From: Jens Axboe <axboe@kernel.dk>
To: linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org
Cc: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk,
Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 3/3] io_uring: use AT_STATX_CACHED for IORING_OP_STATX fast path
Date: Mon, 25 Jan 2021 14:36:14 -0700 [thread overview]
Message-ID: <20210125213614.24001-4-axboe@kernel.dk> (raw)
In-Reply-To: <20210125213614.24001-1-axboe@kernel.dk>
Instead of always going async, we can now attempt a cached attempt by
using AT_STATX_CACHED. This turns into LOOKUP_CACHED, and ensures that
we'll only do a fast path dentry lookup for path resolution.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index c246df2f95a4..99799cc5a42e 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4394,20 +4394,27 @@ static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
static int io_statx(struct io_kiocb *req, bool force_nonblock)
{
struct io_statx *ctx = &req->statx;
+ bool cached_set;
int ret;
- if (force_nonblock) {
- /* only need file table for an actual valid fd */
- if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
- req->flags |= REQ_F_NO_FILE_TABLE;
- return -EAGAIN;
- }
+ cached_set = ctx->flags & AT_STATX_CACHED;
+ if (force_nonblock)
+ ctx->flags |= AT_STATX_CACHED;
ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
ctx->buffer);
- if (ret < 0)
+ if (ret < 0) {
+ /* only retry if nonblock wasn't set */
+ if (ret == -EAGAIN && (!cached_set && force_nonblock)) {
+ /* only need file table for an actual valid fd */
+ if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
+ req->flags |= REQ_F_NO_FILE_TABLE;
+ ctx->flags &= ~AT_STATX_CACHED;
+ return -EAGAIN;
+ }
req_set_fail_links(req);
+ }
io_req_complete(req, ret);
return 0;
}
--
2.30.0
next prev parent reply other threads:[~2021-01-25 21:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 21:36 [PATCHSET RFC] support RESOLVE_CACHED for statx Jens Axboe
2021-01-25 21:36 ` [PATCH 1/3] fs: add support for AT_STATX_CACHED Jens Axboe
2021-01-25 21:36 ` [PATCH 2/3] fs: ensure that ->getattr() honors AT_STATX_CACHED Jens Axboe
2021-01-25 21:36 ` Jens Axboe [this message]
2021-01-25 23:39 ` [PATCHSET RFC] support RESOLVE_CACHED for statx Linus Torvalds
2021-01-26 1:06 ` Jens Axboe
2021-01-26 1:28 ` Linus Torvalds
2021-01-26 1:31 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210125213614.24001-4-axboe@kernel.dk \
--to=axboe@kernel.dk \
--cc=io-uring@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.