linux/fs/nfs/callback_proc.c
Fred Isaman f49f9baac8 pnfs: fix pnfs lock inversion of i_lock and cl_lock
The pnfs code was using throughout the lock order i_lock, cl_lock.
This conflicts with the nfs delegation code.  Rework the pnfs code
to avoid taking both locks simultaneously.

Currently the code takes the double lock to add/remove the layout to a
nfs_client list, while atomically checking that the list of lsegs is
empty.  To avoid this, we rely on existing serializations.  When a
layout is initialized with lseg count equal zero, LAYOUTGET's
openstateid serialization is in effect, making it safe to assume it
stays zero unless we change it.  And once a layout's lseg count drops
to zero, it is set as DESTROYED and so will stay at zero.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:40 -05:00

502 lines
13 KiB
C

/*
* 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 "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "internal.h"
#include "pnfs.h"
#ifdef NFS_DEBUG
#define NFSDBG_FACILITY NFSDBG_CALLBACK
#endif
__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("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)
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->npages != 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();
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("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)
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:
if (res != 0)
res = htonl(NFS4ERR_BAD_STATEID);
break;
default:
res = htonl(NFS4ERR_RESOURCE);
}
iput(inode);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
return res;
}
int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
{
if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
sizeof(delegation->stateid.data)) != 0)
return 0;
return 1;
}
#if defined(CONFIG_NFS_V4_1)
static u32 initiate_file_draining(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
struct pnfs_layout_hdr *lo;
struct inode *ino;
bool found = false;
u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
LIST_HEAD(free_me_list);
spin_lock(&clp->cl_lock);
list_for_each_entry(lo, &clp->cl_layouts, plh_layouts) {
if (nfs_compare_fh(&args->cbl_fh,
&NFS_I(lo->plh_inode)->fh))
continue;
ino = igrab(lo->plh_inode);
if (!ino)
continue;
found = true;
/* Without this, layout can be freed as soon
* as we release cl_lock.
*/
get_layout_hdr(lo);
break;
}
spin_unlock(&clp->cl_lock);
if (!found)
return NFS4ERR_NOMATCHING_LAYOUT;
spin_lock(&ino->i_lock);
if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
mark_matching_lsegs_invalid(lo, &free_me_list,
args->cbl_range.iomode))
rv = NFS4ERR_DELAY;
else
rv = NFS4ERR_NOMATCHING_LAYOUT;
pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&free_me_list);
put_layout_hdr(lo);
iput(ino);
return rv;
}
static u32 initiate_bulk_draining(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
struct pnfs_layout_hdr *lo;
struct inode *ino;
u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
struct pnfs_layout_hdr *tmp;
LIST_HEAD(recall_list);
LIST_HEAD(free_me_list);
struct pnfs_layout_range range = {
.iomode = IOMODE_ANY,
.offset = 0,
.length = NFS4_MAX_UINT64,
};
spin_lock(&clp->cl_lock);
list_for_each_entry(lo, &clp->cl_layouts, plh_layouts) {
if ((args->cbl_recall_type == RETURN_FSID) &&
memcmp(&NFS_SERVER(lo->plh_inode)->fsid,
&args->cbl_fsid, sizeof(struct nfs_fsid)))
continue;
if (!igrab(lo->plh_inode))
continue;
get_layout_hdr(lo);
BUG_ON(!list_empty(&lo->plh_bulk_recall));
list_add(&lo->plh_bulk_recall, &recall_list);
}
spin_unlock(&clp->cl_lock);
list_for_each_entry_safe(lo, tmp,
&recall_list, plh_bulk_recall) {
ino = lo->plh_inode;
spin_lock(&ino->i_lock);
set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
if (mark_matching_lsegs_invalid(lo, &free_me_list, range.iomode))
rv = NFS4ERR_DELAY;
list_del_init(&lo->plh_bulk_recall);
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&free_me_list);
put_layout_hdr(lo);
iput(ino);
}
return rv;
}
static u32 do_callback_layoutrecall(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
u32 res = NFS4ERR_DELAY;
dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
if (test_and_set_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state))
goto out;
if (args->cbl_recall_type == RETURN_FILE)
res = initiate_file_draining(clp, args);
else
res = initiate_bulk_draining(clp, args);
clear_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state);
out:
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);
}
int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
{
if (delegation == NULL)
return 0;
if (stateid->stateid.seqid != 0)
return 0;
if (memcmp(&delegation->stateid.stateid.other,
&stateid->stateid.other,
NFS4_STATEID_OTHER_SIZE))
return 0;
return 1;
}
/*
* 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(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
{
struct nfs4_slot *slot;
dprintk("%s enter. slotid %d seqid %d\n",
__func__, args->csa_slotid, args->csa_sequenceid);
if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS)
return htonl(NFS4ERR_BADSLOT);
slot = tbl->slots + args->csa_slotid;
dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
/* Normal */
if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
slot->seq_nr++;
return htonl(NFS4_OK);
}
/* Replay */
if (args->csa_sequenceid == slot->seq_nr) {
dprintk("%s seqid %d is a replay\n",
__func__, args->csa_sequenceid);
/* Signal process_op to set this error on next op */
if (args->csa_cachethis == 0)
return htonl(NFS4ERR_RETRY_UNCACHED_REP);
/* The ca_maxresponsesize_cached is 0 with no DRC */
else if (args->csa_cachethis == 1)
return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
}
/* Wraparound */
if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
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);
spin_lock(&tbl->slot_tbl_lock);
status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
tbl->slots[ref->rc_slotid].seq_nr ==
ref->rc_sequenceid);
spin_unlock(&tbl->slot_tbl_lock);
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 nfs_client *clp;
int i;
__be32 status = htonl(NFS4ERR_BADSESSION);
cps->clp = NULL;
clp = nfs4_find_client_sessionid(args->csa_addr, &args->csa_sessionid);
if (clp == NULL)
goto out;
/* state manager is resetting the session */
if (test_bit(NFS4_SESSION_DRAINING, &clp->cl_session->session_state)) {
status = NFS4ERR_DELAY;
goto out;
}
status = validate_seqid(&clp->cl_session->bc_slot_table, args);
if (status)
goto out;
/*
* 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;
}
memcpy(&res->csr_sessionid, &args->csa_sessionid,
sizeof(res->csr_sessionid));
res->csr_sequenceid = args->csa_sequenceid;
res->csr_slotid = args->csa_slotid;
res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
nfs4_cb_take_slot(clp);
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;
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("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_all_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("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
args->crsa_target_max_slots);
fc_tbl = &cps->clp->cl_session->fc_slot_table;
status = htonl(NFS4ERR_BAD_HIGH_SLOT);
if (args->crsa_target_max_slots > fc_tbl->max_slots ||
args->crsa_target_max_slots < 1)
goto out;
status = htonl(NFS4_OK);
if (args->crsa_target_max_slots == fc_tbl->max_slots)
goto out;
fc_tbl->target_max_slots = args->crsa_target_max_slots;
nfs41_handle_recall_slot(cps->clp);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;
}
#endif /* CONFIG_NFS_V4_1 */