Orange Pi5 kernel

// 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 (dhowells@redhat.com)
 */
 
#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 "internal.h"
#include "iostat.h"
#include "fscache.h"
 
#define NFSDBG_FACILITY		NFSDBG_FSCACHE
 
static struct rb_root nfs_fscache_keys = RB_ROOT;
static DEFINE_SPINLOCK(nfs_fscache_keys_lock);
 
/*
 * Layout of the key for an NFS server cache object.
 */
struct nfs_server_key {
<------>struct {
<------><------>uint16_t	nfsversion;		/* NFS protocol version */
<------><------>uint32_t	minorversion;		/* NFSv4 minor version */
<------><------>uint16_t	family;			/* address family */
<------><------>__be16		port;			/* IP port */
<------>} hdr;
<------>union {
<------><------>struct in_addr	ipv4_addr;	/* IPv4 address */
<------><------>struct in6_addr ipv6_addr;	/* IPv6 address */
<------>};
} __packed;
 
/*
 * 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
 */
void nfs_fscache_get_client_cookie(struct nfs_client *clp)
{
<------>const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr;
<------>const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr;
<------>struct nfs_server_key key;
<------>uint16_t len = sizeof(key.hdr);
 
<------>memset(&key, 0, sizeof(key));
<------>key.hdr.nfsversion = clp->rpc_ops->version;
<------>key.hdr.minorversion = clp->cl_minorversion;
<------>key.hdr.family = clp->cl_addr.ss_family;
 
<------>switch (clp->cl_addr.ss_family) {
<------>case AF_INET:
<------><------>key.hdr.port = sin->sin_port;
<------><------>key.ipv4_addr = sin->sin_addr;
<------><------>len += sizeof(key.ipv4_addr);
<------><------>break;
 
<------>case AF_INET6:
<------><------>key.hdr.port = sin6->sin6_port;
<------><------>key.ipv6_addr = sin6->sin6_addr;
<------><------>len += sizeof(key.ipv6_addr);
<------><------>break;
 
<------>default:
<------><------>printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
<------><------>       clp->cl_addr.ss_family);
<------><------>clp->fscache = NULL;
<------><------>return;
<------>}
 
<------>/* create a cache index for looking up filehandles */
<------>clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index,
<------><------><------><------><------>      &nfs_fscache_server_index_def,
<------><------><------><------><------>      &key, len,
<------><------><------><------><------>      NULL, 0,
<------><------><------><------><------>      clp, 0, true);
<------>dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n",
<------><------> clp, clp->fscache);
}
 
/*
 * Dispose of a per-client cookie
 */
void nfs_fscache_release_client_cookie(struct nfs_client *clp)
{
<------>dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n",
<------><------> clp, clp->fscache);
 
<------>fscache_relinquish_cookie(clp->fscache, NULL, false);
<------>clp->fscache = NULL;
}
 
/*
 * Get the cache cookie for an NFS superblock.  We have to handle
 * uniquification here because the cache doesn't do it for us.
 *
 * 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.
 */
void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen)
{
<------>struct nfs_fscache_key *key, *xkey;
<------>struct nfs_server *nfss = NFS_SB(sb);
<------>struct rb_node **p, *parent;
<------>int diff;
 
<------>nfss->fscache_key = NULL;
<------>nfss->fscache = NULL;
<------>if (!uniq) {
<------><------>uniq = "";
<------><------>ulen = 1;
<------>}
 
<------>key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL);
<------>if (!key)
<------><------>return;
 
<------>key->nfs_client = nfss->nfs_client;
<------>key->key.super.s_flags = sb->s_flags & NFS_SB_MASK;
<------>key->key.nfs_server.flags = nfss->flags;
<------>key->key.nfs_server.rsize = nfss->rsize;
<------>key->key.nfs_server.wsize = nfss->wsize;
<------>key->key.nfs_server.acregmin = nfss->acregmin;
<------>key->key.nfs_server.acregmax = nfss->acregmax;
<------>key->key.nfs_server.acdirmin = nfss->acdirmin;
<------>key->key.nfs_server.acdirmax = nfss->acdirmax;
<------>key->key.nfs_server.fsid = nfss->fsid;
<------>key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor;
 
<------>key->key.uniq_len = ulen;
<------>memcpy(key->key.uniquifier, uniq, ulen);
 
<------>spin_lock(&nfs_fscache_keys_lock);
<------>p = &nfs_fscache_keys.rb_node;
<------>parent = NULL;
<------>while (*p) {
<------><------>parent = *p;
<------><------>xkey = rb_entry(parent, struct nfs_fscache_key, node);
 
<------><------>if (key->nfs_client < xkey->nfs_client)
<------><------><------>goto go_left;
<------><------>if (key->nfs_client > xkey->nfs_client)
<------><------><------>goto go_right;
 
<------><------>diff = memcmp(&key->key, &xkey->key, sizeof(key->key));
<------><------>if (diff < 0)
<------><------><------>goto go_left;
<------><------>if (diff > 0)
<------><------><------>goto go_right;
 
<------><------>if (key->key.uniq_len == 0)
<------><------><------>goto non_unique;
<------><------>diff = memcmp(key->key.uniquifier,
<------><------><------>      xkey->key.uniquifier,
<------><------><------>      key->key.uniq_len);
<------><------>if (diff < 0)
<------><------><------>goto go_left;
<------><------>if (diff > 0)
<------><------><------>goto go_right;
<------><------>goto non_unique;
 
<------>go_left:
<------><------>p = &(*p)->rb_left;
<------><------>continue;
<------>go_right:
<------><------>p = &(*p)->rb_right;
<------>}
 
<------>rb_link_node(&key->node, parent, p);
<------>rb_insert_color(&key->node, &nfs_fscache_keys);
<------>spin_unlock(&nfs_fscache_keys_lock);
<------>nfss->fscache_key = key;
 
<------>/* create a cache index for looking up filehandles */
<------>nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache,
<------><------><------><------><------>       &nfs_fscache_super_index_def,
<------><------><------><------><------>       &key->key,
<------><------><------><------><------>       sizeof(key->key) + ulen,
<------><------><------><------><------>       NULL, 0,
<------><------><------><------><------>       nfss, 0, true);
<------>dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n",
<------><------> nfss, nfss->fscache);
<------>return;
 
non_unique:
<------>spin_unlock(&nfs_fscache_keys_lock);
<------>kfree(key);
<------>nfss->fscache_key = NULL;
<------>nfss->fscache = NULL;
<------>printk(KERN_WARNING "NFS:"
<------>       " Cache request denied due to non-unique superblock keys\n");
}
 
/*
 * release a per-superblock cookie
 */
void nfs_fscache_release_super_cookie(struct super_block *sb)
{
<------>struct nfs_server *nfss = NFS_SB(sb);
 
<------>dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n",
<------><------> nfss, nfss->fscache);
 
<------>fscache_relinquish_cookie(nfss->fscache, NULL, false);
<------>nfss->fscache = NULL;
 
<------>if (nfss->fscache_key) {
<------><------>spin_lock(&nfs_fscache_keys_lock);
<------><------>rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys);
<------><------>spin_unlock(&nfs_fscache_keys_lock);
<------><------>kfree(nfss->fscache_key);
<------><------>nfss->fscache_key = NULL;
<------>}
}
 
static void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
<------><------><------><------>  struct nfs_inode *nfsi)
{
<------>memset(auxdata, 0, sizeof(*auxdata));
<------>auxdata->mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
<------>auxdata->mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
<------>auxdata->ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
<------>auxdata->ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
 
<------>if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
<------><------>auxdata->change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
}
 
/*
 * 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);
 
<------>nfsi->fscache = NULL;
<------>if (!(nfss->fscache && S_ISREG(inode->i_mode)))
<------><------>return;
 
<------>nfs_fscache_update_auxdata(&auxdata, nfsi);
 
<------>nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
<------><------><------><------><------>       &nfs_fscache_inode_object_def,
<------><------><------><------><------>       nfsi->fh.data, nfsi->fh.size,
<------><------><------><------><------>       &auxdata, sizeof(auxdata),
<------><------><------><------><------>       nfsi, nfsi->vfs_inode.i_size, false);
}
 
/*
 * Release a per-inode cookie.
 */
void nfs_fscache_clear_inode(struct inode *inode)
{
<------>struct nfs_fscache_inode_auxdata auxdata;
<------>struct nfs_inode *nfsi = NFS_I(inode);
<------>struct fscache_cookie *cookie = nfs_i_fscache(inode);
 
<------>dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie);
 
<------>nfs_fscache_update_auxdata(&auxdata, nfsi);
<------>fscache_relinquish_cookie(cookie, &auxdata, false);
<------>nfsi->fscache = NULL;
}
 
static bool nfs_fscache_can_enable(void *data)
{
<------>struct inode *inode = data;
 
<------>return !inode_is_open_for_write(inode);
}
 
/*
 * 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 nfs_inode *nfsi = NFS_I(inode);
<------>struct fscache_cookie *cookie = nfs_i_fscache(inode);
 
<------>if (!fscache_cookie_valid(cookie))
<------><------>return;
 
<------>nfs_fscache_update_auxdata(&auxdata, nfsi);
 
<------>if (inode_is_open_for_write(inode)) {
<------><------>dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);
<------><------>clear_bit(NFS_INO_FSCACHE, &nfsi->flags);
<------><------>fscache_disable_cookie(cookie, &auxdata, true);
<------><------>fscache_uncache_all_inode_pages(cookie, inode);
<------>} else {
<------><------>dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi);
<------><------>fscache_enable_cookie(cookie, &auxdata, nfsi->vfs_inode.i_size,
<------><------><------><------>      nfs_fscache_can_enable, inode);
<------><------>if (fscache_cookie_enabled(cookie))
<------><------><------>set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
<------>}
}
EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
 
/*
 * Release the caching state associated with a page, if the page isn't busy
 * interacting with the cache.
 * - Returns true (can release page) or false (page busy).
 */
int nfs_fscache_release_page(struct page *page, gfp_t gfp)
{
<------>if (PageFsCache(page)) {
<------><------>struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host);
 
<------><------>BUG_ON(!cookie);
<------><------>dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n",
<------><------><------> cookie, page, NFS_I(page->mapping->host));
 
<------><------>if (!fscache_maybe_release_page(cookie, page, gfp))
<------><------><------>return 0;
 
<------><------>nfs_inc_fscache_stats(page->mapping->host,
<------><------><------><------>      NFSIOS_FSCACHE_PAGES_UNCACHED);
<------>}
 
<------>return 1;
}
 
/*
 * Release the caching state associated with a page if undergoing complete page
 * invalidation.
 */
void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
{
<------>struct fscache_cookie *cookie = nfs_i_fscache(inode);
 
<------>BUG_ON(!cookie);
 
<------>dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n",
<------><------> cookie, page, NFS_I(inode));
 
<------>fscache_wait_on_page_write(cookie, page);
 
<------>BUG_ON(!PageLocked(page));
<------>fscache_uncache_page(cookie, page);
<------>nfs_inc_fscache_stats(page->mapping->host,
<------><------><------>      NFSIOS_FSCACHE_PAGES_UNCACHED);
}
 
/*
 * Handle completion of a page being read from the cache.
 * - Called in process (keventd) context.
 */
static void nfs_readpage_from_fscache_complete(struct page *page,
<------><------><------><------><------>       void *context,
<------><------><------><------><------>       int error)
{
<------>dfprintk(FSCACHE,
<------><------> "NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n",
<------><------> page, context, error);
 
<------>/* if the read completes with an error, we just unlock the page and let
<------> * the VM reissue the readpage */
<------>if (!error) {
<------><------>SetPageUptodate(page);
<------><------>unlock_page(page);
<------>} else {
<------><------>error = nfs_readpage_async(context, page->mapping->host, page);
<------><------>if (error)
<------><------><------>unlock_page(page);
<------>}
}
 
/*
 * Retrieve a page from fscache
 */
int __nfs_readpage_from_fscache(struct nfs_open_context *ctx,
<------><------><------><------>struct inode *inode, struct page *page)
{
<------>int ret;
 
<------>dfprintk(FSCACHE,
<------><------> "NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n",
<------><------> nfs_i_fscache(inode), page, page->index, page->flags, inode);
 
<------>ret = fscache_read_or_alloc_page(nfs_i_fscache(inode),
<------><------><------><------><------> page,
<------><------><------><------><------> nfs_readpage_from_fscache_complete,
<------><------><------><------><------> ctx,
<------><------><------><------><------> GFP_KERNEL);
 
<------>switch (ret) {
<------>case 0: /* read BIO submitted (page in fscache) */
<------><------>dfprintk(FSCACHE,
<------><------><------> "NFS:    readpage_from_fscache: BIO submitted\n");
<------><------>nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
<------><------>return ret;
 
<------>case -ENOBUFS: /* inode not in cache */
<------>case -ENODATA: /* page not in cache */
<------><------>nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
<------><------>dfprintk(FSCACHE,
<------><------><------> "NFS:    readpage_from_fscache %d\n", ret);
<------><------>return 1;
 
<------>default:
<------><------>dfprintk(FSCACHE, "NFS:    readpage_from_fscache %d\n", ret);
<------><------>nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
<------>}
<------>return ret;
}
 
/*
 * Retrieve a set of pages from fscache
 */
int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
<------><------><------><------> struct inode *inode,
<------><------><------><------> struct address_space *mapping,
<------><------><------><------> struct list_head *pages,
<------><------><------><------> unsigned *nr_pages)
{
<------>unsigned npages = *nr_pages;
<------>int ret;
 
<------>dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n",
<------><------> nfs_i_fscache(inode), npages, inode);
 
<------>ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
<------><------><------><------><------>  mapping, pages, nr_pages,
<------><------><------><------><------>  nfs_readpage_from_fscache_complete,
<------><------><------><------><------>  ctx,
<------><------><------><------><------>  mapping_gfp_mask(mapping));
<------>if (*nr_pages < npages)
<------><------>nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK,
<------><------><------><------>      npages);
<------>if (*nr_pages > 0)
<------><------>nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
<------><------><------><------>      *nr_pages);
 
<------>switch (ret) {
<------>case 0: /* read submitted to the cache for all pages */
<------><------>BUG_ON(!list_empty(pages));
<------><------>BUG_ON(*nr_pages != 0);
<------><------>dfprintk(FSCACHE,
<------><------><------> "NFS: nfs_getpages_from_fscache: submitted\n");
 
<------><------>return ret;
 
<------>case -ENOBUFS: /* some pages aren't cached and can't be */
<------>case -ENODATA: /* some pages aren't cached */
<------><------>dfprintk(FSCACHE,
<------><------><------> "NFS: nfs_getpages_from_fscache: no page: %d\n", ret);
<------><------>return 1;
 
<------>default:
<------><------>dfprintk(FSCACHE,
<------><------><------> "NFS: nfs_getpages_from_fscache: ret  %d\n", ret);
<------>}
 
<------>return ret;
}
 
/*
 * Store a newly fetched page in fscache
 * - PG_fscache must be set on the page
 */
void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
{
<------>int ret;
 
<------>dfprintk(FSCACHE,
<------><------> "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n",
<------><------> nfs_i_fscache(inode), page, page->index, page->flags, sync);
 
<------>ret = fscache_write_page(nfs_i_fscache(inode), page,
<------><------><------><------> inode->i_size, GFP_KERNEL);
<------>dfprintk(FSCACHE,
<------><------> "NFS:     readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n",
<------><------> page, page->index, page->flags, ret);
 
<------>if (ret != 0) {
<------><------>fscache_uncache_page(nfs_i_fscache(inode), page);
<------><------>nfs_inc_fscache_stats(inode,
<------><------><------><------>      NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
<------><------>nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
<------>} else {
<------><------>nfs_inc_fscache_stats(inode,
<------><------><------><------>      NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
<------>}
}