The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Possible dependencies:
2ec33a6c3cca ("io_uring/rw: ensure kiocb_end_write() is always called") b000145e9907 ("io_uring/rw: defer fsnotify calls to task context") 4d9cb92ca41d ("io_uring/rw: fix short rw error handling") f2ccb5aed7bc ("io_uring: make io_kiocb_to_cmd() typesafe") 14b146b688ad ("io_uring: notification completion optimisation") 6a9ce66f4d08 ("io_uring/net: make page accounting more consistent") 2e32ba5607ee ("io_uring/net: checks errors of zc mem accounting") 3ff1a0d395c0 ("io_uring: enable managed frags with register buffers") 492dddb4f6e3 ("io_uring: add zc notification flush requests") 4379d5f15b3f ("io_uring: rename IORING_OP_FILES_UPDATE") 63809137ebb5 ("io_uring: flush notifiers after sendzc") 10c7d33ecd51 ("io_uring: sendzc with fixed buffers") e29e3bd4b968 ("io_uring: account locked pages for non-fixed zc") 06a5464be84e ("io_uring: wire send zc request type") bc24d6bd32df ("io_uring: add notification slot registration") 68ef5578efc8 ("io_uring: add rsrc referencing for notifiers") e58d498e81ba ("io_uring: complete notifiers in tw") eb4a299b2f95 ("io_uring: cache struct io_notif") eb42cebb2cf2 ("io_uring: add zc notification infrastructure") e70cb60893ca ("io_uring: export io_put_task()")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 2ec33a6c3cca9fe2465e82050c81f5ffdc508b36 Mon Sep 17 00:00:00 2001 From: Jens Axboe axboe@kernel.dk Date: Tue, 11 Oct 2022 09:06:23 -0600 Subject: [PATCH] io_uring/rw: ensure kiocb_end_write() is always called
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 david@fromorbit.com Link: https://lore.kernel.org/all/20221010050319.GC2703033@dread.disaster.area/ Signed-off-by: Jens Axboe axboe@kernel.dk
diff --git a/io_uring/rw.c b/io_uring/rw.c index 453e0ae92160..100de2626e47 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -234,11 +234,34 @@ static void kiocb_end_write(struct io_kiocb *req) } }
+/* + * 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 = io_kiocb_to_cmd(req, struct io_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 (unlikely(res != req->cqe.res)) { 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 | REQ_F_PARTIAL_IO; return true; } @@ -264,15 +287,7 @@ static inline int io_fixup_rw_res(struct io_kiocb *req, long res)
static void io_req_rw_complete(struct io_kiocb *req, bool *locked) { - struct io_rw *rw = io_kiocb_to_cmd(req, struct io_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); }
@@ -317,6 +332,11 @@ static int kiocb_done(struct io_kiocb *req, ssize_t ret, req->file->f_pos = rw->kiocb.ki_pos; if (ret >= 0 && (rw->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_set_res(req, final_ret, io_put_kbuf(req, issue_flags)); return IOU_OK;