From: Dai Ngo <dai.ngo@oracle.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: linux-nfs@vger.kernel.org
Subject: Re: [PATCH v4 1/1] NFSv4.2: Fix NFS4ERR_STALE error when doing inter server copy
Date: Tue, 20 Oct 2020 11:34:35 -0700 [thread overview]
Message-ID: <fb514565-cd47-9180-2adc-f3ba4459202b@oracle.com> (raw)
In-Reply-To: <20201020170114.GF1133@fieldses.org>
On 10/20/20 10:01 AM, J. Bruce Fields wrote:
> On Sun, Oct 18, 2020 at 11:42:49PM -0400, Dai Ngo wrote:
>> NFS_FS=y as dependency of CONFIG_NFSD_V4_2_INTER_SSC still have
>> build errors and some configs with NFSD=m to get NFS4ERR_STALE
>> error when doing inter server copy.
>>
>> Added ops table in nfs_common for knfsd to access NFS client modules.
> OK, looks reasonable to me, applying. Does this resolve all the
> problems you've seen, or is there any bad case left?
Thanks Bruce.
With this patch, I no longer see the NFS4ERR_STALE in any config.
The problem with NFS4ERR_STALE was because of a bug in nfs42_ssc_open.
When CONFIG_NFSD_V4_2_INTER_SSC is not defined, nfs42_ssc_open
returns NULL which is incorrect allowing the operation to continue
until nfsd4_putfh which does not have the code to handle nfserr_stale.
With this patch, when CONFIG_NFSD_V4_2_INTER_SSC is not defined the
new nfs42_ssc_open returns ERR_PTR(-EIO) which causes the NFS client
to switch over to the split copying (read src and write to dst).
The other problem that I see was the "use-after-free" which I think
happens only on the 1st inter server copy. I will look into this:
Sep 23 01:08:10 nfsvmf24 kernel: ------------[ cut here ]------------
Sep 23 01:08:10 nfsvmf24 kernel: refcount_t: underflow; use-after-free.
Sep 23 01:08:10 nfsvmf24 kernel: WARNING: CPU: 0 PID: 4217 at lib/refcount.c:28 refcount_warn_saturate+0xae/0xf0
Sep 23 01:08:10 nfsvmf24 kernel: Modules linked in: cts rpcsec_gss_krb5 xt_REDIRECT xt_nat ip6table_nat ip6_tables iptable_nat nf_nat nf_conntrack btrfs nf_defrag_ipv6 nf_defrag_ipv4 blake2b_generic xor zstd_compress rfkill raid6_pq sb_edac intel_powerclamp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper sg pcspkr i2c_piix4 video ip_tables xfs libcrc32c sd_mod t10_pi ahci libahci libata e1000 crc32c_intel serio_raw dm_mirror dm_region_hash dm_log dm_mod
Sep 23 01:08:10 nfsvmf24 kernel: CPU: 0 PID: 4217 Comm: copy thread Not tainted 5.9.0-rc5+ #14
Sep 23 01:08:10 nfsvmf24 kernel: Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
Sep 23 01:08:10 nfsvmf24 kernel: RIP: 0010:refcount_warn_saturate+0xae/0xf0
Sep 23 01:08:10 nfsvmf24 kernel: Code: 99 83 31 01 01 e8 27 ba b6 ff 0f 0b 5d c3 80 3d 86 83 31 01 00 75 91 48 c7 c7 20 d3 3a 84 c6 05 76 83 31 01 01 e8 07 ba b6 ff <0f> 0b 5d c3 80 3d 64 83 31 01 00 0f 85 6d ff ff ff 48 c7 c7 78 d3
Sep 23 01:08:10 nfsvmf24 kernel: RSP: 0000:ffffc20300403e68 EFLAGS: 00010286
Sep 23 01:08:10 nfsvmf24 kernel: RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000027
Sep 23 01:08:10 nfsvmf24 kernel: RDX: 0000000000000027 RSI: 0000000000000086 RDI: ffff9e8c97c18c48
Sep 23 01:08:10 nfsvmf24 kernel: RBP: ffffc20300403e68 R08: ffff9e8c97c18c40 R09: 0000000000000004
Sep 23 01:08:10 nfsvmf24 kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff9e8c96693300
Sep 23 01:08:10 nfsvmf24 kernel: R13: ffff9e8c96693300 R14: ffff9e8c8a6e3000 R15: ffff9e8c959c5520
Sep 23 01:08:10 nfsvmf24 kernel: FS: 0000000000000000(0000) GS:ffff9e8c97c00000(0000) knlGS:0000000000000000
Sep 23 01:08:10 nfsvmf24 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 23 01:08:10 nfsvmf24 kernel: CR2: 000055aedfd031a8 CR3: 000000020ee6e000 CR4: 00000000000406f0
Sep 23 01:08:10 nfsvmf24 kernel: Call Trace:
Sep 23 01:08:10 nfsvmf24 kernel: nfsd_file_put_noref+0x8f/0xa0
Sep 23 01:08:10 nfsvmf24 kernel: nfsd_file_put+0x3e/0x90
Sep 23 01:08:10 nfsvmf24 kernel: nfsd4_do_copy+0xe5/0x150
Sep 23 01:08:10 nfsvmf24 kernel: nfsd4_do_async_copy+0x84/0x200
Sep 23 01:08:10 nfsvmf24 kernel: kthread+0x114/0x150
Sep 23 01:08:10 nfsvmf24 kernel: ? nfsd4_copy+0x4e0/0x4e0
Sep 23 01:08:10 nfsvmf24 kernel: ? kthread_park+0x90/0x90
Sep 23 01:08:10 nfsvmf24 kernel: ret_from_fork+0x22/0x30
-Dai
>
> --b.
>
>> Fixes: 3ac3711adb88 ("NFSD: Fix NFS server build errors")
>> Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
>> ---
>> changes from v2: fix 0-day build issues.
>> changes from v3: reacted to Bruce's comments, removed paranoid error checking.
>> ---
>> fs/nfs/nfs4file.c | 38 ++++++++++++++++----
>> fs/nfs/nfs4super.c | 5 +++
>> fs/nfs/super.c | 17 +++++++++
>> fs/nfs_common/Makefile | 1 +
>> fs/nfs_common/nfs_ssc.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/nfsd/Kconfig | 2 +-
>> fs/nfsd/nfs4proc.c | 3 +-
>> include/linux/nfs_ssc.h | 67 +++++++++++++++++++++++++++++++++++
>> 8 files changed, 219 insertions(+), 8 deletions(-)
>> create mode 100644 fs/nfs_common/nfs_ssc.c
>> create mode 100644 include/linux/nfs_ssc.h
>>
>> diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
>> index fdfc77486ace..984938024011 100644
>> --- a/fs/nfs/nfs4file.c
>> +++ b/fs/nfs/nfs4file.c
>> @@ -9,6 +9,7 @@
>> #include <linux/falloc.h>
>> #include <linux/mount.h>
>> #include <linux/nfs_fs.h>
>> +#include <linux/nfs_ssc.h>
>> #include "delegation.h"
>> #include "internal.h"
>> #include "iostat.h"
>> @@ -314,9 +315,8 @@ static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
>> static int read_name_gen = 1;
>> #define SSC_READ_NAME_BODY "ssc_read_%d"
>>
>> -struct file *
>> -nfs42_ssc_open(struct vfsmount *ss_mnt, struct nfs_fh *src_fh,
>> - nfs4_stateid *stateid)
>> +static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
>> + struct nfs_fh *src_fh, nfs4_stateid *stateid)
>> {
>> struct nfs_fattr fattr;
>> struct file *filep, *res;
>> @@ -398,14 +398,40 @@ struct file *
>> fput(filep);
>> goto out_free_name;
>> }
>> -EXPORT_SYMBOL_GPL(nfs42_ssc_open);
>> -void nfs42_ssc_close(struct file *filep)
>> +
>> +static void __nfs42_ssc_close(struct file *filep)
>> {
>> struct nfs_open_context *ctx = nfs_file_open_context(filep);
>>
>> ctx->state->flags = 0;
>> }
>> -EXPORT_SYMBOL_GPL(nfs42_ssc_close);
>> +
>> +static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
>> + .sco_open = __nfs42_ssc_open,
>> + .sco_close = __nfs42_ssc_close,
>> +};
>> +
>> +/**
>> + * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
>> + *
>> + * Return values:
>> + * None
>> + */
>> +void nfs42_ssc_register_ops(void)
>> +{
>> + nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
>> +}
>> +
>> +/**
>> + * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
>> + *
>> + * Return values:
>> + * None.
>> + */
>> +void nfs42_ssc_unregister_ops(void)
>> +{
>> + nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
>> +}
>> #endif /* CONFIG_NFS_V4_2 */
>>
>> const struct file_operations nfs4_file_operations = {
>> diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
>> index 0c1ab846b83d..93f5c1678ec2 100644
>> --- a/fs/nfs/nfs4super.c
>> +++ b/fs/nfs/nfs4super.c
>> @@ -7,6 +7,7 @@
>> #include <linux/mount.h>
>> #include <linux/nfs4_mount.h>
>> #include <linux/nfs_fs.h>
>> +#include <linux/nfs_ssc.h>
>> #include "delegation.h"
>> #include "internal.h"
>> #include "nfs4_fs.h"
>> @@ -279,6 +280,9 @@ static int __init init_nfs_v4(void)
>> if (err)
>> goto out2;
>>
>> +#ifdef CONFIG_NFS_V4_2
>> + nfs42_ssc_register_ops();
>> +#endif
>> register_nfs_version(&nfs_v4);
>> return 0;
>> out2:
>> @@ -297,6 +301,7 @@ static void __exit exit_nfs_v4(void)
>> unregister_nfs_version(&nfs_v4);
>> #ifdef CONFIG_NFS_V4_2
>> nfs4_xattr_cache_exit();
>> + nfs42_ssc_unregister_ops();
>> #endif
>> nfs4_unregister_sysctl();
>> nfs_idmap_quit();
>> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>> index 7a70287f21a2..f7dad8227a5f 100644
>> --- a/fs/nfs/super.c
>> +++ b/fs/nfs/super.c
>> @@ -57,6 +57,7 @@
>> #include <linux/rcupdate.h>
>>
>> #include <linux/uaccess.h>
>> +#include <linux/nfs_ssc.h>
>>
>> #include "nfs4_fs.h"
>> #include "callback.h"
>> @@ -85,6 +86,10 @@
>> };
>> EXPORT_SYMBOL_GPL(nfs_sops);
>>
>> +static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
>> + .sco_sb_deactive = nfs_sb_deactive,
>> +};
>> +
>> #if IS_ENABLED(CONFIG_NFS_V4)
>> static int __init register_nfs4_fs(void)
>> {
>> @@ -106,6 +111,16 @@ static void unregister_nfs4_fs(void)
>> }
>> #endif
>>
>> +static void nfs_ssc_register_ops(void)
>> +{
>> + nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
>> +}
>> +
>> +static void nfs_ssc_unregister_ops(void)
>> +{
>> + nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
>> +}
>> +
>> static struct shrinker acl_shrinker = {
>> .count_objects = nfs_access_cache_count,
>> .scan_objects = nfs_access_cache_scan,
>> @@ -133,6 +148,7 @@ int __init register_nfs_fs(void)
>> ret = register_shrinker(&acl_shrinker);
>> if (ret < 0)
>> goto error_3;
>> + nfs_ssc_register_ops();
>> return 0;
>> error_3:
>> nfs_unregister_sysctl();
>> @@ -152,6 +168,7 @@ void __exit unregister_nfs_fs(void)
>> unregister_shrinker(&acl_shrinker);
>> nfs_unregister_sysctl();
>> unregister_nfs4_fs();
>> + nfs_ssc_unregister_ops();
>> unregister_filesystem(&nfs_fs_type);
>> }
>>
>> diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile
>> index 4bebe834c009..fa82f5aaa6d9 100644
>> --- a/fs/nfs_common/Makefile
>> +++ b/fs/nfs_common/Makefile
>> @@ -7,3 +7,4 @@ obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o
>> nfs_acl-objs := nfsacl.o
>>
>> obj-$(CONFIG_GRACE_PERIOD) += grace.o
>> +obj-$(CONFIG_GRACE_PERIOD) += nfs_ssc.o
>> diff --git a/fs/nfs_common/nfs_ssc.c b/fs/nfs_common/nfs_ssc.c
>> new file mode 100644
>> index 000000000000..f43bbb373913
>> --- /dev/null
>> +++ b/fs/nfs_common/nfs_ssc.c
>> @@ -0,0 +1,94 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * fs/nfs_common/nfs_ssc_comm.c
>> + *
>> + * Helper for knfsd's SSC to access ops in NFS client modules
>> + *
>> + * Author: Dai Ngo <dai.ngo@oracle.com>
>> + *
>> + * Copyright (c) 2020, Oracle and/or its affiliates.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/fs.h>
>> +#include <linux/nfs_ssc.h>
>> +#include "../nfs/nfs4_fs.h"
>> +
>> +MODULE_LICENSE("GPL");
>> +
>> +struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl;
>> +EXPORT_SYMBOL_GPL(nfs_ssc_client_tbl);
>> +
>> +#ifdef CONFIG_NFS_V4_2
>> +/**
>> + * nfs42_ssc_register - install the NFS_V4 client ops in the nfs_ssc_client_tbl
>> + * @ops: NFS_V4 ops to be installed
>> + *
>> + * Return values:
>> + * None
>> + */
>> +void nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops)
>> +{
>> + nfs_ssc_client_tbl.ssc_nfs4_ops = ops;
>> +}
>> +EXPORT_SYMBOL_GPL(nfs42_ssc_register);
>> +
>> +/**
>> + * nfs42_ssc_unregister - uninstall the NFS_V4 client ops from
>> + * the nfs_ssc_client_tbl
>> + * @ops: ops to be uninstalled
>> + *
>> + * Return values:
>> + * None
>> + */
>> +void nfs42_ssc_unregister(const struct nfs4_ssc_client_ops *ops)
>> +{
>> + if (nfs_ssc_client_tbl.ssc_nfs4_ops != ops)
>> + return;
>> +
>> + nfs_ssc_client_tbl.ssc_nfs4_ops = NULL;
>> +}
>> +EXPORT_SYMBOL_GPL(nfs42_ssc_unregister);
>> +#endif /* CONFIG_NFS_V4_2 */
>> +
>> +#ifdef CONFIG_NFS_V4_2
>> +/**
>> + * nfs_ssc_register - install the NFS_FS client ops in the nfs_ssc_client_tbl
>> + * @ops: NFS_FS ops to be installed
>> + *
>> + * Return values:
>> + * None
>> + */
>> +void nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
>> +{
>> + nfs_ssc_client_tbl.ssc_nfs_ops = ops;
>> +}
>> +EXPORT_SYMBOL_GPL(nfs_ssc_register);
>> +
>> +/**
>> + * nfs_ssc_unregister - uninstall the NFS_FS client ops from
>> + * the nfs_ssc_client_tbl
>> + * @ops: ops to be uninstalled
>> + *
>> + * Return values:
>> + * None
>> + */
>> +void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops)
>> +{
>> + if (nfs_ssc_client_tbl.ssc_nfs_ops != ops)
>> + return;
>> + nfs_ssc_client_tbl.ssc_nfs_ops = NULL;
>> +}
>> +EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
>> +
>> +#else
>> +void nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
>> +{
>> +}
>> +EXPORT_SYMBOL_GPL(nfs_ssc_register);
>> +
>> +void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops)
>> +{
>> +}
>> +EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
>> +#endif /* CONFIG_NFS_V4_2 */
>> diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
>> index 99d2cae91bd6..f368f3215f88 100644
>> --- a/fs/nfsd/Kconfig
>> +++ b/fs/nfsd/Kconfig
>> @@ -136,7 +136,7 @@ config NFSD_FLEXFILELAYOUT
>>
>> config NFSD_V4_2_INTER_SSC
>> bool "NFSv4.2 inter server to server COPY"
>> - depends on NFSD_V4 && NFS_V4_1 && NFS_V4_2 && NFS_FS=y
>> + depends on NFSD_V4 && NFS_V4_1 && NFS_V4_2
>> help
>> This option enables support for NFSv4.2 inter server to
>> server copy where the destination server calls the NFSv4.2
>> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
>> index eaf50eafa935..84e10aef1417 100644
>> --- a/fs/nfsd/nfs4proc.c
>> +++ b/fs/nfsd/nfs4proc.c
>> @@ -38,6 +38,7 @@
>> #include <linux/slab.h>
>> #include <linux/kthread.h>
>> #include <linux/sunrpc/addr.h>
>> +#include <linux/nfs_ssc.h>
>>
>> #include "idmap.h"
>> #include "cache.h"
>> @@ -1247,7 +1248,7 @@ extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
>> static void
>> nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
>> {
>> - nfs_sb_deactive(ss_mnt->mnt_sb);
>> + nfs_do_sb_deactive(ss_mnt->mnt_sb);
>> mntput(ss_mnt);
>> }
>>
>> diff --git a/include/linux/nfs_ssc.h b/include/linux/nfs_ssc.h
>> new file mode 100644
>> index 000000000000..f5ba0fbff72f
>> --- /dev/null
>> +++ b/include/linux/nfs_ssc.h
>> @@ -0,0 +1,67 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * include/linux/nfs_ssc.h
>> + *
>> + * Author: Dai Ngo <dai.ngo@oracle.com>
>> + *
>> + * Copyright (c) 2020, Oracle and/or its affiliates.
>> + */
>> +
>> +#include <linux/nfs_fs.h>
>> +
>> +extern struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl;
>> +
>> +/*
>> + * NFS_V4
>> + */
>> +struct nfs4_ssc_client_ops {
>> + struct file *(*sco_open)(struct vfsmount *ss_mnt,
>> + struct nfs_fh *src_fh, nfs4_stateid *stateid);
>> + void (*sco_close)(struct file *filep);
>> +};
>> +
>> +/*
>> + * NFS_FS
>> + */
>> +struct nfs_ssc_client_ops {
>> + void (*sco_sb_deactive)(struct super_block *sb);
>> +};
>> +
>> +struct nfs_ssc_client_ops_tbl {
>> + const struct nfs4_ssc_client_ops *ssc_nfs4_ops;
>> + const struct nfs_ssc_client_ops *ssc_nfs_ops;
>> +};
>> +
>> +extern void nfs42_ssc_register_ops(void);
>> +extern void nfs42_ssc_unregister_ops(void);
>> +
>> +extern void nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops);
>> +extern void nfs42_ssc_unregister(const struct nfs4_ssc_client_ops *ops);
>> +
>> +#ifdef CONFIG_NFSD_V4_2_INTER_SSC
>> +static inline struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
>> + struct nfs_fh *src_fh, nfs4_stateid *stateid)
>> +{
>> + if (nfs_ssc_client_tbl.ssc_nfs4_ops)
>> + return (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_open)(ss_mnt, src_fh, stateid);
>> + return ERR_PTR(-EIO);
>> +}
>> +
>> +static inline void nfs42_ssc_close(struct file *filep)
>> +{
>> + if (nfs_ssc_client_tbl.ssc_nfs4_ops)
>> + (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_close)(filep);
>> +}
>> +#endif
>> +
>> +/*
>> + * NFS_FS
>> + */
>> +extern void nfs_ssc_register(const struct nfs_ssc_client_ops *ops);
>> +extern void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops);
>> +
>> +static inline void nfs_do_sb_deactive(struct super_block *sb)
>> +{
>> + if (nfs_ssc_client_tbl.ssc_nfs_ops)
>> + (*nfs_ssc_client_tbl.ssc_nfs_ops->sco_sb_deactive)(sb);
>> +}
>> --
>> 1.8.3.1
next prev parent reply other threads:[~2020-10-20 18:34 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-19 3:42 [PATCH v4 1/1] NFSv4.2: Fix NFS4ERR_STALE error when doing inter server copy Dai Ngo
2020-10-20 17:01 ` J. Bruce Fields
2020-10-20 18:34 ` Dai Ngo [this message]
2020-11-09 18:30 ` J. Bruce Fields
2020-11-09 19:34 ` Dai Ngo
2020-11-09 20:42 ` J. Bruce Fields
2020-11-09 22:26 ` Dai Ngo
2020-11-10 6:46 ` Dai Ngo
2020-11-10 20:12 ` J. Bruce Fields
2020-11-10 21:07 ` Olga Kornievskaia
2020-11-10 21:51 ` J. Bruce Fields
2020-11-10 22:08 ` Olga Kornievskaia
2020-11-10 22:21 ` J. Bruce Fields
2020-11-11 23:02 ` Dai Ngo
2020-11-23 16:25 ` J. Bruce Fields
2020-11-23 18:14 ` Dai Ngo
2020-11-23 22:08 ` J. Bruce Fields
2020-11-10 21:54 ` Dai Ngo
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