From: Jeff Layton Date: Wed, 30 Jul 2014 12:27:23 +0000 (-0400) Subject: nfsd: add more granular locking to *_delegations fault injectors X-Git-Tag: firefly_0821_release~176^2~3426^2~16 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=98d5c7c5bd378aa1a22549200f49de3ed79d4d0a;p=firefly-linux-kernel-4.4.55.git nfsd: add more granular locking to *_delegations fault injectors ...instead of relying on the client_mutex. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c index d4472cd19807..2479dba71c3c 100644 --- a/fs/nfsd/fault_inject.c +++ b/fs/nfsd/fault_inject.c @@ -152,19 +152,15 @@ static struct nfsd_fault_inject_op inject_ops[] = { }, { .file = "forget_delegations", - .get = nfsd_inject_get, - .set_val = nfsd_inject_set, - .set_clnt = nfsd_inject_set_client, - .forget = nfsd_forget_client_delegations, - .print = nfsd_print_client_delegations, + .get = nfsd_inject_print_delegations, + .set_val = nfsd_inject_forget_delegations, + .set_clnt = nfsd_inject_forget_client_delegations, }, { .file = "recall_delegations", - .get = nfsd_inject_get, - .set_val = nfsd_inject_set, - .set_clnt = nfsd_inject_set_client, - .forget = nfsd_recall_client_delegations, - .print = nfsd_print_client_delegations, + .get = nfsd_inject_print_delegations, + .set_val = nfsd_inject_recall_delegations, + .set_clnt = nfsd_inject_recall_client_delegations, }, }; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 20bffa8c976c..d18bbb1e334d 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6102,9 +6102,13 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max, struct list_head *victims) { struct nfs4_delegation *dp, *next; + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); u64 count = 0; - lockdep_assert_held(&state_lock); + lockdep_assert_held(&nn->client_lock); + + spin_lock(&state_lock); list_for_each_entry_safe(dp, next, &clp->cl_delegations, dl_perclnt) { if (victims) { /* @@ -6116,62 +6120,180 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max, if (dp->dl_time != 0) continue; + atomic_inc(&clp->cl_refcount); unhash_delegation_locked(dp); list_add(&dp->dl_recall_lru, victims); } - if (++count == max) + ++count; + /* + * Despite the fact that these functions deal with + * 64-bit integers for "count", we must ensure that + * it doesn't blow up the clp->cl_refcount. Throw a + * warning if we start to approach INT_MAX here. + */ + WARN_ON_ONCE(count == (INT_MAX / 2)); + if (count == max) break; } + spin_unlock(&state_lock); return count; } -u64 nfsd_forget_client_delegations(struct nfs4_client *clp, u64 max) +static u64 +nfsd_print_client_delegations(struct nfs4_client *clp) { - struct nfs4_delegation *dp, *next; - LIST_HEAD(victims); - u64 count; + u64 count = nfsd_find_all_delegations(clp, 0, NULL); - spin_lock(&state_lock); - count = nfsd_find_all_delegations(clp, max, &victims); - spin_unlock(&state_lock); + nfsd_print_count(clp, count, "delegations"); + return count; +} + +u64 +nfsd_inject_print_delegations(struct nfsd_fault_inject_op *op) +{ + struct nfs4_client *clp; + u64 count = 0; + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); + + if (!nfsd_netns_ready(nn)) + return 0; - list_for_each_entry_safe(dp, next, &victims, dl_recall_lru) { + spin_lock(&nn->client_lock); + list_for_each_entry(clp, &nn->client_lru, cl_lru) + count += nfsd_print_client_delegations(clp); + spin_unlock(&nn->client_lock); + + return count; +} + +static void +nfsd_forget_delegations(struct list_head *reaplist) +{ + struct nfs4_client *clp; + struct nfs4_delegation *dp, *next; + + list_for_each_entry_safe(dp, next, reaplist, dl_recall_lru) { list_del_init(&dp->dl_recall_lru); + clp = dp->dl_stid.sc_client; revoke_delegation(dp); + put_client(clp); } +} + +u64 +nfsd_inject_forget_client_delegations(struct nfsd_fault_inject_op *op, + struct sockaddr_storage *addr, size_t addr_size) +{ + u64 count = 0; + struct nfs4_client *clp; + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); + LIST_HEAD(reaplist); + + if (!nfsd_netns_ready(nn)) + return count; + + spin_lock(&nn->client_lock); + clp = nfsd_find_client(addr, addr_size); + if (clp) + count = nfsd_find_all_delegations(clp, 0, &reaplist); + spin_unlock(&nn->client_lock); + + nfsd_forget_delegations(&reaplist); + return count; +} +u64 +nfsd_inject_forget_delegations(struct nfsd_fault_inject_op *op, u64 max) +{ + u64 count = 0; + struct nfs4_client *clp; + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); + LIST_HEAD(reaplist); + + if (!nfsd_netns_ready(nn)) + return count; + + spin_lock(&nn->client_lock); + list_for_each_entry(clp, &nn->client_lru, cl_lru) { + count += nfsd_find_all_delegations(clp, max - count, &reaplist); + if (max != 0 && count >= max) + break; + } + spin_unlock(&nn->client_lock); + nfsd_forget_delegations(&reaplist); return count; } -u64 nfsd_recall_client_delegations(struct nfs4_client *clp, u64 max) +static void +nfsd_recall_delegations(struct list_head *reaplist) { - struct nfs4_delegation *dp; - LIST_HEAD(victims); - u64 count; + struct nfs4_client *clp; + struct nfs4_delegation *dp, *next; - spin_lock(&state_lock); - count = nfsd_find_all_delegations(clp, max, &victims); - while (!list_empty(&victims)) { - dp = list_first_entry(&victims, struct nfs4_delegation, - dl_recall_lru); + list_for_each_entry_safe(dp, next, reaplist, dl_recall_lru) { list_del_init(&dp->dl_recall_lru); + clp = dp->dl_stid.sc_client; + /* + * We skipped all entries that had a zero dl_time before, + * so we can now reset the dl_time back to 0. If a delegation + * break comes in now, then it won't make any difference since + * we're recalling it either way. + */ + spin_lock(&state_lock); dp->dl_time = 0; + spin_unlock(&state_lock); nfsd_break_one_deleg(dp); + put_client(clp); } - spin_unlock(&state_lock); +} +u64 +nfsd_inject_recall_client_delegations(struct nfsd_fault_inject_op *op, + struct sockaddr_storage *addr, + size_t addr_size) +{ + u64 count = 0; + struct nfs4_client *clp; + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); + LIST_HEAD(reaplist); + + if (!nfsd_netns_ready(nn)) + return count; + + spin_lock(&nn->client_lock); + clp = nfsd_find_client(addr, addr_size); + if (clp) + count = nfsd_find_all_delegations(clp, 0, &reaplist); + spin_unlock(&nn->client_lock); + + nfsd_recall_delegations(&reaplist); return count; } -u64 nfsd_print_client_delegations(struct nfs4_client *clp, u64 max) +u64 +nfsd_inject_recall_delegations(struct nfsd_fault_inject_op *op, u64 max) { u64 count = 0; + struct nfs4_client *clp, *next; + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); + LIST_HEAD(reaplist); - spin_lock(&state_lock); - count = nfsd_find_all_delegations(clp, max, NULL); - spin_unlock(&state_lock); + if (!nfsd_netns_ready(nn)) + return count; - nfsd_print_count(clp, count, "delegations"); + spin_lock(&nn->client_lock); + list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) { + count += nfsd_find_all_delegations(clp, max - count, &reaplist); + if (max != 0 && ++count >= max) + break; + } + spin_unlock(&nn->client_lock); + nfsd_recall_delegations(&reaplist); return count; } @@ -6179,7 +6301,8 @@ u64 nfsd_for_n_state(u64 max, u64 (*func)(struct nfs4_client *, u64)) { struct nfs4_client *clp, *next; u64 count = 0; - struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, nfsd_net_id); + struct nfsd_net *nn = net_generic(current->nsproxy->net_ns, + nfsd_net_id); if (!nfsd_netns_ready(nn)) return 0; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index faaf6af7b28d..0a35e7bea5f7 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -493,10 +493,13 @@ u64 nfsd_inject_forget_client_openowners(struct nfsd_fault_inject_op *, struct sockaddr_storage *, size_t); u64 nfsd_inject_forget_openowners(struct nfsd_fault_inject_op *, u64); -u64 nfsd_forget_client_delegations(struct nfs4_client *, u64); -u64 nfsd_recall_client_delegations(struct nfs4_client *, u64); - -u64 nfsd_print_client_delegations(struct nfs4_client *, u64); +u64 nfsd_inject_print_delegations(struct nfsd_fault_inject_op *); +u64 nfsd_inject_forget_client_delegations(struct nfsd_fault_inject_op *, + struct sockaddr_storage *, size_t); +u64 nfsd_inject_forget_delegations(struct nfsd_fault_inject_op *, u64); +u64 nfsd_inject_recall_client_delegations(struct nfsd_fault_inject_op *, + struct sockaddr_storage *, size_t); +u64 nfsd_inject_recall_delegations(struct nfsd_fault_inject_op *, u64); #else /* CONFIG_NFSD_FAULT_INJECTION */ static inline int nfsd_fault_inject_init(void) { return 0; } static inline void nfsd_fault_inject_cleanup(void) {}