Junxiao Bi
2022-Jun-03 22:28 UTC
[Ocfs2-devel] [PATCH] Revert "ocfs2: mount shared volume without ha stack"
This reverts commit 912f655d78c5d4ad05eac287f23a435924df7144.
This commit introduced a regression that can cause mount hung.
The changes in __ocfs2_find_empty_slot causes that any node with
none-zero node number can grab the slot that was already taken by
node 0, so node 1 will access the same journal with node 0, when it
try to grab journal cluster lock, it will hung because it was already
acquired by node 0.
It's very easy to reproduce this, in one cluster, mount node 0 first,
then node 1, you will see the following call trace from node 1.
[13148.735424] INFO: task mount.ocfs2:53045 blocked for more than 122 seconds.
[13148.739691] Not tainted 5.15.0-2148.0.4.el8uek.mountracev2.x86_64 #2
[13148.742560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[13148.745846] task:mount.ocfs2 state:D stack: 0 pid:53045 ppid: 53044
flags:0x00004000
[13148.749354] Call Trace:
[13148.750718] <TASK>
[13148.752019] ? usleep_range+0x90/0x89
[13148.753882] __schedule+0x210/0x567
[13148.755684] schedule+0x44/0xa8
[13148.757270] schedule_timeout+0x106/0x13c
[13148.759273] ? __prepare_to_swait+0x53/0x78
[13148.761218] __wait_for_common+0xae/0x163
[13148.763144] __ocfs2_cluster_lock.constprop.0+0x1d6/0x870 [ocfs2]
[13148.765780] ? ocfs2_inode_lock_full_nested+0x18d/0x398 [ocfs2]
[13148.768312] ocfs2_inode_lock_full_nested+0x18d/0x398 [ocfs2]
[13148.770968] ocfs2_journal_init+0x91/0x340 [ocfs2]
[13148.773202] ocfs2_check_volume+0x39/0x461 [ocfs2]
[13148.775401] ? iput+0x69/0xba
[13148.777047] ocfs2_mount_volume.isra.0.cold+0x40/0x1f5 [ocfs2]
[13148.779646] ocfs2_fill_super+0x54b/0x853 [ocfs2]
[13148.781756] mount_bdev+0x190/0x1b7
[13148.783443] ? ocfs2_remount+0x440/0x440 [ocfs2]
[13148.785634] legacy_get_tree+0x27/0x48
[13148.787466] vfs_get_tree+0x25/0xd0
[13148.789270] do_new_mount+0x18c/0x2d9
[13148.791046] __x64_sys_mount+0x10e/0x142
[13148.792911] do_syscall_64+0x3b/0x89
[13148.794667] entry_SYSCALL_64_after_hwframe+0x170/0x0
[13148.797051] RIP: 0033:0x7f2309f6e26e
[13148.798784] RSP: 002b:00007ffdcee7d408 EFLAGS: 00000246 ORIG_RAX:
00000000000000a5
[13148.801974] RAX: ffffffffffffffda RBX: 00007ffdcee7d4a0 RCX: 00007f2309f6e26e
[13148.804815] RDX: 0000559aa762a8ae RSI: 0000559aa939d340 RDI: 0000559aa93a22b0
[13148.807719] RBP: 00007ffdcee7d5b0 R08: 0000559aa93a2290 R09: 00007f230a0b4820
[13148.810659] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdcee7d420
[13148.813609] R13: 0000000000000000 R14: 0000559aa939f000 R15: 0000000000000000
[13148.816564] </TASK>
To fix it, we can just fix __ocfs2_find_empty_slot. But original commit
introduced the feature to mount ocfs2 locally even it is cluster based,
that is a very dangerous, it can easily cause serious data corruption,
there is no way to stop other nodes mounting the fs and corrupting it.
Setup ha or other cluster-aware stack is just the cost that we have to
take for avoiding corruption, otherwise we have to do it in kernel.
Fixes: 912f655d78c5("ocfs2: mount shared volume without ha stack")
Cc: <stable at vger.kernel.org>
Signed-off-by: Junxiao Bi <junxiao.bi at oracle.com>
---
fs/ocfs2/ocfs2.h | 4 +---
fs/ocfs2/slot_map.c | 46 +++++++++++++++++++--------------------------
fs/ocfs2/super.c | 21 ---------------------
3 files changed, 20 insertions(+), 51 deletions(-)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 337527571461..740b64238312 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -277,7 +277,6 @@ enum ocfs2_mount_options
OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT = 1 << 15, /* Journal Async Commit */
OCFS2_MOUNT_ERRORS_CONT = 1 << 16, /* Return EIO to the calling process
on error */
OCFS2_MOUNT_ERRORS_ROFS = 1 << 17, /* Change filesystem to read-only on
error */
- OCFS2_MOUNT_NOCLUSTER = 1 << 18, /* No cluster aware filesystem mount */
};
#define OCFS2_OSB_SOFT_RO 0x0001
@@ -673,8 +672,7 @@ static inline int ocfs2_cluster_o2cb_global_heartbeat(struct
ocfs2_super *osb)
static inline int ocfs2_mount_local(struct ocfs2_super *osb)
{
- return ((osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT)
- || (osb->s_mount_opt & OCFS2_MOUNT_NOCLUSTER));
+ return (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT);
}
static inline int ocfs2_uses_extended_slot_map(struct ocfs2_super *osb)
diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index 0b0ae3ebb0cf..da7718cef735 100644
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -252,16 +252,14 @@ static int __ocfs2_find_empty_slot(struct ocfs2_slot_info
*si,
int i, ret = -ENOSPC;
if ((preferred >= 0) && (preferred < si->si_num_slots)) {
- if (!si->si_slots[preferred].sl_valid ||
- !si->si_slots[preferred].sl_node_num) {
+ if (!si->si_slots[preferred].sl_valid) {
ret = preferred;
goto out;
}
}
for(i = 0; i < si->si_num_slots; i++) {
- if (!si->si_slots[i].sl_valid ||
- !si->si_slots[i].sl_node_num) {
+ if (!si->si_slots[i].sl_valid) {
ret = i;
break;
}
@@ -456,30 +454,24 @@ int ocfs2_find_slot(struct ocfs2_super *osb)
spin_lock(&osb->osb_lock);
ocfs2_update_slot_info(si);
- if (ocfs2_mount_local(osb))
- /* use slot 0 directly in local mode */
- slot = 0;
- else {
- /* search for ourselves first and take the slot if it already
- * exists. Perhaps we need to mark this in a variable for our
- * own journal recovery? Possibly not, though we certainly
- * need to warn to the user */
- slot = __ocfs2_node_num_to_slot(si, osb->node_num);
+ /* search for ourselves first and take the slot if it already
+ * exists. Perhaps we need to mark this in a variable for our
+ * own journal recovery? Possibly not, though we certainly
+ * need to warn to the user */
+ slot = __ocfs2_node_num_to_slot(si, osb->node_num);
+ if (slot < 0) {
+ /* if no slot yet, then just take 1st available
+ * one. */
+ slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
if (slot < 0) {
- /* if no slot yet, then just take 1st available
- * one. */
- slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
- if (slot < 0) {
- spin_unlock(&osb->osb_lock);
- mlog(ML_ERROR, "no free slots available!\n");
- status = -EINVAL;
- goto bail;
- }
- } else
- printk(KERN_INFO "ocfs2: Slot %d on device (%s) was "
- "already allocated to this node!\n",
- slot, osb->dev_str);
- }
+ spin_unlock(&osb->osb_lock);
+ mlog(ML_ERROR, "no free slots available!\n");
+ status = -EINVAL;
+ goto bail;
+ }
+ } else
+ printk(KERN_INFO "ocfs2: Slot %d on device (%s) was already "
+ "allocated to this node!\n", slot, osb->dev_str);
ocfs2_set_slot(si, slot, osb->node_num);
osb->slot_num = slot;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index f7298816d8d9..438be028935d 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -172,7 +172,6 @@ enum {
Opt_dir_resv_level,
Opt_journal_async_commit,
Opt_err_cont,
- Opt_nocluster,
Opt_err,
};
@@ -206,7 +205,6 @@ static const match_table_t tokens = {
{Opt_dir_resv_level, "dir_resv_level=%u"},
{Opt_journal_async_commit, "journal_async_commit"},
{Opt_err_cont, "errors=continue"},
- {Opt_nocluster, "nocluster"},
{Opt_err, NULL}
};
@@ -618,13 +616,6 @@ static int ocfs2_remount(struct super_block *sb, int
*flags, char *data)
goto out;
}
- tmp = OCFS2_MOUNT_NOCLUSTER;
- if ((osb->s_mount_opt & tmp) != (parsed_options.mount_opt & tmp)) {
- ret = -EINVAL;
- mlog(ML_ERROR, "Cannot change nocluster option on remount\n");
- goto out;
- }
-
tmp = OCFS2_MOUNT_HB_LOCAL | OCFS2_MOUNT_HB_GLOBAL |
OCFS2_MOUNT_HB_NONE;
if ((osb->s_mount_opt & tmp) != (parsed_options.mount_opt & tmp)) {
@@ -865,7 +856,6 @@ static int ocfs2_verify_userspace_stack(struct ocfs2_super
*osb,
}
if (ocfs2_userspace_stack(osb) &&
- !(osb->s_mount_opt & OCFS2_MOUNT_NOCLUSTER) &&
strncmp(osb->osb_cluster_stack, mopt->cluster_stack,
OCFS2_STACK_LABEL_LEN)) {
mlog(ML_ERROR,
@@ -1137,11 +1127,6 @@ static int ocfs2_fill_super(struct super_block *sb, void
*data, int silent)
osb->s_mount_opt & OCFS2_MOUNT_DATA_WRITEBACK ?
"writeback" :
"ordered");
- if ((osb->s_mount_opt & OCFS2_MOUNT_NOCLUSTER) &&
- !(osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT))
- printk(KERN_NOTICE "ocfs2: The shared device (%s) is mounted "
- "without cluster aware mode.\n", osb->dev_str);
-
atomic_set(&osb->vol_state, VOLUME_MOUNTED);
wake_up(&osb->osb_mount_event);
@@ -1452,9 +1437,6 @@ static int ocfs2_parse_options(struct super_block *sb,
case Opt_journal_async_commit:
mopt->mount_opt |= OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT;
break;
- case Opt_nocluster:
- mopt->mount_opt |= OCFS2_MOUNT_NOCLUSTER;
- break;
default:
mlog(ML_ERROR,
"Unrecognized mount option \"%s\" "
@@ -1566,9 +1548,6 @@ static int ocfs2_show_options(struct seq_file *s, struct
dentry *root)
if (opts & OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT)
seq_printf(s, ",journal_async_commit");
- if (opts & OCFS2_MOUNT_NOCLUSTER)
- seq_printf(s, ",nocluster");
-
return 0;
}
--
2.24.3 (Apple Git-128)
heming.zhao at suse.com
2022-Jun-04 08:45 UTC
[Ocfs2-devel] [PATCH] Revert "ocfs2: mount shared volume without ha stack"
Hello Junxiao, On 6/4/22 06:28, Junxiao Bi via Ocfs2-devel wrote:> This reverts commit 912f655d78c5d4ad05eac287f23a435924df7144. > > This commit introduced a regression that can cause mount hung. > The changes in __ocfs2_find_empty_slot causes that any node with > none-zero node number can grab the slot that was already taken by > node 0, so node 1 will access the same journal with node 0, when it > try to grab journal cluster lock, it will hung because it was already > acquired by node 0. > It's very easy to reproduce this, in one cluster, mount node 0 first, > then node 1, you will see the following call trace from node 1.From your description, it looks your env mixed local-mount & clustered-mount. Could you mind to share your test/reproducible steps. And which ha stack do you use, pmck or o2cb? I failed to reproduce it, my test steps (with pcmk stack): ``` node1: mount -t ocfs2 /dev/vdd /mnt node2: for i in {1..100}; do echo "mount <$i>"; mount -t ocfs2 /dev/vdd /mnt; sleep 3; echo "umount"; umount /mnt; done ``` This local mount feature helps SUSE customers to maintain ocfs2 partition, it's useful. I want to find whether there is a idear way to fix the hung issue.> > [13148.735424] INFO: task mount.ocfs2:53045 blocked for more than 122 seconds. > [13148.739691] Not tainted 5.15.0-2148.0.4.el8uek.mountracev2.x86_64 #2 > [13148.742560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [13148.745846] task:mount.ocfs2 state:D stack: 0 pid:53045 ppid: 53044 flags:0x00004000 > [13148.749354] Call Trace: > [13148.750718] <TASK> > [13148.752019] ? usleep_range+0x90/0x89 > [13148.753882] __schedule+0x210/0x567 > [13148.755684] schedule+0x44/0xa8 > [13148.757270] schedule_timeout+0x106/0x13c > [13148.759273] ? __prepare_to_swait+0x53/0x78 > [13148.761218] __wait_for_common+0xae/0x163 > [13148.763144] __ocfs2_cluster_lock.constprop.0+0x1d6/0x870 [ocfs2] > [13148.765780] ? ocfs2_inode_lock_full_nested+0x18d/0x398 [ocfs2] > [13148.768312] ocfs2_inode_lock_full_nested+0x18d/0x398 [ocfs2] > [13148.770968] ocfs2_journal_init+0x91/0x340 [ocfs2] > [13148.773202] ocfs2_check_volume+0x39/0x461 [ocfs2] > [13148.775401] ? iput+0x69/0xba > [13148.777047] ocfs2_mount_volume.isra.0.cold+0x40/0x1f5 [ocfs2] > [13148.779646] ocfs2_fill_super+0x54b/0x853 [ocfs2] > [13148.781756] mount_bdev+0x190/0x1b7 > [13148.783443] ? ocfs2_remount+0x440/0x440 [ocfs2] > [13148.785634] legacy_get_tree+0x27/0x48 > [13148.787466] vfs_get_tree+0x25/0xd0 > [13148.789270] do_new_mount+0x18c/0x2d9 > [13148.791046] __x64_sys_mount+0x10e/0x142 > [13148.792911] do_syscall_64+0x3b/0x89 > [13148.794667] entry_SYSCALL_64_after_hwframe+0x170/0x0 > [13148.797051] RIP: 0033:0x7f2309f6e26e > [13148.798784] RSP: 002b:00007ffdcee7d408 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 > [13148.801974] RAX: ffffffffffffffda RBX: 00007ffdcee7d4a0 RCX: 00007f2309f6e26e > [13148.804815] RDX: 0000559aa762a8ae RSI: 0000559aa939d340 RDI: 0000559aa93a22b0 > [13148.807719] RBP: 00007ffdcee7d5b0 R08: 0000559aa93a2290 R09: 00007f230a0b4820 > [13148.810659] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdcee7d420 > [13148.813609] R13: 0000000000000000 R14: 0000559aa939f000 R15: 0000000000000000 > [13148.816564] </TASK> > > To fix it, we can just fix __ocfs2_find_empty_slot. But original commit > introduced the feature to mount ocfs2 locally even it is cluster based, > that is a very dangerous, it can easily cause serious data corruption, > there is no way to stop other nodes mounting the fs and corrupting it.I can't follow your meaning. When users want to use local mount feature, they MUST know what they are doing, and how to use it. From mount.ocfs2 (8), there also writes *only* mount fs on *one* node at the same time. And also tell user fs will be damaged under wrong action. ``` nocluster This option allows users to mount a clustered volume without configuring the cluster stack. However, you must be aware that you can only mount the file system from one node at the same time, otherwise, the file system may be damaged. Please use it with caution. ```> Setup ha or other cluster-aware stack is just the cost that we have to > take for avoiding corruption, otherwise we have to do it in kernel.It's a little bit serious to totally revert this commit just under lacking sanity check. If you or maintainer think the local mount should do more jobs to prevent mix local-mount and clustered-mount scenario, we could add more sanity check during local mounting. Thanks, Heming