diff options
Diffstat (limited to 'kernel/fs/nfs/delegation.c')
| -rw-r--r-- | kernel/fs/nfs/delegation.c | 902 |
1 files changed, 902 insertions, 0 deletions
diff --git a/kernel/fs/nfs/delegation.c b/kernel/fs/nfs/delegation.c new file mode 100644 index 000000000..029d688a9 --- /dev/null +++ b/kernel/fs/nfs/delegation.c @@ -0,0 +1,902 @@ +/* + * linux/fs/nfs/delegation.c + * + * Copyright (C) 2004 Trond Myklebust + * + * NFS file delegation management + * + */ +#include <linux/completion.h> +#include <linux/kthread.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include <linux/nfs4.h> +#include <linux/nfs_fs.h> +#include <linux/nfs_xdr.h> + +#include "nfs4_fs.h" +#include "delegation.h" +#include "internal.h" +#include "nfs4trace.h" + +static void nfs_free_delegation(struct nfs_delegation *delegation) +{ + if (delegation->cred) { + put_rpccred(delegation->cred); + delegation->cred = NULL; + } + kfree_rcu(delegation, rcu); +} + +/** + * nfs_mark_delegation_referenced - set delegation's REFERENCED flag + * @delegation: delegation to process + * + */ +void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) +{ + set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); +} + +static int +nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark) +{ + struct nfs_delegation *delegation; + int ret = 0; + + flags &= FMODE_READ|FMODE_WRITE; + rcu_read_lock(); + delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation != NULL && (delegation->type & flags) == flags && + !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { + if (mark) + nfs_mark_delegation_referenced(delegation); + ret = 1; + } + rcu_read_unlock(); + return ret; +} +/** + * nfs_have_delegation - check if inode has a delegation, mark it + * NFS_DELEGATION_REFERENCED if there is one. + * @inode: inode to check + * @flags: delegation types to check for + * + * Returns one if inode has the indicated delegation, otherwise zero. + */ +int nfs4_have_delegation(struct inode *inode, fmode_t flags) +{ + return nfs4_do_check_delegation(inode, flags, true); +} + +/* + * nfs4_check_delegation - check if inode has a delegation, do not mark + * NFS_DELEGATION_REFERENCED if it has one. + */ +int nfs4_check_delegation(struct inode *inode, fmode_t flags) +{ + return nfs4_do_check_delegation(inode, flags, false); +} + +static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid) +{ + struct inode *inode = state->inode; + struct file_lock *fl; + struct file_lock_context *flctx = inode->i_flctx; + struct list_head *list; + int status = 0; + + if (flctx == NULL) + goto out; + + list = &flctx->flc_posix; + spin_lock(&flctx->flc_lock); +restart: + list_for_each_entry(fl, list, fl_list) { + if (nfs_file_open_context(fl->fl_file) != ctx) + continue; + spin_unlock(&flctx->flc_lock); + status = nfs4_lock_delegation_recall(fl, state, stateid); + if (status < 0) + goto out; + spin_lock(&flctx->flc_lock); + } + if (list == &flctx->flc_posix) { + list = &flctx->flc_flock; + goto restart; + } + spin_unlock(&flctx->flc_lock); +out: + return status; +} + +static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_open_context *ctx; + struct nfs4_state_owner *sp; + struct nfs4_state *state; + unsigned int seq; + int err; + +again: + spin_lock(&inode->i_lock); + list_for_each_entry(ctx, &nfsi->open_files, list) { + state = ctx->state; + if (state == NULL) + continue; + if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) + continue; + if (!nfs4_valid_open_stateid(state)) + continue; + if (!nfs4_stateid_match(&state->stateid, stateid)) + continue; + get_nfs_open_context(ctx); + spin_unlock(&inode->i_lock); + sp = state->owner; + /* Block nfs4_proc_unlck */ + mutex_lock(&sp->so_delegreturn_mutex); + seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); + err = nfs4_open_delegation_recall(ctx, state, stateid); + if (!err) + err = nfs_delegation_claim_locks(ctx, state, stateid); + if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) + err = -EAGAIN; + mutex_unlock(&sp->so_delegreturn_mutex); + put_nfs_open_context(ctx); + if (err != 0) + return err; + goto again; + } + spin_unlock(&inode->i_lock); + return 0; +} + +/** + * nfs_inode_reclaim_delegation - process a delegation reclaim request + * @inode: inode to process + * @cred: credential to use for request + * @res: new delegation state from server + * + */ +void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, + struct nfs_openres *res) +{ + struct nfs_delegation *delegation; + struct rpc_cred *oldcred = NULL; + + rcu_read_lock(); + delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation != NULL) { + spin_lock(&delegation->lock); + if (delegation->inode != NULL) { + nfs4_stateid_copy(&delegation->stateid, &res->delegation); + delegation->type = res->delegation_type; + delegation->maxsize = res->maxsize; + oldcred = delegation->cred; + delegation->cred = get_rpccred(cred); + clear_bit(NFS_DELEGATION_NEED_RECLAIM, + &delegation->flags); + spin_unlock(&delegation->lock); + rcu_read_unlock(); + put_rpccred(oldcred); + trace_nfs4_reclaim_delegation(inode, res->delegation_type); + } else { + /* We appear to have raced with a delegation return. */ + spin_unlock(&delegation->lock); + rcu_read_unlock(); + nfs_inode_set_delegation(inode, cred, res); + } + } else { + rcu_read_unlock(); + } +} + +static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) +{ + int res = 0; + + if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) + res = nfs4_proc_delegreturn(inode, + delegation->cred, + &delegation->stateid, + issync); + nfs_free_delegation(delegation); + return res; +} + +static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) +{ + struct inode *inode = NULL; + + spin_lock(&delegation->lock); + if (delegation->inode != NULL) + inode = igrab(delegation->inode); + spin_unlock(&delegation->lock); + return inode; +} + +static struct nfs_delegation * +nfs_start_delegation_return_locked(struct nfs_inode *nfsi) +{ + struct nfs_delegation *ret = NULL; + struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); + + if (delegation == NULL) + goto out; + spin_lock(&delegation->lock); + if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) + ret = delegation; + spin_unlock(&delegation->lock); +out: + return ret; +} + +static struct nfs_delegation * +nfs_start_delegation_return(struct nfs_inode *nfsi) +{ + struct nfs_delegation *delegation; + + rcu_read_lock(); + delegation = nfs_start_delegation_return_locked(nfsi); + rcu_read_unlock(); + return delegation; +} + +static void +nfs_abort_delegation_return(struct nfs_delegation *delegation, + struct nfs_client *clp) +{ + + spin_lock(&delegation->lock); + clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); + set_bit(NFS_DELEGATION_RETURN, &delegation->flags); + spin_unlock(&delegation->lock); + set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); +} + +static struct nfs_delegation * +nfs_detach_delegation_locked(struct nfs_inode *nfsi, + struct nfs_delegation *delegation, + struct nfs_client *clp) +{ + struct nfs_delegation *deleg_cur = + rcu_dereference_protected(nfsi->delegation, + lockdep_is_held(&clp->cl_lock)); + + if (deleg_cur == NULL || delegation != deleg_cur) + return NULL; + + spin_lock(&delegation->lock); + set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); + list_del_rcu(&delegation->super_list); + delegation->inode = NULL; + rcu_assign_pointer(nfsi->delegation, NULL); + spin_unlock(&delegation->lock); + return delegation; +} + +static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, + struct nfs_delegation *delegation, + struct nfs_server *server) +{ + struct nfs_client *clp = server->nfs_client; + + spin_lock(&clp->cl_lock); + delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); + spin_unlock(&clp->cl_lock); + return delegation; +} + +static struct nfs_delegation * +nfs_inode_detach_delegation(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_server *server = NFS_SERVER(inode); + struct nfs_delegation *delegation; + + delegation = nfs_start_delegation_return(nfsi); + if (delegation == NULL) + return NULL; + return nfs_detach_delegation(nfsi, delegation, server); +} + +static void +nfs_update_inplace_delegation(struct nfs_delegation *delegation, + const struct nfs_delegation *update) +{ + if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) { + delegation->stateid.seqid = update->stateid.seqid; + smp_wmb(); + delegation->type = update->type; + } +} + +/** + * nfs_inode_set_delegation - set up a delegation on an inode + * @inode: inode to which delegation applies + * @cred: cred to use for subsequent delegation processing + * @res: new delegation state from server + * + * Returns zero on success, or a negative errno value. + */ +int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res) +{ + struct nfs_server *server = NFS_SERVER(inode); + struct nfs_client *clp = server->nfs_client; + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_delegation *delegation, *old_delegation; + struct nfs_delegation *freeme = NULL; + int status = 0; + + delegation = kmalloc(sizeof(*delegation), GFP_NOFS); + if (delegation == NULL) + return -ENOMEM; + nfs4_stateid_copy(&delegation->stateid, &res->delegation); + delegation->type = res->delegation_type; + delegation->maxsize = res->maxsize; + delegation->change_attr = inode->i_version; + delegation->cred = get_rpccred(cred); + delegation->inode = inode; + delegation->flags = 1<<NFS_DELEGATION_REFERENCED; + spin_lock_init(&delegation->lock); + + spin_lock(&clp->cl_lock); + old_delegation = rcu_dereference_protected(nfsi->delegation, + lockdep_is_held(&clp->cl_lock)); + if (old_delegation != NULL) { + /* Is this an update of the existing delegation? */ + if (nfs4_stateid_match_other(&old_delegation->stateid, + &delegation->stateid)) { + nfs_update_inplace_delegation(old_delegation, + delegation); + goto out; + } + /* + * Deal with broken servers that hand out two + * delegations for the same file. + * Allow for upgrades to a WRITE delegation, but + * nothing else. + */ + dfprintk(FILE, "%s: server %s handed out " + "a duplicate delegation!\n", + __func__, clp->cl_hostname); + if (delegation->type == old_delegation->type || + !(delegation->type & FMODE_WRITE)) { + freeme = delegation; + delegation = NULL; + goto out; + } + if (test_and_set_bit(NFS_DELEGATION_RETURNING, + &old_delegation->flags)) + goto out; + freeme = nfs_detach_delegation_locked(nfsi, + old_delegation, clp); + if (freeme == NULL) + goto out; + } + list_add_tail_rcu(&delegation->super_list, &server->delegations); + rcu_assign_pointer(nfsi->delegation, delegation); + delegation = NULL; + + /* Ensure we revalidate the attributes and page cache! */ + spin_lock(&inode->i_lock); + nfsi->cache_validity |= NFS_INO_REVAL_FORCED; + spin_unlock(&inode->i_lock); + trace_nfs4_set_delegation(inode, res->delegation_type); + +out: + spin_unlock(&clp->cl_lock); + if (delegation != NULL) + nfs_free_delegation(delegation); + if (freeme != NULL) + nfs_do_return_delegation(inode, freeme, 0); + return status; +} + +/* + * Basic procedure for returning a delegation to the server + */ +static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) +{ + struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; + struct nfs_inode *nfsi = NFS_I(inode); + int err = 0; + + if (delegation == NULL) + return 0; + do { + if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) + break; + err = nfs_delegation_claim_opens(inode, &delegation->stateid); + if (!issync || err != -EAGAIN) + break; + /* + * Guard against state recovery + */ + err = nfs4_wait_clnt_recover(clp); + } while (err == 0); + + if (err) { + nfs_abort_delegation_return(delegation, clp); + goto out; + } + if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode))) + goto out; + + err = nfs_do_return_delegation(inode, delegation, issync); +out: + return err; +} + +static bool nfs_delegation_need_return(struct nfs_delegation *delegation) +{ + bool ret = false; + + if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) + goto out; + if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) + ret = true; + if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) { + struct inode *inode; + + spin_lock(&delegation->lock); + inode = delegation->inode; + if (inode && list_empty(&NFS_I(inode)->open_files)) + ret = true; + spin_unlock(&delegation->lock); + } +out: + return ret; +} + +/** + * nfs_client_return_marked_delegations - return previously marked delegations + * @clp: nfs_client to process + * + * Note that this function is designed to be called by the state + * manager thread. For this reason, it cannot flush the dirty data, + * since that could deadlock in case of a state recovery error. + * + * Returns zero on success, or a negative errno value. + */ +int nfs_client_return_marked_delegations(struct nfs_client *clp) +{ + struct nfs_delegation *delegation; + struct nfs_server *server; + struct inode *inode; + int err = 0; + +restart: + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { + list_for_each_entry_rcu(delegation, &server->delegations, + super_list) { + if (!nfs_delegation_need_return(delegation)) + continue; + if (!nfs_sb_active(server->super)) + continue; + inode = nfs_delegation_grab_inode(delegation); + if (inode == NULL) { + rcu_read_unlock(); + nfs_sb_deactive(server->super); + goto restart; + } + delegation = nfs_start_delegation_return_locked(NFS_I(inode)); + rcu_read_unlock(); + + err = nfs_end_delegation_return(inode, delegation, 0); + iput(inode); + nfs_sb_deactive(server->super); + if (!err) + goto restart; + set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); + return err; + } + } + rcu_read_unlock(); + return 0; +} + +/** + * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens + * @inode: inode to process + * + * Does not protect against delegation reclaims, therefore really only safe + * to be called from nfs4_clear_inode(). + */ +void nfs_inode_return_delegation_noreclaim(struct inode *inode) +{ + struct nfs_delegation *delegation; + + delegation = nfs_inode_detach_delegation(inode); + if (delegation != NULL) + nfs_do_return_delegation(inode, delegation, 1); +} + +/** + * nfs_inode_return_delegation - synchronously return a delegation + * @inode: inode to process + * + * This routine will always flush any dirty data to disk on the + * assumption that if we need to return the delegation, then + * we should stop caching. + * + * Returns zero on success, or a negative errno value. + */ +int nfs4_inode_return_delegation(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_delegation *delegation; + int err = 0; + + nfs_wb_all(inode); + delegation = nfs_start_delegation_return(nfsi); + if (delegation != NULL) + err = nfs_end_delegation_return(inode, delegation, 1); + return err; +} + +static void nfs_mark_return_if_closed_delegation(struct nfs_server *server, + struct nfs_delegation *delegation) +{ + set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); + set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); +} + +static void nfs_mark_return_delegation(struct nfs_server *server, + struct nfs_delegation *delegation) +{ + set_bit(NFS_DELEGATION_RETURN, &delegation->flags); + set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); +} + +static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) +{ + struct nfs_delegation *delegation; + bool ret = false; + + list_for_each_entry_rcu(delegation, &server->delegations, super_list) { + nfs_mark_return_delegation(server, delegation); + ret = true; + } + return ret; +} + +static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) +{ + struct nfs_server *server; + + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) + nfs_server_mark_return_all_delegations(server); + rcu_read_unlock(); +} + +static void nfs_delegation_run_state_manager(struct nfs_client *clp) +{ + if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) + nfs4_schedule_state_manager(clp); +} + +/** + * nfs_expire_all_delegations + * @clp: client to process + * + */ +void nfs_expire_all_delegations(struct nfs_client *clp) +{ + nfs_client_mark_return_all_delegations(clp); + nfs_delegation_run_state_manager(clp); +} + +/** + * nfs_super_return_all_delegations - return delegations for one superblock + * @sb: sb to process + * + */ +void nfs_server_return_all_delegations(struct nfs_server *server) +{ + struct nfs_client *clp = server->nfs_client; + bool need_wait; + + if (clp == NULL) + return; + + rcu_read_lock(); + need_wait = nfs_server_mark_return_all_delegations(server); + rcu_read_unlock(); + + if (need_wait) { + nfs4_schedule_state_manager(clp); + nfs4_wait_clnt_recover(clp); + } +} + +static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, + fmode_t flags) +{ + struct nfs_delegation *delegation; + + list_for_each_entry_rcu(delegation, &server->delegations, super_list) { + if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) + continue; + if (delegation->type & flags) + nfs_mark_return_if_closed_delegation(server, delegation); + } +} + +static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, + fmode_t flags) +{ + struct nfs_server *server; + + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) + nfs_mark_return_unused_delegation_types(server, flags); + rcu_read_unlock(); +} + +static void nfs_revoke_delegation(struct inode *inode) +{ + struct nfs_delegation *delegation; + rcu_read_lock(); + delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation != NULL) { + set_bit(NFS_DELEGATION_REVOKED, &delegation->flags); + nfs_mark_return_delegation(NFS_SERVER(inode), delegation); + } + rcu_read_unlock(); +} + +void nfs_remove_bad_delegation(struct inode *inode) +{ + struct nfs_delegation *delegation; + + nfs_revoke_delegation(inode); + delegation = nfs_inode_detach_delegation(inode); + if (delegation) { + nfs_inode_find_state_and_recover(inode, &delegation->stateid); + nfs_free_delegation(delegation); + } +} +EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); + +/** + * nfs_expire_unused_delegation_types + * @clp: client to process + * @flags: delegation types to expire + * + */ +void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) +{ + nfs_client_mark_return_unused_delegation_types(clp, flags); + nfs_delegation_run_state_manager(clp); +} + +static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) +{ + struct nfs_delegation *delegation; + + list_for_each_entry_rcu(delegation, &server->delegations, super_list) { + if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) + continue; + nfs_mark_return_if_closed_delegation(server, delegation); + } +} + +/** + * nfs_expire_unreferenced_delegations - Eliminate unused delegations + * @clp: nfs_client to process + * + */ +void nfs_expire_unreferenced_delegations(struct nfs_client *clp) +{ + struct nfs_server *server; + + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) + nfs_mark_return_unreferenced_delegations(server); + rcu_read_unlock(); + + nfs_delegation_run_state_manager(clp); +} + +/** + * nfs_async_inode_return_delegation - asynchronously return a delegation + * @inode: inode to process + * @stateid: state ID information + * + * Returns zero on success, or a negative errno value. + */ +int nfs_async_inode_return_delegation(struct inode *inode, + const nfs4_stateid *stateid) +{ + struct nfs_server *server = NFS_SERVER(inode); + struct nfs_client *clp = server->nfs_client; + struct nfs_delegation *delegation; + + filemap_flush(inode->i_mapping); + + rcu_read_lock(); + delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation == NULL) + goto out_enoent; + + if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) + goto out_enoent; + nfs_mark_return_delegation(server, delegation); + rcu_read_unlock(); + + nfs_delegation_run_state_manager(clp); + return 0; +out_enoent: + rcu_read_unlock(); + return -ENOENT; +} + +static struct inode * +nfs_delegation_find_inode_server(struct nfs_server *server, + const struct nfs_fh *fhandle) +{ + struct nfs_delegation *delegation; + struct inode *res = NULL; + + list_for_each_entry_rcu(delegation, &server->delegations, super_list) { + spin_lock(&delegation->lock); + if (delegation->inode != NULL && + nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { + res = igrab(delegation->inode); + } + spin_unlock(&delegation->lock); + if (res != NULL) + break; + } + return res; +} + +/** + * nfs_delegation_find_inode - retrieve the inode associated with a delegation + * @clp: client state handle + * @fhandle: filehandle from a delegation recall + * + * Returns pointer to inode matching "fhandle," or NULL if a matching inode + * cannot be found. + */ +struct inode *nfs_delegation_find_inode(struct nfs_client *clp, + const struct nfs_fh *fhandle) +{ + struct nfs_server *server; + struct inode *res = NULL; + + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { + res = nfs_delegation_find_inode_server(server, fhandle); + if (res != NULL) + break; + } + rcu_read_unlock(); + return res; +} + +static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) +{ + struct nfs_delegation *delegation; + + list_for_each_entry_rcu(delegation, &server->delegations, super_list) + set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); +} + +/** + * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed + * @clp: nfs_client to process + * + */ +void nfs_delegation_mark_reclaim(struct nfs_client *clp) +{ + struct nfs_server *server; + + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) + nfs_delegation_mark_reclaim_server(server); + rcu_read_unlock(); +} + +/** + * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done + * @clp: nfs_client to process + * + */ +void nfs_delegation_reap_unclaimed(struct nfs_client *clp) +{ + struct nfs_delegation *delegation; + struct nfs_server *server; + struct inode *inode; + +restart: + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { + list_for_each_entry_rcu(delegation, &server->delegations, + super_list) { + if (test_bit(NFS_DELEGATION_RETURNING, + &delegation->flags)) + continue; + if (test_bit(NFS_DELEGATION_NEED_RECLAIM, + &delegation->flags) == 0) + continue; + if (!nfs_sb_active(server->super)) + continue; + inode = nfs_delegation_grab_inode(delegation); + if (inode == NULL) { + rcu_read_unlock(); + nfs_sb_deactive(server->super); + goto restart; + } + delegation = nfs_start_delegation_return_locked(NFS_I(inode)); + rcu_read_unlock(); + if (delegation != NULL) { + delegation = nfs_detach_delegation(NFS_I(inode), + delegation, server); + if (delegation != NULL) + nfs_free_delegation(delegation); + } + iput(inode); + nfs_sb_deactive(server->super); + goto restart; + } + } + rcu_read_unlock(); +} + +/** + * nfs_delegations_present - check for existence of delegations + * @clp: client state handle + * + * Returns one if there are any nfs_delegation structures attached + * to this nfs_client. + */ +int nfs_delegations_present(struct nfs_client *clp) +{ + struct nfs_server *server; + int ret = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) + if (!list_empty(&server->delegations)) { + ret = 1; + break; + } + rcu_read_unlock(); + return ret; +} + +/** + * nfs4_copy_delegation_stateid - Copy inode's state ID information + * @dst: stateid data structure to fill in + * @inode: inode to check + * @flags: delegation type requirement + * + * Returns "true" and fills in "dst->data" * if inode had a delegation, + * otherwise "false" is returned. + */ +bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode, + fmode_t flags) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_delegation *delegation; + bool ret; + + flags &= FMODE_READ|FMODE_WRITE; + rcu_read_lock(); + delegation = rcu_dereference(nfsi->delegation); + ret = (delegation != NULL && (delegation->type & flags) == flags); + if (ret) { + nfs4_stateid_copy(dst, &delegation->stateid); + nfs_mark_delegation_referenced(delegation); + } + rcu_read_unlock(); + return ret; +} |