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authorJens Axboe <axboe@kernel.dk>2021-02-09 20:14:12 -0700
committerJens Axboe <axboe@kernel.dk>2021-02-10 07:33:15 -0700
commit26bfa89e25f42d2b26fe951bbcf04bb13937fbba (patch)
treedbf937a84c7d83c2ae17c4affd6ad335b0d38c9c
parent91f245d5d5de0802428a478802ec051f7de2f5d6 (diff)
io_uring: place ring SQ/CQ arrays under memcg memory limits
Instead of imposing rlimit memlock limits for the rings themselves, ensure that we account them properly under memcg with __GFP_ACCOUNT. We retain rlimit memlock for registered buffers, this is just for the ring arrays themselves. Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--fs/io_uring.c85
1 files changed, 10 insertions, 75 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index bffed6aa5722..7a1e4ecf5f94 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1017,11 +1017,6 @@ static const struct io_op_def io_op_defs[] = {
},
};
-enum io_mem_account {
- ACCT_LOCKED,
- ACCT_PINNED,
-};
-
static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
struct task_struct *task,
struct files_struct *files);
@@ -8355,25 +8350,16 @@ static inline int __io_account_mem(struct user_struct *user,
return 0;
}
-static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
- enum io_mem_account acct)
+static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
{
if (ctx->limit_mem)
__io_unaccount_mem(ctx->user, nr_pages);
- if (ctx->mm_account) {
- if (acct == ACCT_LOCKED) {
- mmap_write_lock(ctx->mm_account);
- ctx->mm_account->locked_vm -= nr_pages;
- mmap_write_unlock(ctx->mm_account);
- }else if (acct == ACCT_PINNED) {
- atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
- }
- }
+ if (ctx->mm_account)
+ atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
}
-static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
- enum io_mem_account acct)
+static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
{
int ret;
@@ -8383,15 +8369,8 @@ static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
return ret;
}
- if (ctx->mm_account) {
- if (acct == ACCT_LOCKED) {
- mmap_write_lock(ctx->mm_account);
- ctx->mm_account->locked_vm += nr_pages;
- mmap_write_unlock(ctx->mm_account);
- } else if (acct == ACCT_PINNED) {
- atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
- }
- }
+ if (ctx->mm_account)
+ atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
return 0;
}
@@ -8411,7 +8390,7 @@ static void io_mem_free(void *ptr)
static void *io_mem_alloc(size_t size)
{
gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
- __GFP_NORETRY;
+ __GFP_NORETRY | __GFP_ACCOUNT;
return (void *) __get_free_pages(gfp_flags, get_order(size));
}
@@ -8445,18 +8424,6 @@ static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
return off;
}
-static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
-{
- size_t pages;
-
- pages = (size_t)1 << get_order(
- rings_size(sq_entries, cq_entries, NULL));
- pages += (size_t)1 << get_order(
- array_size(sizeof(struct io_uring_sqe), sq_entries));
-
- return pages;
-}
-
static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
{
int i, j;
@@ -8471,7 +8438,7 @@ static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
unpin_user_page(imu->bvec[j].bv_page);
if (imu->acct_pages)
- io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED);
+ io_unaccount_mem(ctx, imu->acct_pages);
kvfree(imu->bvec);
imu->nr_bvecs = 0;
}
@@ -8569,7 +8536,7 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
if (!imu->acct_pages)
return 0;
- ret = io_account_mem(ctx, imu->acct_pages, ACCT_PINNED);
+ ret = io_account_mem(ctx, imu->acct_pages);
if (ret)
imu->acct_pages = 0;
return ret;
@@ -8949,14 +8916,6 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
/* if we failed setting up the ctx, we might not have any rings */
io_iopoll_try_reap_events(ctx);
- /*
- * Do this upfront, so we won't have a grace period where the ring
- * is closed but resources aren't reaped yet. This can cause
- * spurious failure in setting up a new ring.
- */
- io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries),
- ACCT_LOCKED);
-
INIT_WORK(&ctx->exit_work, io_ring_exit_work);
/*
* Use system_unbound_wq to avoid spawning tons of event kworkers
@@ -9780,7 +9739,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p,
struct user_struct *user = NULL;
struct io_ring_ctx *ctx;
struct file *file;
- bool limit_mem;
int ret;
if (!entries)
@@ -9821,26 +9779,14 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p,
}
user = get_uid(current_user());
- limit_mem = !capable(CAP_IPC_LOCK);
-
- if (limit_mem) {
- ret = __io_account_mem(user,
- ring_pages(p->sq_entries, p->cq_entries));
- if (ret) {
- free_uid(user);
- return ret;
- }
- }
ctx = io_ring_ctx_alloc(p);
if (!ctx) {
- if (limit_mem)
- __io_unaccount_mem(user, ring_pages(p->sq_entries,
- p->cq_entries));
free_uid(user);
return -ENOMEM;
}
ctx->compat = in_compat_syscall();
+ ctx->limit_mem = !capable(CAP_IPC_LOCK);
ctx->user = user;
ctx->creds = get_current_cred();
#ifdef CONFIG_AUDIT
@@ -9876,17 +9822,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p,
goto err;
}
#endif
-
- /*
- * Account memory _before_ installing the file descriptor. Once
- * the descriptor is installed, it can get closed at any time. Also
- * do this before hitting the general error path, as ring freeing
- * will un-account as well.
- */
- io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries),
- ACCT_LOCKED);
- ctx->limit_mem = limit_mem;
-
ret = io_allocate_scq_urings(ctx, p);
if (ret)
goto err;