Since I butchered this I figured better to make sure we have testcases for this now. Since we only have a locking context for __GFP_FS that's the only thing we're testing right now.
Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Cc: Dave Chinner <[email protected]> Cc: Qian Cai <[email protected]> Cc: [email protected] Cc: Thomas Hellström (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Maarten Lankhorst <[email protected]> Cc: Christian König <[email protected]> Cc: "Matthew Wilcox (Oracle)" <[email protected]> Signed-off-by: Daniel Vetter <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] --- lib/locking-selftest.c | 47 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index a899b3f0e2e5..ad47c3358e30 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -15,6 +15,7 @@ #include <linux/mutex.h> #include <linux/ww_mutex.h> #include <linux/sched.h> +#include <linux/sched/mm.h> #include <linux/delay.h> #include <linux/lockdep.h> #include <linux/spinlock.h> @@ -2357,6 +2358,50 @@ static void queued_read_lock_tests(void) pr_cont("\n"); } +static void fs_reclaim_correct_nesting(void) +{ + fs_reclaim_acquire(GFP_KERNEL); + might_alloc(GFP_NOFS); + fs_reclaim_release(GFP_KERNEL); +} + +static void fs_reclaim_wrong_nesting(void) +{ + fs_reclaim_acquire(GFP_KERNEL); + might_alloc(GFP_KERNEL); + fs_reclaim_release(GFP_KERNEL); +} + +static void fs_reclaim_protected_nesting(void) +{ + unsigned int flags; + + fs_reclaim_acquire(GFP_KERNEL); + flags = memalloc_nofs_save(); + might_alloc(GFP_KERNEL); + memalloc_nofs_restore(flags); + fs_reclaim_release(GFP_KERNEL); +} + +static void fs_reclaim_tests(void) +{ + printk(" --------------------\n"); + printk(" | fs_reclaim tests |\n"); + printk(" --------------------\n"); + + print_testname("correct nesting"); + dotest(fs_reclaim_correct_nesting, SUCCESS, 0); + pr_cont("\n"); + + print_testname("wrong nesting"); + dotest(fs_reclaim_wrong_nesting, FAILURE, 0); + pr_cont("\n"); + + print_testname("protected nesting"); + dotest(fs_reclaim_protected_nesting, SUCCESS, 0); + pr_cont("\n"); +} + void locking_selftest(void) { /* @@ -2478,6 +2523,8 @@ void locking_selftest(void) if (IS_ENABLED(CONFIG_QUEUED_RWLOCKS)) queued_read_lock_tests(); + fs_reclaim_tests(); + if (unexpected_testcase_failures) { printk("-----------------------------------------------------------------\n"); debug_locks = 0; -- 2.29.2
