Merge tag 'io_uring-6.6-2023-10-27' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe: "Fix for an issue reported where reading fdinfo could find a NULL thread as we didn't properly synchronize, and then a disable for the IOCB_DIO_CALLER_COMP optimization as a recent reported highlighted how that could lead to deadlocks if the task issued async O_DIRECT writes and then proceeded to do sync fallocate() calls" * tag 'io_uring-6.6-2023-10-27' of git://git.kernel.dk/linux: io_uring/rw: disable IOCB_DIO_CALLER_COMP io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid

Linus Torvalds committed 3 years ago

Commit 56567a22 parents 2dc4e0f 838b35b2 files · +12 −15Browse files

Unified · Split

2 files

io_uring/fdinfo.c +12 −6
io_uring/rw.c +0 −9

io_uring/fdinfo.c+12−6

@@ -53,7 +53,6 @@ static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id, · 52 unmodified lines
53	__cold void io_uring_show_fdinfo(struct seq_file m, struct file f)	53	__cold void io_uring_show_fdinfo(struct seq_file m, struct file f)
54	{	54	{
55	struct io_ring_ctx *ctx = f->private_data;	55	struct io_ring_ctx *ctx = f->private_data;
56	struct io_sq_data *sq = NULL;
57	struct io_overflow_cqe *ocqe;	56	struct io_overflow_cqe *ocqe;
58	struct io_rings *r = ctx->rings;	57	struct io_rings *r = ctx->rings;
59	unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;	58	unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
@@ -64,6 +63,7 @@ __cold void io_uring_show_fdinfo(struct seq_file m, struct file f) · 4 unmodified lines
64	unsigned int cq_shift = 0;	63	unsigned int cq_shift = 0;
65	unsigned int sq_shift = 0;	64	unsigned int sq_shift = 0;
66	unsigned int sq_entries, cq_entries;	65	unsigned int sq_entries, cq_entries;
		66	int sq_pid = -1, sq_cpu = -1;
67	bool has_lock;	67	bool has_lock;
68	unsigned int i;	68	unsigned int i;
69		69
@@ -143,13 +143,19 @@ __cold void io_uring_show_fdinfo(struct seq_file m, struct file f) · 73 unmodified lines
143	has_lock = mutex_trylock(&ctx->uring_lock);	143	has_lock = mutex_trylock(&ctx->uring_lock);
144		144
145	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {	145	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
146	sq = ctx->sq_data;	146	struct io_sq_data *sq = ctx->sq_data;
147	if (!sq->thread)	147
148	sq = NULL;	148	if (mutex_trylock(&sq->lock)) {
		149	if (sq->thread) {
		150	sq_pid = task_pid_nr(sq->thread);
		151	sq_cpu = task_cpu(sq->thread);
		152	}
		153	mutex_unlock(&sq->lock);
		154	}
149	}	155	}
150		156
151	seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);	157	seq_printf(m, "SqThread:\t%d\n", sq_pid);
152	seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);	158	seq_printf(m, "SqThreadCpu:\t%d\n", sq_cpu);
153	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);	159	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
154	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {	160	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
155	struct file *f = io_file_from_index(&ctx->file_table, i);	161	struct file *f = io_file_from_index(&ctx->file_table, i);

io_uring/rw.c+0−9

@@ -913,15 +913,6 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) · 912 unmodified lines
913	kiocb_start_write(kiocb);	913	kiocb_start_write(kiocb);
914	kiocb->ki_flags \|= IOCB_WRITE;	914	kiocb->ki_flags \|= IOCB_WRITE;
915		915
916	/*
917	* For non-polled IO, set IOCB_DIO_CALLER_COMP, stating that our handler
918	* groks deferring the completion to task context. This isn't
919	* necessary and useful for polled IO as that can always complete
920	* directly.
921	*/
922	if (!(kiocb->ki_flags & IOCB_HIPRI))
923	kiocb->ki_flags \|= IOCB_DIO_CALLER_COMP;
924
925	if (likely(req->file->f_op->write_iter))	916	if (likely(req->file->f_op->write_iter))
926	ret2 = call_write_iter(req->file, kiocb, &s->iter);	917	ret2 = call_write_iter(req->file, kiocb, &s->iter);
927	else if (req->file->f_op->write)	918	else if (req->file->f_op->write)