From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>, Qian Cai <cai@redhat.com>,
Sasha Levin <sashal@kernel.org>,
linux-fsdevel@vger.kernel.org
Subject: [PATCH AUTOSEL 5.8 15/29] fuse: fix the ->direct_IO() treatment of iov_iter
Date: Mon, 28 Sep 2020 21:30:12 -0400 [thread overview]
Message-ID: <20200929013027.2406344-15-sashal@kernel.org> (raw)
In-Reply-To: <20200929013027.2406344-1-sashal@kernel.org>
From: Al Viro <viro@zeniv.linux.org.uk>
[ Upstream commit 933a3752babcf6513117d5773d2b70782d6ad149 ]
the callers rely upon having any iov_iter_truncate() done inside
->direct_IO() countered by iov_iter_reexpand().
Reported-by: Qian Cai <cai@redhat.com>
Tested-by: Qian Cai <cai@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/fuse/file.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 83d917f7e5425..98e170cc0b932 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3091,11 +3091,10 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
ssize_t ret = 0;
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
- bool async_dio = ff->fc->async_dio;
loff_t pos = 0;
struct inode *inode;
loff_t i_size;
- size_t count = iov_iter_count(iter);
+ size_t count = iov_iter_count(iter), shortened = 0;
loff_t offset = iocb->ki_pos;
struct fuse_io_priv *io;
@@ -3103,17 +3102,9 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
inode = file->f_mapping->host;
i_size = i_size_read(inode);
- if ((iov_iter_rw(iter) == READ) && (offset > i_size))
+ if ((iov_iter_rw(iter) == READ) && (offset >= i_size))
return 0;
- /* optimization for short read */
- if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) {
- if (offset >= i_size)
- return 0;
- iov_iter_truncate(iter, fuse_round_up(ff->fc, i_size - offset));
- count = iov_iter_count(iter);
- }
-
io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
if (!io)
return -ENOMEM;
@@ -3129,15 +3120,22 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
* By default, we want to optimize all I/Os with async request
* submission to the client filesystem if supported.
*/
- io->async = async_dio;
+ io->async = ff->fc->async_dio;
io->iocb = iocb;
io->blocking = is_sync_kiocb(iocb);
+ /* optimization for short read */
+ if (io->async && !io->write && offset + count > i_size) {
+ iov_iter_truncate(iter, fuse_round_up(ff->fc, i_size - offset));
+ shortened = count - iov_iter_count(iter);
+ count -= shortened;
+ }
+
/*
* We cannot asynchronously extend the size of a file.
* In such case the aio will behave exactly like sync io.
*/
- if ((offset + count > i_size) && iov_iter_rw(iter) == WRITE)
+ if ((offset + count > i_size) && io->write)
io->blocking = true;
if (io->async && io->blocking) {
@@ -3155,6 +3153,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
} else {
ret = __fuse_direct_read(io, iter, &pos);
}
+ iov_iter_reexpand(iter, iov_iter_count(iter) + shortened);
if (io->async) {
bool blocking = io->blocking;
--
2.25.1
next prev parent reply other threads:[~2020-09-29 1:36 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-29 1:29 [PATCH AUTOSEL 5.8 01/29] clocksource/drivers/timer-gx6605s: Fixup counter reload Sasha Levin
2020-09-29 1:29 ` [PATCH AUTOSEL 5.8 02/29] vboxsf: Fix the check for the old binary mount-arguments struct Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 03/29] mt76: mt7915: use ieee80211_free_txskb to free tx skbs Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 04/29] libbpf: Remove arch-specific include path in Makefile Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 05/29] drivers/net/wan/hdlc_fr: Add needed_headroom for PVC devices Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 06/29] Revert "wlcore: Adding suppoprt for IGTK key in wlcore driver" Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 07/29] drm/sun4i: mixer: Extend regmap max_register Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 08/29] net: dsa: microchip: look for phy-mode in port nodes Sasha Levin
2020-09-29 5:56 ` Helmut Grohne
2020-10-04 12:46 ` Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 09/29] hv_netvsc: Cache the current data path to avoid duplicate call and message Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 10/29] net: dec: de2104x: Increase receive ring size for Tulip Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 11/29] rndis_host: increase sleep time in the query-response loop Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 12/29] nvme-pci: disable the write zeros command for Intel 600P/P3100 Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 13/29] nvme-core: get/put ctrl and transport module in nvme_dev_open/release() Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 14/29] regmap: debugfs: Fix handling of name string for debugfs init delays Sasha Levin
2020-09-29 8:33 ` Charles Keepax
2020-10-04 12:54 ` Sasha Levin
2020-09-29 1:30 ` Sasha Levin [this message]
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 16/29] drivers/net/wan/lapbether: Make skb->protocol consistent with the header Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 17/29] drivers/net/wan/hdlc: Set skb->protocol before transmitting Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 18/29] mac80211: Fix radiotap header channel flag for 6GHz band Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 19/29] mac80211: do not allow bigger VHT MPDUs than the hardware supports Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 20/29] tracing: Make the space reserved for the pid wider Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 21/29] tools/io_uring: fix compile breakage Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 22/29] io_uring: mark statx/files_update/epoll_ctl as non-SQPOLL Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 23/29] cpuidle: psci: Fix suspicious RCU usage Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 24/29] spi: fsl-espi: Only process interrupts for expected events Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 25/29] net: dsa: felix: fix some key offsets for IP4_TCP_UDP VCAP IS2 entries Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 26/29] nvme-pci: fix NULL req in completion handler Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 27/29] nvme-fc: fail new connections to a deleted host or remote port Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 28/29] spi: fsl-dspi: fix use-after-free in remove path Sasha Levin
2020-09-29 6:22 ` Sascha Hauer
2020-10-04 12:58 ` Sasha Levin
2020-09-29 1:30 ` [PATCH AUTOSEL 5.8 29/29] scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.* Sasha Levin
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