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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Xiubo Li <xiubli@redhat.com>, Jeff Layton <jlayton@kernel.org>,
	Ilya Dryomov <idryomov@gmail.com>,
	Sasha Levin <sashal@kernel.org>,
	ceph-devel@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 19/50] ceph: do not execute direct write in parallel if O_APPEND is specified
Date: Sat, 22 Feb 2020 21:22:04 -0500	[thread overview]
Message-ID: <20200223022235.1404-19-sashal@kernel.org> (raw)
In-Reply-To: <20200223022235.1404-1-sashal@kernel.org>

From: Xiubo Li <xiubli@redhat.com>

[ Upstream commit 8e4473bb50a1796c9c32b244e5dbc5ee24ead937 ]

In O_APPEND & O_DIRECT mode, the data from different writers will
be possibly overlapping each other since they take the shared lock.

For example, both Writer1 and Writer2 are in O_APPEND and O_DIRECT
mode:

          Writer1                         Writer2

     shared_lock()                   shared_lock()
     getattr(CAP_SIZE)               getattr(CAP_SIZE)
     iocb->ki_pos = EOF              iocb->ki_pos = EOF
     write(data1)
                                     write(data2)
     shared_unlock()                 shared_unlock()

The data2 will overlap the data1 from the same file offset, the
old EOF.

Switch to exclusive lock instead when O_APPEND is specified.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ceph/file.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 11929d2bb594c..cd09e63d682b7 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1418,6 +1418,7 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	struct ceph_cap_flush *prealloc_cf;
 	ssize_t count, written = 0;
 	int err, want, got;
+	bool direct_lock = false;
 	loff_t pos;
 	loff_t limit = max(i_size_read(inode), fsc->max_file_size);
 
@@ -1428,8 +1429,11 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (!prealloc_cf)
 		return -ENOMEM;
 
+	if ((iocb->ki_flags & (IOCB_DIRECT | IOCB_APPEND)) == IOCB_DIRECT)
+		direct_lock = true;
+
 retry_snap:
-	if (iocb->ki_flags & IOCB_DIRECT)
+	if (direct_lock)
 		ceph_start_io_direct(inode);
 	else
 		ceph_start_io_write(inode);
@@ -1519,14 +1523,15 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 		/* we might need to revert back to that point */
 		data = *from;
-		if (iocb->ki_flags & IOCB_DIRECT) {
+		if (iocb->ki_flags & IOCB_DIRECT)
 			written = ceph_direct_read_write(iocb, &data, snapc,
 							 &prealloc_cf);
-			ceph_end_io_direct(inode);
-		} else {
+		else
 			written = ceph_sync_write(iocb, &data, pos, snapc);
+		if (direct_lock)
+			ceph_end_io_direct(inode);
+		else
 			ceph_end_io_write(inode);
-		}
 		if (written > 0)
 			iov_iter_advance(from, written);
 		ceph_put_snap_context(snapc);
@@ -1577,7 +1582,7 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	goto out_unlocked;
 out:
-	if (iocb->ki_flags & IOCB_DIRECT)
+	if (direct_lock)
 		ceph_end_io_direct(inode);
 	else
 		ceph_end_io_write(inode);
-- 
2.20.1


  parent reply	other threads:[~2020-02-23  2:23 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-23  2:21 [PATCH AUTOSEL 5.4 01/50] ipmi:ssif: Handle a possible NULL pointer reference Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 02/50] drm/msm: Set dma maximum segment size for mdss Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 03/50] sched/core: Don't skip remote tick for idle CPUs Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 04/50] timers/nohz: Update NOHZ load in remote tick Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 05/50] sched/fair: Prevent unlimited runtime on throttled group Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 06/50] dax: pass NOWAIT flag to iomap_apply Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 07/50] mac80211: consider more elements in parsing CRC Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 08/50] cfg80211: check wiphy driver existence for drvinfo report Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 09/50] s390/zcrypt: fix card and queue total counter wrap Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 10/50] qmi_wwan: re-add DW5821e pre-production variant Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 11/50] qmi_wwan: unconditionally reject 2 ep interfaces Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 12/50] NFSv4: Fix races between open and dentry revalidation Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 13/50] perf/smmuv3: Use platform_get_irq_optional() for wired interrupt Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 14/50] arm/ftrace: Fix BE text poking Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 15/50] sched/psi: Fix OOB write when writing 0 bytes to PSI files Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 16/50] perf/x86/intel: Add Elkhart Lake support Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 17/50] perf/x86/cstate: Add Tremont support Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 18/50] perf/x86/msr: " Sasha Levin
2020-02-23  2:22 ` Sasha Levin [this message]
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 20/50] ARM: dts: sti: fixup sound frame-inversion for stihxxx-b2120.dtsi Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 21/50] drm/amd/display: Do not set optimized_require to false after plane disable Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 22/50] RDMA/siw: Remove unwanted WARN_ON in siw_cm_llp_data_ready() Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 23/50] drm/amd/display: Check engine is not NULL before acquiring Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 24/50] drm/amd/display: Limit minimum DPPCLK to 100MHz Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 25/50] drm/amd/display: Add initialitions for PLL2 clock source Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 26/50] amdgpu: Prevent build errors regarding soft/hard-float FP ABI tags Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 27/50] soc/tegra: fuse: Fix build with Tegra194 configuration Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 28/50] i40e: Fix the conditional for i40e_vc_validate_vqs_bitmaps Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 29/50] net: ena: fix potential crash when rxfh key is NULL Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 30/50] net: ena: fix uses of round_jiffies() Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 31/50] net: ena: add missing ethtool TX timestamping indication Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 32/50] net: ena: fix incorrect default RSS key Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 33/50] net: ena: rss: do not allocate key when not supported Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 34/50] net: ena: rss: fix failure to get indirection table Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 35/50] net: ena: rss: store hash function as values and not bits Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 36/50] net: ena: fix incorrectly saving queue numbers when setting RSS indirection table Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 37/50] net: ena: fix corruption of dev_idx_to_host_tbl Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 38/50] net: ena: ethtool: use correct value for crc32 hash Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 39/50] net: ena: ena-com.c: prevent NULL pointer dereference Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 40/50] enic: prevent waking up stopped tx queues over watchdog reset Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 41/50] ice: update Unit Load Status bitmask to check after reset Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 42/50] cifs: Fix mode output in debugging statements Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 43/50] bcache: ignore pending signals when creating gc and allocator thread Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 44/50] cfg80211: add missing policy for NL80211_ATTR_STATUS_CODE Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 45/50] mac80211: fix wrong 160/80+80 MHz setting Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 46/50] net: hns3: add management table after IMP reset Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 47/50] net: hns3: fix a copying IPv6 address error in hclge_fd_get_flow_tuples() Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 48/50] nvme/tcp: fix bug on double requeue when send fails Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 49/50] nvme: prevent warning triggered by nvme_stop_keep_alive Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 50/50] nvme/pci: move cqe check after device shutdown Sasha Levin

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