[mirror_ubuntu-jammy-kernel.git] / fs / ceph / cache.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Ceph cache definitions.
 *
 *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
 *  Written by Milosz Tanski (milosz@adfin.com)
 */

#include "super.h"
#include "cache.h"

struct ceph_aux_inode {
	u64 	version;
	u64	mtime_sec;
	u64	mtime_nsec;
};

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_sec = inode->i_mtime.tv_sec;
	aux.mtime_nsec = inode->i_mtime.tv_nsec;

	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_sec = inode->i_mtime.tv_sec;
		aux.mtime_nsec = inode->i_mtime.tv_nsec;
		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
1f327613	1	// SPDX-License-Identifier: GPL-2.0-only
99ccbd22 MT	2	/*
	3	* Ceph cache definitions.
	4	*
	5	* Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
	6	* Written by Milosz Tanski (milosz@adfin.com)
99ccbd22 MT	7	*/
99ccbd22 MT	8
99ccbd22 MT	9	#include "super.h"
	10	#include "cache.h"
	11
	12	struct ceph_aux_inode {
9bbeab41 AB	13	u64 version;
	14	u64 mtime_sec;
	15	u64 mtime_nsec;
99ccbd22 MT	16	};
	17
	18	struct fscache_netfs ceph_cache_netfs = {
	19	.name = "ceph",
	20	.version = 0,
	21	};
	22
1d8f8360 YZ	23	static DEFINE_MUTEX(ceph_fscache_lock);
	24	static LIST_HEAD(ceph_fscache_list);
	25
	26	struct ceph_fscache_entry {
	27	struct list_head list;
	28	struct fscache_cookie *fscache;
1d8f8360	29	size_t uniq_len;
402cb8dd DH	30	/* The following members must be last */
402cb8dd DH	31	struct ceph_fsid fsid;
1d8f8360 YZ	32	char uniquifier[0];
	33	};
	34
99ccbd22 MT	35	static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
	36	.name = "CEPH.fsid",
	37	.type = FSCACHE_COOKIE_TYPE_INDEX,
99ccbd22 MT	38	};
99ccbd22 MT	39
57a35dfb	40	int __init ceph_fscache_register(void)
99ccbd22 MT	41	{
	42	return fscache_register_netfs(&ceph_cache_netfs);
	43	}
	44
971f0bde	45	void ceph_fscache_unregister(void)
99ccbd22 MT	46	{
	47	fscache_unregister_netfs(&ceph_cache_netfs);
	48	}
	49
	50	int ceph_fscache_register_fs(struct ceph_fs_client* fsc)
	51	{
1d8f8360 YZ	52	const struct ceph_fsid *fsid = &fsc->client->fsid;
	53	const char *fscache_uniq = fsc->mount_options->fscache_uniq;
	54	size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0;
	55	struct ceph_fscache_entry *ent;
	56	int err = 0;
	57
	58	mutex_lock(&ceph_fscache_lock);
	59	list_for_each_entry(ent, &ceph_fscache_list, list) {
	60	if (memcmp(&ent->fsid, fsid, sizeof(*fsid)))
	61	continue;
	62	if (ent->uniq_len != uniq_len)
	63	continue;
	64	if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len))
	65	continue;
	66
	67	pr_err("fscache cookie already registered for fsid %pU\n", fsid);
	68	pr_err(" use fsc=%%s mount option to specify a uniquifier\n");
	69	err = -EBUSY;
	70	goto out_unlock;
	71	}
	72
	73	ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL);
	74	if (!ent) {
	75	err = -ENOMEM;
	76	goto out_unlock;
	77	}
	78
402cb8dd DH	79	memcpy(&ent->fsid, fsid, sizeof(*fsid));
	80	if (uniq_len > 0) {
	81	memcpy(&ent->uniquifier, fscache_uniq, uniq_len);
	82	ent->uniq_len = uniq_len;
	83	}
	84
99ccbd22 MT	85	fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
99ccbd22 MT	86	&ceph_fscache_fsid_object_def,
402cb8dd DH	87	&ent->fsid, sizeof(ent->fsid) + uniq_len,
402cb8dd DH	88	NULL, 0,
ee1235a9	89	fsc, 0, true);
99ccbd22	90
1d8f8360	91	if (fsc->fscache) {
1d8f8360 YZ	92	ent->fscache = fsc->fscache;
	93	list_add_tail(&ent->list, &ceph_fscache_list);
	94	} else {
	95	kfree(ent);
	96	pr_err("unable to register fscache cookie for fsid %pU\n",
	97	fsid);
	98	/* all other fs ignore this error */
	99	}
	100	out_unlock:
	101	mutex_unlock(&ceph_fscache_lock);
	102	return err;
99ccbd22 MT	103	}
99ccbd22 MT	104
99ccbd22	105	static enum fscache_checkaux ceph_fscache_inode_check_aux(
ee1235a9 DH	106	void cookie_netfs_data, const void data, uint16_t dlen,
ee1235a9 DH	107	loff_t object_size)
99ccbd22 MT	108	{
	109	struct ceph_aux_inode aux;
	110	struct ceph_inode_info* ci = cookie_netfs_data;
	111	struct inode* inode = &ci->vfs_inode;
	112
ee1235a9 DH	113	if (dlen != sizeof(aux) \|\|
ee1235a9 DH	114	i_size_read(inode) != object_size)
99ccbd22 MT	115	return FSCACHE_CHECKAUX_OBSOLETE;
	116
	117	memset(&aux, 0, sizeof(aux));
f6973c09	118	aux.version = ci->i_version;
9bbeab41 AB	119	aux.mtime_sec = inode->i_mtime.tv_sec;
9bbeab41 AB	120	aux.mtime_nsec = inode->i_mtime.tv_nsec;
99ccbd22 MT	121
	122	if (memcmp(data, &aux, sizeof(aux)) != 0)
	123	return FSCACHE_CHECKAUX_OBSOLETE;
	124
4c069a58	125	dout("ceph inode 0x%p cached okay\n", ci);
99ccbd22 MT	126	return FSCACHE_CHECKAUX_OKAY;
	127	}
	128
99ccbd22 MT	129	static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
	130	.name = "CEPH.inode",
	131	.type = FSCACHE_COOKIE_TYPE_DATAFILE,
99ccbd22	132	.check_aux = ceph_fscache_inode_check_aux,
99ccbd22 MT	133	};
99ccbd22 MT	134
46b59b2b	135	void ceph_fscache_register_inode_cookie(struct inode *inode)
99ccbd22	136	{
46b59b2b YZ	137	struct ceph_inode_info *ci = ceph_inode(inode);
46b59b2b YZ	138	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
402cb8dd	139	struct ceph_aux_inode aux;
99ccbd22 MT	140
99ccbd22 MT	141	/* No caching for filesystem */
d37b1d99	142	if (!fsc->fscache)
99ccbd22 MT	143	return;
	144
	145	/* Only cache for regular files that are read only */
46b59b2b	146	if (!S_ISREG(inode->i_mode))
99ccbd22 MT	147	return;
99ccbd22 MT	148
46b59b2b YZ	149	inode_lock_nested(inode, I_MUTEX_CHILD);
46b59b2b YZ	150	if (!ci->fscache) {
402cb8dd DH	151	memset(&aux, 0, sizeof(aux));
402cb8dd DH	152	aux.version = ci->i_version;
9bbeab41 AB	153	aux.mtime_sec = inode->i_mtime.tv_sec;
9bbeab41 AB	154	aux.mtime_nsec = inode->i_mtime.tv_nsec;
46b59b2b	155	ci->fscache = fscache_acquire_cookie(fsc->fscache,
402cb8dd DH	156	&ceph_fscache_inode_object_def,
	157	&ci->i_vino, sizeof(ci->i_vino),
	158	&aux, sizeof(aux),
ee1235a9	159	ci, i_size_read(inode), false);
46b59b2b	160	}
5955102c	161	inode_unlock(inode);
99ccbd22 MT	162	}
	163
	164	void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
	165	{
	166	struct fscache_cookie* cookie;
	167
	168	if ((cookie = ci->fscache) == NULL)
	169	return;
	170
	171	ci->fscache = NULL;
	172
	173	fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
402cb8dd	174	fscache_relinquish_cookie(cookie, &ci->i_vino, false);
99ccbd22 MT	175	}
99ccbd22 MT	176
46b59b2b YZ	177	static bool ceph_fscache_can_enable(void *data)
	178	{
	179	struct inode *inode = data;
	180	return !inode_is_open_for_write(inode);
	181	}
	182
	183	void ceph_fscache_file_set_cookie(struct inode inode, struct file filp)
	184	{
	185	struct ceph_inode_info *ci = ceph_inode(inode);
	186
	187	if (!fscache_cookie_valid(ci->fscache))
	188	return;
	189
	190	if (inode_is_open_for_write(inode)) {
	191	dout("fscache_file_set_cookie %p %p disabling cache\n",
	192	inode, filp);
402cb8dd	193	fscache_disable_cookie(ci->fscache, &ci->i_vino, false);
46b59b2b YZ	194	fscache_uncache_all_inode_pages(ci->fscache, inode);
46b59b2b YZ	195	} else {
ee1235a9	196	fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode),
402cb8dd	197	ceph_fscache_can_enable, inode);
46b59b2b	198	if (fscache_cookie_enabled(ci->fscache)) {
0fbc5360	199	dout("fscache_file_set_cookie %p %p enabling cache\n",
46b59b2b YZ	200	inode, filp);
	201	}
	202	}
	203	}
	204
dd2bc473	205	static void ceph_readpage_from_fscache_complete(struct page page, void data, int error)
99ccbd22 MT	206	{
	207	if (!error)
	208	SetPageUptodate(page);
	209
	210	unlock_page(page);
	211	}
	212
3b33f692	213	static inline bool cache_valid(struct ceph_inode_info *ci)
99ccbd22	214	{
f7f7e7a0	215	return ci->i_fscache_gen == ci->i_rdcache_gen;
99ccbd22 MT	216	}
	217
	218
	219	/* Atempt to read from the fscache,
	220	*
	221	* This function is called from the readpage_nounlock context. DO NOT attempt to
	222	* unlock the page here (or in the callback).
	223	*/
	224	int ceph_readpage_from_fscache(struct inode inode, struct page page)
	225	{
	226	struct ceph_inode_info *ci = ceph_inode(inode);
	227	int ret;
	228
	229	if (!cache_valid(ci))
	230	return -ENOBUFS;
	231
	232	ret = fscache_read_or_alloc_page(ci->fscache, page,
dd2bc473	233	ceph_readpage_from_fscache_complete, NULL,
99ccbd22 MT	234	GFP_KERNEL);
	235
	236	switch (ret) {
	237	case 0: /* Page found */
	238	dout("page read submitted\n");
	239	return 0;
	240	case -ENOBUFS: /* Pages were not found, and can't be */
	241	case -ENODATA: /* Pages were not found */
	242	dout("page/inode not in cache\n");
	243	return ret;
	244	default:
	245	dout("%s: unknown error ret = %i\n", __func__, ret);
	246	return ret;
	247	}
	248	}
	249
	250	int ceph_readpages_from_fscache(struct inode *inode,
	251	struct address_space *mapping,
	252	struct list_head *pages,
	253	unsigned *nr_pages)
	254	{
	255	struct ceph_inode_info *ci = ceph_inode(inode);
	256	int ret;
	257
	258	if (!cache_valid(ci))
	259	return -ENOBUFS;
	260
	261	ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
dd2bc473	262	ceph_readpage_from_fscache_complete,
99ccbd22 MT	263	NULL, mapping_gfp_mask(mapping));
	264
	265	switch (ret) {
	266	case 0: /* All pages found */
	267	dout("all-page read submitted\n");
	268	return 0;
	269	case -ENOBUFS: /* Some pages were not found, and can't be */
	270	case -ENODATA: /* some pages were not found */
	271	dout("page/inode not in cache\n");
	272	return ret;
	273	default:
	274	dout("%s: unknown error ret = %i\n", __func__, ret);
	275	return ret;
	276	}
	277	}
	278
	279	void ceph_readpage_to_fscache(struct inode inode, struct page page)
	280	{
	281	struct ceph_inode_info *ci = ceph_inode(inode);
	282	int ret;
	283
9b8dd1e8 MT	284	if (!PageFsCache(page))
	285	return;
	286
99ccbd22 MT	287	if (!cache_valid(ci))
	288	return;
	289
ee1235a9 DH	290	ret = fscache_write_page(ci->fscache, page, i_size_read(inode),
ee1235a9 DH	291	GFP_KERNEL);
99ccbd22 MT	292	if (ret)
	293	fscache_uncache_page(ci->fscache, page);
	294	}
	295
	296	void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
	297	{
	298	struct ceph_inode_info *ci = ceph_inode(inode);
	299
ffc79664 MT	300	if (!PageFsCache(page))
	301	return;
	302
99ccbd22 MT	303	fscache_wait_on_page_write(ci->fscache, page);
	304	fscache_uncache_page(ci->fscache, page);
	305	}
	306
	307	void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
	308	{
1d8f8360 YZ	309	if (fscache_cookie_valid(fsc->fscache)) {
	310	struct ceph_fscache_entry *ent;
	311	bool found = false;
	312
	313	mutex_lock(&ceph_fscache_lock);
	314	list_for_each_entry(ent, &ceph_fscache_list, list) {
	315	if (ent->fscache == fsc->fscache) {
	316	list_del(&ent->list);
	317	kfree(ent);
	318	found = true;
	319	break;
	320	}
	321	}
	322	WARN_ON_ONCE(!found);
	323	mutex_unlock(&ceph_fscache_lock);
	324
402cb8dd	325	__fscache_relinquish_cookie(fsc->fscache, NULL, false);
1d8f8360	326	}
99ccbd22 MT	327	fsc->fscache = NULL;
	328	}
	329
f7f7e7a0 YZ	330	/*
	331	* caller should hold CEPH_CAP_FILE_{RD,CACHE}
	332	*/
	333	void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
99ccbd22	334	{
f7f7e7a0	335	if (cache_valid(ci))
e81568eb MT	336	return;
e81568eb MT	337
f7f7e7a0 YZ	338	/* resue i_truncate_mutex. There should be no pending
	339	* truncate while the caller holds CEPH_CAP_FILE_RD */
	340	mutex_lock(&ci->i_truncate_mutex);
	341	if (!cache_valid(ci)) {
402cb8dd	342	if (fscache_check_consistency(ci->fscache, &ci->i_vino))
f7f7e7a0 YZ	343	fscache_invalidate(ci->fscache);
	344	spin_lock(&ci->i_ceph_lock);
	345	ci->i_fscache_gen = ci->i_rdcache_gen;
	346	spin_unlock(&ci->i_ceph_lock);
99ccbd22	347	}
f7f7e7a0	348	mutex_unlock(&ci->i_truncate_mutex);
99ccbd22	349	}