This is in preparation for adding opcodes that need to modify files in a process file table, either adding new ones or closing old ones.
If an opcode needs this, it must set REQ_F_NEED_FILES in the request structure. If work that needs to get punted to async context have this set, they will grab a reference to the process file table. When the work is completed, the reference is dropped again. Signed-off-by: Jens Axboe <[email protected]> --- fs/io_uring.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 635856023fdf..ad462237275e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -267,10 +267,11 @@ struct io_ring_ctx { struct sqe_submit { const struct io_uring_sqe *sqe; unsigned short index; + bool has_user : 1; + bool in_async : 1; + bool needs_fixed_file : 1; u32 sequence; - bool has_user; - bool in_async; - bool needs_fixed_file; + struct files_struct *files; }; /* @@ -323,6 +324,7 @@ struct io_kiocb { #define REQ_F_FAIL_LINK 256 /* fail rest of links */ #define REQ_F_SHADOW_DRAIN 512 /* link-drain shadow req */ #define REQ_F_TIMEOUT 1024 /* timeout request */ +#define REQ_F_NEED_FILES 2048 /* needs to assume file table */ u64 user_data; u32 result; u32 sequence; @@ -2191,6 +2193,7 @@ static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) static void io_sq_wq_submit_work(struct work_struct *work) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct files_struct *old_files = NULL; struct io_ring_ctx *ctx = req->ctx; struct mm_struct *cur_mm = NULL; struct async_list *async_list; @@ -2220,6 +2223,10 @@ static void io_sq_wq_submit_work(struct work_struct *work) set_fs(USER_DS); } } + if (s->files && !old_files) { + old_files = current->files; + current->files = s->files; + } if (!ret) { s->has_user = cur_mm != NULL; @@ -2312,6 +2319,11 @@ static void io_sq_wq_submit_work(struct work_struct *work) unuse_mm(cur_mm); mmput(cur_mm); } + if (old_files) { + struct files_struct *files = current->files; + current->files = old_files; + put_files_struct(files); + } } /* @@ -2413,6 +2425,8 @@ static int __io_queue_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, s->sqe = sqe_copy; memcpy(&req->submit, s, sizeof(*s)); + if (req->flags & REQ_F_NEED_FILES) + req->submit.files = get_files_struct(current); list = io_async_list_from_sqe(ctx, s->sqe); if (!io_add_to_prev_work(list, req)) { if (list) @@ -2633,6 +2647,7 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) s->index = head; s->sqe = &ctx->sq_sqes[head]; s->sequence = ctx->cached_sq_head; + s->files = NULL; ctx->cached_sq_head++; return true; } -- 2.17.1
