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1416 lines
38 KiB
1416 lines
38 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
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* linux/fs/nfs/delegation.c |
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* |
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* Copyright (C) 2004 Trond Myklebust |
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* |
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* NFS file delegation management |
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* |
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*/ |
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#include <linux/completion.h> |
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#include <linux/kthread.h> |
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#include <linux/module.h> |
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#include <linux/sched.h> |
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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#include <linux/iversion.h> |
|
|
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#include <linux/nfs4.h> |
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#include <linux/nfs_fs.h> |
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#include <linux/nfs_xdr.h> |
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|
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#include "nfs4_fs.h" |
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#include "nfs4session.h" |
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#include "delegation.h" |
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#include "internal.h" |
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#include "nfs4trace.h" |
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|
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#define NFS_DEFAULT_DELEGATION_WATERMARK (5000U) |
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|
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static atomic_long_t nfs_active_delegations; |
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static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK; |
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|
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static void __nfs_free_delegation(struct nfs_delegation *delegation) |
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{ |
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put_cred(delegation->cred); |
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delegation->cred = NULL; |
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kfree_rcu(delegation, rcu); |
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} |
|
|
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static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation) |
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{ |
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if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { |
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delegation->stateid.type = NFS4_INVALID_STATEID_TYPE; |
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atomic_long_dec(&nfs_active_delegations); |
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if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) |
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nfs_clear_verifier_delegated(delegation->inode); |
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} |
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} |
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|
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static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation) |
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{ |
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refcount_inc(&delegation->refcount); |
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return delegation; |
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} |
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|
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static void nfs_put_delegation(struct nfs_delegation *delegation) |
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{ |
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if (refcount_dec_and_test(&delegation->refcount)) |
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__nfs_free_delegation(delegation); |
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} |
|
|
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static void nfs_free_delegation(struct nfs_delegation *delegation) |
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{ |
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nfs_mark_delegation_revoked(delegation); |
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nfs_put_delegation(delegation); |
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} |
|
|
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/** |
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* nfs_mark_delegation_referenced - set delegation's REFERENCED flag |
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* @delegation: delegation to process |
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* |
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*/ |
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void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) |
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{ |
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set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); |
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} |
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|
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static bool |
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nfs4_is_valid_delegation(const struct nfs_delegation *delegation, |
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fmode_t flags) |
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{ |
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if (delegation != NULL && (delegation->type & flags) == flags && |
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!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && |
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!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) |
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return true; |
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return false; |
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} |
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|
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struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode) |
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{ |
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struct nfs_delegation *delegation; |
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|
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delegation = rcu_dereference(NFS_I(inode)->delegation); |
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if (nfs4_is_valid_delegation(delegation, 0)) |
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return delegation; |
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return NULL; |
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} |
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|
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static int |
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nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark) |
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{ |
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struct nfs_delegation *delegation; |
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int ret = 0; |
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|
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flags &= FMODE_READ|FMODE_WRITE; |
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rcu_read_lock(); |
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delegation = rcu_dereference(NFS_I(inode)->delegation); |
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if (nfs4_is_valid_delegation(delegation, flags)) { |
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if (mark) |
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nfs_mark_delegation_referenced(delegation); |
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ret = 1; |
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} |
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rcu_read_unlock(); |
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return ret; |
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} |
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/** |
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* nfs_have_delegation - check if inode has a delegation, mark it |
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* NFS_DELEGATION_REFERENCED if there is one. |
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* @inode: inode to check |
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* @flags: delegation types to check for |
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* |
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* Returns one if inode has the indicated delegation, otherwise zero. |
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*/ |
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int nfs4_have_delegation(struct inode *inode, fmode_t flags) |
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{ |
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return nfs4_do_check_delegation(inode, flags, true); |
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} |
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|
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/* |
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* nfs4_check_delegation - check if inode has a delegation, do not mark |
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* NFS_DELEGATION_REFERENCED if it has one. |
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*/ |
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int nfs4_check_delegation(struct inode *inode, fmode_t flags) |
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{ |
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return nfs4_do_check_delegation(inode, flags, false); |
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} |
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|
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static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid) |
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{ |
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struct inode *inode = state->inode; |
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struct file_lock *fl; |
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struct file_lock_context *flctx = inode->i_flctx; |
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struct list_head *list; |
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int status = 0; |
|
|
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if (flctx == NULL) |
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goto out; |
|
|
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list = &flctx->flc_posix; |
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spin_lock(&flctx->flc_lock); |
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restart: |
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list_for_each_entry(fl, list, fl_list) { |
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if (nfs_file_open_context(fl->fl_file)->state != state) |
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continue; |
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spin_unlock(&flctx->flc_lock); |
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status = nfs4_lock_delegation_recall(fl, state, stateid); |
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if (status < 0) |
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goto out; |
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spin_lock(&flctx->flc_lock); |
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} |
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if (list == &flctx->flc_posix) { |
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list = &flctx->flc_flock; |
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goto restart; |
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} |
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spin_unlock(&flctx->flc_lock); |
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out: |
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return status; |
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} |
|
|
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static int nfs_delegation_claim_opens(struct inode *inode, |
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const nfs4_stateid *stateid, fmode_t type) |
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{ |
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struct nfs_inode *nfsi = NFS_I(inode); |
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struct nfs_open_context *ctx; |
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struct nfs4_state_owner *sp; |
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struct nfs4_state *state; |
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unsigned int seq; |
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int err; |
|
|
|
again: |
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rcu_read_lock(); |
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list_for_each_entry_rcu(ctx, &nfsi->open_files, list) { |
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state = ctx->state; |
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if (state == NULL) |
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continue; |
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if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) |
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continue; |
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if (!nfs4_valid_open_stateid(state)) |
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continue; |
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if (!nfs4_stateid_match(&state->stateid, stateid)) |
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continue; |
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if (!get_nfs_open_context(ctx)) |
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continue; |
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rcu_read_unlock(); |
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sp = state->owner; |
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/* Block nfs4_proc_unlck */ |
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mutex_lock(&sp->so_delegreturn_mutex); |
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seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); |
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err = nfs4_open_delegation_recall(ctx, state, stateid); |
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if (!err) |
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err = nfs_delegation_claim_locks(state, stateid); |
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if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) |
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err = -EAGAIN; |
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mutex_unlock(&sp->so_delegreturn_mutex); |
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put_nfs_open_context(ctx); |
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if (err != 0) |
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return err; |
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goto again; |
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} |
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rcu_read_unlock(); |
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return 0; |
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} |
|
|
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/** |
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* nfs_inode_reclaim_delegation - process a delegation reclaim request |
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* @inode: inode to process |
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* @cred: credential to use for request |
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* @type: delegation type |
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* @stateid: delegation stateid |
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* @pagemod_limit: write delegation "space_limit" |
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* |
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*/ |
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void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred, |
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fmode_t type, |
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const nfs4_stateid *stateid, |
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unsigned long pagemod_limit) |
|
{ |
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struct nfs_delegation *delegation; |
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const struct cred *oldcred = NULL; |
|
|
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rcu_read_lock(); |
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delegation = rcu_dereference(NFS_I(inode)->delegation); |
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if (delegation != NULL) { |
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spin_lock(&delegation->lock); |
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if (nfs4_is_valid_delegation(delegation, 0)) { |
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nfs4_stateid_copy(&delegation->stateid, stateid); |
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delegation->type = type; |
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delegation->pagemod_limit = pagemod_limit; |
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oldcred = delegation->cred; |
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delegation->cred = get_cred(cred); |
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clear_bit(NFS_DELEGATION_NEED_RECLAIM, |
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&delegation->flags); |
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spin_unlock(&delegation->lock); |
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rcu_read_unlock(); |
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put_cred(oldcred); |
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trace_nfs4_reclaim_delegation(inode, type); |
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return; |
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} |
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/* We appear to have raced with a delegation return. */ |
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spin_unlock(&delegation->lock); |
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} |
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rcu_read_unlock(); |
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nfs_inode_set_delegation(inode, cred, type, stateid, pagemod_limit); |
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} |
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|
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static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) |
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{ |
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const struct cred *cred; |
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int res = 0; |
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|
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if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { |
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spin_lock(&delegation->lock); |
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cred = get_cred(delegation->cred); |
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spin_unlock(&delegation->lock); |
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res = nfs4_proc_delegreturn(inode, cred, |
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&delegation->stateid, |
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issync); |
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put_cred(cred); |
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} |
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return res; |
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} |
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|
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static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) |
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{ |
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struct inode *inode = NULL; |
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|
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spin_lock(&delegation->lock); |
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if (delegation->inode != NULL) |
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inode = igrab(delegation->inode); |
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if (!inode) |
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set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); |
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spin_unlock(&delegation->lock); |
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return inode; |
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} |
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|
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static struct nfs_delegation * |
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nfs_start_delegation_return_locked(struct nfs_inode *nfsi) |
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{ |
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struct nfs_delegation *ret = NULL; |
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struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); |
|
|
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if (delegation == NULL) |
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goto out; |
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spin_lock(&delegation->lock); |
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if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { |
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/* Refcount matched in nfs_end_delegation_return() */ |
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ret = nfs_get_delegation(delegation); |
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} |
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spin_unlock(&delegation->lock); |
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if (ret) |
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nfs_clear_verifier_delegated(&nfsi->vfs_inode); |
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out: |
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return ret; |
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} |
|
|
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static struct nfs_delegation * |
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nfs_start_delegation_return(struct nfs_inode *nfsi) |
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{ |
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struct nfs_delegation *delegation; |
|
|
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rcu_read_lock(); |
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delegation = nfs_start_delegation_return_locked(nfsi); |
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rcu_read_unlock(); |
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return delegation; |
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} |
|
|
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static void |
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nfs_abort_delegation_return(struct nfs_delegation *delegation, |
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struct nfs_client *clp) |
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{ |
|
|
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spin_lock(&delegation->lock); |
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clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); |
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set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
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spin_unlock(&delegation->lock); |
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set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); |
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} |
|
|
|
static struct nfs_delegation * |
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nfs_detach_delegation_locked(struct nfs_inode *nfsi, |
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struct nfs_delegation *delegation, |
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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); |
|
if (!delegation->inode) { |
|
spin_unlock(&delegation->lock); |
|
return NULL; |
|
} |
|
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; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(nfsi->delegation); |
|
if (delegation != NULL) |
|
delegation = nfs_detach_delegation(nfsi, delegation, server); |
|
rcu_read_unlock(); |
|
return delegation; |
|
} |
|
|
|
static void |
|
nfs_update_delegation_cred(struct nfs_delegation *delegation, |
|
const struct cred *cred) |
|
{ |
|
const struct cred *old; |
|
|
|
if (cred_fscmp(delegation->cred, cred) != 0) { |
|
old = xchg(&delegation->cred, get_cred(cred)); |
|
put_cred(old); |
|
} |
|
} |
|
|
|
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; |
|
delegation->pagemod_limit = update->pagemod_limit; |
|
if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { |
|
delegation->change_attr = update->change_attr; |
|
nfs_update_delegation_cred(delegation, update->cred); |
|
/* smp_mb__before_atomic() is implicit due to xchg() */ |
|
clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags); |
|
atomic_long_inc(&nfs_active_delegations); |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* 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 |
|
* @type: delegation type |
|
* @stateid: delegation stateid |
|
* @pagemod_limit: write delegation "space_limit" |
|
* |
|
* Returns zero on success, or a negative errno value. |
|
*/ |
|
int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, |
|
fmode_t type, |
|
const nfs4_stateid *stateid, |
|
unsigned long pagemod_limit) |
|
{ |
|
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, stateid); |
|
refcount_set(&delegation->refcount, 1); |
|
delegation->type = type; |
|
delegation->pagemod_limit = pagemod_limit; |
|
delegation->change_attr = inode_peek_iversion_raw(inode); |
|
delegation->cred = get_cred(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) |
|
goto add_new; |
|
/* Is this an update of the existing delegation? */ |
|
if (nfs4_stateid_match_other(&old_delegation->stateid, |
|
&delegation->stateid)) { |
|
spin_lock(&old_delegation->lock); |
|
nfs_update_inplace_delegation(old_delegation, |
|
delegation); |
|
spin_unlock(&old_delegation->lock); |
|
goto out; |
|
} |
|
if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) { |
|
/* |
|
* 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; |
|
add_new: |
|
list_add_tail_rcu(&delegation->super_list, &server->delegations); |
|
rcu_assign_pointer(nfsi->delegation, delegation); |
|
delegation = NULL; |
|
|
|
atomic_long_inc(&nfs_active_delegations); |
|
|
|
trace_nfs4_set_delegation(inode, type); |
|
|
|
spin_lock(&inode->i_lock); |
|
if (NFS_I(inode)->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME)) |
|
NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED; |
|
spin_unlock(&inode->i_lock); |
|
out: |
|
spin_unlock(&clp->cl_lock); |
|
if (delegation != NULL) |
|
__nfs_free_delegation(delegation); |
|
if (freeme != NULL) { |
|
nfs_do_return_delegation(inode, freeme, 0); |
|
nfs_free_delegation(freeme); |
|
} |
|
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; |
|
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, |
|
delegation->type); |
|
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; |
|
} |
|
|
|
err = nfs_do_return_delegation(inode, delegation, issync); |
|
out: |
|
/* Refcount matched in nfs_start_delegation_return_locked() */ |
|
nfs_put_delegation(delegation); |
|
return err; |
|
} |
|
|
|
static bool nfs_delegation_need_return(struct nfs_delegation *delegation) |
|
{ |
|
bool ret = false; |
|
|
|
if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) |
|
ret = true; |
|
else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) { |
|
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); |
|
} |
|
if (ret) |
|
clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); |
|
if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) || |
|
test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) |
|
ret = false; |
|
|
|
return ret; |
|
} |
|
|
|
static int nfs_server_return_marked_delegations(struct nfs_server *server, |
|
void __always_unused *data) |
|
{ |
|
struct nfs_delegation *delegation; |
|
struct nfs_delegation *prev; |
|
struct inode *inode; |
|
struct inode *place_holder = NULL; |
|
struct nfs_delegation *place_holder_deleg = NULL; |
|
int err = 0; |
|
|
|
restart: |
|
/* |
|
* To avoid quadratic looping we hold a reference |
|
* to an inode place_holder. Each time we restart, we |
|
* list delegation in the server from the delegations |
|
* of that inode. |
|
* prev is an RCU-protected pointer to a delegation which |
|
* wasn't marked for return and might be a good choice for |
|
* the next place_holder. |
|
*/ |
|
prev = NULL; |
|
delegation = NULL; |
|
rcu_read_lock(); |
|
if (place_holder) |
|
delegation = rcu_dereference(NFS_I(place_holder)->delegation); |
|
if (!delegation || delegation != place_holder_deleg) |
|
delegation = list_entry_rcu(server->delegations.next, |
|
struct nfs_delegation, super_list); |
|
list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { |
|
struct inode *to_put = NULL; |
|
|
|
if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) |
|
continue; |
|
if (!nfs_delegation_need_return(delegation)) { |
|
if (nfs4_is_valid_delegation(delegation, 0)) |
|
prev = delegation; |
|
continue; |
|
} |
|
|
|
if (prev) { |
|
struct inode *tmp = nfs_delegation_grab_inode(prev); |
|
if (tmp) { |
|
to_put = place_holder; |
|
place_holder = tmp; |
|
place_holder_deleg = prev; |
|
} |
|
} |
|
|
|
inode = nfs_delegation_grab_inode(delegation); |
|
if (inode == NULL) { |
|
rcu_read_unlock(); |
|
iput(to_put); |
|
goto restart; |
|
} |
|
delegation = nfs_start_delegation_return_locked(NFS_I(inode)); |
|
rcu_read_unlock(); |
|
|
|
iput(to_put); |
|
|
|
err = nfs_end_delegation_return(inode, delegation, 0); |
|
iput(inode); |
|
cond_resched(); |
|
if (!err) |
|
goto restart; |
|
set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); |
|
goto out; |
|
} |
|
rcu_read_unlock(); |
|
out: |
|
iput(place_holder); |
|
return err; |
|
} |
|
|
|
/** |
|
* 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) |
|
{ |
|
return nfs_client_for_each_server(clp, |
|
nfs_server_return_marked_delegations, NULL); |
|
} |
|
|
|
/** |
|
* nfs_inode_evict_delegation - 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(). Guaranteed to always free |
|
* the delegation structure. |
|
*/ |
|
void nfs_inode_evict_delegation(struct inode *inode) |
|
{ |
|
struct nfs_delegation *delegation; |
|
|
|
delegation = nfs_inode_detach_delegation(inode); |
|
if (delegation != NULL) { |
|
set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); |
|
set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); |
|
nfs_do_return_delegation(inode, delegation, 1); |
|
nfs_free_delegation(delegation); |
|
} |
|
} |
|
|
|
/** |
|
* 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; |
|
} |
|
|
|
/** |
|
* nfs_inode_return_delegation_on_close - asynchronously return a delegation |
|
* @inode: inode to process |
|
* |
|
* This routine is called on file close in order to determine if the |
|
* inode delegation needs to be returned immediately. |
|
*/ |
|
void nfs4_inode_return_delegation_on_close(struct inode *inode) |
|
{ |
|
struct nfs_delegation *delegation; |
|
struct nfs_delegation *ret = NULL; |
|
|
|
if (!inode) |
|
return; |
|
rcu_read_lock(); |
|
delegation = nfs4_get_valid_delegation(inode); |
|
if (!delegation) |
|
goto out; |
|
if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || |
|
atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { |
|
spin_lock(&delegation->lock); |
|
if (delegation->inode && |
|
list_empty(&NFS_I(inode)->open_files) && |
|
!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { |
|
clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); |
|
/* Refcount matched in nfs_end_delegation_return() */ |
|
ret = nfs_get_delegation(delegation); |
|
} |
|
spin_unlock(&delegation->lock); |
|
if (ret) |
|
nfs_clear_verifier_delegated(inode); |
|
} |
|
out: |
|
rcu_read_unlock(); |
|
nfs_end_delegation_return(inode, ret, 0); |
|
} |
|
|
|
/** |
|
* nfs4_inode_make_writeable |
|
* @inode: pointer to inode |
|
* |
|
* Make the inode writeable by returning the delegation if necessary |
|
* |
|
* Returns zero on success, or a negative errno value. |
|
*/ |
|
int nfs4_inode_make_writeable(struct inode *inode) |
|
{ |
|
struct nfs_delegation *delegation; |
|
|
|
rcu_read_lock(); |
|
delegation = nfs4_get_valid_delegation(inode); |
|
if (delegation == NULL || |
|
(nfs4_has_session(NFS_SERVER(inode)->nfs_client) && |
|
(delegation->type & FMODE_WRITE))) { |
|
rcu_read_unlock(); |
|
return 0; |
|
} |
|
rcu_read_unlock(); |
|
return nfs4_inode_return_delegation(inode); |
|
} |
|
|
|
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 |
|
* @server: pointer to nfs_server 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, |
|
const nfs4_stateid *stateid) |
|
{ |
|
struct nfs_delegation *delegation; |
|
nfs4_stateid tmp; |
|
bool ret = false; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(NFS_I(inode)->delegation); |
|
if (delegation == NULL) |
|
goto out; |
|
if (stateid == NULL) { |
|
nfs4_stateid_copy(&tmp, &delegation->stateid); |
|
stateid = &tmp; |
|
} else { |
|
if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) |
|
goto out; |
|
spin_lock(&delegation->lock); |
|
if (stateid->seqid) { |
|
if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { |
|
spin_unlock(&delegation->lock); |
|
goto out; |
|
} |
|
delegation->stateid.seqid = stateid->seqid; |
|
} |
|
spin_unlock(&delegation->lock); |
|
} |
|
nfs_mark_delegation_revoked(delegation); |
|
ret = true; |
|
out: |
|
rcu_read_unlock(); |
|
if (ret) |
|
nfs_inode_find_state_and_recover(inode, stateid); |
|
} |
|
|
|
void nfs_remove_bad_delegation(struct inode *inode, |
|
const nfs4_stateid *stateid) |
|
{ |
|
nfs_revoke_delegation(inode, stateid); |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); |
|
|
|
void nfs_delegation_mark_returned(struct inode *inode, |
|
const nfs4_stateid *stateid) |
|
{ |
|
struct nfs_delegation *delegation; |
|
|
|
if (!inode) |
|
return; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(NFS_I(inode)->delegation); |
|
if (!delegation) |
|
goto out_rcu_unlock; |
|
|
|
spin_lock(&delegation->lock); |
|
if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) |
|
goto out_spin_unlock; |
|
if (stateid->seqid) { |
|
/* If delegation->stateid is newer, dont mark as returned */ |
|
if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) |
|
goto out_clear_returning; |
|
if (delegation->stateid.seqid != stateid->seqid) |
|
delegation->stateid.seqid = stateid->seqid; |
|
} |
|
|
|
nfs_mark_delegation_revoked(delegation); |
|
|
|
out_clear_returning: |
|
clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); |
|
out_spin_unlock: |
|
spin_unlock(&delegation->lock); |
|
out_rcu_unlock: |
|
rcu_read_unlock(); |
|
|
|
nfs_inode_find_state_and_recover(inode, stateid); |
|
} |
|
|
|
/** |
|
* 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; |
|
|
|
rcu_read_lock(); |
|
delegation = nfs4_get_valid_delegation(inode); |
|
if (delegation == NULL) |
|
goto out_enoent; |
|
if (stateid != NULL && |
|
!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 super_block *freeme = NULL; |
|
struct inode *res = NULL; |
|
|
|
list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
|
spin_lock(&delegation->lock); |
|
if (delegation->inode != NULL && |
|
!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && |
|
nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { |
|
if (nfs_sb_active(server->super)) { |
|
freeme = server->super; |
|
res = igrab(delegation->inode); |
|
} |
|
spin_unlock(&delegation->lock); |
|
if (res != NULL) |
|
return res; |
|
if (freeme) { |
|
rcu_read_unlock(); |
|
nfs_sb_deactive(freeme); |
|
rcu_read_lock(); |
|
} |
|
return ERR_PTR(-EAGAIN); |
|
} |
|
spin_unlock(&delegation->lock); |
|
} |
|
return ERR_PTR(-ENOENT); |
|
} |
|
|
|
/** |
|
* 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; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { |
|
res = nfs_delegation_find_inode_server(server, fhandle); |
|
if (res != ERR_PTR(-ENOENT)) { |
|
rcu_read_unlock(); |
|
return res; |
|
} |
|
} |
|
rcu_read_unlock(); |
|
return ERR_PTR(-ENOENT); |
|
} |
|
|
|
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) { |
|
/* |
|
* If the delegation may have been admin revoked, then we |
|
* cannot reclaim it. |
|
*/ |
|
if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) |
|
continue; |
|
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(); |
|
} |
|
|
|
static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, |
|
void __always_unused *data) |
|
{ |
|
struct nfs_delegation *delegation; |
|
struct inode *inode; |
|
restart: |
|
rcu_read_lock(); |
|
restart_locked: |
|
list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
|
if (test_bit(NFS_DELEGATION_INODE_FREEING, |
|
&delegation->flags) || |
|
test_bit(NFS_DELEGATION_RETURNING, |
|
&delegation->flags) || |
|
test_bit(NFS_DELEGATION_NEED_RECLAIM, |
|
&delegation->flags) == 0) |
|
continue; |
|
inode = nfs_delegation_grab_inode(delegation); |
|
if (inode == NULL) |
|
goto restart_locked; |
|
delegation = nfs_start_delegation_return_locked(NFS_I(inode)); |
|
rcu_read_unlock(); |
|
if (delegation != NULL) { |
|
if (nfs_detach_delegation(NFS_I(inode), delegation, |
|
server) != NULL) |
|
nfs_free_delegation(delegation); |
|
/* Match nfs_start_delegation_return_locked */ |
|
nfs_put_delegation(delegation); |
|
} |
|
iput(inode); |
|
cond_resched(); |
|
goto restart; |
|
} |
|
rcu_read_unlock(); |
|
return 0; |
|
} |
|
|
|
/** |
|
* 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) |
|
{ |
|
nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, |
|
NULL); |
|
} |
|
|
|
static inline bool nfs4_server_rebooted(const struct nfs_client *clp) |
|
{ |
|
return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | |
|
BIT(NFS4CLNT_LEASE_EXPIRED) | |
|
BIT(NFS4CLNT_SESSION_RESET))) != 0; |
|
} |
|
|
|
static void nfs_mark_test_expired_delegation(struct nfs_server *server, |
|
struct nfs_delegation *delegation) |
|
{ |
|
if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) |
|
return; |
|
clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); |
|
set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); |
|
set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); |
|
} |
|
|
|
static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, |
|
struct inode *inode) |
|
{ |
|
struct nfs_delegation *delegation; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(NFS_I(inode)->delegation); |
|
if (delegation) |
|
nfs_mark_test_expired_delegation(server, delegation); |
|
rcu_read_unlock(); |
|
|
|
} |
|
|
|
static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) |
|
{ |
|
struct nfs_delegation *delegation; |
|
|
|
list_for_each_entry_rcu(delegation, &server->delegations, super_list) |
|
nfs_mark_test_expired_delegation(server, delegation); |
|
} |
|
|
|
/** |
|
* nfs_mark_test_expired_all_delegations - mark all delegations for testing |
|
* @clp: nfs_client to process |
|
* |
|
* Iterates through all the delegations associated with this server and |
|
* marks them as needing to be checked for validity. |
|
*/ |
|
void nfs_mark_test_expired_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_delegation_mark_test_expired_server(server); |
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* nfs_test_expired_all_delegations - test all delegations for a client |
|
* @clp: nfs_client to process |
|
* |
|
* Helper for handling "recallable state revoked" status from server. |
|
*/ |
|
void nfs_test_expired_all_delegations(struct nfs_client *clp) |
|
{ |
|
nfs_mark_test_expired_all_delegations(clp); |
|
nfs4_schedule_state_manager(clp); |
|
} |
|
|
|
static void |
|
nfs_delegation_test_free_expired(struct inode *inode, |
|
nfs4_stateid *stateid, |
|
const struct cred *cred) |
|
{ |
|
struct nfs_server *server = NFS_SERVER(inode); |
|
const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; |
|
int status; |
|
|
|
if (!cred) |
|
return; |
|
status = ops->test_and_free_expired(server, stateid, cred); |
|
if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) |
|
nfs_remove_bad_delegation(inode, stateid); |
|
} |
|
|
|
static int nfs_server_reap_expired_delegations(struct nfs_server *server, |
|
void __always_unused *data) |
|
{ |
|
struct nfs_delegation *delegation; |
|
struct inode *inode; |
|
const struct cred *cred; |
|
nfs4_stateid stateid; |
|
restart: |
|
rcu_read_lock(); |
|
restart_locked: |
|
list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
|
if (test_bit(NFS_DELEGATION_INODE_FREEING, |
|
&delegation->flags) || |
|
test_bit(NFS_DELEGATION_RETURNING, |
|
&delegation->flags) || |
|
test_bit(NFS_DELEGATION_TEST_EXPIRED, |
|
&delegation->flags) == 0) |
|
continue; |
|
inode = nfs_delegation_grab_inode(delegation); |
|
if (inode == NULL) |
|
goto restart_locked; |
|
spin_lock(&delegation->lock); |
|
cred = get_cred_rcu(delegation->cred); |
|
nfs4_stateid_copy(&stateid, &delegation->stateid); |
|
spin_unlock(&delegation->lock); |
|
clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); |
|
rcu_read_unlock(); |
|
nfs_delegation_test_free_expired(inode, &stateid, cred); |
|
put_cred(cred); |
|
if (!nfs4_server_rebooted(server->nfs_client)) { |
|
iput(inode); |
|
cond_resched(); |
|
goto restart; |
|
} |
|
nfs_inode_mark_test_expired_delegation(server,inode); |
|
iput(inode); |
|
return -EAGAIN; |
|
} |
|
rcu_read_unlock(); |
|
return 0; |
|
} |
|
|
|
/** |
|
* nfs_reap_expired_delegations - reap expired delegations |
|
* @clp: nfs_client to process |
|
* |
|
* Iterates through all the delegations associated with this server and |
|
* checks if they have may have been revoked. This function is usually |
|
* expected to be called in cases where the server may have lost its |
|
* lease. |
|
*/ |
|
void nfs_reap_expired_delegations(struct nfs_client *clp) |
|
{ |
|
nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, |
|
NULL); |
|
} |
|
|
|
void nfs_inode_find_delegation_state_and_recover(struct inode *inode, |
|
const nfs4_stateid *stateid) |
|
{ |
|
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; |
|
struct nfs_delegation *delegation; |
|
bool found = false; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(NFS_I(inode)->delegation); |
|
if (delegation && |
|
nfs4_stateid_match_or_older(&delegation->stateid, stateid) && |
|
!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { |
|
nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); |
|
found = true; |
|
} |
|
rcu_read_unlock(); |
|
if (found) |
|
nfs4_schedule_state_manager(clp); |
|
} |
|
|
|
/** |
|
* 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_refresh_delegation_stateid - Update delegation stateid seqid |
|
* @dst: stateid to refresh |
|
* @inode: inode to check |
|
* |
|
* Returns "true" and updates "dst->seqid" * if inode had a delegation |
|
* that matches our delegation stateid. Otherwise "false" is returned. |
|
*/ |
|
bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) |
|
{ |
|
struct nfs_delegation *delegation; |
|
bool ret = false; |
|
if (!inode) |
|
goto out; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(NFS_I(inode)->delegation); |
|
if (delegation != NULL && |
|
nfs4_stateid_match_other(dst, &delegation->stateid) && |
|
nfs4_stateid_is_newer(&delegation->stateid, dst) && |
|
!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { |
|
dst->seqid = delegation->stateid.seqid; |
|
ret = true; |
|
} |
|
rcu_read_unlock(); |
|
out: |
|
return ret; |
|
} |
|
|
|
/** |
|
* nfs4_copy_delegation_stateid - Copy inode's state ID information |
|
* @inode: inode to check |
|
* @flags: delegation type requirement |
|
* @dst: stateid data structure to fill in |
|
* @cred: optional argument to retrieve credential |
|
* |
|
* Returns "true" and fills in "dst->data" * if inode had a delegation, |
|
* otherwise "false" is returned. |
|
*/ |
|
bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, |
|
nfs4_stateid *dst, const struct cred **cred) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
struct nfs_delegation *delegation; |
|
bool ret = false; |
|
|
|
flags &= FMODE_READ|FMODE_WRITE; |
|
rcu_read_lock(); |
|
delegation = rcu_dereference(nfsi->delegation); |
|
if (!delegation) |
|
goto out; |
|
spin_lock(&delegation->lock); |
|
ret = nfs4_is_valid_delegation(delegation, flags); |
|
if (ret) { |
|
nfs4_stateid_copy(dst, &delegation->stateid); |
|
nfs_mark_delegation_referenced(delegation); |
|
if (cred) |
|
*cred = get_cred(delegation->cred); |
|
} |
|
spin_unlock(&delegation->lock); |
|
out: |
|
rcu_read_unlock(); |
|
return ret; |
|
} |
|
|
|
/** |
|
* nfs4_delegation_flush_on_close - Check if we must flush file on close |
|
* @inode: inode to check |
|
* |
|
* This function checks the number of outstanding writes to the file |
|
* against the delegation 'space_limit' field to see if |
|
* the spec requires us to flush the file on close. |
|
*/ |
|
bool nfs4_delegation_flush_on_close(const struct inode *inode) |
|
{ |
|
struct nfs_inode *nfsi = NFS_I(inode); |
|
struct nfs_delegation *delegation; |
|
bool ret = true; |
|
|
|
rcu_read_lock(); |
|
delegation = rcu_dereference(nfsi->delegation); |
|
if (delegation == NULL || !(delegation->type & FMODE_WRITE)) |
|
goto out; |
|
if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) |
|
ret = false; |
|
out: |
|
rcu_read_unlock(); |
|
return ret; |
|
} |
|
|
|
module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);
|
|
|