[linux.git] / fs / nfs / fscache.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* NFS filesystem cache interface
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/in6.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/iversion.h>
#include <linux/xarray.h>
#include <linux/fscache.h>
#include <linux/netfs.h>

#include "internal.h"
#include "iostat.h"
#include "fscache.h"
#include "nfstrace.h"

#define NFS_MAX_KEY_LEN 1000

static bool nfs_append_int(char *key, int *_len, unsigned long long x)
{
	if (*_len > NFS_MAX_KEY_LEN)
		return false;
	if (x == 0)
		key[(*_len)++] = ',';
	else
		*_len += sprintf(key + *_len, ",%llx", x);
	return true;
}

/*
 * Get the per-client index cookie for an NFS client if the appropriate mount
 * flag was set
 * - We always try and get an index cookie for the client, but get filehandle
 *   cookies on a per-superblock basis, depending on the mount flags
 */
static bool nfs_fscache_get_client_key(struct nfs_client *clp,
				       char *key, int *_len)
{
	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr;
	const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr;

	*_len += snprintf(key + *_len, NFS_MAX_KEY_LEN - *_len,
			  ",%u.%u,%x",
			  clp->rpc_ops->version,
			  clp->cl_minorversion,
			  clp->cl_addr.ss_family);

	switch (clp->cl_addr.ss_family) {
	case AF_INET:
		if (!nfs_append_int(key, _len, sin->sin_port) ||
		    !nfs_append_int(key, _len, sin->sin_addr.s_addr))
			return false;
		return true;

	case AF_INET6:
		if (!nfs_append_int(key, _len, sin6->sin6_port) ||
		    !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[0]) ||
		    !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[1]) ||
		    !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[2]) ||
		    !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[3]))
			return false;
		return true;

	default:
		printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
		       clp->cl_addr.ss_family);
		return false;
	}
}

/*
 * Get the cache cookie for an NFS superblock.
 *
 * The default uniquifier is just an empty string, but it may be overridden
 * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent
 * superblock across an automount point of some nature.
 */
int nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen)
{
	struct fscache_volume *vcookie;
	struct nfs_server *nfss = NFS_SB(sb);
	unsigned int len = 3;
	char *key;

	if (uniq) {
		nfss->fscache_uniq = kmemdup_nul(uniq, ulen, GFP_KERNEL);
		if (!nfss->fscache_uniq)
			return -ENOMEM;
	}

	key = kmalloc(NFS_MAX_KEY_LEN + 24, GFP_KERNEL);
	if (!key)
		return -ENOMEM;

	memcpy(key, "nfs", 3);
	if (!nfs_fscache_get_client_key(nfss->nfs_client, key, &len) ||
	    !nfs_append_int(key, &len, nfss->fsid.major) ||
	    !nfs_append_int(key, &len, nfss->fsid.minor) ||
	    !nfs_append_int(key, &len, sb->s_flags & NFS_SB_MASK) ||
	    !nfs_append_int(key, &len, nfss->flags) ||
	    !nfs_append_int(key, &len, nfss->rsize) ||
	    !nfs_append_int(key, &len, nfss->wsize) ||
	    !nfs_append_int(key, &len, nfss->acregmin) ||
	    !nfs_append_int(key, &len, nfss->acregmax) ||
	    !nfs_append_int(key, &len, nfss->acdirmin) ||
	    !nfs_append_int(key, &len, nfss->acdirmax) ||
	    !nfs_append_int(key, &len, nfss->client->cl_auth->au_flavor))
		goto out;

	if (ulen > 0) {
		if (ulen > NFS_MAX_KEY_LEN - len)
			goto out;
		key[len++] = ',';
		memcpy(key + len, uniq, ulen);
		len += ulen;
	}
	key[len] = 0;

	/* create a cache index for looking up filehandles */
	vcookie = fscache_acquire_volume(key,
					 NULL, /* preferred_cache */
					 NULL, 0 /* coherency_data */);
	if (IS_ERR(vcookie)) {
		if (vcookie != ERR_PTR(-EBUSY)) {
			kfree(key);
			return PTR_ERR(vcookie);
		}
		pr_err("NFS: Cache volume key already in use (%s)\n", key);
		vcookie = NULL;
	}
	nfss->fscache = vcookie;

out:
	kfree(key);
	return 0;
}

/*
 * release a per-superblock cookie
 */
void nfs_fscache_release_super_cookie(struct super_block *sb)
{
	struct nfs_server *nfss = NFS_SB(sb);

	fscache_relinquish_volume(nfss->fscache, NULL, false);
	nfss->fscache = NULL;
	kfree(nfss->fscache_uniq);
}

/*
 * Initialise the per-inode cache cookie pointer for an NFS inode.
 */
void nfs_fscache_init_inode(struct inode *inode)
{
	struct nfs_fscache_inode_auxdata auxdata;
	struct nfs_server *nfss = NFS_SERVER(inode);
	struct nfs_inode *nfsi = NFS_I(inode);

	netfs_inode(inode)->cache = NULL;
	if (!(nfss->fscache && S_ISREG(inode->i_mode)))
		return;

	nfs_fscache_update_auxdata(&auxdata, inode);

	netfs_inode(inode)->cache = fscache_acquire_cookie(
					       nfss->fscache,
					       0,
					       nfsi->fh.data, /* index_key */
					       nfsi->fh.size,
					       &auxdata,      /* aux_data */
					       sizeof(auxdata),
					       i_size_read(inode));

	if (netfs_inode(inode)->cache)
		mapping_set_release_always(inode->i_mapping);
}

/*
 * Release a per-inode cookie.
 */
void nfs_fscache_clear_inode(struct inode *inode)
{
	fscache_relinquish_cookie(netfs_i_cookie(netfs_inode(inode)), false);
	netfs_inode(inode)->cache = NULL;
}

/*
 * Enable or disable caching for a file that is being opened as appropriate.
 * The cookie is allocated when the inode is initialised, but is not enabled at
 * that time.  Enablement is deferred to file-open time to avoid stat() and
 * access() thrashing the cache.
 *
 * For now, with NFS, only regular files that are open read-only will be able
 * to use the cache.
 *
 * We enable the cache for an inode if we open it read-only and it isn't
 * currently open for writing.  We disable the cache if the inode is open
 * write-only.
 *
 * The caller uses the file struct to pin i_writecount on the inode before
 * calling us when a file is opened for writing, so we can make use of that.
 *
 * Note that this may be invoked multiple times in parallel by parallel
 * nfs_open() functions.
 */
void nfs_fscache_open_file(struct inode *inode, struct file *filp)
{
	struct nfs_fscache_inode_auxdata auxdata;
	struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
	bool open_for_write = inode_is_open_for_write(inode);

	if (!fscache_cookie_valid(cookie))
		return;

	fscache_use_cookie(cookie, open_for_write);
	if (open_for_write) {
		nfs_fscache_update_auxdata(&auxdata, inode);
		fscache_invalidate(cookie, &auxdata, i_size_read(inode),
				   FSCACHE_INVAL_DIO_WRITE);
	}
}
EXPORT_SYMBOL_GPL(nfs_fscache_open_file);

void nfs_fscache_release_file(struct inode *inode, struct file *filp)
{
	struct nfs_fscache_inode_auxdata auxdata;
	struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
	loff_t i_size = i_size_read(inode);

	nfs_fscache_update_auxdata(&auxdata, inode);
	fscache_unuse_cookie(cookie, &auxdata, &i_size);
}

int nfs_netfs_read_folio(struct file *file, struct folio *folio)
{
	if (!netfs_inode(folio_inode(folio))->cache)
		return -ENOBUFS;

	return netfs_read_folio(file, folio);
}

int nfs_netfs_readahead(struct readahead_control *ractl)
{
	struct inode *inode = ractl->mapping->host;

	if (!netfs_inode(inode)->cache)
		return -ENOBUFS;

	netfs_readahead(ractl);
	return 0;
}

static atomic_t nfs_netfs_debug_id;
static int nfs_netfs_init_request(struct netfs_io_request *rreq, struct file *file)
{
	rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file));
	rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id);

	return 0;
}

static void nfs_netfs_free_request(struct netfs_io_request *rreq)
{
	put_nfs_open_context(rreq->netfs_priv);
}

static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq)
{
	struct nfs_netfs_io_data *netfs;

	netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT);
	if (!netfs)
		return NULL;
	netfs->sreq = sreq;
	refcount_set(&netfs->refcount, 1);
	return netfs;
}

static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq)
{
	size_t	rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize;

	sreq->len = min(sreq->len, rsize);
	return true;
}

static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq)
{
	struct nfs_netfs_io_data	*netfs;
	struct nfs_pageio_descriptor	pgio;
	struct inode *inode = sreq->rreq->inode;
	struct nfs_open_context *ctx = sreq->rreq->netfs_priv;
	struct page *page;
	unsigned long idx;
	int err;
	pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT;
	pgoff_t last = ((sreq->start + sreq->len -
			 sreq->transferred - 1) >> PAGE_SHIFT);

	nfs_pageio_init_read(&pgio, inode, false,
			     &nfs_async_read_completion_ops);

	netfs = nfs_netfs_alloc(sreq);
	if (!netfs)
		return netfs_subreq_terminated(sreq, -ENOMEM, false);

	pgio.pg_netfs = netfs; /* used in completion */

	xa_for_each_range(&sreq->rreq->mapping->i_pages, idx, page, start, last) {
		/* nfs_read_add_folio() may schedule() due to pNFS layout and other RPCs  */
		err = nfs_read_add_folio(&pgio, ctx, page_folio(page));
		if (err < 0) {
			netfs->error = err;
			goto out;
		}
	}
out:
	nfs_pageio_complete_read(&pgio);
	nfs_netfs_put(netfs);
}

void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr)
{
	struct nfs_netfs_io_data        *netfs = hdr->netfs;

	if (!netfs)
		return;

	nfs_netfs_get(netfs);
}

int nfs_netfs_folio_unlock(struct folio *folio)
{
	struct inode *inode = folio_file_mapping(folio)->host;

	/*
	 * If fscache is enabled, netfs will unlock pages.
	 */
	if (netfs_inode(inode)->cache)
		return 0;

	return 1;
}

void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
{
	struct nfs_netfs_io_data        *netfs = hdr->netfs;
	struct netfs_io_subrequest      *sreq;

	if (!netfs)
		return;

	sreq = netfs->sreq;
	if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
		__set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags);

	if (hdr->error)
		netfs->error = hdr->error;
	else
		atomic64_add(hdr->res.count, &netfs->transferred);

	nfs_netfs_put(netfs);
	hdr->netfs = NULL;
}

const struct netfs_request_ops nfs_netfs_ops = {
	.init_request		= nfs_netfs_init_request,
	.free_request		= nfs_netfs_free_request,
	.issue_read		= nfs_netfs_issue_read,
	.clamp_length		= nfs_netfs_clamp_length
};
Commit	Line	Data
b4d0d230	1	// SPDX-License-Identifier: GPL-2.0-or-later
14727281 DH	2	/* NFS filesystem cache interface
	3	*
	4	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells ([email protected])
14727281 DH	6	*/
	7
	8	#include <linux/init.h>
	9	#include <linux/kernel.h>
	10	#include <linux/sched.h>
	11	#include <linux/mm.h>
	12	#include <linux/nfs_fs.h>
	13	#include <linux/nfs_fs_sb.h>
	14	#include <linux/in6.h>
	15	#include <linux/seq_file.h>
5a0e3ad6	16	#include <linux/slab.h>
402cb8dd	17	#include <linux/iversion.h>
000dbe0b DW	18	#include <linux/xarray.h>
	19	#include <linux/fscache.h>
	20	#include <linux/netfs.h>
14727281 DH	21
14727281 DH	22	#include "internal.h"
545db45f	23	#include "iostat.h"
14727281	24	#include "fscache.h"
e3f0a7fe	25	#include "nfstrace.h"
14727281	26
a6b5a28e	27	#define NFS_MAX_KEY_LEN 1000
08734048	28
a6b5a28e DW	29	static bool nfs_append_int(char key, int _len, unsigned long long x)
	30	{
	31	if (*_len > NFS_MAX_KEY_LEN)
	32	return false;
	33	if (x == 0)
	34	key[(*_len)++] = ',';
	35	else
	36	_len += sprintf(key + _len, ",%llx", x);
	37	return true;
	38	}
402cb8dd	39
14727281 DH	40	/*
	41	* Get the per-client index cookie for an NFS client if the appropriate mount
	42	* flag was set
	43	* - We always try and get an index cookie for the client, but get filehandle
	44	* cookies on a per-superblock basis, depending on the mount flags
	45	*/
a6b5a28e DW	46	static bool nfs_fscache_get_client_key(struct nfs_client *clp,
a6b5a28e DW	47	char key, int _len)
14727281	48	{
402cb8dd DH	49	const struct sockaddr_in6 sin6 = (struct sockaddr_in6 ) &clp->cl_addr;
402cb8dd DH	50	const struct sockaddr_in sin = (struct sockaddr_in ) &clp->cl_addr;
402cb8dd	51
a6b5a28e DW	52	_len += snprintf(key + _len, NFS_MAX_KEY_LEN - *_len,
	53	",%u.%u,%x",
	54	clp->rpc_ops->version,
	55	clp->cl_minorversion,
	56	clp->cl_addr.ss_family);
402cb8dd DH	57
	58	switch (clp->cl_addr.ss_family) {
	59	case AF_INET:
a6b5a28e DW	60	if (!nfs_append_int(key, _len, sin->sin_port) \|\|
	61	!nfs_append_int(key, _len, sin->sin_addr.s_addr))
	62	return false;
	63	return true;
402cb8dd DH	64
402cb8dd DH	65	case AF_INET6:
a6b5a28e DW	66	if (!nfs_append_int(key, _len, sin6->sin6_port) \|\|
	67	!nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[0]) \|\|
	68	!nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[1]) \|\|
	69	!nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[2]) \|\|
	70	!nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[3]))
	71	return false;
	72	return true;
402cb8dd DH	73
	74	default:
	75	printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
	76	clp->cl_addr.ss_family);
a6b5a28e	77	return false;
402cb8dd	78	}
14727281	79	}
08734048 DH	80
08734048 DH	81	/*
a6b5a28e	82	* Get the cache cookie for an NFS superblock.
2df54806 DH	83	*
	84	* The default uniquifier is just an empty string, but it may be overridden
	85	* either by the 'fsc=xxx' option to mount, or by inheriting it from the parent
	86	* superblock across an automount point of some nature.
08734048	87	*/
a6b5a28e	88	int nfs_fscache_get_super_cookie(struct super_block sb, const char uniq, int ulen)
08734048	89	{
a6b5a28e	90	struct fscache_volume *vcookie;
08734048	91	struct nfs_server *nfss = NFS_SB(sb);
a6b5a28e DW	92	unsigned int len = 3;
a6b5a28e DW	93	char *key;
2df54806	94
a6b5a28e DW	95	if (uniq) {
	96	nfss->fscache_uniq = kmemdup_nul(uniq, ulen, GFP_KERNEL);
	97	if (!nfss->fscache_uniq)
	98	return -ENOMEM;
2df54806 DH	99	}
2df54806 DH	100
a6b5a28e	101	key = kmalloc(NFS_MAX_KEY_LEN + 24, GFP_KERNEL);
08734048	102	if (!key)
a6b5a28e DW	103	return -ENOMEM;
	104
	105	memcpy(key, "nfs", 3);
	106	if (!nfs_fscache_get_client_key(nfss->nfs_client, key, &len) \|\|
	107	!nfs_append_int(key, &len, nfss->fsid.major) \|\|
	108	!nfs_append_int(key, &len, nfss->fsid.minor) \|\|
	109	!nfs_append_int(key, &len, sb->s_flags & NFS_SB_MASK) \|\|
	110	!nfs_append_int(key, &len, nfss->flags) \|\|
	111	!nfs_append_int(key, &len, nfss->rsize) \|\|
	112	!nfs_append_int(key, &len, nfss->wsize) \|\|
	113	!nfs_append_int(key, &len, nfss->acregmin) \|\|
	114	!nfs_append_int(key, &len, nfss->acregmax) \|\|
	115	!nfs_append_int(key, &len, nfss->acdirmin) \|\|
	116	!nfs_append_int(key, &len, nfss->acdirmax) \|\|
	117	!nfs_append_int(key, &len, nfss->client->cl_auth->au_flavor))
	118	goto out;
	119
	120	if (ulen > 0) {
	121	if (ulen > NFS_MAX_KEY_LEN - len)
	122	goto out;
	123	key[len++] = ',';
	124	memcpy(key + len, uniq, ulen);
	125	len += ulen;
08734048	126	}
a6b5a28e	127	key[len] = 0;
08734048 DH	128
08734048 DH	129	/* create a cache index for looking up filehandles */
a6b5a28e DW	130	vcookie = fscache_acquire_volume(key,
	131	NULL, /* preferred_cache */
	132	NULL, 0 /* coherency_data */);
a6b5a28e DW	133	if (IS_ERR(vcookie)) {
	134	if (vcookie != ERR_PTR(-EBUSY)) {
	135	kfree(key);
	136	return PTR_ERR(vcookie);
	137	}
	138	pr_err("NFS: Cache volume key already in use (%s)\n", key);
	139	vcookie = NULL;
	140	}
	141	nfss->fscache = vcookie;
08734048	142
a6b5a28e	143	out:
08734048	144	kfree(key);
a6b5a28e	145	return 0;
08734048 DH	146	}
	147
	148	/*
	149	* release a per-superblock cookie
	150	*/
	151	void nfs_fscache_release_super_cookie(struct super_block *sb)
	152	{
	153	struct nfs_server *nfss = NFS_SB(sb);
	154
a6b5a28e	155	fscache_relinquish_volume(nfss->fscache, NULL, false);
08734048	156	nfss->fscache = NULL;
a6b5a28e	157	kfree(nfss->fscache_uniq);
50eaa652 DW	158	}
50eaa652 DW	159
ef79c097 DH	160	/*
	161	* Initialise the per-inode cache cookie pointer for an NFS inode.
	162	*/
f1fe29b4	163	void nfs_fscache_init_inode(struct inode *inode)
ef79c097	164	{
402cb8dd	165	struct nfs_fscache_inode_auxdata auxdata;
dea1bb35	166	struct nfs_server *nfss = NFS_SERVER(inode);
ef79c097 DH	167	struct nfs_inode *nfsi = NFS_I(inode);
ef79c097 DH	168
88a4d7bd	169	netfs_inode(inode)->cache = NULL;
dea1bb35	170	if (!(nfss->fscache && S_ISREG(inode->i_mode)))
ef79c097	171	return;
402cb8dd	172
45f3a70b	173	nfs_fscache_update_auxdata(&auxdata, inode);
402cb8dd	174
88a4d7bd DW	175	netfs_inode(inode)->cache = fscache_acquire_cookie(
88a4d7bd DW	176	nfss->fscache,
a6b5a28e DW	177	0,
	178	nfsi->fh.data, /* index_key */
	179	nfsi->fh.size,
	180	&auxdata, /* aux_data */
	181	sizeof(auxdata),
45f3a70b	182	i_size_read(inode));
b4fa966f DH	183
	184	if (netfs_inode(inode)->cache)
	185	mapping_set_release_always(inode->i_mapping);
ef79c097 DH	186	}
	187
	188	/*
	189	* Release a per-inode cookie.
	190	*/
f1fe29b4	191	void nfs_fscache_clear_inode(struct inode *inode)
ef79c097	192	{
88a4d7bd DW	193	fscache_relinquish_cookie(netfs_i_cookie(netfs_inode(inode)), false);
88a4d7bd DW	194	netfs_inode(inode)->cache = NULL;
ef79c097 DH	195	}
ef79c097 DH	196
ef79c097	197	/*
f1fe29b4 DH	198	* Enable or disable caching for a file that is being opened as appropriate.
	199	* The cookie is allocated when the inode is initialised, but is not enabled at
	200	* that time. Enablement is deferred to file-open time to avoid stat() and
	201	* access() thrashing the cache.
	202	*
	203	* For now, with NFS, only regular files that are open read-only will be able
	204	* to use the cache.
	205	*
	206	* We enable the cache for an inode if we open it read-only and it isn't
	207	* currently open for writing. We disable the cache if the inode is open
	208	* write-only.
	209	*
	210	* The caller uses the file struct to pin i_writecount on the inode before
	211	* calling us when a file is opened for writing, so we can make use of that.
	212	*
	213	* Note that this may be invoked multiple times in parallel by parallel
	214	* nfs_open() functions.
ef79c097	215	*/
f1fe29b4	216	void nfs_fscache_open_file(struct inode inode, struct file filp)
ef79c097	217	{
402cb8dd	218	struct nfs_fscache_inode_auxdata auxdata;
88a4d7bd	219	struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
a6b5a28e	220	bool open_for_write = inode_is_open_for_write(inode);
ef79c097	221
f1fe29b4 DH	222	if (!fscache_cookie_valid(cookie))
f1fe29b4 DH	223	return;
ef79c097	224
a6b5a28e DW	225	fscache_use_cookie(cookie, open_for_write);
a6b5a28e DW	226	if (open_for_write) {
45f3a70b	227	nfs_fscache_update_auxdata(&auxdata, inode);
a6b5a28e DW	228	fscache_invalidate(cookie, &auxdata, i_size_read(inode),
a6b5a28e DW	229	FSCACHE_INVAL_DIO_WRITE);
ef79c097	230	}
ef79c097	231	}
f1fe29b4	232	EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
545db45f	233
a6b5a28e	234	void nfs_fscache_release_file(struct inode inode, struct file filp)
545db45f	235	{
a6b5a28e	236	struct nfs_fscache_inode_auxdata auxdata;
88a4d7bd	237	struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
9c4a5c75	238	loff_t i_size = i_size_read(inode);
545db45f	239
9c4a5c75 DW	240	nfs_fscache_update_auxdata(&auxdata, inode);
9c4a5c75 DW	241	fscache_unuse_cookie(cookie, &auxdata, &i_size);
9a9fc1c0 DH	242	}
9a9fc1c0 DH	243
000dbe0b	244	int nfs_netfs_read_folio(struct file file, struct folio folio)
16f2f4e6	245	{
000dbe0b DW	246	if (!netfs_inode(folio_inode(folio))->cache)
	247	return -ENOBUFS;
	248
	249	return netfs_read_folio(file, folio);
16f2f4e6 DH	250	}
16f2f4e6 DH	251
000dbe0b	252	int nfs_netfs_readahead(struct readahead_control *ractl)
16f2f4e6	253	{
000dbe0b DW	254	struct inode *inode = ractl->mapping->host;
	255
	256	if (!netfs_inode(inode)->cache)
	257	return -ENOBUFS;
	258
	259	netfs_readahead(ractl);
	260	return 0;
16f2f4e6 DH	261	}
16f2f4e6 DH	262
c5733ae6	263	static atomic_t nfs_netfs_debug_id;
000dbe0b	264	static int nfs_netfs_init_request(struct netfs_io_request rreq, struct file file)
9a9fc1c0	265	{
000dbe0b DW	266	rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file));
000dbe0b DW	267	rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id);
16f2f4e6	268
000dbe0b DW	269	return 0;
000dbe0b DW	270	}
ba512c1b	271
000dbe0b DW	272	static void nfs_netfs_free_request(struct netfs_io_request *rreq)
	273	{
	274	put_nfs_open_context(rreq->netfs_priv);
	275	}
9a9fc1c0	276
000dbe0b	277	static struct nfs_netfs_io_data nfs_netfs_alloc(struct netfs_io_subrequest sreq)
7f8e05f6	278	{
000dbe0b DW	279	struct nfs_netfs_io_data *netfs;
	280
	281	netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT);
	282	if (!netfs)
	283	return NULL;
	284	netfs->sreq = sreq;
	285	refcount_set(&netfs->refcount, 1);
	286	return netfs;
	287	}
16f2f4e6	288
000dbe0b DW	289	static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq)
	290	{
	291	size_t rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize;
7f8e05f6	292
000dbe0b DW	293	sreq->len = min(sreq->len, rsize);
	294	return true;
	295	}
16f2f4e6	296
000dbe0b DW	297	static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq)
	298	{
	299	struct nfs_netfs_io_data *netfs;
	300	struct nfs_pageio_descriptor pgio;
	301	struct inode *inode = sreq->rreq->inode;
	302	struct nfs_open_context *ctx = sreq->rreq->netfs_priv;
	303	struct page *page;
fd5860ab	304	unsigned long idx;
000dbe0b DW	305	int err;
	306	pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT;
	307	pgoff_t last = ((sreq->start + sreq->len -
	308	sreq->transferred - 1) >> PAGE_SHIFT);
000dbe0b DW	309
	310	nfs_pageio_init_read(&pgio, inode, false,
	311	&nfs_async_read_completion_ops);
	312
	313	netfs = nfs_netfs_alloc(sreq);
	314	if (!netfs)
	315	return netfs_subreq_terminated(sreq, -ENOMEM, false);
	316
	317	pgio.pg_netfs = netfs; /* used in completion */
	318
fd5860ab	319	xa_for_each_range(&sreq->rreq->mapping->i_pages, idx, page, start, last) {
000dbe0b	320	/* nfs_read_add_folio() may schedule() due to pNFS layout and other RPCs */
000dbe0b DW	321	err = nfs_read_add_folio(&pgio, ctx, page_folio(page));
	322	if (err < 0) {
	323	netfs->error = err;
	324	goto out;
	325	}
16f2f4e6	326	}
000dbe0b DW	327	out:
	328	nfs_pageio_complete_read(&pgio);
	329	nfs_netfs_put(netfs);
7f8e05f6	330	}
000dbe0b DW	331
	332	void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr)
	333	{
	334	struct nfs_netfs_io_data *netfs = hdr->netfs;
	335
	336	if (!netfs)
	337	return;
	338
	339	nfs_netfs_get(netfs);
	340	}
	341
	342	int nfs_netfs_folio_unlock(struct folio *folio)
	343	{
	344	struct inode *inode = folio_file_mapping(folio)->host;
	345
	346	/*
	347	* If fscache is enabled, netfs will unlock pages.
	348	*/
	349	if (netfs_inode(inode)->cache)
	350	return 0;
	351
	352	return 1;
	353	}
	354
	355	void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
	356	{
	357	struct nfs_netfs_io_data *netfs = hdr->netfs;
	358	struct netfs_io_subrequest *sreq;
	359
	360	if (!netfs)
	361	return;
	362
	363	sreq = netfs->sreq;
	364	if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
	365	__set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags);
	366
	367	if (hdr->error)
	368	netfs->error = hdr->error;
	369	else
	370	atomic64_add(hdr->res.count, &netfs->transferred);
	371
	372	nfs_netfs_put(netfs);
	373	hdr->netfs = NULL;
	374	}
	375
	376	const struct netfs_request_ops nfs_netfs_ops = {
	377	.init_request = nfs_netfs_init_request,
	378	.free_request = nfs_netfs_free_request,
000dbe0b DW	379	.issue_read = nfs_netfs_issue_read,
	380	.clamp_length = nfs_netfs_clamp_length
	381	};