On 09/30/2011 10:35 AM, J. Bruce Fields wrote: > On Thu, Sep 29, 2011 at 02:59:23PM -0400, bjschuma@xxxxxxxxxx wrote: >> From: Bryan Schumaker <bjschuma@xxxxxxxxxx> >> >> Fault injection on the NFS server makes it easier to test the client's >> state manager and recovery threads. Simulating errors on the server is >> easier than finding the right conditions that cause them naturally. > > You also might look at the unlock_ip interface that Wendy Cheng added a > few years ago. The fact that it doesn't remove nfsv4 state is really a > bug, it should be blowing away any relevant v4 clients as the same time. > > (Though note the IP in question is a server IP, not a client IP.) I'll take a look. Thanks for the warning that it looks for a server IP, but would passing the client IP be more useful? > > Is this the forget_n_clients scenario really a useful one to test? > I'd've thought that the client would need to deal with the entire client > diseappearing (due to network partition, for example), but not normally > individual open owners. It might not be a normal case, but it still could be interesting to see how the client recovers. I was mostly looking at what state the server tracks and deleting what I could find. > > --b. > >> 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 v3: >> - Code cleanup and better use of generic functions >> - Allow the user to input the number of state objects to delete >> - Remove "forget_everything()" since forgetting a client is basically >> the same thing >> >> Changes in v2: >> - Replaced "forget all state owners" with "forget all open owners" >> - Include fs/nfsd/fault_inject.c in the patch >> >> Signed-off-by: Bryan Schumaker <bjschuma@xxxxxxxxxx> >> --- >> fs/nfsd/Kconfig | 10 ++++ >> fs/nfsd/Makefile | 3 +- >> fs/nfsd/fault_inject.c | 102 ++++++++++++++++++++++++++++++++++++++++++ >> fs/nfsd/nfs4state.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++ >> fs/nfsd/nfsctl.c | 6 +++ >> fs/nfsd/nfsd.h | 12 +++++ >> 6 files changed, 247 insertions(+), 1 deletions(-) >> create mode 100644 fs/nfsd/fault_inject.c >> >> diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig >> index 10e6366..52fdd1c 100644 >> --- a/fs/nfsd/Kconfig >> +++ b/fs/nfsd/Kconfig >> @@ -80,3 +80,13 @@ 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 injectiong 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..2139883 >> --- /dev/null >> +++ b/fs/nfsd/fault_inject.c >> @@ -0,0 +1,102 @@ >> +#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" >> + >> +struct nfsd_fault_inject_op { >> + char *action; >> + char *item; >> + char *file; >> + int file_data; >> + void (*func)(u64); >> +}; >> + >> +#define INJECTION_OP(op_action, op_item, op_func) \ >> +{ \ >> + .action = op_action, \ >> + .item = op_item, \ >> + .file = op_action"_"op_item, \ >> + .func = op_func, \ >> +} >> + >> +static struct nfsd_fault_inject_op inject_ops[] = { >> + INJECTION_OP("forget", "clients", nfsd_forget_clients), >> + INJECTION_OP("forget", "locks", nfsd_forget_locks), >> + INJECTION_OP("forget", "openowners", nfsd_forget_openowners), >> + INJECTION_OP("forget", "delegations", nfsd_forget_delegations), >> + INJECTION_OP("recall", "delegations", nfsd_recall_delegations), >> +}; >> + >> +static long int NUM_INJECT_OPS = sizeof(inject_ops) / sizeof(struct nfsd_fault_inject_op); >> +static struct dentry *debug_dir; >> + >> +static int nfsd_inject_set(void *data, u64 val) >> +{ >> + int i; >> + struct nfsd_fault_inject_op *op; >> + >> + for (i = 0; i < NUM_INJECT_OPS; i++) { >> + op = &inject_ops[i]; >> + if (&op->file_data == data) { >> + if (val == 0) { >> + printk(KERN_INFO "NFSD: Server %sing all %s", >> + op->action, op->item); >> + } else { >> + printk(KERN_INFO "NFSD: Server %sing at most %llu %s", >> + op->action, val, op->item); >> + } >> + op->func(val); >> + } >> + } >> + 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_fault_inject_cleanup(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->file, mode, debug_dir, &op->file_data, &fops_nfsd); >> + } >> + return 0; >> + >> +fail: >> + nfsd_fault_inject_cleanup(); >> + return -ENOMEM; >> +} >> + >> +#else /* CONFIG_NFSD_FAULT_INJECTION */ >> + >> +inline void nfsd_fault_inject_cleanup(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 05f4c69..64fa6b0 100644 >> --- a/fs/nfsd/nfs4state.c >> +++ b/fs/nfsd/nfs4state.c >> @@ -4358,6 +4358,121 @@ 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_clients(u64 num) >> +{ >> + struct nfs4_client *clp, *next; >> + int count = 0; >> + >> + nfs4_lock_state(); >> + list_for_each_entry_safe(clp, next, &client_lru, cl_lru) { >> + nfsd4_remove_clid_dir(clp); >> + expire_client(clp); >> + if (++count == num) >> + break; >> + } >> + nfs4_unlock_state(); >> + >> + printk(KERN_INFO "NFSD: Forgot %d clients", count); >> +} >> + >> +static void release_lockowner_sop(struct nfs4_stateowner *sop) >> +{ >> + release_lockowner(lockowner(sop)); >> +} >> + >> +static void release_openowner_sop(struct nfs4_stateowner *sop) >> +{ >> + release_openowner(openowner(sop)); >> +} >> + >> +static int nfsd_release_n_owners(u64 num, >> + struct list_head hashtbl[], >> + unsigned int hashtbl_size, >> + void (*release_sop)(struct nfs4_stateowner *)) >> +{ >> + int i, count = 0; >> + struct nfs4_stateowner *sop, *next; >> + >> + for (i = 0; i < hashtbl_size; i++) { >> + list_for_each_entry_safe(sop, next, &hashtbl[i], so_strhash) { >> + release_sop(sop); >> + if (++count == num) >> + return count; >> + } >> + } >> + return count; >> +} >> + >> +void nfsd_forget_locks(u64 num) >> +{ >> + int count; >> + >> + nfs4_lock_state(); >> + count = nfsd_release_n_owners(num, lock_ownerstr_hashtbl, >> + LOCK_HASH_SIZE, release_lockowner_sop); >> + nfs4_unlock_state(); >> + >> + printk(KERN_INFO "NFSD: Forgot %d locks", count); >> +} >> + >> +void nfsd_forget_openowners(u64 num) >> +{ >> + int count; >> + >> + nfs4_lock_state(); >> + count = nfsd_release_n_owners(num, open_ownerstr_hashtbl, >> + OPEN_OWNER_HASH_SIZE, release_openowner_sop); >> + nfs4_unlock_state(); >> + >> + printk(KERN_INFO "NFSD: Forgot %d open owners", count); >> +} >> + >> +int nfsd_process_n_delegations(u64 num, void (*deleg_func)(struct nfs4_delegation *)) >> +{ >> + int i, count = 0; >> + struct nfs4_file *fp; >> + struct nfs4_delegation *dp, *next; >> + >> + for (i = 0; i < FILE_HASH_SIZE; i++) { >> + list_for_each_entry(fp, &file_hashtbl[i], fi_hash) { >> + list_for_each_entry_safe(dp, next, &fp->fi_delegations, dl_perfile) { >> + deleg_func(dp); >> + if (++count == num) >> + return count; >> + } >> + } >> + } >> + return count; >> +} >> + >> +void nfsd_forget_delegations(u64 num) >> +{ >> + unsigned int count; >> + >> + nfs4_lock_state(); >> + count = nfsd_process_n_delegations(num, unhash_delegation); >> + nfs4_unlock_state(); >> + >> + printk(KERN_INFO "NFSD: Forgot %d delegations", count); >> +} >> + >> +void nfsd_recall_delegations(u64 num) >> +{ >> + unsigned int count; >> + >> + nfs4_lock_state(); >> + spin_lock(&recall_lock); >> + count = nfsd_process_n_delegations(num, nfsd_break_one_deleg); >> + spin_unlock(&recall_lock); >> + nfs4_unlock_state(); >> + >> + printk(KERN_INFO "NFSD: Recalled %d delegations", 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 db34a58..e2f1b5a 100644 >> --- a/fs/nfsd/nfsctl.c >> +++ b/fs/nfsd/nfsctl.c >> @@ -1130,6 +1130,9 @@ 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) >> @@ -1161,6 +1164,8 @@ out_free_cache: >> out_free_stat: >> nfsd_stat_shutdown(); >> nfsd4_free_slabs(); >> +out_cleanup_fault_injection: >> + nfsd_fault_inject_cleanup(); >> return retval; >> } >> >> @@ -1174,6 +1179,7 @@ static void __exit exit_nfsd(void) >> nfsd_lockd_shutdown(); >> nfsd_idmap_shutdown(); >> nfsd4_free_slabs(); >> + nfsd_fault_inject_cleanup(); >> unregister_filesystem(&nfsd_fs_type); >> } >> >> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h >> index 58134a2..3ea303d 100644 >> --- a/fs/nfsd/nfsd.h >> +++ b/fs/nfsd/nfsd.h >> @@ -105,11 +105,18 @@ 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_fault_inject_cleanup(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_clients(u64); >> +void nfsd_forget_locks(u64); >> +void nfsd_forget_openowners(u64); >> +void nfsd_forget_delegations(u64); >> +void nfsd_recall_delegations(u64); >> #else >> static inline int nfs4_state_init(void) { return 0; } >> static inline void nfsd4_free_slabs(void) { } >> @@ -117,6 +124,11 @@ 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_clients(u64) {} >> +static inline void nfsd_forget_locks(u64) {} >> +static inline void nfsd_forget_openowners(u64) {} >> +static inline void nfsd_forget_delegations(u64) {} >> +static inline void nfsd_recall_delegations(u64) {} >> #endif >> >> /* >> -- >> 1.7.6.4 >> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
