From 09ab7eff38202159271534d2f5ad45526168f2a5 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 14 Mar 2024 10:45:07 -0600 Subject: [PATCH] io_uring/kbuf: get rid of lower BGID lists Just rely on the xarray for any kind of bgid. This simplifies things, and it really doesn't bring us much, if anything. Cc: stable@vger.kernel.org # v6.4+ Signed-off-by: Jens Axboe --- include/linux/io_uring_types.h | 1 - io_uring/io_uring.c | 2 - io_uring/kbuf.c | 70 ++++------------------------------ 3 files changed, 8 insertions(+), 65 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index e24893625085..05df0e399d7c 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -294,7 +294,6 @@ struct io_ring_ctx { struct io_submit_state submit_state; - struct io_buffer_list *io_bl; struct xarray io_bl_xa; struct io_hash_table cancel_table_locked; diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index d1defb99b89e..bc730f59265f 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -351,7 +351,6 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) err: kfree(ctx->cancel_table.hbs); kfree(ctx->cancel_table_locked.hbs); - kfree(ctx->io_bl); xa_destroy(&ctx->io_bl_xa); kfree(ctx); return NULL; @@ -2932,7 +2931,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx) io_napi_free(ctx); kfree(ctx->cancel_table.hbs); kfree(ctx->cancel_table_locked.hbs); - kfree(ctx->io_bl); xa_destroy(&ctx->io_bl_xa); kfree(ctx); } diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 693c26da4ee1..8bf0121f00af 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -17,8 +17,6 @@ #define IO_BUFFER_LIST_BUF_PER_PAGE (PAGE_SIZE / sizeof(struct io_uring_buf)) -#define BGID_ARRAY 64 - /* BIDs are addressed by a 16-bit field in a CQE */ #define MAX_BIDS_PER_BGID (1 << 16) @@ -40,13 +38,9 @@ struct io_buf_free { int inuse; }; -static struct io_buffer_list *__io_buffer_get_list(struct io_ring_ctx *ctx, - struct io_buffer_list *bl, - unsigned int bgid) +static inline struct io_buffer_list *__io_buffer_get_list(struct io_ring_ctx *ctx, + unsigned int bgid) { - if (bl && bgid < BGID_ARRAY) - return &bl[bgid]; - return xa_load(&ctx->io_bl_xa, bgid); } @@ -55,7 +49,7 @@ static inline struct io_buffer_list *io_buffer_get_list(struct io_ring_ctx *ctx, { lockdep_assert_held(&ctx->uring_lock); - return __io_buffer_get_list(ctx, ctx->io_bl, bgid); + return __io_buffer_get_list(ctx, bgid); } static int io_buffer_add_list(struct io_ring_ctx *ctx, @@ -68,10 +62,6 @@ static int io_buffer_add_list(struct io_ring_ctx *ctx, */ bl->bgid = bgid; smp_store_release(&bl->is_ready, 1); - - if (bgid < BGID_ARRAY) - return 0; - return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL)); } @@ -208,24 +198,6 @@ void __user *io_buffer_select(struct io_kiocb *req, size_t *len, return ret; } -static __cold int io_init_bl_list(struct io_ring_ctx *ctx) -{ - struct io_buffer_list *bl; - int i; - - bl = kcalloc(BGID_ARRAY, sizeof(struct io_buffer_list), GFP_KERNEL); - if (!bl) - return -ENOMEM; - - for (i = 0; i < BGID_ARRAY; i++) { - INIT_LIST_HEAD(&bl[i].buf_list); - bl[i].bgid = i; - } - - smp_store_release(&ctx->io_bl, bl); - return 0; -} - /* * Mark the given mapped range as free for reuse */ @@ -300,13 +272,6 @@ void io_destroy_buffers(struct io_ring_ctx *ctx) struct list_head *item, *tmp; struct io_buffer *buf; unsigned long index; - int i; - - for (i = 0; i < BGID_ARRAY; i++) { - if (!ctx->io_bl) - break; - __io_remove_buffers(ctx, &ctx->io_bl[i], -1U); - } xa_for_each(&ctx->io_bl_xa, index, bl) { xa_erase(&ctx->io_bl_xa, bl->bgid); @@ -489,12 +454,6 @@ int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags) io_ring_submit_lock(ctx, issue_flags); - if (unlikely(p->bgid < BGID_ARRAY && !ctx->io_bl)) { - ret = io_init_bl_list(ctx); - if (ret) - goto err; - } - bl = io_buffer_get_list(ctx, p->bgid); if (unlikely(!bl)) { bl = kzalloc(sizeof(*bl), GFP_KERNEL_ACCOUNT); @@ -507,14 +466,9 @@ int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags) if (ret) { /* * Doesn't need rcu free as it was never visible, but - * let's keep it consistent throughout. Also can't - * be a lower indexed array group, as adding one - * where lookup failed cannot happen. + * let's keep it consistent throughout. */ - if (p->bgid >= BGID_ARRAY) - kfree_rcu(bl, rcu); - else - WARN_ON_ONCE(1); + kfree_rcu(bl, rcu); goto err; } } @@ -679,12 +633,6 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) if (reg.ring_entries >= 65536) return -EINVAL; - if (unlikely(reg.bgid < BGID_ARRAY && !ctx->io_bl)) { - int ret = io_init_bl_list(ctx); - if (ret) - return ret; - } - bl = io_buffer_get_list(ctx, reg.bgid); if (bl) { /* if mapped buffer ring OR classic exists, don't allow */ @@ -734,10 +682,8 @@ int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) return -EINVAL; __io_remove_buffers(ctx, bl, -1U); - if (bl->bgid >= BGID_ARRAY) { - xa_erase(&ctx->io_bl_xa, bl->bgid); - kfree_rcu(bl, rcu); - } + xa_erase(&ctx->io_bl_xa, bl->bgid); + kfree_rcu(bl, rcu); return 0; } @@ -771,7 +717,7 @@ void *io_pbuf_get_address(struct io_ring_ctx *ctx, unsigned long bgid) { struct io_buffer_list *bl; - bl = __io_buffer_get_list(ctx, smp_load_acquire(&ctx->io_bl), bgid); + bl = __io_buffer_get_list(ctx, bgid); if (!bl || !bl->is_mmap) return NULL;