[PATCH for-next 0/4] io_uring/zc fix and improvements

[PATCH for-next 0/4] io_uring/zc fix and improvements

[Pavel Begunkov]

It mainly fixes net/zc memory accounting error handling and then makes
it more consistent with registered buffers mem accounting.

Pavel Begunkov (4):
  io_uring/net: improve io_get_notif_slot types
  io_uring/net: checks errors of zc mem accounting
  io_uring/net: make page accounting more consistent
  io_uring/net: use unsigned for flags

 io_uring/net.c   |  8 +++++---
 io_uring/notif.c |  9 ++++-----
 io_uring/notif.h | 21 ++++++++++++++++++++-
 io_uring/rsrc.c  | 12 ++++--------
 io_uring/rsrc.h  |  9 +++++++++
 5 files changed, 42 insertions(+), 17 deletions(-)

-- 
2.37.0

[PATCH for-next 1/4] io_uring/net: improve io_get_notif_slot types

[Pavel Begunkov]

Don't use signed int for slot indexing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/notif.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/notif.h b/io_uring/notif.h
index 6cd73d7b965b..3e05d2cecb6f 100644
--- a/io_uring/notif.h
+++ b/io_uring/notif.h
@@ -67,7 +67,7 @@ static inline struct io_notif *io_get_notif(struct io_ring_ctx *ctx,
 }
 
 static inline struct io_notif_slot *io_get_notif_slot(struct io_ring_ctx *ctx,
-						      int idx)
+						      unsigned idx)
 	__must_hold(&ctx->uring_lock)
 {
 	if (idx >= ctx->nr_notif_slots)
-- 
2.37.0

[PATCH for-next 2/4] io_uring/net: checks errors of zc mem accounting

[Pavel Begunkov]

mm_account_pinned_pages() may fail, don't ignore the return value.

Fixes: d3b8269075f67 ("io_uring: account locked pages for non-fixed zc")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/net.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 62be89837d82..8fb8469c3315 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -985,7 +985,9 @@ int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
 					  &msg.msg_iter);
 		if (unlikely(ret))
 			return ret;
-		mm_account_pinned_pages(&notif->uarg.mmp, zc->len);
+		ret = mm_account_pinned_pages(&notif->uarg.mmp, zc->len);
+		if (unlikely(ret))
+			return ret;
 	}
 
 	if (zc->addr) {
-- 
2.37.0

[PATCH for-next 3/4] io_uring/net: make page accounting more consistent

[Pavel Begunkov]

Make network page accounting more consistent with how buffer
registration is working, i.e. account all memory to ctx->user.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/net.c   |  2 +-
 io_uring/notif.c |  9 ++++-----
 io_uring/notif.h | 19 +++++++++++++++++++
 io_uring/rsrc.c  | 12 ++++--------
 io_uring/rsrc.h  |  9 +++++++++
 5 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 8fb8469c3315..c13d971c7826 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -985,7 +985,7 @@ int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
 					  &msg.msg_iter);
 		if (unlikely(ret))
 			return ret;
-		ret = mm_account_pinned_pages(&notif->uarg.mmp, zc->len);
+		ret = io_notif_account_mem(notif, zc->len);
 		if (unlikely(ret))
 			return ret;
 	}
diff --git a/io_uring/notif.c b/io_uring/notif.c
index a93887451bbb..e986a0ed958c 100644
--- a/io_uring/notif.c
+++ b/io_uring/notif.c
@@ -14,12 +14,10 @@ static void __io_notif_complete_tw(struct callback_head *cb)
 	struct io_notif *notif = container_of(cb, struct io_notif, task_work);
 	struct io_rsrc_node *rsrc_node = notif->rsrc_node;
 	struct io_ring_ctx *ctx = notif->ctx;
-	struct mmpin *mmp = &notif->uarg.mmp;
 
-	if (mmp->user) {
-		atomic_long_sub(mmp->num_pg, &mmp->user->locked_vm);
-		free_uid(mmp->user);
-		mmp->user = NULL;
+	if (notif->account_pages && ctx->user) {
+		__io_unaccount_mem(ctx->user, notif->account_pages);
+		notif->account_pages = 0;
 	}
 	if (likely(notif->task)) {
 		io_put_task(notif->task, 1);
@@ -121,6 +119,7 @@ struct io_notif *io_alloc_notif(struct io_ring_ctx *ctx,
 		notif->ctx = ctx;
 		notif->uarg.flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;
 		notif->uarg.callback = io_uring_tx_zerocopy_callback;
+		notif->account_pages = 0;
 	}
 
 	notif->seq = slot->seq++;
diff --git a/io_uring/notif.h b/io_uring/notif.h
index 3e05d2cecb6f..d6f366b1518b 100644
--- a/io_uring/notif.h
+++ b/io_uring/notif.h
@@ -5,6 +5,8 @@
 #include <net/sock.h>
 #include <linux/nospec.h>
 
+#include "rsrc.h"
+
 #define IO_NOTIF_SPLICE_BATCH	32
 #define IORING_MAX_NOTIF_SLOTS (1U << 10)
 
@@ -23,6 +25,8 @@ struct io_notif {
 	/* hook into ctx->notif_list and ctx->notif_list_locked */
 	struct list_head	cache_node;
 
+	unsigned long		account_pages;
+
 	union {
 		struct callback_head	task_work;
 		struct work_struct	commit_work;
@@ -85,3 +89,18 @@ static inline void io_notif_slot_flush_submit(struct io_notif_slot *slot,
 	}
 	io_notif_slot_flush(slot);
 }
+
+static inline int io_notif_account_mem(struct io_notif *notif, unsigned len)
+{
+	struct io_ring_ctx *ctx = notif->ctx;
+	unsigned nr_pages = (len >> PAGE_SHIFT) + 2;
+	int ret;
+
+	if (ctx->user) {
+		ret = __io_account_mem(ctx->user, nr_pages);
+		if (ret)
+			return ret;
+		notif->account_pages += nr_pages;
+	}
+	return 0;
+}
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 9165fdf64269..59704b9ac537 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -44,17 +44,13 @@ void io_rsrc_refs_drop(struct io_ring_ctx *ctx)
 	}
 }
 
-static inline void __io_unaccount_mem(struct user_struct *user,
-				      unsigned long nr_pages)
-{
-	atomic_long_sub(nr_pages, &user->locked_vm);
-}
-
-static inline int __io_account_mem(struct user_struct *user,
-				   unsigned long nr_pages)
+int __io_account_mem(struct user_struct *user, unsigned long nr_pages)
 {
 	unsigned long page_limit, cur_pages, new_pages;
 
+	if (!nr_pages)
+		return 0;
+
 	/* Don't allow more pages than we can safely lock */
 	page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 21813a23215f..f3a9a177941f 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -169,4 +169,13 @@ static inline u64 *io_get_tag_slot(struct io_rsrc_data *data, unsigned int idx)
 
 int io_rsrc_update(struct io_kiocb *req, unsigned int issue_flags);
 int io_rsrc_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+
+int __io_account_mem(struct user_struct *user, unsigned long nr_pages);
+
+static inline void __io_unaccount_mem(struct user_struct *user,
+				      unsigned long nr_pages)
+{
+	atomic_long_sub(nr_pages, &user->locked_vm);
+}
+
 #endif
-- 
2.37.0

[PATCH for-next 4/4] io_uring/net: use unsigned for flags

[Pavel Begunkov]

Use unsigned int type for msg flags.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/net.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index c13d971c7826..8276b9537194 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -55,10 +55,10 @@ struct io_sr_msg {
 		struct user_msghdr __user	*umsg;
 		void __user			*buf;
 	};
-	int				msg_flags;
+	unsigned			msg_flags;
+	unsigned			flags;
 	size_t				len;
 	size_t				done_io;
-	unsigned int			flags;
 };
 
 struct io_sendzc {
-- 
2.37.0

Re: [PATCH for-next 0/4] io_uring/zc fix and improvements

[Jens Axboe]

On Mon, 25 Jul 2022 10:52:02 +0100, Pavel Begunkov wrote:
> It mainly fixes net/zc memory accounting error handling and then makes
> it more consistent with registered buffers mem accounting.
> 
> Pavel Begunkov (4):
>   io_uring/net: improve io_get_notif_slot types
>   io_uring/net: checks errors of zc mem accounting
>   io_uring/net: make page accounting more consistent
>   io_uring/net: use unsigned for flags
> 
> [...]

Applied, thanks!

[1/4] io_uring/net: improve io_get_notif_slot types
      commit: cb309ae49da7a7c28f0051deea13970291134fac
[2/4] io_uring/net: checks errors of zc mem accounting
      commit: 2e32ba5607ee2b668baa8831dd74f7cc867a1f7e
[3/4] io_uring/net: make page accounting more consistent
      commit: 6a9ce66f4d0872861e0bbc67eee6ce5dca5dd886
[4/4] io_uring/net: use unsigned for flags
      commit: 293402e564a7391f38541c7694e736f5fde20aea

Best regards,
-- 
Jens Axboe