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Release 4.11 fs/nfs/cache_lib.c

Directory: fs/nfs
/*
 * linux/fs/nfs/cache_lib.c
 *
 * Helper routines for the NFS client caches
 *
 * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
 */
#include <linux/kmod.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; }

Contributors

PersonTokensPropCommitsCommitProp
Trond Myklebust112100.00%1100.00%
Total112100.00%1100.00%

/* * Deferred request handling */
void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq) { if (atomic_dec_and_test(&dreq->count)) kfree(dreq); }

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PersonTokensPropCommitsCommitProp
Trond Myklebust25100.00%1100.00%
Total25100.00%1100.00%


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); }

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PersonTokensPropCommitsCommitProp
Trond Myklebust4397.73%150.00%
Daniel Wagner12.27%150.00%
Total44100.00%2100.00%


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; atomic_inc(&dreq->count); return &dreq->deferred_req; }

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PersonTokensPropCommitsCommitProp
Trond Myklebust52100.00%1100.00%
Total52100.00%1100.00%


struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void) { struct nfs_cache_defer_req *dreq; dreq = kzalloc(sizeof(*dreq), GFP_KERNEL); if (dreq) { init_completion(&dreq->completion); atomic_set(&dreq->count, 1); dreq->req.defer = nfs_dns_cache_defer; } return dreq; }

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PersonTokensPropCommitsCommitProp
Trond Myklebust62100.00%1100.00%
Total62100.00%1100.00%


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; }

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PersonTokensPropCommitsCommitProp
Trond Myklebust33100.00%1100.00%
Total33100.00%1100.00%


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; }

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PersonTokensPropCommitsCommitProp
Stanislav Kinsbursky55100.00%1100.00%
Total55100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Stanislav Kinsbursky3753.62%360.00%
Trond Myklebust3144.93%120.00%
Al Viro11.45%120.00%
Total69100.00%5100.00%


void nfs_cache_unregister_sb(struct super_block *sb, struct cache_detail *cd) { sunrpc_cache_unregister_pipefs(cd); }

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PersonTokensPropCommitsCommitProp
Trond Myklebust1365.00%150.00%
Stanislav Kinsbursky735.00%150.00%
Total20100.00%2100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Stanislav Kinsbursky50100.00%3100.00%
Total50100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Trond Myklebust46174.60%111.11%
Stanislav Kinsbursky15224.60%555.56%
Tejun Heo30.49%111.11%
Al Viro10.16%111.11%
Daniel Wagner10.16%111.11%
Total618100.00%9100.00%
Directory: fs/nfs
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