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linux-next/fs/nfsd/netns.h
J. Bruce Fields 027690c75e nfsd4: make drc_slab global, not per-net
I made every global per-network-namespace instead.  But perhaps doing
that to this slab was a step too far.

The kmem_cache_create call in our net init method also seems to be
responsible for this lockdep warning:

[   45.163710] Unable to find swap-space signature
[   45.375718] trinity-c1 (855): attempted to duplicate a private mapping with mremap.  This is not supported.
[   46.055744] futex_wake_op: trinity-c1 tries to shift op by -209; fix this program
[   51.011723]
[   51.013378] ======================================================
[   51.013875] WARNING: possible circular locking dependency detected
[   51.014378] 5.2.0-rc2 #1 Not tainted
[   51.014672] ------------------------------------------------------
[   51.015182] trinity-c2/886 is trying to acquire lock:
[   51.015593] 000000005405f099 (slab_mutex){+.+.}, at: slab_attr_store+0xa2/0x130
[   51.016190]
[   51.016190] but task is already holding lock:
[   51.016652] 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500
[   51.017266]
[   51.017266] which lock already depends on the new lock.
[   51.017266]
[   51.017909]
[   51.017909] the existing dependency chain (in reverse order) is:
[   51.018497]
[   51.018497] -> #1 (kn->count#43){++++}:
[   51.018956]        __lock_acquire+0x7cf/0x1a20
[   51.019317]        lock_acquire+0x17d/0x390
[   51.019658]        __kernfs_remove+0x892/0xae0
[   51.020020]        kernfs_remove_by_name_ns+0x78/0x110
[   51.020435]        sysfs_remove_link+0x55/0xb0
[   51.020832]        sysfs_slab_add+0xc1/0x3e0
[   51.021332]        __kmem_cache_create+0x155/0x200
[   51.021720]        create_cache+0xf5/0x320
[   51.022054]        kmem_cache_create_usercopy+0x179/0x320
[   51.022486]        kmem_cache_create+0x1a/0x30
[   51.022867]        nfsd_reply_cache_init+0x278/0x560
[   51.023266]        nfsd_init_net+0x20f/0x5e0
[   51.023623]        ops_init+0xcb/0x4b0
[   51.023928]        setup_net+0x2fe/0x670
[   51.024315]        copy_net_ns+0x30a/0x3f0
[   51.024653]        create_new_namespaces+0x3c5/0x820
[   51.025257]        unshare_nsproxy_namespaces+0xd1/0x240
[   51.025881]        ksys_unshare+0x506/0x9c0
[   51.026381]        __x64_sys_unshare+0x3a/0x50
[   51.026937]        do_syscall_64+0x110/0x10b0
[   51.027509]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   51.028175]
[   51.028175] -> #0 (slab_mutex){+.+.}:
[   51.028817]        validate_chain+0x1c51/0x2cc0
[   51.029422]        __lock_acquire+0x7cf/0x1a20
[   51.029947]        lock_acquire+0x17d/0x390
[   51.030438]        __mutex_lock+0x100/0xfa0
[   51.030995]        mutex_lock_nested+0x27/0x30
[   51.031516]        slab_attr_store+0xa2/0x130
[   51.032020]        sysfs_kf_write+0x11d/0x180
[   51.032529]        kernfs_fop_write+0x32a/0x500
[   51.033056]        do_loop_readv_writev+0x21d/0x310
[   51.033627]        do_iter_write+0x2e5/0x380
[   51.034148]        vfs_writev+0x170/0x310
[   51.034616]        do_pwritev+0x13e/0x160
[   51.035100]        __x64_sys_pwritev+0xa3/0x110
[   51.035633]        do_syscall_64+0x110/0x10b0
[   51.036200]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   51.036924]
[   51.036924] other info that might help us debug this:
[   51.036924]
[   51.037876]  Possible unsafe locking scenario:
[   51.037876]
[   51.038556]        CPU0                    CPU1
[   51.039130]        ----                    ----
[   51.039676]   lock(kn->count#43);
[   51.040084]                                lock(slab_mutex);
[   51.040597]                                lock(kn->count#43);
[   51.041062]   lock(slab_mutex);
[   51.041320]
[   51.041320]  *** DEADLOCK ***
[   51.041320]
[   51.041793] 3 locks held by trinity-c2/886:
[   51.042128]  #0: 000000001f55e152 (sb_writers#5){.+.+}, at: vfs_writev+0x2b9/0x310
[   51.042739]  #1: 00000000c7d6c034 (&of->mutex){+.+.}, at: kernfs_fop_write+0x25b/0x500
[   51.043400]  #2: 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3ba75830ce "drc containerization"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-06-01 17:44:45 -04:00

188 lines
4.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* per net namespace data structures for nfsd
*
* Copyright (C) 2012, Jeff Layton <jlayton@redhat.com>
*/
#ifndef __NFSD_NETNS_H__
#define __NFSD_NETNS_H__
#include <net/net_namespace.h>
#include <net/netns/generic.h>
/* Hash tables for nfs4_clientid state */
#define CLIENT_HASH_BITS 4
#define CLIENT_HASH_SIZE (1 << CLIENT_HASH_BITS)
#define CLIENT_HASH_MASK (CLIENT_HASH_SIZE - 1)
#define SESSION_HASH_SIZE 512
struct cld_net;
struct nfsd4_client_tracking_ops;
/*
* Represents a nfsd "container". With respect to nfsv4 state tracking, the
* fields of interest are the *_id_hashtbls and the *_name_tree. These track
* the nfs4_client objects by either short or long form clientid.
*
* Each nfsd_net runs a nfs4_laundromat workqueue job when necessary to clean
* up expired clients and delegations within the container.
*/
struct nfsd_net {
struct cld_net *cld_net;
struct cache_detail *svc_expkey_cache;
struct cache_detail *svc_export_cache;
struct cache_detail *idtoname_cache;
struct cache_detail *nametoid_cache;
struct lock_manager nfsd4_manager;
bool grace_ended;
time64_t boot_time;
/* internal mount of the "nfsd" pseudofilesystem: */
struct vfsmount *nfsd_mnt;
struct dentry *nfsd_client_dir;
/*
* reclaim_str_hashtbl[] holds known client info from previous reset/reboot
* used in reboot/reset lease grace period processing
*
* conf_id_hashtbl[], and conf_name_tree hold confirmed
* setclientid_confirmed info.
*
* unconf_str_hastbl[] and unconf_name_tree hold unconfirmed
* setclientid info.
*/
struct list_head *reclaim_str_hashtbl;
int reclaim_str_hashtbl_size;
struct list_head *conf_id_hashtbl;
struct rb_root conf_name_tree;
struct list_head *unconf_id_hashtbl;
struct rb_root unconf_name_tree;
struct list_head *sessionid_hashtbl;
/*
* client_lru holds client queue ordered by nfs4_client.cl_time
* for lease renewal.
*
* close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
* for last close replay.
*
* All of the above fields are protected by the client_mutex.
*/
struct list_head client_lru;
struct list_head close_lru;
struct list_head del_recall_lru;
/* protected by blocked_locks_lock */
struct list_head blocked_locks_lru;
struct delayed_work laundromat_work;
/* client_lock protects the client lru list and session hash table */
spinlock_t client_lock;
/* protects blocked_locks_lru */
spinlock_t blocked_locks_lock;
struct file *rec_file;
bool in_grace;
const struct nfsd4_client_tracking_ops *client_tracking_ops;
time64_t nfsd4_lease;
time64_t nfsd4_grace;
bool somebody_reclaimed;
bool track_reclaim_completes;
atomic_t nr_reclaim_complete;
bool nfsd_net_up;
bool lockd_up;
/* Time of server startup */
struct timespec64 nfssvc_boot;
seqlock_t boot_lock;
/*
* Max number of connections this nfsd container will allow. Defaults
* to '0' which is means that it bases this on the number of threads.
*/
unsigned int max_connections;
u32 clientid_base;
u32 clientid_counter;
u32 clverifier_counter;
struct svc_serv *nfsd_serv;
wait_queue_head_t ntf_wq;
atomic_t ntf_refcnt;
/*
* clientid and stateid data for construction of net unique COPY
* stateids.
*/
u32 s2s_cp_cl_id;
struct idr s2s_cp_stateids;
spinlock_t s2s_cp_lock;
/*
* Version information
*/
bool *nfsd_versions;
bool *nfsd4_minorversions;
/*
* Duplicate reply cache
*/
struct nfsd_drc_bucket *drc_hashtbl;
/* max number of entries allowed in the cache */
unsigned int max_drc_entries;
/* number of significant bits in the hash value */
unsigned int maskbits;
unsigned int drc_hashsize;
/*
* Stats and other tracking of on the duplicate reply cache.
* These fields and the "rc" fields in nfsdstats are modified
* with only the per-bucket cache lock, which isn't really safe
* and should be fixed if we want the statistics to be
* completely accurate.
*/
/* total number of entries */
atomic_t num_drc_entries;
/* cache misses due only to checksum comparison failures */
unsigned int payload_misses;
/* amount of memory (in bytes) currently consumed by the DRC */
unsigned int drc_mem_usage;
/* longest hash chain seen */
unsigned int longest_chain;
/* size of cache when we saw the longest hash chain */
unsigned int longest_chain_cachesize;
struct shrinker nfsd_reply_cache_shrinker;
/* utsname taken from the the process that starts the server */
char nfsd_name[UNX_MAXNODENAME+1];
};
/* Simple check to find out if a given net was properly initialized */
#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
extern void nfsd_netns_free_versions(struct nfsd_net *nn);
extern unsigned int nfsd_net_id;
void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn);
void nfsd_reset_boot_verifier(struct nfsd_net *nn);
#endif /* __NFSD_NETNS_H__ */