change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/kernel/relay.c
..
..
@@ -1,7 +1,7 @@
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 /*
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  * Public API and common code for kernel->userspace relay file support.
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  *
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- * See Documentation/filesystems/relay.txt for an overview.
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+ * See Documentation/filesystems/relay.rst for an overview.
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  *
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  * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
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  * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
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@@ -91,7 +91,7 @@
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  *
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  *	Returns 0 if ok, negative on error
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  *
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- *	Caller should already have grabbed mmap_sem.
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+ *	Caller should already have grabbed mmap_lock.
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  */
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 static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
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 {
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@@ -163,13 +163,13 @@
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 {
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 	struct rchan_buf *buf;
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-	if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t *))
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+	if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t))
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 		return NULL;
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 	buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
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 	if (!buf)
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 		return NULL;
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-	buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t *),
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+	buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t),
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 				     GFP_KERNEL);
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 	if (!buf->padding)
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 		goto free_buf;
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@@ -997,14 +997,14 @@
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 /*
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  *	relay_file_read_avail - boolean, are there unconsumed bytes available?
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  */
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-static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
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+static int relay_file_read_avail(struct rchan_buf *buf)
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 {
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 	size_t subbuf_size = buf->chan->subbuf_size;
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 	size_t n_subbufs = buf->chan->n_subbufs;
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 	size_t produced = buf->subbufs_produced;
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-	size_t consumed = buf->subbufs_consumed;
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+	size_t consumed;
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-	relay_file_read_consume(buf, read_pos, 0);
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+	relay_file_read_consume(buf, 0, 0);
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 	consumed = buf->subbufs_consumed;
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@@ -1065,23 +1065,21 @@
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 /**
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  *	relay_file_read_start_pos - find the first available byte to read
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- *	@read_pos: file read position
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  *	@buf: relay channel buffer
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  *
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- *	If the @read_pos is in the middle of padding, return the
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+ *	If the read_pos is in the middle of padding, return the
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  *	position of the first actually available byte, otherwise
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  *	return the original value.
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  */
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-static size_t relay_file_read_start_pos(size_t read_pos,
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-					struct rchan_buf *buf)
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+static size_t relay_file_read_start_pos(struct rchan_buf *buf)
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 {
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 	size_t read_subbuf, padding, padding_start, padding_end;
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 	size_t subbuf_size = buf->chan->subbuf_size;
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 	size_t n_subbufs = buf->chan->n_subbufs;
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 	size_t consumed = buf->subbufs_consumed % n_subbufs;
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+	size_t read_pos = (consumed * subbuf_size + buf->bytes_consumed)
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+			% (n_subbufs * subbuf_size);
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-	if (!read_pos)
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-		read_pos = consumed * subbuf_size + buf->bytes_consumed;
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 	read_subbuf = read_pos / subbuf_size;
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 	padding = buf->padding[read_subbuf];
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 	padding_start = (read_subbuf + 1) * subbuf_size - padding;
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@@ -1137,10 +1135,10 @@
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 	do {
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 		void *from;
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-		if (!relay_file_read_avail(buf, *ppos))
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+		if (!relay_file_read_avail(buf))
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 			break;
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-		read_start = relay_file_read_start_pos(*ppos, buf);
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+		read_start = relay_file_read_start_pos(buf);
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 		avail = relay_file_read_subbuf_avail(read_start, buf);
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 		if (!avail)
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 			break;
..
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@@ -1183,11 +1181,9 @@
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 }
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 static const struct pipe_buf_operations relay_pipe_buf_ops = {
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-	.can_merge = 0,
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-	.confirm = generic_pipe_buf_confirm,
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-	.release = relay_pipe_buf_release,
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-	.steal = generic_pipe_buf_steal,
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-	.get = generic_pipe_buf_get,
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+	.release	= relay_pipe_buf_release,
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+	.try_steal	= generic_pipe_buf_try_steal,
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+	.get		= generic_pipe_buf_get,
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 };
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 static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)