Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+12
-15
+12
-6
io_uring/fdinfo.c
+12
-6
io_uring/fdinfo.c
···
53
53
__cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
54
54
{
55
55
struct io_ring_ctx *ctx = f->private_data;
56
-
struct io_sq_data *sq = NULL;
57
56
struct io_overflow_cqe *ocqe;
58
57
struct io_rings *r = ctx->rings;
59
58
unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
···
63
64
unsigned int cq_shift = 0;
64
65
unsigned int sq_shift = 0;
65
66
unsigned int sq_entries, cq_entries;
67
+
int sq_pid = -1, sq_cpu = -1;
66
68
bool has_lock;
67
69
unsigned int i;
68
70
···
143
143
has_lock = mutex_trylock(&ctx->uring_lock);
144
144
145
145
if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
146
-
sq = ctx->sq_data;
147
-
if (!sq->thread)
148
-
sq = NULL;
146
+
struct io_sq_data *sq = ctx->sq_data;
147
+
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);
152
-
seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
157
+
seq_printf(m, "SqThread:\t%d\n", sq_pid);
158
+
seq_printf(m, "SqThreadCpu:\t%d\n", sq_cpu);
153
159
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
154
160
for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
155
161
struct file *f = io_file_from_index(&ctx->file_table, i);
-9
io_uring/rw.c
-9
io_uring/rw.c
···
913
913
kiocb_start_write(kiocb);
914
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
916
if (likely(req->file->f_op->write_iter))
926
917
ret2 = call_write_iter(req->file, kiocb, &s->iter);
927
918
else if (req->file->f_op->write)