Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/fs/nfs/pagelist.c
 *
 * A set of helper functions for managing NFS read and write requests.
 * The main purpose of these routines is to provide support for the
 * coalescing of several requests into a single RPC call.
 *
 * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
 *
 */
 
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/sched.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs3.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/nfs_mount.h>
#include <linux/export.h>
 
#include "internal.h"
#include "pnfs.h"
#include "nfstrace.h"
 
#define NFSDBG_FACILITY		NFSDBG_PAGECACHE
 
static struct kmem_cache *nfs_page_cachep;
static const struct rpc_call_ops nfs_pgio_common_ops;
 
static struct nfs_pgio_mirror *
nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
{
<------>if (desc->pg_ops->pg_get_mirror)
<------><------>return desc->pg_ops->pg_get_mirror(desc, idx);
<------>return &desc->pg_mirrors[0];
}
 
struct nfs_pgio_mirror *
nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
{
<------>return nfs_pgio_get_mirror(desc, desc->pg_mirror_idx);
}
EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
 
static u32
nfs_pgio_set_current_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
{
<------>if (desc->pg_ops->pg_set_mirror)
<------><------>return desc->pg_ops->pg_set_mirror(desc, idx);
<------>return desc->pg_mirror_idx;
}
 
void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
<------><------>       struct nfs_pgio_header *hdr,
<------><------>       void (*release)(struct nfs_pgio_header *hdr))
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
 
 
<------>hdr->req = nfs_list_entry(mirror->pg_list.next);
<------>hdr->inode = desc->pg_inode;
<------>hdr->cred = nfs_req_openctx(hdr->req)->cred;
<------>hdr->io_start = req_offset(hdr->req);
<------>hdr->good_bytes = mirror->pg_count;
<------>hdr->io_completion = desc->pg_io_completion;
<------>hdr->dreq = desc->pg_dreq;
<------>hdr->release = release;
<------>hdr->completion_ops = desc->pg_completion_ops;
<------>if (hdr->completion_ops->init_hdr)
<------><------>hdr->completion_ops->init_hdr(hdr);
 
<------>hdr->pgio_mirror_idx = desc->pg_mirror_idx;
}
EXPORT_SYMBOL_GPL(nfs_pgheader_init);
 
void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
{
<------>unsigned int new = pos - hdr->io_start;
 
<------>trace_nfs_pgio_error(hdr, error, pos);
<------>if (hdr->good_bytes > new) {
<------><------>hdr->good_bytes = new;
<------><------>clear_bit(NFS_IOHDR_EOF, &hdr->flags);
<------><------>if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags))
<------><------><------>hdr->error = error;
<------>}
}
 
static inline struct nfs_page *
nfs_page_alloc(void)
{
<------>struct nfs_page	*p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
<------>if (p)
<------><------>INIT_LIST_HEAD(&p->wb_list);
<------>return p;
}
 
static inline void
nfs_page_free(struct nfs_page *p)
{
<------>kmem_cache_free(nfs_page_cachep, p);
}
 
/**
 * nfs_iocounter_wait - wait for i/o to complete
 * @l_ctx: nfs_lock_context with io_counter to use
 *
 * returns -ERESTARTSYS if interrupted by a fatal signal.
 * Otherwise returns 0 once the io_count hits 0.
 */
int
nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
{
<------>return wait_var_event_killable(&l_ctx->io_count,
<------><------><------><------>       !atomic_read(&l_ctx->io_count));
}
 
/**
 * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O
 * to complete
 * @task: the rpc_task that should wait
 * @l_ctx: nfs_lock_context with io_counter to check
 *
 * Returns true if there is outstanding I/O to wait on and the
 * task has been put to sleep.
 */
bool
nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx)
{
<------>struct inode *inode = d_inode(l_ctx->open_context->dentry);
<------>bool ret = false;
 
<------>if (atomic_read(&l_ctx->io_count) > 0) {
<------><------>rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
<------><------>ret = true;
<------>}
 
<------>if (atomic_read(&l_ctx->io_count) == 0) {
<------><------>rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
<------><------>ret = false;
<------>}
 
<------>return ret;
}
EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
 
/*
 * nfs_page_lock_head_request - page lock the head of the page group
 * @req: any member of the page group
 */
struct nfs_page *
nfs_page_group_lock_head(struct nfs_page *req)
{
<------>struct nfs_page *head = req->wb_head;
 
<------>while (!nfs_lock_request(head)) {
<------><------>int ret = nfs_wait_on_request(head);
<------><------>if (ret < 0)
<------><------><------>return ERR_PTR(ret);
<------>}
<------>if (head != req)
<------><------>kref_get(&head->wb_kref);
<------>return head;
}
 
/*
 * nfs_unroll_locks -  unlock all newly locked reqs and wait on @req
 * @head: head request of page group, must be holding head lock
 * @req: request that couldn't lock and needs to wait on the req bit lock
 *
 * This is a helper function for nfs_lock_and_join_requests
 * returns 0 on success, < 0 on error.
 */
static void
nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req)
{
<------>struct nfs_page *tmp;
 
<------>/* relinquish all the locks successfully grabbed this run */
<------>for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) {
<------><------>if (!kref_read(&tmp->wb_kref))
<------><------><------>continue;
<------><------>nfs_unlock_and_release_request(tmp);
<------>}
}
 
/*
 * nfs_page_group_lock_subreq -  try to lock a subrequest
 * @head: head request of page group
 * @subreq: request to lock
 *
 * This is a helper function for nfs_lock_and_join_requests which
 * must be called with the head request and page group both locked.
 * On error, it returns with the page group unlocked.
 */
static int
nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq)
{
<------>int ret;
 
<------>if (!kref_get_unless_zero(&subreq->wb_kref))
<------><------>return 0;
<------>while (!nfs_lock_request(subreq)) {
<------><------>nfs_page_group_unlock(head);
<------><------>ret = nfs_wait_on_request(subreq);
<------><------>if (!ret)
<------><------><------>ret = nfs_page_group_lock(head);
<------><------>if (ret < 0) {
<------><------><------>nfs_unroll_locks(head, subreq);
<------><------><------>nfs_release_request(subreq);
<------><------><------>return ret;
<------><------>}
<------>}
<------>return 0;
}
 
/*
 * nfs_page_group_lock_subrequests -  try to lock the subrequests
 * @head: head request of page group
 *
 * This is a helper function for nfs_lock_and_join_requests which
 * must be called with the head request locked.
 */
int nfs_page_group_lock_subrequests(struct nfs_page *head)
{
<------>struct nfs_page *subreq;
<------>int ret;
 
<------>ret = nfs_page_group_lock(head);
<------>if (ret < 0)
<------><------>return ret;
<------>/* lock each request in the page group */
<------>for (subreq = head->wb_this_page; subreq != head;
<------><------><------>subreq = subreq->wb_this_page) {
<------><------>ret = nfs_page_group_lock_subreq(head, subreq);
<------><------>if (ret < 0)
<------><------><------>return ret;
<------>}
<------>nfs_page_group_unlock(head);
<------>return 0;
}
 
/*
 * nfs_page_set_headlock - set the request PG_HEADLOCK
 * @req: request that is to be locked
 *
 * this lock must be held when modifying req->wb_head
 *
 * return 0 on success, < 0 on error
 */
int
nfs_page_set_headlock(struct nfs_page *req)
{
<------>if (!test_and_set_bit(PG_HEADLOCK, &req->wb_flags))
<------><------>return 0;
 
<------>set_bit(PG_CONTENDED1, &req->wb_flags);
<------>smp_mb__after_atomic();
<------>return wait_on_bit_lock(&req->wb_flags, PG_HEADLOCK,
<------><------><------><------>TASK_UNINTERRUPTIBLE);
}
 
/*
 * nfs_page_clear_headlock - clear the request PG_HEADLOCK
 * @req: request that is to be locked
 */
void
nfs_page_clear_headlock(struct nfs_page *req)
{
<------>smp_mb__before_atomic();
<------>clear_bit(PG_HEADLOCK, &req->wb_flags);
<------>smp_mb__after_atomic();
<------>if (!test_bit(PG_CONTENDED1, &req->wb_flags))
<------><------>return;
<------>wake_up_bit(&req->wb_flags, PG_HEADLOCK);
}
 
/*
 * nfs_page_group_lock - lock the head of the page group
 * @req: request in group that is to be locked
 *
 * this lock must be held when traversing or modifying the page
 * group list
 *
 * return 0 on success, < 0 on error
 */
int
nfs_page_group_lock(struct nfs_page *req)
{
<------>int ret;
 
<------>ret = nfs_page_set_headlock(req);
<------>if (ret || req->wb_head == req)
<------><------>return ret;
<------>return nfs_page_set_headlock(req->wb_head);
}
 
/*
 * nfs_page_group_unlock - unlock the head of the page group
 * @req: request in group that is to be unlocked
 */
void
nfs_page_group_unlock(struct nfs_page *req)
{
<------>if (req != req->wb_head)
<------><------>nfs_page_clear_headlock(req->wb_head);
<------>nfs_page_clear_headlock(req);
}
 
/*
 * nfs_page_group_sync_on_bit_locked
 *
 * must be called with page group lock held
 */
static bool
nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
{
<------>struct nfs_page *head = req->wb_head;
<------>struct nfs_page *tmp;
 
<------>WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
<------>WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
 
<------>tmp = req->wb_this_page;
<------>while (tmp != req) {
<------><------>if (!test_bit(bit, &tmp->wb_flags))
<------><------><------>return false;
<------><------>tmp = tmp->wb_this_page;
<------>}
 
<------>/* true! reset all bits */
<------>tmp = req;
<------>do {
<------><------>clear_bit(bit, &tmp->wb_flags);
<------><------>tmp = tmp->wb_this_page;
<------>} while (tmp != req);
 
<------>return true;
}
 
/*
 * nfs_page_group_sync_on_bit - set bit on current request, but only
 *   return true if the bit is set for all requests in page group
 * @req - request in page group
 * @bit - PG_* bit that is used to sync page group
 */
bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
{
<------>bool ret;
 
<------>nfs_page_group_lock(req);
<------>ret = nfs_page_group_sync_on_bit_locked(req, bit);
<------>nfs_page_group_unlock(req);
 
<------>return ret;
}
 
/*
 * nfs_page_group_init - Initialize the page group linkage for @req
 * @req - a new nfs request
 * @prev - the previous request in page group, or NULL if @req is the first
 *         or only request in the group (the head).
 */
static inline void
nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
{
<------>struct inode *inode;
<------>WARN_ON_ONCE(prev == req);
 
<------>if (!prev) {
<------><------>/* a head request */
<------><------>req->wb_head = req;
<------><------>req->wb_this_page = req;
<------>} else {
<------><------>/* a subrequest */
<------><------>WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
<------><------>WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
<------><------>req->wb_head = prev->wb_head;
<------><------>req->wb_this_page = prev->wb_this_page;
<------><------>prev->wb_this_page = req;
 
<------><------>/* All subrequests take a ref on the head request until
<------><------> * nfs_page_group_destroy is called */
<------><------>kref_get(&req->wb_head->wb_kref);
 
<------><------>/* grab extra ref and bump the request count if head request
<------><------> * has extra ref from the write/commit path to handle handoff
<------><------> * between write and commit lists. */
<------><------>if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
<------><------><------>inode = page_file_mapping(req->wb_page)->host;
<------><------><------>set_bit(PG_INODE_REF, &req->wb_flags);
<------><------><------>kref_get(&req->wb_kref);
<------><------><------>atomic_long_inc(&NFS_I(inode)->nrequests);
<------><------>}
<------>}
}
 
/*
 * nfs_page_group_destroy - sync the destruction of page groups
 * @req - request that no longer needs the page group
 *
 * releases the page group reference from each member once all
 * members have called this function.
 */
static void
nfs_page_group_destroy(struct kref *kref)
{
<------>struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
<------>struct nfs_page *head = req->wb_head;
<------>struct nfs_page *tmp, *next;
 
<------>if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
<------><------>goto out;
 
<------>tmp = req;
<------>do {
<------><------>next = tmp->wb_this_page;
<------><------>/* unlink and free */
<------><------>tmp->wb_this_page = tmp;
<------><------>tmp->wb_head = tmp;
<------><------>nfs_free_request(tmp);
<------><------>tmp = next;
<------>} while (tmp != req);
out:
<------>/* subrequests must release the ref on the head request */
<------>if (head != req)
<------><------>nfs_release_request(head);
}
 
static struct nfs_page *
__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,
<------><------>   unsigned int pgbase, unsigned int offset,
<------><------>   unsigned int count)
{
<------>struct nfs_page		*req;
<------>struct nfs_open_context *ctx = l_ctx->open_context;
 
<------>if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
<------><------>return ERR_PTR(-EBADF);
<------>/* try to allocate the request struct */
<------>req = nfs_page_alloc();
<------>if (req == NULL)
<------><------>return ERR_PTR(-ENOMEM);
 
<------>req->wb_lock_context = l_ctx;
<------>refcount_inc(&l_ctx->count);
<------>atomic_inc(&l_ctx->io_count);
 
<------>/* Initialize the request struct. Initially, we assume a
<------> * long write-back delay. This will be adjusted in
<------> * update_nfs_request below if the region is not locked. */
<------>req->wb_page    = page;
<------>if (page) {
<------><------>req->wb_index = page_index(page);
<------><------>get_page(page);
<------>}
<------>req->wb_offset  = offset;
<------>req->wb_pgbase	= pgbase;
<------>req->wb_bytes   = count;
<------>kref_init(&req->wb_kref);
<------>req->wb_nio = 0;
<------>return req;
}
 
/**
 * nfs_create_request - Create an NFS read/write request.
 * @ctx: open context to use
 * @page: page to write
 * @offset: starting offset within the page for the write
 * @count: number of bytes to read/write
 *
 * The page must be locked by the caller. This makes sure we never
 * create two different requests for the same page.
 * User should ensure it is safe to sleep in this function.
 */
struct nfs_page *
nfs_create_request(struct nfs_open_context *ctx, struct page *page,
<------><------>   unsigned int offset, unsigned int count)
{
<------>struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
<------>struct nfs_page *ret;
 
<------>if (IS_ERR(l_ctx))
<------><------>return ERR_CAST(l_ctx);
<------>ret = __nfs_create_request(l_ctx, page, offset, offset, count);
<------>if (!IS_ERR(ret))
<------><------>nfs_page_group_init(ret, NULL);
<------>nfs_put_lock_context(l_ctx);
<------>return ret;
}
 
static struct nfs_page *
nfs_create_subreq(struct nfs_page *req,
<------><------>  unsigned int pgbase,
<------><------>  unsigned int offset,
<------><------>  unsigned int count)
{
<------>struct nfs_page *last;
<------>struct nfs_page *ret;
 
<------>ret = __nfs_create_request(req->wb_lock_context, req->wb_page,
<------><------><------>pgbase, offset, count);
<------>if (!IS_ERR(ret)) {
<------><------>/* find the last request */
<------><------>for (last = req->wb_head;
<------><------>     last->wb_this_page != req->wb_head;
<------><------>     last = last->wb_this_page)
<------><------><------>;
 
<------><------>nfs_lock_request(ret);
<------><------>ret->wb_index = req->wb_index;
<------><------>nfs_page_group_init(ret, last);
<------><------>ret->wb_nio = req->wb_nio;
<------>}
<------>return ret;
}
 
/**
 * nfs_unlock_request - Unlock request and wake up sleepers.
 * @req: pointer to request
 */
void nfs_unlock_request(struct nfs_page *req)
{
<------>if (!NFS_WBACK_BUSY(req)) {
<------><------>printk(KERN_ERR "NFS: Invalid unlock attempted\n");
<------><------>BUG();
<------>}
<------>smp_mb__before_atomic();
<------>clear_bit(PG_BUSY, &req->wb_flags);
<------>smp_mb__after_atomic();
<------>if (!test_bit(PG_CONTENDED2, &req->wb_flags))
<------><------>return;
<------>wake_up_bit(&req->wb_flags, PG_BUSY);
}
 
/**
 * nfs_unlock_and_release_request - Unlock request and release the nfs_page
 * @req: pointer to request
 */
void nfs_unlock_and_release_request(struct nfs_page *req)
{
<------>nfs_unlock_request(req);
<------>nfs_release_request(req);
}
 
/*
 * nfs_clear_request - Free up all resources allocated to the request
 * @req:
 *
 * Release page and open context resources associated with a read/write
 * request after it has completed.
 */
static void nfs_clear_request(struct nfs_page *req)
{
<------>struct page *page = req->wb_page;
<------>struct nfs_lock_context *l_ctx = req->wb_lock_context;
<------>struct nfs_open_context *ctx;
 
<------>if (page != NULL) {
<------><------>put_page(page);
<------><------>req->wb_page = NULL;
<------>}
<------>if (l_ctx != NULL) {
<------><------>if (atomic_dec_and_test(&l_ctx->io_count)) {
<------><------><------>wake_up_var(&l_ctx->io_count);
<------><------><------>ctx = l_ctx->open_context;
<------><------><------>if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
<------><------><------><------>rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
<------><------>}
<------><------>nfs_put_lock_context(l_ctx);
<------><------>req->wb_lock_context = NULL;
<------>}
}
 
/**
 * nfs_release_request - Release the count on an NFS read/write request
 * @req: request to release
 *
 * Note: Should never be called with the spinlock held!
 */
void nfs_free_request(struct nfs_page *req)
{
<------>WARN_ON_ONCE(req->wb_this_page != req);
 
<------>/* extra debug: make sure no sync bits are still set */
<------>WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
<------>WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
<------>WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
<------>WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
<------>WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
 
<------>/* Release struct file and open context */
<------>nfs_clear_request(req);
<------>nfs_page_free(req);
}
 
void nfs_release_request(struct nfs_page *req)
{
<------>kref_put(&req->wb_kref, nfs_page_group_destroy);
}
EXPORT_SYMBOL_GPL(nfs_release_request);
 
/**
 * nfs_wait_on_request - Wait for a request to complete.
 * @req: request to wait upon.
 *
 * Interruptible by fatal signals only.
 * The user is responsible for holding a count on the request.
 */
int
nfs_wait_on_request(struct nfs_page *req)
{
<------>if (!test_bit(PG_BUSY, &req->wb_flags))
<------><------>return 0;
<------>set_bit(PG_CONTENDED2, &req->wb_flags);
<------>smp_mb__after_atomic();
<------>return wait_on_bit_io(&req->wb_flags, PG_BUSY,
<------><------><------>      TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL_GPL(nfs_wait_on_request);
 
/*
 * nfs_generic_pg_test - determine if requests can be coalesced
 * @desc: pointer to descriptor
 * @prev: previous request in desc, or NULL
 * @req: this request
 *
 * Returns zero if @req cannot be coalesced into @desc, otherwise it returns
 * the size of the request.
 */
size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
<------><------><------>   struct nfs_page *prev, struct nfs_page *req)
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
 
 
<------>if (mirror->pg_count > mirror->pg_bsize) {
<------><------>/* should never happen */
<------><------>WARN_ON_ONCE(1);
<------><------>return 0;
<------>}
 
<------>/*
<------> * Limit the request size so that we can still allocate a page array
<------> * for it without upsetting the slab allocator.
<------> */
<------>if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
<------><------><------>sizeof(struct page *) > PAGE_SIZE)
<------><------>return 0;
 
<------>return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
}
EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
 
struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
{
<------>struct nfs_pgio_header *hdr = ops->rw_alloc_header();
 
<------>if (hdr) {
<------><------>INIT_LIST_HEAD(&hdr->pages);
<------><------>hdr->rw_ops = ops;
<------>}
<------>return hdr;
}
EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
 
/**
 * nfs_pgio_data_destroy - make @hdr suitable for reuse
 *
 * Frees memory and releases refs from nfs_generic_pgio, so that it may
 * be called again.
 *
 * @hdr: A header that has had nfs_generic_pgio called
 */
static void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
{
<------>if (hdr->args.context)
<------><------>put_nfs_open_context(hdr->args.context);
<------>if (hdr->page_array.pagevec != hdr->page_array.page_array)
<------><------>kfree(hdr->page_array.pagevec);
}
 
/*
 * nfs_pgio_header_free - Free a read or write header
 * @hdr: The header to free
 */
void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
{
<------>nfs_pgio_data_destroy(hdr);
<------>hdr->rw_ops->rw_free_header(hdr);
}
EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
 
/**
 * nfs_pgio_rpcsetup - Set up arguments for a pageio call
 * @hdr: The pageio hdr
 * @count: Number of bytes to read
 * @how: How to commit data (writes only)
 * @cinfo: Commit information for the call (writes only)
 */
static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
<------><------><------>      unsigned int count,
<------><------><------>      int how, struct nfs_commit_info *cinfo)
{
<------>struct nfs_page *req = hdr->req;
 
<------>/* Set up the RPC argument and reply structs
<------> * NB: take care not to mess about with hdr->commit et al. */
 
<------>hdr->args.fh     = NFS_FH(hdr->inode);
<------>hdr->args.offset = req_offset(req);
<------>/* pnfs_set_layoutcommit needs this */
<------>hdr->mds_offset = hdr->args.offset;
<------>hdr->args.pgbase = req->wb_pgbase;
<------>hdr->args.pages  = hdr->page_array.pagevec;
<------>hdr->args.count  = count;
<------>hdr->args.context = get_nfs_open_context(nfs_req_openctx(req));
<------>hdr->args.lock_context = req->wb_lock_context;
<------>hdr->args.stable  = NFS_UNSTABLE;
<------>switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
<------>case 0:
<------><------>break;
<------>case FLUSH_COND_STABLE:
<------><------>if (nfs_reqs_to_commit(cinfo))
<------><------><------>break;
<------><------>fallthrough;
<------>default:
<------><------>hdr->args.stable = NFS_FILE_SYNC;
<------>}
 
<------>hdr->res.fattr   = &hdr->fattr;
<------>hdr->res.count   = 0;
<------>hdr->res.eof     = 0;
<------>hdr->res.verf    = &hdr->verf;
<------>nfs_fattr_init(&hdr->fattr);
}
 
/**
 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
 * @task: The current task
 * @calldata: pageio header to prepare
 */
static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
{
<------>struct nfs_pgio_header *hdr = calldata;
<------>int err;
<------>err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
<------>if (err)
<------><------>rpc_exit(task, err);
}
 
int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
<------><------>      const struct cred *cred, const struct nfs_rpc_ops *rpc_ops,
<------><------>      const struct rpc_call_ops *call_ops, int how, int flags)
{
<------>struct rpc_task *task;
<------>struct rpc_message msg = {
<------><------>.rpc_argp = &hdr->args,
<------><------>.rpc_resp = &hdr->res,
<------><------>.rpc_cred = cred,
<------>};
<------>struct rpc_task_setup task_setup_data = {
<------><------>.rpc_client = clnt,
<------><------>.task = &hdr->task,
<------><------>.rpc_message = &msg,
<------><------>.callback_ops = call_ops,
<------><------>.callback_data = hdr,
<------><------>.workqueue = nfsiod_workqueue,
<------><------>.flags = RPC_TASK_ASYNC | flags,
<------>};
 
<------>hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
 
<------>dprintk("NFS: initiated pgio call "
<------><------>"(req %s/%llu, %u bytes @ offset %llu)\n",
<------><------>hdr->inode->i_sb->s_id,
<------><------>(unsigned long long)NFS_FILEID(hdr->inode),
<------><------>hdr->args.count,
<------><------>(unsigned long long)hdr->args.offset);
 
<------>task = rpc_run_task(&task_setup_data);
<------>if (IS_ERR(task))
<------><------>return PTR_ERR(task);
<------>rpc_put_task(task);
<------>return 0;
}
EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
 
/**
 * nfs_pgio_error - Clean up from a pageio error
 * @hdr: pageio header
 */
static void nfs_pgio_error(struct nfs_pgio_header *hdr)
{
<------>set_bit(NFS_IOHDR_REDO, &hdr->flags);
<------>hdr->completion_ops->completion(hdr);
}
 
/**
 * nfs_pgio_release - Release pageio data
 * @calldata: The pageio header to release
 */
static void nfs_pgio_release(void *calldata)
{
<------>struct nfs_pgio_header *hdr = calldata;
<------>hdr->completion_ops->completion(hdr);
}
 
static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
<------><------><------><------>   unsigned int bsize)
{
<------>INIT_LIST_HEAD(&mirror->pg_list);
<------>mirror->pg_bytes_written = 0;
<------>mirror->pg_count = 0;
<------>mirror->pg_bsize = bsize;
<------>mirror->pg_base = 0;
<------>mirror->pg_recoalesce = 0;
}
 
/**
 * nfs_pageio_init - initialise a page io descriptor
 * @desc: pointer to descriptor
 * @inode: pointer to inode
 * @pg_ops: pointer to pageio operations
 * @compl_ops: pointer to pageio completion operations
 * @rw_ops: pointer to nfs read/write operations
 * @bsize: io block size
 * @io_flags: extra parameters for the io function
 */
void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
<------><------>     struct inode *inode,
<------><------>     const struct nfs_pageio_ops *pg_ops,
<------><------>     const struct nfs_pgio_completion_ops *compl_ops,
<------><------>     const struct nfs_rw_ops *rw_ops,
<------><------>     size_t bsize,
<------><------>     int io_flags)
{
<------>desc->pg_moreio = 0;
<------>desc->pg_inode = inode;
<------>desc->pg_ops = pg_ops;
<------>desc->pg_completion_ops = compl_ops;
<------>desc->pg_rw_ops = rw_ops;
<------>desc->pg_ioflags = io_flags;
<------>desc->pg_error = 0;
<------>desc->pg_lseg = NULL;
<------>desc->pg_io_completion = NULL;
<------>desc->pg_dreq = NULL;
<------>desc->pg_bsize = bsize;
 
<------>desc->pg_mirror_count = 1;
<------>desc->pg_mirror_idx = 0;
 
<------>desc->pg_mirrors_dynamic = NULL;
<------>desc->pg_mirrors = desc->pg_mirrors_static;
<------>nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
<------>desc->pg_maxretrans = 0;
}
 
/**
 * nfs_pgio_result - Basic pageio error handling
 * @task: The task that ran
 * @calldata: Pageio header to check
 */
static void nfs_pgio_result(struct rpc_task *task, void *calldata)
{
<------>struct nfs_pgio_header *hdr = calldata;
<------>struct inode *inode = hdr->inode;
 
<------>dprintk("NFS: %s: %5u, (status %d)\n", __func__,
<------><------>task->tk_pid, task->tk_status);
 
<------>if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
<------><------>return;
<------>if (task->tk_status < 0)
<------><------>nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
<------>else
<------><------>hdr->rw_ops->rw_result(task, hdr);
}
 
/*
 * Create an RPC task for the given read or write request and kick it.
 * The page must have been locked by the caller.
 *
 * It may happen that the page we're passed is not marked dirty.
 * This is the case if nfs_updatepage detects a conflicting request
 * that has been written but not committed.
 */
int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
<------><------>     struct nfs_pgio_header *hdr)
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
 
<------>struct nfs_page		*req;
<------>struct page		**pages,
<------><------><------><------>*last_page;
<------>struct list_head *head = &mirror->pg_list;
<------>struct nfs_commit_info cinfo;
<------>struct nfs_page_array *pg_array = &hdr->page_array;
<------>unsigned int pagecount, pageused;
<------>gfp_t gfp_flags = GFP_KERNEL;
 
<------>pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
<------>pg_array->npages = pagecount;
 
<------>if (pagecount <= ARRAY_SIZE(pg_array->page_array))
<------><------>pg_array->pagevec = pg_array->page_array;
<------>else {
<------><------>pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
<------><------>if (!pg_array->pagevec) {
<------><------><------>pg_array->npages = 0;
<------><------><------>nfs_pgio_error(hdr);
<------><------><------>desc->pg_error = -ENOMEM;
<------><------><------>return desc->pg_error;
<------><------>}
<------>}
 
<------>nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
<------>pages = hdr->page_array.pagevec;
<------>last_page = NULL;
<------>pageused = 0;
<------>while (!list_empty(head)) {
<------><------>req = nfs_list_entry(head->next);
<------><------>nfs_list_move_request(req, &hdr->pages);
 
<------><------>if (!last_page || last_page != req->wb_page) {
<------><------><------>pageused++;
<------><------><------>if (pageused > pagecount)
<------><------><------><------>break;
<------><------><------>*pages++ = last_page = req->wb_page;
<------><------>}
<------>}
<------>if (WARN_ON_ONCE(pageused != pagecount)) {
<------><------>nfs_pgio_error(hdr);
<------><------>desc->pg_error = -EINVAL;
<------><------>return desc->pg_error;
<------>}
 
<------>if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
<------>    (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
<------><------>desc->pg_ioflags &= ~FLUSH_COND_STABLE;
 
<------>/* Set up the argument struct */
<------>nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
<------>desc->pg_rpc_callops = &nfs_pgio_common_ops;
<------>return 0;
}
EXPORT_SYMBOL_GPL(nfs_generic_pgio);
 
static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
{
<------>struct nfs_pgio_header *hdr;
<------>int ret;
 
<------>hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
<------>if (!hdr) {
<------><------>desc->pg_error = -ENOMEM;
<------><------>return desc->pg_error;
<------>}
<------>nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
<------>ret = nfs_generic_pgio(desc, hdr);
<------>if (ret == 0)
<------><------>ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
<------><------><------><------><------>hdr,
<------><------><------><------><------>hdr->cred,
<------><------><------><------><------>NFS_PROTO(hdr->inode),
<------><------><------><------><------>desc->pg_rpc_callops,
<------><------><------><------><------>desc->pg_ioflags,
<------><------><------><------><------>RPC_TASK_CRED_NOREF);
<------>return ret;
}
 
static struct nfs_pgio_mirror *
nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
<------><------>unsigned int mirror_count)
{
<------>struct nfs_pgio_mirror *ret;
<------>unsigned int i;
 
<------>kfree(desc->pg_mirrors_dynamic);
<------>desc->pg_mirrors_dynamic = NULL;
<------>if (mirror_count == 1)
<------><------>return desc->pg_mirrors_static;
<------>ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_KERNEL);
<------>if (ret != NULL) {
<------><------>for (i = 0; i < mirror_count; i++)
<------><------><------>nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
<------><------>desc->pg_mirrors_dynamic = ret;
<------>}
<------>return ret;
}
 
/*
 * nfs_pageio_setup_mirroring - determine if mirroring is to be used
 *				by calling the pg_get_mirror_count op
 */
static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
<------><------><------><------>       struct nfs_page *req)
{
<------>unsigned int mirror_count = 1;
 
<------>if (pgio->pg_ops->pg_get_mirror_count)
<------><------>mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
<------>if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0)
<------><------>return;
 
<------>if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
<------><------>pgio->pg_error = -EINVAL;
<------><------>return;
<------>}
 
<------>pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count);
<------>if (pgio->pg_mirrors == NULL) {
<------><------>pgio->pg_error = -ENOMEM;
<------><------>pgio->pg_mirrors = pgio->pg_mirrors_static;
<------><------>mirror_count = 1;
<------>}
<------>pgio->pg_mirror_count = mirror_count;
}
 
static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
{
<------>pgio->pg_mirror_count = 1;
<------>pgio->pg_mirror_idx = 0;
<------>pgio->pg_mirrors = pgio->pg_mirrors_static;
<------>kfree(pgio->pg_mirrors_dynamic);
<------>pgio->pg_mirrors_dynamic = NULL;
}
 
static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
<------><------>const struct nfs_lock_context *l2)
{
<------>return l1->lockowner == l2->lockowner;
}
 
/**
 * nfs_coalesce_size - test two requests for compatibility
 * @prev: pointer to nfs_page
 * @req: pointer to nfs_page
 * @pgio: pointer to nfs_pagio_descriptor
 *
 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
 * page data area they describe is contiguous, and that their RPC
 * credentials, NFSv4 open state, and lockowners are the same.
 *
 * Returns size of the request that can be coalesced
 */
static unsigned int nfs_coalesce_size(struct nfs_page *prev,
<------><------><------><------>      struct nfs_page *req,
<------><------><------><------>      struct nfs_pageio_descriptor *pgio)
{
<------>struct file_lock_context *flctx;
 
<------>if (prev) {
<------><------>if (!nfs_match_open_context(nfs_req_openctx(req), nfs_req_openctx(prev)))
<------><------><------>return 0;
<------><------>flctx = d_inode(nfs_req_openctx(req)->dentry)->i_flctx;
<------><------>if (flctx != NULL &&
<------><------>    !(list_empty_careful(&flctx->flc_posix) &&
<------><------>      list_empty_careful(&flctx->flc_flock)) &&
<------><------>    !nfs_match_lock_context(req->wb_lock_context,
<------><------><------><------><------>    prev->wb_lock_context))
<------><------><------>return 0;
<------><------>if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
<------><------><------>return 0;
<------><------>if (req->wb_page == prev->wb_page) {
<------><------><------>if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
<------><------><------><------>return 0;
<------><------>} else {
<------><------><------>if (req->wb_pgbase != 0 ||
<------><------><------>    prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE)
<------><------><------><------>return 0;
<------><------>}
<------>}
<------>return pgio->pg_ops->pg_test(pgio, prev, req);
}
 
/**
 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
 * @desc: destination io descriptor
 * @req: request
 *
 * If the request 'req' was successfully coalesced into the existing list
 * of pages 'desc', it returns the size of req.
 */
static unsigned int
nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
<------><------>struct nfs_page *req)
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
<------>struct nfs_page *prev = NULL;
<------>unsigned int size;
 
<------>if (list_empty(&mirror->pg_list)) {
<------><------>if (desc->pg_ops->pg_init)
<------><------><------>desc->pg_ops->pg_init(desc, req);
<------><------>if (desc->pg_error < 0)
<------><------><------>return 0;
<------><------>mirror->pg_base = req->wb_pgbase;
<------><------>mirror->pg_count = 0;
<------><------>mirror->pg_recoalesce = 0;
<------>} else
<------><------>prev = nfs_list_entry(mirror->pg_list.prev);
 
<------>if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) {
<------><------>if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR)
<------><------><------>desc->pg_error = -ETIMEDOUT;
<------><------>else
<------><------><------>desc->pg_error = -EIO;
<------><------>return 0;
<------>}
 
<------>size = nfs_coalesce_size(prev, req, desc);
<------>if (size < req->wb_bytes)
<------><------>return size;
<------>nfs_list_move_request(req, &mirror->pg_list);
<------>mirror->pg_count += req->wb_bytes;
<------>return req->wb_bytes;
}
 
/*
 * Helper for nfs_pageio_add_request and nfs_pageio_complete
 */
static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
 
<------>if (!list_empty(&mirror->pg_list)) {
<------><------>int error = desc->pg_ops->pg_doio(desc);
<------><------>if (error < 0)
<------><------><------>desc->pg_error = error;
<------><------>if (list_empty(&mirror->pg_list)) {
<------><------><------>mirror->pg_bytes_written += mirror->pg_count;
<------><------><------>mirror->pg_count = 0;
<------><------><------>mirror->pg_base = 0;
<------><------><------>mirror->pg_recoalesce = 0;
<------><------>}
<------>}
}
 
static void
nfs_pageio_cleanup_request(struct nfs_pageio_descriptor *desc,
<------><------>struct nfs_page *req)
{
<------>LIST_HEAD(head);
 
<------>nfs_list_move_request(req, &head);
<------>desc->pg_completion_ops->error_cleanup(&head, desc->pg_error);
}
 
/**
 * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
 * @desc: destination io descriptor
 * @req: request
 *
 * This may split a request into subrequests which are all part of the
 * same page group. If so, it will submit @req as the last one, to ensure
 * the pointer to @req is still valid in case of failure.
 *
 * Returns true if the request 'req' was successfully coalesced into the
 * existing list of pages 'desc'.
 */
static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
<------><------><------>   struct nfs_page *req)
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
<------>struct nfs_page *subreq;
<------>unsigned int size, subreq_size;
 
<------>nfs_page_group_lock(req);
 
<------>subreq = req;
<------>subreq_size = subreq->wb_bytes;
<------>for(;;) {
<------><------>size = nfs_pageio_do_add_request(desc, subreq);
<------><------>if (size == subreq_size) {
<------><------><------>/* We successfully submitted a request */
<------><------><------>if (subreq == req)
<------><------><------><------>break;
<------><------><------>req->wb_pgbase += size;
<------><------><------>req->wb_bytes -= size;
<------><------><------>req->wb_offset += size;
<------><------><------>subreq_size = req->wb_bytes;
<------><------><------>subreq = req;
<------><------><------>continue;
<------><------>}
<------><------>if (WARN_ON_ONCE(subreq != req)) {
<------><------><------>nfs_page_group_unlock(req);
<------><------><------>nfs_pageio_cleanup_request(desc, subreq);
<------><------><------>subreq = req;
<------><------><------>subreq_size = req->wb_bytes;
<------><------><------>nfs_page_group_lock(req);
<------><------>}
<------><------>if (!size) {
<------><------><------>/* Can't coalesce any more, so do I/O */
<------><------><------>nfs_page_group_unlock(req);
<------><------><------>desc->pg_moreio = 1;
<------><------><------>nfs_pageio_doio(desc);
<------><------><------>if (desc->pg_error < 0 || mirror->pg_recoalesce)
<------><------><------><------>return 0;
<------><------><------>/* retry add_request for this subreq */
<------><------><------>nfs_page_group_lock(req);
<------><------><------>continue;
<------><------>}
<------><------>subreq = nfs_create_subreq(req, req->wb_pgbase,
<------><------><------><------>req->wb_offset, size);
<------><------>if (IS_ERR(subreq))
<------><------><------>goto err_ptr;
<------><------>subreq_size = size;
<------>}
 
<------>nfs_page_group_unlock(req);
<------>return 1;
err_ptr:
<------>desc->pg_error = PTR_ERR(subreq);
<------>nfs_page_group_unlock(req);
<------>return 0;
}
 
static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
{
<------>struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
<------>LIST_HEAD(head);
 
<------>do {
<------><------>list_splice_init(&mirror->pg_list, &head);
<------><------>mirror->pg_count = 0;
<------><------>mirror->pg_base = 0;
<------><------>mirror->pg_recoalesce = 0;
 
<------><------>while (!list_empty(&head)) {
<------><------><------>struct nfs_page *req;
 
<------><------><------>req = list_first_entry(&head, struct nfs_page, wb_list);
<------><------><------>if (__nfs_pageio_add_request(desc, req))
<------><------><------><------>continue;
<------><------><------>if (desc->pg_error < 0) {
<------><------><------><------>list_splice_tail(&head, &mirror->pg_list);
<------><------><------><------>mirror->pg_recoalesce = 1;
<------><------><------><------>return 0;
<------><------><------>}
<------><------><------>break;
<------><------>}
<------>} while (mirror->pg_recoalesce);
<------>return 1;
}
 
static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
<------><------>struct nfs_page *req)
{
<------>int ret;
 
<------>do {
<------><------>ret = __nfs_pageio_add_request(desc, req);
<------><------>if (ret)
<------><------><------>break;
<------><------>if (desc->pg_error < 0)
<------><------><------>break;
<------><------>ret = nfs_do_recoalesce(desc);
<------>} while (ret);
 
<------>return ret;
}
 
static void nfs_pageio_error_cleanup(struct nfs_pageio_descriptor *desc)
{
<------>u32 midx;
<------>struct nfs_pgio_mirror *mirror;
 
<------>if (!desc->pg_error)
<------><------>return;
 
<------>for (midx = 0; midx < desc->pg_mirror_count; midx++) {
<------><------>mirror = nfs_pgio_get_mirror(desc, midx);
<------><------>desc->pg_completion_ops->error_cleanup(&mirror->pg_list,
<------><------><------><------>desc->pg_error);
<------>}
}
 
int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
<------><------><------>   struct nfs_page *req)
{
<------>u32 midx;
<------>unsigned int pgbase, offset, bytes;
<------>struct nfs_page *dupreq;
 
<------>pgbase = req->wb_pgbase;
<------>offset = req->wb_offset;
<------>bytes = req->wb_bytes;
 
<------>nfs_pageio_setup_mirroring(desc, req);
<------>if (desc->pg_error < 0)
<------><------>goto out_failed;
 
<------>/* Create the mirror instances first, and fire them off */
<------>for (midx = 1; midx < desc->pg_mirror_count; midx++) {
<------><------>nfs_page_group_lock(req);
 
<------><------>dupreq = nfs_create_subreq(req,
<------><------><------><------>pgbase, offset, bytes);
 
<------><------>nfs_page_group_unlock(req);
<------><------>if (IS_ERR(dupreq)) {
<------><------><------>desc->pg_error = PTR_ERR(dupreq);
<------><------><------>goto out_failed;
<------><------>}
 
<------><------>nfs_pgio_set_current_mirror(desc, midx);
<------><------>if (!nfs_pageio_add_request_mirror(desc, dupreq))
<------><------><------>goto out_cleanup_subreq;
<------>}
 
<------>nfs_pgio_set_current_mirror(desc, 0);
<------>if (!nfs_pageio_add_request_mirror(desc, req))
<------><------>goto out_failed;
 
<------>return 1;
 
out_cleanup_subreq:
<------>nfs_pageio_cleanup_request(desc, dupreq);
out_failed:
<------>nfs_pageio_error_cleanup(desc);
<------>return 0;
}
 
/*
 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
 *				nfs_pageio_descriptor
 * @desc: pointer to io descriptor
 * @mirror_idx: pointer to mirror index
 */
static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
<------><------><------><------>       u32 mirror_idx)
{
<------>struct nfs_pgio_mirror *mirror;
<------>u32 restore_idx;
 
<------>restore_idx = nfs_pgio_set_current_mirror(desc, mirror_idx);
<------>mirror = nfs_pgio_current_mirror(desc);
 
<------>for (;;) {
<------><------>nfs_pageio_doio(desc);
<------><------>if (desc->pg_error < 0 || !mirror->pg_recoalesce)
<------><------><------>break;
<------><------>if (!nfs_do_recoalesce(desc))
<------><------><------>break;
<------>}
<------>nfs_pgio_set_current_mirror(desc, restore_idx);
}
 
/*
 * nfs_pageio_resend - Transfer requests to new descriptor and resend
 * @hdr - the pgio header to move request from
 * @desc - the pageio descriptor to add requests to
 *
 * Try to move each request (nfs_page) from @hdr to @desc then attempt
 * to send them.
 *
 * Returns 0 on success and < 0 on error.
 */
int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
<------><------>      struct nfs_pgio_header *hdr)
{
<------>LIST_HEAD(pages);
 
<------>desc->pg_io_completion = hdr->io_completion;
<------>desc->pg_dreq = hdr->dreq;
<------>list_splice_init(&hdr->pages, &pages);
<------>while (!list_empty(&pages)) {
<------><------>struct nfs_page *req = nfs_list_entry(pages.next);
 
<------><------>if (!nfs_pageio_add_request(desc, req))
<------><------><------>break;
<------>}
<------>nfs_pageio_complete(desc);
<------>if (!list_empty(&pages)) {
<------><------>int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
<------><------>hdr->completion_ops->error_cleanup(&pages, err);
<------><------>nfs_set_pgio_error(hdr, err, hdr->io_start);
<------><------>return err;
<------>}
<------>return 0;
}
EXPORT_SYMBOL_GPL(nfs_pageio_resend);
 
/**
 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
 * @desc: pointer to io descriptor
 */
void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
{
<------>u32 midx;
 
<------>for (midx = 0; midx < desc->pg_mirror_count; midx++)
<------><------>nfs_pageio_complete_mirror(desc, midx);
 
<------>if (desc->pg_error < 0)
<------><------>nfs_pageio_error_cleanup(desc);
<------>if (desc->pg_ops->pg_cleanup)
<------><------>desc->pg_ops->pg_cleanup(desc);
<------>nfs_pageio_cleanup_mirroring(desc);
}
 
/**
 * nfs_pageio_cond_complete - Conditional I/O completion
 * @desc: pointer to io descriptor
 * @index: page index
 *
 * It is important to ensure that processes don't try to take locks
 * on non-contiguous ranges of pages as that might deadlock. This
 * function should be called before attempting to wait on a locked
 * nfs_page. It will complete the I/O if the page index 'index'
 * is not contiguous with the existing list of pages in 'desc'.
 */
void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
{
<------>struct nfs_pgio_mirror *mirror;
<------>struct nfs_page *prev;
<------>u32 midx;
 
<------>for (midx = 0; midx < desc->pg_mirror_count; midx++) {
<------><------>mirror = nfs_pgio_get_mirror(desc, midx);
<------><------>if (!list_empty(&mirror->pg_list)) {
<------><------><------>prev = nfs_list_entry(mirror->pg_list.prev);
<------><------><------>if (index != prev->wb_index + 1) {
<------><------><------><------>nfs_pageio_complete(desc);
<------><------><------><------>break;
<------><------><------>}
<------><------>}
<------>}
}
 
/*
 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
 */
void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
{
<------>nfs_pageio_complete(pgio);
}
 
int __init nfs_init_nfspagecache(void)
{
<------>nfs_page_cachep = kmem_cache_create("nfs_page",
<------><------><------><------><------>    sizeof(struct nfs_page),
<------><------><------><------><------>    0, SLAB_HWCACHE_ALIGN,
<------><------><------><------><------>    NULL);
<------>if (nfs_page_cachep == NULL)
<------><------>return -ENOMEM;
 
<------>return 0;
}
 
void nfs_destroy_nfspagecache(void)
{
<------>kmem_cache_destroy(nfs_page_cachep);
}
 
static const struct rpc_call_ops nfs_pgio_common_ops = {
<------>.rpc_call_prepare = nfs_pgio_prepare,
<------>.rpc_call_done = nfs_pgio_result,
<------>.rpc_release = nfs_pgio_release,
};
 
const struct nfs_pageio_ops nfs_pgio_rw_ops = {
<------>.pg_test = nfs_generic_pg_test,
<------>.pg_doio = nfs_generic_pg_pgios,
};