Merge tag 'for-4.21/aio-20181221' of git://git.kernel.dk/linux-block
Pull aio updates from Jens Axboe:
"Flushing out pre-patches for the buffered/polled aio series. Some
fixes in here, but also optimizations"
* tag 'for-4.21/aio-20181221' of git://git.kernel.dk/linux-block:
aio: abstract out io_event filler helper
aio: split out iocb copy from io_submit_one()
aio: use iocb_put() instead of open coding it
aio: only use blk plugs for > 2 depth submissions
aio: don't zero entire aio_kiocb aio_get_req()
aio: separate out ring reservation from req allocation
aio: use assigned completion handler
diff --git a/fs/aio.c b/fs/aio.c
index 0f99cad..43c508f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -70,6 +70,12 @@
struct io_event io_events[0];
}; /* 128 bytes + ring size */
+/*
+ * Plugging is meant to work with larger batches of IOs. If we don't
+ * have more than the below, then don't bother setting up a plug.
+ */
+#define AIO_PLUG_THRESHOLD 2
+
#define AIO_RING_PAGES 8
struct kioctx_table {
@@ -902,7 +908,7 @@
local_irq_restore(flags);
}
-static bool get_reqs_available(struct kioctx *ctx)
+static bool __get_reqs_available(struct kioctx *ctx)
{
struct kioctx_cpu *kcpu;
bool ret = false;
@@ -994,6 +1000,14 @@
spin_unlock_irq(&ctx->completion_lock);
}
+static bool get_reqs_available(struct kioctx *ctx)
+{
+ if (__get_reqs_available(ctx))
+ return true;
+ user_refill_reqs_available(ctx);
+ return __get_reqs_available(ctx);
+}
+
/* aio_get_req
* Allocate a slot for an aio request.
* Returns NULL if no requests are free.
@@ -1002,24 +1016,16 @@
{
struct aio_kiocb *req;
- if (!get_reqs_available(ctx)) {
- user_refill_reqs_available(ctx);
- if (!get_reqs_available(ctx))
- return NULL;
- }
-
- req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
+ req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
if (unlikely(!req))
- goto out_put;
+ return NULL;
percpu_ref_get(&ctx->reqs);
+ req->ki_ctx = ctx;
INIT_LIST_HEAD(&req->ki_list);
refcount_set(&req->ki_refcnt, 0);
- req->ki_ctx = ctx;
+ req->ki_eventfd = NULL;
return req;
-out_put:
- put_reqs_available(ctx, 1);
- return NULL;
}
static struct kioctx *lookup_ioctx(unsigned long ctx_id)
@@ -1059,6 +1065,15 @@
}
}
+static void aio_fill_event(struct io_event *ev, struct aio_kiocb *iocb,
+ long res, long res2)
+{
+ ev->obj = (u64)(unsigned long)iocb->ki_user_iocb;
+ ev->data = iocb->ki_user_data;
+ ev->res = res;
+ ev->res2 = res2;
+}
+
/* aio_complete
* Called when the io request on the given iocb is complete.
*/
@@ -1086,10 +1101,7 @@
ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
event = ev_page + pos % AIO_EVENTS_PER_PAGE;
- event->obj = (u64)(unsigned long)iocb->ki_user_iocb;
- event->data = iocb->ki_user_data;
- event->res = res;
- event->res2 = res2;
+ aio_fill_event(event, iocb, res, res2);
kunmap_atomic(ev_page);
flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
@@ -1416,7 +1428,7 @@
aio_complete(iocb, res, res2);
}
-static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)
+static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
{
int ret;
@@ -1457,7 +1469,7 @@
return ret;
}
-static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec,
+static int aio_setup_rw(int rw, const struct iocb *iocb, struct iovec **iovec,
bool vectored, bool compat, struct iov_iter *iter)
{
void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
@@ -1492,12 +1504,12 @@
ret = -EINTR;
/*FALLTHRU*/
default:
- aio_complete_rw(req, ret, 0);
+ req->ki_complete(req, ret, 0);
}
}
-static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored,
- bool compat)
+static ssize_t aio_read(struct kiocb *req, const struct iocb *iocb,
+ bool vectored, bool compat)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct iov_iter iter;
@@ -1529,8 +1541,8 @@
return ret;
}
-static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
- bool compat)
+static ssize_t aio_write(struct kiocb *req, const struct iocb *iocb,
+ bool vectored, bool compat)
{
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct iov_iter iter;
@@ -1585,7 +1597,8 @@
aio_complete(container_of(req, struct aio_kiocb, fsync), ret, 0);
}
-static int aio_fsync(struct fsync_iocb *req, struct iocb *iocb, bool datasync)
+static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
+ bool datasync)
{
if (unlikely(iocb->aio_buf || iocb->aio_offset || iocb->aio_nbytes ||
iocb->aio_rw_flags))
@@ -1713,7 +1726,7 @@
add_wait_queue(head, &pt->iocb->poll.wait);
}
-static ssize_t aio_poll(struct aio_kiocb *aiocb, struct iocb *iocb)
+static ssize_t aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)
{
struct kioctx *ctx = aiocb->ki_ctx;
struct poll_iocb *req = &aiocb->poll;
@@ -1733,6 +1746,10 @@
if (unlikely(!req->file))
return -EBADF;
+ req->head = NULL;
+ req->woken = false;
+ req->cancelled = false;
+
apt.pt._qproc = aio_poll_queue_proc;
apt.pt._key = req->events;
apt.iocb = aiocb;
@@ -1781,44 +1798,44 @@
return 0;
}
-static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
- bool compat)
+static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
+ struct iocb __user *user_iocb, bool compat)
{
struct aio_kiocb *req;
- struct iocb iocb;
ssize_t ret;
- if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb))))
- return -EFAULT;
-
/* enforce forwards compatibility on users */
- if (unlikely(iocb.aio_reserved2)) {
+ if (unlikely(iocb->aio_reserved2)) {
pr_debug("EINVAL: reserve field set\n");
return -EINVAL;
}
/* prevent overflows */
if (unlikely(
- (iocb.aio_buf != (unsigned long)iocb.aio_buf) ||
- (iocb.aio_nbytes != (size_t)iocb.aio_nbytes) ||
- ((ssize_t)iocb.aio_nbytes < 0)
+ (iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
+ (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) ||
+ ((ssize_t)iocb->aio_nbytes < 0)
)) {
pr_debug("EINVAL: overflow check\n");
return -EINVAL;
}
- req = aio_get_req(ctx);
- if (unlikely(!req))
+ if (!get_reqs_available(ctx))
return -EAGAIN;
- if (iocb.aio_flags & IOCB_FLAG_RESFD) {
+ ret = -EAGAIN;
+ req = aio_get_req(ctx);
+ if (unlikely(!req))
+ goto out_put_reqs_available;
+
+ if (iocb->aio_flags & IOCB_FLAG_RESFD) {
/*
* If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
* instance of the file* now. The file descriptor must be
* an eventfd() fd, and will be signaled for each completed
* event using the eventfd_signal() function.
*/
- req->ki_eventfd = eventfd_ctx_fdget((int) iocb.aio_resfd);
+ req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd);
if (IS_ERR(req->ki_eventfd)) {
ret = PTR_ERR(req->ki_eventfd);
req->ki_eventfd = NULL;
@@ -1833,32 +1850,32 @@
}
req->ki_user_iocb = user_iocb;
- req->ki_user_data = iocb.aio_data;
+ req->ki_user_data = iocb->aio_data;
- switch (iocb.aio_lio_opcode) {
+ switch (iocb->aio_lio_opcode) {
case IOCB_CMD_PREAD:
- ret = aio_read(&req->rw, &iocb, false, compat);
+ ret = aio_read(&req->rw, iocb, false, compat);
break;
case IOCB_CMD_PWRITE:
- ret = aio_write(&req->rw, &iocb, false, compat);
+ ret = aio_write(&req->rw, iocb, false, compat);
break;
case IOCB_CMD_PREADV:
- ret = aio_read(&req->rw, &iocb, true, compat);
+ ret = aio_read(&req->rw, iocb, true, compat);
break;
case IOCB_CMD_PWRITEV:
- ret = aio_write(&req->rw, &iocb, true, compat);
+ ret = aio_write(&req->rw, iocb, true, compat);
break;
case IOCB_CMD_FSYNC:
- ret = aio_fsync(&req->fsync, &iocb, false);
+ ret = aio_fsync(&req->fsync, iocb, false);
break;
case IOCB_CMD_FDSYNC:
- ret = aio_fsync(&req->fsync, &iocb, true);
+ ret = aio_fsync(&req->fsync, iocb, true);
break;
case IOCB_CMD_POLL:
- ret = aio_poll(req, &iocb);
+ ret = aio_poll(req, iocb);
break;
default:
- pr_debug("invalid aio operation %d\n", iocb.aio_lio_opcode);
+ pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
ret = -EINVAL;
break;
}
@@ -1872,14 +1889,25 @@
goto out_put_req;
return 0;
out_put_req:
- put_reqs_available(ctx, 1);
- percpu_ref_put(&ctx->reqs);
if (req->ki_eventfd)
eventfd_ctx_put(req->ki_eventfd);
- kmem_cache_free(kiocb_cachep, req);
+ iocb_put(req);
+out_put_reqs_available:
+ put_reqs_available(ctx, 1);
return ret;
}
+static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
+ bool compat)
+{
+ struct iocb iocb;
+
+ if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb))))
+ return -EFAULT;
+
+ return __io_submit_one(ctx, &iocb, user_iocb, compat);
+}
+
/* sys_io_submit:
* Queue the nr iocbs pointed to by iocbpp for processing. Returns
* the number of iocbs queued. May return -EINVAL if the aio_context
@@ -1912,7 +1940,8 @@
if (nr > ctx->nr_events)
nr = ctx->nr_events;
- blk_start_plug(&plug);
+ if (nr > AIO_PLUG_THRESHOLD)
+ blk_start_plug(&plug);
for (i = 0; i < nr; i++) {
struct iocb __user *user_iocb;
@@ -1925,7 +1954,8 @@
if (ret)
break;
}
- blk_finish_plug(&plug);
+ if (nr > AIO_PLUG_THRESHOLD)
+ blk_finish_plug(&plug);
percpu_ref_put(&ctx->users);
return i ? i : ret;
@@ -1952,7 +1982,8 @@
if (nr > ctx->nr_events)
nr = ctx->nr_events;
- blk_start_plug(&plug);
+ if (nr > AIO_PLUG_THRESHOLD)
+ blk_start_plug(&plug);
for (i = 0; i < nr; i++) {
compat_uptr_t user_iocb;
@@ -1965,7 +1996,8 @@
if (ret)
break;
}
- blk_finish_plug(&plug);
+ if (nr > AIO_PLUG_THRESHOLD)
+ blk_finish_plug(&plug);
percpu_ref_put(&ctx->users);
return i ? i : ret;
