aio: use iovec array rather than the single one
Previously, we only offer a single iovec to handle all the read/write cases, so
the PREADV/PWRITEV request always need to alloc more iovec buffer when copying
user vectors.
If we use a tmp iovec array rather than the single one, some small PREADV/PWRITEV
workloads(vector size small than the tmp buffer) will not need to alloc more
iovec buffer when copying user vectors.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
diff --git a/fs/aio.c b/fs/aio.c
index d6d9520..0fd9181 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1243,12 +1243,12 @@
if (compat)
ret = compat_rw_copy_check_uvector(rw,
(struct compat_iovec __user *)buf,
- *nr_segs, 1, *iovec, iovec);
+ *nr_segs, UIO_FASTIOV, *iovec, iovec);
else
#endif
ret = rw_copy_check_uvector(rw,
(struct iovec __user *)buf,
- *nr_segs, 1, *iovec, iovec);
+ *nr_segs, UIO_FASTIOV, *iovec, iovec);
if (ret < 0)
return ret;
@@ -1285,7 +1285,7 @@
fmode_t mode;
aio_rw_op *rw_op;
rw_iter_op *iter_op;
- struct iovec inline_vec, *iovec = &inline_vec;
+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
struct iov_iter iter;
switch (opcode) {
@@ -1320,7 +1320,7 @@
if (!ret)
ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes);
if (ret < 0) {
- if (iovec != &inline_vec)
+ if (iovec != inline_vecs)
kfree(iovec);
return ret;
}
@@ -1367,7 +1367,7 @@
return -EINVAL;
}
- if (iovec != &inline_vec)
+ if (iovec != inline_vecs)
kfree(iovec);
if (ret != -EIOCBQUEUED) {