From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.18 26/27] afs: Fix cell proc list
Date: Mon, 22 Oct 2018 06:19:23 -0400 [thread overview]
Message-ID: <20181022101924.40531-26-sashal@kernel.org> (raw)
In-Reply-To: <20181022101924.40531-1-sashal@kernel.org>
From: David Howells <dhowells@redhat.com>
[ Upstream commit 6b3944e42e2e554aa5a4be681ecd70dccd459114 ]
Access to the list of cells by /proc/net/afs/cells has a couple of
problems:
(1) It should be checking against SEQ_START_TOKEN for the keying the
header line.
(2) It's only holding the RCU read lock, so it can't just walk over the
list without following the proper RCU methods.
Fix these by using an hlist instead of an ordinary list and using the
appropriate accessor functions to follow it with RCU.
Since the code that adds a cell to the list must also necessarily change,
sort the list on insertion whilst we're at it.
Fixes: 989782dcdc91 ("afs: Overhaul cell database management")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/afs/cell.c | 17 +++++++++++++++--
fs/afs/dynroot.c | 2 +-
fs/afs/internal.h | 4 ++--
fs/afs/main.c | 2 +-
fs/afs/proc.c | 7 +++----
5 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index f3d0bef16d78..6127f0fcd62c 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -514,6 +514,8 @@ static int afs_alloc_anon_key(struct afs_cell *cell)
*/
static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell)
{
+ struct hlist_node **p;
+ struct afs_cell *pcell;
int ret;
if (!cell->anonymous_key) {
@@ -534,7 +536,18 @@ static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell)
return ret;
mutex_lock(&net->proc_cells_lock);
- list_add_tail(&cell->proc_link, &net->proc_cells);
+ for (p = &net->proc_cells.first; *p; p = &(*p)->next) {
+ pcell = hlist_entry(*p, struct afs_cell, proc_link);
+ if (strcmp(cell->name, pcell->name) < 0)
+ break;
+ }
+
+ cell->proc_link.pprev = p;
+ cell->proc_link.next = *p;
+ rcu_assign_pointer(*p, &cell->proc_link.next);
+ if (cell->proc_link.next)
+ cell->proc_link.next->pprev = &cell->proc_link.next;
+
afs_dynroot_mkdir(net, cell);
mutex_unlock(&net->proc_cells_lock);
return 0;
@@ -550,7 +563,7 @@ static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell)
afs_proc_cell_remove(cell);
mutex_lock(&net->proc_cells_lock);
- list_del_init(&cell->proc_link);
+ hlist_del_rcu(&cell->proc_link);
afs_dynroot_rmdir(net, cell);
mutex_unlock(&net->proc_cells_lock);
diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 174e843f0633..7de7223843cc 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -286,7 +286,7 @@ int afs_dynroot_populate(struct super_block *sb)
return -ERESTARTSYS;
net->dynroot_sb = sb;
- list_for_each_entry(cell, &net->proc_cells, proc_link) {
+ hlist_for_each_entry(cell, &net->proc_cells, proc_link) {
ret = afs_dynroot_mkdir(net, cell);
if (ret < 0)
goto error;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 9778df135717..270d1caa27c6 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -241,7 +241,7 @@ struct afs_net {
seqlock_t cells_lock;
struct mutex proc_cells_lock;
- struct list_head proc_cells;
+ struct hlist_head proc_cells;
/* Known servers. Theoretically each fileserver can only be in one
* cell, but in practice, people create aliases and subsets and there's
@@ -319,7 +319,7 @@ struct afs_cell {
struct afs_net *net;
struct key *anonymous_key; /* anonymous user key for this cell */
struct work_struct manager; /* Manager for init/deinit/dns */
- struct list_head proc_link; /* /proc cell list link */
+ struct hlist_node proc_link; /* /proc cell list link */
#ifdef CONFIG_AFS_FSCACHE
struct fscache_cookie *cache; /* caching cookie */
#endif
diff --git a/fs/afs/main.c b/fs/afs/main.c
index e84fe822a960..107427688edd 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -87,7 +87,7 @@ static int __net_init afs_net_init(struct net *net_ns)
timer_setup(&net->cells_timer, afs_cells_timer, 0);
mutex_init(&net->proc_cells_lock);
- INIT_LIST_HEAD(&net->proc_cells);
+ INIT_HLIST_HEAD(&net->proc_cells);
seqlock_init(&net->fs_lock);
net->fs_servers = RB_ROOT;
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 476dcbb79713..9101f62707af 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -33,9 +33,8 @@ static inline struct afs_net *afs_seq2net_single(struct seq_file *m)
static int afs_proc_cells_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = list_entry(v, struct afs_cell, proc_link);
- struct afs_net *net = afs_seq2net(m);
- if (v == &net->proc_cells) {
+ if (v == SEQ_START_TOKEN) {
/* display header on line 1 */
seq_puts(m, "USE NAME\n");
return 0;
@@ -50,12 +49,12 @@ static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
__acquires(rcu)
{
rcu_read_lock();
- return seq_list_start_head(&afs_seq2net(m)->proc_cells, *_pos);
+ return seq_hlist_start_head_rcu(&afs_seq2net(m)->proc_cells, *_pos);
}
static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
{
- return seq_list_next(v, &afs_seq2net(m)->proc_cells, pos);
+ return seq_hlist_next_rcu(v, &afs_seq2net(m)->proc_cells, pos);
}
static void afs_proc_cells_stop(struct seq_file *m, void *v)
--
2.17.1
next prev parent reply other threads:[~2018-10-22 10:20 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-22 10:18 [PATCH AUTOSEL 4.18 01/27] ARM: dts: imx53-qsb: disable 1.2GHz OPP Sasha Levin
2018-10-22 10:18 ` [PATCH AUTOSEL 4.18 02/27] s390/hibernate: fix error handling when suspend cpu != resume cpu Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 03/27] perf report: Don't try to map ip to invalid map Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 04/27] Input: i8042 - enable keyboard wakeups by default when s2idle is used Sasha Levin
2018-10-22 16:58 ` Dmitry Torokhov
2018-10-23 15:48 ` Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 05/27] Input: mousedev - add a schedule point in mousedev_write() Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 06/27] perf python: Use -Wno-redundant-decls to build with PYTHON=python3 Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 07/27] perf record: Use unmapped IP for inline callchain cursors Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 08/27] Input: evdev - add a schedule point in evdev_write() Sasha Levin
2018-10-22 17:02 ` Dmitry Torokhov
2018-10-23 15:49 ` Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 09/27] Input: uinput - add a schedule point in uinput_inject_events() Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 10/27] rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 11/27] rxrpc: Carry call state out of locked section in rxrpc_rotate_tx_window() Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 12/27] rxrpc: Only take the rwind and mtu values from latest ACK Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 13/27] rxrpc: Fix connection-level abort handling Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 14/27] KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP_DD=m Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 15/27] net: ena: fix warning in rmmod caused by double iounmap Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 16/27] net: ena: fix rare bug when failed restart/resume is followed by driver removal Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 17/27] net: ena: fix NULL dereference due to untimely napi initialization Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 18/27] libertas: call into generic suspend code before turning off power Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 19/27] gpio: Assign gpio_irq_chip::parents to non-stack pointer Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 20/27] IB/mlx5: Unmap DMA addr from HCA before IOMMU Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 21/27] rds: RDS (tcp) hangs on sendto() to unresponding address Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 22/27] selftests: rtnetlink.sh explicitly requires bash Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 23/27] selftests: udpgso_bench.sh " Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 24/27] vmlinux.lds.h: Fix incomplete .text.exit discards Sasha Levin
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 25/27] vmlinux.lds.h: Fix linker warnings about orphan .LPBX sections Sasha Levin
2018-10-22 10:19 ` Sasha Levin [this message]
2018-10-22 10:19 ` [PATCH AUTOSEL 4.18 27/27] fs/fat/fatent.c: add cond_resched() to fat_count_free_clusters() Sasha Levin
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