reactos/base/services/nfsd/pnfs_io.c

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/* NFSv4.1 client for Windows
* Copyright <EFBFBD> 2012 The Regents of the University of Michigan
*
* Olga Kornievskaia <aglo@umich.edu>
* Casey Bodley <cbodley@umich.edu>
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* without any warranty; without even the implied warranty of merchantability
* or fitness for a particular purpose. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA
*/
#include <stdio.h>
#include <process.h>
#include "nfs41_ops.h"
#include "util.h"
#include "daemon_debug.h"
#define IOLVL 2 /* dprintf level for pnfs io logging */
#define file_layout_entry(pos) list_container(pos, pnfs_file_layout, layout.entry)
typedef struct __pnfs_io_pattern {
struct __pnfs_io_thread *threads;
nfs41_root *root;
nfs41_path_fh *meta_file;
const stateid_arg *stateid;
pnfs_layout_state *state;
unsigned char *buffer;
uint64_t offset_start;
uint64_t offset_end;
uint32_t count;
uint32_t default_lease;
} pnfs_io_pattern;
typedef struct __pnfs_io_thread {
nfs41_write_verf verf;
pnfs_io_pattern *pattern;
pnfs_file_layout *layout;
nfs41_path_fh *file;
uint64_t offset;
uint32_t id;
enum stable_how4 stable;
} pnfs_io_thread;
typedef struct __pnfs_io_unit {
unsigned char *buffer;
uint64_t offset;
uint64_t length;
uint32_t stripeid;
uint32_t serverid;
} pnfs_io_unit;
typedef uint32_t (WINAPI *pnfs_io_thread_fn)(void*);
static enum pnfs_status stripe_next_unit(
IN const pnfs_file_layout *layout,
IN uint32_t stripeid,
IN uint64_t *position,
IN uint64_t offset_end,
OUT pnfs_io_unit *io);
/* 13.4.2. Interpreting the File Layout Using Sparse Packing
* http://tools.ietf.org/html/rfc5661#section-13.4.2 */
static enum pnfs_status get_sparse_fh(
IN pnfs_file_layout *layout,
IN nfs41_path_fh *meta_file,
IN uint32_t stripeid,
OUT nfs41_path_fh **file_out)
{
const uint32_t filehandle_count = layout->filehandles.count;
const uint32_t server_count = layout->device->servers.count;
enum pnfs_status status = PNFS_SUCCESS;
if (filehandle_count == server_count) {
const uint32_t serverid = data_server_index(layout->device, stripeid);
*file_out = &layout->filehandles.arr[serverid];
} else if (filehandle_count == 1) {
*file_out = &layout->filehandles.arr[0];
} else if (filehandle_count == 0) {
*file_out = meta_file;
} else {
eprintf("invalid sparse layout! has %u file handles "
"and %u servers\n", filehandle_count, server_count);
status = PNFSERR_INVALID_FH_LIST;
}
return status;
}
/* 13.4.3. Interpreting the File Layout Using Dense Packing
* http://tools.ietf.org/html/rfc5661#section-13.4.3 */
static enum pnfs_status get_dense_fh(
IN pnfs_file_layout *layout,
IN uint32_t stripeid,
OUT nfs41_path_fh **file_out)
{
const uint32_t filehandle_count = layout->filehandles.count;
const uint32_t stripe_count = layout->device->stripes.count;
enum pnfs_status status = PNFS_SUCCESS;
if (filehandle_count == stripe_count) {
*file_out = &layout->filehandles.arr[stripeid];
} else {
eprintf("invalid dense layout! has %u file handles "
"and %u stripes\n", filehandle_count, stripe_count);
status = PNFSERR_INVALID_FH_LIST;
}
return status;
}
static __inline bool_t layout_compatible(
IN const pnfs_layout *layout,
IN enum pnfs_iomode iomode,
IN uint64_t position)
{
return layout->iomode >= iomode
&& layout->offset <= position
&& position < layout->offset + layout->length;
}
/* count stripes for all layout segments that intersect the range
* and have not been covered by previous segments */
static uint32_t thread_count(
IN pnfs_layout_state *state,
IN enum pnfs_iomode iomode,
IN uint64_t offset,
IN uint64_t length)
{
uint64_t position = offset;
struct list_entry *entry;
uint32_t count = 0;
list_for_each(entry, &state->layouts) {
pnfs_file_layout *layout = file_layout_entry(entry);
if (!layout_compatible(&layout->layout, iomode, position))
continue;
position = layout->layout.offset + layout->layout.length;
count += layout->device->stripes.count;
}
return count;
}
static enum pnfs_status thread_init(
IN pnfs_io_pattern *pattern,
IN pnfs_io_thread *thread,
IN pnfs_file_layout *layout,
IN uint32_t stripeid,
IN uint64_t offset)
{
thread->pattern = pattern;
thread->layout = layout;
thread->stable = FILE_SYNC4;
thread->offset = offset;
thread->id = stripeid;
return is_dense(layout) ? get_dense_fh(layout, stripeid, &thread->file)
: get_sparse_fh(layout, pattern->meta_file, stripeid, &thread->file);
}
static enum pnfs_status pattern_threads_init(
IN pnfs_io_pattern *pattern,
IN enum pnfs_iomode iomode,
IN uint64_t offset,
IN uint64_t length)
{
pnfs_io_unit io;
uint64_t position = offset;
struct list_entry *entry;
uint32_t s, t = 0;
enum pnfs_status status = PNFS_SUCCESS;
list_for_each(entry, &pattern->state->layouts) {
pnfs_file_layout *layout = file_layout_entry(entry);
if (!layout_compatible(&layout->layout, iomode, position))
continue;
for (s = 0; s < layout->device->stripes.count; s++) {
uint64_t off = position;
/* does the range contain this stripe? */
status = stripe_next_unit(layout, s, &off, offset + length, &io);
if (status != PNFS_PENDING)
continue;
if (t >= pattern->count) { /* miscounted threads needed? */
status = PNFSERR_NO_LAYOUT;
goto out;
}
status = thread_init(pattern, &pattern->threads[t++], layout, s, off);
if (status)
goto out;
}
position = layout->layout.offset + layout->layout.length;
}
if (position < offset + length) {
/* unable to satisfy the entire range */
status = PNFSERR_NO_LAYOUT;
goto out;
}
/* update the pattern with the actual number of threads used */
pattern->count = t;
out:
return status;
}
static enum pnfs_status pattern_init(
IN pnfs_io_pattern *pattern,
IN nfs41_root *root,
IN nfs41_path_fh *meta_file,
IN const stateid_arg *stateid,
IN pnfs_layout_state *state,
IN unsigned char *buffer,
IN enum pnfs_iomode iomode,
IN uint64_t offset,
IN uint64_t length,
IN uint32_t default_lease)
{
enum pnfs_status status;
/* calculate an upper bound on the number of threads to allocate */
pattern->count = thread_count(state, iomode, offset, length);
pattern->threads = calloc(pattern->count, sizeof(pnfs_io_thread));
if (pattern->threads == NULL) {
status = PNFSERR_RESOURCES;
goto out;
}
/* information shared between threads */
pattern->root = root;
pattern->meta_file = meta_file;
pattern->stateid = stateid;
pattern->state = state;
pattern->buffer = buffer;
pattern->offset_start = offset;
pattern->offset_end = offset + length;
pattern->default_lease = default_lease;
/* initialize a thread for every stripe necessary to cover the range */
status = pattern_threads_init(pattern, iomode, offset, length);
if (status)
goto out_err_free;
/* take a reference on the layout so we don't return it during io */
pnfs_layout_io_start(state);
out:
return status;
out_err_free:
free(pattern->threads);
pattern->threads = NULL;
goto out;
}
static void pattern_free(
IN pnfs_io_pattern *pattern)
{
/* inform the layout that our io is finished */
pnfs_layout_io_finished(pattern->state);
free(pattern->threads);
}
static __inline uint64_t positive_remainder(
IN uint64_t dividend,
IN uint32_t divisor)
{
const uint64_t remainder = dividend % divisor;
return remainder < divisor ? remainder : remainder + divisor;
}
/* return the next unit of the given stripeid */
static enum pnfs_status stripe_next_unit(
IN const pnfs_file_layout *layout,
IN uint32_t stripeid,
IN uint64_t *position,
IN uint64_t offset_end,
OUT pnfs_io_unit *io)
{
const uint32_t unit_size = layout_unit_size(layout);
const uint32_t stripe_count = layout->device->stripes.count;
uint64_t sui = stripe_unit_number(layout, *position, unit_size);
/* advance to the desired stripeid */
sui += abs(stripeid - stripe_index(layout, sui, stripe_count));
io->offset = stripe_unit_offset(layout, sui, unit_size);
if (io->offset < *position) /* don't start before position */
io->offset = *position;
else
*position = io->offset;
io->length = stripe_unit_offset(layout, sui + 1, unit_size);
if (io->length > offset_end) /* don't end past offset_end */
io->length = offset_end;
if (io->offset >= io->length) /* nothing to do, return success */
return PNFS_SUCCESS;
io->length -= io->offset;
if (is_dense(layout)) {
const uint64_t rel_offset = io->offset - layout->pattern_offset;
const uint64_t remainder = positive_remainder(rel_offset, unit_size);
const uint32_t stride = unit_size * stripe_count;
io->offset = (rel_offset / stride) * unit_size + remainder;
}
return PNFS_PENDING;
}
static enum pnfs_status thread_next_unit(
IN pnfs_io_thread *thread,
OUT pnfs_io_unit *io)
{
pnfs_io_pattern *pattern = thread->pattern;
pnfs_layout_state *state = pattern->state;
enum pnfs_status status;
AcquireSRWLockShared(&state->lock);
/* stop io if the layout is recalled */
status = pnfs_layout_recall_status(state, &thread->layout->layout);
if (status)
goto out_unlock;
status = stripe_next_unit(thread->layout, thread->id,
&thread->offset, pattern->offset_end, io);
if (status == PNFS_PENDING)
io->buffer = pattern->buffer + thread->offset - pattern->offset_start;
out_unlock:
ReleaseSRWLockShared(&state->lock);
return status;
}
static enum pnfs_status thread_data_server(
IN pnfs_io_thread *thread,
OUT pnfs_data_server **server_out)
{
pnfs_file_device *device = thread->layout->device;
const uint32_t serverid = data_server_index(device, thread->id);
if (serverid >= device->servers.count)
return PNFSERR_INVALID_DS_INDEX;
*server_out = &device->servers.arr[serverid];
return PNFS_SUCCESS;
}
static enum pnfs_status pattern_join(
IN HANDLE *threads,
IN DWORD count)
{
DWORD status;
/* WaitForMultipleObjects() supports a maximum of 64 objects */
while (count) {
const DWORD n = min(count, MAXIMUM_WAIT_OBJECTS);
status = WaitForMultipleObjects(n, threads, TRUE, INFINITE);
if (status != WAIT_OBJECT_0)
return PNFSERR_RESOURCES;
count -= n;
threads += n;
}
return PNFS_SUCCESS;
}
static enum pnfs_status pattern_fork(
IN pnfs_io_pattern *pattern,
IN pnfs_io_thread_fn thread_fn)
{
HANDLE *threads;
uint32_t i;
enum pnfs_status status = PNFS_SUCCESS;
if (pattern->count == 0)
goto out;
if (pattern->count == 1) {
/* no need to fork if there's only 1 thread */
status = (enum pnfs_status)thread_fn(pattern->threads);
goto out;
}
/* create a thread for each unit that has actual io */
threads = calloc(pattern->count, sizeof(HANDLE));
if (threads == NULL) {
status = PNFSERR_RESOURCES;
goto out;
}
for (i = 0; i < pattern->count; i++) {
threads[i] = (HANDLE)_beginthreadex(NULL, 0,
thread_fn, &pattern->threads[i], 0, NULL);
if (threads[i] == NULL) {
eprintf("_beginthreadex() failed with %d\n", GetLastError());
pattern->count = i; /* join any threads already started */
break;
}
}
/* wait on all threads to finish */
status = pattern_join(threads, pattern->count);
if (status) {
eprintf("pattern_join() failed with %s\n", pnfs_error_string(status));
goto out;
}
for (i = 0; i < pattern->count; i++) {
/* keep track of the most severe error returned by a thread */
DWORD exitcode;
if (GetExitCodeThread(threads[i], &exitcode))
status = max(status, (enum pnfs_status)exitcode);
CloseHandle(threads[i]);
}
free(threads);
out:
return status;
}
static uint64_t pattern_bytes_transferred(
IN pnfs_io_pattern *pattern,
OUT OPTIONAL enum stable_how4 *stable)
{
uint64_t lowest_offset = pattern->offset_end;
uint32_t i;
if (stable) *stable = FILE_SYNC4;
for (i = 0; i < pattern->count; i++) {
lowest_offset = min(lowest_offset, pattern->threads[i].offset);
if (stable) *stable = min(*stable, pattern->threads[i].stable);
}
return lowest_offset - pattern->offset_start;
}
static enum pnfs_status map_ds_error(
IN enum nfsstat4 nfsstat,
IN pnfs_layout_state *state,
IN const pnfs_file_layout *layout)
{
switch (nfsstat) {
case NO_ERROR:
return PNFS_SUCCESS;
/* 13.11 Layout Revocation and Fencing
* http://tools.ietf.org/html/rfc5661#section-13.11
* if we've been fenced, we'll either get ERR_STALE when we PUTFH
* something in layout.filehandles, or ERR_PNFS_NO_LAYOUT when
* attempting to READ or WRITE */
case NFS4ERR_STALE:
case NFS4ERR_PNFS_NO_LAYOUT:
dprintf(IOLVL, "data server fencing detected!\n");
pnfs_layout_recall_fenced(state, &layout->layout);
/* return CHANGED to prevent any further use of the layout */
return PNFSERR_LAYOUT_CHANGED;
default:
return PNFSERR_IO;
}
}
static uint32_t WINAPI file_layout_read_thread(void *args)
{
pnfs_io_unit io;
stateid_arg stateid;
pnfs_io_thread *thread = (pnfs_io_thread*)args;
pnfs_io_pattern *pattern = thread->pattern;
pnfs_data_server *server;
nfs41_client *client;
uint32_t maxreadsize, bytes_read, total_read;
enum pnfs_status status;
enum nfsstat4 nfsstat;
bool_t eof;
dprintf(IOLVL, "--> file_layout_read_thread(%u)\n", thread->id);
/* get the data server for this thread */
status = thread_data_server(thread, &server);
if (status) {
eprintf("thread_data_server() failed with %s\n",
pnfs_error_string(status));
goto out;
}
/* find or establish a client for this data server */
status = pnfs_data_server_client(pattern->root,
server, pattern->default_lease, &client);
if (status) {
eprintf("pnfs_data_server_client() failed with %s\n",
pnfs_error_string(status));
goto out;
}
memcpy(&stateid, pattern->stateid, sizeof(stateid));
stateid.stateid.seqid = 0;
total_read = 0;
while (thread_next_unit(thread, &io) == PNFS_PENDING) {
maxreadsize = max_read_size(client->session, &thread->file->fh);
if (io.length > maxreadsize)
io.length = maxreadsize;
nfsstat = nfs41_read(client->session, thread->file, &stateid,
io.offset, (uint32_t)io.length, io.buffer, &bytes_read, &eof);
if (nfsstat) {
eprintf("nfs41_read() failed with %s\n",
nfs_error_string(nfsstat));
status = map_ds_error(nfsstat, pattern->state, thread->layout);
break;
}
total_read += bytes_read;
thread->offset += bytes_read;
if (eof) {
dprintf(IOLVL, "read thread %u reached eof: offset %llu\n",
thread->id, thread->offset);
status = total_read ? PNFS_SUCCESS : PNFS_READ_EOF;
break;
}
}
out:
dprintf(IOLVL, "<-- file_layout_read_thread(%u) returning %s\n",
thread->id, pnfs_error_string(status));
return status;
}
static uint32_t WINAPI file_layout_write_thread(void *args)
{
pnfs_io_unit io;
stateid_arg stateid;
pnfs_io_thread *thread = (pnfs_io_thread*)args;
pnfs_io_pattern *pattern = thread->pattern;
pnfs_data_server *server;
nfs41_client *client;
const uint64_t offset_start = thread->offset;
uint64_t commit_min, commit_max;
uint32_t maxwritesize, bytes_written, total_written;
enum pnfs_status status;
enum nfsstat4 nfsstat;
dprintf(IOLVL, "--> file_layout_write_thread(%u)\n", thread->id);
/* get the data server for this thread */
status = thread_data_server(thread, &server);
if (status) {
eprintf("thread_data_server() failed with %s\n",
pnfs_error_string(status));
goto out;
}
/* find or establish a client for this data server */
status = pnfs_data_server_client(pattern->root,
server, pattern->default_lease, &client);
if (status) {
eprintf("pnfs_data_server_client() failed with %s\n",
pnfs_error_string(status));
goto out;
}
memcpy(&stateid, pattern->stateid, sizeof(stateid));
stateid.stateid.seqid = 0;
maxwritesize = max_write_size(client->session, &thread->file->fh);
retry_write:
thread->offset = offset_start;
thread->stable = FILE_SYNC4;
commit_min = NFS4_UINT64_MAX;
commit_max = 0;
total_written = 0;
while (thread_next_unit(thread, &io) == PNFS_PENDING) {
if (io.length > maxwritesize)
io.length = maxwritesize;
nfsstat = nfs41_write(client->session, thread->file, &stateid,
io.buffer, (uint32_t)io.length, io.offset, UNSTABLE4,
&bytes_written, &thread->verf, NULL);
if (nfsstat) {
eprintf("nfs41_write() failed with %s\n",
nfs_error_string(nfsstat));
status = map_ds_error(nfsstat, pattern->state, thread->layout);
break;
}
if (!verify_write(&thread->verf, &thread->stable))
goto retry_write;
total_written += bytes_written;
thread->offset += bytes_written;
/* track the range for commit */
if (commit_min > io.offset)
commit_min = io.offset;
if (commit_max < io.offset + io.length)
commit_max = io.offset + io.length;
}
/* nothing to commit */
if (commit_max <= commit_min)
goto out;
/* layout changed; redo all io against metadata server */
if (status == PNFSERR_LAYOUT_CHANGED)
goto out;
/* the data is already in stable storage */
if (thread->stable != UNSTABLE4)
goto out;
/* the metadata server expects us to commit there instead */
if (should_commit_to_mds(thread->layout))
goto out;
dprintf(1, "sending COMMIT to data server for offset=%lld len=%lld\n",
commit_min, commit_max - commit_min);
nfsstat = nfs41_commit(client->session, thread->file,
commit_min, (uint32_t)(commit_max - commit_min), 0, &thread->verf, NULL);
if (nfsstat)
status = map_ds_error(nfsstat, pattern->state, thread->layout);
else if (!verify_commit(&thread->verf)) {
/* resend the writes unless the layout was recalled */
if (status != PNFSERR_LAYOUT_RECALLED)
goto retry_write;
status = PNFSERR_IO;
} else {
/* on successful commit, leave pnfs_status unchanged; if the
* layout was recalled, we still want to return the error */
thread->stable = DATA_SYNC4;
}
out:
dprintf(IOLVL, "<-- file_layout_write_thread(%u) returning %s\n",
thread->id, pnfs_error_string(status));
return status;
}
enum pnfs_status pnfs_read(
IN nfs41_root *root,
IN nfs41_open_state *state,
IN stateid_arg *stateid,
IN pnfs_layout_state *layout,
IN uint64_t offset,
IN uint64_t length,
OUT unsigned char *buffer_out,
OUT ULONG *len_out)
{
pnfs_io_pattern pattern;
enum pnfs_status status;
dprintf(IOLVL, "--> pnfs_read(%llu, %llu)\n", offset, length);
*len_out = 0;
AcquireSRWLockExclusive(&layout->lock);
/* get layouts/devices for the entire range; PNFS_PENDING means we
* dropped the lock to send an rpc, so repeat until it succeeds */
do {
status = pnfs_layout_state_prepare(layout, state->session,
&state->file, stateid, PNFS_IOMODE_READ, offset, length);
} while (status == PNFS_PENDING);
if (status == PNFS_SUCCESS) {
/* interpret the layout and set up threads for io */
status = pattern_init(&pattern, root, &state->file, stateid,
layout, buffer_out, PNFS_IOMODE_READ, offset, length,
state->session->lease_time);
if (status)
eprintf("pattern_init() failed with %s\n",
pnfs_error_string(status));
}
ReleaseSRWLockExclusive(&layout->lock);
if (status)
goto out;
status = pattern_fork(&pattern, file_layout_read_thread);
if (status != PNFS_SUCCESS && status != PNFS_READ_EOF)
goto out_free_pattern;
*len_out = (ULONG)pattern_bytes_transferred(&pattern, NULL);
out_free_pattern:
pattern_free(&pattern);
out:
dprintf(IOLVL, "<-- pnfs_read() returning %s\n",
pnfs_error_string(status));
return status;
}
static enum pnfs_status mds_commit(
IN nfs41_open_state *state,
IN uint64_t offset,
IN uint32_t length,
IN const pnfs_io_pattern *pattern,
OUT nfs41_file_info *info)
{
nfs41_write_verf verf;
enum nfsstat4 nfsstat;
enum pnfs_status status = PNFS_SUCCESS;
uint32_t i;
nfsstat = nfs41_commit(state->session,
&state->file, offset, length, 1, &verf, info);
if (nfsstat) {
eprintf("nfs41_commit() to mds failed with %s\n",
nfs_error_string(nfsstat));
status = PNFSERR_IO;
goto out;
}
/* 13.7. COMMIT through Metadata Server:
* If nfl_util & NFL4_UFLG_COMMIT_THRU_MDS is TRUE, then in order to
* maintain the current NFSv4.1 commit and recovery model, the data
* servers MUST return a common writeverf verifier in all WRITE
* responses for a given file layout, and the metadata server's
* COMMIT implementation must return the same writeverf. */
for (i = 0; i < pattern->count; i++) {
const pnfs_io_thread *thread = &pattern->threads[i];
if (thread->stable != UNSTABLE4) /* already committed */
continue;
if (!should_commit_to_mds(thread->layout)) {
/* commit to mds is not allowed on this layout */
eprintf("mds commit: failed to commit to data server\n");
status = PNFSERR_IO;
break;
}
if (memcmp(verf.verf, thread->verf.verf, NFS4_VERIFIER_SIZE) != 0) {
eprintf("mds commit verifier doesn't match ds write verifiers\n");
status = PNFSERR_IO;
break;
}
}
out:
return status;
}
static enum pnfs_status layout_commit(
IN nfs41_open_state *state,
IN pnfs_layout_state *layout,
IN uint64_t offset,
IN uint64_t length,
OUT nfs41_file_info *info)
{
stateid4 layout_stateid;
uint64_t last_offset = offset + length - 1;
uint64_t *new_last_offset = NULL;
enum nfsstat4 nfsstat;
enum pnfs_status status = PNFS_SUCCESS;
AcquireSRWLockExclusive(&state->lock);
/* if this is past the current eof, update the open state's
* last offset, and pass a pointer to LAYOUTCOMMIT */
if (state->pnfs_last_offset < last_offset ||
(state->pnfs_last_offset == 0 && last_offset == 0)) {
state->pnfs_last_offset = last_offset;
new_last_offset = &last_offset;
}
ReleaseSRWLockExclusive(&state->lock);
AcquireSRWLockShared(&layout->lock);
memcpy(&layout_stateid, &layout->stateid, sizeof(layout_stateid));
ReleaseSRWLockShared(&layout->lock);
dprintf(1, "LAYOUTCOMMIT for offset=%lld len=%lld new_last_offset=%u\n",
offset, length, new_last_offset ? 1 : 0);
nfsstat = pnfs_rpc_layoutcommit(state->session, &state->file,
&layout_stateid, offset, length, new_last_offset, NULL, info);
if (nfsstat) {
dprintf(IOLVL, "pnfs_rpc_layoutcommit() failed with %s\n",
nfs_error_string(nfsstat));
status = PNFSERR_IO;
}
return status;
}
enum pnfs_status pnfs_write(
IN nfs41_root *root,
IN nfs41_open_state *state,
IN stateid_arg *stateid,
IN pnfs_layout_state *layout,
IN uint64_t offset,
IN uint64_t length,
IN unsigned char *buffer,
OUT ULONG *len_out,
OUT nfs41_file_info *info)
{
pnfs_io_pattern pattern;
enum stable_how4 stable;
enum pnfs_status status;
dprintf(IOLVL, "--> pnfs_write(%llu, %llu)\n", offset, length);
*len_out = 0;
AcquireSRWLockExclusive(&layout->lock);
/* get layouts/devices for the entire range; PNFS_PENDING means we
* dropped the lock to send an rpc, so repeat until it succeeds */
do {
status = pnfs_layout_state_prepare(layout, state->session,
&state->file, stateid, PNFS_IOMODE_RW, offset, length);
} while (status == PNFS_PENDING);
if (status == PNFS_SUCCESS) {
/* interpret the layout and set up threads for io */
status = pattern_init(&pattern, root, &state->file, stateid,
layout, buffer, PNFS_IOMODE_RW, offset, length,
state->session->lease_time);
if (status)
eprintf("pattern_init() failed with %s\n",
pnfs_error_string(status));
}
ReleaseSRWLockExclusive(&layout->lock);
if (status)
goto out;
status = pattern_fork(&pattern, file_layout_write_thread);
/* on layout recall, we still attempt to commit what we wrote */
if (status != PNFS_SUCCESS && status != PNFSERR_LAYOUT_RECALLED)
goto out_free_pattern;
*len_out = (ULONG)pattern_bytes_transferred(&pattern, &stable);
if (*len_out == 0)
goto out_free_pattern;
if (stable == UNSTABLE4) {
/* send COMMIT to the mds and verify against all ds writes */
status = mds_commit(state, offset, *len_out, &pattern, info);
} else if (stable == DATA_SYNC4) {
/* send LAYOUTCOMMIT to sync the metadata */
status = layout_commit(state, layout, offset, *len_out, info);
} else {
/* send a GETATTR to update the cached size */
bitmap4 attr_request;
nfs41_superblock_getattr_mask(state->file.fh.superblock, &attr_request);
nfs41_getattr(state->session, &state->file, &attr_request, info);
}
out_free_pattern:
pattern_free(&pattern);
out:
dprintf(IOLVL, "<-- pnfs_write() returning %s\n",
pnfs_error_string(status));
return status;
}