw_done(req, call_write_iter(file, req, &iter));
+		aio_rw_done(req, file->f_op->write_iter(req, &iter));
 	}
 	kfree(iovec);
 	return ret;
@@ -1606,10 +1640,10 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
 static void aio_fsync_work(struct work_struct *work)
 {
 	struct aio_kiocb *iocb = container_of(work, struct aio_kiocb, fsync.work);
-	const struct cred *old_cred = override_creds(iocb->fsync.creds);
 
-	iocb->ki_res.res = vfs_fsync(iocb->fsync.file, iocb->fsync.datasync);
-	revert_creds(old_cred);
+	scoped_with_creds(iocb->fsync.creds)
+		iocb->ki_res.res = vfs_fsync(iocb->fsync.file, iocb->fsync.datasync);
+
 	put_cred(iocb->fsync.creds);
 	iocb_put(iocb);
 }
@@ -2158,7 +2192,6 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
 		return -EINVAL;
 
 	spin_lock_irq(&ctx->ctx_lock);
-	/* TODO: use a hash or array, this sucks. */
 	list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) {
 		if (kiocb->ki_res.obj == obj) {
 			ret = kiocb->ki_cancel(&kiocb->rw);