From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>,
linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org
Subject: [PATCH AUTOSEL 5.9 16/33] io_uring: handle -EOPNOTSUPP on path resolution
Date: Wed, 25 Nov 2020 10:35:33 -0500 [thread overview]
Message-ID: <20201125153550.810101-16-sashal@kernel.org> (raw)
In-Reply-To: <20201125153550.810101-1-sashal@kernel.org>
From: Jens Axboe <axboe@kernel.dk>
[ Upstream commit 944d1444d53f5a213457e5096db370cfd06923d4 ]
Any attempt to do path resolution on /proc/self from an async worker will
yield -EOPNOTSUPP. We can safely do that resolution from the task itself,
and without blocking, so retry it from there.
Ideally io_uring would know this upfront and not have to go through the
worker thread to find out, but that doesn't currently seem feasible.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/io_uring.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e74a56f6915c0..46a68a8439895 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -435,6 +435,7 @@ struct io_sr_msg {
struct io_open {
struct file *file;
int dfd;
+ bool ignore_nonblock;
struct filename *filename;
struct open_how how;
unsigned long nofile;
@@ -3590,6 +3591,7 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
return ret;
}
req->open.nofile = rlimit(RLIMIT_NOFILE);
+ req->open.ignore_nonblock = false;
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
@@ -3637,7 +3639,7 @@ static int io_openat2(struct io_kiocb *req, bool force_nonblock)
struct file *file;
int ret;
- if (force_nonblock)
+ if (force_nonblock && !req->open.ignore_nonblock)
return -EAGAIN;
ret = build_open_flags(&req->open.how, &op);
@@ -3652,6 +3654,21 @@ static int io_openat2(struct io_kiocb *req, bool force_nonblock)
if (IS_ERR(file)) {
put_unused_fd(ret);
ret = PTR_ERR(file);
+ /*
+ * A work-around to ensure that /proc/self works that way
+ * that it should - if we get -EOPNOTSUPP back, then assume
+ * that proc_self_get_link() failed us because we're in async
+ * context. We should be safe to retry this from the task
+ * itself with force_nonblock == false set, as it should not
+ * block on lookup. Would be nice to know this upfront and
+ * avoid the async dance, but doesn't seem feasible.
+ */
+ if (ret == -EOPNOTSUPP && io_wq_current_is_worker()) {
+ req->open.ignore_nonblock = true;
+ refcount_inc(&req->refs);
+ io_req_task_queue(req);
+ return 0;
+ }
} else {
fsnotify_open(file);
fd_install(ret, file);
--
2.27.0
next prev parent reply other threads:[~2020-11-25 15:42 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-25 15:35 [PATCH AUTOSEL 5.9 01/33] HID: uclogic: Add ID for Trust Flex Design Tablet Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 02/33] HID: ite: Replace ABS_MISC 120/121 events with touchpad on/off keypresses Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 03/33] HID: cypress: Support Varmilo Keyboards' media hotkeys Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 04/33] HID: add support for Sega Saturn Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 05/33] Input: i8042 - allow insmod to succeed on devices without an i8042 controller Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 06/33] HID: hid-sensor-hub: Fix issue with devices with no report ID Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 07/33] staging: ralink-gdma: fix kconfig dependency bug for DMA_RALINK Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 08/33] HID: add HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE for Gamevice devices Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 09/33] dmaengine: xilinx_dma: use readl_poll_timeout_atomic variant Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 10/33] x86/xen: don't unbind uninitialized lock_kicker_irq Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 11/33] kunit: fix display of failed expectations for strings Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 12/33] HID: logitech-hidpp: Add HIDPP_CONSUMER_VENDOR_KEYS quirk for the Dinovo Edge Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 13/33] HID: Add Logitech Dinovo Edge battery quirk Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 14/33] proc: don't allow async path resolution of /proc/self components Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 15/33] nvme: free sq/cq dbbuf pointers when dbbuf set fails Sasha Levin
2020-11-25 15:35 ` Sasha Levin [this message]
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 17/33] net: stmmac: dwmac_lib: enlarge dma reset timeout Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 18/33] vdpasim: fix "mac_pton" undefined error Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 19/33] vhost: add helper to check if a vq has been setup Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 20/33] vhost scsi: alloc cmds per vq instead of session Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 21/33] vhost scsi: fix cmd completion race Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 22/33] vhost scsi: add lun parser helper Sasha Levin
2020-11-25 17:48 ` Paolo Bonzini
2020-11-25 18:01 ` Sasha Levin
2020-11-25 18:08 ` Paolo Bonzini
2020-11-29 4:13 ` Sasha Levin
2020-11-29 17:34 ` Paolo Bonzini
2020-11-29 21:06 ` Sasha Levin
2020-11-30 8:33 ` Paolo Bonzini
2020-11-30 13:28 ` Greg KH
2020-11-30 13:52 ` Paolo Bonzini
2020-11-30 13:57 ` Greg KH
2020-11-30 14:00 ` Paolo Bonzini
2020-11-30 17:34 ` Sasha Levin
2020-11-30 17:38 ` Sasha Levin
2020-11-30 17:52 ` Paolo Bonzini
2020-11-30 19:44 ` Mike Christie
2020-11-30 20:29 ` Paolo Bonzini
2020-11-30 23:59 ` Sasha Levin
2020-12-04 8:27 ` Paolo Bonzini
2020-12-04 15:49 ` Sasha Levin
2020-12-04 16:12 ` Joe Perches
2020-12-04 17:08 ` Paolo Bonzini
2020-12-05 20:59 ` Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 23/33] vhost scsi: Add support for LUN resets Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 24/33] cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 25/33] dmaengine: pl330: _prep_dma_memcpy: Fix wrong burst size Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 26/33] scsi: libiscsi: Fix NOP race condition Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 27/33] scsi: target: iscsi: Fix cmd abort fabric stop race Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 28/33] lockdep: Put graph lock/unlock under lock_recursion protection Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 29/33] perf/x86: fix sysfs type mismatches Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 30/33] xtensa: uaccess: Add missing __user to strncpy_from_user() prototype Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 31/33] x86/dumpstack: Do not try to access user space code of other tasks Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 32/33] net: dsa: mv88e6xxx: Wait for EEPROM done after HW reset Sasha Levin
2020-11-25 15:35 ` [PATCH AUTOSEL 5.9 33/33] xfs: don't allow NOWAIT DIO across extent boundaries Sasha Levin
2020-11-25 21:52 ` Dave Chinner
2020-11-25 23:46 ` Sasha Levin
2020-11-26 7:13 ` Dave Chinner
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