linux/io_uring/fdinfo.c
Jens Axboe ea97cbebaf io_uring/fdinfo: include locked hash table in fdinfo output
A previous commit split the hash table for polled requests into two
parts, but didn't get the fdinfo output updated. This means that it's
less useful for debugging, as we may think a given request is not pending
poll.

Fix this up by dumping the locked hash table contents too.

Fixes: 9ca9fb24d5 ("io_uring: mutex locked poll hashing")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-10 10:24:52 -07:00

219 lines
6.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "sqpoll.h"
#include "fdinfo.h"
#include "cancel.h"
#include "rsrc.h"
#ifdef CONFIG_PROC_FS
static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id,
const struct cred *cred)
{
struct user_namespace *uns = seq_user_ns(m);
struct group_info *gi;
kernel_cap_t cap;
unsigned __capi;
int g;
seq_printf(m, "%5d\n", id);
seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
seq_puts(m, "\n\tGroups:\t");
gi = cred->group_info;
for (g = 0; g < gi->ngroups; g++) {
seq_put_decimal_ull(m, g ? " " : "",
from_kgid_munged(uns, gi->gid[g]));
}
seq_puts(m, "\n\tCapEff:\t");
cap = cred->cap_effective;
CAP_FOR_EACH_U32(__capi)
seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
seq_putc(m, '\n');
return 0;
}
static __cold void __io_uring_show_fdinfo(struct io_ring_ctx *ctx,
struct seq_file *m)
{
struct io_sq_data *sq = NULL;
struct io_overflow_cqe *ocqe;
struct io_rings *r = ctx->rings;
unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1;
unsigned int sq_head = READ_ONCE(r->sq.head);
unsigned int sq_tail = READ_ONCE(r->sq.tail);
unsigned int cq_head = READ_ONCE(r->cq.head);
unsigned int cq_tail = READ_ONCE(r->cq.tail);
unsigned int cq_shift = 0;
unsigned int sq_shift = 0;
unsigned int sq_entries, cq_entries;
bool has_lock;
unsigned int i;
if (ctx->flags & IORING_SETUP_CQE32)
cq_shift = 1;
if (ctx->flags & IORING_SETUP_SQE128)
sq_shift = 1;
/*
* we may get imprecise sqe and cqe info if uring is actively running
* since we get cached_sq_head and cached_cq_tail without uring_lock
* and sq_tail and cq_head are changed by userspace. But it's ok since
* we usually use these info when it is stuck.
*/
seq_printf(m, "SqMask:\t0x%x\n", sq_mask);
seq_printf(m, "SqHead:\t%u\n", sq_head);
seq_printf(m, "SqTail:\t%u\n", sq_tail);
seq_printf(m, "CachedSqHead:\t%u\n", ctx->cached_sq_head);
seq_printf(m, "CqMask:\t0x%x\n", cq_mask);
seq_printf(m, "CqHead:\t%u\n", cq_head);
seq_printf(m, "CqTail:\t%u\n", cq_tail);
seq_printf(m, "CachedCqTail:\t%u\n", ctx->cached_cq_tail);
seq_printf(m, "SQEs:\t%u\n", sq_tail - sq_head);
sq_entries = min(sq_tail - sq_head, ctx->sq_entries);
for (i = 0; i < sq_entries; i++) {
unsigned int entry = i + sq_head;
struct io_uring_sqe *sqe;
unsigned int sq_idx;
sq_idx = READ_ONCE(ctx->sq_array[entry & sq_mask]);
if (sq_idx > sq_mask)
continue;
sqe = &ctx->sq_sqes[sq_idx << sq_shift];
seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, "
"addr:0x%llx, rw_flags:0x%x, buf_index:%d "
"user_data:%llu",
sq_idx, io_uring_get_opcode(sqe->opcode), sqe->fd,
sqe->flags, (unsigned long long) sqe->off,
(unsigned long long) sqe->addr, sqe->rw_flags,
sqe->buf_index, sqe->user_data);
if (sq_shift) {
u64 *sqeb = (void *) (sqe + 1);
int size = sizeof(struct io_uring_sqe) / sizeof(u64);
int j;
for (j = 0; j < size; j++) {
seq_printf(m, ", e%d:0x%llx", j,
(unsigned long long) *sqeb);
sqeb++;
}
}
seq_printf(m, "\n");
}
seq_printf(m, "CQEs:\t%u\n", cq_tail - cq_head);
cq_entries = min(cq_tail - cq_head, ctx->cq_entries);
for (i = 0; i < cq_entries; i++) {
unsigned int entry = i + cq_head;
struct io_uring_cqe *cqe = &r->cqes[(entry & cq_mask) << cq_shift];
seq_printf(m, "%5u: user_data:%llu, res:%d, flag:%x",
entry & cq_mask, cqe->user_data, cqe->res,
cqe->flags);
if (cq_shift)
seq_printf(m, ", extra1:%llu, extra2:%llu\n",
cqe->big_cqe[0], cqe->big_cqe[1]);
seq_printf(m, "\n");
}
/*
* Avoid ABBA deadlock between the seq lock and the io_uring mutex,
* since fdinfo case grabs it in the opposite direction of normal use
* cases. If we fail to get the lock, we just don't iterate any
* structures that could be going away outside the io_uring mutex.
*/
has_lock = mutex_trylock(&ctx->uring_lock);
if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
sq = ctx->sq_data;
if (!sq->thread)
sq = NULL;
}
seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
struct file *f = io_file_from_index(&ctx->file_table, i);
if (f)
seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
else
seq_printf(m, "%5u: <none>\n", i);
}
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
struct io_mapped_ubuf *buf = ctx->user_bufs[i];
unsigned int len = buf->ubuf_end - buf->ubuf;
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
}
if (has_lock && !xa_empty(&ctx->personalities)) {
unsigned long index;
const struct cred *cred;
seq_printf(m, "Personalities:\n");
xa_for_each(&ctx->personalities, index, cred)
io_uring_show_cred(m, index, cred);
}
seq_puts(m, "PollList:\n");
for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
struct io_hash_bucket *hbl = &ctx->cancel_table_locked.hbs[i];
struct io_kiocb *req;
spin_lock(&hb->lock);
hlist_for_each_entry(req, &hb->list, hash_node)
seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
task_work_pending(req->task));
spin_unlock(&hb->lock);
if (!has_lock)
continue;
hlist_for_each_entry(req, &hbl->list, hash_node)
seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
task_work_pending(req->task));
}
if (has_lock)
mutex_unlock(&ctx->uring_lock);
seq_puts(m, "CqOverflowList:\n");
spin_lock(&ctx->completion_lock);
list_for_each_entry(ocqe, &ctx->cq_overflow_list, list) {
struct io_uring_cqe *cqe = &ocqe->cqe;
seq_printf(m, " user_data=%llu, res=%d, flags=%x\n",
cqe->user_data, cqe->res, cqe->flags);
}
spin_unlock(&ctx->completion_lock);
}
__cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
{
struct io_ring_ctx *ctx = f->private_data;
if (percpu_ref_tryget(&ctx->refs)) {
__io_uring_show_fdinfo(ctx, m);
percpu_ref_put(&ctx->refs);
}
}
#endif