1 files changed, 458 insertions, 0 deletions
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
new file mode 100644
index 000000000..028fc152d
--- /dev/null
+++ b/fs/lockd/svcsubs.c
@@ -0,0 +1,458 @@
+// 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 = locks_inode(file->f_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);
+}
+
+/*
+ * 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 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, &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 file_lock_context *flctx = inode->i_flctx;
+	struct nlm_host	 *lockhost;
+
+	if (!flctx || list_empty_careful(&flctx->flc_posix))
+		return 0;
+again:
+	file->f_locks = 0;
+	spin_lock(&flctx->flc_lock);
+	list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
+		if (fl->fl_lmops != &nlmsvc_lock_operations)
+			continue;
+
+		/* update current lock count */
+		file->f_locks++;
+
+		lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host;
+		if (match(lockhost, host)) {
+			struct file_lock lock = *fl;
+
+			spin_unlock(&flctx->flc_lock);
+			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;
+		}
+	}
+	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 = inode->i_flctx;
+
+	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);
+		list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
+			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;
+}
+
+/*
+ * 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);
+				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 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 == locks_inode(file->f_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);