Message-ID: <4E087ABE.5090108@netapp.com>
Date: Mon, 27 Jun 2011 08:42:38 -0400
From: Bryan Schumaker <bjschuma@netapp.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
CC: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: [RFC v2] NFSD: Added basic fault injection
References: <4DD6AF42.5050502@netapp.com> <20110623195526.GA12357@fieldses.org>
In-Reply-To: <20110623195526.GA12357@fieldses.org>
Content-Type: text/plain; charset=ISO-8859-1
Sender: linux-nfs-owner@vger.kernel.org
MIME-Version: 1.0

On 06/23/2011 03:55 PM, J. Bruce Fields wrote:
> On Fri, May 20, 2011 at 02:13:22PM -0400, Bryan Schumaker wrote:
>> I have been looking at adding fault injection to the NFS server in order
>> to test the client's state manager and recovery threads.  Simulating
>> errors on the server seems like the easiest way to guarentee that
>> specific errors happen, and happen when we tell them to.
>>
>> This patch uses debugfs to add a simple framework for fault injection to
>> the server.  This framework is a config option, and can be enabled
>> through CONFIG_NFSD_FAULT_INJECTION.  Assuming you have debugfs mounted
>> to /sys/debug, a set of files will be created in /sys/debug/nfsd/.
>> Writing to any of these files will cause the corresponding action and
>> write a log entry to dmesg.
>>
>> Changes in v2:
>> - Replaced "forget all state owners" with "forget all open owners"
>> - Include fs/nfsd/fault_inject.c in the patch
>>
>> Suggestions?  Comments?
> 
> If this is still the most recent version of the patch, and if you can
> confirm that this has been tried and found useful for testing the
> client, then I'll go ahead and apply for 3.1.

Yes, this is the most recent version of the patch.  It is part of my Jenkins setup, but I haven't been running it on a regular basis recently.

- Bryan

> 
> --b.
> 
>>
>> - Bryan
>> ---
>> diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
>> index 18b3e89..8c02eab 100644
>> --- a/fs/nfsd/Kconfig
>> +++ b/fs/nfsd/Kconfig
>> @@ -91,3 +91,16 @@ config NFSD_V4
>>  	  available from http://linux-nfs.org/.
>>  
>>  	  If unsure, say N.
>> +
>> +config NFSD_FAULT_INJECTION
>> +	bool "NFS server manual fault injection"
>> +	depends on NFSD_V4 && DEBUG_KERNEL
>> +	help
>> +	  This option enables support for manually injecting faults
>> +	  into the NFS server.  This is intended to be used for
>> +	  testing error recovery on the NFS client.
>> +	  
>> +	  If unsure, say N.
>> +
>> +
>> +
>> diff --git a/fs/nfsd/Makefile b/fs/nfsd/Makefile
>> index 9b118ee..69eae75 100644
>> --- a/fs/nfsd/Makefile
>> +++ b/fs/nfsd/Makefile
>> @@ -5,7 +5,8 @@
>>  obj-$(CONFIG_NFSD)	+= nfsd.o
>>  
>>  nfsd-y 			:= nfssvc.o nfsctl.o nfsproc.o nfsfh.o vfs.o \
>> -			   export.o auth.o lockd.o nfscache.o nfsxdr.o stats.o
>> +			   export.o auth.o lockd.o nfscache.o nfsxdr.o stats.o \
>> +			   fault_inject.o
>>  nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o
>>  nfsd-$(CONFIG_NFSD_V3)	+= nfs3proc.o nfs3xdr.o
>>  nfsd-$(CONFIG_NFSD_V3_ACL) += nfs3acl.o
>> diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c
>> new file mode 100644
>> index 0000000..3dd1c32
>> --- /dev/null
>> +++ b/fs/nfsd/fault_inject.c
>> @@ -0,0 +1,106 @@
>> +
>> +#ifdef CONFIG_NFSD_FAULT_INJECTION
>> +
>> +#include <linux/types.h>
>> +#include <linux/fs.h>
>> +#include <linux/debugfs.h>
>> +#include <linux/module.h>
>> +
>> +#include "state.h"
>> +#include "nfsd.h"
>> +
>> +static void nfsd_forget_everything(void);
>> +
>> +struct nfsd_fault_inject_op {
>> +	char *name;
>> +	char *text;
>> +	int file_data;
>> +	void (*func)(void);
>> +};
>> +
>> +#define INJECTION_OP(op_name, op_text, op_func) \
>> +{				\
>> +	.name = op_name,	\
>> +	.text = op_text,	\
>> +	.func = op_func,	\
>> +}
>> +
>> +static struct nfsd_fault_inject_op inject_ops[] = {
>> +	INJECTION_OP("forget_clients",     "forget all clients",     nfsd_forget_all_clients),
>> +	INJECTION_OP("forget_locks",       "forget all locks",       nfsd_forget_all_locks),
>> +	INJECTION_OP("forget_open_owners", "forget all open owners", nfsd_forget_all_open_owners),
>> +	INJECTION_OP("forget_delegations", "forget all delegations", nfsd_forget_all_delegations),
>> +	INJECTION_OP("forget_everything",  "forget everything",      nfsd_forget_everything),
>> +	INJECTION_OP("recall_delegations", "recall all delegations", nfsd_recall_all_delegations),
>> +};
>> +
>> +static long int NUM_INJECT_OPS = sizeof(inject_ops) / sizeof(struct nfsd_fault_inject_op);
>> +static struct dentry *debug_dir;
>> +
>> +static void nfsd_forget_everything(void)
>> +{
>> +	nfsd_forget_all_clients();
>> +	nfsd_forget_all_locks();
>> +	nfsd_forget_all_open_owners();
>> +	nfsd_forget_all_delegations();
>> +}
>> +
>> +static int nfsd_inject_set(void *data, u64 val)
>> +{
>> +	int i;
>> +	for (i = 0; i < NUM_INJECT_OPS; i++) {
>> +		if (&inject_ops[i].file_data == data) {
>> +			printk(KERN_INFO "%s %s Server will %s", __FILE__, __func__, inject_ops[i].text);
>> +			inject_ops[i].func();
>> +		}
>> +	}
>> +	return 0;
>> +}
>> +
>> +static int nfsd_inject_get(void *data, u64 *val)
>> +{
>> +	return 0;
>> +}
>> +
>> +DEFINE_SIMPLE_ATTRIBUTE(fops_nfsd, nfsd_inject_get, nfsd_inject_set, "%llu\n");
>> +
>> +void
>> +nfsd_cleanup_fault_inject(void)
>> +{
>> +	debugfs_remove_recursive(debug_dir);
>> +}
>> +
>> +int
>> +nfsd_fault_inject_init(void)
>> +{
>> +	unsigned int i;
>> +	struct nfsd_fault_inject_op *op;
>> +	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
>> +
>> +	debug_dir = debugfs_create_dir("nfsd", NULL);
>> +	if (!debug_dir)
>> +		goto fail;
>> +
>> +	for (i = 0; i < NUM_INJECT_OPS; i++) {
>> +		op = &inject_ops[i];
>> +		debugfs_create_file(op->name, mode, debug_dir, &op->file_data, &fops_nfsd);
>> +	}
>> +	return 0;
>> +fail:
>> +	nfsd_cleanup_fault_inject();
>> +	return -ENOMEM;
>> +}
>> +
>> +#else /* CONFIG_NFSD_FAULT_INJECTION */
>> +
>> +inline void
>> +nfsd_cleanup_fault_inject(void)
>> +{}
>> +
>> +inline int
>> +nfsd_fault_inject_init(void)
>> +{
>> +	return 0;
>> +}
>> +
>> +#endif /* CONFIG_NFSD_FAULT_INJECTION */
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index 4cf04e1..f555e02 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -4274,6 +4274,144 @@ nfs4_check_open_reclaim(clientid_t *clid)
>>  	return nfs4_find_reclaim_client(clid) ? nfs_ok : nfserr_reclaim_bad;
>>  }
>>  
>> +#ifdef CONFIG_NFSD_FAULT_INJECTION
>> +
>> +void nfsd_forget_all_clients(void)
>> +{
>> +	struct nfs4_client *clp;
>> +	struct list_head *pos, *next, reaplist;
>> +	int count = 0;
>> +
>> +	nfs4_lock_state();
>> +	INIT_LIST_HEAD(&reaplist);
>> +
>> +	spin_lock(&client_lock);
>> +	list_for_each_safe(pos, next, &client_lru) {
>> +		clp = list_entry(pos, struct nfs4_client, cl_lru);
>> +		unhash_client_locked(clp);
>> +		list_add(&clp->cl_lru, &reaplist);
>> +		count ++;
>> +	}
>> +	spin_unlock(&client_lock);
>> +	list_for_each_safe(pos, next, &reaplist) {
>> +		clp = list_entry(pos, struct nfs4_client, cl_lru);
>> +		nfsd4_remove_clid_dir(clp);
>> +		expire_client(clp);
>> +	}
>> +
>> +	nfs4_unlock_state();
>> +	printk(KERN_INFO "%s %s Forgot %d clients", __FILE__, __func__, count);
>> +}
>> +
>> +void nfsd_forget_all_locks(void)
>> +{
>> +	struct nfs4_stateid *stp;
>> +	struct nfs4_stateowner *sop;
>> +	struct list_head reaplist;
>> +	int count = 0;
>> +	int i;
>> +
>> +	INIT_LIST_HEAD(&reaplist);
>> +	nfs4_lock_state();
>> +	for (i = 0; i < LOCK_HASH_SIZE; i++) {
>> +		list_for_each_entry(sop, &lock_ownerid_hashtbl[i], so_idhash) {
>> +			list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) {
>> +				list_add(&sop->so_perclient, &reaplist);
>> +			}
>> +		}
>> +	}
>> +
>> +	while (!list_empty(&reaplist)) {
>> +		sop = list_entry(reaplist.next, struct nfs4_stateowner, so_perclient);
>> +		list_del(&sop->so_perclient);
>> +		release_lockowner(sop);
>> +		count ++;
>> +	}
>> +	nfs4_unlock_state();
>> +
>> +	printk(KERN_INFO "%s %s Forgot %d locks", __FILE__, __func__, count);
>> +}
>> +
>> +void nfsd_forget_all_open_owners(void)
>> +{
>> +	struct nfs4_stateid *stp, *next;
>> +	unsigned int i;
>> +	int count = 0;
>> +
>> +	nfs4_lock_state();
>> +	for (i = 0; i < STATEID_HASH_SIZE; i++) {
>> +		list_for_each_entry_safe(stp, next, &stateid_hashtbl[i], st_hash) {
>> +			if (stp->st_openstp == NULL) {
>> +				release_openowner(stp->st_stateowner);
>> +				count++;
>> +			}
>> +		}
>> +	}
>> +	nfs4_unlock_state();
>> +	printk(KERN_INFO "%s %s Forgot %d open owners", __FILE__, __func__, count);
>> +}
>> +
>> +void nfsd_forget_all_delegations(void)
>> +{
>> +	struct nfs4_file *fp;
>> +	struct nfs4_delegation *dp;
>> +	struct list_head *pos, *next, reaplist;
>> +	unsigned int i;
>> +	unsigned int count = 0;
>> +
>> +	INIT_LIST_HEAD(&reaplist);
>> +
>> +	nfs4_lock_state();
>> +	spin_lock(&recall_lock);
>> +	for (i = 0; i < FILE_HASH_SIZE; i++) {
>> +		list_for_each_entry(fp, &file_hashtbl[i], fi_hash) {
>> +			list_for_each(pos, &fp->fi_delegations) {
>> +				dp = list_entry(pos, struct nfs4_delegation, dl_perfile);
>> +				list_del_init(&dp->dl_perclnt);
>> +				list_move(&dp->dl_recall_lru, &reaplist);
>> +			}
>> +		}
>> +	}
>> +
>> +	spin_unlock(&recall_lock);
>> +	list_for_each_safe(pos, next, &reaplist) {
>> +		dp = list_entry(pos, struct nfs4_delegation, dl_recall_lru);
>> +		list_del_init(&dp->dl_recall_lru);
>> +		unhash_delegation(dp);
>> +		count++;
>> +	}
>> +	nfs4_unlock_state();
>> +
>> +	printk(KERN_INFO "%s %s Forgot %d delegations", __FILE__, __func__, count);
>> +}
>> +
>> +void nfsd_recall_all_delegations(void)
>> +{
>> +	struct nfs4_file *fp;
>> +	struct nfs4_delegation *dp;
>> +	struct list_head *pos;
>> +	unsigned int i;
>> +	unsigned int count = 0;
>> +
>> +	nfs4_lock_state();
>> +	spin_lock(&recall_lock);
>> +	for (i = 0; i < FILE_HASH_SIZE; i++) {
>> +		list_for_each_entry(fp, &file_hashtbl[i], fi_hash) {
>> +			list_for_each(pos, &fp->fi_delegations) {
>> +				dp = list_entry(pos, struct nfs4_delegation, dl_perfile);
>> +				nfsd_break_one_deleg(dp);
>> +				count++;
>> +			}
>> +		}
>> +	}
>> +	spin_unlock(&recall_lock);
>> +	nfs4_unlock_state();
>> +	printk(KERN_INFO "%s %s Recalled %d delegations", __FILE__, __func__, count);
>> +}
>> +
>> +#endif /* CONFIG_NFSD_FAULT_INJECTION */
>> +
>> +
>>  /* initialization to perform at module load time: */
>>  
>>  int
>> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
>> index 1f5eae4..1eb3e92 100644
>> --- a/fs/nfsd/nfsctl.c
>> +++ b/fs/nfsd/nfsctl.c
>> @@ -1481,6 +1481,9 @@ static int __init init_nfsd(void)
>>  	retval = nfs4_state_init(); /* nfs4 locking state */
>>  	if (retval)
>>  		return retval;
>> +	retval = nfsd_fault_inject_init(); /* nfsd fault injection controls */
>> +	if (retval)
>> +		goto out_cleanup_fault_injection;
>>  	nfsd_stat_init();	/* Statistics */
>>  	retval = nfsd_reply_cache_init();
>>  	if (retval)
>> @@ -1512,6 +1515,8 @@ out_free_cache:
>>  out_free_stat:
>>  	nfsd_stat_shutdown();
>>  	nfsd4_free_slabs();
>> +out_cleanup_fault_injection:
>> +	nfsd_cleanup_fault_inject();
>>  	return retval;
>>  }
>>  
>> @@ -1525,6 +1530,7 @@ static void __exit exit_nfsd(void)
>>  	nfsd_lockd_shutdown();
>>  	nfsd_idmap_shutdown();
>>  	nfsd4_free_slabs();
>> +	nfsd_cleanup_fault_inject();
>>  	unregister_filesystem(&nfsd_fs_type);
>>  }
>>  
>> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
>> index 7ecfa24..4a6cded 100644
>> --- a/fs/nfsd/nfsd.h
>> +++ b/fs/nfsd/nfsd.h
>> @@ -79,11 +79,18 @@ static inline int nfsd_v4client(struct svc_rqst *rq)
>>  #ifdef CONFIG_NFSD_V4
>>  extern unsigned int max_delegations;
>>  int nfs4_state_init(void);
>> +int nfsd_fault_inject_init(void);
>> +void nfsd_cleanup_fault_inject(void);
>>  void nfsd4_free_slabs(void);
>>  int nfs4_state_start(void);
>>  void nfs4_state_shutdown(void);
>>  void nfs4_reset_lease(time_t leasetime);
>>  int nfs4_reset_recoverydir(char *recdir);
>> +void nfsd_forget_all_clients(void);
>> +void nfsd_forget_all_locks(void);
>> +void nfsd_forget_all_open_owners(void);
>> +void nfsd_forget_all_delegations(void);
>> +void nfsd_recall_all_delegations(void);
>>  #else
>>  static inline int nfs4_state_init(void) { return 0; }
>>  static inline void nfsd4_free_slabs(void) { }
>> @@ -91,6 +98,11 @@ static inline int nfs4_state_start(void) { return 0; }
>>  static inline void nfs4_state_shutdown(void) { }
>>  static inline void nfs4_reset_lease(time_t leasetime) { }
>>  static inline int nfs4_reset_recoverydir(char *recdir) { return 0; }
>> +static inline void nfsd_forget_all_clients(void) {};
>> +static inline void nfsd_forget_all_locks(void) {};
>> +static inline void nfsd_forget_all_open_owners(void) {};
>> +static inline void nfsd_forget_all_delegations(void) {};
>> +static inline void nfsd_recall_all_delegations(void) {};
>>  #endif
>>  
>>  /*