// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/nfs/callback_proc.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFSv4 callback procedures
*/
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "internal.h"
#include "pnfs.h"
#include "nfs4session.h"
#include "nfs4trace.h"
#define NFSDBG_FACILITY NFSDBG_CALLBACK
__be32 nfs4_callback_getattr(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_getattrargs *args = argp;
struct cb_getattrres *res = resp;
struct nfs_delegation *delegation;
struct inode *inode;
res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
goto out;
res->bitmap[0] = res->bitmap[1] = 0;
res->status = htonl(NFS4ERR_BADHANDLE);
dprintk_rcu("NFS: GETATTR callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
inode = nfs_delegation_find_inode(cps->clp, &args->fh);
if (IS_ERR(inode)) {
if (inode == ERR_PTR(-EAGAIN))
res->status = htonl(NFS4ERR_DELAY);
trace_nfs4_cb_getattr(cps->clp, &args->fh, NULL,
-ntohl(res->status));
goto out;
}
rcu_read_lock();
delegation = nfs4_get_valid_delegation(inode);
if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
goto out_iput;
res->size = i_size_read(inode);
res->change_attr = delegation->change_attr;
if (nfs_have_writebacks(inode))
res->change_attr++;
res->ctime = inode->i_ctime;
res->mtime = inode->i_mtime;
res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
args->bitmap[0];
res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
args->bitmap[1];
res->status = 0;
out_iput:
rcu_read_unlock();
trace_nfs4_cb_getattr(cps->clp, &args->fh, inode, -ntohl(res->status));
nfs_iput_and_deactive(inode);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
return res->status;
}
__be32 nfs4_callback_recall(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_recallargs *args = argp;
struct inode *inode;
__be32 res;
res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
goto out;
dprintk_rcu("NFS: RECALL callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
res = htonl(NFS4ERR_BADHANDLE);
inode = nfs_delegation_find_inode(cps->clp, &args->fh);
if (IS_ERR(inode)) {
if (inode == ERR_PTR(-EAGAIN))
res = htonl(NFS4ERR_DELAY);
trace_nfs4_cb_recall(cps->clp, &args->fh, NULL,
&args->stateid, -ntohl(res));
goto out;
}
/* Set up a helper thread to actually return the delegation */
switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
case 0:
res = 0;
break;
case -ENOENT:
res = htonl(NFS4ERR_BAD_STATEID);
break;
default:
res = htonl(NFS4ERR_RESOURCE);
}
trace_nfs4_cb_recall(cps->clp, &args->fh, inode,
&args->stateid, -ntohl(res));
nfs_iput_and_deactive(inode);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
return res;
}
#if defined(CONFIG_NFS_V4_1)
/*
* Lookup a layout inode by stateid
*
* Note: returns a refcount on the inode and superblock
*/
static struct inode *nfs_layout_find_inode_by_stateid(struct nfs_client *clp,
const nfs4_stateid *stateid)
{
struct nfs_server *server;
struct inode *inode;
struct pnfs_layout_hdr *lo;
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
list_for_each_entry(lo, &server->layouts, plh_layouts) {
if (stateid != NULL &&
!nfs4_stateid_match_other(stateid, &lo->plh_stateid))
continue;
inode = igrab(lo->plh_inode);
if (!inode)
return ERR_PTR(-EAGAIN);
if (!nfs_sb_active(inode->i_sb)) {
rcu_read_unlock();
spin_unlock(&clp->cl_lock);
iput(inode);
spin_lock(&clp->cl_lock);
rcu_read_lock();
return ERR_PTR(-EAGAIN);
}
return inode;
}
}
return ERR_PTR(-ENOENT);
}
/*
* Lookup a layout inode by filehandle.
*
* Note: returns a refcount on the inode and superblock
*
*/
static struct inode *nfs_layout_find_inode_by_fh(struct nfs_client *clp,
const struct nfs_fh *fh)
{
struct nfs_server *server;
struct nfs_inode *nfsi;
struct inode *inode;
struct pnfs_layout_hdr *lo;
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
list_for_each_entry(lo, &server->layouts, plh_layouts) {
nfsi = NFS_I(lo->plh_inode);
if (nfs_compare_fh(fh, &nfsi->fh))
continue;
if (nfsi->layout != lo)
continue;
inode = igrab(lo->plh_inode);
if (!inode)
return ERR_PTR(-EAGAIN);
if (!nfs_sb_active(inode->i_sb)) {
rcu_read_unlock();
spin_unlock(&clp->cl_lock);
iput(inode);
spin_lock(&clp->cl_lock);
rcu_read_lock();
return ERR_PTR(-EAGAIN);
}
return inode;
}
}
return ERR_PTR(-ENOENT);
}
static struct inode *nfs_layout_find_inode(struct nfs_client *clp,
const struct nfs_fh *fh,
const nfs4_stateid *stateid)
{
struct inode *inode;
spin_lock(&clp->cl_lock);
rcu_read_lock();
inode = nfs_layout_find_inode_by_stateid(clp, stateid);
if (inode == ERR_PTR(-ENOENT))
inode = nfs_layout_find_inode_by_fh(clp, fh);
rcu_read_unlock();
spin_unlock(&clp->cl_lock);
return inode;
}
/*
* Enforce RFC5661 section 12.5.5.2.1. (Layout Recall and Return Sequencing)
*/
static u32 pnfs_check_callback_stateid(struct pnfs_layout_hdr *lo,
const nfs4_stateid *new)
{
u32 oldseq, newseq;
/* Is the stateid not initialised? */
if (!pnfs_layout_is_valid(lo))
return NFS4ERR_NOMATCHING_LAYOUT;
/* Mismatched stateid? */
if (!nfs4_stateid_match_other(&lo->plh_stateid, new))
return NFS4ERR_BAD_STATEID;
newseq = be32_to_cpu(new->seqid);
/* Are we already in a layout recall situation? */
if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
lo->plh_return_seq != 0) {
if (newseq < lo->plh_return_seq)
return NFS4ERR_OLD_STATEID;
if (newseq > lo->plh_return_seq)
return NFS4ERR_DELAY;
goto out;
}
/* Check that the stateid matches what we think it should be. */
oldseq = be32_to_cpu(lo->plh_stateid.seqid);
if (newseq > oldseq + 1)
return NFS4ERR_DELAY;
/* Crazy server! */
if (newseq <= oldseq)
return NFS4ERR_OLD_STATEID;
out:
return NFS_OK;
}
static u32 initiate_file_draining(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
struct inode *ino;
struct pnfs_layout_hdr *lo;
u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
LIST_HEAD(free_me_list);
ino = nfs_layout_find_inode(clp, &args->cbl_fh, &args->cbl_stateid);
if (IS_ERR(ino)) {
if (ino == ERR_PTR(-EAGAIN))
rv = NFS4ERR_DELAY;
goto out_noput;
}
pnfs_layoutcommit_inode(ino, false);
spin_lock(&ino->i_lock);
lo = NFS_I(ino)->layout;
if (!lo) {
spin_unlock(&ino->i_lock);
goto out;
}
pnfs_get_layout_hdr(lo);
rv = pnfs_check_callback_stateid(lo, &args->cbl_stateid);
if (rv != NFS_OK)
goto unlock;
/*
* Enforce RFC5661 Section 12.5.5.2.1.5 (Bulk Recall and Return)
*/
if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
rv = NFS4ERR_DELAY;
goto unlock;
}
pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
switch (pnfs_mark_matching_lsegs_return(lo, &free_me_list,
&args->cbl_range,
be32_to_cpu(args->cbl_stateid.seqid))) {
case 0:
case -EBUSY:
/* There are layout segments that need to be returned */
rv = NFS4_OK;
break;
case -ENOENT:
/* Embrace your forgetfulness! */
rv = NFS4ERR_NOMATCHING_LAYOUT;
if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo,
&args->cbl_range);
}
}
unlock:
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&free_me_list);
/* Free all lsegs that are attached to commit buckets */
nfs_commit_inode(ino, 0);
pnfs_put_layout_hdr(lo);
out:
nfs_iput_and_deactive(ino);
out_noput:
trace_nfs4_cb_layoutrecall_file(clp, &args->cbl_fh, ino,
&args->cbl_stateid, -rv);
return rv;
}
static u32 initiate_bulk_draining(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
int stat;
if (args->cbl_recall_type == RETURN_FSID)
stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
else
stat = pnfs_destroy_layouts_byclid(clp, true);
if (stat != 0)
return NFS4ERR_DELAY;
return NFS4ERR_NOMATCHING_LAYOUT;
}
static u32 do_callback_layoutrecall(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
if (args->cbl_recall_type == RETURN_FILE)
return initiate_file_draining(clp, args);
return initiate_bulk_draining(clp, args);
}
__be32 nfs4_callback_layoutrecall(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_layoutrecallargs *args = argp;
u32 res = NFS4ERR_OP_NOT_IN_SESSION;
if (cps->clp)
res = do_callback_layoutrecall(cps->clp, args);
return cpu_to_be32(res);
}
static void pnfs_recall_all_layouts(struct nfs_client *clp)
{
struct cb_layoutrecallargs args;
/* Pretend we got a CB_LAYOUTRECALL(ALL) */
memset(&args, 0, sizeof(args));
args.cbl_recall_type = RETURN_ALL;
/* FIXME we ignore errors, what should we do? */
do_callback_layoutrecall(clp, &args);
}
__be32 nfs4_callback_devicenotify(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_devicenotifyargs *args = argp;
int i;
__be32 res = 0;
struct nfs_client *clp = cps->clp;
struct nfs_server *server = NULL;
if (!clp) {
res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
goto out;
}
for (i = 0; i < args->ndevs; i++) {
struct cb_devicenotifyitem *dev = &args->devs[i];
if (!server ||
server->pnfs_curr_ld->id != dev->cbd_layout_type) {
rcu_read_lock();
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
if (server->pnfs_curr_ld &&
server->pnfs_curr_ld->id == dev->cbd_layout_type) {
rcu_read_unlock();
goto found;
}
rcu_read_unlock();
continue;
}
found:
nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
}
out:
kfree(args->devs);
return res;
}
/*
* Validate the sequenceID sent by the server.
* Return success if the sequenceID is one more than what we last saw on
* this slot, accounting for wraparound. Increments the slot's sequence.
*
* We don't yet implement a duplicate request cache, instead we set the
* back channel ca_maxresponsesize_cached to zero. This is OK for now
* since we only currently implement idempotent callbacks anyway.
*
* We have a single slot backchannel at this time, so we don't bother
* checking the used_slots bit array on the table. The lower layer guarantees
* a single outstanding callback request at a time.
*/
static __be32
validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot,
const struct cb_sequenceargs * args)
{
__be32 ret;
ret = cpu_to_be32(NFS4ERR_BADSLOT);
if (args->csa_slotid > tbl->server_highest_slotid)
goto out_err;
/* Replay */
if (args->csa_sequenceid == slot->seq_nr) {
ret = cpu_to_be32(NFS4ERR_DELAY);
if (nfs4_test_locked_slot(tbl, slot->slot_nr))
goto out_err;
/* Signal process_op to set this error on next op */
ret = cpu_to_be32(NFS4ERR_RETRY_UNCACHED_REP);
if (args->csa_cachethis == 0)
goto out_err;
/* Liar! We never allowed you to set csa_cachethis != 0 */
ret = cpu_to_be32(NFS4ERR_SEQ_FALSE_RETRY);
goto out_err;
}
/* Note: wraparound relies on seq_nr being of type u32 */
/* Misordered request */
ret = cpu_to_be32(NFS4ERR_SEQ_MISORDERED);
if (args->csa_sequenceid != slot->seq_nr + 1)
goto out_err;
return cpu_to_be32(NFS4_OK);
out_err:
trace_nfs4_cb_seqid_err(args, ret);
return ret;
}
/*
* For each referring call triple, check the session's slot table for
* a match. If the slot is in use and the sequence numbers match, the
* client is still waiting for a response to the original request.
*/
static int referring_call_exists(struct nfs_client *clp,
uint32_t nrclists,
struct referring_call_list *rclists,
spinlock_t *lock)
__releases(lock)
__acquires(lock)
{
int status = 0;
int i, j;
struct nfs4_session *session;
struct nfs4_slot_table *tbl;
struct referring_call_list *rclist;
struct referring_call *ref;
/*
* XXX When client trunking is implemented, this becomes
* a session lookup from within the loop
*/
session = clp->cl_session;
tbl = &session->fc_slot_table;
for (i = 0; i < nrclists; i++) {
rclist = &rclists[i];
if (memcmp(session->sess_id.data,
rclist->rcl_sessionid.data,
NFS4_MAX_SESSIONID_LEN) != 0)
continue;
for (j = 0; j < rclist->rcl_nrefcalls; j++) {
ref = &rclist->rcl_refcalls[j];
spin_unlock(lock);
status = nfs4_slot_wait_on_seqid(tbl, ref->rc_slotid,
ref->rc_sequenceid, HZ >> 1) < 0;
spin_lock(lock);
if (status)
goto out;
}
}
out:
return status;
}
__be32 nfs4_callback_sequence(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_sequenceargs *args = argp;
struct cb_sequenceres *res = resp;
struct nfs4_slot_table *tbl;
struct nfs4_slot *slot;
struct nfs_client *clp;
int i;
__be32 status = htonl(NFS4ERR_BADSESSION);
clp = nfs4_find_client_sessionid(cps->net, args->csa_addr,
&args->csa_sessionid, cps->minorversion);
if (clp == NULL)
goto out;
if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
goto out;
tbl = &clp->cl_session->bc_slot_table;
/* Set up res before grabbing the spinlock */
memcpy(&res->csr_sessionid, &args->csa_sessionid,
sizeof(res->csr_sessionid));
res->csr_sequenceid = args->csa_sequenceid;
res->csr_slotid = args->csa_slotid;
spin_lock(&tbl->slot_tbl_lock);
/* state manager is resetting the session */
if (test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
status = htonl(NFS4ERR_DELAY);
/* Return NFS4ERR_BADSESSION if we're draining the session
* in order to reset it.
*/
if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
status = htonl(NFS4ERR_BADSESSION);
goto out_unlock;
}
status = htonl(NFS4ERR_BADSLOT);
slot = nfs4_lookup_slot(tbl, args->csa_slotid);
if (IS_ERR(slot))
goto out_unlock;
res->csr_highestslotid = tbl->server_highest_slotid;
res->csr_target_highestslotid = tbl->target_highest_slotid;
status = validate_seqid(tbl, slot, args);
if (status)
goto out_unlock;
if (!nfs4_try_to_lock_slot(tbl, slot)) {
status = htonl(NFS4ERR_DELAY);
goto out_unlock;
}
cps->slot = slot;
/* The ca_maxresponsesize_cached is 0 with no DRC */
if (args->csa_cachethis != 0) {
status = htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
goto out_unlock;
}
/*
* Check for pending referring calls. If a match is found, a
* related callback was received before the response to the original
* call.
*/
if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists,
&tbl->slot_tbl_lock) < 0) {
status = htonl(NFS4ERR_DELAY);
goto out_unlock;
}
/*
* RFC5661 20.9.3
* If CB_SEQUENCE returns an error, then the state of the slot
* (sequence ID, cached reply) MUST NOT change.
*/
slot->seq_nr = args->csa_sequenceid;
out_unlock:
spin_unlock(&tbl->slot_tbl_lock);
out:
cps->clp = clp; /* put in nfs4_callback_compound */
for (i = 0; i < args->csa_nrclists; i++)
kfree(args->csa_rclists[i].rcl_refcalls);
kfree(args->csa_rclists);
if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
cps->drc_status = status;
status = 0;
} else
res->csr_status = status;
trace_nfs4_cb_sequence(args, res, status);
return status;
}
static bool
validate_bitmap_values(unsigned int mask)
{
return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
}
__be32 nfs4_callback_recallany(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_recallanyargs *args = argp;
__be32 status;
fmode_t flags = 0;
status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
if (!cps->clp) /* set in cb_sequence */
goto out;
dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
status = cpu_to_be32(NFS4ERR_INVAL);
if (!validate_bitmap_values(args->craa_type_mask))
goto out;
status = cpu_to_be32(NFS4_OK);
if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_RDATA_DLG))
flags = FMODE_READ;
if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_WDATA_DLG))
flags |= FMODE_WRITE;
if (flags)
nfs_expire_unused_delegation_types(cps->clp, flags);
if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_FILE_LAYOUT))
pnfs_recall_all_layouts(cps->clp);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;
}
/* Reduce the fore channel's max_slots to the target value */
__be32 nfs4_callback_recallslot(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_recallslotargs *args = argp;
struct nfs4_slot_table *fc_tbl;
__be32 status;
status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
if (!cps->clp) /* set in cb_sequence */
goto out;
dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target highest slotid %u\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
args->crsa_target_highest_slotid);
fc_tbl = &cps->clp->cl_session->fc_slot_table;
status = htonl(NFS4_OK);
nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
nfs41_notify_server(cps->clp);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;
}
__be32 nfs4_callback_notify_lock(void *argp, void *resp,
struct cb_process_state *cps)
{
struct cb_notify_lock_args *args = argp;
if (!cps->clp) /* set in cb_sequence */
return htonl(NFS4ERR_OP_NOT_IN_SESSION);
dprintk_rcu("NFS: CB_NOTIFY_LOCK request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
/* Don't wake anybody if the string looked bogus */
if (args->cbnl_valid)
__wake_up(&cps->clp->cl_lock_waitq, TASK_NORMAL, 0, args);
return htonl(NFS4_OK);
}
#endif /* CONFIG_NFS_V4_1 */
#ifdef CONFIG_NFS_V4_2
static void nfs4_copy_cb_args(struct nfs4_copy_state *cp_state,
struct cb_offloadargs *args)
{
cp_state->count = args->wr_count;
cp_state->error = args->error;
if (!args->error) {
cp_state->verf.committed = args->wr_writeverf.committed;
memcpy(&cp_state->verf.verifier.data[0],
&args->wr_writeverf.verifier.data[0],
NFS4_VERIFIER_SIZE);
}
}
__be32 nfs4_callback_offload(void *data, void *dummy,
struct cb_process_state *cps)
{
struct cb_offloadargs *args = data;
struct nfs_server *server;
struct nfs4_copy_state *copy, *tmp_copy;
bool found = false;
copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
if (!copy)
return htonl(NFS4ERR_SERVERFAULT);
spin_lock(&cps->clp->cl_lock);
rcu_read_lock();
list_for_each_entry_rcu(server, &cps->clp->cl_superblocks,
client_link) {
list_for_each_entry(tmp_copy, &server->ss_copies, copies) {
if (memcmp(args->coa_stateid.other,
tmp_copy->stateid.other,
sizeof(args->coa_stateid.other)))
continue;
nfs4_copy_cb_args(tmp_copy, args);
complete(&tmp_copy->completion);
found = true;
goto out;
}
}
out:
rcu_read_unlock();
if (!found) {
memcpy(©->stateid, &args->coa_stateid, NFS4_STATEID_SIZE);
nfs4_copy_cb_args(copy, args);
list_add_tail(©->copies, &cps->clp->pending_cb_stateids);
} else
kfree(copy);
spin_unlock(&cps->clp->cl_lock);
return 0;
}
#endif /* CONFIG_NFS_V4_2 */