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pnfs.c
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/*
* pNFS functions to call and manage layout drivers.
*
* Copyright (c) 2002 [year of first publication]
* The Regents of the University of Michigan
* All Rights Reserved
*
* Dean Hildebrand <[email protected]>
*
* Permission is granted to use, copy, create derivative works, and
* redistribute this software and such derivative works for any purpose,
* so long as the name of the University of Michigan is not used in
* any advertising or publicity pertaining to the use or distribution
* of this software without specific, written prior authorization. If
* the above copyright notice or any other identification of the
* University of Michigan is included in any copy of any portion of
* this software, then the disclaimer below must also be included.
*
* This software is provided as is, without representation or warranty
* of any kind either express or implied, including without limitation
* the implied warranties of merchantability, fitness for a particular
* purpose, or noninfringement. The Regents of the University of
* Michigan shall not be liable for any damages, including special,
* indirect, incidental, or consequential damages, with respect to any
* claim arising out of or in connection with the use of the software,
* even if it has been or is hereafter advised of the possibility of
* such damages.
*/
#include <linux/nfs_fs.h>
#include "internal.h"
#include "pnfs.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_PNFS
/* Locking:
*
* pnfs_spinlock:
* protects pnfs_modules_tbl.
*/
static DEFINE_SPINLOCK(pnfs_spinlock);
/*
* pnfs_modules_tbl holds all pnfs modules
*/
static LIST_HEAD(pnfs_modules_tbl);
/* Return the registered pnfs layout driver module matching given id */
static struct pnfs_layoutdriver_type *
find_pnfs_driver_locked(u32 id)
{
struct pnfs_layoutdriver_type *local;
list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
if (local->id == id)
goto out;
local = NULL;
out:
dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
return local;
}
static struct pnfs_layoutdriver_type *
find_pnfs_driver(u32 id)
{
struct pnfs_layoutdriver_type *local;
spin_lock(&pnfs_spinlock);
local = find_pnfs_driver_locked(id);
spin_unlock(&pnfs_spinlock);
return local;
}
void
unset_pnfs_layoutdriver(struct nfs_server *nfss)
{
if (nfss->pnfs_curr_ld)
module_put(nfss->pnfs_curr_ld->owner);
nfss->pnfs_curr_ld = NULL;
}
/*
* Try to set the server's pnfs module to the pnfs layout type specified by id.
* Currently only one pNFS layout driver per filesystem is supported.
*
* @id layout type. Zero (illegal layout type) indicates pNFS not in use.
*/
void
set_pnfs_layoutdriver(struct nfs_server *server, u32 id)
{
struct pnfs_layoutdriver_type *ld_type = NULL;
if (id == 0)
goto out_no_driver;
if (!(server->nfs_client->cl_exchange_flags &
(EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__,
id, server->nfs_client->cl_exchange_flags);
goto out_no_driver;
}
ld_type = find_pnfs_driver(id);
if (!ld_type) {
request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
ld_type = find_pnfs_driver(id);
if (!ld_type) {
dprintk("%s: No pNFS module found for %u.\n",
__func__, id);
goto out_no_driver;
}
}
if (!try_module_get(ld_type->owner)) {
dprintk("%s: Could not grab reference on module\n", __func__);
goto out_no_driver;
}
server->pnfs_curr_ld = ld_type;
dprintk("%s: pNFS module for %u set\n", __func__, id);
return;
out_no_driver:
dprintk("%s: Using NFSv4 I/O\n", __func__);
server->pnfs_curr_ld = NULL;
}
int
pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
{
int status = -EINVAL;
struct pnfs_layoutdriver_type *tmp;
if (ld_type->id == 0) {
printk(KERN_ERR "%s id 0 is reserved\n", __func__);
return status;
}
if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
printk(KERN_ERR "%s Layout driver must provide "
"alloc_lseg and free_lseg.\n", __func__);
return status;
}
spin_lock(&pnfs_spinlock);
tmp = find_pnfs_driver_locked(ld_type->id);
if (!tmp) {
list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
status = 0;
dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
ld_type->name);
} else {
printk(KERN_ERR "%s Module with id %d already loaded!\n",
__func__, ld_type->id);
}
spin_unlock(&pnfs_spinlock);
return status;
}
EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
void
pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
{
dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
spin_lock(&pnfs_spinlock);
list_del(&ld_type->pnfs_tblid);
spin_unlock(&pnfs_spinlock);
}
EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
/*
* pNFS client layout cache
*/
/* Need to hold i_lock if caller does not already hold reference */
void
get_layout_hdr(struct pnfs_layout_hdr *lo)
{
atomic_inc(&lo->plh_refcount);
}
static void
destroy_layout_hdr(struct pnfs_layout_hdr *lo)
{
dprintk("%s: freeing layout cache %p\n", __func__, lo);
BUG_ON(!list_empty(&lo->plh_layouts));
NFS_I(lo->plh_inode)->layout = NULL;
kfree(lo);
}
static void
put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
{
if (atomic_dec_and_test(&lo->plh_refcount))
destroy_layout_hdr(lo);
}
void
put_layout_hdr(struct pnfs_layout_hdr *lo)
{
struct inode *inode = lo->plh_inode;
if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
destroy_layout_hdr(lo);
spin_unlock(&inode->i_lock);
}
}
static void
init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
{
INIT_LIST_HEAD(&lseg->pls_list);
atomic_set(&lseg->pls_refcount, 1);
smp_mb();
set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
lseg->pls_layout = lo;
}
static void free_lseg(struct pnfs_layout_segment *lseg)
{
struct inode *ino = lseg->pls_layout->plh_inode;
NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
/* Matched by get_layout_hdr in pnfs_insert_layout */
put_layout_hdr(NFS_I(ino)->layout);
}
static void
put_lseg_common(struct pnfs_layout_segment *lseg)
{
struct inode *inode = lseg->pls_layout->plh_inode;
BUG_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
list_del_init(&lseg->pls_list);
if (list_empty(&lseg->pls_layout->plh_segs)) {
set_bit(NFS_LAYOUT_DESTROYED, &lseg->pls_layout->plh_flags);
/* Matched by initial refcount set in alloc_init_layout_hdr */
put_layout_hdr_locked(lseg->pls_layout);
}
rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
}
void
put_lseg(struct pnfs_layout_segment *lseg)
{
struct inode *inode;
if (!lseg)
return;
dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
atomic_read(&lseg->pls_refcount),
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
inode = lseg->pls_layout->plh_inode;
if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
LIST_HEAD(free_me);
put_lseg_common(lseg);
list_add(&lseg->pls_list, &free_me);
spin_unlock(&inode->i_lock);
pnfs_free_lseg_list(&free_me);
}
}
EXPORT_SYMBOL_GPL(put_lseg);
static bool
should_free_lseg(u32 lseg_iomode, u32 recall_iomode)
{
return (recall_iomode == IOMODE_ANY ||
lseg_iomode == recall_iomode);
}
/* Returns 1 if lseg is removed from list, 0 otherwise */
static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
struct list_head *tmp_list)
{
int rv = 0;
if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
/* Remove the reference keeping the lseg in the
* list. It will now be removed when all
* outstanding io is finished.
*/
dprintk("%s: lseg %p ref %d\n", __func__, lseg,
atomic_read(&lseg->pls_refcount));
if (atomic_dec_and_test(&lseg->pls_refcount)) {
put_lseg_common(lseg);
list_add(&lseg->pls_list, tmp_list);
rv = 1;
}
}
return rv;
}
/* Returns count of number of matching invalid lsegs remaining in list
* after call.
*/
int
mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
struct list_head *tmp_list,
u32 iomode)
{
struct pnfs_layout_segment *lseg, *next;
int invalid = 0, removed = 0;
dprintk("%s:Begin lo %p\n", __func__, lo);
if (list_empty(&lo->plh_segs)) {
if (!test_and_set_bit(NFS_LAYOUT_DESTROYED, &lo->plh_flags))
put_layout_hdr_locked(lo);
return 0;
}
list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
if (should_free_lseg(lseg->pls_range.iomode, iomode)) {
dprintk("%s: freeing lseg %p iomode %d "
"offset %llu length %llu\n", __func__,
lseg, lseg->pls_range.iomode, lseg->pls_range.offset,
lseg->pls_range.length);
invalid++;
removed += mark_lseg_invalid(lseg, tmp_list);
}
dprintk("%s:Return %i\n", __func__, invalid - removed);
return invalid - removed;
}
/* note free_me must contain lsegs from a single layout_hdr */
void
pnfs_free_lseg_list(struct list_head *free_me)
{
struct pnfs_layout_segment *lseg, *tmp;
struct pnfs_layout_hdr *lo;
if (list_empty(free_me))
return;
lo = list_first_entry(free_me, struct pnfs_layout_segment,
pls_list)->pls_layout;
if (test_bit(NFS_LAYOUT_DESTROYED, &lo->plh_flags)) {
struct nfs_client *clp;
clp = NFS_SERVER(lo->plh_inode)->nfs_client;
spin_lock(&clp->cl_lock);
list_del_init(&lo->plh_layouts);
spin_unlock(&clp->cl_lock);
}
list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
list_del(&lseg->pls_list);
free_lseg(lseg);
}
}
void
pnfs_destroy_layout(struct nfs_inode *nfsi)
{
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
spin_lock(&nfsi->vfs_inode.i_lock);
lo = nfsi->layout;
if (lo) {
lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
mark_matching_lsegs_invalid(lo, &tmp_list, IOMODE_ANY);
}
spin_unlock(&nfsi->vfs_inode.i_lock);
pnfs_free_lseg_list(&tmp_list);
}
/*
* Called by the state manger to remove all layouts established under an
* expired lease.
*/
void
pnfs_destroy_all_layouts(struct nfs_client *clp)
{
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
spin_lock(&clp->cl_lock);
list_splice_init(&clp->cl_layouts, &tmp_list);
spin_unlock(&clp->cl_lock);
while (!list_empty(&tmp_list)) {
lo = list_entry(tmp_list.next, struct pnfs_layout_hdr,
plh_layouts);
dprintk("%s freeing layout for inode %lu\n", __func__,
lo->plh_inode->i_ino);
list_del_init(&lo->plh_layouts);
pnfs_destroy_layout(NFS_I(lo->plh_inode));
}
}
/* update lo->plh_stateid with new if is more recent */
void
pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
bool update_barrier)
{
u32 oldseq, newseq;
oldseq = be32_to_cpu(lo->plh_stateid.stateid.seqid);
newseq = be32_to_cpu(new->stateid.seqid);
if ((int)(newseq - oldseq) > 0) {
memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid));
if (update_barrier) {
u32 new_barrier = be32_to_cpu(new->stateid.seqid);
if ((int)(new_barrier - lo->plh_barrier))
lo->plh_barrier = new_barrier;
} else {
/* Because of wraparound, we want to keep the barrier
* "close" to the current seqids. It needs to be
* within 2**31 to count as "behind", so if it
* gets too near that limit, give us a litle leeway
* and bring it to within 2**30.
* NOTE - and yes, this is all unsigned arithmetic.
*/
if (unlikely((newseq - lo->plh_barrier) > (3 << 29)))
lo->plh_barrier = newseq - (1 << 30);
}
}
}
/* lget is set to 1 if called from inside send_layoutget call chain */
static bool
pnfs_layoutgets_blocked(struct pnfs_layout_hdr *lo, nfs4_stateid *stateid,
int lget)
{
if ((stateid) &&
(int)(lo->plh_barrier - be32_to_cpu(stateid->stateid.seqid)) >= 0)
return true;
return lo->plh_block_lgets ||
test_bit(NFS_LAYOUT_DESTROYED, &lo->plh_flags) ||
test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
(list_empty(&lo->plh_segs) &&
(atomic_read(&lo->plh_outstanding) > lget));
}
int
pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state)
{
int status = 0;
dprintk("--> %s\n", __func__);
spin_lock(&lo->plh_inode->i_lock);
if (pnfs_layoutgets_blocked(lo, NULL, 1)) {
status = -EAGAIN;
} else if (list_empty(&lo->plh_segs)) {
int seq;
do {
seq = read_seqbegin(&open_state->seqlock);
memcpy(dst->data, open_state->stateid.data,
sizeof(open_state->stateid.data));
} while (read_seqretry(&open_state->seqlock, seq));
} else
memcpy(dst->data, lo->plh_stateid.data, sizeof(lo->plh_stateid.data));
spin_unlock(&lo->plh_inode->i_lock);
dprintk("<-- %s\n", __func__);
return status;
}
/*
* Get layout from server.
* for now, assume that whole file layouts are requested.
* arg->offset: 0
* arg->length: all ones
*/
static struct pnfs_layout_segment *
send_layoutget(struct pnfs_layout_hdr *lo,
struct nfs_open_context *ctx,
u32 iomode,
gfp_t gfp_flags)
{
struct inode *ino = lo->plh_inode;
struct nfs_server *server = NFS_SERVER(ino);
struct nfs4_layoutget *lgp;
struct pnfs_layout_segment *lseg = NULL;
struct page **pages = NULL;
int i;
u32 max_resp_sz, max_pages;
dprintk("--> %s\n", __func__);
BUG_ON(ctx == NULL);
lgp = kzalloc(sizeof(*lgp), gfp_flags);
if (lgp == NULL)
return NULL;
/* allocate pages for xdr post processing */
max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
max_pages = max_resp_sz >> PAGE_SHIFT;
pages = kzalloc(max_pages * sizeof(struct page *), gfp_flags);
if (!pages)
goto out_err_free;
for (i = 0; i < max_pages; i++) {
pages[i] = alloc_page(gfp_flags);
if (!pages[i])
goto out_err_free;
}
lgp->args.minlength = NFS4_MAX_UINT64;
lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
lgp->args.range.iomode = iomode;
lgp->args.range.offset = 0;
lgp->args.range.length = NFS4_MAX_UINT64;
lgp->args.type = server->pnfs_curr_ld->id;
lgp->args.inode = ino;
lgp->args.ctx = get_nfs_open_context(ctx);
lgp->args.layout.pages = pages;
lgp->args.layout.pglen = max_pages * PAGE_SIZE;
lgp->lsegpp = &lseg;
lgp->gfp_flags = gfp_flags;
/* Synchronously retrieve layout information from server and
* store in lseg.
*/
nfs4_proc_layoutget(lgp);
if (!lseg) {
/* remember that LAYOUTGET failed and suspend trying */
set_bit(lo_fail_bit(iomode), &lo->plh_flags);
}
/* free xdr pages */
for (i = 0; i < max_pages; i++)
__free_page(pages[i]);
kfree(pages);
return lseg;
out_err_free:
/* free any allocated xdr pages, lgp as it's not used */
if (pages) {
for (i = 0; i < max_pages; i++) {
if (!pages[i])
break;
__free_page(pages[i]);
}
kfree(pages);
}
kfree(lgp);
return NULL;
}
bool pnfs_roc(struct inode *ino)
{
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg, *tmp;
LIST_HEAD(tmp_list);
bool found = false;
spin_lock(&ino->i_lock);
lo = NFS_I(ino)->layout;
if (!lo || !test_and_clear_bit(NFS_LAYOUT_ROC, &lo->plh_flags) ||
test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
goto out_nolayout;
list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
mark_lseg_invalid(lseg, &tmp_list);
found = true;
}
if (!found)
goto out_nolayout;
lo->plh_block_lgets++;
get_layout_hdr(lo); /* matched in pnfs_roc_release */
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&tmp_list);
return true;
out_nolayout:
spin_unlock(&ino->i_lock);
return false;
}
void pnfs_roc_release(struct inode *ino)
{
struct pnfs_layout_hdr *lo;
spin_lock(&ino->i_lock);
lo = NFS_I(ino)->layout;
lo->plh_block_lgets--;
put_layout_hdr_locked(lo);
spin_unlock(&ino->i_lock);
}
void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
{
struct pnfs_layout_hdr *lo;
spin_lock(&ino->i_lock);
lo = NFS_I(ino)->layout;
if ((int)(barrier - lo->plh_barrier) > 0)
lo->plh_barrier = barrier;
spin_unlock(&ino->i_lock);
}
bool pnfs_roc_drain(struct inode *ino, u32 *barrier)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_segment *lseg;
bool found = false;
spin_lock(&ino->i_lock);
list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list)
if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
found = true;
break;
}
if (!found) {
struct pnfs_layout_hdr *lo = nfsi->layout;
u32 current_seqid = be32_to_cpu(lo->plh_stateid.stateid.seqid);
/* Since close does not return a layout stateid for use as
* a barrier, we choose the worst-case barrier.
*/
*barrier = current_seqid + atomic_read(&lo->plh_outstanding);
}
spin_unlock(&ino->i_lock);
return found;
}
/*
* Compare two layout segments for sorting into layout cache.
* We want to preferentially return RW over RO layouts, so ensure those
* are seen first.
*/
static s64
cmp_layout(u32 iomode1, u32 iomode2)
{
/* read > read/write */
return (int)(iomode2 == IOMODE_READ) - (int)(iomode1 == IOMODE_READ);
}
static void
pnfs_insert_layout(struct pnfs_layout_hdr *lo,
struct pnfs_layout_segment *lseg)
{
struct pnfs_layout_segment *lp;
int found = 0;
dprintk("%s:Begin\n", __func__);
assert_spin_locked(&lo->plh_inode->i_lock);
list_for_each_entry(lp, &lo->plh_segs, pls_list) {
if (cmp_layout(lp->pls_range.iomode, lseg->pls_range.iomode) > 0)
continue;
list_add_tail(&lseg->pls_list, &lp->pls_list);
dprintk("%s: inserted lseg %p "
"iomode %d offset %llu length %llu before "
"lp %p iomode %d offset %llu length %llu\n",
__func__, lseg, lseg->pls_range.iomode,
lseg->pls_range.offset, lseg->pls_range.length,
lp, lp->pls_range.iomode, lp->pls_range.offset,
lp->pls_range.length);
found = 1;
break;
}
if (!found) {
list_add_tail(&lseg->pls_list, &lo->plh_segs);
dprintk("%s: inserted lseg %p "
"iomode %d offset %llu length %llu at tail\n",
__func__, lseg, lseg->pls_range.iomode,
lseg->pls_range.offset, lseg->pls_range.length);
}
get_layout_hdr(lo);
dprintk("%s:Return\n", __func__);
}
static struct pnfs_layout_hdr *
alloc_init_layout_hdr(struct inode *ino, gfp_t gfp_flags)
{
struct pnfs_layout_hdr *lo;
lo = kzalloc(sizeof(struct pnfs_layout_hdr), gfp_flags);
if (!lo)
return NULL;
atomic_set(&lo->plh_refcount, 1);
INIT_LIST_HEAD(&lo->plh_layouts);
INIT_LIST_HEAD(&lo->plh_segs);
INIT_LIST_HEAD(&lo->plh_bulk_recall);
lo->plh_inode = ino;
return lo;
}
static struct pnfs_layout_hdr *
pnfs_find_alloc_layout(struct inode *ino, gfp_t gfp_flags)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_hdr *new = NULL;
dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
assert_spin_locked(&ino->i_lock);
if (nfsi->layout) {
if (test_bit(NFS_LAYOUT_DESTROYED, &nfsi->layout->plh_flags))
return NULL;
else
return nfsi->layout;
}
spin_unlock(&ino->i_lock);
new = alloc_init_layout_hdr(ino, gfp_flags);
spin_lock(&ino->i_lock);
if (likely(nfsi->layout == NULL)) /* Won the race? */
nfsi->layout = new;
else
kfree(new);
return nfsi->layout;
}
/*
* iomode matching rules:
* iomode lseg match
* ----- ----- -----
* ANY READ true
* ANY RW true
* RW READ false
* RW RW true
* READ READ true
* READ RW true
*/
static int
is_matching_lseg(struct pnfs_layout_segment *lseg, u32 iomode)
{
return (iomode != IOMODE_RW || lseg->pls_range.iomode == IOMODE_RW);
}
/*
* lookup range in layout
*/
static struct pnfs_layout_segment *
pnfs_find_lseg(struct pnfs_layout_hdr *lo, u32 iomode)
{
struct pnfs_layout_segment *lseg, *ret = NULL;
dprintk("%s:Begin\n", __func__);
assert_spin_locked(&lo->plh_inode->i_lock);
list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
is_matching_lseg(lseg, iomode)) {
ret = get_lseg(lseg);
break;
}
if (cmp_layout(iomode, lseg->pls_range.iomode) > 0)
break;
}
dprintk("%s:Return lseg %p ref %d\n",
__func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
return ret;
}
/*
* Layout segment is retreived from the server if not cached.
* The appropriate layout segment is referenced and returned to the caller.
*/
struct pnfs_layout_segment *
pnfs_update_layout(struct inode *ino,
struct nfs_open_context *ctx,
enum pnfs_iomode iomode,
gfp_t gfp_flags)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct nfs_client *clp = NFS_SERVER(ino)->nfs_client;
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg = NULL;
bool first = false;
if (!pnfs_enabled_sb(NFS_SERVER(ino)))
return NULL;
spin_lock(&ino->i_lock);
lo = pnfs_find_alloc_layout(ino, gfp_flags);
if (lo == NULL) {
dprintk("%s ERROR: can't get pnfs_layout_hdr\n", __func__);
goto out_unlock;
}
/* Do we even need to bother with this? */
if (test_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state) ||
test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
dprintk("%s matches recall, use MDS\n", __func__);
goto out_unlock;
}
/* if LAYOUTGET already failed once we don't try again */
if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
goto out_unlock;
/* Check to see if the layout for the given range already exists */
lseg = pnfs_find_lseg(lo, iomode);
if (lseg)
goto out_unlock;
if (pnfs_layoutgets_blocked(lo, NULL, 0))
goto out_unlock;
atomic_inc(&lo->plh_outstanding);
get_layout_hdr(lo);
if (list_empty(&lo->plh_segs))
first = true;
spin_unlock(&ino->i_lock);
if (first) {
/* The lo must be on the clp list if there is any
* chance of a CB_LAYOUTRECALL(FILE) coming in.
*/
spin_lock(&clp->cl_lock);
BUG_ON(!list_empty(&lo->plh_layouts));
list_add_tail(&lo->plh_layouts, &clp->cl_layouts);
spin_unlock(&clp->cl_lock);
}
lseg = send_layoutget(lo, ctx, iomode, gfp_flags);
if (!lseg && first) {
spin_lock(&clp->cl_lock);
list_del_init(&lo->plh_layouts);
spin_unlock(&clp->cl_lock);
}
atomic_dec(&lo->plh_outstanding);
put_layout_hdr(lo);
out:
dprintk("%s end, state 0x%lx lseg %p\n", __func__,
nfsi->layout ? nfsi->layout->plh_flags : -1, lseg);
return lseg;
out_unlock:
spin_unlock(&ino->i_lock);
goto out;
}
int
pnfs_layout_process(struct nfs4_layoutget *lgp)
{
struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
struct nfs4_layoutget_res *res = &lgp->res;
struct pnfs_layout_segment *lseg;
struct inode *ino = lo->plh_inode;
struct nfs_client *clp = NFS_SERVER(ino)->nfs_client;
int status = 0;
/* Verify we got what we asked for.
* Note that because the xdr parsing only accepts a single
* element array, this can fail even if the server is behaving
* correctly.
*/
if (lgp->args.range.iomode > res->range.iomode ||
res->range.offset != 0 ||
res->range.length != NFS4_MAX_UINT64) {
status = -EINVAL;
goto out;
}
/* Inject layout blob into I/O device driver */
lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
if (!lseg || IS_ERR(lseg)) {
if (!lseg)
status = -ENOMEM;
else
status = PTR_ERR(lseg);
dprintk("%s: Could not allocate layout: error %d\n",
__func__, status);
goto out;
}
spin_lock(&ino->i_lock);
if (test_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state) ||
test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
dprintk("%s forget reply due to recall\n", __func__);
goto out_forget_reply;
}
if (pnfs_layoutgets_blocked(lo, &res->stateid, 1)) {
dprintk("%s forget reply due to state\n", __func__);
goto out_forget_reply;
}
init_lseg(lo, lseg);
lseg->pls_range = res->range;
*lgp->lsegpp = get_lseg(lseg);
pnfs_insert_layout(lo, lseg);
if (res->return_on_close) {
set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
set_bit(NFS_LAYOUT_ROC, &lo->plh_flags);
}
/* Done processing layoutget. Set the layout stateid */
pnfs_set_layout_stateid(lo, &res->stateid, false);
spin_unlock(&ino->i_lock);
out:
return status;
out_forget_reply:
spin_unlock(&ino->i_lock);
lseg->pls_layout = lo;
NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
goto out;
}
static int pnfs_read_pg_test(struct nfs_pageio_descriptor *pgio,
struct nfs_page *prev,
struct nfs_page *req)
{
if (pgio->pg_count == prev->wb_bytes) {
/* This is first coelesce call for a series of nfs_pages */
pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
prev->wb_context,
IOMODE_READ,
GFP_KERNEL);
}
return NFS_SERVER(pgio->pg_inode)->pnfs_curr_ld->pg_test(pgio, prev, req);
}
void
pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode)
{
struct pnfs_layoutdriver_type *ld;
ld = NFS_SERVER(inode)->pnfs_curr_ld;
pgio->pg_test = (ld && ld->pg_test) ? pnfs_read_pg_test : NULL;
}
static int pnfs_write_pg_test(struct nfs_pageio_descriptor *pgio,
struct nfs_page *prev,
struct nfs_page *req)
{
if (pgio->pg_count == prev->wb_bytes) {
/* This is first coelesce call for a series of nfs_pages */
pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
prev->wb_context,
IOMODE_RW,
GFP_NOFS);
}
return NFS_SERVER(pgio->pg_inode)->pnfs_curr_ld->pg_test(pgio, prev, req);
}
void
pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode)
{
struct pnfs_layoutdriver_type *ld;
ld = NFS_SERVER(inode)->pnfs_curr_ld;
pgio->pg_test = (ld && ld->pg_test) ? pnfs_write_pg_test : NULL;
}
enum pnfs_try_status
pnfs_try_to_write_data(struct nfs_write_data *wdata,
const struct rpc_call_ops *call_ops, int how)
{
struct inode *inode = wdata->inode;
enum pnfs_try_status trypnfs;
struct nfs_server *nfss = NFS_SERVER(inode);
wdata->mds_ops = call_ops;
dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
inode->i_ino, wdata->args.count, wdata->args.offset, how);
trypnfs = nfss->pnfs_curr_ld->write_pagelist(wdata, how);
if (trypnfs == PNFS_NOT_ATTEMPTED) {
put_lseg(wdata->lseg);
wdata->lseg = NULL;
} else
nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
return trypnfs;
}
/*
* Call the appropriate parallel I/O subsystem read function.
*/
enum pnfs_try_status
pnfs_try_to_read_data(struct nfs_read_data *rdata,
const struct rpc_call_ops *call_ops)
{
struct inode *inode = rdata->inode;
struct nfs_server *nfss = NFS_SERVER(inode);
enum pnfs_try_status trypnfs;
rdata->mds_ops = call_ops;
dprintk("%s: Reading ino:%lu %u@%llu\n",
__func__, inode->i_ino, rdata->args.count, rdata->args.offset);
trypnfs = nfss->pnfs_curr_ld->read_pagelist(rdata);
if (trypnfs == PNFS_NOT_ATTEMPTED) {
put_lseg(rdata->lseg);
rdata->lseg = NULL;
} else {
nfs_inc_stats(inode, NFSIOS_PNFS_READ);
}
dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
return trypnfs;
}
/*
* Currently there is only one (whole file) write lseg.
*/
static struct pnfs_layout_segment *pnfs_list_write_lseg(struct inode *inode)
{
struct pnfs_layout_segment *lseg, *rv = NULL;