linux/fs/nfs/nfs4filelayout.c
Trond Myklebust 1751c3638f NFS: Cleanup of the nfs_pageio code in preparation for a pnfs bugfix
We need to ensure that the layouts are set up before we can decide to
coalesce requests. To do so, we want to further split up the struct
nfs_pageio_descriptor operations into an initialisation callback, a
coalescing test callback, and a 'do i/o' callback.

This patch cleans up the existing callback methods before adding the
'initialisation' callback.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12 13:40:28 -04:00

916 lines
25 KiB
C

/*
* Module for the pnfs nfs4 file layout driver.
* Defines all I/O and Policy interface operations, plus code
* to register itself with the pNFS client.
*
* Copyright (c) 2002
* The Regents of the University of Michigan
* All Rights Reserved
*
* Dean Hildebrand <dhildebz@umich.edu>
*
* 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 "internal.h"
#include "nfs4filelayout.h"
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
MODULE_DESCRIPTION("The NFSv4 file layout driver");
#define FILELAYOUT_POLL_RETRY_MAX (15*HZ)
static loff_t
filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
loff_t offset)
{
u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
u64 tmp;
offset -= flseg->pattern_offset;
tmp = offset;
do_div(tmp, stripe_width);
return tmp * flseg->stripe_unit + do_div(offset, flseg->stripe_unit);
}
/* This function is used by the layout driver to calculate the
* offset of the file on the dserver based on whether the
* layout type is STRIPE_DENSE or STRIPE_SPARSE
*/
static loff_t
filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
{
struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
switch (flseg->stripe_type) {
case STRIPE_SPARSE:
return offset;
case STRIPE_DENSE:
return filelayout_get_dense_offset(flseg, offset);
}
BUG();
}
/* For data server errors we don't recover from */
static void
filelayout_set_lo_fail(struct pnfs_layout_segment *lseg)
{
if (lseg->pls_range.iomode == IOMODE_RW) {
dprintk("%s Setting layout IOMODE_RW fail bit\n", __func__);
set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
} else {
dprintk("%s Setting layout IOMODE_READ fail bit\n", __func__);
set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
}
}
static int filelayout_async_handle_error(struct rpc_task *task,
struct nfs4_state *state,
struct nfs_client *clp,
int *reset)
{
if (task->tk_status >= 0)
return 0;
*reset = 0;
switch (task->tk_status) {
case -NFS4ERR_BADSESSION:
case -NFS4ERR_BADSLOT:
case -NFS4ERR_BAD_HIGH_SLOT:
case -NFS4ERR_DEADSESSION:
case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
case -NFS4ERR_SEQ_FALSE_RETRY:
case -NFS4ERR_SEQ_MISORDERED:
dprintk("%s ERROR %d, Reset session. Exchangeid "
"flags 0x%x\n", __func__, task->tk_status,
clp->cl_exchange_flags);
nfs4_schedule_session_recovery(clp->cl_session);
break;
case -NFS4ERR_DELAY:
case -NFS4ERR_GRACE:
case -EKEYEXPIRED:
rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
break;
case -NFS4ERR_RETRY_UNCACHED_REP:
break;
default:
dprintk("%s DS error. Retry through MDS %d\n", __func__,
task->tk_status);
*reset = 1;
break;
}
task->tk_status = 0;
return -EAGAIN;
}
/* NFS_PROTO call done callback routines */
static int filelayout_read_done_cb(struct rpc_task *task,
struct nfs_read_data *data)
{
struct nfs_client *clp = data->ds_clp;
int reset = 0;
dprintk("%s DS read\n", __func__);
if (filelayout_async_handle_error(task, data->args.context->state,
data->ds_clp, &reset) == -EAGAIN) {
dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
__func__, data->ds_clp, data->ds_clp->cl_session);
if (reset) {
filelayout_set_lo_fail(data->lseg);
nfs4_reset_read(task, data);
clp = NFS_SERVER(data->inode)->nfs_client;
}
nfs_restart_rpc(task, clp);
return -EAGAIN;
}
return 0;
}
/*
* We reference the rpc_cred of the first WRITE that triggers the need for
* a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
* rfc5661 is not clear about which credential should be used.
*/
static void
filelayout_set_layoutcommit(struct nfs_write_data *wdata)
{
if (FILELAYOUT_LSEG(wdata->lseg)->commit_through_mds ||
wdata->res.verf->committed == NFS_FILE_SYNC)
return;
pnfs_set_layoutcommit(wdata);
dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, wdata->inode->i_ino,
(unsigned long) wdata->lseg->pls_end_pos);
}
/*
* Call ops for the async read/write cases
* In the case of dense layouts, the offset needs to be reset to its
* original value.
*/
static void filelayout_read_prepare(struct rpc_task *task, void *data)
{
struct nfs_read_data *rdata = (struct nfs_read_data *)data;
rdata->read_done_cb = filelayout_read_done_cb;
if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
&rdata->args.seq_args, &rdata->res.seq_res,
0, task))
return;
rpc_call_start(task);
}
static void filelayout_read_call_done(struct rpc_task *task, void *data)
{
struct nfs_read_data *rdata = (struct nfs_read_data *)data;
dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
/* Note this may cause RPC to be resent */
rdata->mds_ops->rpc_call_done(task, data);
}
static void filelayout_read_release(void *data)
{
struct nfs_read_data *rdata = (struct nfs_read_data *)data;
rdata->mds_ops->rpc_release(data);
}
static int filelayout_write_done_cb(struct rpc_task *task,
struct nfs_write_data *data)
{
int reset = 0;
if (filelayout_async_handle_error(task, data->args.context->state,
data->ds_clp, &reset) == -EAGAIN) {
struct nfs_client *clp;
dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
__func__, data->ds_clp, data->ds_clp->cl_session);
if (reset) {
filelayout_set_lo_fail(data->lseg);
nfs4_reset_write(task, data);
clp = NFS_SERVER(data->inode)->nfs_client;
} else
clp = data->ds_clp;
nfs_restart_rpc(task, clp);
return -EAGAIN;
}
filelayout_set_layoutcommit(data);
return 0;
}
/* Fake up some data that will cause nfs_commit_release to retry the writes. */
static void prepare_to_resend_writes(struct nfs_write_data *data)
{
struct nfs_page *first = nfs_list_entry(data->pages.next);
data->task.tk_status = 0;
memcpy(data->verf.verifier, first->wb_verf.verifier,
sizeof(first->wb_verf.verifier));
data->verf.verifier[0]++; /* ensure verifier mismatch */
}
static int filelayout_commit_done_cb(struct rpc_task *task,
struct nfs_write_data *data)
{
int reset = 0;
if (filelayout_async_handle_error(task, data->args.context->state,
data->ds_clp, &reset) == -EAGAIN) {
dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
__func__, data->ds_clp, data->ds_clp->cl_session);
if (reset) {
prepare_to_resend_writes(data);
filelayout_set_lo_fail(data->lseg);
} else
nfs_restart_rpc(task, data->ds_clp);
return -EAGAIN;
}
return 0;
}
static void filelayout_write_prepare(struct rpc_task *task, void *data)
{
struct nfs_write_data *wdata = (struct nfs_write_data *)data;
if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
&wdata->args.seq_args, &wdata->res.seq_res,
0, task))
return;
rpc_call_start(task);
}
static void filelayout_write_call_done(struct rpc_task *task, void *data)
{
struct nfs_write_data *wdata = (struct nfs_write_data *)data;
/* Note this may cause RPC to be resent */
wdata->mds_ops->rpc_call_done(task, data);
}
static void filelayout_write_release(void *data)
{
struct nfs_write_data *wdata = (struct nfs_write_data *)data;
wdata->mds_ops->rpc_release(data);
}
static void filelayout_commit_release(void *data)
{
struct nfs_write_data *wdata = (struct nfs_write_data *)data;
nfs_commit_release_pages(wdata);
if (atomic_dec_and_test(&NFS_I(wdata->inode)->commits_outstanding))
nfs_commit_clear_lock(NFS_I(wdata->inode));
nfs_commitdata_release(wdata);
}
struct rpc_call_ops filelayout_read_call_ops = {
.rpc_call_prepare = filelayout_read_prepare,
.rpc_call_done = filelayout_read_call_done,
.rpc_release = filelayout_read_release,
};
struct rpc_call_ops filelayout_write_call_ops = {
.rpc_call_prepare = filelayout_write_prepare,
.rpc_call_done = filelayout_write_call_done,
.rpc_release = filelayout_write_release,
};
struct rpc_call_ops filelayout_commit_call_ops = {
.rpc_call_prepare = filelayout_write_prepare,
.rpc_call_done = filelayout_write_call_done,
.rpc_release = filelayout_commit_release,
};
static enum pnfs_try_status
filelayout_read_pagelist(struct nfs_read_data *data)
{
struct pnfs_layout_segment *lseg = data->lseg;
struct nfs4_pnfs_ds *ds;
loff_t offset = data->args.offset;
u32 j, idx;
struct nfs_fh *fh;
int status;
dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
__func__, data->inode->i_ino,
data->args.pgbase, (size_t)data->args.count, offset);
/* Retrieve the correct rpc_client for the byte range */
j = nfs4_fl_calc_j_index(lseg, offset);
idx = nfs4_fl_calc_ds_index(lseg, j);
ds = nfs4_fl_prepare_ds(lseg, idx);
if (!ds) {
/* Either layout fh index faulty, or ds connect failed */
set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
return PNFS_NOT_ATTEMPTED;
}
dprintk("%s USE DS: %s\n", __func__, ds->ds_remotestr);
/* No multipath support. Use first DS */
data->ds_clp = ds->ds_clp;
fh = nfs4_fl_select_ds_fh(lseg, j);
if (fh)
data->args.fh = fh;
data->args.offset = filelayout_get_dserver_offset(lseg, offset);
data->mds_offset = offset;
/* Perform an asynchronous read to ds */
status = nfs_initiate_read(data, ds->ds_clp->cl_rpcclient,
&filelayout_read_call_ops);
BUG_ON(status != 0);
return PNFS_ATTEMPTED;
}
/* Perform async writes. */
static enum pnfs_try_status
filelayout_write_pagelist(struct nfs_write_data *data, int sync)
{
struct pnfs_layout_segment *lseg = data->lseg;
struct nfs4_pnfs_ds *ds;
loff_t offset = data->args.offset;
u32 j, idx;
struct nfs_fh *fh;
int status;
/* Retrieve the correct rpc_client for the byte range */
j = nfs4_fl_calc_j_index(lseg, offset);
idx = nfs4_fl_calc_ds_index(lseg, j);
ds = nfs4_fl_prepare_ds(lseg, idx);
if (!ds) {
printk(KERN_ERR "%s: prepare_ds failed, use MDS\n", __func__);
set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
return PNFS_NOT_ATTEMPTED;
}
dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s\n", __func__,
data->inode->i_ino, sync, (size_t) data->args.count, offset,
ds->ds_remotestr);
data->write_done_cb = filelayout_write_done_cb;
data->ds_clp = ds->ds_clp;
fh = nfs4_fl_select_ds_fh(lseg, j);
if (fh)
data->args.fh = fh;
/*
* Get the file offset on the dserver. Set the write offset to
* this offset and save the original offset.
*/
data->args.offset = filelayout_get_dserver_offset(lseg, offset);
/* Perform an asynchronous write */
status = nfs_initiate_write(data, ds->ds_clp->cl_rpcclient,
&filelayout_write_call_ops, sync);
BUG_ON(status != 0);
return PNFS_ATTEMPTED;
}
/*
* filelayout_check_layout()
*
* Make sure layout segment parameters are sane WRT the device.
* At this point no generic layer initialization of the lseg has occurred,
* and nothing has been added to the layout_hdr cache.
*
*/
static int
filelayout_check_layout(struct pnfs_layout_hdr *lo,
struct nfs4_filelayout_segment *fl,
struct nfs4_layoutget_res *lgr,
struct nfs4_deviceid *id,
gfp_t gfp_flags)
{
struct nfs4_deviceid_node *d;
struct nfs4_file_layout_dsaddr *dsaddr;
int status = -EINVAL;
struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
dprintk("--> %s\n", __func__);
if (fl->pattern_offset > lgr->range.offset) {
dprintk("%s pattern_offset %lld too large\n",
__func__, fl->pattern_offset);
goto out;
}
if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
dprintk("%s Invalid stripe unit (%u)\n",
__func__, fl->stripe_unit);
goto out;
}
/* find and reference the deviceid */
d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
NFS_SERVER(lo->plh_inode)->nfs_client, id);
if (d == NULL) {
dsaddr = get_device_info(lo->plh_inode, id, gfp_flags);
if (dsaddr == NULL)
goto out;
} else
dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
fl->dsaddr = dsaddr;
if (fl->first_stripe_index < 0 ||
fl->first_stripe_index >= dsaddr->stripe_count) {
dprintk("%s Bad first_stripe_index %d\n",
__func__, fl->first_stripe_index);
goto out_put;
}
if ((fl->stripe_type == STRIPE_SPARSE &&
fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
(fl->stripe_type == STRIPE_DENSE &&
fl->num_fh != dsaddr->stripe_count)) {
dprintk("%s num_fh %u not valid for given packing\n",
__func__, fl->num_fh);
goto out_put;
}
if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
dprintk("%s Stripe unit (%u) not aligned with rsize %u "
"wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
nfss->wsize);
}
status = 0;
out:
dprintk("--> %s returns %d\n", __func__, status);
return status;
out_put:
nfs4_fl_put_deviceid(dsaddr);
goto out;
}
static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
{
int i;
for (i = 0; i < fl->num_fh; i++) {
if (!fl->fh_array[i])
break;
kfree(fl->fh_array[i]);
}
kfree(fl->fh_array);
fl->fh_array = NULL;
}
static void
_filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
{
filelayout_free_fh_array(fl);
kfree(fl);
}
static int
filelayout_decode_layout(struct pnfs_layout_hdr *flo,
struct nfs4_filelayout_segment *fl,
struct nfs4_layoutget_res *lgr,
struct nfs4_deviceid *id,
gfp_t gfp_flags)
{
struct xdr_stream stream;
struct xdr_buf buf;
struct page *scratch;
__be32 *p;
uint32_t nfl_util;
int i;
dprintk("%s: set_layout_map Begin\n", __func__);
scratch = alloc_page(gfp_flags);
if (!scratch)
return -ENOMEM;
xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
/* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
* num_fh (4) */
p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
if (unlikely(!p))
goto out_err;
memcpy(id, p, sizeof(*id));
p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
nfs4_print_deviceid(id);
nfl_util = be32_to_cpup(p++);
if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
fl->commit_through_mds = 1;
if (nfl_util & NFL4_UFLG_DENSE)
fl->stripe_type = STRIPE_DENSE;
else
fl->stripe_type = STRIPE_SPARSE;
fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
fl->first_stripe_index = be32_to_cpup(p++);
p = xdr_decode_hyper(p, &fl->pattern_offset);
fl->num_fh = be32_to_cpup(p++);
dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
__func__, nfl_util, fl->num_fh, fl->first_stripe_index,
fl->pattern_offset);
/* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
* Futher checking is done in filelayout_check_layout */
if (fl->num_fh < 0 || fl->num_fh >
max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
goto out_err;
if (fl->num_fh > 0) {
fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
gfp_flags);
if (!fl->fh_array)
goto out_err;
}
for (i = 0; i < fl->num_fh; i++) {
/* Do we want to use a mempool here? */
fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
if (!fl->fh_array[i])
goto out_err_free;
p = xdr_inline_decode(&stream, 4);
if (unlikely(!p))
goto out_err_free;
fl->fh_array[i]->size = be32_to_cpup(p++);
if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
printk(KERN_ERR "Too big fh %d received %d\n",
i, fl->fh_array[i]->size);
goto out_err_free;
}
p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
if (unlikely(!p))
goto out_err_free;
memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
dprintk("DEBUG: %s: fh len %d\n", __func__,
fl->fh_array[i]->size);
}
__free_page(scratch);
return 0;
out_err_free:
filelayout_free_fh_array(fl);
out_err:
__free_page(scratch);
return -EIO;
}
static void
filelayout_free_lseg(struct pnfs_layout_segment *lseg)
{
struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
dprintk("--> %s\n", __func__);
nfs4_fl_put_deviceid(fl->dsaddr);
kfree(fl->commit_buckets);
_filelayout_free_lseg(fl);
}
static struct pnfs_layout_segment *
filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
struct nfs4_layoutget_res *lgr,
gfp_t gfp_flags)
{
struct nfs4_filelayout_segment *fl;
int rc;
struct nfs4_deviceid id;
dprintk("--> %s\n", __func__);
fl = kzalloc(sizeof(*fl), gfp_flags);
if (!fl)
return NULL;
rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
_filelayout_free_lseg(fl);
return NULL;
}
/* This assumes there is only one IOMODE_RW lseg. What
* we really want to do is have a layout_hdr level
* dictionary of <multipath_list4, fh> keys, each
* associated with a struct list_head, populated by calls
* to filelayout_write_pagelist().
* */
if ((!fl->commit_through_mds) && (lgr->range.iomode == IOMODE_RW)) {
int i;
int size = (fl->stripe_type == STRIPE_SPARSE) ?
fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
fl->commit_buckets = kcalloc(size, sizeof(struct list_head), gfp_flags);
if (!fl->commit_buckets) {
filelayout_free_lseg(&fl->generic_hdr);
return NULL;
}
fl->number_of_buckets = size;
for (i = 0; i < size; i++)
INIT_LIST_HEAD(&fl->commit_buckets[i]);
}
return &fl->generic_hdr;
}
/*
* filelayout_pg_test(). Called by nfs_can_coalesce_requests()
*
* return true : coalesce page
* return false : don't coalesce page
*/
static bool
filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
struct nfs_page *req)
{
u64 p_stripe, r_stripe;
u32 stripe_unit;
if (!pnfs_generic_pg_test(pgio, prev, req) ||
!nfs_generic_pg_test(pgio, prev, req))
return false;
if (!pgio->pg_lseg)
return 1;
p_stripe = (u64)prev->wb_index << PAGE_CACHE_SHIFT;
r_stripe = (u64)req->wb_index << PAGE_CACHE_SHIFT;
stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
do_div(p_stripe, stripe_unit);
do_div(r_stripe, stripe_unit);
return (p_stripe == r_stripe);
}
static const struct nfs_pageio_ops filelayout_pg_read_ops = {
.pg_test = filelayout_pg_test,
.pg_doio = nfs_generic_pg_readpages,
};
static const struct nfs_pageio_ops filelayout_pg_write_ops = {
.pg_test = filelayout_pg_test,
.pg_doio = nfs_generic_pg_writepages,
};
static bool filelayout_mark_pnfs_commit(struct pnfs_layout_segment *lseg)
{
return !FILELAYOUT_LSEG(lseg)->commit_through_mds;
}
static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
{
if (fl->stripe_type == STRIPE_SPARSE)
return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
else
return j;
}
struct list_head *filelayout_choose_commit_list(struct nfs_page *req)
{
struct pnfs_layout_segment *lseg = req->wb_commit_lseg;
struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
u32 i, j;
struct list_head *list;
/* Note that we are calling nfs4_fl_calc_j_index on each page
* that ends up being committed to a data server. An attractive
* alternative is to add a field to nfs_write_data and nfs_page
* to store the value calculated in filelayout_write_pagelist
* and just use that here.
*/
j = nfs4_fl_calc_j_index(lseg,
(loff_t)req->wb_index << PAGE_CACHE_SHIFT);
i = select_bucket_index(fl, j);
list = &fl->commit_buckets[i];
if (list_empty(list)) {
/* Non-empty buckets hold a reference on the lseg */
get_lseg(lseg);
}
return list;
}
static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
{
struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
if (flseg->stripe_type == STRIPE_SPARSE)
return i;
else
return nfs4_fl_calc_ds_index(lseg, i);
}
static struct nfs_fh *
select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
{
struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
if (flseg->stripe_type == STRIPE_SPARSE) {
if (flseg->num_fh == 1)
i = 0;
else if (flseg->num_fh == 0)
/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
return NULL;
}
return flseg->fh_array[i];
}
static int filelayout_initiate_commit(struct nfs_write_data *data, int how)
{
struct pnfs_layout_segment *lseg = data->lseg;
struct nfs4_pnfs_ds *ds;
u32 idx;
struct nfs_fh *fh;
idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
ds = nfs4_fl_prepare_ds(lseg, idx);
if (!ds) {
printk(KERN_ERR "%s: prepare_ds failed, use MDS\n", __func__);
set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
prepare_to_resend_writes(data);
data->mds_ops->rpc_release(data);
return -EAGAIN;
}
dprintk("%s ino %lu, how %d\n", __func__, data->inode->i_ino, how);
data->write_done_cb = filelayout_commit_done_cb;
data->ds_clp = ds->ds_clp;
fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
if (fh)
data->args.fh = fh;
return nfs_initiate_commit(data, ds->ds_clp->cl_rpcclient,
&filelayout_commit_call_ops, how);
}
/*
* This is only useful while we are using whole file layouts.
*/
static struct pnfs_layout_segment *find_only_write_lseg(struct inode *inode)
{
struct pnfs_layout_segment *lseg, *rv = NULL;
spin_lock(&inode->i_lock);
list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list)
if (lseg->pls_range.iomode == IOMODE_RW)
rv = get_lseg(lseg);
spin_unlock(&inode->i_lock);
return rv;
}
static int alloc_ds_commits(struct inode *inode, struct list_head *list)
{
struct pnfs_layout_segment *lseg;
struct nfs4_filelayout_segment *fl;
struct nfs_write_data *data;
int i, j;
/* Won't need this when non-whole file layout segments are supported
* instead we will use a pnfs_layout_hdr structure */
lseg = find_only_write_lseg(inode);
if (!lseg)
return 0;
fl = FILELAYOUT_LSEG(lseg);
for (i = 0; i < fl->number_of_buckets; i++) {
if (list_empty(&fl->commit_buckets[i]))
continue;
data = nfs_commitdata_alloc();
if (!data)
goto out_bad;
data->ds_commit_index = i;
data->lseg = lseg;
list_add(&data->pages, list);
}
put_lseg(lseg);
return 0;
out_bad:
for (j = i; j < fl->number_of_buckets; j++) {
if (list_empty(&fl->commit_buckets[i]))
continue;
nfs_retry_commit(&fl->commit_buckets[i], lseg);
put_lseg(lseg); /* associated with emptying bucket */
}
put_lseg(lseg);
/* Caller will clean up entries put on list */
return -ENOMEM;
}
/* This follows nfs_commit_list pretty closely */
static int
filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
int how)
{
struct nfs_write_data *data, *tmp;
LIST_HEAD(list);
if (!list_empty(mds_pages)) {
data = nfs_commitdata_alloc();
if (!data)
goto out_bad;
data->lseg = NULL;
list_add(&data->pages, &list);
}
if (alloc_ds_commits(inode, &list))
goto out_bad;
list_for_each_entry_safe(data, tmp, &list, pages) {
list_del_init(&data->pages);
atomic_inc(&NFS_I(inode)->commits_outstanding);
if (!data->lseg) {
nfs_init_commit(data, mds_pages, NULL);
nfs_initiate_commit(data, NFS_CLIENT(inode),
data->mds_ops, how);
} else {
nfs_init_commit(data, &FILELAYOUT_LSEG(data->lseg)->commit_buckets[data->ds_commit_index], data->lseg);
filelayout_initiate_commit(data, how);
}
}
return 0;
out_bad:
list_for_each_entry_safe(data, tmp, &list, pages) {
nfs_retry_commit(&data->pages, data->lseg);
list_del_init(&data->pages);
nfs_commit_free(data);
}
nfs_retry_commit(mds_pages, NULL);
nfs_commit_clear_lock(NFS_I(inode));
return -ENOMEM;
}
static void
filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
{
nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
}
static struct pnfs_layoutdriver_type filelayout_type = {
.id = LAYOUT_NFSV4_1_FILES,
.name = "LAYOUT_NFSV4_1_FILES",
.owner = THIS_MODULE,
.alloc_lseg = filelayout_alloc_lseg,
.free_lseg = filelayout_free_lseg,
.pg_read_ops = &filelayout_pg_read_ops,
.pg_write_ops = &filelayout_pg_write_ops,
.mark_pnfs_commit = filelayout_mark_pnfs_commit,
.choose_commit_list = filelayout_choose_commit_list,
.commit_pagelist = filelayout_commit_pagelist,
.read_pagelist = filelayout_read_pagelist,
.write_pagelist = filelayout_write_pagelist,
.free_deviceid_node = filelayout_free_deveiceid_node,
};
static int __init nfs4filelayout_init(void)
{
printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
__func__);
return pnfs_register_layoutdriver(&filelayout_type);
}
static void __exit nfs4filelayout_exit(void)
{
printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
__func__);
pnfs_unregister_layoutdriver(&filelayout_type);
}
module_init(nfs4filelayout_init);
module_exit(nfs4filelayout_exit);