From: Hao Xu <[email protected]>
To: Jens Axboe <[email protected]>, [email protected]
Cc: [email protected]
Subject: Re: [PATCH 1/4] io_uring: track fixed files with a bitmap
Date: Mon, 9 May 2022 21:26:52 +0800 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
在 2022/5/9 上午7:49, Jens Axboe 写道:
> In preparation for adding a basic allocator for direct descriptors,
> add helpers that set/clear whether a file slot is used.
>
> Signed-off-by: Jens Axboe <[email protected]>
> ---
> fs/io_uring.c | 37 +++++++++++++++++++++++++++++++++++--
> 1 file changed, 35 insertions(+), 2 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index b6d491c9a25f..6eac6629e7d4 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -257,6 +257,7 @@ struct io_rsrc_put {
>
> struct io_file_table {
> struct io_fixed_file *files;
> + unsigned long *bitmap;
> };
>
> struct io_rsrc_node {
> @@ -7573,6 +7574,7 @@ static inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
> /* mask in overlapping REQ_F and FFS bits */
> req->flags |= (file_ptr << REQ_F_SUPPORT_NOWAIT_BIT);
> io_req_set_rsrc_node(req, ctx, 0);
> + WARN_ON_ONCE(file && !test_bit(fd, ctx->file_table.bitmap));
> out:
> io_ring_submit_unlock(ctx, issue_flags);
> return file;
> @@ -8639,13 +8641,35 @@ static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
> {
> table->files = kvcalloc(nr_files, sizeof(table->files[0]),
> GFP_KERNEL_ACCOUNT);
> - return !!table->files;
> + if (unlikely(!table->files))
> + return false;
> +
> + table->bitmap = bitmap_zalloc(nr_files, GFP_KERNEL_ACCOUNT);
> + if (unlikely(!table->bitmap)) {
> + kvfree(table->files);
> + return false;
> + }
> +
> + return true;
> }
>
> static void io_free_file_tables(struct io_file_table *table)
> {
> kvfree(table->files);
> + bitmap_free(table->bitmap);
> table->files = NULL;
> + table->bitmap = NULL;
> +}
> +
> +static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
> +{
> + WARN_ON_ONCE(test_bit(bit, table->bitmap));
> + __set_bit(bit, table->bitmap);
> +}
> +
> +static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
> +{
> + __clear_bit(bit, table->bitmap);
> }
>
> static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
> @@ -8660,6 +8684,7 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
> continue;
> if (io_fixed_file_slot(&ctx->file_table, i)->file_ptr & FFS_SCM)
> continue;
> + io_file_bitmap_clear(&ctx->file_table, i);
> fput(file);
> }
> #endif
> @@ -9063,6 +9088,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
> }
> 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);
> }
>
> io_rsrc_node_switch(ctx, NULL);
> @@ -9123,6 +9149,7 @@ static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
> if (ret)
> goto err;
> file_slot->file_ptr = 0;
> + io_file_bitmap_clear(&ctx->file_table, slot_index);
> needs_switch = true;
> }
>
> @@ -9130,13 +9157,16 @@ static int io_install_fixed_file(struct io_kiocb *req, struct file *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);
[1]
> }
> err:
> if (needs_switch)
> io_rsrc_node_switch(ctx, ctx->file_data);
> io_ring_submit_unlock(ctx, issue_flags);
> - if (ret)
> + if (ret) {
> + io_file_bitmap_clear(&ctx->file_table, slot_index);
We don't need to clean it, since we get here only when we didn't
run [1], which means we haven't set it.
> fput(file);
> + }
> return ret;
> }
>
next prev parent reply other threads:[~2022-05-09 13:26 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-08 23:49 [PATCHSET 0/4] Allow allocated direct descriptors Jens Axboe
2022-05-08 23:49 ` [PATCH 1/4] io_uring: track fixed files with a bitmap Jens Axboe
2022-05-09 13:26 ` Hao Xu [this message]
2022-05-09 14:55 ` Jens Axboe
2022-05-08 23:49 ` [PATCH 2/4] io_uring: add basic fixed file allocator Jens Axboe
2022-05-08 23:49 ` [PATCH 3/4] io_uring: allow allocated fixed files for openat/openat2 Jens Axboe
2022-05-08 23:49 ` [PATCH 4/4] io_uring: allow allocated fixed files for accept Jens Axboe
2022-05-09 13:20 ` [PATCHSET 0/4] Allow allocated direct descriptors Hao Xu
2022-05-09 14:49 ` Jens Axboe
2022-05-10 5:35 ` Hao Xu
2022-05-10 12:26 ` Jens Axboe
2022-06-10 13:41 ` Victor Stewart
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