[linux.git] / fs / 9p / cache.c

/*
 * V9FS cache definitions.
 *
 *  Copyright (C) 2009 by Abhishek Kulkarni <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/jiffies.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <net/9p/9p.h>

#include "v9fs.h"
#include "cache.h"

#define CACHETAG_LEN  11

struct fscache_netfs v9fs_cache_netfs = {
	.name 		= "9p",
	.version 	= 0,
};

/**
 * v9fs_random_cachetag - Generate a random tag to be associated
 *			  with a new cache session.
 *
 * The value of jiffies is used for a fairly randomly cache tag.
 */

static
int v9fs_random_cachetag(struct v9fs_session_info *v9ses)
{
	v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL);
	if (!v9ses->cachetag)
		return -ENOMEM;

	return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies);
}

static uint16_t v9fs_cache_session_get_key(const void *cookie_netfs_data,
					   void *buffer, uint16_t bufmax)
{
	struct v9fs_session_info *v9ses;
	uint16_t klen = 0;

	v9ses = (struct v9fs_session_info *)cookie_netfs_data;
	P9_DPRINTK(P9_DEBUG_FSC, "session %p buf %p size %u", v9ses,
		   buffer, bufmax);

	if (v9ses->cachetag)
		klen = strlen(v9ses->cachetag);

	if (klen > bufmax)
		return 0;

	memcpy(buffer, v9ses->cachetag, klen);
	P9_DPRINTK(P9_DEBUG_FSC, "cache session tag %s", v9ses->cachetag);
	return klen;
}

const struct fscache_cookie_def v9fs_cache_session_index_def = {
	.name		= "9P.session",
	.type		= FSCACHE_COOKIE_TYPE_INDEX,
	.get_key	= v9fs_cache_session_get_key,
};

void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses)
{
	/* If no cache session tag was specified, we generate a random one. */
	if (!v9ses->cachetag)
		v9fs_random_cachetag(v9ses);

	v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index,
						&v9fs_cache_session_index_def,
						v9ses);
	P9_DPRINTK(P9_DEBUG_FSC, "session %p get cookie %p", v9ses,
		   v9ses->fscache);
}

void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses)
{
	P9_DPRINTK(P9_DEBUG_FSC, "session %p put cookie %p", v9ses,
		   v9ses->fscache);
	fscache_relinquish_cookie(v9ses->fscache, 0);
	v9ses->fscache = NULL;
}


static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data,
					 void *buffer, uint16_t bufmax)
{
	const struct v9fs_inode *v9inode = cookie_netfs_data;
	memcpy(buffer, &v9inode->qid.path, sizeof(v9inode->qid.path));
	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get key %llu", &v9inode->vfs_inode,
		   v9inode->qid.path);
	return sizeof(v9inode->qid.path);
}

static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
				      uint64_t *size)
{
	const struct v9fs_inode *v9inode = cookie_netfs_data;
	*size = i_size_read(&v9inode->vfs_inode);

	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get attr %llu", &v9inode->vfs_inode,
		   *size);
}

static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data,
					 void *buffer, uint16_t buflen)
{
	const struct v9fs_inode *v9inode = cookie_netfs_data;
	memcpy(buffer, &v9inode->qid.version, sizeof(v9inode->qid.version));
	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get aux %u", &v9inode->vfs_inode,
		   v9inode->qid.version);
	return sizeof(v9inode->qid.version);
}

static enum
fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
					    const void *buffer,
					    uint16_t buflen)
{
	const struct v9fs_inode *v9inode = cookie_netfs_data;

	if (buflen != sizeof(v9inode->qid.version))
		return FSCACHE_CHECKAUX_OBSOLETE;

	if (memcmp(buffer, &v9inode->qid.version,
		   sizeof(v9inode->qid.version)))
		return FSCACHE_CHECKAUX_OBSOLETE;

	return FSCACHE_CHECKAUX_OKAY;
}

static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data)
{
	struct v9fs_inode *v9inode = cookie_netfs_data;
	struct pagevec pvec;
	pgoff_t first;
	int loop, nr_pages;

	pagevec_init(&pvec, 0);
	first = 0;

	for (;;) {
		nr_pages = pagevec_lookup(&pvec, v9inode->vfs_inode.i_mapping,
					  first,
					  PAGEVEC_SIZE - pagevec_count(&pvec));
		if (!nr_pages)
			break;

		for (loop = 0; loop < nr_pages; loop++)
			ClearPageFsCache(pvec.pages[loop]);

		first = pvec.pages[nr_pages - 1]->index + 1;

		pvec.nr = nr_pages;
		pagevec_release(&pvec);
		cond_resched();
	}
}

const struct fscache_cookie_def v9fs_cache_inode_index_def = {
	.name		= "9p.inode",
	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
	.get_key	= v9fs_cache_inode_get_key,
	.get_attr	= v9fs_cache_inode_get_attr,
	.get_aux	= v9fs_cache_inode_get_aux,
	.check_aux	= v9fs_cache_inode_check_aux,
	.now_uncached	= v9fs_cache_inode_now_uncached,
};

void v9fs_cache_inode_get_cookie(struct inode *inode)
{
	struct v9fs_inode *v9inode;
	struct v9fs_session_info *v9ses;

	if (!S_ISREG(inode->i_mode))
		return;

	v9inode = V9FS_I(inode);
	if (v9inode->fscache)
		return;

	v9ses = v9fs_inode2v9ses(inode);
	v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
						  &v9fs_cache_inode_index_def,
						  v9inode);

	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get cookie %p", inode,
		   v9inode->fscache);
}

void v9fs_cache_inode_put_cookie(struct inode *inode)
{
	struct v9fs_inode *v9inode = V9FS_I(inode);

	if (!v9inode->fscache)
		return;
	P9_DPRINTK(P9_DEBUG_FSC, "inode %p put cookie %p", inode,
		   v9inode->fscache);

	fscache_relinquish_cookie(v9inode->fscache, 0);
	v9inode->fscache = NULL;
}

void v9fs_cache_inode_flush_cookie(struct inode *inode)
{
	struct v9fs_inode *v9inode = V9FS_I(inode);

	if (!v9inode->fscache)
		return;
	P9_DPRINTK(P9_DEBUG_FSC, "inode %p flush cookie %p", inode,
		   v9inode->fscache);

	fscache_relinquish_cookie(v9inode->fscache, 1);
	v9inode->fscache = NULL;
}

void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp)
{
	struct v9fs_inode *v9inode = V9FS_I(inode);
	struct p9_fid *fid;

	if (!v9inode->fscache)
		return;

	spin_lock(&v9inode->fscache_lock);
	fid = filp->private_data;
	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
		v9fs_cache_inode_flush_cookie(inode);
	else
		v9fs_cache_inode_get_cookie(inode);

	spin_unlock(&v9inode->fscache_lock);
}

void v9fs_cache_inode_reset_cookie(struct inode *inode)
{
	struct v9fs_inode *v9inode = V9FS_I(inode);
	struct v9fs_session_info *v9ses;
	struct fscache_cookie *old;

	if (!v9inode->fscache)
		return;

	old = v9inode->fscache;

	spin_lock(&v9inode->fscache_lock);
	fscache_relinquish_cookie(v9inode->fscache, 1);

	v9ses = v9fs_inode2v9ses(inode);
	v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
						  &v9fs_cache_inode_index_def,
						  v9inode);
	P9_DPRINTK(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p",
		   inode, old, v9inode->fscache);

	spin_unlock(&v9inode->fscache_lock);
}

int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
{
	struct inode *inode = page->mapping->host;
	struct v9fs_inode *v9inode = V9FS_I(inode);

	BUG_ON(!v9inode->fscache);

	return fscache_maybe_release_page(v9inode->fscache, page, gfp);
}

void __v9fs_fscache_invalidate_page(struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct v9fs_inode *v9inode = V9FS_I(inode);

	BUG_ON(!v9inode->fscache);

	if (PageFsCache(page)) {
		fscache_wait_on_page_write(v9inode->fscache, page);
		BUG_ON(!PageLocked(page));
		fscache_uncache_page(v9inode->fscache, page);
	}
}

static void v9fs_vfs_readpage_complete(struct page *page, void *data,
				       int error)
{
	if (!error)
		SetPageUptodate(page);

	unlock_page(page);
}

/**
 * __v9fs_readpage_from_fscache - read a page from cache
 *
 * Returns 0 if the pages are in cache and a BIO is submitted,
 * 1 if the pages are not in cache and -error otherwise.
 */

int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page)
{
	int ret;
	const struct v9fs_inode *v9inode = V9FS_I(inode);

	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
	if (!v9inode->fscache)
		return -ENOBUFS;

	ret = fscache_read_or_alloc_page(v9inode->fscache,
					 page,
					 v9fs_vfs_readpage_complete,
					 NULL,
					 GFP_KERNEL);
	switch (ret) {
	case -ENOBUFS:
	case -ENODATA:
		P9_DPRINTK(P9_DEBUG_FSC, "page/inode not in cache %d", ret);
		return 1;
	case 0:
		P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted");
		return ret;
	default:
		P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret);
		return ret;
	}
}

/**
 * __v9fs_readpages_from_fscache - read multiple pages from cache
 *
 * Returns 0 if the pages are in cache and a BIO is submitted,
 * 1 if the pages are not in cache and -error otherwise.
 */

int __v9fs_readpages_from_fscache(struct inode *inode,
				  struct address_space *mapping,
				  struct list_head *pages,
				  unsigned *nr_pages)
{
	int ret;
	const struct v9fs_inode *v9inode = V9FS_I(inode);

	P9_DPRINTK(P9_DEBUG_FSC, "inode %p pages %u", inode, *nr_pages);
	if (!v9inode->fscache)
		return -ENOBUFS;

	ret = fscache_read_or_alloc_pages(v9inode->fscache,
					  mapping, pages, nr_pages,
					  v9fs_vfs_readpage_complete,
					  NULL,
					  mapping_gfp_mask(mapping));
	switch (ret) {
	case -ENOBUFS:
	case -ENODATA:
		P9_DPRINTK(P9_DEBUG_FSC, "pages/inodes not in cache %d", ret);
		return 1;
	case 0:
		BUG_ON(!list_empty(pages));
		BUG_ON(*nr_pages != 0);
		P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted");
		return ret;
	default:
		P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret);
		return ret;
	}
}

/**
 * __v9fs_readpage_to_fscache - write a page to the cache
 *
 */

void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
{
	int ret;
	const struct v9fs_inode *v9inode = V9FS_I(inode);

	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
	ret = fscache_write_page(v9inode->fscache, page, GFP_KERNEL);
	P9_DPRINTK(P9_DEBUG_FSC, "ret =  %d", ret);
	if (ret != 0)
		v9fs_uncache_page(inode, page);
}

/*
 * wait for a page to complete writing to the cache
 */
void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
{
	const struct v9fs_inode *v9inode = V9FS_I(inode);
	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
	if (PageFsCache(page))
		fscache_wait_on_page_write(v9inode->fscache, page);
}
Commit	Line	Data
60e78d2c AK	1	/*
	2	* V9FS cache definitions.
	3	*
	4	* Copyright (C) 2009 by Abhishek Kulkarni <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2
	8	* as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to:
	17	* Free Software Foundation
	18	* 51 Franklin Street, Fifth Floor
	19	* Boston, MA 02111-1301 USA
	20	*
	21	*/
	22
	23	#include <linux/jiffies.h>
	24	#include <linux/file.h>
5a0e3ad6	25	#include <linux/slab.h>
60e78d2c AK	26	#include <linux/stat.h>
	27	#include <linux/sched.h>
	28	#include <linux/fs.h>
	29	#include <net/9p/9p.h>
	30
	31	#include "v9fs.h"
	32	#include "cache.h"
	33
	34	#define CACHETAG_LEN 11
	35
60e78d2c AK	36	struct fscache_netfs v9fs_cache_netfs = {
	37	.name = "9p",
	38	.version = 0,
	39	};
	40
60e78d2c AK	41	/**
	42	* v9fs_random_cachetag - Generate a random tag to be associated
	43	* with a new cache session.
	44	*
	45	* The value of jiffies is used for a fairly randomly cache tag.
	46	*/
	47
	48	static
	49	int v9fs_random_cachetag(struct v9fs_session_info *v9ses)
	50	{
	51	v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL);
	52	if (!v9ses->cachetag)
	53	return -ENOMEM;
	54
	55	return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies);
	56	}
	57
	58	static uint16_t v9fs_cache_session_get_key(const void *cookie_netfs_data,
	59	void *buffer, uint16_t bufmax)
	60	{
	61	struct v9fs_session_info *v9ses;
	62	uint16_t klen = 0;
	63
	64	v9ses = (struct v9fs_session_info *)cookie_netfs_data;
	65	P9_DPRINTK(P9_DEBUG_FSC, "session %p buf %p size %u", v9ses,
	66	buffer, bufmax);
	67
	68	if (v9ses->cachetag)
	69	klen = strlen(v9ses->cachetag);
	70
	71	if (klen > bufmax)
	72	return 0;
	73
	74	memcpy(buffer, v9ses->cachetag, klen);
	75	P9_DPRINTK(P9_DEBUG_FSC, "cache session tag %s", v9ses->cachetag);
	76	return klen;
	77	}
	78
	79	const struct fscache_cookie_def v9fs_cache_session_index_def = {
a78ce05d AK	80	.name = "9P.session",
	81	.type = FSCACHE_COOKIE_TYPE_INDEX,
	82	.get_key = v9fs_cache_session_get_key,
60e78d2c AK	83	};
	84
	85	void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses)
	86	{
	87	/* If no cache session tag was specified, we generate a random one. */
	88	if (!v9ses->cachetag)
	89	v9fs_random_cachetag(v9ses);
	90
	91	v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index,
	92	&v9fs_cache_session_index_def,
	93	v9ses);
	94	P9_DPRINTK(P9_DEBUG_FSC, "session %p get cookie %p", v9ses,
	95	v9ses->fscache);
	96	}
	97
	98	void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses)
	99	{
	100	P9_DPRINTK(P9_DEBUG_FSC, "session %p put cookie %p", v9ses,
	101	v9ses->fscache);
	102	fscache_relinquish_cookie(v9ses->fscache, 0);
	103	v9ses->fscache = NULL;
	104	}
	105
	106
	107	static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data,
	108	void *buffer, uint16_t bufmax)
	109	{
a78ce05d	110	const struct v9fs_inode *v9inode = cookie_netfs_data;
fd2421f5	111	memcpy(buffer, &v9inode->qid.path, sizeof(v9inode->qid.path));
a78ce05d	112	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get key %llu", &v9inode->vfs_inode,
fd2421f5 AK	113	v9inode->qid.path);
fd2421f5 AK	114	return sizeof(v9inode->qid.path);
60e78d2c AK	115	}
	116
	117	static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
	118	uint64_t *size)
	119	{
a78ce05d AK	120	const struct v9fs_inode *v9inode = cookie_netfs_data;
a78ce05d AK	121	*size = i_size_read(&v9inode->vfs_inode);
60e78d2c	122
a78ce05d	123	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get attr %llu", &v9inode->vfs_inode,
60e78d2c AK	124	*size);
	125	}
	126
	127	static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data,
	128	void *buffer, uint16_t buflen)
	129	{
a78ce05d	130	const struct v9fs_inode *v9inode = cookie_netfs_data;
fd2421f5	131	memcpy(buffer, &v9inode->qid.version, sizeof(v9inode->qid.version));
a78ce05d	132	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get aux %u", &v9inode->vfs_inode,
fd2421f5 AK	133	v9inode->qid.version);
fd2421f5 AK	134	return sizeof(v9inode->qid.version);
60e78d2c AK	135	}
	136
	137	static enum
	138	fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
	139	const void *buffer,
	140	uint16_t buflen)
	141	{
a78ce05d	142	const struct v9fs_inode *v9inode = cookie_netfs_data;
60e78d2c	143
fd2421f5	144	if (buflen != sizeof(v9inode->qid.version))
60e78d2c AK	145	return FSCACHE_CHECKAUX_OBSOLETE;
60e78d2c AK	146
fd2421f5 AK	147	if (memcmp(buffer, &v9inode->qid.version,
fd2421f5 AK	148	sizeof(v9inode->qid.version)))
60e78d2c AK	149	return FSCACHE_CHECKAUX_OBSOLETE;
	150
	151	return FSCACHE_CHECKAUX_OKAY;
	152	}
	153
	154	static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data)
	155	{
a78ce05d	156	struct v9fs_inode *v9inode = cookie_netfs_data;
60e78d2c AK	157	struct pagevec pvec;
	158	pgoff_t first;
	159	int loop, nr_pages;
	160
	161	pagevec_init(&pvec, 0);
	162	first = 0;
	163
	164	for (;;) {
a78ce05d	165	nr_pages = pagevec_lookup(&pvec, v9inode->vfs_inode.i_mapping,
60e78d2c AK	166	first,
	167	PAGEVEC_SIZE - pagevec_count(&pvec));
	168	if (!nr_pages)
	169	break;
	170
	171	for (loop = 0; loop < nr_pages; loop++)
	172	ClearPageFsCache(pvec.pages[loop]);
	173
	174	first = pvec.pages[nr_pages - 1]->index + 1;
	175
	176	pvec.nr = nr_pages;
	177	pagevec_release(&pvec);
	178	cond_resched();
	179	}
	180	}
	181
	182	const struct fscache_cookie_def v9fs_cache_inode_index_def = {
	183	.name = "9p.inode",
	184	.type = FSCACHE_COOKIE_TYPE_DATAFILE,
	185	.get_key = v9fs_cache_inode_get_key,
	186	.get_attr = v9fs_cache_inode_get_attr,
	187	.get_aux = v9fs_cache_inode_get_aux,
	188	.check_aux = v9fs_cache_inode_check_aux,
	189	.now_uncached = v9fs_cache_inode_now_uncached,
	190	};
	191
	192	void v9fs_cache_inode_get_cookie(struct inode *inode)
	193	{
a78ce05d	194	struct v9fs_inode *v9inode;
60e78d2c AK	195	struct v9fs_session_info *v9ses;
	196
	197	if (!S_ISREG(inode->i_mode))
	198	return;
	199
a78ce05d AK	200	v9inode = V9FS_I(inode);
a78ce05d AK	201	if (v9inode->fscache)
60e78d2c AK	202	return;
	203
	204	v9ses = v9fs_inode2v9ses(inode);
a78ce05d	205	v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
60e78d2c	206	&v9fs_cache_inode_index_def,
a78ce05d	207	v9inode);
60e78d2c AK	208
60e78d2c AK	209	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get cookie %p", inode,
a78ce05d	210	v9inode->fscache);
60e78d2c AK	211	}
	212
	213	void v9fs_cache_inode_put_cookie(struct inode *inode)
	214	{
a78ce05d	215	struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c	216
a78ce05d	217	if (!v9inode->fscache)
60e78d2c AK	218	return;
60e78d2c AK	219	P9_DPRINTK(P9_DEBUG_FSC, "inode %p put cookie %p", inode,
a78ce05d	220	v9inode->fscache);
60e78d2c	221
a78ce05d AK	222	fscache_relinquish_cookie(v9inode->fscache, 0);
a78ce05d AK	223	v9inode->fscache = NULL;
60e78d2c AK	224	}
	225
	226	void v9fs_cache_inode_flush_cookie(struct inode *inode)
	227	{
a78ce05d	228	struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c	229
a78ce05d	230	if (!v9inode->fscache)
60e78d2c AK	231	return;
60e78d2c AK	232	P9_DPRINTK(P9_DEBUG_FSC, "inode %p flush cookie %p", inode,
a78ce05d	233	v9inode->fscache);
60e78d2c	234
a78ce05d AK	235	fscache_relinquish_cookie(v9inode->fscache, 1);
a78ce05d AK	236	v9inode->fscache = NULL;
60e78d2c AK	237	}
	238
	239	void v9fs_cache_inode_set_cookie(struct inode inode, struct file filp)
	240	{
a78ce05d	241	struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c AK	242	struct p9_fid *fid;
60e78d2c AK	243
a78ce05d	244	if (!v9inode->fscache)
60e78d2c AK	245	return;
60e78d2c AK	246
a78ce05d	247	spin_lock(&v9inode->fscache_lock);
60e78d2c AK	248	fid = filp->private_data;
	249	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
	250	v9fs_cache_inode_flush_cookie(inode);
	251	else
	252	v9fs_cache_inode_get_cookie(inode);
	253
a78ce05d	254	spin_unlock(&v9inode->fscache_lock);
60e78d2c AK	255	}
	256
	257	void v9fs_cache_inode_reset_cookie(struct inode *inode)
	258	{
a78ce05d	259	struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c AK	260	struct v9fs_session_info *v9ses;
	261	struct fscache_cookie *old;
	262
a78ce05d	263	if (!v9inode->fscache)
60e78d2c AK	264	return;
60e78d2c AK	265
a78ce05d	266	old = v9inode->fscache;
60e78d2c	267
a78ce05d AK	268	spin_lock(&v9inode->fscache_lock);
a78ce05d AK	269	fscache_relinquish_cookie(v9inode->fscache, 1);
60e78d2c AK	270
60e78d2c AK	271	v9ses = v9fs_inode2v9ses(inode);
a78ce05d	272	v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
60e78d2c	273	&v9fs_cache_inode_index_def,
a78ce05d	274	v9inode);
60e78d2c	275	P9_DPRINTK(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p",
a78ce05d	276	inode, old, v9inode->fscache);
60e78d2c	277
a78ce05d	278	spin_unlock(&v9inode->fscache_lock);
60e78d2c AK	279	}
	280
	281	int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
	282	{
	283	struct inode *inode = page->mapping->host;
a78ce05d	284	struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c	285
a78ce05d	286	BUG_ON(!v9inode->fscache);
60e78d2c	287
a78ce05d	288	return fscache_maybe_release_page(v9inode->fscache, page, gfp);
60e78d2c AK	289	}
	290
	291	void __v9fs_fscache_invalidate_page(struct page *page)
	292	{
	293	struct inode *inode = page->mapping->host;
a78ce05d	294	struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c	295
a78ce05d	296	BUG_ON(!v9inode->fscache);
60e78d2c AK	297
60e78d2c AK	298	if (PageFsCache(page)) {
a78ce05d	299	fscache_wait_on_page_write(v9inode->fscache, page);
60e78d2c	300	BUG_ON(!PageLocked(page));
a78ce05d	301	fscache_uncache_page(v9inode->fscache, page);
60e78d2c AK	302	}
	303	}
	304
	305	static void v9fs_vfs_readpage_complete(struct page page, void data,
	306	int error)
	307	{
	308	if (!error)
	309	SetPageUptodate(page);
	310
	311	unlock_page(page);
	312	}
	313
	314	/**
	315	* __v9fs_readpage_from_fscache - read a page from cache
	316	*
	317	* Returns 0 if the pages are in cache and a BIO is submitted,
	318	* 1 if the pages are not in cache and -error otherwise.
	319	*/
	320
	321	int __v9fs_readpage_from_fscache(struct inode inode, struct page page)
	322	{
	323	int ret;
a78ce05d	324	const struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c AK	325
60e78d2c AK	326	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
a78ce05d	327	if (!v9inode->fscache)
60e78d2c AK	328	return -ENOBUFS;
60e78d2c AK	329
a78ce05d	330	ret = fscache_read_or_alloc_page(v9inode->fscache,
60e78d2c AK	331	page,
	332	v9fs_vfs_readpage_complete,
	333	NULL,
	334	GFP_KERNEL);
	335	switch (ret) {
	336	case -ENOBUFS:
	337	case -ENODATA:
	338	P9_DPRINTK(P9_DEBUG_FSC, "page/inode not in cache %d", ret);
	339	return 1;
	340	case 0:
	341	P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted");
	342	return ret;
	343	default:
	344	P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret);
	345	return ret;
	346	}
	347	}
	348
	349	/**
	350	* __v9fs_readpages_from_fscache - read multiple pages from cache
	351	*
	352	* Returns 0 if the pages are in cache and a BIO is submitted,
	353	* 1 if the pages are not in cache and -error otherwise.
	354	*/
	355
	356	int __v9fs_readpages_from_fscache(struct inode *inode,
	357	struct address_space *mapping,
	358	struct list_head *pages,
	359	unsigned *nr_pages)
	360	{
	361	int ret;
a78ce05d	362	const struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c AK	363
60e78d2c AK	364	P9_DPRINTK(P9_DEBUG_FSC, "inode %p pages %u", inode, *nr_pages);
a78ce05d	365	if (!v9inode->fscache)
60e78d2c AK	366	return -ENOBUFS;
60e78d2c AK	367
a78ce05d	368	ret = fscache_read_or_alloc_pages(v9inode->fscache,
60e78d2c AK	369	mapping, pages, nr_pages,
	370	v9fs_vfs_readpage_complete,
	371	NULL,
	372	mapping_gfp_mask(mapping));
	373	switch (ret) {
	374	case -ENOBUFS:
	375	case -ENODATA:
	376	P9_DPRINTK(P9_DEBUG_FSC, "pages/inodes not in cache %d", ret);
	377	return 1;
	378	case 0:
	379	BUG_ON(!list_empty(pages));
	380	BUG_ON(*nr_pages != 0);
	381	P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted");
	382	return ret;
	383	default:
	384	P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret);
	385	return ret;
	386	}
	387	}
	388
	389	/**
	390	* __v9fs_readpage_to_fscache - write a page to the cache
	391	*
	392	*/
	393
	394	void __v9fs_readpage_to_fscache(struct inode inode, struct page page)
	395	{
	396	int ret;
a78ce05d	397	const struct v9fs_inode *v9inode = V9FS_I(inode);
60e78d2c AK	398
60e78d2c AK	399	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
a78ce05d	400	ret = fscache_write_page(v9inode->fscache, page, GFP_KERNEL);
60e78d2c AK	401	P9_DPRINTK(P9_DEBUG_FSC, "ret = %d", ret);
	402	if (ret != 0)
	403	v9fs_uncache_page(inode, page);
	404	}
2efda799 AK	405
	406	/*
	407	* wait for a page to complete writing to the cache
	408	*/
	409	void __v9fs_fscache_wait_on_page_write(struct inode inode, struct page page)
	410	{
a78ce05d	411	const struct v9fs_inode *v9inode = V9FS_I(inode);
2efda799 AK	412	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
2efda799 AK	413	if (PageFsCache(page))
a78ce05d	414	fscache_wait_on_page_write(v9inode->fscache, page);
2efda799	415	}