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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 <linux/nfs_page.h>
#include <linux/module.h>
#include "internal.h"
#include "pnfs.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_PNFS
#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
/* 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);
if (local != NULL && !try_module_get(local->owner)) {
dprintk("%s: Could not grab reference on module\n", __func__);
local = NULL;
}
spin_unlock(&pnfs_spinlock);
return local;
}
void
unset_pnfs_layoutdriver(struct nfs_server *nfss)
{
if (nfss->pnfs_curr_ld) {
if (nfss->pnfs_curr_ld->clear_layoutdriver)
nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
/* Decrement the MDS count. Purge the deviceid cache if zero */
if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
nfs4_deviceid_purge_client(nfss->nfs_client);
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, const struct nfs_fh *mntfh,
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 "NFS: %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;
}
}
server->pnfs_curr_ld = ld_type;
if (ld_type->set_layoutdriver
&& ld_type->set_layoutdriver(server, mntfh)) {
printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
"driver %u.\n", __func__, id);
module_put(ld_type->owner);
goto out_no_driver;
}
/* Bump the MDS count */
atomic_inc(&server->nfs_client->cl_mds_count);
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 "NFS: %s id 0 is reserved\n", __func__);
return status;
}
if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
printk(KERN_ERR "NFS: %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 "NFS: %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
pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
{
atomic_inc(&lo->plh_refcount);
}
static struct pnfs_layout_hdr *
pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
{
struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
return ld->alloc_layout_hdr(ino, gfp_flags);
}
static void
pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
{
struct nfs_server *server = NFS_SERVER(lo->plh_inode);
struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
if (!list_empty(&lo->plh_layouts)) {
struct nfs_client *clp = server->nfs_client;
spin_lock(&clp->cl_lock);
list_del_init(&lo->plh_layouts);
spin_unlock(&clp->cl_lock);
}
put_rpccred(lo->plh_lc_cred);
return ld->free_layout_hdr(lo);
}
static void
pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
{
struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
dprintk("%s: freeing layout cache %p\n", __func__, lo);
nfsi->layout = NULL;
/* Reset MDS Threshold I/O counters */
nfsi->write_io = 0;
nfsi->read_io = 0;
}
void
pnfs_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)) {
pnfs_detach_layout_hdr(lo);
spin_unlock(&inode->i_lock);
pnfs_free_layout_hdr(lo);
}
}
static int
pnfs_iomode_to_fail_bit(u32 iomode)
{
return iomode == IOMODE_RW ?
NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
}
static void
pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
{
lo->plh_retry_timestamp = jiffies;
if (!test_and_set_bit(fail_bit, &lo->plh_flags))
atomic_inc(&lo->plh_refcount);
}
static void
pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
{
if (test_and_clear_bit(fail_bit, &lo->plh_flags))
atomic_dec(&lo->plh_refcount);
}
static void
pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
{
struct inode *inode = lo->plh_inode;
struct pnfs_layout_range range = {
.iomode = iomode,
.offset = 0,
.length = NFS4_MAX_UINT64,
};
LIST_HEAD(head);
spin_lock(&inode->i_lock);
pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
pnfs_mark_matching_lsegs_invalid(lo, &head, &range);
spin_unlock(&inode->i_lock);
pnfs_free_lseg_list(&head);
dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
iomode == IOMODE_RW ? "RW" : "READ");
}
static bool
pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
{
unsigned long start, end;
int fail_bit = pnfs_iomode_to_fail_bit(iomode);
if (test_bit(fail_bit, &lo->plh_flags) == 0)
return false;
end = jiffies;
start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
/* It is time to retry the failed layoutgets */
pnfs_layout_clear_fail_bit(lo, fail_bit);
return false;
}
return true;
}
static void
init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
{
INIT_LIST_HEAD(&lseg->pls_list);
INIT_LIST_HEAD(&lseg->pls_lc_list);
atomic_set(&lseg->pls_refcount, 1);
smp_mb();
set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
lseg->pls_layout = lo;
}
static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
{
struct inode *ino = lseg->pls_layout->plh_inode;
NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
}
static void
pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
struct pnfs_layout_segment *lseg)
{
struct inode *inode = lo->plh_inode;
WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
list_del_init(&lseg->pls_list);
/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
atomic_dec(&lo->plh_refcount);
if (list_empty(&lo->plh_segs))
clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
}
void
pnfs_put_lseg(struct pnfs_layout_segment *lseg)
{
struct pnfs_layout_hdr *lo;
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));
lo = lseg->pls_layout;
inode = lo->plh_inode;
if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
pnfs_get_layout_hdr(lo);
pnfs_layout_remove_lseg(lo, lseg);
spin_unlock(&inode->i_lock);
pnfs_free_lseg(lseg);
pnfs_put_layout_hdr(lo);
}
}
EXPORT_SYMBOL_GPL(pnfs_put_lseg);
static inline u64
end_offset(u64 start, u64 len)
{
u64 end;
end = start + len;
return end >= start ? end : NFS4_MAX_UINT64;
}
/*
* is l2 fully contained in l1?
* start1 end1
* [----------------------------------)
* start2 end2
* [----------------)
*/
static inline int
lo_seg_contained(struct pnfs_layout_range *l1,
struct pnfs_layout_range *l2)
{
u64 start1 = l1->offset;
u64 end1 = end_offset(start1, l1->length);
u64 start2 = l2->offset;
u64 end2 = end_offset(start2, l2->length);
return (start1 <= start2) && (end1 >= end2);
}
/*
* is l1 and l2 intersecting?
* start1 end1
* [----------------------------------)
* start2 end2
* [----------------)
*/
static inline int
lo_seg_intersecting(struct pnfs_layout_range *l1,
struct pnfs_layout_range *l2)
{
u64 start1 = l1->offset;
u64 end1 = end_offset(start1, l1->length);
u64 start2 = l2->offset;
u64 end2 = end_offset(start2, l2->length);
return (end1 == NFS4_MAX_UINT64 || end1 > start2) &&
(end2 == NFS4_MAX_UINT64 || end2 > start1);
}
static bool
should_free_lseg(struct pnfs_layout_range *lseg_range,
struct pnfs_layout_range *recall_range)
{
return (recall_range->iomode == IOMODE_ANY ||
lseg_range->iomode == recall_range->iomode) &&
lo_seg_intersecting(lseg_range, recall_range);
}
/* 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)) {
pnfs_layout_remove_lseg(lseg->pls_layout, 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
pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
struct list_head *tmp_list,
struct pnfs_layout_range *recall_range)
{
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))
return 0;
list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
if (!recall_range ||
should_free_lseg(&lseg->pls_range, recall_range)) {
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;
if (list_empty(free_me))
return;
list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
list_del(&lseg->pls_list);
pnfs_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 */
pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
pnfs_get_layout_hdr(lo);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
spin_unlock(&nfsi->vfs_inode.i_lock);
pnfs_free_lseg_list(&tmp_list);
pnfs_put_layout_hdr(lo);
} else
spin_unlock(&nfsi->vfs_inode.i_lock);
}
EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
/*
* Called by the state manger to remove all layouts established under an
* expired lease.
*/
void
pnfs_destroy_all_layouts(struct nfs_client *clp)
{
struct nfs_server *server;
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
nfs4_deviceid_mark_client_invalid(clp);
nfs4_deviceid_purge_client(clp);
spin_lock(&clp->cl_lock);
rcu_read_lock();
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
if (!list_empty(&server->layouts))
list_splice_init(&server->layouts, &tmp_list);
}
rcu_read_unlock();
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));
}
}
/*
* Compare 2 layout stateid sequence ids, to see which is newer,
* taking into account wraparound issues.
*/
static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
{
return (s32)s1 - (s32)s2 > 0;
}
/* 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, new_barrier;
int empty = list_empty(&lo->plh_segs);
oldseq = be32_to_cpu(lo->plh_stateid.seqid);
newseq = be32_to_cpu(new->seqid);
if (empty || pnfs_seqid_is_newer(newseq, oldseq)) {
nfs4_stateid_copy(&lo->plh_stateid, new);
if (update_barrier) {
new_barrier = be32_to_cpu(new->seqid);
} else {
/* Because of wraparound, we want to keep the barrier
* "close" to the current seqids.
*/
new_barrier = newseq - atomic_read(&lo->plh_outstanding);
}
if (empty || pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
lo->plh_barrier = new_barrier;
}
}
static bool
pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
const nfs4_stateid *stateid)
{
u32 seqid = be32_to_cpu(stateid->seqid);
return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
}
/* lget is set to 1 if called from inside send_layoutget call chain */
static bool
pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo, int lget)
{
return lo->plh_block_lgets ||
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, 1)) {
status = -EAGAIN;
} else if (list_empty(&lo->plh_segs)) {
int seq;
do {
seq = read_seqbegin(&open_state->seqlock);
nfs4_stateid_copy(dst, &open_state->stateid);
} while (read_seqretry(&open_state->seqlock, seq));
} else
nfs4_stateid_copy(dst, &lo->plh_stateid);
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,
struct pnfs_layout_range *range,
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;
dprintk("--> %s\n", __func__);
lgp = kzalloc(sizeof(*lgp), gfp_flags);
if (lgp == NULL)
return NULL;
lgp->args.minlength = PAGE_CACHE_SIZE;
if (lgp->args.minlength > range->length)
lgp->args.minlength = range->length;
lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
lgp->args.range = *range;
lgp->args.type = server->pnfs_curr_ld->id;
lgp->args.inode = ino;
lgp->args.ctx = get_nfs_open_context(ctx);
lgp->gfp_flags = gfp_flags;
/* Synchronously retrieve layout information from server and
* store in lseg.
*/
lseg = nfs4_proc_layoutget(lgp, gfp_flags);
if (IS_ERR(lseg)) {
switch (PTR_ERR(lseg)) {
case -ENOMEM:
case -ERESTARTSYS:
break;
default:
/* remember that LAYOUTGET failed and suspend trying */
pnfs_layout_io_set_failed(lo, range->iomode);
}
return NULL;
}
return lseg;
}
/*
* Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
* when the layout segment list is empty.
*
* Note that a pnfs_layout_hdr can exist with an empty layout segment
* list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
* deviceid is marked invalid.
*/
int
_pnfs_return_layout(struct inode *ino)
{
struct pnfs_layout_hdr *lo = NULL;
struct nfs_inode *nfsi = NFS_I(ino);
LIST_HEAD(tmp_list);
struct nfs4_layoutreturn *lrp;
nfs4_stateid stateid;
int status = 0, empty;
dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
spin_lock(&ino->i_lock);
lo = nfsi->layout;
if (!lo) {
spin_unlock(&ino->i_lock);
dprintk("NFS: %s no layout to return\n", __func__);
goto out;
}
stateid = nfsi->layout->plh_stateid;
/* Reference matched in nfs4_layoutreturn_release */
pnfs_get_layout_hdr(lo);
empty = list_empty(&lo->plh_segs);
pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
/* Don't send a LAYOUTRETURN if list was initially empty */
if (empty) {
spin_unlock(&ino->i_lock);
pnfs_put_layout_hdr(lo);
dprintk("NFS: %s no layout segments to return\n", __func__);
goto out;
}
lo->plh_block_lgets++;
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&tmp_list);
WARN_ON(test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags));
lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
if (unlikely(lrp == NULL)) {
status = -ENOMEM;
spin_lock(&ino->i_lock);
lo->plh_block_lgets--;
spin_unlock(&ino->i_lock);
pnfs_put_layout_hdr(lo);
goto out;
}
lrp->args.stateid = stateid;
lrp->args.layout_type = NFS_SERVER(ino)->pnfs_curr_ld->id;
lrp->args.inode = ino;
lrp->args.layout = lo;
lrp->clp = NFS_SERVER(ino)->nfs_client;
status = nfs4_proc_layoutreturn(lrp);
out:
dprintk("<-- %s status: %d\n", __func__, status);
return status;
}
EXPORT_SYMBOL_GPL(_pnfs_return_layout);
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++;
pnfs_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--;
if (atomic_dec_and_test(&lo->plh_refcount)) {
pnfs_detach_layout_hdr(lo);
spin_unlock(&ino->i_lock);
pnfs_free_layout_hdr(lo);
} else
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 (pnfs_seqid_is_newer(barrier, lo->plh_barrier))
lo->plh_barrier = barrier;
spin_unlock(&ino->i_lock);
}
bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg;
u32 current_seqid;
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)) {
rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
found = true;
goto out;
}
lo = nfsi->layout;
current_seqid = be32_to_cpu(lo->plh_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);
out:
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(struct pnfs_layout_range *l1,
struct pnfs_layout_range *l2)
{
s64 d;
/* high offset > low offset */
d = l1->offset - l2->offset;
if (d)
return d;
/* short length > long length */
d = l2->length - l1->length;
if (d)
return d;
/* read > read/write */
return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
}
static void
pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
struct pnfs_layout_segment *lseg)
{
struct pnfs_layout_segment *lp;
dprintk("%s:Begin\n", __func__);
list_for_each_entry(lp, &lo->plh_segs, pls_list) {
if (cmp_layout(&lseg->pls_range, &lp->pls_range) > 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);
goto out;
}
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);
out:
pnfs_get_layout_hdr(lo);
dprintk("%s:Return\n", __func__);
}
static struct pnfs_layout_hdr *
alloc_init_layout_hdr(struct inode *ino,
struct nfs_open_context *ctx,
gfp_t gfp_flags)
{
struct pnfs_layout_hdr *lo;
lo = pnfs_alloc_layout_hdr(ino, 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;
lo->plh_lc_cred = get_rpccred(ctx->state->owner->so_cred);
return lo;
}
static struct pnfs_layout_hdr *
pnfs_find_alloc_layout(struct inode *ino,
struct nfs_open_context *ctx,
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);
if (nfsi->layout != NULL)
goto out_existing;
spin_unlock(&ino->i_lock);
new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
spin_lock(&ino->i_lock);
if (likely(nfsi->layout == NULL)) { /* Won the race? */
nfsi->layout = new;
return new;
} else if (new != NULL)
pnfs_free_layout_hdr(new);
out_existing:
pnfs_get_layout_hdr(nfsi->layout);
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_range *ls_range,
struct pnfs_layout_range *range)
{
struct pnfs_layout_range range1;
if ((range->iomode == IOMODE_RW &&
ls_range->iomode != IOMODE_RW) ||
!lo_seg_intersecting(ls_range, range))
return 0;
/* range1 covers only the first byte in the range */
range1 = *range;
range1.length = 1;
return lo_seg_contained(ls_range, &range1);
}
/*
* lookup range in layout
*/
static struct pnfs_layout_segment *
pnfs_find_lseg(struct pnfs_layout_hdr *lo,
struct pnfs_layout_range *range)
{
struct pnfs_layout_segment *lseg, *ret = NULL;
dprintk("%s:Begin\n", __func__);
list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
is_matching_lseg(&lseg->pls_range, range)) {
ret = pnfs_get_lseg(lseg);
break;
}
if (lseg->pls_range.offset > range->offset)
break;
}
dprintk("%s:Return lseg %p ref %d\n",
__func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
return ret;
}
/*
* Use mdsthreshold hints set at each OPEN to determine if I/O should go
* to the MDS or over pNFS
*
* The nfs_inode read_io and write_io fields are cumulative counters reset
* when there are no layout segments. Note that in pnfs_update_layout iomode
* is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
* WRITE request.
*
* A return of true means use MDS I/O.
*
* From rfc 5661:
* If a file's size is smaller than the file size threshold, data accesses
* SHOULD be sent to the metadata server. If an I/O request has a length that
* is below the I/O size threshold, the I/O SHOULD be sent to the metadata
* server. If both file size and I/O size are provided, the client SHOULD
* reach or exceed both thresholds before sending its read or write
* requests to the data server.
*/
static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
struct inode *ino, int iomode)
{
struct nfs4_threshold *t = ctx->mdsthreshold;
struct nfs_inode *nfsi = NFS_I(ino);