1 files changed, 315 insertions, 203 deletions

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 27aee92f3eea..41a832dd1426 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -31,6 +31,16 @@
 
 #include <trace/events/vb2.h>
 
+#define PLANE_INDEX_BITS	3
+#define PLANE_INDEX_SHIFT	(PAGE_SHIFT + PLANE_INDEX_BITS)
+#define PLANE_INDEX_MASK	(BIT_MASK(PLANE_INDEX_BITS) - 1)
+#define MAX_BUFFER_INDEX	BIT_MASK(30 - PLANE_INDEX_SHIFT)
+#define BUFFER_INDEX_MASK	(MAX_BUFFER_INDEX - 1)
+
+#if BIT(PLANE_INDEX_BITS) != VIDEO_MAX_PLANES
+#error PLANE_INDEX_BITS order must be equal to VIDEO_MAX_PLANES
+#endif
+
 static int debug;
 module_param(debug, int, 0644);
 
@@ -356,23 +366,29 @@ static void __setup_offsets(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
 	unsigned int plane;
-	unsigned long off = 0;
-
-	if (vb->index) {
-		struct vb2_buffer *prev = q->bufs[vb->index - 1];
-		struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
+	unsigned long offset = 0;
 
-		off = PAGE_ALIGN(p->m.offset + p->length);
-	}
+	/*
+	 * The offset "cookie" value has the following constraints:
+	 * - a buffer can have up to 8 planes.
+	 * - v4l2 mem2mem uses bit 30 to distinguish between
+	 *   OUTPUT (aka "source", bit 30 is 0) and
+	 *   CAPTURE (aka "destination", bit 30 is 1) buffers.
+	 * - must be page aligned
+	 * That led to this bit mapping when PAGE_SHIFT = 12:
+	 * |30                |29        15|14       12|11 0|
+	 * |DST_QUEUE_OFF_BASE|buffer index|plane index| 0  |
+	 * where there are 15 bits to store the buffer index.
+	 * Depending on PAGE_SHIFT value we can have fewer bits
+	 * to store the buffer index.
+	 */
+	offset = vb->index << PLANE_INDEX_SHIFT;
 
 	for (plane = 0; plane < vb->num_planes; ++plane) {
-		vb->planes[plane].m.offset = off;
+		vb->planes[plane].m.offset = offset + (plane << PAGE_SHIFT);
 
 		dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
-				vb->index, plane, off);
-
-		off += vb->planes[plane].length;
-		off = PAGE_ALIGN(off);
+				vb->index, plane, offset);
 	}
 }
 
@@ -397,6 +413,31 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
 		vb->skip_cache_sync_on_finish = 1;
 }
 
+/**
+ * vb2_queue_add_buffer() - add a buffer to a queue
+ * @q:	pointer to &struct vb2_queue with videobuf2 queue.
+ * @vb:	pointer to &struct vb2_buffer to be added to the queue.
+ * @index: index where add vb2_buffer in the queue
+ */
+static void vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, unsigned int index)
+{
+	WARN_ON(index >= q->max_num_buffers || q->bufs[index] || vb->vb2_queue);
+
+	q->bufs[index] = vb;
+	vb->index = index;
+	vb->vb2_queue = q;
+}
+
+/**
+ * vb2_queue_remove_buffer() - remove a buffer from a queue
+ * @vb:	pointer to &struct vb2_buffer to be removed from the queue.
+ */
+static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
+{
+	vb->vb2_queue->bufs[vb->index] = NULL;
+	vb->vb2_queue = NULL;
+}
+
 /*
  * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
  * video buffer memory for all buffers/planes on the queue and initializes the
@@ -408,13 +449,17 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 			     unsigned int num_buffers, unsigned int num_planes,
 			     const unsigned plane_sizes[VB2_MAX_PLANES])
 {
+	unsigned int q_num_buffers = vb2_get_num_buffers(q);
 	unsigned int buffer, plane;
 	struct vb2_buffer *vb;
 	int ret;
 
-	/* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
+	/*
+	 * Ensure that the number of already queue + the number of buffers already
+	 * in the queue is below q->max_num_buffers
+	 */
 	num_buffers = min_t(unsigned int, num_buffers,
-			    VB2_MAX_FRAME - q->num_buffers);
+			    q->max_num_buffers - q_num_buffers);
 
 	for (buffer = 0; buffer < num_buffers; ++buffer) {
 		/* Allocate vb2 buffer structures */
@@ -425,9 +470,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 		}
 
 		vb->state = VB2_BUF_STATE_DEQUEUED;
-		vb->vb2_queue = q;
 		vb->num_planes = num_planes;
-		vb->index = q->num_buffers + buffer;
 		vb->type = q->type;
 		vb->memory = memory;
 		init_buffer_cache_hints(q, vb);
@@ -435,9 +478,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 			vb->planes[plane].length = plane_sizes[plane];
 			vb->planes[plane].min_length = plane_sizes[plane];
 		}
-		call_void_bufop(q, init_buffer, vb);
 
-		q->bufs[vb->index] = vb;
+		vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
+		call_void_bufop(q, init_buffer, vb);
 
 		/* Allocate video buffer memory for the MMAP type */
 		if (memory == VB2_MEMORY_MMAP) {
@@ -445,7 +488,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 			if (ret) {
 				dprintk(q, 1, "failed allocating memory for buffer %d\n",
 					buffer);
-				q->bufs[vb->index] = NULL;
+				vb2_queue_remove_buffer(vb);
 				kfree(vb);
 				break;
 			}
@@ -460,7 +503,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 				dprintk(q, 1, "buffer %d %p initialization failed\n",
 					buffer, vb);
 				__vb2_buf_mem_free(vb);
-				q->bufs[vb->index] = NULL;
+				vb2_queue_remove_buffer(vb);
 				kfree(vb);
 				break;
 			}
@@ -480,10 +523,11 @@ static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 {
 	unsigned int buffer;
 	struct vb2_buffer *vb;
+	unsigned int q_num_buffers = vb2_get_num_buffers(q);
 
-	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	for (buffer = q_num_buffers - buffers; buffer < q_num_buffers;
 	     ++buffer) {
-		vb = q->bufs[buffer];
+		vb = vb2_get_buffer(q, buffer);
 		if (!vb)
 			continue;
 
@@ -505,13 +549,14 @@ static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 {
 	unsigned int buffer;
+	unsigned int q_num_buffers = vb2_get_num_buffers(q);
 
 	lockdep_assert_held(&q->mmap_lock);
 
 	/* Call driver-provided cleanup function for each buffer, if provided */
-	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	for (buffer = q_num_buffers - buffers; buffer < q_num_buffers;
 	     ++buffer) {
-		struct vb2_buffer *vb = q->bufs[buffer];
+		struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
 
 		if (vb && vb->planes[0].mem_priv)
 			call_void_vb_qop(vb, buf_cleanup, vb);
@@ -522,25 +567,26 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 
 #ifdef CONFIG_VIDEO_ADV_DEBUG
 	/*
-	 * Check that all the calls were balances during the life-time of this
-	 * queue. If not (or if the debug level is 1 or up), then dump the
-	 * counters to the kernel log.
+	 * Check that all the calls were balanced during the life-time of this
+	 * queue. If not then dump the counters to the kernel log.
 	 */
-	if (q->num_buffers) {
+	if (q_num_buffers) {
 		bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 				  q->cnt_prepare_streaming != q->cnt_unprepare_streaming ||
 				  q->cnt_wait_prepare != q->cnt_wait_finish;
 
-		if (unbalanced || debug) {
-			pr_info("counters for queue %p:%s\n", q,
-				unbalanced ? " UNBALANCED!" : "");
-			pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
-				q->cnt_queue_setup, q->cnt_start_streaming,
-				q->cnt_stop_streaming);
-			pr_info("     prepare_streaming: %u unprepare_streaming: %u\n",
-				q->cnt_prepare_streaming, q->cnt_unprepare_streaming);
-			pr_info("     wait_prepare: %u wait_finish: %u\n",
-				q->cnt_wait_prepare, q->cnt_wait_finish);
+		if (unbalanced) {
+			pr_info("unbalanced counters for queue %p:\n", q);
+			if (q->cnt_start_streaming != q->cnt_stop_streaming)
+				pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
+					q->cnt_queue_setup, q->cnt_start_streaming,
+					q->cnt_stop_streaming);
+			if (q->cnt_prepare_streaming != q->cnt_unprepare_streaming)
+				pr_info("     prepare_streaming: %u unprepare_streaming: %u\n",
+					q->cnt_prepare_streaming, q->cnt_unprepare_streaming);
+			if (q->cnt_wait_prepare != q->cnt_wait_finish)
+				pr_info("     wait_prepare: %u wait_finish: %u\n",
+					q->cnt_wait_prepare, q->cnt_wait_finish);
 		}
 		q->cnt_queue_setup = 0;
 		q->cnt_wait_prepare = 0;
@@ -550,53 +596,71 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 		q->cnt_stop_streaming = 0;
 		q->cnt_unprepare_streaming = 0;
 	}
-	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
-		struct vb2_buffer *vb = q->bufs[buffer];
-		bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
-				  vb->cnt_mem_prepare != vb->cnt_mem_finish ||
-				  vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
-				  vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
-				  vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
-				  vb->cnt_buf_queue != vb->cnt_buf_done ||
-				  vb->cnt_buf_prepare != vb->cnt_buf_finish ||
-				  vb->cnt_buf_init != vb->cnt_buf_cleanup;
-
-		if (unbalanced || debug) {
-			pr_info("   counters for queue %p, buffer %d:%s\n",
-				q, buffer, unbalanced ? " UNBALANCED!" : "");
-			pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
-				vb->cnt_buf_init, vb->cnt_buf_cleanup,
-				vb->cnt_buf_prepare, vb->cnt_buf_finish);
-			pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
-				vb->cnt_buf_out_validate, vb->cnt_buf_queue,
-				vb->cnt_buf_done, vb->cnt_buf_request_complete);
-			pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
-				vb->cnt_mem_alloc, vb->cnt_mem_put,
-				vb->cnt_mem_prepare, vb->cnt_mem_finish,
-				vb->cnt_mem_mmap);
-			pr_info("     get_userptr: %u put_userptr: %u\n",
-				vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
-			pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
-				vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
-				vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
-			pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
+	for (buffer = 0; buffer < vb2_get_num_buffers(q); buffer++) {
+		struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
+		bool unbalanced;
+
+		if (!vb)
+			continue;
+
+		unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
+			     vb->cnt_mem_prepare != vb->cnt_mem_finish ||
+			     vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
+			     vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
+			     vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
+			     vb->cnt_buf_queue != vb->cnt_buf_done ||
+			     vb->cnt_buf_prepare != vb->cnt_buf_finish ||
+			     vb->cnt_buf_init != vb->cnt_buf_cleanup;
+
+		if (unbalanced) {
+			pr_info("unbalanced counters for queue %p, buffer %d:\n",
+				q, buffer);
+			if (vb->cnt_buf_init != vb->cnt_buf_cleanup)
+				pr_info("     buf_init: %u buf_cleanup: %u\n",
+					vb->cnt_buf_init, vb->cnt_buf_cleanup);
+			if (vb->cnt_buf_prepare != vb->cnt_buf_finish)
+				pr_info("     buf_prepare: %u buf_finish: %u\n",
+					vb->cnt_buf_prepare, vb->cnt_buf_finish);
+			if (vb->cnt_buf_queue != vb->cnt_buf_done)
+				pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
+					vb->cnt_buf_out_validate, vb->cnt_buf_queue,
+					vb->cnt_buf_done, vb->cnt_buf_request_complete);
+			if (vb->cnt_mem_alloc != vb->cnt_mem_put)
+				pr_info("     alloc: %u put: %u\n",
+					vb->cnt_mem_alloc, vb->cnt_mem_put);
+			if (vb->cnt_mem_prepare != vb->cnt_mem_finish)
+				pr_info("     prepare: %u finish: %u\n",
+					vb->cnt_mem_prepare, vb->cnt_mem_finish);
+			if (vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr)
+				pr_info("     get_userptr: %u put_userptr: %u\n",
+					vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
+			if (vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf)
+				pr_info("     attach_dmabuf: %u detach_dmabuf: %u\n",
+					vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf);
+			if (vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf)
+				pr_info("     map_dmabuf: %u unmap_dmabuf: %u\n",
+					vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
+			pr_info("     get_dmabuf: %u num_users: %u\n",
 				vb->cnt_mem_get_dmabuf,
-				vb->cnt_mem_num_users,
-				vb->cnt_mem_vaddr,
-				vb->cnt_mem_cookie);
+				vb->cnt_mem_num_users);
 		}
 	}
 #endif
 
 	/* Free vb2 buffers */
-	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	for (buffer = q_num_buffers - buffers; buffer < q_num_buffers;
 	     ++buffer) {
-		kfree(q->bufs[buffer]);
-		q->bufs[buffer] = NULL;
+		struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
+
+		if (!vb)
+			continue;
+
+		vb2_queue_remove_buffer(vb);
+		kfree(vb);
 	}
 
 	q->num_buffers -= buffers;
-	if (!q->num_buffers) {
+	if (!vb2_get_num_buffers(q)) {
 		q->memory = VB2_MEMORY_UNKNOWN;
 		INIT_LIST_HEAD(&q->queued_list);
 	}
@@ -627,16 +691,21 @@ EXPORT_SYMBOL(vb2_buffer_in_use);
 static bool __buffers_in_use(struct vb2_queue *q)
 {
 	unsigned int buffer;
-	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
-		if (vb2_buffer_in_use(q, q->bufs[buffer]))
+	for (buffer = 0; buffer < vb2_get_num_buffers(q); ++buffer) {
+		struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
+
+		if (!vb)
+			continue;
+
+		if (vb2_buffer_in_use(q, vb))
 			return true;
 	}
 	return false;
 }
 
-void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
+void vb2_core_querybuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb)
 {
-	call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
+	call_void_bufop(q, fill_user_buffer, vb, pb);
 }
 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 
@@ -748,10 +817,11 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 		     unsigned int flags, unsigned int *count)
 {
 	unsigned int num_buffers, allocated_buffers, num_planes = 0;
+	unsigned int q_num_bufs = vb2_get_num_buffers(q);
 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
 	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 	unsigned int i;
-	int ret;
+	int ret = 0;
 
 	if (q->streaming) {
 		dprintk(q, 1, "streaming active\n");
@@ -763,7 +833,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 		return -EBUSY;
 	}
 
-	if (*count == 0 || q->num_buffers != 0 ||
+	if (*count == 0 || q_num_bufs != 0 ||
 	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
 	    !verify_coherency_flags(q, non_coherent_mem)) {
 		/*
@@ -781,7 +851,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 		 * queued without ever calling STREAMON.
 		 */
 		__vb2_queue_cancel(q);
-		__vb2_queue_free(q, q->num_buffers);
+		__vb2_queue_free(q, q_num_bufs);
 		mutex_unlock(&q->mmap_lock);
 
 		/*
@@ -795,17 +865,22 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 	/*
 	 * Make sure the requested values and current defaults are sane.
 	 */
-	WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
-	num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
-	num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
+	num_buffers = max_t(unsigned int, *count, q->min_queued_buffers);
+	num_buffers = min_t(unsigned int, num_buffers, q->max_num_buffers);
 	memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 	/*
 	 * Set this now to ensure that drivers see the correct q->memory value
 	 * in the queue_setup op.
 	 */
 	mutex_lock(&q->mmap_lock);
+	if (!q->bufs)
+		q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
+	if (!q->bufs)
+		ret = -ENOMEM;
 	q->memory = memory;
 	mutex_unlock(&q->mmap_lock);
+	if (ret)
+		return ret;
 	set_queue_coherency(q, non_coherent_mem);
 
 	/*
@@ -842,7 +917,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 	 * There is no point in continuing if we can't allocate the minimum
 	 * number of buffers needed by this vb2_queue.
 	 */
-	if (allocated_buffers < q->min_buffers_needed)
+	if (allocated_buffers < q->min_queued_buffers)
 		ret = -ENOMEM;
 
 	/*
@@ -876,7 +951,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 	if (ret < 0) {
 		/*
 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
-		 * from q->num_buffers and it will reset q->memory to
+		 * from already queued buffers and it will reset q->memory to
 		 * VB2_MEMORY_UNKNOWN.
 		 */
 		__vb2_queue_free(q, allocated_buffers);
@@ -910,10 +985,11 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 	unsigned int num_planes = 0, num_buffers, allocated_buffers;
 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
 	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
-	bool no_previous_buffers = !q->num_buffers;
-	int ret;
+	unsigned int q_num_bufs = vb2_get_num_buffers(q);
+	bool no_previous_buffers = !q_num_bufs;
+	int ret = 0;
 
-	if (q->num_buffers == VB2_MAX_FRAME) {
+	if (q->num_buffers == q->max_num_buffers) {
 		dprintk(q, 1, "maximum number of buffers already allocated\n");
 		return -ENOBUFS;
 	}
@@ -930,7 +1006,13 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 		 */
 		mutex_lock(&q->mmap_lock);
 		q->memory = memory;
+		if (!q->bufs)
+			q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
+		if (!q->bufs)
+			ret = -ENOMEM;
 		mutex_unlock(&q->mmap_lock);
+		if (ret)
+			return ret;
 		q->waiting_for_buffers = !q->is_output;
 		set_queue_coherency(q, non_coherent_mem);
 	} else {
@@ -942,7 +1024,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 			return -EINVAL;
 	}
 
-	num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
+	num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
 
 	if (requested_planes && requested_sizes) {
 		num_planes = requested_planes;
@@ -974,7 +1056,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 		num_buffers = allocated_buffers;
 
 		/*
-		 * q->num_buffers contains the total number of buffers, that the
+		 * num_buffers contains the total number of buffers, that the
 		 * queue driver has set up
 		 */
 		ret = call_qop(q, queue_setup, q, &num_buffers,
@@ -995,7 +1077,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 	if (ret < 0) {
 		/*
 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
-		 * from q->num_buffers and it will reset q->memory to
+		 * from already queued buffers and it will reset q->memory to
 		 * VB2_MEMORY_UNKNOWN.
 		 */
 		__vb2_queue_free(q, allocated_buffers);
@@ -1470,9 +1552,6 @@ static void vb2_req_unprepare(struct media_request_object *obj)
 	WARN_ON(!vb->req_obj.req);
 }
 
-int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
-		  struct media_request *req);
-
 static void vb2_req_queue(struct media_request_object *obj)
 {
 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
@@ -1487,7 +1566,7 @@ static void vb2_req_queue(struct media_request_object *obj)
 	 * set. We just ignore that, and expect this will be caught the
 	 * next time vb2_req_prepare() is called.
 	 */
-	err = vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
+	err = vb2_core_qbuf(vb->vb2_queue, vb, NULL, NULL);
 	WARN_ON_ONCE(err && err != -EIO);
 	mutex_unlock(vb->vb2_queue->lock);
 }
@@ -1542,12 +1621,10 @@ unsigned int vb2_request_buffer_cnt(struct media_request *req)
 }
 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
 
-int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
+int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb)
 {
-	struct vb2_buffer *vb;
 	int ret;
 
-	vb = q->bufs[index];
 	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
 		dprintk(q, 1, "invalid buffer state %s\n",
 			vb2_state_name(vb->state));
@@ -1576,7 +1653,7 @@ EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
  * @q:		videobuf2 queue
  *
  * Attempt to start streaming. When this function is called there must be
- * at least q->min_buffers_needed buffers queued up (i.e. the minimum
+ * at least q->min_queued_buffers queued up (i.e. the minimum
  * number of buffers required for the DMA engine to function). If the
  * @start_streaming op fails it is supposed to return all the driver-owned
  * buffers back to vb2 in state QUEUED. Check if that happened and if
@@ -1617,8 +1694,12 @@ static int vb2_start_streaming(struct vb2_queue *q)
 		 * Forcefully reclaim buffers if the driver did not
 		 * correctly return them to vb2.
 		 */
-		for (i = 0; i < q->num_buffers; ++i) {
-			vb = q->bufs[i];
+		for (i = 0; i < vb2_get_num_buffers(q); ++i) {
+			vb = vb2_get_buffer(q, i);
+
+			if (!vb)
+				continue;
+
 			if (vb->state == VB2_BUF_STATE_ACTIVE)
 				vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
 		}
@@ -1634,10 +1715,9 @@ static int vb2_start_streaming(struct vb2_queue *q)
 	return ret;
 }
 
-int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
+int vb2_core_qbuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb,
 		  struct media_request *req)
 {
-	struct vb2_buffer *vb;
 	enum vb2_buffer_state orig_state;
 	int ret;
 
@@ -1646,8 +1726,6 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
 		return -EIO;
 	}
 
-	vb = q->bufs[index];
-
 	if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
 	    q->requires_requests) {
 		dprintk(q, 1, "qbuf requires a request\n");
@@ -1768,7 +1846,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
 	 * then we can finally call start_streaming().
 	 */
 	if (q->streaming && !q->start_streaming_called &&
-	    q->queued_count >= q->min_buffers_needed) {
+	    q->queued_count >= q->min_queued_buffers) {
 		ret = vb2_start_streaming(q);
 		if (ret) {
 			/*
@@ -2022,12 +2100,18 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
 	 * to vb2 in stop_streaming().
 	 */
 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
-		for (i = 0; i < q->num_buffers; ++i)
-			if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
-				pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
-					q->bufs[i]);
-				vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
+		for (i = 0; i < vb2_get_num_buffers(q); i++) {
+			struct vb2_buffer *vb = vb2_get_buffer(q, i);
+
+			if (!vb)
+				continue;
+
+			if (vb->state == VB2_BUF_STATE_ACTIVE) {
+				pr_warn("driver bug: stop_streaming operation is leaving buffer %u in active state\n",
+					vb->index);
+				vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
 			}
+		}
 		/* Must be zero now */
 		WARN_ON(atomic_read(&q->owned_by_drv_count));
 	}
@@ -2060,10 +2144,15 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
 	 * call to __fill_user_buffer() after buf_finish(). That order can't
 	 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
 	 */
-	for (i = 0; i < q->num_buffers; ++i) {
-		struct vb2_buffer *vb = q->bufs[i];
-		struct media_request *req = vb->req_obj.req;
+	for (i = 0; i < vb2_get_num_buffers(q); i++) {
+		struct vb2_buffer *vb;
+		struct media_request *req;
+
+		vb = vb2_get_buffer(q, i);
+		if (!vb)
+			continue;
 
+		req = vb->req_obj.req;
 		/*
 		 * If a request is associated with this buffer, then
 		 * call buf_request_cancel() to give the driver to complete()
@@ -2103,6 +2192,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
 
 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
 {
+	unsigned int q_num_bufs = vb2_get_num_buffers(q);
 	int ret;
 
 	if (type != q->type) {
@@ -2115,14 +2205,14 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
 		return 0;
 	}
 
-	if (!q->num_buffers) {
+	if (!q_num_bufs) {
 		dprintk(q, 1, "no buffers have been allocated\n");
 		return -EINVAL;
 	}
 
-	if (q->num_buffers < q->min_buffers_needed) {
-		dprintk(q, 1, "need at least %u allocated buffers\n",
-				q->min_buffers_needed);
+	if (q_num_bufs < q->min_queued_buffers) {
+		dprintk(q, 1, "need at least %u queued buffers\n",
+			q->min_queued_buffers);
 		return -EINVAL;
 	}
 
@@ -2134,7 +2224,7 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
 	 * Tell driver to start streaming provided sufficient buffers
 	 * are available.
 	 */
-	if (q->queued_count >= q->min_buffers_needed) {
+	if (q->queued_count >= q->min_queued_buffers) {
 		ret = vb2_start_streaming(q);
 		if (ret)
 			goto unprepare;
@@ -2185,13 +2275,12 @@ int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
 
 /*
- * __find_plane_by_offset() - find plane associated with the given offset off
+ * __find_plane_by_offset() - find plane associated with the given offset
  */
-static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
-			unsigned int *_buffer, unsigned int *_plane)
+static int __find_plane_by_offset(struct vb2_queue *q, unsigned long offset,
+			struct vb2_buffer **vb, unsigned int *plane)
 {
-	struct vb2_buffer *vb;
-	unsigned int buffer, plane;
+	unsigned int buffer;
 
 	/*
 	 * Sanity checks to ensure the lock is held, MEMORY_MMAP is
@@ -2209,30 +2298,22 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
 		return -EBUSY;
 	}
 
-	/*
-	 * Go over all buffers and their planes, comparing the given offset
-	 * with an offset assigned to each plane. If a match is found,
-	 * return its buffer and plane numbers.
-	 */
-	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
-		vb = q->bufs[buffer];
+	/* Get buffer and plane from the offset */
+	buffer = (offset >> PLANE_INDEX_SHIFT) & BUFFER_INDEX_MASK;
+	*plane = (offset >> PAGE_SHIFT) & PLANE_INDEX_MASK;
 
-		for (plane = 0; plane < vb->num_planes; ++plane) {
-			if (vb->planes[plane].m.offset == off) {
-				*_buffer = buffer;
-				*_plane = plane;
-				return 0;
-			}
-		}
-	}
+	*vb = vb2_get_buffer(q, buffer);
+	if (!*vb)
+		return -EINVAL;
+	if (*plane >= (*vb)->num_planes)
+		return -EINVAL;
 
-	return -EINVAL;
+	return 0;
 }
 
 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
-		unsigned int index, unsigned int plane, unsigned int flags)
+		    struct vb2_buffer *vb, unsigned int plane, unsigned int flags)
 {
-	struct vb2_buffer *vb = NULL;
 	struct vb2_plane *vb_plane;
 	int ret;
 	struct dma_buf *dbuf;
@@ -2257,13 +2338,6 @@ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
 		return -EINVAL;
 	}
 
-	if (index >= q->num_buffers) {
-		dprintk(q, 1, "buffer index out of range\n");
-		return -EINVAL;
-	}
-
-	vb = q->bufs[index];
-
 	if (plane >= vb->num_planes) {
 		dprintk(q, 1, "buffer plane out of range\n");
 		return -EINVAL;
@@ -2282,20 +2356,20 @@ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
 			      flags & O_ACCMODE);
 	if (IS_ERR_OR_NULL(dbuf)) {
 		dprintk(q, 1, "failed to export buffer %d, plane %d\n",
-			index, plane);
+			vb->index, plane);
 		return -EINVAL;
 	}
 
 	ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
 	if (ret < 0) {
 		dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
-			index, plane, ret);
+			vb->index, plane, ret);
 		dma_buf_put(dbuf);
 		return ret;
 	}
 
 	dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
-		index, plane, ret);
+		vb->index, plane, ret);
 	*fd = ret;
 
 	return 0;
@@ -2304,9 +2378,9 @@ EXPORT_SYMBOL_GPL(vb2_core_expbuf);
 
 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
 {
-	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
+	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 	struct vb2_buffer *vb;
-	unsigned int buffer = 0, plane = 0;
+	unsigned int plane = 0;
 	int ret;
 	unsigned long length;
 
@@ -2335,12 +2409,10 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
 	 * Find the plane corresponding to the offset passed by userspace. This
 	 * will return an error if not MEMORY_MMAP or file I/O is in progress.
 	 */
-	ret = __find_plane_by_offset(q, off, &buffer, &plane);
+	ret = __find_plane_by_offset(q, offset, &vb, &plane);
 	if (ret)
 		goto unlock;
 
-	vb = q->bufs[buffer];
-
 	/*
 	 * MMAP requires page_aligned buffers.
 	 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
@@ -2368,7 +2440,7 @@ unlock:
 	if (ret)
 		return ret;
 
-	dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
+	dprintk(q, 3, "buffer %u, plane %d successfully mapped\n", vb->index, plane);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vb2_mmap);
@@ -2380,9 +2452,9 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
 				    unsigned long pgoff,
 				    unsigned long flags)
 {
-	unsigned long off = pgoff << PAGE_SHIFT;
+	unsigned long offset = pgoff << PAGE_SHIFT;
 	struct vb2_buffer *vb;
-	unsigned int buffer, plane;
+	unsigned int plane;
 	void *vaddr;
 	int ret;
 
@@ -2392,12 +2464,10 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
 	 * Find the plane corresponding to the offset passed by userspace. This
 	 * will return an error if not MEMORY_MMAP or file I/O is in progress.
 	 */
-	ret = __find_plane_by_offset(q, off, &buffer, &plane);
+	ret = __find_plane_by_offset(q, offset, &vb, &plane);
 	if (ret)
 		goto unlock;
 
-	vb = q->bufs[buffer];
-
 	vaddr = vb2_plane_vaddr(vb, plane);
 	mutex_unlock(&q->mmap_lock);
 	return vaddr ? (unsigned long)vaddr : -EINVAL;
@@ -2414,6 +2484,16 @@ int vb2_core_queue_init(struct vb2_queue *q)
 	/*
 	 * Sanity check
 	 */
+	/*
+	 * For drivers who don't support max_num_buffers ensure
+	 * a backward compatibility.
+	 */
+	if (!q->max_num_buffers)
+		q->max_num_buffers = VB2_MAX_FRAME;
+
+	/* The maximum is limited by offset cookie encoding pattern */
+	q->max_num_buffers = min_t(unsigned int, q->max_num_buffers, MAX_BUFFER_INDEX);
+
 	if (WARN_ON(!q)			  ||
 	    WARN_ON(!q->ops)		  ||
 	    WARN_ON(!q->mem_ops)	  ||
@@ -2423,18 +2503,22 @@ int vb2_core_queue_init(struct vb2_queue *q)
 	    WARN_ON(!q->ops->buf_queue))
 		return -EINVAL;
 
+	if (WARN_ON(q->max_num_buffers > MAX_BUFFER_INDEX) ||
+	    WARN_ON(q->min_queued_buffers > q->max_num_buffers))
+		return -EINVAL;
+
 	if (WARN_ON(q->requires_requests && !q->supports_requests))
 		return -EINVAL;
 
 	/*
 	 * This combination is not allowed since a non-zero value of
-	 * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
+	 * q->min_queued_buffers can cause vb2_core_qbuf() to fail if
 	 * it has to call start_streaming(), and the Request API expects
 	 * that queueing a request (and thus queueing a buffer contained
 	 * in that request) will always succeed. There is no method of
 	 * propagating an error back to userspace.
 	 */
-	if (WARN_ON(q->supports_requests && q->min_buffers_needed))
+	if (WARN_ON(q->supports_requests && q->min_queued_buffers))
 		return -EINVAL;
 
 	INIT_LIST_HEAD(&q->queued_list);
@@ -2468,7 +2552,9 @@ void vb2_core_queue_release(struct vb2_queue *q)
 	__vb2_cleanup_fileio(q);
 	__vb2_queue_cancel(q);
 	mutex_lock(&q->mmap_lock);
-	__vb2_queue_free(q, q->num_buffers);
+	__vb2_queue_free(q, vb2_get_num_buffers(q));
+	kfree(q->bufs);
+	q->bufs = NULL;
 	mutex_unlock(&q->mmap_lock);
 }
 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
@@ -2497,7 +2583,7 @@ __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
 	/*
 	 * Start file I/O emulator only if streaming API has not been used yet.
 	 */
-	if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
+	if (vb2_get_num_buffers(q) == 0 && !vb2_fileio_is_active(q)) {
 		if (!q->is_output && (q->io_modes & VB2_READ) &&
 				(req_events & (EPOLLIN | EPOLLRDNORM))) {
 			if (__vb2_init_fileio(q, 1))
@@ -2535,7 +2621,7 @@ __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
 	 * For output streams you can call write() as long as there are fewer
 	 * buffers queued than there are buffers available.
 	 */
-	if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
+	if (q->is_output && q->fileio && q->queued_count < vb2_get_num_buffers(q))
 		return EPOLLOUT | EPOLLWRNORM;
 
 	if (list_empty(&q->done_list)) {
@@ -2584,8 +2670,8 @@ struct vb2_fileio_buf {
  * struct vb2_fileio_data - queue context used by file io emulator
  *
  * @cur_index:	the index of the buffer currently being read from or
- *		written to. If equal to q->num_buffers then a new buffer
- *		must be dequeued.
+ *		written to. If equal to number of buffers in the vb2_queue
+ *		then a new buffer must be dequeued.
  * @initial_index: in the read() case all buffers are queued up immediately
  *		in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
  *		buffers. However, in the write() case no buffers are initially
@@ -2595,9 +2681,9 @@ struct vb2_fileio_buf {
  *		buffers. This means that initially __vb2_perform_fileio()
  *		needs to know what buffer index to use when it is queuing up
  *		the buffers for the first time. That initial index is stored
- *		in this field. Once it is equal to q->num_buffers all
- *		available buffers have been queued and __vb2_perform_fileio()
- *		should start the normal dequeue/queue cycle.
+ *		in this field. Once it is equal to number of buffers in the
+ *		vb2_queue all available buffers have been queued and
+ *		__vb2_perform_fileio() should start the normal dequeue/queue cycle.
  *
  * vb2 provides a compatibility layer and emulator of file io (read and
  * write) calls on top of streaming API. For proper operation it required
@@ -2625,6 +2711,7 @@ struct vb2_fileio_data {
 static int __vb2_init_fileio(struct vb2_queue *q, int read)
 {
 	struct vb2_fileio_data *fileio;
+	struct vb2_buffer *vb;
 	int i, ret;
 	unsigned int count = 0;
 
@@ -2644,13 +2731,18 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 	/*
 	 * Check if streaming api has not been already activated.
 	 */
-	if (q->streaming || q->num_buffers > 0)
+	if (q->streaming || vb2_get_num_buffers(q) > 0)
 		return -EBUSY;
 
 	/*
-	 * Start with count 1, driver can increase it in queue_setup()
+	 * Start with q->min_queued_buffers + 1, driver can increase it in
+	 * queue_setup()
+	 *
+	 * 'min_queued_buffers' buffers need to be queued up before you
+	 * can start streaming, plus 1 for userspace (or in this case,
+	 * kernelspace) processing.
 	 */
-	count = 1;
+	count = max(2, q->min_queued_buffers + 1);
 
 	dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
 		(read) ? "read" : "write", count, q->fileio_read_once,
@@ -2676,10 +2768,17 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 		goto err_kfree;
 
 	/*
+	 * Userspace can never add or delete buffers later, so there
+	 * will never be holes. It is safe to assume that vb2_get_buffer(q, 0)
+	 * will always return a valid vb pointer
+	 */
+	vb = vb2_get_buffer(q, 0);
+
+	/*
 	 * Check if plane_count is correct
 	 * (multiplane buffers are not supported).
 	 */
-	if (q->bufs[0]->num_planes != 1) {
+	if (vb->num_planes != 1) {
 		ret = -EBUSY;
 		goto err_reqbufs;
 	}
@@ -2687,13 +2786,16 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 	/*
 	 * Get kernel address of each buffer.
 	 */
-	for (i = 0; i < q->num_buffers; i++) {
-		fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
+	for (i = 0; i < vb2_get_num_buffers(q); i++) {
+		/* vb can never be NULL when using fileio. */
+		vb = vb2_get_buffer(q, i);
+
+		fileio->bufs[i].vaddr = vb2_plane_vaddr(vb, 0);
 		if (fileio->bufs[i].vaddr == NULL) {
 			ret = -EINVAL;
 			goto err_reqbufs;
 		}
-		fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
+		fileio->bufs[i].size = vb2_plane_size(vb, 0);
 	}
 
 	/*
@@ -2703,18 +2805,23 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 		/*
 		 * Queue all buffers.
 		 */
-		for (i = 0; i < q->num_buffers; i++) {
-			ret = vb2_core_qbuf(q, i, NULL, NULL);
+		for (i = 0; i < vb2_get_num_buffers(q); i++) {
+			struct vb2_buffer *vb2 = vb2_get_buffer(q, i);
+
+			if (!vb2)
+				continue;
+
+			ret = vb2_core_qbuf(q, vb2, NULL, NULL);
 			if (ret)
 				goto err_reqbufs;
 			fileio->bufs[i].queued = 1;
 		}
 		/*
 		 * All buffers have been queued, so mark that by setting
-		 * initial_index to q->num_buffers
+		 * initial_index to the number of buffers in the vb2_queue
 		 */
-		fileio->initial_index = q->num_buffers;
-		fileio->cur_index = q->num_buffers;
+		fileio->initial_index = vb2_get_num_buffers(q);
+		fileio->cur_index = fileio->initial_index;
 	}
 
 	/*
@@ -2807,7 +2914,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 	 * Check if we need to dequeue the buffer.
 	 */
 	index = fileio->cur_index;
-	if (index >= q->num_buffers) {
+	if (index >= vb2_get_num_buffers(q)) {
 		struct vb2_buffer *b;
 
 		/*
@@ -2821,15 +2928,17 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 
 		fileio->cur_index = index;
 		buf = &fileio->bufs[index];
-		b = q->bufs[index];
+
+		/* b can never be NULL when using fileio. */
+		b = vb2_get_buffer(q, index);
 
 		/*
 		 * Get number of bytes filled by the driver
 		 */
 		buf->pos = 0;
 		buf->queued = 0;
-		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
-				 : vb2_plane_size(q->bufs[index], 0);
+		buf->size = read ? vb2_get_plane_payload(b, 0)
+				 : vb2_plane_size(b, 0);
 		/* Compensate for data_offset on read in the multiplanar case. */
 		if (is_multiplanar && read &&
 				b->planes[0].data_offset < buf->size) {
@@ -2872,7 +2981,8 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 	 * Queue next buffer if required.
 	 */
 	if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
-		struct vb2_buffer *b = q->bufs[index];
+		/* b can never be NULL when using fileio. */
+		struct vb2_buffer *b = vb2_get_buffer(q, index);
 
 		/*
 		 * Check if this is the last buffer to read.
@@ -2889,7 +2999,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 
 		if (copy_timestamp)
 			b->timestamp = ktime_get_ns();
-		ret = vb2_core_qbuf(q, index, NULL, NULL);
+		ret = vb2_core_qbuf(q, b, NULL, NULL);
 		dprintk(q, 5, "vb2_qbuf result: %d\n", ret);
 		if (ret)
 			return ret;
@@ -2899,20 +3009,20 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 		 */
 		buf->pos = 0;
 		buf->queued = 1;
-		buf->size = vb2_plane_size(q->bufs[index], 0);
+		buf->size = vb2_plane_size(b, 0);
 		fileio->q_count += 1;
 		/*
 		 * If we are queuing up buffers for the first time, then
 		 * increase initial_index by one.
 		 */
-		if (fileio->initial_index < q->num_buffers)
+		if (fileio->initial_index < vb2_get_num_buffers(q))
 			fileio->initial_index++;
 		/*
 		 * The next buffer to use is either a buffer that's going to be
-		 * queued for the first time (initial_index < q->num_buffers)
-		 * or it is equal to q->num_buffers, meaning that the next
-		 * time we need to dequeue a buffer since we've now queued up
-		 * all the 'first time' buffers.
+		 * queued for the first time (initial_index < number of buffers in the vb2_queue)
+		 * or it is equal to the number of buffers in the vb2_queue,
+		 * meaning that the next time we need to dequeue a buffer since
+		 * we've now queued up all the 'first time' buffers.
 		 */
 		fileio->cur_index = fileio->initial_index;
 	}
@@ -2957,7 +3067,7 @@ static int vb2_thread(void *data)
 	int ret = 0;
 
 	if (q->is_output) {
-		prequeue = q->num_buffers;
+		prequeue = vb2_get_num_buffers(q);
 		copy_timestamp = q->copy_timestamp;
 	}
 
@@ -2970,7 +3080,9 @@ static int vb2_thread(void *data)
 		 * Call vb2_dqbuf to get buffer back.
 		 */
 		if (prequeue) {
-			vb = q->bufs[index++];
+			vb = vb2_get_buffer(q, index++);
+			if (!vb)
+				continue;
 			prequeue--;
 		} else {
 			call_void_qop(q, wait_finish, q);
@@ -2979,7 +3091,7 @@ static int vb2_thread(void *data)
 			call_void_qop(q, wait_prepare, q);
 			dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
 			if (!ret)
-				vb = q->bufs[index];
+				vb = vb2_get_buffer(q, index);
 		}
 		if (ret || threadio->stop)
 			break;
@@ -2992,7 +3104,7 @@ static int vb2_thread(void *data)
 		if (copy_timestamp)
 			vb->timestamp = ktime_get_ns();
 		if (!threadio->stop)
-			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
+			ret = vb2_core_qbuf(q, vb, NULL, NULL);
 		call_void_qop(q, wait_prepare, q);
 		if (ret || threadio->stop)
 			break;