Commit dc3e24b2 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'io_uring-5.11-2021-01-01' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "A few fixes that should go into 5.11, all marked for stable as well:

   - Fix issue around identity COW'ing and users that share a ring
     across processes

   - Fix a hang associated with unregistering fixed files (Pavel)

   - Move the 'process is exiting' cancelation a bit earlier, so
     task_works aren't affected by it (Pavel)"

* tag 'io_uring-5.11-2021-01-01' of git://git.kernel.dk/linux-block:
  kernel/io_uring: cancel io_uring before task works
  io_uring: fix io_sqe_files_unregister() hangs
  io_uring: add a helper for setting a ref node
  io_uring: don't assume mm is constant across submits
parents cedd1862 b1b6b5a3
......@@ -21,7 +21,6 @@
#include <linux/rcupdate.h>
#include <linux/close_range.h>
#include <net/sock.h>
#include <linux/io_uring.h>
unsigned int sysctl_nr_open __read_mostly = 1024*1024;
unsigned int sysctl_nr_open_min = BITS_PER_LONG;
......@@ -428,7 +427,6 @@ void exit_files(struct task_struct *tsk)
struct files_struct * files = tsk->files;
if (files) {
io_uring_files_cancel(files);
task_lock(tsk);
tsk->files = NULL;
task_unlock(tsk);
......
......@@ -992,6 +992,10 @@ enum io_mem_account {
ACCT_PINNED,
};
static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node);
static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
struct io_ring_ctx *ctx);
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
struct io_comp_state *cs);
static void io_cqring_fill_event(struct io_kiocb *req, long res);
......@@ -1501,6 +1505,13 @@ static bool io_grab_identity(struct io_kiocb *req)
spin_unlock_irq(&ctx->inflight_lock);
req->work.flags |= IO_WQ_WORK_FILES;
}
if (!(req->work.flags & IO_WQ_WORK_MM) &&
(def->work_flags & IO_WQ_WORK_MM)) {
if (id->mm != current->mm)
return false;
mmgrab(id->mm);
req->work.flags |= IO_WQ_WORK_MM;
}
return true;
}
......@@ -1525,13 +1536,6 @@ static void io_prep_async_work(struct io_kiocb *req)
req->work.flags |= IO_WQ_WORK_UNBOUND;
}
/* ->mm can never change on us */
if (!(req->work.flags & IO_WQ_WORK_MM) &&
(def->work_flags & IO_WQ_WORK_MM)) {
mmgrab(id->mm);
req->work.flags |= IO_WQ_WORK_MM;
}
/* if we fail grabbing identity, we must COW, regrab, and retry */
if (io_grab_identity(req))
return;
......@@ -7231,14 +7235,28 @@ static void io_file_ref_kill(struct percpu_ref *ref)
complete(&data->done);
}
static void io_sqe_files_set_node(struct fixed_file_data *file_data,
struct fixed_file_ref_node *ref_node)
{
spin_lock_bh(&file_data->lock);
file_data->node = ref_node;
list_add_tail(&ref_node->node, &file_data->ref_list);
spin_unlock_bh(&file_data->lock);
percpu_ref_get(&file_data->refs);
}
static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
struct fixed_file_data *data = ctx->file_data;
struct fixed_file_ref_node *ref_node = NULL;
struct fixed_file_ref_node *backup_node, *ref_node = NULL;
unsigned nr_tables, i;
int ret;
if (!data)
return -ENXIO;
backup_node = alloc_fixed_file_ref_node(ctx);
if (!backup_node)
return -ENOMEM;
spin_lock_bh(&data->lock);
ref_node = data->node;
......@@ -7250,7 +7268,18 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
/* wait for all refs nodes to complete */
flush_delayed_work(&ctx->file_put_work);
wait_for_completion(&data->done);
do {
ret = wait_for_completion_interruptible(&data->done);
if (!ret)
break;
ret = io_run_task_work_sig();
if (ret < 0) {
percpu_ref_resurrect(&data->refs);
reinit_completion(&data->done);
io_sqe_files_set_node(data, backup_node);
return ret;
}
} while (1);
__io_sqe_files_unregister(ctx);
nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
......@@ -7261,6 +7290,7 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
kfree(data);
ctx->file_data = NULL;
ctx->nr_user_files = 0;
destroy_fixed_file_ref_node(backup_node);
return 0;
}
......@@ -7758,11 +7788,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
return PTR_ERR(ref_node);
}
file_data->node = ref_node;
spin_lock_bh(&file_data->lock);
list_add_tail(&ref_node->node, &file_data->ref_list);
spin_unlock_bh(&file_data->lock);
percpu_ref_get(&file_data->refs);
io_sqe_files_set_node(file_data, ref_node);
return ret;
out_fput:
for (i = 0; i < ctx->nr_user_files; i++) {
......@@ -7918,11 +7944,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
if (needs_switch) {
percpu_ref_kill(&data->node->refs);
spin_lock_bh(&data->lock);
list_add_tail(&ref_node->node, &data->ref_list);
data->node = ref_node;
spin_unlock_bh(&data->lock);
percpu_ref_get(&ctx->file_data->refs);
io_sqe_files_set_node(data, ref_node);
} else
destroy_fixed_file_ref_node(ref_node);
......
......@@ -63,6 +63,7 @@
#include <linux/random.h>
#include <linux/rcuwait.h>
#include <linux/compat.h>
#include <linux/io_uring.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
......@@ -776,6 +777,7 @@ void __noreturn do_exit(long code)
schedule();
}
io_uring_files_cancel(tsk->files);
exit_signals(tsk); /* sets PF_EXITING */
/* sync mm's RSS info before statistics gathering */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment