struct file **files;
};
+enum {
+ FFD_F_ATOMIC,
+};
+
+struct fixed_file_data {
+ struct fixed_file_table *table;
+ struct io_ring_ctx *ctx;
+
+ struct percpu_ref refs;
+ struct llist_head put_llist;
+ unsigned long state;
+ struct work_struct ref_work;
+ struct completion done;
+};
+
struct io_ring_ctx {
struct {
struct percpu_ref refs;
* readers must ensure that ->refs is alive as long as the file* is
* used. Only updated through io_uring_register(2).
*/
- struct fixed_file_table *file_table;
+ struct fixed_file_data *file_data;
unsigned nr_user_files;
/* if used, fixed mapped user buffers */
int flags;
};
+struct io_files_update {
+ struct file *file;
+ u64 arg;
+ u32 nr_args;
+ u32 offset;
+};
+
struct io_async_connect {
struct sockaddr_storage address;
};
struct io_sr_msg sr_msg;
struct io_open open;
struct io_close close;
+ struct io_files_update files_update;
};
struct io_async_ctx *io;
static void __io_double_put_req(struct io_kiocb *req);
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
static void io_queue_linked_timeout(struct io_kiocb *req);
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+ struct io_uring_files_update *ip,
+ unsigned nr_args);
static struct kmem_cache *req_cachep;
if (*nr) {
kmem_cache_free_bulk(req_cachep, *nr, reqs);
percpu_ref_put_many(&ctx->refs, *nr);
+ percpu_ref_put_many(&ctx->file_data->refs, *nr);
*nr = 0;
}
}
if (req->io)
kfree(req->io);
- if (req->file && !(req->flags & REQ_F_FIXED_FILE))
- fput(req->file);
+ if (req->file) {
+ if (req->flags & REQ_F_FIXED_FILE)
+ percpu_ref_put(&ctx->file_data->refs);
+ else
+ fput(req->file);
+ }
if (req->flags & REQ_F_INFLIGHT) {
unsigned long flags;
return 0;
}
+static int io_files_update_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (sqe->flags || sqe->ioprio || sqe->rw_flags)
+ return -EINVAL;
+
+ req->files_update.offset = READ_ONCE(sqe->off);
+ req->files_update.nr_args = READ_ONCE(sqe->len);
+ if (!req->files_update.nr_args)
+ return -EINVAL;
+ req->files_update.arg = READ_ONCE(sqe->addr);
+ return 0;
+}
+
+static int io_files_update(struct io_kiocb *req, bool force_nonblock)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_uring_files_update up;
+ int ret;
+
+ if (force_nonblock) {
+ req->work.flags |= IO_WQ_WORK_NEEDS_FILES;
+ return -EAGAIN;
+ }
+
+ up.offset = req->files_update.offset;
+ up.fds = req->files_update.arg;
+
+ mutex_lock(&ctx->uring_lock);
+ ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
+ mutex_unlock(&ctx->uring_lock);
+
+ if (ret < 0)
+ req_set_fail_links(req);
+ io_cqring_add_event(req, ret);
+ io_put_req(req);
+ return 0;
+}
+
static int io_req_defer_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
case IORING_OP_CLOSE:
ret = io_close_prep(req, sqe);
break;
+ case IORING_OP_FILES_UPDATE:
+ ret = io_files_update_prep(req, sqe);
+ break;
default:
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
req->opcode);
}
ret = io_close(req, nxt, force_nonblock);
break;
+ case IORING_OP_FILES_UPDATE:
+ if (sqe) {
+ ret = io_files_update_prep(req, sqe);
+ if (ret)
+ break;
+ }
+ ret = io_files_update(req, force_nonblock);
+ break;
default:
ret = -EINVAL;
break;
{
struct fixed_file_table *table;
- table = &ctx->file_table[index >> IORING_FILE_TABLE_SHIFT];
- return table->files[index & IORING_FILE_TABLE_MASK];
+ table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
+ return table->files[index & IORING_FILE_TABLE_MASK];;
}
static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
return ret;
if (flags & IOSQE_FIXED_FILE) {
- if (unlikely(!ctx->file_table ||
+ if (unlikely(!ctx->file_data ||
(unsigned) fd >= ctx->nr_user_files))
return -EBADF;
fd = array_index_nospec(fd, ctx->nr_user_files);
if (!req->file)
return -EBADF;
req->flags |= REQ_F_FIXED_FILE;
+ percpu_ref_get(&ctx->file_data->refs);
} else {
if (req->needs_fixed_file)
return -EBADF;
#endif
}
+static void io_file_ref_kill(struct percpu_ref *ref)
+{
+ struct fixed_file_data *data;
+
+ data = container_of(ref, struct fixed_file_data, refs);
+ complete(&data->done);
+}
+
static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
+ struct fixed_file_data *data = ctx->file_data;
unsigned nr_tables, i;
- if (!ctx->file_table)
+ if (!data)
return -ENXIO;
+ /* protect against inflight atomic switch, which drops the ref */
+ flush_work(&data->ref_work);
+ percpu_ref_get(&data->refs);
+ percpu_ref_kill_and_confirm(&data->refs, io_file_ref_kill);
+ wait_for_completion(&data->done);
+ percpu_ref_put(&data->refs);
+ percpu_ref_exit(&data->refs);
+
__io_sqe_files_unregister(ctx);
nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
for (i = 0; i < nr_tables; i++)
- kfree(ctx->file_table[i].files);
- kfree(ctx->file_table);
- ctx->file_table = NULL;
+ kfree(data->table[i].files);
+ kfree(data->table);
+ kfree(data);
+ ctx->file_data = NULL;
ctx->nr_user_files = 0;
return 0;
}
}
#if defined(CONFIG_UNIX)
-static void io_destruct_skb(struct sk_buff *skb)
-{
- struct io_ring_ctx *ctx = skb->sk->sk_user_data;
-
- if (ctx->io_wq)
- io_wq_flush(ctx->io_wq);
-
- unix_destruct_scm(skb);
-}
-
/*
* Ensure the UNIX gc is aware of our file set, so we are certain that
* the io_uring can be safely unregistered on process exit, even if we have
fpl->max = SCM_MAX_FD;
fpl->count = nr_files;
UNIXCB(skb).fp = fpl;
- skb->destructor = io_destruct_skb;
+ skb->destructor = unix_destruct_scm;
refcount_add(skb->truesize, &sk->sk_wmem_alloc);
skb_queue_head(&sk->sk_receive_queue, skb);
int i;
for (i = 0; i < nr_tables; i++) {
- struct fixed_file_table *table = &ctx->file_table[i];
+ struct fixed_file_table *table = &ctx->file_data->table[i];
unsigned this_files;
this_files = min(nr_files, IORING_MAX_FILES_TABLE);
return 0;
for (i = 0; i < nr_tables; i++) {
- struct fixed_file_table *table = &ctx->file_table[i];
+ struct fixed_file_table *table = &ctx->file_data->table[i];
kfree(table->files);
}
return 1;
}
+static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
+{
+#if defined(CONFIG_UNIX)
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff_head list, *head = &sock->sk_receive_queue;
+ struct sk_buff *skb;
+ int i;
+
+ __skb_queue_head_init(&list);
+
+ /*
+ * Find the skb that holds this file in its SCM_RIGHTS. When found,
+ * remove this entry and rearrange the file array.
+ */
+ skb = skb_dequeue(head);
+ while (skb) {
+ struct scm_fp_list *fp;
+
+ fp = UNIXCB(skb).fp;
+ for (i = 0; i < fp->count; i++) {
+ int left;
+
+ if (fp->fp[i] != file)
+ continue;
+
+ unix_notinflight(fp->user, fp->fp[i]);
+ left = fp->count - 1 - i;
+ if (left) {
+ memmove(&fp->fp[i], &fp->fp[i + 1],
+ left * sizeof(struct file *));
+ }
+ fp->count--;
+ if (!fp->count) {
+ kfree_skb(skb);
+ skb = NULL;
+ } else {
+ __skb_queue_tail(&list, skb);
+ }
+ fput(file);
+ file = NULL;
+ break;
+ }
+
+ if (!file)
+ break;
+
+ __skb_queue_tail(&list, skb);
+
+ skb = skb_dequeue(head);
+ }
+
+ if (skb_peek(&list)) {
+ spin_lock_irq(&head->lock);
+ while ((skb = __skb_dequeue(&list)) != NULL)
+ __skb_queue_tail(head, skb);
+ spin_unlock_irq(&head->lock);
+ }
+#else
+ fput(file);
+#endif
+}
+
+struct io_file_put {
+ struct llist_node llist;
+ struct file *file;
+ struct completion *done;
+};
+
+static void io_ring_file_ref_switch(struct work_struct *work)
+{
+ struct io_file_put *pfile, *tmp;
+ struct fixed_file_data *data;
+ struct llist_node *node;
+
+ data = container_of(work, struct fixed_file_data, ref_work);
+
+ while ((node = llist_del_all(&data->put_llist)) != NULL) {
+ llist_for_each_entry_safe(pfile, tmp, node, llist) {
+ io_ring_file_put(data->ctx, pfile->file);
+ if (pfile->done)
+ complete(pfile->done);
+ else
+ kfree(pfile);
+ }
+ }
+
+ percpu_ref_get(&data->refs);
+ percpu_ref_switch_to_percpu(&data->refs);
+}
+
+static void io_file_data_ref_zero(struct percpu_ref *ref)
+{
+ struct fixed_file_data *data;
+
+ data = container_of(ref, struct fixed_file_data, refs);
+
+ /* we can't safely switch from inside this context, punt to wq */
+ queue_work(system_wq, &data->ref_work);
+}
+
static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args)
{
__s32 __user *fds = (__s32 __user *) arg;
unsigned nr_tables;
+ struct file *file;
int fd, ret = 0;
unsigned i;
- if (ctx->file_table)
+ if (ctx->file_data)
return -EBUSY;
if (!nr_args)
return -EINVAL;
if (nr_args > IORING_MAX_FIXED_FILES)
return -EMFILE;
+ ctx->file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
+ if (!ctx->file_data)
+ return -ENOMEM;
+ ctx->file_data->ctx = ctx;
+ init_completion(&ctx->file_data->done);
+
nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
- ctx->file_table = kcalloc(nr_tables, sizeof(struct fixed_file_table),
+ ctx->file_data->table = kcalloc(nr_tables,
+ sizeof(struct fixed_file_table),
GFP_KERNEL);
- if (!ctx->file_table)
+ if (!ctx->file_data->table) {
+ kfree(ctx->file_data);
+ ctx->file_data = NULL;
return -ENOMEM;
+ }
+
+ if (percpu_ref_init(&ctx->file_data->refs, io_file_data_ref_zero,
+ PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {
+ kfree(ctx->file_data->table);
+ kfree(ctx->file_data);
+ ctx->file_data = NULL;
+ return -ENOMEM;
+ }
+ ctx->file_data->put_llist.first = NULL;
+ INIT_WORK(&ctx->file_data->ref_work, io_ring_file_ref_switch);
if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) {
- kfree(ctx->file_table);
- ctx->file_table = NULL;
+ percpu_ref_exit(&ctx->file_data->refs);
+ kfree(ctx->file_data->table);
+ kfree(ctx->file_data);
+ ctx->file_data = NULL;
return -ENOMEM;
}
continue;
}
- table = &ctx->file_table[i >> IORING_FILE_TABLE_SHIFT];
+ table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
index = i & IORING_FILE_TABLE_MASK;
- table->files[index] = fget(fd);
+ file = fget(fd);
ret = -EBADF;
- if (!table->files[index])
+ if (!file)
break;
+
/*
* Don't allow io_uring instances to be registered. If UNIX
* isn't enabled, then this causes a reference cycle and this
* handle it just fine, but there's still no point in allowing
* a ring fd as it doesn't support regular read/write anyway.
*/
- if (table->files[index]->f_op == &io_uring_fops) {
- fput(table->files[index]);
+ if (file->f_op == &io_uring_fops) {
+ fput(file);
break;
}
ret = 0;
+ table->files[index] = file;
}
if (ret) {
for (i = 0; i < ctx->nr_user_files; i++) {
- struct file *file;
-
file = io_file_from_index(ctx, i);
if (file)
fput(file);
}
for (i = 0; i < nr_tables; i++)
- kfree(ctx->file_table[i].files);
+ kfree(ctx->file_data->table[i].files);
- kfree(ctx->file_table);
- ctx->file_table = NULL;
+ kfree(ctx->file_data->table);
+ kfree(ctx->file_data);
+ ctx->file_data = NULL;
ctx->nr_user_files = 0;
return ret;
}
return ret;
}
-static void io_sqe_file_unregister(struct io_ring_ctx *ctx, int index)
-{
-#if defined(CONFIG_UNIX)
- struct file *file = io_file_from_index(ctx, index);
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head list, *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
- int i;
-
- __skb_queue_head_init(&list);
-
- /*
- * Find the skb that holds this file in its SCM_RIGHTS. When found,
- * remove this entry and rearrange the file array.
- */
- skb = skb_dequeue(head);
- while (skb) {
- struct scm_fp_list *fp;
-
- fp = UNIXCB(skb).fp;
- for (i = 0; i < fp->count; i++) {
- int left;
-
- if (fp->fp[i] != file)
- continue;
-
- unix_notinflight(fp->user, fp->fp[i]);
- left = fp->count - 1 - i;
- if (left) {
- memmove(&fp->fp[i], &fp->fp[i + 1],
- left * sizeof(struct file *));
- }
- fp->count--;
- if (!fp->count) {
- kfree_skb(skb);
- skb = NULL;
- } else {
- __skb_queue_tail(&list, skb);
- }
- fput(file);
- file = NULL;
- break;
- }
-
- if (!file)
- break;
-
- __skb_queue_tail(&list, skb);
-
- skb = skb_dequeue(head);
- }
-
- if (skb_peek(&list)) {
- spin_lock_irq(&head->lock);
- while ((skb = __skb_dequeue(&list)) != NULL)
- __skb_queue_tail(head, skb);
- spin_unlock_irq(&head->lock);
- }
-#else
- fput(io_file_from_index(ctx, index));
-#endif
-}
-
static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
int index)
{
#endif
}
-static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
- unsigned nr_args)
+static void io_atomic_switch(struct percpu_ref *ref)
{
- struct io_uring_files_update up;
+ struct fixed_file_data *data;
+
+ data = container_of(ref, struct fixed_file_data, refs);
+ clear_bit(FFD_F_ATOMIC, &data->state);
+}
+
+static bool io_queue_file_removal(struct fixed_file_data *data,
+ struct file *file)
+{
+ struct io_file_put *pfile, pfile_stack;
+ DECLARE_COMPLETION_ONSTACK(done);
+
+ /*
+ * If we fail allocating the struct we need for doing async reomval
+ * of this file, just punt to sync and wait for it.
+ */
+ pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
+ if (!pfile) {
+ pfile = &pfile_stack;
+ pfile->done = &done;
+ }
+
+ pfile->file = file;
+ llist_add(&pfile->llist, &data->put_llist);
+
+ if (pfile == &pfile_stack) {
+ if (!test_and_set_bit(FFD_F_ATOMIC, &data->state)) {
+ percpu_ref_put(&data->refs);
+ percpu_ref_switch_to_atomic(&data->refs,
+ io_atomic_switch);
+ }
+ wait_for_completion(&done);
+ flush_work(&data->ref_work);
+ return false;
+ }
+
+ return true;
+}
+
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+ struct io_uring_files_update *up,
+ unsigned nr_args)
+{
+ struct fixed_file_data *data = ctx->file_data;
+ bool ref_switch = false;
+ struct file *file;
__s32 __user *fds;
int fd, i, err;
__u32 done;
- if (!ctx->file_table)
- return -ENXIO;
- if (!nr_args)
- return -EINVAL;
- if (copy_from_user(&up, arg, sizeof(up)))
- return -EFAULT;
- if (up.resv)
- return -EINVAL;
- if (check_add_overflow(up.offset, nr_args, &done))
+ if (check_add_overflow(up->offset, nr_args, &done))
return -EOVERFLOW;
if (done > ctx->nr_user_files)
return -EINVAL;
done = 0;
- fds = u64_to_user_ptr(up.fds);
+ fds = u64_to_user_ptr(up->fds);
while (nr_args) {
struct fixed_file_table *table;
unsigned index;
err = -EFAULT;
break;
}
- i = array_index_nospec(up.offset, ctx->nr_user_files);
- table = &ctx->file_table[i >> IORING_FILE_TABLE_SHIFT];
+ i = array_index_nospec(up->offset, ctx->nr_user_files);
+ table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
index = i & IORING_FILE_TABLE_MASK;
if (table->files[index]) {
- io_sqe_file_unregister(ctx, i);
+ file = io_file_from_index(ctx, index);
table->files[index] = NULL;
+ if (io_queue_file_removal(data, file))
+ ref_switch = true;
}
if (fd != -1) {
- struct file *file;
-
file = fget(fd);
if (!file) {
err = -EBADF;
}
nr_args--;
done++;
- up.offset++;
+ up->offset++;
+ }
+
+ if (ref_switch && !test_and_set_bit(FFD_F_ATOMIC, &data->state)) {
+ percpu_ref_put(&data->refs);
+ percpu_ref_switch_to_atomic(&data->refs, io_atomic_switch);
}
return done ? done : err;
}
+static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args)
+{
+ struct io_uring_files_update up;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+ if (!nr_args)
+ return -EINVAL;
+ if (copy_from_user(&up, arg, sizeof(up)))
+ return -EFAULT;
+ if (up.resv)
+ return -EINVAL;
+
+ return __io_sqe_files_update(ctx, &up, nr_args);
+}
static void io_put_work(struct io_wq_work *work)
{
#if defined(CONFIG_UNIX)
ctx->ring_sock->file = file;
- ctx->ring_sock->sk->sk_user_data = ctx;
#endif
fd_install(ret, file);
return ret;
if (percpu_ref_is_dying(&ctx->refs))
return -ENXIO;
- percpu_ref_kill(&ctx->refs);
+ if (opcode != IORING_UNREGISTER_FILES &&
+ opcode != IORING_REGISTER_FILES_UPDATE) {
+ percpu_ref_kill(&ctx->refs);
- /*
- * Drop uring mutex before waiting for references to exit. If another
- * thread is currently inside io_uring_enter() it might need to grab
- * the uring_lock to make progress. If we hold it here across the drain
- * wait, then we can deadlock. It's safe to drop the mutex here, since
- * no new references will come in after we've killed the percpu ref.
- */
- mutex_unlock(&ctx->uring_lock);
- wait_for_completion(&ctx->completions[0]);
- mutex_lock(&ctx->uring_lock);
+ /*
+ * Drop uring mutex before waiting for references to exit. If
+ * another thread is currently inside io_uring_enter() it might
+ * need to grab the uring_lock to make progress. If we hold it
+ * here across the drain wait, then we can deadlock. It's safe
+ * to drop the mutex here, since no new references will come in
+ * after we've killed the percpu ref.
+ */
+ mutex_unlock(&ctx->uring_lock);
+ wait_for_completion(&ctx->completions[0]);
+ mutex_lock(&ctx->uring_lock);
+ }
switch (opcode) {
case IORING_REGISTER_BUFFERS:
break;
}
- /* bring the ctx back to life */
- reinit_completion(&ctx->completions[0]);
- percpu_ref_reinit(&ctx->refs);
+
+ if (opcode != IORING_UNREGISTER_FILES &&
+ opcode != IORING_REGISTER_FILES_UPDATE) {
+ /* bring the ctx back to life */
+ reinit_completion(&ctx->completions[0]);
+ percpu_ref_reinit(&ctx->refs);
+ }
return ret;
}
projects / linux-2.6-microblaze.git / commitdiff