kernel/linux.git/drivers/net/netconsole.c, branch v6.13.6

net: netconsole: split send_msg_fragmented

2024-10-22T13:44:25+00:00

Refactor the send_msg_fragmented() function by extracting the logic for sending the message body into a new function called send_fragmented_body(). Now, send_msg_fragmented() handles appending the release and header, and then delegates the task of breaking up the body and sending the fragments to send_fragmented_body(). This is the final flow now: When send_ext_msg_udp() is called to send a message, it will: - call send_msg_no_fragmentation() if no fragmentation is needed or - call send_msg_fragmented() if fragmentation is needed * send_msg_fragmented() appends the header to the buffer, which is be persisted until the function returns * call send_fragmented_body() to iterate and populate the body of the message. It will not touch the header, and it will only replace the body, writing the msgbody and/or userdata. Also add some comment to make the code easier to review. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: do not pass userdata up to the tail

2024-10-22T13:44:25+00:00

Do not pass userdata to send_msg_fragmented, since we can get it later. This will be more useful in the next patch, where send_msg_fragmented() will be split even more, and userdata is only necessary in the last function. Suggested-by: Simon Horman Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: extract release appending into separate function

2024-10-22T13:44:25+00:00

Refactor the code by extracting the logic for appending the release into the buffer into a separate function. The goal is to reduce the size of send_msg_fragmented() and improve code readability. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: track explicitly if msgbody was written to buffer

2024-10-22T13:44:25+00:00

The current check to determine if the message body was fully sent is difficult to follow. To improve clarity, introduce a variable that explicitly tracks whether the message body (msgbody) has been completely sent, indicating when it's time to begin sending userdata. Additionally, add comments to make the code more understandable for others who may work with it. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: introduce variable to track body length

2024-10-22T13:44:24+00:00

This new variable tracks the total length of the data to be sent, encompassing both the message body (msgbody) and userdata, which is collectively called body. By explicitly defining body_len, the code becomes clearer and easier to reason about, simplifying offset calculations and improving overall readability of the function. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: rename body to msg_body

2024-10-22T13:44:24+00:00

With the introduction of the userdata concept, the term body has become ambiguous and less intuitive. To improve clarity, body is renamed to msg_body, making it clear that the body is not the only content following the header. In an upcoming patch, the term body_len will also be revised for further clarity. The current packet structure is as follows: release, header, body, [msg_body + userdata] Here, [msg_body + userdata] collectively forms what is currently referred to as "body." This renaming helps to distinguish and better understand each component of the packet. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: separate fragmented message handling in send_ext_msg

2024-10-22T13:44:24+00:00

Following the previous change, where the non-fragmented case was moved to its own function, this update introduces a new function called send_msg_fragmented to specifically manage scenarios where message fragmentation is required. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: split send_ext_msg_udp() function

2024-10-22T13:44:24+00:00

The send_ext_msg_udp() function has become quite large, currently spanning 102 lines. Its complexity, along with extensive pointer and offset manipulation, makes it difficult to read and error-prone. The function has evolved over time, and it’s now due for a refactor. To improve readability and maintainability, isolate the case where no message fragmentation occurs into a separate function, into a new send_msg_no_fragmentation() function. This scenario covers about 95% of the messages. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: remove msg_ready variable

2024-10-22T13:44:24+00:00

Variable msg_ready is useless, since it does not represent anything. Get rid of it, using buf directly instead. Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

net: netconsole: fix wrong warning

2024-10-10T02:42:43+00:00

A warning is triggered when there is insufficient space in the buffer for userdata. However, this is not an issue since userdata will be sent in the next iteration. Current warning message: ------------[ cut here ]------------ WARNING: CPU: 13 PID: 3013042 at drivers/net/netconsole.c:1122 write_ext_msg+0x3b6/0x3d0 ? write_ext_msg+0x3b6/0x3d0 console_flush_all+0x1e9/0x330 The code incorrectly issues a warning when this_chunk is zero, which is a valid scenario. The warning should only be triggered when this_chunk is negative. Fixes: 1ec9daf95093 ("net: netconsole: append userdata to fragmented netconsole messages") Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Link: https://patch.msgid.link/20241008094325.896208-1-leitao@debian.org Signed-off-by: Jakub Kicinski