io_uring: modularize io_sqe_buffer_register
Split io_sqe_buffer_register into two routines:
- io_sqe_buffer_register() registers a single buffer
- io_sqe_buffers_register iterates over all user specified buffers
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index fbc6d2f..ec70ba0 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8370,7 +8370,7 @@ static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
return pages;
}
-static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
+static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
{
int i, j;
@@ -8488,14 +8488,103 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
return ret;
}
-static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
- unsigned nr_args)
+static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
+ struct io_mapped_ubuf *imu,
+ struct page **last_hpage)
{
struct vm_area_struct **vmas = NULL;
struct page **pages = NULL;
+ unsigned long off, start, end, ubuf;
+ size_t size;
+ int ret, pret, nr_pages, i;
+
+ ubuf = (unsigned long) iov->iov_base;
+ end = (ubuf + iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ start = ubuf >> PAGE_SHIFT;
+ nr_pages = end - start;
+
+ ret = -ENOMEM;
+
+ pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ goto done;
+
+ vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
+ GFP_KERNEL);
+ if (!vmas)
+ goto done;
+
+ imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
+ GFP_KERNEL);
+ if (!imu->bvec)
+ goto done;
+
+ ret = 0;
+ mmap_read_lock(current->mm);
+ pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
+ pages, vmas);
+ if (pret == nr_pages) {
+ /* don't support file backed memory */
+ for (i = 0; i < nr_pages; i++) {
+ struct vm_area_struct *vma = vmas[i];
+
+ if (vma->vm_file &&
+ !is_file_hugepages(vma->vm_file)) {
+ ret = -EOPNOTSUPP;
+ break;
+ }
+ }
+ } else {
+ ret = pret < 0 ? pret : -EFAULT;
+ }
+ mmap_read_unlock(current->mm);
+ if (ret) {
+ /*
+ * if we did partial map, or found file backed vmas,
+ * release any pages we did get
+ */
+ if (pret > 0)
+ unpin_user_pages(pages, pret);
+ kvfree(imu->bvec);
+ goto done;
+ }
+
+ ret = io_buffer_account_pin(ctx, pages, pret, imu, last_hpage);
+ if (ret) {
+ unpin_user_pages(pages, pret);
+ kvfree(imu->bvec);
+ goto done;
+ }
+
+ off = ubuf & ~PAGE_MASK;
+ size = iov->iov_len;
+ for (i = 0; i < nr_pages; i++) {
+ size_t vec_len;
+
+ vec_len = min_t(size_t, size, PAGE_SIZE - off);
+ imu->bvec[i].bv_page = pages[i];
+ imu->bvec[i].bv_len = vec_len;
+ imu->bvec[i].bv_offset = off;
+ off = 0;
+ size -= vec_len;
+ }
+ /* store original address for later verification */
+ imu->ubuf = ubuf;
+ imu->len = iov->iov_len;
+ imu->nr_bvecs = nr_pages;
+ ret = 0;
+done:
+ kvfree(pages);
+ kvfree(vmas);
+ return ret;
+}
+
+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;
- int i, j, got_pages = 0;
- int ret = -EINVAL;
if (ctx->user_bufs)
return -EBUSY;
@@ -8509,14 +8598,10 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
for (i = 0; i < nr_args; i++) {
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
- unsigned long off, start, end, ubuf;
- int pret, nr_pages;
- struct iovec iov;
- size_t size;
ret = io_copy_iov(ctx, &iov, arg, i);
if (ret)
- goto err;
+ break;
/*
* Don't impose further limits on the size and buffer
@@ -8525,103 +8610,22 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
*/
ret = -EFAULT;
if (!iov.iov_base || !iov.iov_len)
- goto err;
+ break;
/* arbitrary limit, but we need something */
if (iov.iov_len > SZ_1G)
- goto err;
+ break;
- ubuf = (unsigned long) iov.iov_base;
- end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- start = ubuf >> PAGE_SHIFT;
- nr_pages = end - start;
-
- ret = 0;
- if (!pages || nr_pages > got_pages) {
- kvfree(vmas);
- kvfree(pages);
- pages = kvmalloc_array(nr_pages, sizeof(struct page *),
- GFP_KERNEL);
- vmas = kvmalloc_array(nr_pages,
- sizeof(struct vm_area_struct *),
- GFP_KERNEL);
- if (!pages || !vmas) {
- ret = -ENOMEM;
- goto err;
- }
- got_pages = nr_pages;
- }
-
- imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
- GFP_KERNEL);
- ret = -ENOMEM;
- if (!imu->bvec)
- goto err;
-
- ret = 0;
- mmap_read_lock(current->mm);
- pret = pin_user_pages(ubuf, nr_pages,
- FOLL_WRITE | FOLL_LONGTERM,
- pages, vmas);
- if (pret == nr_pages) {
- /* don't support file backed memory */
- for (j = 0; j < nr_pages; j++) {
- struct vm_area_struct *vma = vmas[j];
-
- if (vma->vm_file &&
- !is_file_hugepages(vma->vm_file)) {
- ret = -EOPNOTSUPP;
- break;
- }
- }
- } else {
- ret = pret < 0 ? pret : -EFAULT;
- }
- mmap_read_unlock(current->mm);
- if (ret) {
- /*
- * if we did partial map, or found file backed vmas,
- * release any pages we did get
- */
- if (pret > 0)
- unpin_user_pages(pages, pret);
- kvfree(imu->bvec);
- goto err;
- }
-
- ret = io_buffer_account_pin(ctx, pages, pret, imu, &last_hpage);
- if (ret) {
- unpin_user_pages(pages, pret);
- kvfree(imu->bvec);
- goto err;
- }
-
- off = ubuf & ~PAGE_MASK;
- size = iov.iov_len;
- for (j = 0; j < nr_pages; j++) {
- size_t vec_len;
-
- vec_len = min_t(size_t, size, PAGE_SIZE - off);
- imu->bvec[j].bv_page = pages[j];
- imu->bvec[j].bv_len = vec_len;
- imu->bvec[j].bv_offset = off;
- off = 0;
- size -= vec_len;
- }
- /* store original address for later verification */
- imu->ubuf = ubuf;
- imu->len = iov.iov_len;
- imu->nr_bvecs = nr_pages;
+ ret = io_sqe_buffer_register(ctx, &iov, imu, &last_hpage);
+ if (ret)
+ break;
ctx->nr_user_bufs++;
}
- kvfree(pages);
- kvfree(vmas);
- return 0;
-err:
- kvfree(pages);
- kvfree(vmas);
- io_sqe_buffer_unregister(ctx);
+
+ if (ret)
+ io_sqe_buffers_unregister(ctx);
+
return ret;
}
@@ -8675,7 +8679,7 @@ static void io_destroy_buffers(struct io_ring_ctx *ctx)
static void io_ring_ctx_free(struct io_ring_ctx *ctx)
{
io_finish_async(ctx);
- io_sqe_buffer_unregister(ctx);
+ io_sqe_buffers_unregister(ctx);
if (ctx->sqo_task) {
put_task_struct(ctx->sqo_task);
@@ -10057,13 +10061,13 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
switch (opcode) {
case IORING_REGISTER_BUFFERS:
- ret = io_sqe_buffer_register(ctx, arg, nr_args);
+ ret = io_sqe_buffers_register(ctx, arg, nr_args);
break;
case IORING_UNREGISTER_BUFFERS:
ret = -EINVAL;
if (arg || nr_args)
break;
- ret = io_sqe_buffer_unregister(ctx);
+ ret = io_sqe_buffers_unregister(ctx);
break;
case IORING_REGISTER_FILES:
ret = io_sqe_files_register(ctx, arg, nr_args);
