write.c 57.8 KB
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// SPDX-License-Identifier: GPL-2.0-only
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/*
 * linux/fs/nfs/write.c
 *
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 * Write file data over NFS.
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 *
 * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/writeback.h>
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#include <linux/swap.h>
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#include <linux/migrate.h>
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#include <linux/sunrpc/clnt.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/nfs_page.h>
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#include <linux/backing-dev.h>
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#include <linux/export.h>
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#include <linux/freezer.h>
#include <linux/wait.h>
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#include <linux/iversion.h>
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#include <linux/uaccess.h>
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#include <linux/sched/mm.h>
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#include "delegation.h"
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#include "internal.h"
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#include "iostat.h"
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#include "nfs4_fs.h"
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#include "fscache.h"
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#include "pnfs.h"
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#include "nfstrace.h"

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#define NFSDBG_FACILITY		NFSDBG_PAGECACHE

#define MIN_POOL_WRITE		(32)
#define MIN_POOL_COMMIT		(4)

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struct nfs_io_completion {
	void (*complete)(void *data);
	void *data;
	struct kref refcount;
};

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/*
 * Local function declarations
 */
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static void nfs_redirty_request(struct nfs_page *req);
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static const struct rpc_call_ops nfs_commit_ops;
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static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
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static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
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static const struct nfs_rw_ops nfs_rw_write_ops;
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static void nfs_inode_remove_request(struct nfs_page *req);
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static void nfs_clear_request_commit(struct nfs_page *req);
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static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
				      struct inode *inode);
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static struct nfs_page *
nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
						struct page *page);
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static struct kmem_cache *nfs_wdata_cachep;
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static mempool_t *nfs_wdata_mempool;
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static struct kmem_cache *nfs_cdata_cachep;
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static mempool_t *nfs_commit_mempool;

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struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail)
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{
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	struct nfs_commit_data *p;
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	if (never_fail)
		p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
	else {
		/* It is OK to do some reclaim, not no safe to wait
		 * for anything to be returned to the pool.
		 * mempool_alloc() cannot handle that particular combination,
		 * so we need two separate attempts.
		 */
		p = mempool_alloc(nfs_commit_mempool, GFP_NOWAIT);
		if (!p)
			p = kmem_cache_alloc(nfs_cdata_cachep, GFP_NOIO |
					     __GFP_NOWARN | __GFP_NORETRY);
		if (!p)
			return NULL;
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	}
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	memset(p, 0, sizeof(*p));
	INIT_LIST_HEAD(&p->pages);
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	return p;
}
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EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
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void nfs_commit_free(struct nfs_commit_data *p)
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{
	mempool_free(p, nfs_commit_mempool);
}
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EXPORT_SYMBOL_GPL(nfs_commit_free);
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static struct nfs_pgio_header *nfs_writehdr_alloc(void)
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{
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	struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_KERNEL);
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	memset(p, 0, sizeof(*p));
	p->rw_mode = FMODE_WRITE;
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	return p;
}
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static void nfs_writehdr_free(struct nfs_pgio_header *hdr)
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{
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	mempool_free(hdr, nfs_wdata_mempool);
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}
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static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags)
{
	return kmalloc(sizeof(struct nfs_io_completion), gfp_flags);
}

static void nfs_io_completion_init(struct nfs_io_completion *ioc,
		void (*complete)(void *), void *data)
{
	ioc->complete = complete;
	ioc->data = data;
	kref_init(&ioc->refcount);
}

static void nfs_io_completion_release(struct kref *kref)
{
	struct nfs_io_completion *ioc = container_of(kref,
			struct nfs_io_completion, refcount);
	ioc->complete(ioc->data);
	kfree(ioc);
}

static void nfs_io_completion_get(struct nfs_io_completion *ioc)
{
	if (ioc != NULL)
		kref_get(&ioc->refcount);
}

static void nfs_io_completion_put(struct nfs_io_completion *ioc)
{
	if (ioc != NULL)
		kref_put(&ioc->refcount, nfs_io_completion_release);
}

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static struct nfs_page *
nfs_page_private_request(struct page *page)
{
	if (!PagePrivate(page))
		return NULL;
	return (struct nfs_page *)page_private(page);
}

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/*
 * nfs_page_find_head_request_locked - find head request associated with @page
 *
 * must be called while holding the inode lock.
 *
 * returns matching head request with reference held, or NULL if not found.
 */
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static struct nfs_page *
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nfs_page_find_private_request(struct page *page)
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{
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	struct address_space *mapping = page_file_mapping(page);
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	struct nfs_page *req;
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	if (!PagePrivate(page))
		return NULL;
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	spin_lock(&mapping->private_lock);
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	req = nfs_page_private_request(page);
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	if (req) {
		WARN_ON_ONCE(req->wb_head != req);
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		kref_get(&req->wb_kref);
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	}
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	spin_unlock(&mapping->private_lock);
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	return req;
}
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static struct nfs_page *
nfs_page_find_swap_request(struct page *page)
{
	struct inode *inode = page_file_mapping(page)->host;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_page *req = NULL;
	if (!PageSwapCache(page))
		return NULL;
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	mutex_lock(&nfsi->commit_mutex);
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	if (PageSwapCache(page)) {
		req = nfs_page_search_commits_for_head_request_locked(nfsi,
			page);
		if (req) {
			WARN_ON_ONCE(req->wb_head != req);
			kref_get(&req->wb_kref);
		}
	}
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	mutex_unlock(&nfsi->commit_mutex);
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	return req;
}

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/*
 * nfs_page_find_head_request - find head request associated with @page
 *
 * returns matching head request with reference held, or NULL if not found.
 */
static struct nfs_page *nfs_page_find_head_request(struct page *page)
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{
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	struct nfs_page *req;
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	req = nfs_page_find_private_request(page);
	if (!req)
		req = nfs_page_find_swap_request(page);
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	return req;
}

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/* Adjust the file length if we're writing beyond the end */
static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
{
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	struct inode *inode = page_file_mapping(page)->host;
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	loff_t end, i_size;
	pgoff_t end_index;
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	spin_lock(&inode->i_lock);
	i_size = i_size_read(inode);
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	end_index = (i_size - 1) >> PAGE_SHIFT;
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	if (i_size > 0 && page_index(page) < end_index)
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		goto out;
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	end = page_file_offset(page) + ((loff_t)offset+count);
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	if (i_size >= end)
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		goto out;
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	i_size_write(inode, end);
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	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
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	nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
out:
	spin_unlock(&inode->i_lock);
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}

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/* A writeback failed: mark the page as bad, and invalidate the page cache */
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static void nfs_set_pageerror(struct address_space *mapping)
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{
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	struct inode *inode = mapping->host;

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	nfs_zap_mapping(mapping->host, mapping);
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	/* Force file size revalidation */
	spin_lock(&inode->i_lock);
	NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED |
					NFS_INO_REVAL_PAGECACHE |
					NFS_INO_INVALID_SIZE;
	spin_unlock(&inode->i_lock);
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}

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static void nfs_mapping_set_error(struct page *page, int error)
{
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	struct address_space *mapping = page_file_mapping(page);

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	SetPageError(page);
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	mapping_set_error(mapping, error);
	nfs_set_pageerror(mapping);
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}

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/*
 * nfs_page_group_search_locked
 * @head - head request of page group
 * @page_offset - offset into page
 *
 * Search page group with head @head to find a request that contains the
 * page offset @page_offset.
 *
 * Returns a pointer to the first matching nfs request, or NULL if no
 * match is found.
 *
 * Must be called with the page group lock held
 */
static struct nfs_page *
nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
{
	struct nfs_page *req;

	req = head;
	do {
		if (page_offset >= req->wb_pgbase &&
		    page_offset < (req->wb_pgbase + req->wb_bytes))
			return req;

		req = req->wb_this_page;
	} while (req != head);

	return NULL;
}

/*
 * nfs_page_group_covers_page
 * @head - head request of page group
 *
 * Return true if the page group with head @head covers the whole page,
 * returns false otherwise
 */
static bool nfs_page_group_covers_page(struct nfs_page *req)
{
	struct nfs_page *tmp;
	unsigned int pos = 0;
	unsigned int len = nfs_page_length(req->wb_page);

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	nfs_page_group_lock(req);
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	for (;;) {
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		tmp = nfs_page_group_search_locked(req->wb_head, pos);
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		if (!tmp)
			break;
		pos = tmp->wb_pgbase + tmp->wb_bytes;
	}
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	nfs_page_group_unlock(req);
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	return pos >= len;
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}

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/* We can set the PG_uptodate flag if we see that a write request
 * covers the full page.
 */
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static void nfs_mark_uptodate(struct nfs_page *req)
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{
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	if (PageUptodate(req->wb_page))
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		return;
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	if (!nfs_page_group_covers_page(req))
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		return;
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	SetPageUptodate(req->wb_page);
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}

static int wb_priority(struct writeback_control *wbc)
{
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	int ret = 0;
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	if (wbc->sync_mode == WB_SYNC_ALL)
		ret = FLUSH_COND_STABLE;
	return ret;
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}

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/*
 * NFS congestion control
 */

int nfs_congestion_kb;

#define NFS_CONGESTION_ON_THRESH 	(nfs_congestion_kb >> (PAGE_SHIFT-10))
#define NFS_CONGESTION_OFF_THRESH	\
	(NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))

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static void nfs_set_page_writeback(struct page *page)
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{
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	struct inode *inode = page_file_mapping(page)->host;
	struct nfs_server *nfss = NFS_SERVER(inode);
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	int ret = test_set_page_writeback(page);

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	WARN_ON_ONCE(ret != 0);
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	if (atomic_long_inc_return(&nfss->writeback) >
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			NFS_CONGESTION_ON_THRESH)
		set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
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}

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static void nfs_end_page_writeback(struct nfs_page *req)
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{
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	struct inode *inode = page_file_mapping(req->wb_page)->host;
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	struct nfs_server *nfss = NFS_SERVER(inode);
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	bool is_done;
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	is_done = nfs_page_group_sync_on_bit(req, PG_WB_END);
	nfs_unlock_request(req);
	if (!is_done)
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		return;

	end_page_writeback(req->wb_page);
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	if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
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		clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
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}

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/*
 * nfs_unroll_locks_and_wait -  unlock all newly locked reqs and wait on @req
 *
 * this is a helper function for nfs_lock_and_join_requests
 *
 * @inode - inode associated with request page group, must be holding inode lock
 * @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
 *
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 * NOTE: this must be called holding page_group bit lock
 *       which will be released before returning.
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 *
 * returns 0 on success, < 0 on error.
 */
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static void
nfs_unroll_locks(struct inode *inode, struct nfs_page *head,
398
			  struct nfs_page *req)
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{
	struct nfs_page *tmp;

	/* relinquish all the locks successfully grabbed this run */
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	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);
	}
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}

/*
 * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests
 *
 * @destroy_list - request list (using wb_this_page) terminated by @old_head
 * @old_head - the old head of the list
 *
 * All subrequests must be locked and removed from all lists, so at this point
 * they are only "active" in this function, and possibly in nfs_wait_on_request
 * with a reference held by some other context.
 */
static void
nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
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				 struct nfs_page *old_head,
				 struct inode *inode)
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{
	while (destroy_list) {
		struct nfs_page *subreq = destroy_list;

		destroy_list = (subreq->wb_this_page == old_head) ?
				   NULL : subreq->wb_this_page;

		WARN_ON_ONCE(old_head != subreq->wb_head);

		/* make sure old group is not used */
		subreq->wb_this_page = subreq;

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		clear_bit(PG_REMOVE, &subreq->wb_flags);

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		/* Note: races with nfs_page_group_destroy() */
		if (!kref_read(&subreq->wb_kref)) {
			/* Check if we raced with nfs_page_group_destroy() */
441
			if (test_and_clear_bit(PG_TEARDOWN, &subreq->wb_flags))
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				nfs_free_request(subreq);
			continue;
		}
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		subreq->wb_head = subreq;

		if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) {
			nfs_release_request(subreq);
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			atomic_long_dec(&NFS_I(inode)->nrequests);
451
		}
452 453 454 455

		/* subreq is now totally disconnected from page group or any
		 * write / commit lists. last chance to wake any waiters */
		nfs_unlock_and_release_request(subreq);
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	}
}

/*
 * nfs_lock_and_join_requests - join all subreqs to the head req and return
 *                              a locked reference, cancelling any pending
 *                              operations for this page.
 *
 * @page - the page used to lookup the "page group" of nfs_page structures
 *
 * This function joins all sub requests to the head request by first
 * locking all requests in the group, cancelling any pending operations
 * and finally updating the head request to cover the whole range covered by
 * the (former) group.  All subrequests are removed from any write or commit
 * lists, unlinked from the group and destroyed.
 *
 * Returns a locked, referenced pointer to the head request - which after
 * this call is guaranteed to be the only request associated with the page.
 * Returns NULL if no requests are found for @page, or a ERR_PTR if an
 * error was encountered.
 */
static struct nfs_page *
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nfs_lock_and_join_requests(struct page *page)
479
{
480
	struct inode *inode = page_file_mapping(page)->host;
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	struct nfs_page *head, *subreq;
	struct nfs_page *destroy_list = NULL;
	unsigned int total_bytes;
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	int ret;

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try_again:
	/*
	 * A reference is taken only on the head request which acts as a
	 * reference to the whole page group - the group will not be destroyed
	 * until the head reference is released.
	 */
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	head = nfs_page_find_head_request(page);
	if (!head)
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		return NULL;

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	/* lock the page head first in order to avoid an ABBA inefficiency */
	if (!nfs_lock_request(head)) {
		ret = nfs_wait_on_request(head);
		nfs_release_request(head);
		if (ret < 0)
			return ERR_PTR(ret);
		goto try_again;
	}
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	/* Ensure that nobody removed the request before we locked it */
	if (head != nfs_page_private_request(page) && !PageSwapCache(page)) {
		nfs_unlock_and_release_request(head);
		goto try_again;
	}
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511
	ret = nfs_page_group_lock(head);
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	if (ret < 0)
		goto release_request;
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	/* lock each request in the page group */
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	total_bytes = head->wb_bytes;
	for (subreq = head->wb_this_page; subreq != head;
			subreq = subreq->wb_this_page) {
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		if (!kref_get_unless_zero(&subreq->wb_kref)) {
			if (subreq->wb_offset == head->wb_offset + total_bytes)
				total_bytes += subreq->wb_bytes;
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			continue;
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		}

526
		while (!nfs_lock_request(subreq)) {
527
			/*
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			 * Unlock page to allow nfs_page_group_sync_on_bit()
			 * to succeed
530
			 */
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			nfs_page_group_unlock(head);
			ret = nfs_wait_on_request(subreq);
			if (!ret)
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				ret = nfs_page_group_lock(head);
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			if (ret < 0) {
				nfs_unroll_locks(inode, head, subreq);
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				nfs_release_request(subreq);
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				goto release_request;
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			}
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		}
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		/*
		 * Subrequests are always contiguous, non overlapping
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		 * and in order - but may be repeated (mirrored writes).
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		 */
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		if (subreq->wb_offset == (head->wb_offset + total_bytes)) {
			/* keep track of how many bytes this group covers */
			total_bytes += subreq->wb_bytes;
		} else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset ||
			    ((subreq->wb_offset + subreq->wb_bytes) >
			     (head->wb_offset + total_bytes)))) {
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			nfs_page_group_unlock(head);
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			nfs_unroll_locks(inode, head, subreq);
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			nfs_unlock_and_release_request(subreq);
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			ret = -EIO;
			goto release_request;
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		}
557
	}
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	/* Now that all requests are locked, make sure they aren't on any list.
	 * Commit list removal accounting is done after locks are dropped */
	subreq = head;
	do {
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		nfs_clear_request_commit(subreq);
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		subreq = subreq->wb_this_page;
	} while (subreq != head);

	/* unlink subrequests from head, destroy them later */
	if (head->wb_this_page != head) {
		/* destroy list will be terminated by head */
		destroy_list = head->wb_this_page;
		head->wb_this_page = head;

		/* change head request to cover whole range that
		 * the former page group covered */
		head->wb_bytes = total_bytes;
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	}
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	/* Postpone destruction of this request */
	if (test_and_clear_bit(PG_REMOVE, &head->wb_flags)) {
		set_bit(PG_INODE_REF, &head->wb_flags);
		kref_get(&head->wb_kref);
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		atomic_long_inc(&NFS_I(inode)->nrequests);
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	}

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	nfs_page_group_unlock(head);

587
	nfs_destroy_unlinked_subrequests(destroy_list, head, inode);
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	/* Did we lose a race with nfs_inode_remove_request()? */
	if (!(PagePrivate(page) || PageSwapCache(page))) {
		nfs_unlock_and_release_request(head);
		return NULL;
	}

595
	/* still holds ref on head from nfs_page_find_head_request
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	 * and still has lock on head from lock loop */
	return head;
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release_request:
	nfs_unlock_and_release_request(head);
	return ERR_PTR(ret);
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}

604
static void nfs_write_error(struct nfs_page *req, int error)
605
{
606
	trace_nfs_write_error(req, error);
607
	nfs_mapping_set_error(req->wb_page, error);
608
	nfs_inode_remove_request(req);
609
	nfs_end_page_writeback(req);
610
	nfs_release_request(req);
611 612
}

613 614 615 616 617
/*
 * Find an associated nfs write request, and prepare to flush it out
 * May return an error if the user signalled nfs_wait_on_request().
 */
static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
618
				struct page *page)
619 620 621 622
{
	struct nfs_page *req;
	int ret = 0;

623
	req = nfs_lock_and_join_requests(page);
624 625 626 627 628 629
	if (!req)
		goto out;
	ret = PTR_ERR(req);
	if (IS_ERR(req))
		goto out;

630 631
	nfs_set_page_writeback(page);
	WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
632

633
	/* If there is a fatal error that covers this write, just exit */
634 635
	ret = pgio->pg_error;
	if (nfs_error_is_fatal_on_server(ret))
636 637
		goto out_launder;

638
	ret = 0;
639
	if (!nfs_pageio_add_request(pgio, req)) {
640
		ret = pgio->pg_error;
641
		/*
642
		 * Remove the problematic req upon fatal errors on the server
643 644
		 */
		if (nfs_error_is_fatal(ret)) {
645
			if (nfs_error_is_fatal_on_server(ret))
646
				goto out_launder;
647 648
		} else
			ret = -EAGAIN;
649
		nfs_redirty_request(req);
650
		pgio->pg_error = 0;
651 652 653
	} else
		nfs_add_stats(page_file_mapping(page)->host,
				NFSIOS_WRITEPAGES, 1);
654 655
out:
	return ret;
656
out_launder:
657
	nfs_write_error(req, ret);
658
	return 0;
659 660
}

661
static int nfs_do_writepage(struct page *page, struct writeback_control *wbc,
662
			    struct nfs_pageio_descriptor *pgio)
L
Linus Torvalds 已提交
663
{
664
	int ret;
L
Linus Torvalds 已提交
665

H
Huang Ying 已提交
666
	nfs_pageio_cond_complete(pgio, page_index(page));
667
	ret = nfs_page_async_flush(pgio, page);
668 669
	if (ret == -EAGAIN) {
		redirty_page_for_writepage(wbc, page);
670
		ret = AOP_WRITEPAGE_ACTIVATE;
671 672
	}
	return ret;
673
}
674

675 676 677
/*
 * Write an mmapped page to the server.
 */
678
static int nfs_writepage_locked(struct page *page,
679
				struct writeback_control *wbc)
680 681
{
	struct nfs_pageio_descriptor pgio;
682
	struct inode *inode = page_file_mapping(page)->host;
683
	int err;
684

685
	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
686
	nfs_pageio_init_write(&pgio, inode, 0,
687
				false, &nfs_async_write_completion_ops);
688
	err = nfs_do_writepage(page, wbc, &pgio);
689
	pgio.pg_error = 0;
690 691 692
	nfs_pageio_complete(&pgio);
	if (err < 0)
		return err;
693
	if (nfs_error_is_fatal(pgio.pg_error))
694 695
		return pgio.pg_error;
	return 0;
696 697 698 699
}

int nfs_writepage(struct page *page, struct writeback_control *wbc)
{
700
	int ret;
701

702
	ret = nfs_writepage_locked(page, wbc);
703 704
	if (ret != AOP_WRITEPAGE_ACTIVATE)
		unlock_page(page);
705 706 707 708 709 710 711
	return ret;
}

static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
{
	int ret;

712
	ret = nfs_do_writepage(page, wbc, data);
713 714
	if (ret != AOP_WRITEPAGE_ACTIVATE)
		unlock_page(page);
715
	return ret;
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Linus Torvalds 已提交
716 717
}

718 719 720 721 722
static void nfs_io_completion_commit(void *inode)
{
	nfs_commit_inode(inode, 0);
}

L
Linus Torvalds 已提交
723 724 725
int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
	struct inode *inode = mapping->host;
726
	struct nfs_pageio_descriptor pgio;
727
	struct nfs_io_completion *ioc;
L
Linus Torvalds 已提交
728 729
	int err;

730 731
	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);

732
	ioc = nfs_io_completion_alloc(GFP_KERNEL);
733 734 735
	if (ioc)
		nfs_io_completion_init(ioc, nfs_io_completion_commit, inode);

736 737
	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false,
				&nfs_async_write_completion_ops);
738
	pgio.pg_io_completion = ioc;
739
	err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
740
	pgio.pg_error = 0;
741
	nfs_pageio_complete(&pgio);
742
	nfs_io_completion_put(ioc);
743

744
	if (err < 0)
745 746
		goto out_err;
	err = pgio.pg_error;
747
	if (nfs_error_is_fatal(err))
748
		goto out_err;
749
	return 0;
750 751
out_err:
	return err;
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752 753 754 755 756
}

/*
 * Insert a write request into an inode
 */
757
static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
L
Linus Torvalds 已提交
758
{
759
	struct address_space *mapping = page_file_mapping(req->wb_page);
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760
	struct nfs_inode *nfsi = NFS_I(inode);
761

762 763
	WARN_ON_ONCE(req->wb_this_page != req);

764
	/* Lock the request! */
765
	nfs_lock_request(req);
766

767 768 769 770
	/*
	 * Swap-space should not get truncated. Hence no need to plug the race
	 * with invalidate/truncate.
	 */
771 772
	spin_lock(&mapping->private_lock);
	if (!nfs_have_writebacks(inode) &&
773 774
	    NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
		inode_inc_iversion_raw(inode);
775 776 777 778 779
	if (likely(!PageSwapCache(req->wb_page))) {
		set_bit(PG_MAPPED, &req->wb_flags);
		SetPagePrivate(req->wb_page);
		set_page_private(req->wb_page, (unsigned long)req);
	}
780
	spin_unlock(&mapping->private_lock);
781
	atomic_long_inc(&nfsi->nrequests);
782
	/* this a head request for a page group - mark it as having an
783 784 785
	 * extra reference so sub groups can follow suit.
	 * This flag also informs pgio layer when to bump nrequests when
	 * adding subrequests. */
786
	WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
787
	kref_get(&req->wb_kref);
L
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788 789 790
}

/*
791
 * Remove a write request from an inode
L
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792 793 794
 */
static void nfs_inode_remove_request(struct nfs_page *req)
{
795 796
	struct address_space *mapping = page_file_mapping(req->wb_page);
	struct inode *inode = mapping->host;
L
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797
	struct nfs_inode *nfsi = NFS_I(inode);
798
	struct nfs_page *head;
L
Linus Torvalds 已提交
799

800 801 802
	if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
		head = req->wb_head;

803
		spin_lock(&mapping->private_lock);
804
		if (likely(head->wb_page && !PageSwapCache(head->wb_page))) {
805 806 807 808
			set_page_private(head->wb_page, 0);
			ClearPagePrivate(head->wb_page);
			clear_bit(PG_MAPPED, &head->wb_flags);
		}
809
		spin_unlock(&mapping->private_lock);
810
	}
811

812
	if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) {
813
		nfs_release_request(req);
814 815
		atomic_long_dec(&nfsi->nrequests);
	}
L
Linus Torvalds 已提交
816 817
}

818
static void
F
Fred 已提交
819
nfs_mark_request_dirty(struct nfs_page *req)
820
{
821 822
	if (req->wb_page)
		__set_page_dirty_nobuffers(req->wb_page);
823 824
}

825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856
/*
 * nfs_page_search_commits_for_head_request_locked
 *
 * Search through commit lists on @inode for the head request for @page.
 * Must be called while holding the inode (which is cinfo) lock.
 *
 * Returns the head request if found, or NULL if not found.
 */
static struct nfs_page *
nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
						struct page *page)
{
	struct nfs_page *freq, *t;
	struct nfs_commit_info cinfo;
	struct inode *inode = &nfsi->vfs_inode;

	nfs_init_cinfo_from_inode(&cinfo, inode);

	/* search through pnfs commit lists */
	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
	if (freq)
		return freq->wb_head;

	/* Linearly search the commit list for the correct request */
	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
		if (freq->wb_page == page)
			return freq->wb_head;
	}

	return NULL;
}

857 858 859 860 861 862 863 864 865 866
/**
 * nfs_request_add_commit_list_locked - add request to a commit list
 * @req: pointer to a struct nfs_page
 * @dst: commit list head
 * @cinfo: holds list lock and accounting info
 *
 * This sets the PG_CLEAN bit, updates the cinfo count of
 * number of outstanding requests requiring a commit as well as
 * the MM page stats.
 *
867 868
 * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the
 * nfs_page lock.
869 870 871 872 873 874 875
 */
void
nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
			    struct nfs_commit_info *cinfo)
{
	set_bit(PG_CLEAN, &req->wb_flags);
	nfs_list_add_request(req, dst);
876
	atomic_long_inc(&cinfo->mds->ncommit);
877 878 879
}
EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);

880 881 882
/**
 * nfs_request_add_commit_list - add request to a commit list
 * @req: pointer to a struct nfs_page
883
 * @cinfo: holds list lock and accounting info
884
 *
885
 * This sets the PG_CLEAN bit, updates the cinfo count of
886 887 888
 * number of outstanding requests requiring a commit as well as
 * the MM page stats.
 *
889
 * The caller must _not_ hold the cinfo->lock, but must be
890
 * holding the nfs_page lock.
L
Linus Torvalds 已提交
891
 */
892
void
893
nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)
L
Linus Torvalds 已提交
894
{
895
	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
896
	nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);
897
	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
898 899
	if (req->wb_page)
		nfs_mark_page_unstable(req->wb_page, cinfo);
L
Linus Torvalds 已提交
900
}
901 902 903 904 905
EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);

/**
 * nfs_request_remove_commit_list - Remove request from a commit list
 * @req: pointer to a nfs_page
906
 * @cinfo: holds list lock and accounting info
907
 *
908
 * This clears the PG_CLEAN bit, and updates the cinfo's count of
909 910 911
 * number of outstanding requests requiring a commit
 * It does not update the MM page stats.
 *
912
 * The caller _must_ hold the cinfo->lock and the nfs_page lock.
913 914
 */
void
915 916
nfs_request_remove_commit_list(struct nfs_page *req,
			       struct nfs_commit_info *cinfo)
917 918 919 920
{
	if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
		return;
	nfs_list_remove_request(req);
921
	atomic_long_dec(&cinfo->mds->ncommit);
922 923 924
}
EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);

925 926 927
static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
				      struct inode *inode)
{
928
	cinfo->inode = inode;
929 930
	cinfo->mds = &NFS_I(inode)->commit_info;
	cinfo->ds = pnfs_get_ds_info(inode);
931
	cinfo->dreq = NULL;
932
	cinfo->completion_ops = &nfs_commit_completion_ops;
933 934 935 936 937 938
}

void nfs_init_cinfo(struct nfs_commit_info *cinfo,
		    struct inode *inode,
		    struct nfs_direct_req *dreq)
{
939 940 941 942
	if (dreq)
		nfs_init_cinfo_from_dreq(cinfo, dreq);
	else
		nfs_init_cinfo_from_inode(cinfo, inode);
943 944
}
EXPORT_SYMBOL_GPL(nfs_init_cinfo);
945 946 947 948

/*
 * Add a request to the inode's commit list.
 */
949
void
950
nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
951
			struct nfs_commit_info *cinfo, u32 ds_commit_idx)
952
{
953
	if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx))
954
		return;
955
	nfs_request_add_commit_list(req, cinfo);
956
}
957

958 959 960
static void
nfs_clear_page_commit(struct page *page)
{
961
	dec_node_page_state(page, NR_UNSTABLE_NFS);
962 963
	dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb,
		    WB_RECLAIMABLE);
964 965
}

966
/* Called holding the request lock on @req */
967
static void
968 969
nfs_clear_request_commit(struct nfs_page *req)
{
970
	if (test_bit(PG_CLEAN, &req->wb_flags)) {
971 972
		struct nfs_open_context *ctx = nfs_req_openctx(req);
		struct inode *inode = d_inode(ctx->dentry);
973
		struct nfs_commit_info cinfo;
974

975
		nfs_init_cinfo_from_inode(&cinfo, inode);
976
		mutex_lock(&NFS_I(inode)->commit_mutex);
977 978
		if (!pnfs_clear_request_commit(req, &cinfo)) {
			nfs_request_remove_commit_list(req, &cinfo);
979
		}
980
		mutex_unlock(&NFS_I(inode)->commit_mutex);
981
		nfs_clear_page_commit(req->wb_page);
982 983 984
	}
}

985
int nfs_write_need_commit(struct nfs_pgio_header *hdr)
986
{
987
	if (hdr->verf.committed == NFS_DATA_SYNC)
988
		return hdr->lseg == NULL;
989
	return hdr->verf.committed != NFS_FILE_SYNC;
990 991
}

992 993 994 995 996
static void nfs_async_write_init(struct nfs_pgio_header *hdr)
{
	nfs_io_completion_get(hdr->io_completion);
}

997
static void nfs_write_completion(struct nfs_pgio_header *hdr)
998
{
999
	struct nfs_commit_info cinfo;
1000 1001 1002 1003
	unsigned long bytes = 0;

	if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
		goto out;
1004
	nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
1005 1006 1007 1008 1009 1010 1011
	while (!list_empty(&hdr->pages)) {
		struct nfs_page *req = nfs_list_entry(hdr->pages.next);

		bytes += req->wb_bytes;
		nfs_list_remove_request(req);
		if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
		    (hdr->good_bytes < bytes)) {
1012
			trace_nfs_comp_error(req, hdr->error);
1013
			nfs_mapping_set_error(req->wb_page, hdr->error);
1014 1015
			goto remove_req;
		}
1016
		if (nfs_write_need_commit(hdr)) {
1017 1018
			/* Reset wb_nio, since the write was successful. */
			req->wb_nio = 0;
1019
			memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
1020
			nfs_mark_request_commit(req, hdr->lseg, &cinfo,
1021
				hdr->pgio_mirror_idx);
1022 1023 1024 1025 1026
			goto next;
		}
remove_req:
		nfs_inode_remove_request(req);
next:
1027
		nfs_end_page_writeback(req);
1028
		nfs_release_request(req);
1029 1030
	}
out:
1031
	nfs_io_completion_put(hdr->io_completion);
1032
	hdr->release(hdr);
1033
}
L
Linus Torvalds 已提交
1034

1035
unsigned long
1036
nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
1037
{
1038
	return atomic_long_read(&cinfo->mds->ncommit);
1039 1040
}

1041
/* NFS_I(cinfo->inode)->commit_mutex held by caller */
1042
int
1043 1044
nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
		     struct nfs_commit_info *cinfo, int max)
1045
{
1046
	struct nfs_page *req, *tmp;
1047 1048
	int ret = 0;

1049 1050
restart:
	list_for_each_entry_safe(req, tmp, src, wb_list) {
1051
		kref_get(&req->wb_kref);
1052 1053
		if (!nfs_lock_request(req)) {
			int status;
1054 1055 1056 1057 1058 1059 1060

			/* Prevent deadlock with nfs_lock_and_join_requests */
			if (!list_empty(dst)) {
				nfs_release_request(req);
				continue;
			}
			/* Ensure we make progress to prevent livelock */
1061 1062 1063 1064 1065 1066
			mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
			status = nfs_wait_on_request(req);
			nfs_release_request(req);
			mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
			if (status < 0)
				break;
1067
			goto restart;
1068
		}
1069
		nfs_request_remove_commit_list(req, cinfo);
1070
		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1071 1072
		nfs_list_add_request(req, dst);
		ret++;
1073
		if ((ret == max) && !cinfo->dreq)
1074
			break;
1075
		cond_resched();
1076 1077
	}
	return ret;
1078
}
1079
EXPORT_SYMBOL_GPL(nfs_scan_commit_list);
1080

L
Linus Torvalds 已提交
1081 1082 1083
/*
 * nfs_scan_commit - Scan an inode for commit requests
 * @inode: NFS inode to scan
1084 1085
 * @dst: mds destination list
 * @cinfo: mds and ds lists of reqs ready to commit
L
Linus Torvalds 已提交
1086 1087 1088 1089
 *
 * Moves requests from the inode's 'commit' request list.
 * The requests are *not* checked to ensure that they form a contiguous set.
 */
1090
int
1091 1092
nfs_scan_commit(struct inode *inode, struct list_head *dst,
		struct nfs_commit_info *cinfo)
L
Linus Torvalds 已提交
1093
{
1094
	int ret = 0;
1095

1096 1097
	if (!atomic_long_read(&cinfo->mds->ncommit))
		return 0;
1098
	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1099
	if (atomic_long_read(&cinfo->mds->ncommit) > 0) {
1100
		const int max = INT_MAX;
1101

1102 1103 1104
		ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
					   cinfo, max);
		ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
1105
	}
1106
	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1107
	return ret;
L
Linus Torvalds 已提交
1108
}
1109

L
Linus Torvalds 已提交
1110
/*
1111 1112
 * Search for an existing write request, and attempt to update
 * it to reflect a new dirty region on a given page.
L
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1113
 *
1114 1115
 * If the attempt fails, then the existing request is flushed out
 * to disk.
L
Linus Torvalds 已提交
1116
 */
1117 1118 1119 1120
static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
		struct page *page,
		unsigned int offset,
		unsigned int bytes)
L
Linus Torvalds 已提交
1121
{
1122 1123 1124 1125 1126
	struct nfs_page *req;
	unsigned int rqend;
	unsigned int end;
	int error;

L
Linus Torvalds 已提交
1127 1128
	end = offset + bytes;

1129 1130 1131
	req = nfs_lock_and_join_requests(page);
	if (IS_ERR_OR_NULL(req))
		return req;
L
Linus Torvalds 已提交
1132

1133 1134 1135 1136 1137 1138 1139 1140 1141
	rqend = req->wb_offset + req->wb_bytes;
	/*
	 * Tell the caller to flush out the request if
	 * the offsets are non-contiguous.
	 * Note: nfs_flush_incompatible() will already
	 * have flushed out requests having wrong owners.
	 */
	if (offset > rqend || end < req->wb_offset)
		goto out_flushme;
L
Linus Torvalds 已提交
1142 1143 1144 1145 1146 1147 1148 1149

	/* Okay, the request matches. Update the region */
	if (offset < req->wb_offset) {
		req->wb_offset = offset;
		req->wb_pgbase = offset;
	}
	if (end > rqend)
		req->wb_bytes = end - req->wb_offset;
1150 1151
	else
		req->wb_bytes = rqend - req->wb_offset;
1152
	req->wb_nio = 0;
1153 1154
	return req;
out_flushme:
1155 1156 1157 1158 1159 1160 1161
	/*
	 * Note: we mark the request dirty here because
	 * nfs_lock_and_join_requests() cannot preserve
	 * commit flags, so we have to replay the write.
	 */
	nfs_mark_request_dirty(req);
	nfs_unlock_and_release_request(req);
1162
	error = nfs_wb_page(inode, page);
1163
	return (error < 0) ? ERR_PTR(error) : NULL;
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175
}

/*
 * Try to update an existing write request, or create one if there is none.
 *
 * Note: Should always be called with the Page Lock held to prevent races
 * if we have to add a new request. Also assumes that the caller has
 * already called nfs_flush_incompatible() if necessary.
 */
static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
		struct page *page, unsigned int offset, unsigned int bytes)
{
1176
	struct inode *inode = page_file_mapping(page)->host;
1177
	struct nfs_page	*req;
L
Linus Torvalds 已提交
1178

1179 1180 1181
	req = nfs_try_to_update_request(inode, page, offset, bytes);
	if (req != NULL)
		goto out;
1182
	req = nfs_create_request(ctx, page, offset, bytes);
1183 1184
	if (IS_ERR(req))
		goto out;
1185
	nfs_inode_add_request(inode, req);
1186
out:
1187
	return req;
L
Linus Torvalds 已提交
1188 1189
}

1190 1191 1192 1193 1194 1195 1196 1197 1198 1199
static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
		unsigned int offset, unsigned int count)
{
	struct nfs_page	*req;

	req = nfs_setup_write_request(ctx, page, offset, count);
	if (IS_ERR(req))
		return PTR_ERR(req);
	/* Update file length */
	nfs_grow_file(page, offset, count);
1200
	nfs_mark_uptodate(req);
1201
	nfs_mark_request_dirty(req);
1202
	nfs_unlock_and_release_request(req);
1203 1204 1205
	return 0;
}

L
Linus Torvalds 已提交
1206 1207
int nfs_flush_incompatible(struct file *file, struct page *page)
{
1208
	struct nfs_open_context *ctx = nfs_file_open_context(file);
1209
	struct nfs_lock_context *l_ctx;
1210
	struct file_lock_context *flctx = file_inode(file)->i_flctx;
L
Linus Torvalds 已提交
1211
	struct nfs_page	*req;
1212
	int do_flush, status;
L
Linus Torvalds 已提交
1213 1214 1215 1216 1217 1218 1219 1220
	/*
	 * Look for a request corresponding to this page. If there
	 * is one, and it belongs to another file, we flush it out
	 * before we try to copy anything into the page. Do this
	 * due to the lack of an ACCESS-type call in NFSv2.
	 * Also do the same if we find a request from an existing
	 * dropped page.
	 */
1221
	do {
1222
		req = nfs_page_find_head_request(page);
1223 1224
		if (req == NULL)
			return 0;
1225
		l_ctx = req->wb_lock_context;
1226
		do_flush = req->wb_page != page ||
1227
			!nfs_match_open_context(nfs_req_openctx(req), ctx);
1228 1229 1230
		if (l_ctx && flctx &&
		    !(list_empty_careful(&flctx->flc_posix) &&
		      list_empty_careful(&flctx->flc_flock))) {
1231
			do_flush |= l_ctx->lockowner != current->files;
1232
		}
L
Linus Torvalds 已提交
1233
		nfs_release_request(req);
1234 1235
		if (!do_flush)
			return 0;
1236
		status = nfs_wb_page(page_file_mapping(page)->host, page);
1237 1238
	} while (status == 0);
	return status;
L
Linus Torvalds 已提交
1239 1240
}

1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
/*
 * Avoid buffered writes when a open context credential's key would
 * expire soon.
 *
 * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
 *
 * Return 0 and set a credential flag which triggers the inode to flush
 * and performs  NFS_FILE_SYNC writes if the key will expired within
 * RPC_KEY_EXPIRE_TIMEO.
 */
int
nfs_key_timeout_notify(struct file *filp, struct inode *inode)
{
	struct nfs_open_context *ctx = nfs_file_open_context(filp);

1256 1257 1258 1259 1260
	if (nfs_ctx_key_to_expire(ctx, inode) &&
	    !ctx->ll_cred)
		/* Already expired! */
		return -EACCES;
	return 0;
1261 1262 1263 1264 1265
}

/*
 * Test if the open context credential key is marked to expire soon.
 */
1266
bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
1267
{
1268
	struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
1269 1270
	struct rpc_cred *cred = ctx->ll_cred;
	struct auth_cred acred = {
1271
		.cred = ctx->cred,
1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
	};

	if (cred && !cred->cr_ops->crmatch(&acred, cred, 0)) {
		put_rpccred(cred);
		ctx->ll_cred = NULL;
		cred = NULL;
	}
	if (!cred)
		cred = auth->au_ops->lookup_cred(auth, &acred, 0);
	if (!cred || IS_ERR(cred))
		return true;
	ctx->ll_cred = cred;
	return !!(cred->cr_ops->crkey_timeout &&
		  cred->cr_ops->crkey_timeout(cred));
1286 1287
}

1288 1289 1290 1291 1292
/*
 * If the page cache is marked as unsafe or invalid, then we can't rely on
 * the PageUptodate() flag. In this case, we will need to turn off
 * write optimisations that depend on the page contents being correct.
 */
1293
static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
1294
{
1295 1296
	struct nfs_inode *nfsi = NFS_I(inode);

1297 1298
	if (nfs_have_delegated_attributes(inode))
		goto out;
1299
	if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
1300
		return false;
1301
	smp_rmb();
1302
	if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
1303 1304
		return false;
out:
1305 1306
	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
		return false;
1307
	return PageUptodate(page) != 0;
1308 1309
}

1310 1311 1312 1313 1314 1315 1316
static bool
is_whole_file_wrlock(struct file_lock *fl)
{
	return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX &&
			fl->fl_type == F_WRLCK;
}

1317 1318 1319 1320 1321
/* If we know the page is up to date, and we're not using byte range locks (or
 * if we have the whole file locked for writing), it may be more efficient to
 * extend the write to cover the entire page in order to avoid fragmentation
 * inefficiencies.
 *
1322 1323
 * If the file is opened for synchronous writes then we can just skip the rest
 * of the checks.
1324 1325 1326
 */
static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode)
{
1327 1328 1329 1330
	int ret;
	struct file_lock_context *flctx = inode->i_flctx;
	struct file_lock *fl;

1331 1332
	if (file->f_flags & O_DSYNC)
		return 0;
1333 1334
	if (!nfs_write_pageuptodate(page, inode))
		return 0;
1335 1336
	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
		return 1;
1337 1338
	if (!flctx || (list_empty_careful(&flctx->flc_flock) &&
		       list_empty_careful(&flctx->flc_posix)))
1339
		return 1;
1340 1341 1342

	/* Check to see if there are whole file write locks */
	ret = 0;
1343
	spin_lock(&flctx->flc_lock);
1344 1345 1346 1347 1348 1349
	if (!list_empty(&flctx->flc_posix)) {
		fl = list_first_entry(&flctx->flc_posix, struct file_lock,
					fl_list);
		if (is_whole_file_wrlock(fl))
			ret = 1;
	} else if (!list_empty(&flctx->flc_flock)) {
1350 1351 1352 1353 1354
		fl = list_first_entry(&flctx->flc_flock, struct file_lock,
					fl_list);
		if (fl->fl_type == F_WRLCK)
			ret = 1;
	}
1355
	spin_unlock(&flctx->flc_lock);
1356
	return ret;
1357 1358
}

L
Linus Torvalds 已提交
1359 1360 1361 1362 1363 1364 1365 1366 1367
/*
 * Update and possibly write a cached page of an NFS file.
 *
 * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
 * things with a page scheduled for an RPC call (e.g. invalidate it).
 */
int nfs_updatepage(struct file *file, struct page *page,
		unsigned int offset, unsigned int count)
{
1368
	struct nfs_open_context *ctx = nfs_file_open_context(file);
1369 1370
	struct address_space *mapping = page_file_mapping(page);
	struct inode	*inode = mapping->host;
L
Linus Torvalds 已提交
1371 1372
	int		status = 0;

1373 1374
	nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);

1375 1376
	dprintk("NFS:       nfs_updatepage(%pD2 %d@%lld)\n",
		file, count, (long long)(page_file_offset(page) + offset));
L
Linus Torvalds 已提交
1377

1378 1379 1380
	if (!count)
		goto out;

1381
	if (nfs_can_extend_write(file, page, inode)) {
1382
		count = max(count + offset, nfs_page_length(page));
L
Linus Torvalds 已提交
1383 1384 1385
		offset = 0;
	}

1386
	status = nfs_writepage_setup(ctx, page, offset, count);
1387
	if (status < 0)
1388
		nfs_set_pageerror(mapping);
1389 1390
	else
		__set_page_dirty_nobuffers(page);
1391
out:
1392
	dprintk("NFS:       nfs_updatepage returns %d (isize %lld)\n",
L
Linus Torvalds 已提交
1393 1394 1395 1396
			status, (long long)i_size_read(inode));
	return status;
}

1397
static int flush_task_priority(int how)
L
Linus Torvalds 已提交
1398 1399 1400 1401 1402 1403 1404 1405 1406 1407
{
	switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
		case FLUSH_HIGHPRI:
			return RPC_PRIORITY_HIGH;
		case FLUSH_LOWPRI:
			return RPC_PRIORITY_LOW;
	}
	return RPC_PRIORITY_NORMAL;
}

1408 1409
static void nfs_initiate_write(struct nfs_pgio_header *hdr,
			       struct rpc_message *msg,
1410
			       const struct nfs_rpc_ops *rpc_ops,
1411
			       struct rpc_task_setup *task_setup_data, int how)
L
Linus Torvalds 已提交
1412
{
1413
	int priority = flush_task_priority(how);
1414

1415
	task_setup_data->priority = priority;
1416
	rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client);
1417 1418
	trace_nfs_initiate_write(hdr->inode, hdr->io_start, hdr->good_bytes,
				 hdr->args.stable);
1419 1420
}

F
Fred 已提交
1421 1422 1423 1424 1425 1426
/* If a nfs_flush_* function fails, it should remove reqs from @head and
 * call this on each, which will prepare them to be retried on next
 * writeback using standard nfs.
 */
static void nfs_redirty_request(struct nfs_page *req)
{
1427 1428
	/* Bump the transmission count */
	req->wb_nio++;
F
Fred 已提交
1429
	nfs_mark_request_dirty(req);
1430
	set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags);
1431
	nfs_end_page_writeback(req);
1432
	nfs_release_request(req);
F
Fred 已提交
1433 1434
}

1435
static void nfs_async_write_error(struct list_head *head, int error)
1436 1437 1438 1439 1440 1441
{
	struct nfs_page	*req;

	while (!list_empty(head)) {
		req = nfs_list_entry(head->next);
		nfs_list_remove_request(req);
1442 1443 1444 1445
		if (nfs_error_is_fatal(error))
			nfs_write_error(req, error);
		else
			nfs_redirty_request(req);
1446 1447 1448
	}
}

1449 1450
static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
{
1451
	nfs_async_write_error(&hdr->pages, 0);
1452 1453
	filemap_fdatawrite_range(hdr->inode->i_mapping, hdr->args.offset,
			hdr->args.offset + hdr->args.count - 1);
1454 1455
}

1456
static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
1457
	.init_hdr = nfs_async_write_init,
1458 1459
	.error_cleanup = nfs_async_write_error,
	.completion = nfs_write_completion,
1460
	.reschedule_io = nfs_async_write_reschedule_io,
1461 1462
};

1463
void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
1464
			       struct inode *inode, int ioflags, bool force_mds,
1465
			       const struct nfs_pgio_completion_ops *compl_ops)
L
Linus Torvalds 已提交
1466
{
1467
	struct nfs_server *server = NFS_SERVER(inode);
1468
	const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
1469 1470 1471 1472 1473

#ifdef CONFIG_NFS_V4_1
	if (server->pnfs_curr_ld && !force_mds)
		pg_ops = server->pnfs_curr_ld->pg_write_ops;
#endif
1474
	nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops,
1475
			server->wsize, ioflags);
1476
}
1477
EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
L
Linus Torvalds 已提交
1478

1479 1480
void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
{
1481 1482
	struct nfs_pgio_mirror *mirror;

1483 1484 1485
	if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
		pgio->pg_ops->pg_cleanup(pgio);

1486
	pgio->pg_ops = &nfs_pgio_rw_ops;
1487 1488 1489 1490 1491

	nfs_pageio_stop_mirroring(pgio);

	mirror = &pgio->pg_mirrors[0];
	mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
1492
}
1493
EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
1494

L
Linus Torvalds 已提交
1495

1496 1497 1498 1499 1500 1501 1502
void nfs_commit_prepare(struct rpc_task *task, void *calldata)
{
	struct nfs_commit_data *data = calldata;

	NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
}

1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513
/*
 * Special version of should_remove_suid() that ignores capabilities.
 */
static int nfs_should_remove_suid(const struct inode *inode)
{
	umode_t mode = inode->i_mode;
	int kill = 0;

	/* suid always must be killed */
	if (unlikely(mode & S_ISUID))
		kill = ATTR_KILL_SUID;
1514

1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526
	/*
	 * sgid without any exec bits is just a mandatory locking mark; leave
	 * it alone.  If some exec bits are set, it's a real sgid; kill it.
	 */
	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
		kill |= ATTR_KILL_SGID;

	if (unlikely(kill && S_ISREG(mode)))
		return kill;

	return 0;
}
1527

1528 1529 1530 1531 1532
static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr,
		struct nfs_fattr *fattr)
{
	struct nfs_pgio_args *argp = &hdr->args;
	struct nfs_pgio_res *resp = &hdr->res;
1533
	u64 size = argp->offset + resp->count;
1534 1535

	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
1536 1537 1538
		fattr->size = size;
	if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) {
		fattr->valid &= ~NFS_ATTR_FATTR_SIZE;
1539
		return;
1540 1541
	}
	if (size != fattr->size)
1542 1543 1544
		return;
	/* Set attribute barrier */
	nfs_fattr_set_barrier(fattr);
1545 1546
	/* ...and update size */
	fattr->valid |= NFS_ATTR_FATTR_SIZE;
1547 1548 1549 1550
}

void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
{
1551
	struct nfs_fattr *fattr = &hdr->fattr;
1552 1553 1554 1555 1556 1557 1558 1559 1560
	struct inode *inode = hdr->inode;

	spin_lock(&inode->i_lock);
	nfs_writeback_check_extend(hdr, fattr);
	nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
	spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL_GPL(nfs_writeback_update_inode);

L
Linus Torvalds 已提交
1561 1562 1563
/*
 * This function is called when the WRITE call is complete.
 */
1564 1565
static int nfs_writeback_done(struct rpc_task *task,
			      struct nfs_pgio_header *hdr,
1566
			      struct inode *inode)
L
Linus Torvalds 已提交
1567
{
1568
	int status;
L
Linus Torvalds 已提交
1569

1570 1571 1572 1573 1574 1575 1576
	/*
	 * ->write_done will attempt to use post-op attributes to detect
	 * conflicting writes by other clients.  A strict interpretation
	 * of close-to-open would allow us to continue caching even if
	 * another writer had changed the file, but some applications
	 * depend on tighter cache coherency when writing.
	 */
1577
	status = NFS_PROTO(inode)->write_done(task, hdr);
1578
	if (status != 0)
1579
		return status;
1580

1581
	nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count);
1582 1583
	trace_nfs_writeback_done(inode, task->tk_status,
				 hdr->args.offset, hdr->res.verf);
1584

1585 1586
	if (hdr->res.verf->committed < hdr->args.stable &&
	    task->tk_status >= 0) {
L
Linus Torvalds 已提交
1587 1588 1589 1590 1591 1592 1593 1594 1595 1596
		/* We tried a write call, but the server did not
		 * commit data to stable storage even though we
		 * requested it.
		 * Note: There is a known bug in Tru64 < 5.0 in which
		 *	 the server reports NFS_DATA_SYNC, but performs
		 *	 NFS_FILE_SYNC. We therefore implement this checking
		 *	 as a dprintk() in order to avoid filling syslog.
		 */
		static unsigned long    complain;

1597
		/* Note this will print the MDS for a DS write */
L
Linus Torvalds 已提交
1598
		if (time_before(complain, jiffies)) {
1599
			dprintk("NFS:       faulty NFS server %s:"
L
Linus Torvalds 已提交
1600
				" (committed = %d) != (stable = %d)\n",
1601
				NFS_SERVER(inode)->nfs_client->cl_hostname,
1602
				hdr->res.verf->committed, hdr->args.stable);
L
Linus Torvalds 已提交
1603 1604 1605
			complain = jiffies + 300 * HZ;
		}
	}
1606 1607

	/* Deal with the suid/sgid bit corner case */
1608 1609 1610 1611 1612
	if (nfs_should_remove_suid(inode)) {
		spin_lock(&inode->i_lock);
		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_OTHER;
		spin_unlock(&inode->i_lock);
	}
1613 1614 1615 1616 1617 1618
	return 0;
}

/*
 * This function is called when the WRITE call is complete.
 */
1619 1620
static void nfs_writeback_result(struct rpc_task *task,
				 struct nfs_pgio_header *hdr)
1621
{
1622 1623
	struct nfs_pgio_args	*argp = &hdr->args;
	struct nfs_pgio_res	*resp = &hdr->res;
1624 1625

	if (resp->count < argp->count) {
L
Linus Torvalds 已提交
1626 1627
		static unsigned long    complain;

1628
		/* This a short write! */
1629
		nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE);
1630

L
Linus Torvalds 已提交
1631
		/* Has the server at least made some progress? */
1632 1633 1634 1635 1636 1637
		if (resp->count == 0) {
			if (time_before(complain, jiffies)) {
				printk(KERN_WARNING
				       "NFS: Server wrote zero bytes, expected %u.\n",
				       argp->count);
				complain = jiffies + 300 * HZ;
L
Linus Torvalds 已提交
1638
			}
1639
			nfs_set_pgio_error(hdr, -EIO, argp->offset);
1640
			task->tk_status = -EIO;
1641
			return;
L
Linus Torvalds 已提交
1642
		}
1643 1644 1645 1646 1647 1648 1649

		/* For non rpc-based layout drivers, retry-through-MDS */
		if (!task->tk_ops) {
			hdr->pnfs_error = -EAGAIN;
			return;
		}

1650 1651 1652
		/* Was this an NFSv2 write or an NFSv3 stable write? */
		if (resp->verf->committed != NFS_UNSTABLE) {
			/* Resend from where the server left off */
1653
			hdr->mds_offset += resp->count;
1654 1655 1656 1657 1658 1659 1660 1661
			argp->offset += resp->count;
			argp->pgbase += resp->count;
			argp->count -= resp->count;
		} else {
			/* Resend as a stable write in order to avoid
			 * headaches in the case of a server crash.
			 */
			argp->stable = NFS_FILE_SYNC;
L
Linus Torvalds 已提交
1662
		}
1663
		rpc_restart_call_prepare(task);
L
Linus Torvalds 已提交
1664 1665 1666
	}
}

1667
static int wait_on_commit(struct nfs_mds_commit_info *cinfo)
1668
{
1669 1670
	return wait_var_event_killable(&cinfo->rpcs_out,
				       !atomic_read(&cinfo->rpcs_out));
1671
}
1672

1673 1674 1675
static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
{
	atomic_inc(&cinfo->rpcs_out);
1676 1677
}

1678
static void nfs_commit_end(struct nfs_mds_commit_info *cinfo)
1679
{
1680
	if (atomic_dec_and_test(&cinfo->rpcs_out))
1681
		wake_up_var(&cinfo->rpcs_out);
1682 1683
}

1684
void nfs_commitdata_release(struct nfs_commit_data *data)
L
Linus Torvalds 已提交
1685
{
1686 1687
	put_nfs_open_context(data->context);
	nfs_commit_free(data);
L
Linus Torvalds 已提交
1688
}
1689
EXPORT_SYMBOL_GPL(nfs_commitdata_release);
L
Linus Torvalds 已提交
1690

1691
int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
1692
			const struct nfs_rpc_ops *nfs_ops,
1693
			const struct rpc_call_ops *call_ops,
1694
			int how, int flags)
L
Linus Torvalds 已提交
1695
{
1696
	struct rpc_task *task;
1697
	int priority = flush_task_priority(how);
1698 1699 1700
	struct rpc_message msg = {
		.rpc_argp = &data->args,
		.rpc_resp = &data->res,
1701
		.rpc_cred = data->cred,
1702
	};
1703
	struct rpc_task_setup task_setup_data = {
1704
		.task = &data->task,
1705
		.rpc_client = clnt,
1706
		.rpc_message = &msg,
1707
		.callback_ops = call_ops,
1708
		.callback_data = data,
1709
		.workqueue = nfsiod_workqueue,
1710
		.flags = RPC_TASK_ASYNC | flags,
1711
		.priority = priority,
1712
	};
1713
	/* Set up the initial task struct.  */
1714
	nfs_ops->commit_setup(data, &msg, &task_setup_data.rpc_client);
1715
	trace_nfs_initiate_commit(data);
1716

1717
	dprintk("NFS: initiated commit call\n");
1718 1719 1720 1721 1722 1723 1724 1725 1726

	task = rpc_run_task(&task_setup_data);
	if (IS_ERR(task))
		return PTR_ERR(task);
	if (how & FLUSH_SYNC)
		rpc_wait_for_completion_task(task);
	rpc_put_task(task);
	return 0;
}
1727
EXPORT_SYMBOL_GPL(nfs_initiate_commit);
1728

1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740
static loff_t nfs_get_lwb(struct list_head *head)
{
	loff_t lwb = 0;
	struct nfs_page *req;

	list_for_each_entry(req, head, wb_list)
		if (lwb < (req_offset(req) + req->wb_bytes))
			lwb = req_offset(req) + req->wb_bytes;

	return lwb;
}

1741 1742 1743
/*
 * Set up the argument/result storage required for the RPC call.
 */
1744
void nfs_init_commit(struct nfs_commit_data *data,
1745 1746 1747
		     struct list_head *head,
		     struct pnfs_layout_segment *lseg,
		     struct nfs_commit_info *cinfo)
1748 1749
{
	struct nfs_page *first = nfs_list_entry(head->next);
1750 1751
	struct nfs_open_context *ctx = nfs_req_openctx(first);
	struct inode *inode = d_inode(ctx->dentry);
L
Linus Torvalds 已提交
1752 1753 1754 1755 1756 1757 1758

	/* Set up the RPC argument and reply structs
	 * NB: take care not to mess about with data->commit et al. */

	list_splice_init(head, &data->pages);

	data->inode	  = inode;
1759
	data->cred	  = ctx->cred;
1760
	data->lseg	  = lseg; /* reference transferred */
1761 1762 1763
	/* only set lwb for pnfs commit */
	if (lseg)
		data->lwb = nfs_get_lwb(&data->pages);
1764
	data->mds_ops     = &nfs_commit_ops;
1765
	data->completion_ops = cinfo->completion_ops;
1766
	data->dreq	  = cinfo->dreq;
L
Linus Torvalds 已提交
1767 1768

	data->args.fh     = NFS_FH(data->inode);
1769 1770 1771
	/* Note: we always request a commit of the entire inode */
	data->args.offset = 0;
	data->args.count  = 0;
1772
	data->context     = get_nfs_open_context(ctx);
L
Linus Torvalds 已提交
1773 1774
	data->res.fattr   = &data->fattr;
	data->res.verf    = &data->verf;
1775
	nfs_fattr_init(&data->fattr);
L
Linus Torvalds 已提交
1776
}
1777
EXPORT_SYMBOL_GPL(nfs_init_commit);
L
Linus Torvalds 已提交
1778

1779
void nfs_retry_commit(struct list_head *page_list,
1780
		      struct pnfs_layout_segment *lseg,
1781 1782
		      struct nfs_commit_info *cinfo,
		      u32 ds_commit_idx)
1783 1784 1785 1786 1787 1788
{
	struct nfs_page *req;

	while (!list_empty(page_list)) {
		req = nfs_list_entry(page_list->next);
		nfs_list_remove_request(req);
1789
		nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx);
1790 1791
		if (!cinfo->dreq)
			nfs_clear_page_commit(req->wb_page);
1792
		nfs_unlock_and_release_request(req);
1793 1794
	}
}
1795
EXPORT_SYMBOL_GPL(nfs_retry_commit);
1796

1797 1798 1799 1800 1801 1802 1803
static void
nfs_commit_resched_write(struct nfs_commit_info *cinfo,
		struct nfs_page *req)
{
	__set_page_dirty_nobuffers(req->wb_page);
}

L
Linus Torvalds 已提交
1804 1805 1806 1807
/*
 * Commit dirty pages
 */
static int
1808 1809
nfs_commit_list(struct inode *inode, struct list_head *head, int how,
		struct nfs_commit_info *cinfo)
L
Linus Torvalds 已提交
1810
{
1811
	struct nfs_commit_data	*data;
L
Linus Torvalds 已提交
1812

1813 1814 1815 1816
	/* another commit raced with us */
	if (list_empty(head))
		return 0;

N
NeilBrown 已提交
1817
	data = nfs_commitdata_alloc(true);
L
Linus Torvalds 已提交
1818 1819

	/* Set up the argument struct */
1820 1821
	nfs_init_commit(data, head, NULL, cinfo);
	atomic_inc(&cinfo->mds->rpcs_out);
1822 1823
	return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
				   data->mds_ops, how, 0);
1824 1825
}

L
Linus Torvalds 已提交
1826 1827 1828
/*
 * COMMIT call returned
 */
1829
static void nfs_commit_done(struct rpc_task *task, void *calldata)
L
Linus Torvalds 已提交
1830
{
1831
	struct nfs_commit_data	*data = calldata;
L
Linus Torvalds 已提交
1832

1833
        dprintk("NFS: %5u nfs_commit_done (status %d)\n",
L
Linus Torvalds 已提交
1834 1835
                                task->tk_pid, task->tk_status);

1836
	/* Call the NFS version-specific code */
1837
	NFS_PROTO(data->inode)->commit_done(task, data);
1838
	trace_nfs_commit_done(data);
1839 1840
}

1841
static void nfs_commit_release_pages(struct nfs_commit_data *data)
1842
{
1843
	const struct nfs_writeverf *verf = data->res.verf;
1844
	struct nfs_page	*req;
1845
	int status = data->task.tk_status;
1846
	struct nfs_commit_info cinfo;
1847
	struct nfs_server *nfss;
1848

L
Linus Torvalds 已提交
1849 1850 1851
	while (!list_empty(&data->pages)) {
		req = nfs_list_entry(data->pages.next);
		nfs_list_remove_request(req);
1852 1853
		if (req->wb_page)
			nfs_clear_page_commit(req->wb_page);
L
Linus Torvalds 已提交
1854

1855
		dprintk("NFS:       commit (%s/%llu %d@%lld)",
1856 1857
			nfs_req_openctx(req)->dentry->d_sb->s_id,
			(unsigned long long)NFS_FILEID(d_inode(nfs_req_openctx(req)->dentry)),
L
Linus Torvalds 已提交
1858 1859
			req->wb_bytes,
			(long long)req_offset(req));
1860
		if (status < 0) {
1861
			if (req->wb_page) {
1862
				trace_nfs_commit_error(req, status);
1863
				nfs_mapping_set_error(req->wb_page, status);
1864
				nfs_inode_remove_request(req);
1865
			}
1866
			dprintk_cont(", error = %d\n", status);
L
Linus Torvalds 已提交
1867 1868 1869 1870 1871
			goto next;
		}

		/* Okay, COMMIT succeeded, apparently. Check the verifier
		 * returned by the server against all stored verfs. */
1872 1873
		if (verf->committed > NFS_UNSTABLE &&
		    !nfs_write_verifier_cmp(&req->wb_verf, &verf->verifier)) {
L
Linus Torvalds 已提交
1874
			/* We have a match */
1875 1876
			if (req->wb_page)
				nfs_inode_remove_request(req);
1877
			dprintk_cont(" OK\n");
L
Linus Torvalds 已提交
1878 1879 1880
			goto next;
		}
		/* We have a mismatch. Write the page again */
1881
		dprintk_cont(" mismatch\n");
F
Fred 已提交
1882
		nfs_mark_request_dirty(req);
1883
		set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags);
L
Linus Torvalds 已提交
1884
	next:
1885
		nfs_unlock_and_release_request(req);
1886 1887
		/* Latency breaker */
		cond_resched();
L
Linus Torvalds 已提交
1888
	}
1889 1890
	nfss = NFS_SERVER(data->inode);
	if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
1891
		clear_bdi_congested(inode_to_bdi(data->inode), BLK_RW_ASYNC);
1892

1893
	nfs_init_cinfo(&cinfo, data->inode, data->dreq);
1894
	nfs_commit_end(cinfo.mds);
1895 1896 1897 1898
}

static void nfs_commit_release(void *calldata)
{
1899
	struct nfs_commit_data *data = calldata;
1900

1901
	data->completion_ops->completion(data);
1902
	nfs_commitdata_release(calldata);
L
Linus Torvalds 已提交
1903
}
1904 1905

static const struct rpc_call_ops nfs_commit_ops = {
1906
	.rpc_call_prepare = nfs_commit_prepare,
1907 1908 1909
	.rpc_call_done = nfs_commit_done,
	.rpc_release = nfs_commit_release,
};
L
Linus Torvalds 已提交
1910

1911 1912
static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
	.completion = nfs_commit_release_pages,
1913
	.resched_write = nfs_commit_resched_write,
1914 1915
};

1916 1917
int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
			    int how, struct nfs_commit_info *cinfo)
1918 1919 1920
{
	int status;

1921
	status = pnfs_commit_list(inode, head, how, cinfo);
1922
	if (status == PNFS_NOT_ATTEMPTED)
1923
		status = nfs_commit_list(inode, head, how, cinfo);
1924 1925 1926
	return status;
}

1927 1928
static int __nfs_commit_inode(struct inode *inode, int how,
		struct writeback_control *wbc)
L
Linus Torvalds 已提交
1929 1930
{
	LIST_HEAD(head);
1931
	struct nfs_commit_info cinfo;
1932
	int may_wait = how & FLUSH_SYNC;
1933
	int ret, nscan;
L
Linus Torvalds 已提交
1934

1935
	nfs_init_cinfo_from_inode(&cinfo, inode);
1936
	nfs_commit_begin(cinfo.mds);
1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954
	for (;;) {
		ret = nscan = nfs_scan_commit(inode, &head, &cinfo);
		if (ret <= 0)
			break;
		ret = nfs_generic_commit_list(inode, &head, how, &cinfo);
		if (ret < 0)
			break;
		ret = 0;
		if (wbc && wbc->sync_mode == WB_SYNC_NONE) {
			if (nscan < wbc->nr_to_write)
				wbc->nr_to_write -= nscan;
			else
				wbc->nr_to_write = 0;
		}
		if (nscan < INT_MAX)
			break;
		cond_resched();
	}
1955
	nfs_commit_end(cinfo.mds);
1956 1957 1958 1959 1960 1961 1962 1963
	if (ret || !may_wait)
		return ret;
	return wait_on_commit(cinfo.mds);
}

int nfs_commit_inode(struct inode *inode, int how)
{
	return __nfs_commit_inode(inode, how, NULL);
L
Linus Torvalds 已提交
1964
}
1965
EXPORT_SYMBOL_GPL(nfs_commit_inode);
1966

1967
int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
1968
{
1969 1970 1971
	struct nfs_inode *nfsi = NFS_I(inode);
	int flags = FLUSH_SYNC;
	int ret = 0;
1972

1973
	if (wbc->sync_mode == WB_SYNC_NONE) {
1974 1975 1976 1977
		/* no commits means nothing needs to be done */
		if (!atomic_long_read(&nfsi->commit_info.ncommit))
			goto check_requests_outstanding;

1978 1979 1980
		/* Don't commit yet if this is a non-blocking flush and there
		 * are a lot of outstanding writes for this mapping.
		 */
1981
		if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
1982
			goto out_mark_dirty;
1983

1984
		/* don't wait for the COMMIT response */
1985
		flags = 0;
1986 1987
	}

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997
	ret = __nfs_commit_inode(inode, flags, wbc);
	if (!ret) {
		if (flags & FLUSH_SYNC)
			return 0;
	} else if (atomic_long_read(&nfsi->commit_info.ncommit))
		goto out_mark_dirty;

check_requests_outstanding:
	if (!atomic_read(&nfsi->commit_info.rpcs_out))
		return ret;
1998
out_mark_dirty:
1999 2000 2001
	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
	return ret;
}
2002
EXPORT_SYMBOL_GPL(nfs_write_inode);
2003

2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
/*
 * Wrapper for filemap_write_and_wait_range()
 *
 * Needed for pNFS in order to ensure data becomes visible to the
 * client.
 */
int nfs_filemap_write_and_wait_range(struct address_space *mapping,
		loff_t lstart, loff_t lend)
{
	int ret;

	ret = filemap_write_and_wait_range(mapping, lstart, lend);
	if (ret == 0)
		ret = pnfs_sync_inode(mapping->host, true);
	return ret;
}
EXPORT_SYMBOL_GPL(nfs_filemap_write_and_wait_range);

2022 2023 2024 2025
/*
 * flush the inode to disk.
 */
int nfs_wb_all(struct inode *inode)
2026
{
2027 2028 2029 2030
	int ret;

	trace_nfs_writeback_inode_enter(inode);

2031
	ret = filemap_write_and_wait(inode->i_mapping);
2032 2033 2034 2035 2036 2037 2038
	if (ret)
		goto out;
	ret = nfs_commit_inode(inode, FLUSH_SYNC);
	if (ret < 0)
		goto out;
	pnfs_sync_inode(inode, true);
	ret = 0;
2039

2040
out:
2041 2042
	trace_nfs_writeback_inode_exit(inode, ret);
	return ret;
2043
}
2044
EXPORT_SYMBOL_GPL(nfs_wb_all);
2045

2046 2047 2048 2049 2050
int nfs_wb_page_cancel(struct inode *inode, struct page *page)
{
	struct nfs_page *req;
	int ret = 0;

2051 2052 2053 2054
	wait_on_page_writeback(page);

	/* blocking call to cancel all requests and join to a single (head)
	 * request */
2055
	req = nfs_lock_and_join_requests(page);
2056 2057 2058 2059 2060 2061 2062 2063 2064 2065

	if (IS_ERR(req)) {
		ret = PTR_ERR(req);
	} else if (req) {
		/* all requests from this page have been cancelled by
		 * nfs_lock_and_join_requests, so just remove the head
		 * request from the inode / page_private pointer and
		 * release it */
		nfs_inode_remove_request(req);
		nfs_unlock_and_release_request(req);
2066
	}
2067

2068 2069 2070
	return ret;
}

2071 2072 2073
/*
 * Write back all requests on one page - we do this before reading it.
 */
2074
int nfs_wb_page(struct inode *inode, struct page *page)
2075
{
2076
	loff_t range_start = page_file_offset(page);
2077
	loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
2078 2079
	struct writeback_control wbc = {
		.sync_mode = WB_SYNC_ALL,
2080
		.nr_to_write = 0,
2081 2082 2083 2084
		.range_start = range_start,
		.range_end = range_end,
	};
	int ret;
2085

2086 2087
	trace_nfs_writeback_page_enter(inode);

2088
	for (;;) {
2089
		wait_on_page_writeback(page);
2090
		if (clear_page_dirty_for_io(page)) {
2091
			ret = nfs_writepage_locked(page, &wbc);
2092 2093
			if (ret < 0)
				goto out_error;
2094
			continue;
2095
		}
2096
		ret = 0;
2097 2098 2099
		if (!PagePrivate(page))
			break;
		ret = nfs_commit_inode(inode, FLUSH_SYNC);
2100
		if (ret < 0)
2101
			goto out_error;
2102
	}
2103
out_error:
2104
	trace_nfs_writeback_page_exit(inode, ret);
2105
	return ret;
2106 2107
}

2108 2109
#ifdef CONFIG_MIGRATION
int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
2110
		struct page *page, enum migrate_mode mode)
2111
{
2112 2113 2114 2115 2116 2117 2118 2119 2120 2121
	/*
	 * If PagePrivate is set, then the page is currently associated with
	 * an in-progress read or write request. Don't try to migrate it.
	 *
	 * FIXME: we could do this in principle, but we'll need a way to ensure
	 *        that we can safely release the inode reference while holding
	 *        the page lock.
	 */
	if (PagePrivate(page))
		return -EBUSY;
2122

2123 2124
	if (!nfs_fscache_release_page(page, GFP_KERNEL))
		return -EBUSY;
2125

2126
	return migrate_page(mapping, newpage, page, mode);
2127 2128 2129
}
#endif

D
David Howells 已提交
2130
int __init nfs_init_writepagecache(void)
L
Linus Torvalds 已提交
2131 2132
{
	nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
2133
					     sizeof(struct nfs_pgio_header),
L
Linus Torvalds 已提交
2134
					     0, SLAB_HWCACHE_ALIGN,
2135
					     NULL);
L
Linus Torvalds 已提交
2136 2137 2138
	if (nfs_wdata_cachep == NULL)
		return -ENOMEM;

2139 2140
	nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
						     nfs_wdata_cachep);
L
Linus Torvalds 已提交
2141
	if (nfs_wdata_mempool == NULL)
2142
		goto out_destroy_write_cache;
L
Linus Torvalds 已提交
2143

2144 2145 2146 2147 2148
	nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
					     sizeof(struct nfs_commit_data),
					     0, SLAB_HWCACHE_ALIGN,
					     NULL);
	if (nfs_cdata_cachep == NULL)
2149
		goto out_destroy_write_mempool;
2150

2151
	nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
2152
						      nfs_cdata_cachep);
L
Linus Torvalds 已提交
2153
	if (nfs_commit_mempool == NULL)
2154
		goto out_destroy_commit_cache;
L
Linus Torvalds 已提交
2155

2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171
	/*
	 * NFS congestion size, scale with available memory.
	 *
	 *  64MB:    8192k
	 * 128MB:   11585k
	 * 256MB:   16384k
	 * 512MB:   23170k
	 *   1GB:   32768k
	 *   2GB:   46340k
	 *   4GB:   65536k
	 *   8GB:   92681k
	 *  16GB:  131072k
	 *
	 * This allows larger machines to have larger/more transfers.
	 * Limit the default to 256M
	 */
2172
	nfs_congestion_kb = (16*int_sqrt(totalram_pages())) << (PAGE_SHIFT-10);
2173 2174 2175
	if (nfs_congestion_kb > 256*1024)
		nfs_congestion_kb = 256*1024;

L
Linus Torvalds 已提交
2176
	return 0;
2177 2178 2179 2180 2181 2182 2183 2184

out_destroy_commit_cache:
	kmem_cache_destroy(nfs_cdata_cachep);
out_destroy_write_mempool:
	mempool_destroy(nfs_wdata_mempool);
out_destroy_write_cache:
	kmem_cache_destroy(nfs_wdata_cachep);
	return -ENOMEM;
L
Linus Torvalds 已提交
2185 2186
}

2187
void nfs_destroy_writepagecache(void)
L
Linus Torvalds 已提交
2188 2189
{
	mempool_destroy(nfs_commit_mempool);
2190
	kmem_cache_destroy(nfs_cdata_cachep);
L
Linus Torvalds 已提交
2191
	mempool_destroy(nfs_wdata_mempool);
2192
	kmem_cache_destroy(nfs_wdata_cachep);
L
Linus Torvalds 已提交
2193 2194
}

2195 2196 2197
static const struct nfs_rw_ops nfs_rw_write_ops = {
	.rw_alloc_header	= nfs_writehdr_alloc,
	.rw_free_header		= nfs_writehdr_free,
2198 2199
	.rw_done		= nfs_writeback_done,
	.rw_result		= nfs_writeback_result,
2200
	.rw_initiate		= nfs_initiate_write,
2201
};
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