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authorJens Axboe <axboe@kernel.dk>2021-02-28 01:57:30 +0300
committerJens Axboe <axboe@kernel.dk>2021-03-04 16:36:28 +0300
commit5730b27e84fdb37353c7cc2b11c24a4f9d73626e (patch)
tree52ce27bf408495f5287a8d7bba29b7e06b313386 /fs
parent1575f21a09206e914b81dace0add693346d97594 (diff)
downloadlinux-5730b27e84fdb37353c7cc2b11c24a4f9d73626e.tar.xz
io_uring: move cred assignment into io_issue_sqe()
If we move it in there, then we no longer have to care about it in io-wq. This means we can drop the cred handling in io-wq, and we can drop the REQ_F_WORK_INITIALIZED flag and async init functions as that was the last user of it since we moved to the new workers. Then we can also drop io_wq_work->creds, and just hold the personality u16 in there instead. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/io-wq.c26
-rw-r--r--fs/io-wq.h2
-rw-r--r--fs/io_uring.c75
3 files changed, 22 insertions, 81 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 1407ba74ffc3..946826beefe6 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -52,9 +52,6 @@ struct io_worker {
struct io_wq_work *cur_work;
spinlock_t lock;
- const struct cred *cur_creds;
- const struct cred *saved_creds;
-
struct completion ref_done;
struct completion started;
@@ -180,11 +177,6 @@ static void io_worker_exit(struct io_worker *worker)
worker->flags = 0;
preempt_enable();
- if (worker->saved_creds) {
- revert_creds(worker->saved_creds);
- worker->cur_creds = worker->saved_creds = NULL;
- }
-
raw_spin_lock_irq(&wqe->lock);
if (flags & IO_WORKER_F_FREE)
hlist_nulls_del_rcu(&worker->nulls_node);
@@ -326,10 +318,6 @@ static void __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
worker->flags |= IO_WORKER_F_FREE;
hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
}
- if (worker->saved_creds) {
- revert_creds(worker->saved_creds);
- worker->cur_creds = worker->saved_creds = NULL;
- }
}
static inline unsigned int io_get_work_hash(struct io_wq_work *work)
@@ -404,18 +392,6 @@ static void io_flush_signals(void)
}
}
-static void io_wq_switch_creds(struct io_worker *worker,
- struct io_wq_work *work)
-{
- const struct cred *old_creds = override_creds(work->creds);
-
- worker->cur_creds = work->creds;
- if (worker->saved_creds)
- put_cred(old_creds); /* creds set by previous switch */
- else
- worker->saved_creds = old_creds;
-}
-
static void io_assign_current_work(struct io_worker *worker,
struct io_wq_work *work)
{
@@ -465,8 +441,6 @@ get_next:
unsigned int hash = io_get_work_hash(work);
next_hashed = wq_next_work(work);
- if (work->creds && worker->cur_creds != work->creds)
- io_wq_switch_creds(worker, work);
wq->do_work(work);
io_assign_current_work(worker, NULL);
diff --git a/fs/io-wq.h b/fs/io-wq.h
index f6ef433df8a8..42f0be64a84d 100644
--- a/fs/io-wq.h
+++ b/fs/io-wq.h
@@ -79,8 +79,8 @@ static inline void wq_list_del(struct io_wq_work_list *list,
struct io_wq_work {
struct io_wq_work_node list;
- const struct cred *creds;
unsigned flags;
+ unsigned short personality;
};
static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1dd30a15ea6a..d48be0ccc590 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -688,7 +688,6 @@ enum {
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
REQ_F_NO_FILE_TABLE_BIT,
- REQ_F_WORK_INITIALIZED_BIT,
REQ_F_LTIMEOUT_ACTIVE_BIT,
REQ_F_COMPLETE_INLINE_BIT,
@@ -730,8 +729,6 @@ enum {
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
/* doesn't need file table for this request */
REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
- /* io_wq_work is initialized */
- REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT),
/* linked timeout is active, i.e. prepared by link's head */
REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT),
/* completion is deferred through io_comp_state */
@@ -1094,24 +1091,6 @@ static inline void req_set_fail_links(struct io_kiocb *req)
req->flags |= REQ_F_FAIL_LINK;
}
-static inline void __io_req_init_async(struct io_kiocb *req)
-{
- memset(&req->work, 0, sizeof(req->work));
- req->flags |= REQ_F_WORK_INITIALIZED;
-}
-
-/*
- * Note: must call io_req_init_async() for the first time you
- * touch any members of io_wq_work.
- */
-static inline void io_req_init_async(struct io_kiocb *req)
-{
- if (req->flags & REQ_F_WORK_INITIALIZED)
- return;
-
- __io_req_init_async(req);
-}
-
static void io_ring_ctx_ref_free(struct percpu_ref *ref)
{
struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
@@ -1196,13 +1175,6 @@ static bool req_need_defer(struct io_kiocb *req, u32 seq)
static void io_req_clean_work(struct io_kiocb *req)
{
- if (!(req->flags & REQ_F_WORK_INITIALIZED))
- return;
-
- if (req->work.creds) {
- put_cred(req->work.creds);
- req->work.creds = NULL;
- }
if (req->flags & REQ_F_INFLIGHT) {
struct io_ring_ctx *ctx = req->ctx;
struct io_uring_task *tctx = req->task->io_uring;
@@ -1215,8 +1187,6 @@ static void io_req_clean_work(struct io_kiocb *req)
if (atomic_read(&tctx->in_idle))
wake_up(&tctx->wait);
}
-
- req->flags &= ~REQ_F_WORK_INITIALIZED;
}
static void io_req_track_inflight(struct io_kiocb *req)
@@ -1224,7 +1194,6 @@ static void io_req_track_inflight(struct io_kiocb *req)
struct io_ring_ctx *ctx = req->ctx;
if (!(req->flags & REQ_F_INFLIGHT)) {
- io_req_init_async(req);
req->flags |= REQ_F_INFLIGHT;
spin_lock_irq(&ctx->inflight_lock);
@@ -1238,8 +1207,6 @@ static void io_prep_async_work(struct io_kiocb *req)
const struct io_op_def *def = &io_op_defs[req->opcode];
struct io_ring_ctx *ctx = req->ctx;
- io_req_init_async(req);
-
if (req->flags & REQ_F_FORCE_ASYNC)
req->work.flags |= IO_WQ_WORK_CONCURRENT;
@@ -1250,8 +1217,6 @@ static void io_prep_async_work(struct io_kiocb *req)
if (def->unbound_nonreg_file)
req->work.flags |= IO_WQ_WORK_UNBOUND;
}
- if (!req->work.creds)
- req->work.creds = get_current_cred();
}
static void io_prep_async_link(struct io_kiocb *req)
@@ -3578,7 +3543,6 @@ static int __io_splice_prep(struct io_kiocb *req,
* Splice operation will be punted aync, and here need to
* modify io_wq_work.flags, so initialize io_wq_work firstly.
*/
- io_req_init_async(req);
req->work.flags |= IO_WQ_WORK_UNBOUND;
}
@@ -5935,8 +5899,22 @@ static void __io_clean_op(struct io_kiocb *req)
static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_ring_ctx *ctx = req->ctx;
+ const struct cred *creds = NULL;
int ret;
+ if (req->work.personality) {
+ const struct cred *new_creds;
+
+ if (!(issue_flags & IO_URING_F_NONBLOCK))
+ mutex_lock(&ctx->uring_lock);
+ new_creds = idr_find(&ctx->personality_idr, req->work.personality);
+ if (!(issue_flags & IO_URING_F_NONBLOCK))
+ mutex_unlock(&ctx->uring_lock);
+ if (!new_creds)
+ return -EINVAL;
+ creds = override_creds(new_creds);
+ }
+
switch (req->opcode) {
case IORING_OP_NOP:
ret = io_nop(req, issue_flags);
@@ -6043,6 +6021,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
break;
}
+ if (creds)
+ revert_creds(creds);
+
if (ret)
return ret;
@@ -6206,18 +6187,10 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
static void __io_queue_sqe(struct io_kiocb *req)
{
struct io_kiocb *linked_timeout = io_prep_linked_timeout(req);
- const struct cred *old_creds = NULL;
int ret;
- if ((req->flags & REQ_F_WORK_INITIALIZED) && req->work.creds &&
- req->work.creds != current_cred())
- old_creds = override_creds(req->work.creds);
-
ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);
- if (old_creds)
- revert_creds(old_creds);
-
/*
* We async punt it if the file wasn't marked NOWAIT, or if the file
* doesn't support non-blocking read/write attempts
@@ -6304,7 +6277,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
{
struct io_submit_state *state;
unsigned int sqe_flags;
- int id, ret = 0;
+ int ret = 0;
req->opcode = READ_ONCE(sqe->opcode);
/* same numerical values with corresponding REQ_F_*, safe to copy */
@@ -6336,15 +6309,9 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
!io_op_defs[req->opcode].buffer_select)
return -EOPNOTSUPP;
- id = READ_ONCE(sqe->personality);
- if (id) {
- __io_req_init_async(req);
- req->work.creds = idr_find(&ctx->personality_idr, id);
- if (unlikely(!req->work.creds))
- return -EINVAL;
- get_cred(req->work.creds);
- }
-
+ req->work.list.next = NULL;
+ req->work.flags = 0;
+ req->work.personality = READ_ONCE(sqe->personality);
state = &ctx->submit_state;
/*