vb2_read(9)

💖 vb2_read — Kernel API Manual 💖

okay so bestie, welcome to the vb2_read page from the Kernel API Manual. This is the function that implements read() syscall logic, and we’re gonna get you comfy with it, no cap. ✨

✨ NAME ✨

vb2_read — implements read() syscall logic. periodt. 💅

🦋 SYNOPSIS 🦋

ssize_t vb2_read (struct vb2_queue *q , char __user *data , size_t count
, loff_t *ppos , int nonblock );

🌸 ARGUMENTS 🌸

• q — a pointer to your struct vb2_queue with the videobuf2 queue. This is the queue bestie in question. 👑
• data — points to the target userspace buffer. that’s where the data is headed, iykyk. 💫
• count — number of bytes to read. literally the byte count, bestie. 🍓
• ppos — file handle position tracking pointer. it’s the little tracker keeping up with the file handle position. 🎀
• nonblock — mode selector: 1 means blocking calls, 0 means nonblocking. yes, that’s exactly how the page says it — I’m not editing the spec, bestie. 😭

👀 SEE ALSO 👀

Kernel file ./include/media/videobuf2-core.h — here’s the whole squad, in order:

• enum vb2_memory(9)
• struct vb2_mem_ops(9)
• struct vb2_plane(9)
• enum vb2_io_modes(9)
• enum vb2_buffer_state(9)
• struct vb2_buffer(9)
• struct vb2_ops(9)
• struct vb2_buf_ops(9)
• struct vb2_queue(9)
• vb2_queue_allows_cache_hints(9)
• vb2_plane_vaddr(9)
• vb2_plane_cookie(9)
• vb2_buffer_done(9)
• vb2_discard_done(9)
• vb2_wait_for_all_buffers(9)
• vb2_core_querybuf(9)
• vb2_core_reqbufs(9)
• vb2_core_create_bufs(9)
• vb2_core_prepare_buf(9)
• vb2_core_remove_bufs(9)
• vb2_core_qbuf(9)
• vb2_core_dqbuf(9)
• vb2_core_streamon(9)
• vb2_core_streamoff(9)
• vb2_core_expbuf(9)
• vb2_core_queue_init(9)
• vb2_core_queue_release(9)
• vb2_queue_error(9)
• vb2_mmap(9)
• vb2_get_unmapped_area(9)
• vb2_core_poll(9)
• vb2_write(9)
• vb2_thread_fnc(9)
• vb2_thread_start(9)
• vb2_thread_stop(9)
• vb2_is_streaming(9)
• vb2_fileio_is_active(9)
• vb2_get_num_buffers(9)
• vb2_is_busy(9)
• vb2_get_drv_priv(9)
• vb2_set_plane_payload(9)
• vb2_get_plane_payload(9)
• vb2_plane_size(9)
• vb2_start_streaming_called(9)
• vb2_clear_last_buffer_dequeued(9)
• vb2_get_buffer(9)
• vb2_buffer_in_use(9)
• vb2_verify_memory_type(9)
• vb2_request_object_is_buffer(9)
• vb2_request_buffer_cnt(9)

🫶 that’s the whole page, bestie — source/version: ./include/media · date: October 2026 · manual: vb2_read(9) · bye! 💖💅