From fd80d14005250652e7500a97eedd68797de0b797 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Wed, 10 Jul 2024 12:59:28 -0400
Subject: [PATCH] bcachefs: fix scheduling while atomic in break_cycle()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
fs/bcachefs/btree_locking.c | 2 +-
fs/bcachefs/util.c | 25 ++++++++++++++++++++++---
fs/bcachefs/util.h | 1 +
3 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c
index d66fff22109ae..191d9a50378aa 100644
--- a/fs/bcachefs/btree_locking.c
+++ b/fs/bcachefs/btree_locking.c
@@ -231,7 +231,7 @@ static noinline int break_cycle(struct lock_graph *g, struct printbuf *cycle)
prt_newline(&buf);
}
- bch2_print_string_as_lines(KERN_ERR, buf.buf);
+ bch2_print_string_as_lines_nonblocking(KERN_ERR, buf.buf);
printbuf_exit(&buf);
BUG();
}
diff --git a/fs/bcachefs/util.c b/fs/bcachefs/util.c
index de331dec2a99c..4ec7e44d6e36c 100644
--- a/fs/bcachefs/util.c
+++ b/fs/bcachefs/util.c
@@ -252,8 +252,10 @@ void bch2_prt_u64_base2(struct printbuf *out, u64 v)
bch2_prt_u64_base2_nbits(out, v, fls64(v) ?: 1);
}
-void bch2_print_string_as_lines(const char *prefix, const char *lines)
+static void __bch2_print_string_as_lines(const char *prefix, const char *lines,
+ bool nonblocking)
{
+ bool locked = false;
const char *p;
if (!lines) {
@@ -261,7 +263,13 @@ void bch2_print_string_as_lines(const char *prefix, const char *lines)
return;
}
- console_lock();
+ if (!nonblocking) {
+ console_lock();
+ locked = true;
+ } else {
+ locked = console_trylock();
+ }
+
while (1) {
p = strchrnul(lines, '\n');
printk("%s%.*s\n", prefix, (int) (p - lines), lines);
@@ -269,7 +277,18 @@ void bch2_print_string_as_lines(const char *prefix, const char *lines)
break;
lines = p + 1;
}
- console_unlock();
+ if (locked)
+ console_unlock();
+}
+
+void bch2_print_string_as_lines(const char *prefix, const char *lines)
+{
+ return __bch2_print_string_as_lines(prefix, lines, false);
+}
+
+void bch2_print_string_as_lines_nonblocking(const char *prefix, const char *lines)
+{
+ return __bch2_print_string_as_lines(prefix, lines, true);
}
int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *task, unsigned skipnr,
diff --git a/fs/bcachefs/util.h b/fs/bcachefs/util.h
index 5d2c470a49ac9..5b0533ec4c7e1 100644
--- a/fs/bcachefs/util.h
+++ b/fs/bcachefs/util.h
@@ -315,6 +315,7 @@ 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 *prefix, const char *lines);
+void bch2_print_string_as_lines_nonblocking(const char *prefix, const char *lines);
typedef DARRAY(unsigned long) bch_stacktrace;
int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *, unsigned, gfp_t);
--
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