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
diff --git a/fs/file.c b/fs/file.c
index c0b6096..dab120b 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -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 @@
struct files_struct * files = tsk->files;
if (files) {
- io_uring_files_cancel(files);
task_lock(tsk);
tsk->files = NULL;
task_unlock(tsk);
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 7e35283..ca46f31 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -992,6 +992,10 @@
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 @@
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 @@
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 @@
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 @@
/* 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 @@
kfree(data);
ctx->file_data = NULL;
ctx->nr_user_files = 0;
+ destroy_fixed_file_ref_node(backup_node);
return 0;
}
@@ -7758,11 +7788,7 @@
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 @@
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);
diff --git a/kernel/exit.c b/kernel/exit.c
index 3594291..04029e3 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -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 @@
schedule();
}
+ io_uring_files_cancel(tsk->files);
exit_signals(tsk); /* sets PF_EXITING */
/* sync mm's RSS info before statistics gathering */
