diff options
| -rw-r--r-- | include/uapi/linux/io_uring.h | 3 | ||||
| -rw-r--r-- | io_uring/kbuf.c | 8 | ||||
| -rw-r--r-- | io_uring/kbuf.h | 7 |
3 files changed, 16 insertions, 2 deletions
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 17ac1b785440..909fb7aea638 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -905,7 +905,8 @@ struct io_uring_buf_reg { __u32 ring_entries; __u16 bgid; __u16 flags; - __u64 resv[3]; + __u32 min_left; + __u32 resv[5]; }; /* argument for IORING_REGISTER_PBUF_STATUS */ diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 43e4f8615fe8..63061aa1cab9 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -47,7 +47,7 @@ static bool io_kbuf_inc_commit(struct io_buffer_list *bl, int len) this_len = min_t(u32, len, buf_len); buf_len -= this_len; /* Stop looping for invalid buffer length of 0 */ - if (buf_len || !this_len) { + if (buf_len > bl->min_left_sub_one || !this_len) { WRITE_ONCE(buf->addr, READ_ONCE(buf->addr) + this_len); WRITE_ONCE(buf->len, buf_len); return false; @@ -637,6 +637,10 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) if (reg.ring_entries >= 65536) return -EINVAL; + /* minimum left byte count is a property of incremental buffers */ + if (!(reg.flags & IOU_PBUF_RING_INC) && reg.min_left) + return -EINVAL; + bl = io_buffer_get_list(ctx, reg.bgid); if (bl) { /* if mapped buffer ring OR classic exists, don't allow */ @@ -683,6 +687,8 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) bl->mask = reg.ring_entries - 1; bl->flags |= IOBL_BUF_RING; bl->buf_ring = br; + if (reg.min_left) + bl->min_left_sub_one = reg.min_left - 1; if (reg.flags & IOU_PBUF_RING_INC) bl->flags |= IOBL_INC; ret = io_buffer_add_list(ctx, bl, reg.bgid); diff --git a/io_uring/kbuf.h b/io_uring/kbuf.h index abf7052b556e..401773e1ef80 100644 --- a/io_uring/kbuf.h +++ b/io_uring/kbuf.h @@ -32,6 +32,13 @@ struct io_buffer_list { __u16 flags; + /* + * minimum required amount to be left to reuse an incrementally + * consumed buffer. If less than this is left at consumption time, + * buffer is done and head is incremented to the next buffer. + */ + __u32 min_left_sub_one; + struct io_mapped_region region; }; |