Apply fixed_rsrc functionality for fixed buffers support.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@xxxxxxxxxx>
---
fs/io_uring.c | 221 ++++++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 183 insertions(+), 38 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 416c350..2f02e11 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -104,6 +104,14 @@
#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
IORING_REGISTER_LAST + IORING_OP_LAST)
+/*
+ * Shift of 7 is 128 entries, or exactly one page on 64-bit archs
+ */
+#define IORING_BUF_TABLE_SHIFT 7 /* struct io_mapped_ubuf */
+#define IORING_MAX_BUFS_TABLE (1U << IORING_BUF_TABLE_SHIFT)
+#define IORING_BUF_TABLE_MASK (IORING_MAX_BUFS_TABLE - 1)
+#define IORING_MAX_FIXED_BUFS UIO_MAXIOV
+
struct io_uring {
u32 head ____cacheline_aligned_in_smp;
u32 tail ____cacheline_aligned_in_smp;
@@ -202,11 +210,15 @@ struct io_rsrc_put {
union {
void *rsrc;
struct file *file;
+ struct io_mapped_ubuf *buf;
};
};
struct fixed_rsrc_table {
- struct file **files;
+ union {
+ struct file **files;
+ struct io_mapped_ubuf *bufs;
+ };
};
struct fixed_rsrc_ref_node {
@@ -333,8 +345,8 @@ struct io_ring_ctx {
unsigned nr_user_files;
/* if used, fixed mapped user buffers */
+ struct fixed_rsrc_data *buf_data;
unsigned nr_user_bufs;
- struct io_mapped_ubuf *user_bufs;
struct user_struct *user;
@@ -1015,6 +1027,8 @@ static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node(
struct io_ring_ctx *ctx);
static void init_fixed_file_ref_node(struct io_ring_ctx *ctx,
struct fixed_rsrc_ref_node *ref_node);
+static void init_fixed_buf_ref_node(struct io_ring_ctx *ctx,
+ struct fixed_rsrc_ref_node *ref_node);
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
struct io_comp_state *cs);
@@ -2988,6 +3002,15 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
io_rw_done(kiocb, ret);
}
+static inline struct io_mapped_ubuf *io_buf_from_index(struct io_ring_ctx *ctx,
+ int index)
+{
+ struct fixed_rsrc_table *table;
+
+ table = &ctx->buf_data->table[index >> IORING_BUF_TABLE_SHIFT];
+ return &table->bufs[index & IORING_BUF_TABLE_MASK];
+}
+
static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
struct iov_iter *iter)
{
@@ -3001,7 +3024,7 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
if (unlikely(buf_index >= ctx->nr_user_bufs))
return -EFAULT;
index = array_index_nospec(buf_index, ctx->nr_user_bufs);
- imu = &ctx->user_bufs[index];
+ imu = io_buf_from_index(ctx, index);
buf_addr = req->rw.addr;
/* overflow */
@@ -6086,7 +6109,7 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
req->opcode);
- return-EINVAL;
+ return -EINVAL;
}
static int io_req_defer_prep(struct io_kiocb *req,
@@ -8391,28 +8414,66 @@ static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
return pages;
}
-static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf *imu)
{
- int i, j;
+ unsigned int i;
- if (!ctx->user_bufs)
- return -ENXIO;
+ for (i = 0; i < imu->nr_bvecs; i++)
+ unpin_user_page(imu->bvec[i].bv_page);
- for (i = 0; i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
+ if (imu->acct_pages)
+ io_unaccount_mem(ctx, imu->nr_bvecs, ACCT_PINNED);
+ kvfree(imu->bvec);
+ imu->nr_bvecs = 0;
+}
- for (j = 0; j < imu->nr_bvecs; j++)
- unpin_user_page(imu->bvec[j].bv_page);
+static void io_buffers_unmap(struct io_ring_ctx *ctx)
+{
+ unsigned int i;
+ struct io_mapped_ubuf *imu;
- if (imu->acct_pages)
- io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED);
- kvfree(imu->bvec);
- imu->nr_bvecs = 0;
+ for (i = 0; i < ctx->nr_user_bufs; i++) {
+ imu = io_buf_from_index(ctx, i);
+ io_buffer_unmap(ctx, imu);
}
+}
- kfree(ctx->user_bufs);
- ctx->user_bufs = NULL;
+static void io_buffers_map_free(struct io_ring_ctx *ctx)
+{
+ struct fixed_rsrc_data *data = ctx->buf_data;
+ unsigned int nr_tables, i;
+
+ if (!data)
+ return;
+
+ nr_tables = DIV_ROUND_UP(ctx->nr_user_bufs, IORING_MAX_BUFS_TABLE);
+ for (i = 0; i < nr_tables; i++)
+ kfree(data->table[i].bufs);
+ free_fixed_rsrc_data(data);
+ ctx->buf_data = NULL;
ctx->nr_user_bufs = 0;
+}
+
+static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ struct fixed_rsrc_data *data = ctx->buf_data;
+ struct fixed_rsrc_ref_node *backup_node;
+ int ret;
+
+ if (!data)
+ return -ENXIO;
+ backup_node = alloc_fixed_rsrc_ref_node(ctx);
+ if (!backup_node)
+ return -ENOMEM;
+ init_fixed_buf_ref_node(ctx, backup_node);
+
+ ret = io_rsrc_ref_quiesce(data, ctx, backup_node);
+ if (ret)
+ return ret;
+
+ io_buffers_unmap(ctx);
+ io_buffers_map_free(ctx);
+
return 0;
}
@@ -8465,7 +8526,9 @@ static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
/* check previously registered pages */
for (i = 0; i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
+ struct io_mapped_ubuf *imu;
+
+ imu = io_buf_from_index(ctx, i);
for (j = 0; j < imu->nr_bvecs; j++) {
if (!PageCompound(imu->bvec[j].bv_page))
@@ -8600,19 +8663,66 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
return ret;
}
-static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
+static void io_free_buf_tables(struct fixed_rsrc_data *buf_data,
+ unsigned int nr_tables)
{
- if (ctx->user_bufs)
- return -EBUSY;
- if (!nr_args || nr_args > UIO_MAXIOV)
- return -EINVAL;
+ int i;
- ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
- GFP_KERNEL);
- if (!ctx->user_bufs)
- return -ENOMEM;
+ for (i = 0; i < nr_tables; i++) {
+ struct fixed_rsrc_table *table = &buf_data->table[i];
- return 0;
+ kfree(table->bufs);
+ }
+}
+
+static int io_alloc_buf_tables(struct fixed_rsrc_data *buf_data,
+ unsigned int nr_tables, unsigned int nr_bufs)
+{
+ int i;
+
+ for (i = 0; i < nr_tables; i++) {
+ struct fixed_rsrc_table *table = &buf_data->table[i];
+ unsigned int this_bufs;
+
+ this_bufs = min(nr_bufs, IORING_MAX_BUFS_TABLE);
+ table->bufs = kcalloc(this_bufs, sizeof(struct io_mapped_ubuf),
+ GFP_KERNEL);
+ if (!table->bufs)
+ break;
+ nr_bufs -= this_bufs;
+ }
+
+ if (i == nr_tables)
+ return 0;
+
+ io_free_buf_tables(buf_data, i);
+ return 1;
+}
+
+static struct fixed_rsrc_data *io_buffers_map_alloc(struct io_ring_ctx *ctx,
+ unsigned int nr_args)
+{
+ unsigned int nr_tables;
+ struct fixed_rsrc_data *buf_data;
+
+ buf_data = alloc_fixed_rsrc_data(ctx);
+ if (!buf_data)
+ return NULL;
+
+ nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_BUFS_TABLE);
+ buf_data->table = kcalloc(nr_tables, sizeof(*buf_data->table),
+ GFP_KERNEL);
+ if (!buf_data->table)
+ goto out;
+
+ if (io_alloc_buf_tables(buf_data, nr_tables, nr_args))
+ goto out;
+
+ return buf_data;
+out:
+ free_fixed_rsrc_data(ctx->buf_data);
+ ctx->buf_data = NULL;
+ return NULL;
}
static int io_buffer_validate(struct iovec *iov)
@@ -8632,39 +8742,73 @@ static int io_buffer_validate(struct iovec *iov)
return 0;
}
+static void io_ring_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ io_buffer_unmap(ctx, prsrc->buf);
+}
+
+static void init_fixed_buf_ref_node(struct io_ring_ctx *ctx,
+ struct fixed_rsrc_ref_node *ref_node)
+{
+ ref_node->rsrc_data = ctx->buf_data;
+ ref_node->rsrc_put = io_ring_buf_put;
+}
+
static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned int nr_args)
{
int i, ret;
struct iovec iov;
struct page *last_hpage = NULL;
+ struct fixed_rsrc_ref_node *ref_node;
+ struct fixed_rsrc_data *buf_data;
- ret = io_buffers_map_alloc(ctx, nr_args);
- if (ret)
- return ret;
+ if (ctx->buf_data)
+ return -EBUSY;
+ if (!nr_args || nr_args > IORING_MAX_FIXED_BUFS)
+ return -EINVAL;
- for (i = 0; i < nr_args; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
+ buf_data = io_buffers_map_alloc(ctx, nr_args);
+ if (!buf_data)
+ return -ENOMEM;
+ ctx->buf_data = buf_data;
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
+ struct io_mapped_ubuf *imu;
ret = io_copy_iov(ctx, &iov, arg, i);
if (ret)
break;
+ /* allow sparse sets */
+ if (!iov.iov_base && !iov.iov_len)
+ continue;
+
ret = io_buffer_validate(&iov);
if (ret)
break;
+ imu = io_buf_from_index(ctx, i);
+
ret = io_sqe_buffer_register(ctx, &iov, imu, &last_hpage);
if (ret)
break;
+ }
- ctx->nr_user_bufs++;
+ if (ret) {
+ io_sqe_buffers_unregister(ctx);
+ return ret;
}
- if (ret)
+ ref_node = alloc_fixed_rsrc_ref_node(ctx);
+ if (!ref_node) {
io_sqe_buffers_unregister(ctx);
+ return -ENOMEM;
+ }
+ init_fixed_buf_ref_node(ctx, ref_node);
- return ret;
+ io_sqe_rsrc_set_node(ctx, buf_data, ref_node);
+ return 0;
}
static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
@@ -9508,7 +9652,7 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
}
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
+ struct io_mapped_ubuf *buf = io_buf_from_index(ctx, i);
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
(unsigned int) buf->len);
@@ -10025,6 +10169,7 @@ static bool io_register_op_must_quiesce(int op)
switch (op) {
case IORING_UNREGISTER_FILES:
case IORING_REGISTER_FILES_UPDATE:
+ case IORING_UNREGISTER_BUFFERS:
case IORING_REGISTER_PROBE:
case IORING_REGISTER_PERSONALITY:
case IORING_UNREGISTER_PERSONALITY:
--
1.8.3.1
