From a7c2242166eb4b4447b0145705e4b66f5be89798 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 25 Sep 2016 22:52:02 -0400 Subject: [PATCH] relay: simplify relay_file_read() to hell with actors... Signed-off-by: Al Viro --- kernel/relay.c | 78 +++++++++++++++------------------------------------------- 1 file changed, 20 insertions(+), 58 deletions(-) diff --git a/kernel/relay.c b/kernel/relay.c index d797502..6fa398e 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -1121,51 +1121,23 @@ static size_t relay_file_read_end_pos(struct rchan_buf *buf, return end_pos; } -/* - * subbuf_read_actor - read up to one subbuf's worth of data - */ -static int subbuf_read_actor(size_t read_start, - struct rchan_buf *buf, - size_t avail, - read_descriptor_t *desc) -{ - void *from; - int ret = 0; - - from = buf->start + read_start; - ret = avail; - if (copy_to_user(desc->arg.buf, from, avail)) { - desc->error = -EFAULT; - ret = 0; - } - desc->arg.data += ret; - desc->written += ret; - desc->count -= ret; - - return ret; -} - -typedef int (*subbuf_actor_t) (size_t read_start, - struct rchan_buf *buf, - size_t avail, - read_descriptor_t *desc); - -/* - * relay_file_read_subbufs - read count bytes, bridging subbuf boundaries - */ -static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, - subbuf_actor_t subbuf_actor, - read_descriptor_t *desc) +static ssize_t relay_file_read(struct file *filp, + char __user *buffer, + size_t count, + loff_t *ppos) { struct rchan_buf *buf = filp->private_data; size_t read_start, avail; + size_t written = 0; int ret; - if (!desc->count) + if (!count) return 0; inode_lock(file_inode(filp)); do { + void *from; + if (!relay_file_read_avail(buf, *ppos)) break; @@ -1174,32 +1146,22 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, if (!avail) break; - avail = min(desc->count, avail); - ret = subbuf_actor(read_start, buf, avail, desc); - if (desc->error < 0) + avail = min(count, avail); + from = buf->start + read_start; + ret = avail; + if (copy_to_user(buffer, from, avail)) break; - if (ret) { - relay_file_read_consume(buf, read_start, ret); - *ppos = relay_file_read_end_pos(buf, read_start, ret); - } - } while (desc->count && ret); - inode_unlock(file_inode(filp)); + buffer += ret; + written += ret; + count -= ret; - return desc->written; -} + relay_file_read_consume(buf, read_start, ret); + *ppos = relay_file_read_end_pos(buf, read_start, ret); + } while (count); + inode_unlock(file_inode(filp)); -static ssize_t relay_file_read(struct file *filp, - char __user *buffer, - size_t count, - loff_t *ppos) -{ - read_descriptor_t desc; - desc.written = 0; - desc.count = count; - desc.arg.buf = buffer; - desc.error = 0; - return relay_file_read_subbufs(filp, ppos, subbuf_read_actor, &desc); + return written; } static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed) -- 2.7.4