From b10acfcd61b25ad5b97c155aad9c45d5ecbb9f39 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sun, 22 Jan 2023 10:36:37 -0700 Subject: [PATCH] io_uring/rw: ensure kiocb_end_write() is always called commit 2ec33a6c3cca9fe2465e82050c81f5ffdc508b36 upstream. A previous commit moved the notifications and end-write handling, but it is now missing a few spots where we also want to call both of those. Without that, we can potentially be missing file notifications, and more importantly, have an imbalance in the super_block writers sem accounting. Fixes: b000145e9907 ("io_uring/rw: defer fsnotify calls to task context") Reported-by: Dave Chinner Link: https://lore.kernel.org/all/20221010050319.GC2703033@dread.disaster.area/ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 57 +++++++++++++++++++++++++++++---------------- 1 file changed, 37 insertions(+), 20 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index e851c6855895..d9d9f6599a89 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2703,11 +2703,34 @@ static bool io_rw_should_reissue(struct io_kiocb *req) } #endif +/* + * Trigger the notifications after having done some IO, and finish the write + * accounting, if any. + */ +static void io_req_io_end(struct io_kiocb *req) +{ + struct io_rw *rw = &req->rw; + + WARN_ON(!in_task()); + + if (rw->kiocb.ki_flags & IOCB_WRITE) { + kiocb_end_write(req); + fsnotify_modify(req->file); + } else { + fsnotify_access(req->file); + } +} + static bool __io_complete_rw_common(struct io_kiocb *req, long res) { if (res != req->result) { if ((res == -EAGAIN || res == -EOPNOTSUPP) && io_rw_should_reissue(req)) { + /* + * Reissue will start accounting again, finish the + * current cycle. + */ + io_req_io_end(req); req->flags |= REQ_F_REISSUE; return true; } @@ -2749,25 +2772,9 @@ static void io_req_task_complete(struct io_kiocb *req, bool *locked) } } -static void __io_complete_rw(struct io_kiocb *req, long res, long res2, - unsigned int issue_flags) -{ - if (__io_complete_rw_common(req, res)) - return; - __io_req_complete(req, issue_flags, io_fixup_rw_res(req, res), io_put_rw_kbuf(req)); -} - static void io_req_rw_complete(struct io_kiocb *req, bool *locked) { - struct io_rw *rw = &req->rw; - - if (rw->kiocb.ki_flags & IOCB_WRITE) { - kiocb_end_write(req); - fsnotify_modify(req->file); - } else { - fsnotify_access(req->file); - } - + io_req_io_end(req); io_req_task_complete(req, locked); } @@ -3035,10 +3042,20 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret, if (req->flags & REQ_F_CUR_POS) req->file->f_pos = kiocb->ki_pos; - if (ret >= 0 && (kiocb->ki_complete == io_complete_rw)) - __io_complete_rw(req, ret, 0, issue_flags); - else + if (ret >= 0 && (kiocb->ki_complete == io_complete_rw)) { + if (!__io_complete_rw_common(req, ret)) { + /* + * Safe to call io_end from here as we're inline + * from the submission path. + */ + io_req_io_end(req); + __io_req_complete(req, issue_flags, + io_fixup_rw_res(req, ret), + io_put_rw_kbuf(req)); + } + } else { io_rw_done(kiocb, ret); + } if (req->flags & REQ_F_REISSUE) { req->flags &= ~REQ_F_REISSUE;