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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159// SPDX-License-Identifier: GPL-2.0/* * linux/fs/nfs/cache_lib.c * * Helper routines for the NFS client caches * * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com> */#include <linux/umh.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/mount.h>#include <linux/namei.h>#include <linux/slab.h>#include <linux/sunrpc/cache.h>#include <linux/sunrpc/rpc_pipe_fs.h>#include <net/net_namespace.h>
#include "cache_lib.h"
#define NFS_CACHE_UPCALL_PATHLEN 256#define NFS_CACHE_UPCALL_TIMEOUT 15
static char nfs_cache_getent_prog[NFS_CACHE_UPCALL_PATHLEN] = "/sbin/nfs_cache_getent";static unsigned long nfs_cache_getent_timeout = NFS_CACHE_UPCALL_TIMEOUT;
module_param_string(cache_getent, nfs_cache_getent_prog, sizeof(nfs_cache_getent_prog), 0600);MODULE_PARM_DESC(cache_getent, "Path to the client cache upcall program");module_param_named(cache_getent_timeout, nfs_cache_getent_timeout, ulong, 0600);MODULE_PARM_DESC(cache_getent_timeout, "Timeout (in seconds) after which " "the cache upcall is assumed to have failed");
int nfs_cache_upcall(struct cache_detail *cd, char *entry_name){ static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL }; char *argv[] = { nfs_cache_getent_prog, cd->name, entry_name, NULL }; int ret = -EACCES;
if (nfs_cache_getent_prog[0] == '\0') goto out; ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); /* * Disable the upcall mechanism if we're getting an ENOENT or * EACCES error. The admin can re-enable it on the fly by using * sysfs to set the 'cache_getent' parameter once the problem * has been fixed. */ if (ret == -ENOENT || ret == -EACCES) nfs_cache_getent_prog[0] = '\0';out: return ret > 0 ? 0 : ret;}
/* * Deferred request handling */void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq){ if (refcount_dec_and_test(&dreq->count)) kfree(dreq);}
static void nfs_dns_cache_revisit(struct cache_deferred_req *d, int toomany){ struct nfs_cache_defer_req *dreq;
dreq = container_of(d, struct nfs_cache_defer_req, deferred_req);
complete(&dreq->completion); nfs_cache_defer_req_put(dreq);}
static struct cache_deferred_req *nfs_dns_cache_defer(struct cache_req *req){ struct nfs_cache_defer_req *dreq;
dreq = container_of(req, struct nfs_cache_defer_req, req); dreq->deferred_req.revisit = nfs_dns_cache_revisit; refcount_inc(&dreq->count);
return &dreq->deferred_req;}
struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void){ struct nfs_cache_defer_req *dreq;
dreq = kzalloc_obj(*dreq); if (dreq) { init_completion(&dreq->completion); refcount_set(&dreq->count, 1); dreq->req.defer = nfs_dns_cache_defer; } return dreq;}
int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq){ if (wait_for_completion_timeout(&dreq->completion, nfs_cache_getent_timeout * HZ) == 0) return -ETIMEDOUT; return 0;}
int nfs_cache_register_sb(struct super_block *sb, struct cache_detail *cd){ int ret; struct dentry *dir;
dir = rpc_d_lookup_sb(sb, "cache"); ret = sunrpc_cache_register_pipefs(dir, cd->name, 0600, cd); dput(dir); return ret;}
int nfs_cache_register_net(struct net *net, struct cache_detail *cd){ struct super_block *pipefs_sb; int ret = 0;
sunrpc_init_cache_detail(cd); pipefs_sb = rpc_get_sb_net(net); if (pipefs_sb) { ret = nfs_cache_register_sb(pipefs_sb, cd); rpc_put_sb_net(net); if (ret) sunrpc_destroy_cache_detail(cd); } return ret;}
void nfs_cache_unregister_sb(struct super_block *sb, struct cache_detail *cd){ sunrpc_cache_unregister_pipefs(cd);}
void nfs_cache_unregister_net(struct net *net, struct cache_detail *cd){ struct super_block *pipefs_sb;
pipefs_sb = rpc_get_sb_net(net); if (pipefs_sb) { nfs_cache_unregister_sb(pipefs_sb, cd); rpc_put_sb_net(net); } sunrpc_destroy_cache_detail(cd);}