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linux/fs/nfs/callback_proc.c
Trond Myklebust 7b410d9ce4 pNFS: Delay getting the layout header in CB_LAYOUTRECALL handlers 
Instead of grabbing the layout, we want to get the inode so that we
can reduce races between layoutget and layoutrecall when the server
does not support call referring.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-12-01 17:21:42 -05:00

683 lines
18 KiB
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/*
* 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(struct cb_getattrargs *args,
struct cb_getattrres *res,
struct cb_process_state *cps)
{
struct nfs_delegation *delegation;
struct nfs_inode *nfsi;
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 (inode == NULL) {
trace_nfs4_cb_getattr(cps->clp, &args->fh, NULL,
-ntohl(res->status));
goto out;
}
nfsi = NFS_I(inode);
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
goto out_iput;
res->size = i_size_read(inode);
res->change_attr = delegation->change_attr;
if (nfsi->nrequests != 0)
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));
iput(inode);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
return res->status;
}
__be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
struct cb_process_state *cps)
{
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 (inode == NULL) {
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));
iput(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;
restart:
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)
continue;
if (!nfs_sb_active(inode->i_sb)) {
rcu_read_lock();
spin_unlock(&clp->cl_lock);
iput(inode);
spin_lock(&clp->cl_lock);
goto restart;
}
return inode;
}
}
return NULL;
}
/*
* 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;
restart:
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)
continue;
if (!nfs_sb_active(inode->i_sb)) {
rcu_read_lock();
spin_unlock(&clp->cl_lock);
iput(inode);
spin_lock(&clp->cl_lock);
goto restart;
}
return inode;
}
}
return NULL;
}
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)
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 still not initialised? */
if (!pnfs_layout_is_valid(lo))
return NFS4ERR_DELAY;
/* 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 (!ino)
goto out;
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;
pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
/*
* 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;
}
if (pnfs_mark_matching_lsegs_return(lo, &free_me_list,
&args->cbl_range,
be32_to_cpu(args->cbl_stateid.seqid))) {
rv = NFS4_OK;
goto unlock;
}
/* 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:
trace_nfs4_cb_layoutrecall_file(clp, &args->cbl_fh, ino,
&args->cbl_stateid, -rv);
nfs_iput_and_deactive(ino);
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)
{
u32 res;
dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
if (args->cbl_recall_type == RETURN_FILE)
res = initiate_file_draining(clp, args);
else
res = initiate_bulk_draining(clp, args);
dprintk("%s returning %i\n", __func__, res);
return res;
}
__be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
void *dummy, struct cb_process_state *cps)
{
u32 res;
dprintk("%s: -->\n", __func__);
if (cps->clp)
res = do_callback_layoutrecall(cps->clp, args);
else
res = NFS4ERR_OP_NOT_IN_SESSION;
dprintk("%s: exit with status = %d\n", __func__, res);
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(struct cb_devicenotifyargs *args,
void *dummy, struct cb_process_state *cps)
{
int i;
__be32 res = 0;
struct nfs_client *clp = cps->clp;
struct nfs_server *server = NULL;
dprintk("%s: -->\n", __func__);
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();
dprintk("%s: layout type %u not found\n",
__func__, dev->cbd_layout_type);
continue;
}
found:
nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
}
out:
kfree(args->devs);
dprintk("%s: exit with status = %u\n",
__func__, be32_to_cpu(res));
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)
{
dprintk("%s enter. slotid %u seqid %u, slot table seqid: %u\n",
__func__, args->csa_slotid, args->csa_sequenceid, slot->seq_nr);
if (args->csa_slotid > tbl->server_highest_slotid)
return htonl(NFS4ERR_BADSLOT);
/* Replay */
if (args->csa_sequenceid == slot->seq_nr) {
dprintk("%s seqid %u is a replay\n",
__func__, args->csa_sequenceid);
if (nfs4_test_locked_slot(tbl, slot->slot_nr))
return htonl(NFS4ERR_DELAY);
/* Signal process_op to set this error on next op */
if (args->csa_cachethis == 0)
return htonl(NFS4ERR_RETRY_UNCACHED_REP);
/* Liar! We never allowed you to set csa_cachethis != 0 */
return htonl(NFS4ERR_SEQ_FALSE_RETRY);
}
/* Wraparound */
if (unlikely(slot->seq_nr == 0xFFFFFFFFU)) {
if (args->csa_sequenceid == 1)
return htonl(NFS4_OK);
} else if (likely(args->csa_sequenceid == slot->seq_nr + 1))
return htonl(NFS4_OK);
/* Misordered request */
return htonl(NFS4ERR_SEQ_MISORDERED);
}
/*
* 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 bool referring_call_exists(struct nfs_client *clp,
uint32_t nrclists,
struct referring_call_list *rclists)
{
bool 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];
dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
"slotid %u\n", __func__,
((u32 *)&rclist->rcl_sessionid.data)[0],
((u32 *)&rclist->rcl_sessionid.data)[1],
((u32 *)&rclist->rcl_sessionid.data)[2],
((u32 *)&rclist->rcl_sessionid.data)[3],
ref->rc_sequenceid, ref->rc_slotid);
status = nfs4_slot_wait_on_seqid(tbl, ref->rc_slotid,
ref->rc_sequenceid, HZ >> 1) < 0;
if (status)
goto out;
}
}
out:
return status;
}
__be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
struct cb_sequenceres *res,
struct cb_process_state *cps)
{
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)) {
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);
dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
ntohl(status), ntohl(res->csr_status));
return status;
}
static bool
validate_bitmap_values(unsigned long mask)
{
return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
}
__be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
struct cb_process_state *cps)
{
__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 (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
&args->craa_type_mask))
flags = FMODE_READ;
if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
&args->craa_type_mask))
flags |= FMODE_WRITE;
if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
&args->craa_type_mask))
pnfs_recall_all_layouts(cps->clp);
if (flags)
nfs_expire_unused_delegation_types(cps->clp, flags);
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(struct cb_recallslotargs *args, void *dummy,
struct cb_process_state *cps)
{
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(struct cb_notify_lock_args *args, void *dummy,
struct cb_process_state *cps)
{
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 */
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