[PATCH 6.1 004/451] io_uring: drop any code related to SCM_RIGHTS
From: Sasha Levin
Date: Mon Mar 25 2024 - 02:12:21 EST
From: Jens Axboe <axboe@xxxxxxxxx>
Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.
This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/linux/io_uring_types.h | 3 -
io_uring/filetable.c | 10 +--
io_uring/io_uring.c | 31 +------
io_uring/rsrc.c | 151 +--------------------------------
io_uring/rsrc.h | 15 ----
5 files changed, 8 insertions(+), 202 deletions(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index f5b687a787a34..37aeea266ebb3 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -330,9 +330,6 @@ struct io_ring_ctx {
struct list_head io_buffers_pages;
- #if defined(CONFIG_UNIX)
- struct socket *ring_sock;
- #endif
/* hashed buffered write serialization */
struct io_wq_hash *hash_map;
diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index b80614e7d6051..4660cb89ea9f5 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -95,12 +95,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
needs_switch = true;
}
- ret = io_scm_file_account(ctx, file);
- if (!ret) {
- *io_get_tag_slot(ctx->file_data, slot_index) = 0;
- io_fixed_file_set(file_slot, file);
- io_file_bitmap_set(&ctx->file_table, slot_index);
- }
+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
+ io_fixed_file_set(file_slot, file);
+ io_file_bitmap_set(&ctx->file_table, slot_index);
+ return 0;
err:
if (needs_switch)
io_rsrc_node_switch(ctx, ctx->file_data);
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index cf7dd62da0e37..415248c1f82c6 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
-#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
@@ -2628,12 +2627,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
if (ctx->mm_account) {
@@ -3438,32 +3431,12 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
*/
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
{
- struct file *file;
-#if defined(CONFIG_UNIX)
- int ret;
-
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ERR_PTR(ret);
-#endif
-
- file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+ return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
- if (IS_ERR(file)) {
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
- } else {
- ctx->ring_sock->file = file;
- }
-#endif
- return file;
}
static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 7ada0339b3870..ac658cfa89c63 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -494,11 +494,6 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
err = -EBADF;
break;
}
- err = io_scm_file_account(ctx, file);
- if (err) {
- fput(file);
- break;
- }
*io_get_tag_slot(data, i) = tag;
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
@@ -762,22 +757,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
for (i = 0; i < ctx->nr_user_files; i++) {
struct file *file = io_file_from_index(&ctx->file_table, i);
- /* skip scm accounted files, they'll be freed by ->ring_sock */
- if (!file || io_file_need_scm(file))
+ if (!file)
continue;
io_file_bitmap_clear(&ctx->file_table, i);
fput(file);
}
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#endif
io_free_file_tables(&ctx->file_table);
io_file_table_set_alloc_range(ctx, 0, 0);
io_rsrc_data_free(ctx->file_data);
@@ -805,134 +790,11 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
return ret;
}
-/*
- * 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
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sk = ctx->ring_sock->sk;
- struct sk_buff_head *head = &sk->sk_receive_queue;
- struct scm_fp_list *fpl;
- struct sk_buff *skb;
-
- if (likely(!io_file_need_scm(file)))
- return 0;
-
- /*
- * See if we can merge this file into an existing skb SCM_RIGHTS
- * file set. If there's no room, fall back to allocating a new skb
- * and filling it in.
- */
- spin_lock_irq(&head->lock);
- skb = skb_peek(head);
- if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
- __skb_unlink(skb, head);
- else
- skb = NULL;
- spin_unlock_irq(&head->lock);
-
- if (!skb) {
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- fpl->user = get_uid(current_user());
- fpl->max = SCM_MAX_FD;
- fpl->count = 0;
-
- UNIXCB(skb).fp = fpl;
- skb->sk = sk;
- skb->scm_io_uring = 1;
- skb->destructor = unix_destruct_scm;
- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
- }
-
- fpl = UNIXCB(skb).fp;
- fpl->fp[fpl->count++] = get_file(file);
- unix_inflight(fpl->user, file);
- skb_queue_head(head, skb);
- fput(file);
-#endif
- return 0;
-}
-
static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
{
struct file *file = prsrc->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;
-
- if (!io_file_need_scm(file)) {
- fput(file);
- return;
- }
-
- __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
}
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
@@ -986,21 +848,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
goto fail;
/*
- * Don't allow io_uring instances to be registered. If UNIX
- * isn't enabled, then this causes a reference cycle and this
- * instance can never get freed. If UNIX is enabled we'll
- * handle it just fine, but there's still no point in allowing
- * a ring fd as it doesn't support regular read/write anyway.
+ * Don't allow io_uring instances to be registered.
*/
if (io_is_uring_fops(file)) {
fput(file);
goto fail;
}
- ret = io_scm_file_account(ctx, file);
- if (ret) {
- fput(file);
- goto fail;
- }
file_slot = io_fixed_file_slot(&ctx->file_table, i);
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index acaf8dad05401..85f145607c620 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -77,21 +77,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags);
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
- return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
- struct file *file)
-{
- if (likely(!io_file_need_scm(file)))
- return 0;
- return __io_scm_file_account(ctx, file);
-}
-
int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args);
int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
--
2.43.0