Hi
Thanks for your patch. I've tested it and confirmed it solves the problem
we found.
It might be helpful to add the link of the original patch, as that could
better illustrate the issue.
(Link:
https://lore.kernel.org/all/20241213035908.1789132-1-lilingfeng3@xxxxxxxxxx/)
This is how I reproduce the problem and verify whether the problem is
solved.
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index df9669d4ded7..c19b1b66708c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2326,6 +2326,9 @@ static int nfs4_open_reclaim(struct
nfs4_state_owner *sp, struct nfs4_state *sta
clear_bit(NFS_DELEGATED_STATE, &state->flags);
nfs_state_clear_open_state_flags(state);
ret = nfs4_do_open_reclaim(ctx, state);
+ printk("first will sleep 20s\n");
+ msleep(20 * 1000);
+ printk("first sleep 20s ok\n");
put_nfs_open_context(ctx);
return ret;
}
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index e67420729ecd..679e1201734f 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4312,6 +4312,9 @@ nfsd4_encode_open_delegation4(struct xdr_stream
*xdr, struct nfsd4_open *open)
/* delegation_type */
if (xdr_stream_encode_u32(xdr, open->op_delegate_type) != XDR_UNIT)
return nfserr_resource;
+ printk("%s %d open->op_delegate_type %d\n", __func__, __LINE__,
open->op_delegate_type);
+ printk("%s %d force to write\n", __func__, __LINE__);
+ open->op_delegate_type = OPEN_DELEGATE_WRITE;
switch (open->op_delegate_type) {
case OPEN_DELEGATE_NONE:
status = nfs_ok;
[root@nfs_test2 test]# cat unlink_test.c
#include<stdio.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
int main()
{
int fd;
if(unlink("/mnt/sdbb/nfs_testfile1209")<0){
printf("unlink error !\n");
}
printf("unlink done\n");
return 0;
}
[root@nfs_test2 test]#
1) reproduce the problem -- state manager is blocked
[2025-02-05 15:26:35] Fedora 26 (Twenty Six)
[2025-02-05 15:26:35] Kernel 6.14.0-rc1-00028-g5c8c229261f1-dirty on an
x86_64 (ttyS0)
[2025-02-05 15:26:35]
[2025-02-05 15:26:35] nfs_test2 login: root
[2025-02-05 15:26:59] Password:
[2025-02-05 15:27:01] Last login: Wed Feb 5 14:55:23 on ttyS0
[2025-02-05 15:27:04] [root@nfs_test2 ~]# mkfs.ext4 -F /dev/sdb
[2025-02-05 15:27:30] mke2fs 1.46.5 (30-Dec-2021)
[2025-02-05 15:27:30] /dev/sdb contains a ext4 file system
[2025-02-05 15:27:30] last mounted on /mnt/sdb on Wed Feb 5
14:55:30 2025
[2025-02-05 15:27:30] Discarding device blocks: 0/5242880
done
[2025-02-05 15:27:30] Creating filesystem with 5242880 4k blocks and
1310720 inodes
[2025-02-05 15:27:30] Filesystem UUID: 4cf675ad-dc35-41e4-beb4-a8cd3c996d09
[2025-02-05 15:27:30] Superblock backups stored on blocks:
[2025-02-05 15:27:30] 32768, 98304, 163840, 229376, 294912, 819200,
884736, 1605632, 2654208,
[2025-02-05 15:27:30] 4096000
[2025-02-05 15:27:30]
[2025-02-05 15:27:30] Allocating group tables: 0/160 done
[2025-02-05 15:27:30] Writing inode tables: 0/160 done
[2025-02-05 15:27:30] Creating journal (32768 blocks): done
[2025-02-05 15:27:30] Writing superblocks and filesystem accounting
information: 0/160 done
[2025-02-05 15:27:30]
[2025-02-05 15:27:30] [root@nfs_test2 ~]# mount /dev/sdb /mnt/sdb
[2025-02-05 15:27:30] [root@nfs_test2 ~]# touch /mnt/sdb/nfs_testfile1209
[2025-02-05 15:27:30] [root@nfs_test2 ~]# echo "/mnt
*(rw,no_root_squash,fsid=0)" > /etc/exports
[2025-02-05 15:27:30] [root@nfs_test2 ~]# echo "/mnt/sdb
*(rw,no_root_squash,fsid=1)" >> /etc/exports
[2025-02-05 15:27:30] [root@nfs_test2 ~]# systemctl restart nfs-server
[2025-02-05 15:27:35] [root@nfs_test2 ~]# mount -t nfs -o rw,vers=4.1
127.0.0.1:/sdb /mnt/sdbb
[2025-02-05 15:27:38] [root@nfs_test2 ~]# exec 4<>
/mnt/sdbb/nfs_testfile1209
[2025-02-05 15:27:43] [ 130.524039][ T2885]
nfsd4_encode_open_delegation4 4315 open->op_delegate_type 0
[2025-02-05 15:27:43] [ 130.525002][ T2885]
nfsd4_encode_open_delegation4 4316 force to write
[2025-02-05 15:27:43] -bash: /mnt/sdbb/nfs_testfile1209: Remote I/O error
[2025-02-05 15:27:43] [root@nfs_test2 ~]#
[2025-02-05 15:28:46] [root@nfs_test2 ~]# exec 4<>
/mnt/sdbb/nfs_testfile1209
[2025-02-05 15:28:46] [ 193.806267][ T2885]
nfsd4_encode_open_delegation4 4315 open->op_delegate_type 2
[2025-02-05 15:28:46] [ 193.807239][ T2885]
nfsd4_encode_open_delegation4 4316 force to write
[2025-02-05 15:28:50]
[2025-02-05 15:28:52] [root@nfs_test2 ~]#
[2025-02-05 15:28:52] [root@nfs_test2 ~]# cd test/
[2025-02-05 15:29:02] [root@nfs_test2 test]# ./unlink_test
[2025-02-05 15:29:20] unlink done
[2025-02-05 15:29:20] [root@nfs_test2 test]# systemctl restart nfs-server
[2025-02-05 15:29:25] [root@nfs_test2 test]#
[2025-02-05 15:29:28] [root@nfs_test2 test]# [ 287.897206][ T2961]
nfsd4_encode_open_delegation4 4315 open->op_delegate_type 2
[2025-02-05 15:30:20] [ 287.898198][ T2961]
nfsd4_encode_open_delegation4 4316 force to write
[2025-02-05 15:30:20] [ 287.899477][ T2976] first will sleep 20s
[2025-02-05 15:30:22]
[2025-02-05 15:30:22] [root@nfs_test2 test]# exec 4<&-
[2025-02-05 15:30:23] [root@nfs_test2 test]# [ 308.308973][ T2976]
first sleep 20s ok
[2025-02-05 15:30:43]
[2025-02-05 15:30:43] [root@nfs_test2 test]# ps aux | grep D
[2025-02-05 15:30:52] USER PID %CPU %MEM VSZ RSS TTY
STAT START TIME COMMAND
[2025-02-05 15:30:52] root 489 0.0 0.0 97940 7352 ?
Ss 15:20 0:00 /usr/sbin/sshd -D
[2025-02-05 15:30:52] root 2966 0.1 0.0 270316 3384 ?
Ssl 15:23 0:00 /usr/sbin/gssproxy -D
[2025-02-05 15:30:52] root 2976 0.0 0.0 0 0 ?
D 15:24 0:00 [127.0.0.1-manag]
[2025-02-05 15:30:52] root 2981 0.0 0.0 119468 2356 ttyS0
S+ 15:24 0:00 grep --color=auto D
[2025-02-05 15:30:52] [root@nfs_test2 test]# cat /proc/2976/stack
[2025-02-05 15:30:58] [<0>] rpc_wait_bit_killable+0xd/0x90
[2025-02-05 15:30:58] [<0>] _nfs4_proc_delegreturn+0x4f6/0x6b0
[2025-02-05 15:30:58] [<0>] nfs4_proc_delegreturn+0x136/0x280
[2025-02-05 15:30:58] [<0>] nfs_do_return_delegation+0xaa/0x100
[2025-02-05 15:30:58] [<0>] nfs_end_delegation_return+0x11e/0x1e0
[2025-02-05 15:30:58] [<0>] nfs_complete_unlink+0xb4/0x150
[2025-02-05 15:30:58] [<0>] nfs_dentry_iput+0x37/0xa0
[2025-02-05 15:30:58] [<0>] __dentry_kill+0xc3/0x280
[2025-02-05 15:30:58] [<0>] dput.part.0+0x26c/0x4e0
[2025-02-05 15:30:58] [<0>] __put_nfs_open_context+0x1c8/0x250
[2025-02-05 15:30:58] [<0>] nfs4_open_reclaim+0x73/0xc0
[2025-02-05 15:30:58] [<0>] __nfs4_reclaim_open_state+0x32/0x150
[2025-02-05 15:30:58] [<0>] nfs4_reclaim_open_state+0x154/0x3a0
[2025-02-05 15:30:58] [<0>] nfs4_do_reclaim+0x217/0x4a0
[2025-02-05 15:30:58] [<0>] nfs4_state_manager+0x5ff/0xa80
[2025-02-05 15:30:58] [<0>] nfs4_run_state_manager+0x164/0x320
[2025-02-05 15:30:58] [<0>] kthread+0x20a/0x3d0
[2025-02-05 15:30:58] [<0>] ret_from_fork+0x2f/0x50
[2025-02-05 15:30:58] [<0>] ret_from_fork_asm+0x1a/0x30
[2025-02-05 15:30:58] [root@nfs_test2 test]#
2) verify whether the problem has been solved -- state manager is not
blocked
[2025-02-05 15:52:15] Fedora 26 (Twenty Six)
[2025-02-05 15:52:15] Kernel 6.14.0-rc1-00028-g5c8c229261f1-dirty on an
x86_64 (ttyS0)
[2025-02-05 15:52:15]
[2025-02-05 15:52:15] nfs_test2 login: root
[2025-02-05 15:52:48] Password:
[2025-02-05 15:52:50] Last login: Wed Feb 5 15:21:14 from 192.168.240.1
[2025-02-05 15:52:53] [root@nfs_test2 ~]# mkfs.ext4 -F /dev/sdb
[2025-02-05 15:55:16] mke2fs 1.46.5 (30-Dec-2021)
[2025-02-05 15:55:16] /dev/sdb contains a ext4 file system
[2025-02-05 15:55:16] last mounted on /mnt/sdb on Wed Feb 5
15:21:36 2025
[2025-02-05 15:55:16] Discarding device blocks: 0/5242880
done
[2025-02-05 15:55:16] Creating filesystem with 5242880 4k blocks and
1310720 inodes
[2025-02-05 15:55:16] Filesystem UUID: 018cc6a0-605e-4741-881b-947f381f5e6a
[2025-02-05 15:55:16] Superblock backups stored on blocks:
[2025-02-05 15:55:16] 32768, 98304, 163840, 229376, 294912, 819200,
884736, 1605632, 2654208,
[2025-02-05 15:55:16] 4096000
[2025-02-05 15:55:16]
[2025-02-05 15:55:16] Allocating group tables: 0/160 done
[2025-02-05 15:55:16] Writing inode tables: 0/160 done
[2025-02-05 15:55:16] Creating journal (32768 blocks): done
[2025-02-05 15:55:16] Writing superblocks and filesystem accounting
information: 0/160 done
[2025-02-05 15:55:16]
[2025-02-05 15:55:16] [root@nfs_test2 ~]# mount /dev/sdb /mnt/sdb
[2025-02-05 15:55:17] [root@nfs_test2 ~]# touch /mnt/sdb/nfs_testfile1209
[2025-02-05 15:55:17] [root@nfs_test2 ~]# echo "/mnt
*(rw,no_root_squash,fsid=0)" > /etc/exports
[2025-02-05 15:55:17] [root@nfs_test2 ~]# echo "/mnt/sdb
*(rw,no_root_squash,fsid=1)" >> /etc/exports
[2025-02-05 15:55:17] [root@nfs_test2 ~]# systemctl restart nfs-server
[2025-02-05 15:55:20] [root@nfs_test2 ~]# mount -t nfs -o rw,vers=4.1
127.0.0.1:/sdb /mnt/sdbb
[2025-02-05 15:56:40] [root@nfs_test2 ~]# cat /mnt/sdbb/nfs_testfile1209
[2025-02-05 15:56:46] ls /mnt/sdbbexec 4<> /mnt/sdbb/nfs_testfile1209
[2025-02-05 15:56:48] [ 335.367080][ T2772]
nfsd4_encode_open_delegation4 4315 open->op_delegate_type 2
[2025-02-05 15:56:48] [ 335.368033][ T2772]
nfsd4_encode_open_delegation4 4316 force to write
[2025-02-05 15:56:48] [root@nfs_test2 ~]# cd test/
[2025-02-05 15:57:14] [root@nfs_test2 test]# ./unlink_test
[2025-02-05 15:57:15] unlink done
[2025-02-05 15:57:15] [root@nfs_test2 test]# systemctl restart nfs-server
[2025-02-05 15:57:23] [root@nfs_test2 test]#
[2025-02-05 15:57:25] [root@nfs_test2 test]# [ 423.194508][ T2856]
nfsd4_encode_open_delegation4 4315 open->op_delegate_type 2
[2025-02-05 15:58:15] [ 423.195470][ T2856]
nfsd4_encode_open_delegation4 4316 force to write
[2025-02-05 15:58:15] [ 423.196712][ T2872] first will sleep 20s
[2025-02-05 15:58:17]
[2025-02-05 15:58:17] [root@nfs_test2 test]# exec 4<&-
[2025-02-05 15:58:18] [root@nfs_test2 test]# [ 443.570528][ T2872]
first sleep 20s ok
[2025-02-05 15:58:39]
[2025-02-05 15:58:39] [root@nfs_test2 test]# ps aux | grep D
[2025-02-05 15:58:43] USER PID %CPU %MEM VSZ RSS TTY
STAT START TIME COMMAND
[2025-02-05 15:58:43] root 483 0.0 0.0 97940 7336 ?
Ss 15:46 0:00 /usr/sbin/sshd -D
[2025-02-05 15:58:43] root 2861 0.1 0.0 270316 3492 ?
Ssl 15:51 0:00 /usr/sbin/gssproxy -D
[2025-02-05 15:58:43] root 2879 0.0 0.0 119468 2356 ttyS0
S+ 15:52 0:00 grep --color=auto D
[2025-02-05 15:58:43] [root@nfs_test2 test]#
在 2025/2/2 4:00, trondmy@xxxxxxxxxx 写道:
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
If the file is sillyrenamed, and slated for delete on close, it is
possible for a server reboot to triggeer an open reclaim, with can again
race with the application call to close(). When that happens, the call
to put_nfs_open_context() can trigger a synchronous delegreturn call
which deadlocks because it is not marked as privileged.
Instead, ensure that the call to nfs4_inode_return_delegation_on_close()
catches the delegreturn, and schedules it asynchronously.
Reported-by: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
Fixes: adb4b42d19ae ("Return the delegation when deleting sillyrenamed files")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/delegation.c | 37 +++++++++++++++++++++++++++++++++++++
fs/nfs/delegation.h | 1 +
fs/nfs/nfs4proc.c | 3 +++
3 files changed, 41 insertions(+)
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 035ba52742a5..4db912f56230 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -780,6 +780,43 @@ int nfs4_inode_return_delegation(struct inode *inode)
return 0;
}
+/**
+ * nfs4_inode_set_return_delegation_on_close - asynchronously return a delegation
+ * @inode: inode to process
+ *
+ * This routine is called to request that the delegation be returned as soon
+ * as the file is closed. If the file is already closed, the delegation is
+ * immediately returned.
+ */
+void nfs4_inode_set_return_delegation_on_close(struct inode *inode)
+{
+ struct nfs_delegation *delegation;
+ struct nfs_delegation *ret = NULL;
+
+ if (!inode)
+ return;
+ rcu_read_lock();
+ delegation = nfs4_get_valid_delegation(inode);
+ if (!delegation)
+ goto out;
+ spin_lock(&delegation->lock);
+ if (!delegation->inode)
+ goto out_unlock;
+ if (list_empty(&NFS_I(inode)->open_files) &&
+ !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
+ /* Refcount matched in nfs_end_delegation_return() */
+ ret = nfs_get_delegation(delegation);
+ } else
+ set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
+out_unlock:
+ spin_unlock(&delegation->lock);
+ if (ret)
+ nfs_clear_verifier_delegated(inode);
+out:
+ rcu_read_unlock();
+ nfs_end_delegation_return(inode, ret, 0);
+}
+
/**
* nfs4_inode_return_delegation_on_close - asynchronously return a delegation
* @inode: inode to process
diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
index 71524d34ed20..8ff5ab9c5c25 100644
--- a/fs/nfs/delegation.h
+++ b/fs/nfs/delegation.h
@@ -49,6 +49,7 @@ void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
unsigned long pagemod_limit, u32 deleg_type);
int nfs4_inode_return_delegation(struct inode *inode);
void nfs4_inode_return_delegation_on_close(struct inode *inode);
+void nfs4_inode_set_return_delegation_on_close(struct inode *inode);
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);
void nfs_inode_evict_delegation(struct inode *inode);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index df9669d4ded7..c25ecdb76d30 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3906,8 +3906,11 @@ nfs4_atomic_open(struct inode *dir, struct nfs_open_context *ctx,
static void nfs4_close_context(struct nfs_open_context *ctx, int is_sync)
{
+ struct dentry *dentry = ctx->dentry;
if (ctx->state == NULL)
return;
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ nfs4_inode_set_return_delegation_on_close(d_inode(dentry));
if (is_sync)
nfs4_close_sync(ctx->state, _nfs4_ctx_to_openmode(ctx));
else
