linux-kernel - [PATCH printk v2 13/26] printk: Add @flags argument for console_is

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Date: Sun, 18 Feb 2024 20:03:13 +0106
From: John Ogness <john.ogness@...utronix.de>
To: Petr Mladek <pmladek@...e.com>
Cc: Sergey Senozhatsky <senozhatsky@...omium.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-kernel@...r.kernel.org
Subject: [PATCH printk v2 13/26] printk: Add @flags argument for console_is_usable()

The caller of console_is_usable() usually needs @console->flags
for its own checks. Rather than having console_is_usable() read
its own copy, make the caller pass in the @flags. This also
ensures that the caller saw the same @flags value.

Signed-off-by: John Ogness <john.ogness@...utronix.de>
Reviewed-by: Petr Mladek <pmladek@...e.com>
---
 kernel/printk/internal.h | 8 ++------
 kernel/printk/printk.c   | 5 +++--
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index 69c8861be92c..6780911fa8f2 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -83,13 +83,9 @@ void nbcon_free(struct console *con);
  * records. Note that this function does not consider the current context,
  * which can also play a role in deciding if @con can be used to print
  * records.
- *
- * Requires the console_srcu_read_lock.
  */
-static inline bool console_is_usable(struct console *con)
+static inline bool console_is_usable(struct console *con, short flags)
 {
-	short flags = console_srcu_read_flags(con);
-
 	if (!(flags & CON_ENABLED))
 		return false;
 
@@ -136,7 +132,7 @@ static inline bool nbcon_alloc(struct console *con) { return false; }
 static inline void nbcon_init(struct console *con) { }
 static inline void nbcon_free(struct console *con) { }
 
-static inline bool console_is_usable(struct console *con) { return false; }
+static inline bool console_is_usable(struct console *con, short flags) { return false; }
 
 #endif /* CONFIG_PRINTK */
 
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index ecb50590815c..9d56ce5837f9 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2939,9 +2939,10 @@ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handove
 
 		cookie = console_srcu_read_lock();
 		for_each_console_srcu(con) {
+			short flags = console_srcu_read_flags(con);
 			bool progress;
 
-			if (!console_is_usable(con))
+			if (!console_is_usable(con, flags))
 				continue;
 			any_usable = true;
 
@@ -3783,7 +3784,7 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre
 			 * that they make forward progress, so only increment
 			 * @diff for usable consoles.
 			 */
-			if (!console_is_usable(c))
+			if (!console_is_usable(c, flags))
 				continue;
 
 			if (flags & CON_NBCON) {
-- 
2.39.2