mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-13 14:04:05 +08:00
eb8ed7c6ab
Most of the existing APIs have remained the same, but subsystems that access file_lock fields directly need to reach into struct file_lock_core now. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-40-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
506 lines
12 KiB
C
506 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* 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/addr.h>
|
|
#include <linux/lockd/lockd.h>
|
|
#include <linux/lockd/share.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mount.h>
|
|
#include <uapi/linux/nfs2.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 CONFIG_SUNRPC_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 = nlmsvc_file_inode(file);
|
|
|
|
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);
|
|
}
|
|
|
|
int lock_to_openmode(struct file_lock *lock)
|
|
{
|
|
return lock_is_write(lock) ? O_WRONLY : O_RDONLY;
|
|
}
|
|
|
|
/*
|
|
* Open the file. Note that if we're reexporting, for example,
|
|
* this could block the lockd thread for a while.
|
|
*
|
|
* We have to make sure we have the right credential to open
|
|
* the file.
|
|
*/
|
|
static __be32 nlm_do_fopen(struct svc_rqst *rqstp,
|
|
struct nlm_file *file, int mode)
|
|
{
|
|
struct file **fp = &file->f_file[mode];
|
|
__be32 nfserr;
|
|
|
|
if (*fp)
|
|
return 0;
|
|
nfserr = nlmsvc_ops->fopen(rqstp, &file->f_handle, fp, mode);
|
|
if (nfserr)
|
|
dprintk("lockd: open failed (error %d)\n", nfserr);
|
|
return nfserr;
|
|
}
|
|
|
|
/*
|
|
* Lookup file info. If it doesn't exist, create a file info struct
|
|
* and open a (VFS) file for the given inode.
|
|
*/
|
|
__be32
|
|
nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
|
|
struct nlm_lock *lock)
|
|
{
|
|
struct nlm_file *file;
|
|
unsigned int hash;
|
|
__be32 nfserr;
|
|
int mode;
|
|
|
|
nlm_debug_print_fh("nlm_lookup_file", &lock->fh);
|
|
|
|
hash = file_hash(&lock->fh);
|
|
mode = lock_to_openmode(&lock->fl);
|
|
|
|
/* Lock file table */
|
|
mutex_lock(&nlm_file_mutex);
|
|
|
|
hlist_for_each_entry(file, &nlm_files[hash], f_list)
|
|
if (!nfs_compare_fh(&file->f_handle, &lock->fh)) {
|
|
mutex_lock(&file->f_mutex);
|
|
nfserr = nlm_do_fopen(rqstp, file, mode);
|
|
mutex_unlock(&file->f_mutex);
|
|
goto found;
|
|
}
|
|
nlm_debug_print_fh("creating file for", &lock->fh);
|
|
|
|
nfserr = nlm_lck_denied_nolocks;
|
|
file = kzalloc(sizeof(*file), GFP_KERNEL);
|
|
if (!file)
|
|
goto out_free;
|
|
|
|
memcpy(&file->f_handle, &lock->fh, sizeof(struct nfs_fh));
|
|
mutex_init(&file->f_mutex);
|
|
INIT_HLIST_NODE(&file->f_list);
|
|
INIT_LIST_HEAD(&file->f_blocks);
|
|
|
|
nfserr = nlm_do_fopen(rqstp, file, mode);
|
|
if (nfserr)
|
|
goto out_unlock;
|
|
|
|
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++;
|
|
|
|
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);
|
|
if (file->f_file[O_RDONLY])
|
|
nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
|
|
if (file->f_file[O_WRONLY])
|
|
nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
|
|
kfree(file);
|
|
} else {
|
|
printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
|
|
}
|
|
}
|
|
|
|
static int nlm_unlock_files(struct nlm_file *file, const struct file_lock *fl)
|
|
{
|
|
struct file_lock lock;
|
|
|
|
locks_init_lock(&lock);
|
|
lock.c.flc_type = F_UNLCK;
|
|
lock.fl_start = 0;
|
|
lock.fl_end = OFFSET_MAX;
|
|
lock.c.flc_owner = fl->c.flc_owner;
|
|
lock.c.flc_pid = fl->c.flc_pid;
|
|
lock.c.flc_flags = FL_POSIX;
|
|
|
|
lock.c.flc_file = file->f_file[O_RDONLY];
|
|
if (lock.c.flc_file && vfs_lock_file(lock.c.flc_file, F_SETLK, &lock, NULL))
|
|
goto out_err;
|
|
lock.c.flc_file = file->f_file[O_WRONLY];
|
|
if (lock.c.flc_file && vfs_lock_file(lock.c.flc_file, F_SETLK, &lock, NULL))
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
pr_warn("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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 file_lock_context *flctx = locks_inode_context(inode);
|
|
struct nlm_host *lockhost;
|
|
|
|
if (!flctx || list_empty_careful(&flctx->flc_posix))
|
|
return 0;
|
|
again:
|
|
file->f_locks = 0;
|
|
spin_lock(&flctx->flc_lock);
|
|
for_each_file_lock(fl, &flctx->flc_posix) {
|
|
if (fl->fl_lmops != &nlmsvc_lock_operations)
|
|
continue;
|
|
|
|
/* update current lock count */
|
|
file->f_locks++;
|
|
|
|
lockhost = ((struct nlm_lockowner *) fl->c.flc_owner)->host;
|
|
if (match(lockhost, host)) {
|
|
|
|
spin_unlock(&flctx->flc_lock);
|
|
if (nlm_unlock_files(file, fl))
|
|
return 1;
|
|
goto again;
|
|
}
|
|
}
|
|
spin_unlock(&flctx->flc_lock);
|
|
|
|
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;
|
|
struct file_lock_context *flctx = locks_inode_context(inode);
|
|
|
|
if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
|
|
return 1;
|
|
|
|
if (flctx && !list_empty_careful(&flctx->flc_posix)) {
|
|
spin_lock(&flctx->flc_lock);
|
|
for_each_file_lock(fl, &flctx->flc_posix) {
|
|
if (fl->fl_lmops == &nlmsvc_lock_operations) {
|
|
spin_unlock(&flctx->flc_lock);
|
|
return 1;
|
|
}
|
|
}
|
|
spin_unlock(&flctx->flc_lock);
|
|
}
|
|
file->f_locks = 0;
|
|
return 0;
|
|
}
|
|
|
|
static void nlm_close_files(struct nlm_file *file)
|
|
{
|
|
if (file->f_file[O_RDONLY])
|
|
nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
|
|
if (file->f_file[O_WRONLY])
|
|
nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
|
|
}
|
|
|
|
/*
|
|
* 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 *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, 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);
|
|
nlm_close_files(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 only for those
|
|
* hosts, which passed network check.
|
|
* 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 *hint)
|
|
{
|
|
struct nlm_host *host = data;
|
|
|
|
if ((hint->net == NULL) ||
|
|
(host->net == hint->net))
|
|
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(struct net *net)
|
|
{
|
|
struct nlm_host hint;
|
|
|
|
dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0);
|
|
hint.net = net;
|
|
nlm_traverse_files(&hint, 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 == nlmsvc_file_inode(file)->i_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);
|