bcachefs: Fix possible console lock involved deadlock

Link: https://lore.kernel.org/all/[email protected]/T/
Reported-by: [email protected]
Signed-off-by: Alan Huang <[email protected]>
Signed-off-by: Kent Overstreet <[email protected]>

Author: alanskind

fs/bcachefs/bcachefs.h

@@ -296,7 +296,6 @@ do {									\
 #define bch2_fmt(_c, fmt)		bch2_log_msg(_c, fmt "\n")
 
 void bch2_print_str(struct bch_fs *, const char *, const char *);
-void bch2_print_str_nonblocking(struct bch_fs *, const char *, const char *);
 
 __printf(2, 3)
 void bch2_print_opts(struct bch_opts *, const char *, ...);

fs/bcachefs/btree_locking.c

@@ -213,7 +213,7 @@ static noinline __noreturn void break_cycle_fail(struct lock_graph *g)
 		prt_newline(&buf);
 	}
 
-	bch2_print_str_nonblocking(g->g->trans->c, KERN_ERR, buf.buf);
+	bch2_print_str(g->g->trans->c, KERN_ERR, buf.buf);
 	printbuf_exit(&buf);
 	BUG();
 }

fs/bcachefs/error.c

@@ -69,7 +69,7 @@ static bool bch2_fs_trans_inconsistent(struct bch_fs *c, struct btree_trans *tra
 	if (trans)
 		bch2_trans_updates_to_text(&buf, trans);
 	bool ret = __bch2_inconsistent_error(c, &buf);
-	bch2_print_str_nonblocking(c, KERN_ERR, buf.buf);
+	bch2_print_str(c, KERN_ERR, buf.buf);
 
 	printbuf_exit(&buf);
 	return ret;

fs/bcachefs/super.c

@@ -104,7 +104,7 @@ const char * const bch2_dev_write_refs[] = {
 #undef x
 
 static void __bch2_print_str(struct bch_fs *c, const char *prefix,
-			     const char *str, bool nonblocking)
+			     const char *str)
 {
 #ifdef __KERNEL__
 	struct stdio_redirect *stdio = bch2_fs_stdio_redirect(c);
@@ -114,17 +114,12 @@ static void __bch2_print_str(struct bch_fs *c, const char *prefix,
 		return;
 	}
 #endif
-	bch2_print_string_as_lines(KERN_ERR, str, nonblocking);
+	bch2_print_string_as_lines(KERN_ERR, str);
 }
 
 void bch2_print_str(struct bch_fs *c, const char *prefix, const char *str)
 {
-	__bch2_print_str(c, prefix, str, false);
-}
-
-void bch2_print_str_nonblocking(struct bch_fs *c, const char *prefix, const char *str)
-{
-	__bch2_print_str(c, prefix, str, true);
+	__bch2_print_str(c, prefix, str);
 }
 
 __printf(2, 0)

fs/bcachefs/util.c

@@ -262,8 +262,7 @@ static bool string_is_spaces(const char *str)
 	return true;
 }
 
-void bch2_print_string_as_lines(const char *prefix, const char *lines,
-				bool nonblocking)
+void bch2_print_string_as_lines(const char *prefix, const char *lines)
 {
 	bool locked = false;
 	const char *p;
@@ -273,12 +272,7 @@ void bch2_print_string_as_lines(const char *prefix, const char *lines,
 		return;
 	}
 
-	if (!nonblocking) {
-		console_lock();
-		locked = true;
-	} else {
-		locked = console_trylock();
-	}
+	locked = console_trylock();
 
 	while (*lines) {
 		p = strchrnul(lines, '\n');

fs/bcachefs/util.h

@@ -214,7 +214,7 @@ u64 bch2_read_flag_list(const char *, const char * const[]);
 void bch2_prt_u64_base2_nbits(struct printbuf *, u64, unsigned);
 void bch2_prt_u64_base2(struct printbuf *, u64);
 
-void bch2_print_string_as_lines(const char *, const char *, bool);
+void bch2_print_string_as_lines(const char *, const char *);
 
 typedef DARRAY(unsigned long) bch_stacktrace;
 int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *, unsigned, gfp_t);