[linux-2.6-block.git] / fs / ceph / cache.c

/*
 * Ceph cache definitions.
 *
 *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
 *  Written by Milosz Tanski (milosz@adfin.com)
 *
 *  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 "super.h"
#include "cache.h"

struct ceph_aux_inode {
	u64 		version;
	struct timespec	mtime;
};

struct fscache_netfs ceph_cache_netfs = {
	.name		= "ceph",
	.version	= 0,
};

static DEFINE_MUTEX(ceph_fscache_lock);
static LIST_HEAD(ceph_fscache_list);

struct ceph_fscache_entry {
	struct list_head list;
	struct fscache_cookie *fscache;
	size_t uniq_len;
	/* The following members must be last */
	struct ceph_fsid fsid;
	char uniquifier[0];
};

static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
	.name		= "CEPH.fsid",
	.type		= FSCACHE_COOKIE_TYPE_INDEX,
};

int __init ceph_fscache_register(void)
{
	return fscache_register_netfs(&ceph_cache_netfs);
}

void ceph_fscache_unregister(void)
{
	fscache_unregister_netfs(&ceph_cache_netfs);
}

int ceph_fscache_register_fs(struct ceph_fs_client* fsc)
{
	const struct ceph_fsid *fsid = &fsc->client->fsid;
	const char *fscache_uniq = fsc->mount_options->fscache_uniq;
	size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0;
	struct ceph_fscache_entry *ent;
	int err = 0;

	mutex_lock(&ceph_fscache_lock);
	list_for_each_entry(ent, &ceph_fscache_list, list) {
		if (memcmp(&ent->fsid, fsid, sizeof(*fsid)))
			continue;
		if (ent->uniq_len != uniq_len)
			continue;
		if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len))
			continue;

		pr_err("fscache cookie already registered for fsid %pU\n", fsid);
		pr_err("  use fsc=%%s mount option to specify a uniquifier\n");
		err = -EBUSY;
		goto out_unlock;
	}

	ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL);
	if (!ent) {
		err = -ENOMEM;
		goto out_unlock;
	}

	memcpy(&ent->fsid, fsid, sizeof(*fsid));
	if (uniq_len > 0) {
		memcpy(&ent->uniquifier, fscache_uniq, uniq_len);
		ent->uniq_len = uniq_len;
	}

	fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
					      &ceph_fscache_fsid_object_def,
					      &ent->fsid, sizeof(ent->fsid) + uniq_len,
					      NULL, 0,
					      fsc, 0, true);

	if (fsc->fscache) {
		ent->fscache = fsc->fscache;
		list_add_tail(&ent->list, &ceph_fscache_list);
	} else {
		kfree(ent);
		pr_err("unable to register fscache cookie for fsid %pU\n",
		       fsid);
		/* all other fs ignore this error */
	}
out_unlock:
	mutex_unlock(&ceph_fscache_lock);
	return err;
}

static enum fscache_checkaux ceph_fscache_inode_check_aux(
	void *cookie_netfs_data, const void *data, uint16_t dlen,
	loff_t object_size)
{
	struct ceph_aux_inode aux;
	struct ceph_inode_info* ci = cookie_netfs_data;
	struct inode* inode = &ci->vfs_inode;

	if (dlen != sizeof(aux) ||
	    i_size_read(inode) != object_size)
		return FSCACHE_CHECKAUX_OBSOLETE;

	memset(&aux, 0, sizeof(aux));
	aux.version = ci->i_version;
	aux.mtime = inode->i_mtime;

	if (memcmp(data, &aux, sizeof(aux)) != 0)
		return FSCACHE_CHECKAUX_OBSOLETE;

	dout("ceph inode 0x%p cached okay\n", ci);
	return FSCACHE_CHECKAUX_OKAY;
}

static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
	.name		= "CEPH.inode",
	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
	.check_aux	= ceph_fscache_inode_check_aux,
};

void ceph_fscache_register_inode_cookie(struct inode *inode)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
	struct ceph_aux_inode aux;

	/* No caching for filesystem */
	if (!fsc->fscache)
		return;

	/* Only cache for regular files that are read only */
	if (!S_ISREG(inode->i_mode))
		return;

	inode_lock_nested(inode, I_MUTEX_CHILD);
	if (!ci->fscache) {
		memset(&aux, 0, sizeof(aux));
		aux.version = ci->i_version;
		aux.mtime = inode->i_mtime;
		ci->fscache = fscache_acquire_cookie(fsc->fscache,
						     &ceph_fscache_inode_object_def,
						     &ci->i_vino, sizeof(ci->i_vino),
						     &aux, sizeof(aux),
						     ci, i_size_read(inode), false);
	}
	inode_unlock(inode);
}

void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
{
	struct fscache_cookie* cookie;

	if ((cookie = ci->fscache) == NULL)
		return;

	ci->fscache = NULL;

	fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
	fscache_relinquish_cookie(cookie, &ci->i_vino, false);
}

static bool ceph_fscache_can_enable(void *data)
{
	struct inode *inode = data;
	return !inode_is_open_for_write(inode);
}

void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp)
{
	struct ceph_inode_info *ci = ceph_inode(inode);

	if (!fscache_cookie_valid(ci->fscache))
		return;

	if (inode_is_open_for_write(inode)) {
		dout("fscache_file_set_cookie %p %p disabling cache\n",
		     inode, filp);
		fscache_disable_cookie(ci->fscache, &ci->i_vino, false);
		fscache_uncache_all_inode_pages(ci->fscache, inode);
	} else {
		fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode),
				      ceph_fscache_can_enable, inode);
		if (fscache_cookie_enabled(ci->fscache)) {
			dout("fscache_file_set_cookie %p %p enabling cache\n",
			     inode, filp);
		}
	}
}

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

	unlock_page(page);
}

static inline bool cache_valid(struct ceph_inode_info *ci)
{
	return ci->i_fscache_gen == ci->i_rdcache_gen;
}


/* Atempt to read from the fscache,
 *
 * This function is called from the readpage_nounlock context. DO NOT attempt to
 * unlock the page here (or in the callback).
 */
int ceph_readpage_from_fscache(struct inode *inode, struct page *page)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	int ret;

	if (!cache_valid(ci))
		return -ENOBUFS;

	ret = fscache_read_or_alloc_page(ci->fscache, page,
					 ceph_readpage_from_fscache_complete, NULL,
					 GFP_KERNEL);

	switch (ret) {
		case 0: /* Page found */
			dout("page read submitted\n");
			return 0;
		case -ENOBUFS: /* Pages were not found, and can't be */
		case -ENODATA: /* Pages were not found */
			dout("page/inode not in cache\n");
			return ret;
		default:
			dout("%s: unknown error ret = %i\n", __func__, ret);
			return ret;
	}
}

int ceph_readpages_from_fscache(struct inode *inode,
				  struct address_space *mapping,
				  struct list_head *pages,
				  unsigned *nr_pages)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	int ret;

	if (!cache_valid(ci))
		return -ENOBUFS;

	ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
					  ceph_readpage_from_fscache_complete,
					  NULL, mapping_gfp_mask(mapping));

	switch (ret) {
		case 0: /* All pages found */
			dout("all-page read submitted\n");
			return 0;
		case -ENOBUFS: /* Some pages were not found, and can't be */
		case -ENODATA: /* some pages were not found */
			dout("page/inode not in cache\n");
			return ret;
		default:
			dout("%s: unknown error ret = %i\n", __func__, ret);
			return ret;
	}
}

void ceph_readpage_to_fscache(struct inode *inode, struct page *page)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	int ret;

	if (!PageFsCache(page))
		return;

	if (!cache_valid(ci))
		return;

	ret = fscache_write_page(ci->fscache, page, i_size_read(inode),
				 GFP_KERNEL);
	if (ret)
		 fscache_uncache_page(ci->fscache, page);
}

void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
{
	struct ceph_inode_info *ci = ceph_inode(inode);

	if (!PageFsCache(page))
		return;

	fscache_wait_on_page_write(ci->fscache, page);
	fscache_uncache_page(ci->fscache, page);
}

void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
{
	if (fscache_cookie_valid(fsc->fscache)) {
		struct ceph_fscache_entry *ent;
		bool found = false;

		mutex_lock(&ceph_fscache_lock);
		list_for_each_entry(ent, &ceph_fscache_list, list) {
			if (ent->fscache == fsc->fscache) {
				list_del(&ent->list);
				kfree(ent);
				found = true;
				break;
			}
		}
		WARN_ON_ONCE(!found);
		mutex_unlock(&ceph_fscache_lock);

		__fscache_relinquish_cookie(fsc->fscache, NULL, false);
	}
	fsc->fscache = NULL;
}

/*
 * caller should hold CEPH_CAP_FILE_{RD,CACHE}
 */
void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
{
	if (cache_valid(ci))
		return;

	/* resue i_truncate_mutex. There should be no pending
	 * truncate while the caller holds CEPH_CAP_FILE_RD */
	mutex_lock(&ci->i_truncate_mutex);
	if (!cache_valid(ci)) {
		if (fscache_check_consistency(ci->fscache, &ci->i_vino))
			fscache_invalidate(ci->fscache);
		spin_lock(&ci->i_ceph_lock);
		ci->i_fscache_gen = ci->i_rdcache_gen;
		spin_unlock(&ci->i_ceph_lock);
	}
	mutex_unlock(&ci->i_truncate_mutex);
}
Commit	Line	Data
99ccbd22 MT	1	/*
	2	* Ceph cache definitions.
	3	*
	4	* Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
	5	* Written by Milosz Tanski (milosz@adfin.com)
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2
	9	* as published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to:
	18	* Free Software Foundation
	19	* 51 Franklin Street, Fifth Floor
	20	* Boston, MA 02111-1301 USA
	21	*
	22	*/
	23
99ccbd22 MT	24	#include "super.h"
	25	#include "cache.h"
	26
	27	struct ceph_aux_inode {
f6973c09	28	u64 version;
99ccbd22	29	struct timespec mtime;
99ccbd22 MT	30	};
	31
	32	struct fscache_netfs ceph_cache_netfs = {
	33	.name = "ceph",
	34	.version = 0,
	35	};
	36
1d8f8360 YZ	37	static DEFINE_MUTEX(ceph_fscache_lock);
	38	static LIST_HEAD(ceph_fscache_list);
	39
	40	struct ceph_fscache_entry {
	41	struct list_head list;
	42	struct fscache_cookie *fscache;
1d8f8360	43	size_t uniq_len;
402cb8dd DH	44	/* The following members must be last */
402cb8dd DH	45	struct ceph_fsid fsid;
1d8f8360 YZ	46	char uniquifier[0];
	47	};
	48
99ccbd22 MT	49	static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
	50	.name = "CEPH.fsid",
	51	.type = FSCACHE_COOKIE_TYPE_INDEX,
99ccbd22 MT	52	};
99ccbd22 MT	53
57a35dfb	54	int __init ceph_fscache_register(void)
99ccbd22 MT	55	{
	56	return fscache_register_netfs(&ceph_cache_netfs);
	57	}
	58
971f0bde	59	void ceph_fscache_unregister(void)
99ccbd22 MT	60	{
	61	fscache_unregister_netfs(&ceph_cache_netfs);
	62	}
	63
	64	int ceph_fscache_register_fs(struct ceph_fs_client* fsc)
	65	{
1d8f8360 YZ	66	const struct ceph_fsid *fsid = &fsc->client->fsid;
	67	const char *fscache_uniq = fsc->mount_options->fscache_uniq;
	68	size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0;
	69	struct ceph_fscache_entry *ent;
	70	int err = 0;
	71
	72	mutex_lock(&ceph_fscache_lock);
	73	list_for_each_entry(ent, &ceph_fscache_list, list) {
	74	if (memcmp(&ent->fsid, fsid, sizeof(*fsid)))
	75	continue;
	76	if (ent->uniq_len != uniq_len)
	77	continue;
	78	if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len))
	79	continue;
	80
	81	pr_err("fscache cookie already registered for fsid %pU\n", fsid);
	82	pr_err(" use fsc=%%s mount option to specify a uniquifier\n");
	83	err = -EBUSY;
	84	goto out_unlock;
	85	}
	86
	87	ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL);
	88	if (!ent) {
	89	err = -ENOMEM;
	90	goto out_unlock;
	91	}
	92
402cb8dd DH	93	memcpy(&ent->fsid, fsid, sizeof(*fsid));
	94	if (uniq_len > 0) {
	95	memcpy(&ent->uniquifier, fscache_uniq, uniq_len);
	96	ent->uniq_len = uniq_len;
	97	}
	98
99ccbd22 MT	99	fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
99ccbd22 MT	100	&ceph_fscache_fsid_object_def,
402cb8dd DH	101	&ent->fsid, sizeof(ent->fsid) + uniq_len,
402cb8dd DH	102	NULL, 0,
ee1235a9	103	fsc, 0, true);
99ccbd22	104
1d8f8360	105	if (fsc->fscache) {
1d8f8360 YZ	106	ent->fscache = fsc->fscache;
	107	list_add_tail(&ent->list, &ceph_fscache_list);
	108	} else {
	109	kfree(ent);
	110	pr_err("unable to register fscache cookie for fsid %pU\n",
	111	fsid);
	112	/* all other fs ignore this error */
	113	}
	114	out_unlock:
	115	mutex_unlock(&ceph_fscache_lock);
	116	return err;
99ccbd22 MT	117	}
99ccbd22 MT	118
99ccbd22	119	static enum fscache_checkaux ceph_fscache_inode_check_aux(
ee1235a9 DH	120	void cookie_netfs_data, const void data, uint16_t dlen,
ee1235a9 DH	121	loff_t object_size)
99ccbd22 MT	122	{
	123	struct ceph_aux_inode aux;
	124	struct ceph_inode_info* ci = cookie_netfs_data;
	125	struct inode* inode = &ci->vfs_inode;
	126
ee1235a9 DH	127	if (dlen != sizeof(aux) \|\|
ee1235a9 DH	128	i_size_read(inode) != object_size)
99ccbd22 MT	129	return FSCACHE_CHECKAUX_OBSOLETE;
	130
	131	memset(&aux, 0, sizeof(aux));
f6973c09	132	aux.version = ci->i_version;
99ccbd22	133	aux.mtime = inode->i_mtime;
99ccbd22 MT	134
	135	if (memcmp(data, &aux, sizeof(aux)) != 0)
	136	return FSCACHE_CHECKAUX_OBSOLETE;
	137
4c069a58	138	dout("ceph inode 0x%p cached okay\n", ci);
99ccbd22 MT	139	return FSCACHE_CHECKAUX_OKAY;
	140	}
	141
99ccbd22 MT	142	static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
	143	.name = "CEPH.inode",
	144	.type = FSCACHE_COOKIE_TYPE_DATAFILE,
99ccbd22	145	.check_aux = ceph_fscache_inode_check_aux,
99ccbd22 MT	146	};
99ccbd22 MT	147
46b59b2b	148	void ceph_fscache_register_inode_cookie(struct inode *inode)
99ccbd22	149	{
46b59b2b YZ	150	struct ceph_inode_info *ci = ceph_inode(inode);
46b59b2b YZ	151	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
402cb8dd	152	struct ceph_aux_inode aux;
99ccbd22 MT	153
99ccbd22 MT	154	/* No caching for filesystem */
d37b1d99	155	if (!fsc->fscache)
99ccbd22 MT	156	return;
	157
	158	/* Only cache for regular files that are read only */
46b59b2b	159	if (!S_ISREG(inode->i_mode))
99ccbd22 MT	160	return;
99ccbd22 MT	161
46b59b2b YZ	162	inode_lock_nested(inode, I_MUTEX_CHILD);
46b59b2b YZ	163	if (!ci->fscache) {
402cb8dd DH	164	memset(&aux, 0, sizeof(aux));
	165	aux.version = ci->i_version;
	166	aux.mtime = inode->i_mtime;
46b59b2b	167	ci->fscache = fscache_acquire_cookie(fsc->fscache,
402cb8dd DH	168	&ceph_fscache_inode_object_def,
	169	&ci->i_vino, sizeof(ci->i_vino),
	170	&aux, sizeof(aux),
ee1235a9	171	ci, i_size_read(inode), false);
46b59b2b	172	}
5955102c	173	inode_unlock(inode);
99ccbd22 MT	174	}
	175
	176	void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
	177	{
	178	struct fscache_cookie* cookie;
	179
	180	if ((cookie = ci->fscache) == NULL)
	181	return;
	182
	183	ci->fscache = NULL;
	184
	185	fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
402cb8dd	186	fscache_relinquish_cookie(cookie, &ci->i_vino, false);
99ccbd22 MT	187	}
99ccbd22 MT	188
46b59b2b YZ	189	static bool ceph_fscache_can_enable(void *data)
	190	{
	191	struct inode *inode = data;
	192	return !inode_is_open_for_write(inode);
	193	}
	194
	195	void ceph_fscache_file_set_cookie(struct inode inode, struct file filp)
	196	{
	197	struct ceph_inode_info *ci = ceph_inode(inode);
	198
	199	if (!fscache_cookie_valid(ci->fscache))
	200	return;
	201
	202	if (inode_is_open_for_write(inode)) {
	203	dout("fscache_file_set_cookie %p %p disabling cache\n",
	204	inode, filp);
402cb8dd	205	fscache_disable_cookie(ci->fscache, &ci->i_vino, false);
46b59b2b YZ	206	fscache_uncache_all_inode_pages(ci->fscache, inode);
46b59b2b YZ	207	} else {
ee1235a9	208	fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode),
402cb8dd	209	ceph_fscache_can_enable, inode);
46b59b2b	210	if (fscache_cookie_enabled(ci->fscache)) {
0fbc5360	211	dout("fscache_file_set_cookie %p %p enabling cache\n",
46b59b2b YZ	212	inode, filp);
	213	}
	214	}
	215	}
	216
dd2bc473	217	static void ceph_readpage_from_fscache_complete(struct page page, void data, int error)
99ccbd22 MT	218	{
	219	if (!error)
	220	SetPageUptodate(page);
	221
	222	unlock_page(page);
	223	}
	224
3b33f692	225	static inline bool cache_valid(struct ceph_inode_info *ci)
99ccbd22	226	{
f7f7e7a0	227	return ci->i_fscache_gen == ci->i_rdcache_gen;
99ccbd22 MT	228	}
	229
	230
	231	/* Atempt to read from the fscache,
	232	*
	233	* This function is called from the readpage_nounlock context. DO NOT attempt to
	234	* unlock the page here (or in the callback).
	235	*/
	236	int ceph_readpage_from_fscache(struct inode inode, struct page page)
	237	{
	238	struct ceph_inode_info *ci = ceph_inode(inode);
	239	int ret;
	240
	241	if (!cache_valid(ci))
	242	return -ENOBUFS;
	243
	244	ret = fscache_read_or_alloc_page(ci->fscache, page,
dd2bc473	245	ceph_readpage_from_fscache_complete, NULL,
99ccbd22 MT	246	GFP_KERNEL);
	247
	248	switch (ret) {
	249	case 0: /* Page found */
	250	dout("page read submitted\n");
	251	return 0;
	252	case -ENOBUFS: /* Pages were not found, and can't be */
	253	case -ENODATA: /* Pages were not found */
	254	dout("page/inode not in cache\n");
	255	return ret;
	256	default:
	257	dout("%s: unknown error ret = %i\n", __func__, ret);
	258	return ret;
	259	}
	260	}
	261
	262	int ceph_readpages_from_fscache(struct inode *inode,
	263	struct address_space *mapping,
	264	struct list_head *pages,
	265	unsigned *nr_pages)
	266	{
	267	struct ceph_inode_info *ci = ceph_inode(inode);
	268	int ret;
	269
	270	if (!cache_valid(ci))
	271	return -ENOBUFS;
	272
	273	ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
dd2bc473	274	ceph_readpage_from_fscache_complete,
99ccbd22 MT	275	NULL, mapping_gfp_mask(mapping));
	276
	277	switch (ret) {
	278	case 0: /* All pages found */
	279	dout("all-page read submitted\n");
	280	return 0;
	281	case -ENOBUFS: /* Some pages were not found, and can't be */
	282	case -ENODATA: /* some pages were not found */
	283	dout("page/inode not in cache\n");
	284	return ret;
	285	default:
	286	dout("%s: unknown error ret = %i\n", __func__, ret);
	287	return ret;
	288	}
	289	}
	290
	291	void ceph_readpage_to_fscache(struct inode inode, struct page page)
	292	{
	293	struct ceph_inode_info *ci = ceph_inode(inode);
	294	int ret;
	295
9b8dd1e8 MT	296	if (!PageFsCache(page))
	297	return;
	298
99ccbd22 MT	299	if (!cache_valid(ci))
	300	return;
	301
ee1235a9 DH	302	ret = fscache_write_page(ci->fscache, page, i_size_read(inode),
ee1235a9 DH	303	GFP_KERNEL);
99ccbd22 MT	304	if (ret)
	305	fscache_uncache_page(ci->fscache, page);
	306	}
	307
	308	void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
	309	{
	310	struct ceph_inode_info *ci = ceph_inode(inode);
	311
ffc79664 MT	312	if (!PageFsCache(page))
	313	return;
	314
99ccbd22 MT	315	fscache_wait_on_page_write(ci->fscache, page);
	316	fscache_uncache_page(ci->fscache, page);
	317	}
	318
	319	void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
	320	{
1d8f8360 YZ	321	if (fscache_cookie_valid(fsc->fscache)) {
	322	struct ceph_fscache_entry *ent;
	323	bool found = false;
	324
	325	mutex_lock(&ceph_fscache_lock);
	326	list_for_each_entry(ent, &ceph_fscache_list, list) {
	327	if (ent->fscache == fsc->fscache) {
	328	list_del(&ent->list);
	329	kfree(ent);
	330	found = true;
	331	break;
	332	}
	333	}
	334	WARN_ON_ONCE(!found);
	335	mutex_unlock(&ceph_fscache_lock);
	336
402cb8dd	337	__fscache_relinquish_cookie(fsc->fscache, NULL, false);
1d8f8360	338	}
99ccbd22 MT	339	fsc->fscache = NULL;
	340	}
	341
f7f7e7a0 YZ	342	/*
	343	* caller should hold CEPH_CAP_FILE_{RD,CACHE}
	344	*/
	345	void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
99ccbd22	346	{
f7f7e7a0	347	if (cache_valid(ci))
e81568eb MT	348	return;
e81568eb MT	349
f7f7e7a0 YZ	350	/* resue i_truncate_mutex. There should be no pending
	351	* truncate while the caller holds CEPH_CAP_FILE_RD */
	352	mutex_lock(&ci->i_truncate_mutex);
	353	if (!cache_valid(ci)) {
402cb8dd	354	if (fscache_check_consistency(ci->fscache, &ci->i_vino))
f7f7e7a0 YZ	355	fscache_invalidate(ci->fscache);
	356	spin_lock(&ci->i_ceph_lock);
	357	ci->i_fscache_gen = ci->i_rdcache_gen;
	358	spin_unlock(&ci->i_ceph_lock);
99ccbd22	359	}
f7f7e7a0	360	mutex_unlock(&ci->i_truncate_mutex);
99ccbd22	361	}