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. 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
