/*
* linux/fs/lockd/svcsubs.c
*
* Various support routines for the NLM server.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/nfsfh.h>
#include <linux/nfsd/export.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/share.h>
#include <linux/module.h>
#include <linux/mount.h>
#define NLMDBG_FACILITY NLMDBG_SVCSUBS
/*
* Global file hash table
*/
#define FILE_HASH_BITS 7
#define FILE_NRHASH (1<<FILE_HASH_BITS)
static struct hlist_head nlm_files[FILE_NRHASH];
static DEFINE_MUTEX(nlm_file_mutex);
#ifdef NFSD_DEBUG
static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
{
u32 *fhp = (u32*)f->data;
/* print the first 32 bytes of the fh */
dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n",
msg, fhp[0], fhp[1], fhp[2], fhp[3],
fhp[4], fhp[5], fhp[6], fhp[7]);
}
static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
{
struct inode *inode = file->f_file->f_path.dentry->d_inode;
dprintk("lockd: %s %s/%ld\n",
msg, inode->i_sb->s_id, inode->i_ino);
}
#else
static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
{
return;
}
static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
{
return;
}
#endif
static inline unsigned int file_hash(struct nfs_fh *f)
{
unsigned int tmp=0;
int i;
for (i=0; i<NFS2_FHSIZE;i++)
tmp += f->data[i];
return tmp & (FILE_NRHASH - 1);
}
/*
* Lookup file info. If it doesn't exist, create a file info struct
* and open a (VFS) file for the given inode.
*
* FIXME:
* Note that we open the file O_RDONLY even when creating write locks.
* This is not quite right, but for now, we assume the client performs
* the proper R/W checking.
*/
__be32
nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
struct nfs_fh *f)
{
struct hlist_node *pos;
struct nlm_file *file;
unsigned int hash;
__be32 nfserr;
nlm_debug_print_fh("nlm_lookup_file", f);
hash = file_hash(f);
/* Lock file table */
mutex_lock(&nlm_file_mutex);
hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
if (!nfs_compare_fh(&file->f_handle, f))
goto found;
nlm_debug_print_fh("creating file for", f);
nfserr = nlm_lck_denied_nolocks;
file = kzalloc(sizeof(*file), GFP_KERNEL);
if (!file)
goto out_unlock;
memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
mutex_init(&file->f_mutex);
INIT_HLIST_NODE(&file->f_list);
INIT_LIST_HEAD(&file->f_blocks);
/* Open the file. Note that this must not sleep for too long, else
* we would lock up lockd:-) So no NFS re-exports, folks.
*
* We have to make sure we have the right credential to open
* the file.
*/
if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) {
dprintk("lockd: open failed (error %d)\n", nfserr);
goto out_free;
}
hlist_add_head(&file->f_list, &nlm_files[hash]);
found:
dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
*result = file;
file->f_count++;
nfserr = 0;
out_unlock:
mutex_unlock(&nlm_file_mutex);
return nfserr;
out_free:
kfree(file);
goto out_unlock;
}
/*
* Delete a file after having released all locks, blocks and shares
*/
static inline void
nlm_delete_file(struct nlm_file *file)
{
nlm_debug_print_file("closing file", file);
if (!hlist_unhashed(&file->f_list)) {
hlist_del(&file->f_list);
nlmsvc_ops->fclose(file->f_file);
kfree(file);
} else {
printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
}
}
/*
* Loop over all locks on the given file and perform the specified
* action.
*/
static int
nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
nlm_host_match_fn_t match)
{
struct inode *inode = nlmsvc_file_inode(file);
struct file_lock *fl;
struct nlm_host *lockhost;
again:
file->f_locks = 0;
lock_flocks(); /* protects i_flock list */
for (fl = inode->i_flock; fl; fl = fl->fl_next) {
if (fl->fl_lmops != &nlmsvc_lock_operations)
continue;
/* update current lock count */
file->f_locks++;
lockhost = (struct nlm_host *) fl->fl_owner;
if (match(lockhost, host)) {
struct file_lock lock = *fl;
unlock_flocks();
lock.fl_type = F_UNLCK;
lock.fl_start = 0;
lock.fl_end = OFFSET_MAX;
if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
printk("lockd: unlock failure in %s:%d\n",
__FILE__, __LINE__);
return 1;
}
goto again;
}
}
unlock_flocks();
return 0;
}
static int
nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
{
return 1;
}
/*
* Inspect a single file
*/
static inline int
nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
{
nlmsvc_traverse_blocks(host, file, match);
nlmsvc_traverse_shares(host, file, match);
return nlm_traverse_locks(host, file, match);
}
/*
* Quick check whether there are still any locks, blocks or
* shares on a given file.
*/
static inline int
nlm_file_inuse(struct nlm_file *file)
{
struct inode *inode = nlmsvc_file_inode(file);
struct file_lock *fl;
if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
return 1;
lock_flocks();
for (fl = inode->i_flock; fl; fl = fl->fl_next) {
if (fl->fl_lmops == &nlmsvc_lock_operations) {
unlock_flocks();
return 1;
}
}
unlock_flocks();
file->f_locks = 0;
return 0;
}
/*
* Loop over all files in the file table.
*/
static int
nlm_traverse_files(void *data, nlm_host_match_fn_t match,
int (*is_failover_file)(void *data, struct nlm_file *file))
{
struct hlist_node *pos, *next;
struct nlm_file *file;
int i, ret = 0;
mutex_lock(&nlm_file_mutex);
for (i = 0; i < FILE_NRHASH; i++) {
hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
if (is_failover_file && !is_failover_file(data, file))
continue;
file->f_count++;
mutex_unlock(&nlm_file_mutex);
/* Traverse locks, blocks and shares of this file
* and update file->f_locks count */
if (nlm_inspect_file(data, file, match))
ret = 1;
mutex_lock(&nlm_file_mutex);
file->f_count--;
/* No more references to this file. Let go of it. */
if (list_empty(&file->f_blocks) && !file->f_locks
&& !file->f_shares && !file->f_count) {
hlist_del(&file->f_list);
nlmsvc_ops->fclose(file->f_file);
kfree(file);
}
}
}
mutex_unlock(&nlm_file_mutex);
return ret;
}
/*
* Release file. If there are no more remote locks on this file,
* close it and free the handle.
*
* Note that we can't do proper reference counting without major
* contortions because the code in fs/locks.c creates, deletes and
* splits locks without notification. Our only way is to walk the
* entire lock list each time we remove a lock.
*/
void
nlm_release_file(struct nlm_file *file)
{
dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
file, file->f_count);
/* Lock file table */
mutex_lock(&nlm_file_mutex);
/* If there are no more locks etc, delete the file */
if (--file->f_count == 0 && !nlm_file_inuse(file))
nlm_delete_file(file);
mutex_unlock(&nlm_file_mutex);
}
/*
* Helpers function for resource traversal
*
* nlmsvc_mark_host:
* used by the garbage collector; simply sets h_inuse.
* Always returns 0.
*
* nlmsvc_same_host:
* returns 1 iff the two hosts match. Used to release
* all resources bound to a specific host.
*
* nlmsvc_is_client:
* returns 1 iff the host is a client.
* Used by nlmsvc_invalidate_all
*/
static int
nlmsvc_mark_host(void *data, struct nlm_host *dummy)
{
struct nlm_host *host = data;
host->h_inuse = 1;
return 0;
}
static int
nlmsvc_same_host(void *data, struct nlm_host *other)
{
struct nlm_host *host = data;
return host == other;
}
static int
nlmsvc_is_client(void *data, struct nlm_host *dummy)
{
struct nlm_host *host = data;
if (host->h_server) {
/* we are destroying locks even though the client
* hasn't asked us too, so don't unmonitor the
* client
*/
if (host->h_nsmhandle)
host->h_nsmhandle->sm_sticky = 1;
return 1;
} else
return 0;
}
/*
* Mark all hosts that still hold resources
*/
void
nlmsvc_mark_resources(void)
{
dprintk("lockd: nlmsvc_mark_resources\n");
nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
}
/*
* Release all resources held by the given client
*/
void
nlmsvc_free_host_resources(struct nlm_host *host)
{
dprintk("lockd: nlmsvc_free_host_resources\n");
if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
printk(KERN_WARNING
"lockd: couldn't remove all locks held by %s\n",
host->h_name);
BUG();
}
}
/**
* nlmsvc_invalidate_all - remove all locks held for clients
*
* Release all locks held by NFS clients.
*
*/
void
nlmsvc_invalidate_all(void)
{
/*
* Previously, the code would call
* nlmsvc_free_host_resources for each client in
* turn, which is about as inefficient as it gets.
* Now we just do it once in nlm_traverse_files.
*/
nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
}
static int
nlmsvc_match_sb(void *datap, struct nlm_file *file)
{
struct super_block *sb = datap;
return sb == file->f_file->f_path.mnt->mnt_sb;
}
/**
* nlmsvc_unlock_all_by_sb - release locks held on this file system
* @sb: super block
*
* Release all locks held by clients accessing this file system.
*/
int
nlmsvc_unlock_all_by_sb(struct super_block *sb)
{
int ret;
ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
return ret ? -EIO : 0;
}
EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
static int
nlmsvc_match_ip(void *datap, struct nlm_host *host)
{
return rpc_cmp_addr(nlm_srcaddr(host), datap);
}
/**
* nlmsvc_unlock_all_by_ip - release local locks by IP address
* @server_addr: server's IP address as seen by clients
*
* Release all locks held by clients accessing this host
* via the passed in IP address.
*/
int
nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr)
{
int ret;
ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
return ret ? -EIO : 0;
}
EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip);
