add idl4k kernel firmware version 1.13.0.105

kernel/fs/autofs/Kconfig

@@ -0,0 +1,21 @@
+config AUTOFS_FS
+	tristate "Kernel automounter support"
+	help
+	  The automounter is a tool to automatically mount remote file systems
+	  on demand. This implementation is partially kernel-based to reduce
+	  overhead in the already-mounted case; this is unlike the BSD
+	  automounter (amd), which is a pure user space daemon.
+
+	  To use the automounter you need the user-space tools from the autofs
+	  package; you can find the location in <file:Documentation/Changes>.
+	  You also want to answer Y to "NFS file system support", below.
+
+	  If you want to use the newer version of the automounter with more
+	  features, say N here and say Y to "Kernel automounter v4 support",
+	  below.
+
+	  To compile this support as a module, choose M here: the module will be
+	  called autofs.
+
+	  If you are not a part of a fairly large, distributed network, you
+	  probably do not need an automounter, and can say N here.

kernel/fs/autofs/Makefile

@@ -0,0 +1,7 @@
+#
+# Makefile for the linux autofs-filesystem routines.
+#
+
+obj-$(CONFIG_AUTOFS_FS) += autofs.o
+
+autofs-objs := dirhash.o init.o inode.o root.o symlink.o waitq.o

kernel/fs/autofs/autofs_i.h

@@ -0,0 +1,165 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *   
+ * linux/fs/autofs/autofs_i.h
+ *
+ *   Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/* Internal header file for autofs */
+
+#include <linux/auto_fs.h>
+
+/* This is the range of ioctl() numbers we claim as ours */
+#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
+#define AUTOFS_IOC_COUNT     32
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/wait.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/sched.h>
+
+#include <asm/current.h>
+#include <asm/uaccess.h>
+
+#ifdef DEBUG
+#define DPRINTK(D) (printk D)
+#else
+#define DPRINTK(D) ((void)0)
+#endif
+
+/*
+ * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
+ * kernel will keep the negative response cached for up to the time given
+ * here, although the time can be shorter if the kernel throws the dcache
+ * entry away.  This probably should be settable from user space.
+ */
+#define AUTOFS_NEGATIVE_TIMEOUT (60*HZ)	/* 1 minute */
+
+/* Structures associated with the root directory hash table */
+
+#define AUTOFS_HASH_SIZE 67
+
+struct autofs_dir_ent {
+	int hash;
+	char *name;
+	int len;
+	ino_t ino;
+	struct dentry *dentry;
+	/* Linked list of entries */
+	struct autofs_dir_ent *next;
+	struct autofs_dir_ent **back;
+	/* The following entries are for the expiry system */
+	unsigned long last_usage;
+	struct list_head exp;
+};
+
+struct autofs_dirhash {
+	struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
+	struct list_head expiry_head;
+};
+
+struct autofs_wait_queue {
+	wait_queue_head_t queue;
+	struct autofs_wait_queue *next;
+	autofs_wqt_t wait_queue_token;
+	/* We use the following to see what we are waiting for */
+	int hash;
+	int len;
+	char *name;
+	/* This is for status reporting upon return */
+	int status;
+	int wait_ctr;
+};
+
+struct autofs_symlink {
+	char *data;
+	int len;
+	time_t mtime;
+};
+
+#define AUTOFS_MAX_SYMLINKS 256
+
+#define AUTOFS_ROOT_INO      1
+#define AUTOFS_FIRST_SYMLINK 2
+#define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS)
+
+#define AUTOFS_SYMLINK_BITMAP_LEN \
+	((AUTOFS_MAX_SYMLINKS+((sizeof(long)*1)-1))/(sizeof(long)*8))
+
+#define AUTOFS_SBI_MAGIC 0x6d4a556d
+
+struct autofs_sb_info {
+	u32 magic;
+	struct file *pipe;
+	struct pid *oz_pgrp;
+	int catatonic;
+	struct super_block *sb;
+	unsigned long exp_timeout;
+	ino_t next_dir_ino;
+	struct autofs_wait_queue *queues; /* Wait queue pointer */
+	struct autofs_dirhash dirhash; /* Root directory hash */
+	struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS];
+	unsigned long symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN];
+};
+
+static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
+{
+	return (struct autofs_sb_info *)(sb->s_fs_info);
+}
+
+/* autofs_oz_mode(): do we see the man behind the curtain?  (The
+   processes which do manipulations for us in user space sees the raw
+   filesystem without "magic".) */
+
+static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
+	return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
+}
+
+/* Hash operations */
+
+void autofs_initialize_hash(struct autofs_dirhash *);
+struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
+void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
+void autofs_hash_delete(struct autofs_dir_ent *);
+struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
+void autofs_hash_dputall(struct autofs_dirhash *);
+void autofs_hash_nuke(struct autofs_sb_info *);
+
+/* Expiration-handling functions */
+
+void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
+struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);
+
+/* Operations structures */
+
+extern const struct inode_operations autofs_root_inode_operations;
+extern const struct inode_operations autofs_symlink_inode_operations;
+extern const struct file_operations autofs_root_operations;
+
+/* Initializing function */
+
+int autofs_fill_super(struct super_block *, void *, int);
+void autofs_kill_sb(struct super_block *sb);
+struct inode *autofs_iget(struct super_block *, unsigned long);
+
+/* Queue management functions */
+
+int autofs_wait(struct autofs_sb_info *,struct qstr *);
+int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
+void autofs_catatonic_mode(struct autofs_sb_info *);
+
+#ifdef DEBUG
+void autofs_say(const char *name, int len);
+#else
+#define autofs_say(n,l) ((void)0)
+#endif

kernel/fs/autofs/dirhash.c

@@ -0,0 +1,250 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/autofs/dirhash.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include "autofs_i.h"
+
+/* Functions for maintenance of expiry queue */
+
+static void autofs_init_usage(struct autofs_dirhash *dh,
+			      struct autofs_dir_ent *ent)
+{
+	list_add_tail(&ent->exp, &dh->expiry_head);
+	ent->last_usage = jiffies;
+}
+
+static void autofs_delete_usage(struct autofs_dir_ent *ent)
+{
+	list_del(&ent->exp);
+}
+
+void autofs_update_usage(struct autofs_dirhash *dh,
+			 struct autofs_dir_ent *ent)
+{
+	autofs_delete_usage(ent);   /* Unlink from current position */
+	autofs_init_usage(dh,ent);  /* Relink at queue tail */
+}
+
+struct autofs_dir_ent *autofs_expire(struct super_block *sb,
+				     struct autofs_sb_info *sbi,
+				     struct vfsmount *mnt)
+{
+	struct autofs_dirhash *dh = &sbi->dirhash;
+	struct autofs_dir_ent *ent;
+	unsigned long timeout = sbi->exp_timeout;
+
+	while (1) {
+		struct path path;
+		int umount_ok;
+
+		if ( list_empty(&dh->expiry_head) || sbi->catatonic )
+			return NULL;	/* No entries */
+		/* We keep the list sorted by last_usage and want old stuff */
+		ent = list_entry(dh->expiry_head.next, struct autofs_dir_ent, exp);
+		if (jiffies - ent->last_usage < timeout)
+			break;
+		/* Move to end of list in case expiry isn't desirable */
+		autofs_update_usage(dh, ent);
+
+		/* Check to see that entry is expirable */
+		if ( ent->ino < AUTOFS_FIRST_DIR_INO )
+			return ent; /* Symlinks are always expirable */
+
+		/* Get the dentry for the autofs subdirectory */
+		path.dentry = ent->dentry;
+
+		if (!path.dentry) {
+			/* Should only happen in catatonic mode */
+			printk("autofs: dentry == NULL but inode range is directory, entry %s\n", ent->name);
+			autofs_delete_usage(ent);
+			continue;
+		}
+
+		if (!path.dentry->d_inode) {
+			dput(path.dentry);
+			printk("autofs: negative dentry on expiry queue: %s\n",
+			       ent->name);
+			autofs_delete_usage(ent);
+			continue;
+		}
+
+		/* Make sure entry is mounted and unused; note that dentry will
+		   point to the mounted-on-top root. */
+		if (!S_ISDIR(path.dentry->d_inode->i_mode) ||
+		    !d_mountpoint(path.dentry)) {
+			DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));
+			continue;
+		}
+		path.mnt = mnt;
+		path_get(&path);
+		if (!follow_down(&path)) {
+			path_put(&path);
+			DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));
+			continue;
+		}
+		while (d_mountpoint(path.dentry) && follow_down(&path))
+			;
+		umount_ok = may_umount(path.mnt);
+		path_put(&path);
+
+		if (umount_ok) {
+			DPRINTK(("autofs: signaling expire on %s\n", ent->name));
+			return ent; /* Expirable! */
+		}
+		DPRINTK(("autofs: didn't expire due to may_umount: %s\n", ent->name));
+	}
+	return NULL;		/* No expirable entries */
+}
+
+void autofs_initialize_hash(struct autofs_dirhash *dh) {
+	memset(&dh->h, 0, AUTOFS_HASH_SIZE*sizeof(struct autofs_dir_ent *));
+	INIT_LIST_HEAD(&dh->expiry_head);
+}
+
+struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *dh, struct qstr *name)
+{
+	struct autofs_dir_ent *dhn;
+
+	DPRINTK(("autofs_hash_lookup: hash = 0x%08x, name = ", name->hash));
+	autofs_say(name->name,name->len);
+
+	for ( dhn = dh->h[(unsigned) name->hash % AUTOFS_HASH_SIZE] ; dhn ; dhn = dhn->next ) {
+		if ( name->hash == dhn->hash &&
+		     name->len == dhn->len &&
+		     !memcmp(name->name, dhn->name, name->len) )
+			break;
+	}
+
+	return dhn;
+}
+
+void autofs_hash_insert(struct autofs_dirhash *dh, struct autofs_dir_ent *ent)
+{
+	struct autofs_dir_ent **dhnp;
+
+	DPRINTK(("autofs_hash_insert: hash = 0x%08x, name = ", ent->hash));
+	autofs_say(ent->name,ent->len);
+
+	autofs_init_usage(dh,ent);
+	if (ent->dentry)
+		dget(ent->dentry);
+
+	dhnp = &dh->h[(unsigned) ent->hash % AUTOFS_HASH_SIZE];
+	ent->next = *dhnp;
+	ent->back = dhnp;
+	*dhnp = ent;
+	if ( ent->next )
+		ent->next->back = &(ent->next);
+}
+
+void autofs_hash_delete(struct autofs_dir_ent *ent)
+{
+	*(ent->back) = ent->next;
+	if ( ent->next )
+		ent->next->back = ent->back;
+
+	autofs_delete_usage(ent);
+
+	if ( ent->dentry )
+		dput(ent->dentry);
+	kfree(ent->name);
+	kfree(ent);
+}
+
+/*
+ * Used by readdir().  We must validate "ptr", so we can't simply make it
+ * a pointer.  Values below 0xffff are reserved; calling with any value
+ * <= 0x10000 will return the first entry found.
+ *
+ * "last" can be NULL or the value returned by the last search *if* we
+ * want the next sequential entry.
+ */
+struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *dh,
+					off_t *ptr, struct autofs_dir_ent *last)
+{
+	int bucket, ecount, i;
+	struct autofs_dir_ent *ent;
+
+	bucket = (*ptr >> 16) - 1;
+	ecount = *ptr & 0xffff;
+
+	if ( bucket < 0 ) {
+		bucket = ecount = 0;
+	} 
+
+	DPRINTK(("autofs_hash_enum: bucket %d, entry %d\n", bucket, ecount));
+
+	ent = last ? last->next : NULL;
+
+	if ( ent ) {
+		ecount++;
+	} else {
+		while  ( bucket < AUTOFS_HASH_SIZE ) {
+			ent = dh->h[bucket];
+			for ( i = ecount ; ent && i ; i-- )
+				ent = ent->next;
+			
+			if (ent) {
+				ecount++; /* Point to *next* entry */
+				break;
+			}
+			
+			bucket++; ecount = 0;
+		}
+	}
+
+#ifdef DEBUG
+	if ( !ent )
+		printk("autofs_hash_enum: nothing found\n");
+	else {
+		printk("autofs_hash_enum: found hash %08x, name", ent->hash);
+		autofs_say(ent->name,ent->len);
+	}
+#endif
+
+	*ptr = ((bucket+1) << 16) + ecount;
+	return ent;
+}
+
+/* Iterate over all the ents, and remove all dentry pointers.  Used on
+   entering catatonic mode, in order to make the filesystem unmountable. */
+void autofs_hash_dputall(struct autofs_dirhash *dh)
+{
+	int i;
+	struct autofs_dir_ent *ent;
+
+	for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) {
+		for ( ent = dh->h[i] ; ent ; ent = ent->next ) {
+			if ( ent->dentry ) {
+				dput(ent->dentry);
+				ent->dentry = NULL;
+			}
+		}
+	}
+}
+
+/* Delete everything.  This is used on filesystem destruction, so we
+   make no attempt to keep the pointers valid */
+void autofs_hash_nuke(struct autofs_sb_info *sbi)
+{
+	int i;
+	struct autofs_dir_ent *ent, *nent;
+
+	for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) {
+		for ( ent = sbi->dirhash.h[i] ; ent ; ent = nent ) {
+			nent = ent->next;
+			if ( ent->dentry )
+				dput(ent->dentry);
+			kfree(ent->name);
+			kfree(ent);
+		}
+	}
+}

kernel/fs/autofs/init.c

@@ -0,0 +1,52 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/autofs/init.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include "autofs_i.h"
+
+static int autofs_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+{
+	return get_sb_nodev(fs_type, flags, data, autofs_fill_super, mnt);
+}
+
+static struct file_system_type autofs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "autofs",
+	.get_sb		= autofs_get_sb,
+	.kill_sb	= autofs_kill_sb,
+};
+
+static int __init init_autofs_fs(void)
+{
+	return register_filesystem(&autofs_fs_type);
+}
+
+static void __exit exit_autofs_fs(void)
+{
+	unregister_filesystem(&autofs_fs_type);
+}
+
+module_init(init_autofs_fs);
+module_exit(exit_autofs_fs);
+
+#ifdef DEBUG
+void autofs_say(const char *name, int len)
+{
+	printk("(%d: ", len);
+	while ( len-- )
+		printk("%c", *name++);
+	printk(")\n");
+}
+#endif
+MODULE_LICENSE("GPL");

kernel/fs/autofs/inode.c

@@ -0,0 +1,288 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/autofs/inode.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/parser.h>
+#include <linux/bitops.h>
+#include <linux/magic.h>
+#include "autofs_i.h"
+#include <linux/module.h>
+
+void autofs_kill_sb(struct super_block *sb)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(sb);
+	unsigned int n;
+
+	/*
+	 * In the event of a failure in get_sb_nodev the superblock
+	 * info is not present so nothing else has been setup, so
+	 * just call kill_anon_super when we are called from
+	 * deactivate_super.
+	 */
+	if (!sbi)
+		goto out_kill_sb;
+
+	if (!sbi->catatonic)
+		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
+
+	put_pid(sbi->oz_pgrp);
+
+	autofs_hash_nuke(sbi);
+	for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) {
+		if (test_bit(n, sbi->symlink_bitmap))
+			kfree(sbi->symlink[n].data);
+	}
+
+	kfree(sb->s_fs_info);
+
+out_kill_sb:
+	DPRINTK(("autofs: shutting down\n"));
+	kill_anon_super(sb);
+}
+
+static const struct super_operations autofs_sops = {
+	.statfs		= simple_statfs,
+	.show_options	= generic_show_options,
+};
+
+enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
+
+static const match_table_t autofs_tokens = {
+	{Opt_fd, "fd=%u"},
+	{Opt_uid, "uid=%u"},
+	{Opt_gid, "gid=%u"},
+	{Opt_pgrp, "pgrp=%u"},
+	{Opt_minproto, "minproto=%u"},
+	{Opt_maxproto, "maxproto=%u"},
+	{Opt_err, NULL}
+};
+
+static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
+		pid_t *pgrp, int *minproto, int *maxproto)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+
+	*uid = current_uid();
+	*gid = current_gid();
+	*pgrp = task_pgrp_nr(current);
+
+	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
+
+	*pipefd = -1;
+
+	if (!options)
+		return 1;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+
+		token = match_token(p, autofs_tokens, args);
+		switch (token) {
+		case Opt_fd:
+			if (match_int(&args[0], &option))
+				return 1;
+			*pipefd = option;
+			break;
+		case Opt_uid:
+			if (match_int(&args[0], &option))
+				return 1;
+			*uid = option;
+			break;
+		case Opt_gid:
+			if (match_int(&args[0], &option))
+				return 1;
+			*gid = option;
+			break;
+		case Opt_pgrp:
+			if (match_int(&args[0], &option))
+				return 1;
+			*pgrp = option;
+			break;
+		case Opt_minproto:
+			if (match_int(&args[0], &option))
+				return 1;
+			*minproto = option;
+			break;
+		case Opt_maxproto:
+			if (match_int(&args[0], &option))
+				return 1;
+			*maxproto = option;
+			break;
+		default:
+			return 1;
+		}
+	}
+	return (*pipefd < 0);
+}
+
+int autofs_fill_super(struct super_block *s, void *data, int silent)
+{
+	struct inode * root_inode;
+	struct dentry * root;
+	struct file * pipe;
+	int pipefd;
+	struct autofs_sb_info *sbi;
+	int minproto, maxproto;
+	pid_t pgid;
+
+	save_mount_options(s, data);
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		goto fail_unlock;
+	DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
+
+	s->s_fs_info = sbi;
+	sbi->magic = AUTOFS_SBI_MAGIC;
+	sbi->pipe = NULL;
+	sbi->catatonic = 1;
+	sbi->exp_timeout = 0;
+	autofs_initialize_hash(&sbi->dirhash);
+	sbi->queues = NULL;
+	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
+	sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
+	s->s_blocksize = 1024;
+	s->s_blocksize_bits = 10;
+	s->s_magic = AUTOFS_SUPER_MAGIC;
+	s->s_op = &autofs_sops;
+	s->s_time_gran = 1;
+	sbi->sb = s;
+
+	root_inode = autofs_iget(s, AUTOFS_ROOT_INO);
+	if (IS_ERR(root_inode))
+		goto fail_free;
+	root = d_alloc_root(root_inode);
+	pipe = NULL;
+
+	if (!root)
+		goto fail_iput;
+
+	/* Can this call block?  - WTF cares? s is locked. */
+	if (parse_options(data, &pipefd, &root_inode->i_uid,
+				&root_inode->i_gid, &pgid, &minproto,
+				&maxproto)) {
+		printk("autofs: called with bogus options\n");
+		goto fail_dput;
+	}
+
+	/* Couldn't this be tested earlier? */
+	if (minproto > AUTOFS_PROTO_VERSION ||
+	     maxproto < AUTOFS_PROTO_VERSION) {
+		printk("autofs: kernel does not match daemon version\n");
+		goto fail_dput;
+	}
+
+	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, pgid));
+	sbi->oz_pgrp = find_get_pid(pgid);
+
+	if (!sbi->oz_pgrp) {
+		printk("autofs: could not find process group %d\n", pgid);
+		goto fail_dput;
+	}
+
+	pipe = fget(pipefd);
+	
+	if (!pipe) {
+		printk("autofs: could not open pipe file descriptor\n");
+		goto fail_put_pid;
+	}
+
+	if (!pipe->f_op || !pipe->f_op->write)
+		goto fail_fput;
+	sbi->pipe = pipe;
+	sbi->catatonic = 0;
+
+	/*
+	 * Success! Install the root dentry now to indicate completion.
+	 */
+	s->s_root = root;
+	return 0;
+
+fail_fput:
+	printk("autofs: pipe file descriptor does not contain proper ops\n");
+	fput(pipe);
+fail_put_pid:
+	put_pid(sbi->oz_pgrp);
+fail_dput:
+	dput(root);
+	goto fail_free;
+fail_iput:
+	printk("autofs: get root dentry failed\n");
+	iput(root_inode);
+fail_free:
+	kfree(sbi);
+	s->s_fs_info = NULL;
+fail_unlock:
+	return -EINVAL;
+}
+
+struct inode *autofs_iget(struct super_block *sb, unsigned long ino)
+{
+	unsigned int n;
+	struct autofs_sb_info *sbi = autofs_sbi(sb);
+	struct inode *inode;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+
+	/* Initialize to the default case (stub directory) */
+
+	inode->i_op = &simple_dir_inode_operations;
+	inode->i_fop = &simple_dir_operations;
+	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
+	inode->i_nlink = 2;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+
+	if (ino == AUTOFS_ROOT_INO) {
+		inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
+		inode->i_op = &autofs_root_inode_operations;
+		inode->i_fop = &autofs_root_operations;
+		goto done;
+	} 
+	
+	inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
+	inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
+	
+	if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) {
+		/* Symlink inode - should be in symlink list */
+		struct autofs_symlink *sl;
+
+		n = ino - AUTOFS_FIRST_SYMLINK;
+		if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
+			printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
+			goto done;
+		}
+		
+		inode->i_op = &autofs_symlink_inode_operations;
+		sl = &sbi->symlink[n];
+		inode->i_private = sl;
+		inode->i_mode = S_IFLNK | S_IRWXUGO;
+		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
+		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
+		inode->i_size = sl->len;
+		inode->i_nlink = 1;
+	}
+
+done:
+	unlock_new_inode(inode);
+	return inode;
+}

kernel/fs/autofs/root.c

@@ -0,0 +1,580 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/autofs/root.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/smp_lock.h>
+#include "autofs_i.h"
+
+static int autofs_root_readdir(struct file *,void *,filldir_t);
+static struct dentry *autofs_root_lookup(struct inode *,struct dentry *, struct nameidata *);
+static int autofs_root_symlink(struct inode *,struct dentry *,const char *);
+static int autofs_root_unlink(struct inode *,struct dentry *);
+static int autofs_root_rmdir(struct inode *,struct dentry *);
+static int autofs_root_mkdir(struct inode *,struct dentry *,int);
+static int autofs_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
+
+const struct file_operations autofs_root_operations = {
+	.read		= generic_read_dir,
+	.readdir	= autofs_root_readdir,
+	.ioctl		= autofs_root_ioctl,
+};
+
+const struct inode_operations autofs_root_inode_operations = {
+        .lookup		= autofs_root_lookup,
+        .unlink		= autofs_root_unlink,
+        .symlink	= autofs_root_symlink,
+        .mkdir		= autofs_root_mkdir,
+        .rmdir		= autofs_root_rmdir,
+};
+
+static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	struct autofs_dir_ent *ent = NULL;
+	struct autofs_dirhash *dirhash;
+	struct autofs_sb_info *sbi;
+	struct inode * inode = filp->f_path.dentry->d_inode;
+	off_t onr, nr;
+
+	lock_kernel();
+
+	sbi = autofs_sbi(inode->i_sb);
+	dirhash = &sbi->dirhash;
+	nr = filp->f_pos;
+
+	switch(nr)
+	{
+	case 0:
+		if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
+			goto out;
+		filp->f_pos = ++nr;
+		/* fall through */
+	case 1:
+		if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
+			goto out;
+		filp->f_pos = ++nr;
+		/* fall through */
+	default:
+		while (onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent)) {
+			if (!ent->dentry || d_mountpoint(ent->dentry)) {
+				if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
+					goto out;
+				filp->f_pos = nr;
+			}
+		}
+		break;
+	}
+
+out:
+	unlock_kernel();
+	return 0;
+}
+
+static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
+{
+	struct inode * inode;
+	struct autofs_dir_ent *ent;
+	int status = 0;
+
+	if (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) {
+		do {
+			if (status && dentry->d_inode) {
+				if (status != -ENOENT)
+					printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
+				return 0; /* Try to get the kernel to invalidate this dentry */
+			}
+
+			/* Turn this into a real negative dentry? */
+			if (status == -ENOENT) {
+				dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
+				dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+				return 1;
+			} else if (status) {
+				/* Return a negative dentry, but leave it "pending" */
+				return 1;
+			}
+			status = autofs_wait(sbi, &dentry->d_name);
+		} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)));
+	}
+
+	/* Abuse this field as a pointer to the directory entry, used to
+	   find the expire list pointers */
+	dentry->d_time = (unsigned long) ent;
+	
+	if (!dentry->d_inode) {
+		inode = autofs_iget(sb, ent->ino);
+		if (IS_ERR(inode)) {
+			/* Failed, but leave pending for next time */
+			return 1;
+		}
+		dentry->d_inode = inode;
+	}
+
+	/* If this is a directory that isn't a mount point, bitch at the
+	   daemon and fix it in user space */
+	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
+		return !autofs_wait(sbi, &dentry->d_name);
+	}
+
+	/* We don't update the usages for the autofs daemon itself, this
+	   is necessary for recursive autofs mounts */
+	if (!autofs_oz_mode(sbi)) {
+		autofs_update_usage(&sbi->dirhash,ent);
+	}
+
+	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+	return 1;
+}
+
+
+/*
+ * Revalidate is called on every cache lookup.  Some of those
+ * cache lookups may actually happen while the dentry is not
+ * yet completely filled in, and revalidate has to delay such
+ * lookups..
+ */
+static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
+{
+	struct inode * dir;
+	struct autofs_sb_info *sbi;
+	struct autofs_dir_ent *ent;
+	int res;
+
+	lock_kernel();
+	dir = dentry->d_parent->d_inode;
+	sbi = autofs_sbi(dir->i_sb);
+
+	/* Pending dentry */
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
+		if (autofs_oz_mode(sbi))
+			res = 1;
+		else
+			res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
+		unlock_kernel();
+		return res;
+	}
+
+	/* Negative dentry.. invalidate if "old" */
+	if (!dentry->d_inode) {
+		unlock_kernel();
+		return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
+	}
+		
+	/* Check for a non-mountpoint directory */
+	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
+		if (autofs_oz_mode(sbi))
+			res = 1;
+		else
+			res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
+		unlock_kernel();
+		return res;
+	}
+
+	/* Update the usage list */
+	if (!autofs_oz_mode(sbi)) {
+		ent = (struct autofs_dir_ent *) dentry->d_time;
+		if (ent)
+			autofs_update_usage(&sbi->dirhash,ent);
+	}
+	unlock_kernel();
+	return 1;
+}
+
+static const struct dentry_operations autofs_dentry_operations = {
+	.d_revalidate	= autofs_revalidate,
+};
+
+static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+	struct autofs_sb_info *sbi;
+	int oz_mode;
+
+	DPRINTK(("autofs_root_lookup: name = "));
+	lock_kernel();
+	autofs_say(dentry->d_name.name,dentry->d_name.len);
+
+	if (dentry->d_name.len > NAME_MAX) {
+		unlock_kernel();
+		return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
+	}
+
+	sbi = autofs_sbi(dir->i_sb);
+
+	oz_mode = autofs_oz_mode(sbi);
+	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
+				"oz_mode = %d\n", task_pid_nr(current),
+				task_pgrp_nr(current), sbi->catatonic,
+				oz_mode));
+
+	/*
+	 * Mark the dentry incomplete, but add it. This is needed so
+	 * that the VFS layer knows about the dentry, and we can count
+	 * on catching any lookups through the revalidate.
+	 *
+	 * Let all the hard work be done by the revalidate function that
+	 * needs to be able to do this anyway..
+	 *
+	 * We need to do this before we release the directory semaphore.
+	 */
+	dentry->d_op = &autofs_dentry_operations;
+	dentry->d_flags |= DCACHE_AUTOFS_PENDING;
+	d_add(dentry, NULL);
+
+	mutex_unlock(&dir->i_mutex);
+	autofs_revalidate(dentry, nd);
+	mutex_lock(&dir->i_mutex);
+
+	/*
+	 * If we are still pending, check if we had to handle
+	 * a signal. If so we can force a restart..
+	 */
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
+		/* See if we were interrupted */
+		if (signal_pending(current)) {
+			sigset_t *sigset = &current->pending.signal;
+			if (sigismember (sigset, SIGKILL) ||
+			    sigismember (sigset, SIGQUIT) ||
+			    sigismember (sigset, SIGINT)) {
+				unlock_kernel();
+				return ERR_PTR(-ERESTARTNOINTR);
+			}
+		}
+	}
+	unlock_kernel();
+
+	/*
+	 * If this dentry is unhashed, then we shouldn't honour this
+	 * lookup even if the dentry is positive.  Returning ENOENT here
+	 * doesn't do the right thing for all system calls, but it should
+	 * be OK for the operations we permit from an autofs.
+	 */
+	if (dentry->d_inode && d_unhashed(dentry))
+		return ERR_PTR(-ENOENT);
+
+	return NULL;
+}
+
+static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+	struct autofs_dirhash *dh = &sbi->dirhash;
+	struct autofs_dir_ent *ent;
+	unsigned int n;
+	int slsize;
+	struct autofs_symlink *sl;
+	struct inode *inode;
+
+	DPRINTK(("autofs_root_symlink: %s <- ", symname));
+	autofs_say(dentry->d_name.name,dentry->d_name.len);
+
+	lock_kernel();
+	if (!autofs_oz_mode(sbi)) {
+		unlock_kernel();
+		return -EACCES;
+	}
+
+	if (autofs_hash_lookup(dh, &dentry->d_name)) {
+		unlock_kernel();
+		return -EEXIST;
+	}
+
+	n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
+	if (n >= AUTOFS_MAX_SYMLINKS) {
+		unlock_kernel();
+		return -ENOSPC;
+	}
+
+	set_bit(n,sbi->symlink_bitmap);
+	sl = &sbi->symlink[n];
+	sl->len = strlen(symname);
+	sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
+	if (!sl->data) {
+		clear_bit(n,sbi->symlink_bitmap);
+		unlock_kernel();
+		return -ENOSPC;
+	}
+
+	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
+	if (!ent) {
+		kfree(sl->data);
+		clear_bit(n,sbi->symlink_bitmap);
+		unlock_kernel();
+		return -ENOSPC;
+	}
+
+	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
+	if (!ent->name) {
+		kfree(sl->data);
+		kfree(ent);
+		clear_bit(n,sbi->symlink_bitmap);
+		unlock_kernel();
+		return -ENOSPC;
+	}
+
+	memcpy(sl->data,symname,slsize);
+	sl->mtime = get_seconds();
+
+	ent->ino = AUTOFS_FIRST_SYMLINK + n;
+	ent->hash = dentry->d_name.hash;
+	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
+	ent->dentry = NULL;	/* We don't keep the dentry for symlinks */
+
+	autofs_hash_insert(dh,ent);
+
+	inode = autofs_iget(dir->i_sb, ent->ino);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	d_instantiate(dentry, inode);
+	unlock_kernel();
+	return 0;
+}
+
+/*
+ * NOTE!
+ *
+ * Normal filesystems would do a "d_delete()" to tell the VFS dcache
+ * that the file no longer exists. However, doing that means that the
+ * VFS layer can turn the dentry into a negative dentry, which we
+ * obviously do not want (we're dropping the entry not because it
+ * doesn't exist, but because it has timed out).
+ *
+ * Also see autofs_root_rmdir()..
+ */
+static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+	struct autofs_dirhash *dh = &sbi->dirhash;
+	struct autofs_dir_ent *ent;
+	unsigned int n;
+
+	/* This allows root to remove symlinks */
+	lock_kernel();
+	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) {
+		unlock_kernel();
+		return -EACCES;
+	}
+
+	ent = autofs_hash_lookup(dh, &dentry->d_name);
+	if (!ent) {
+		unlock_kernel();
+		return -ENOENT;
+	}
+
+	n = ent->ino - AUTOFS_FIRST_SYMLINK;
+	if (n >= AUTOFS_MAX_SYMLINKS) {
+		unlock_kernel();
+		return -EISDIR;	/* It's a directory, dummy */
+	}
+	if (!test_bit(n,sbi->symlink_bitmap)) {
+		unlock_kernel();
+		return -EINVAL;	/* Nonexistent symlink?  Shouldn't happen */
+	}
+	
+	dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
+	autofs_hash_delete(ent);
+	clear_bit(n,sbi->symlink_bitmap);
+	kfree(sbi->symlink[n].data);
+	d_drop(dentry);
+	
+	unlock_kernel();
+	return 0;
+}
+
+static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+	struct autofs_dirhash *dh = &sbi->dirhash;
+	struct autofs_dir_ent *ent;
+
+	lock_kernel();
+	if (!autofs_oz_mode(sbi)) {
+		unlock_kernel();
+		return -EACCES;
+	}
+
+	ent = autofs_hash_lookup(dh, &dentry->d_name);
+	if (!ent) {
+		unlock_kernel();
+		return -ENOENT;
+	}
+
+	if ((unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO) {
+		unlock_kernel();
+		return -ENOTDIR; /* Not a directory */
+	}
+
+	if (ent->dentry != dentry) {
+		printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
+	}
+
+	dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
+	autofs_hash_delete(ent);
+	drop_nlink(dir);
+	d_drop(dentry);
+	unlock_kernel();
+
+	return 0;
+}
+
+static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+	struct autofs_dirhash *dh = &sbi->dirhash;
+	struct autofs_dir_ent *ent;
+	struct inode *inode;
+	ino_t ino;
+
+	lock_kernel();
+	if (!autofs_oz_mode(sbi)) {
+		unlock_kernel();
+		return -EACCES;
+	}
+
+	ent = autofs_hash_lookup(dh, &dentry->d_name);
+	if (ent) {
+		unlock_kernel();
+		return -EEXIST;
+	}
+
+	if (sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO) {
+		printk("autofs: Out of inode numbers -- what the heck did you do??\n");
+		unlock_kernel();
+		return -ENOSPC;
+	}
+	ino = sbi->next_dir_ino++;
+
+	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
+	if (!ent) {
+		unlock_kernel();
+		return -ENOSPC;
+	}
+
+	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
+	if (!ent->name) {
+		kfree(ent);
+		unlock_kernel();
+		return -ENOSPC;
+	}
+
+	ent->hash = dentry->d_name.hash;
+	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
+	ent->ino = ino;
+	ent->dentry = dentry;
+	autofs_hash_insert(dh,ent);
+
+	inc_nlink(dir);
+
+	inode = autofs_iget(dir->i_sb, ino);
+	if (IS_ERR(inode)) {
+		drop_nlink(dir);
+		return PTR_ERR(inode);
+	}
+
+	d_instantiate(dentry, inode);
+	unlock_kernel();
+
+	return 0;
+}
+
+/* Get/set timeout ioctl() operation */
+static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
+					 unsigned long __user *p)
+{
+	unsigned long ntimeout;
+
+	if (get_user(ntimeout, p) ||
+	    put_user(sbi->exp_timeout / HZ, p))
+		return -EFAULT;
+
+	if (ntimeout > ULONG_MAX/HZ)
+		sbi->exp_timeout = 0;
+	else
+		sbi->exp_timeout = ntimeout * HZ;
+
+	return 0;
+}
+
+/* Return protocol version */
+static inline int autofs_get_protover(int __user *p)
+{
+	return put_user(AUTOFS_PROTO_VERSION, p);
+}
+
+/* Perform an expiry operation */
+static inline int autofs_expire_run(struct super_block *sb,
+				    struct autofs_sb_info *sbi,
+				    struct vfsmount *mnt,
+				    struct autofs_packet_expire __user *pkt_p)
+{
+	struct autofs_dir_ent *ent;
+	struct autofs_packet_expire pkt;
+
+	memset(&pkt,0,sizeof pkt);
+
+	pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
+	pkt.hdr.type = autofs_ptype_expire;
+
+	if (!sbi->exp_timeout || !(ent = autofs_expire(sb,sbi,mnt)))
+		return -EAGAIN;
+
+	pkt.len = ent->len;
+	memcpy(pkt.name, ent->name, pkt.len);
+	pkt.name[pkt.len] = '\0';
+
+	if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * ioctl()'s on the root directory is the chief method for the daemon to
+ * generate kernel reactions
+ */
+static int autofs_root_ioctl(struct inode *inode, struct file *filp,
+			     unsigned int cmd, unsigned long arg)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
+	void __user *argp = (void __user *)arg;
+
+	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));
+
+	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
+	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
+		return -ENOTTY;
+	
+	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	
+	switch(cmd) {
+	case AUTOFS_IOC_READY:	/* Wait queue: go ahead and retry */
+		return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
+	case AUTOFS_IOC_FAIL:	/* Wait queue: fail with ENOENT */
+		return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
+	case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
+		autofs_catatonic_mode(sbi);
+		return 0;
+	case AUTOFS_IOC_PROTOVER: /* Get protocol version */
+		return autofs_get_protover(argp);
+	case AUTOFS_IOC_SETTIMEOUT:
+		return autofs_get_set_timeout(sbi, argp);
+	case AUTOFS_IOC_EXPIRE:
+		return autofs_expire_run(inode->i_sb, sbi, filp->f_path.mnt,
+					 argp);
+	default:
+		return -ENOSYS;
+	}
+}

kernel/fs/autofs/symlink.c

@@ -0,0 +1,26 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/autofs/symlink.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include "autofs_i.h"
+
+/* Nothing to release.. */
+static void *autofs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	char *s=((struct autofs_symlink *)dentry->d_inode->i_private)->data;
+	nd_set_link(nd, s);
+	return NULL;
+}
+
+const struct inode_operations autofs_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= autofs_follow_link
+};

kernel/fs/autofs/waitq.c

@@ -0,0 +1,205 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/autofs/waitq.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/signal.h>
+#include <linux/file.h>
+#include "autofs_i.h"
+
+/* We make this a static variable rather than a part of the superblock; it
+   is better if we don't reassign numbers easily even across filesystems */
+static autofs_wqt_t autofs_next_wait_queue = 1;
+
+/* These are the signals we allow interrupting a pending mount */
+#define SHUTDOWN_SIGS	(sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT))
+
+void autofs_catatonic_mode(struct autofs_sb_info *sbi)
+{
+	struct autofs_wait_queue *wq, *nwq;
+
+	DPRINTK(("autofs: entering catatonic mode\n"));
+
+	sbi->catatonic = 1;
+	wq = sbi->queues;
+	sbi->queues = NULL;	/* Erase all wait queues */
+	while ( wq ) {
+		nwq = wq->next;
+		wq->status = -ENOENT; /* Magic is gone - report failure */
+		kfree(wq->name);
+		wq->name = NULL;
+		wake_up(&wq->queue);
+		wq = nwq;
+	}
+	fput(sbi->pipe);	/* Close the pipe */
+	sbi->pipe = NULL;
+	autofs_hash_dputall(&sbi->dirhash); /* Remove all dentry pointers */
+}
+
+static int autofs_write(struct file *file, const void *addr, int bytes)
+{
+	unsigned long sigpipe, flags;
+	mm_segment_t fs;
+	const char *data = (const char *)addr;
+	ssize_t wr = 0;
+
+	/** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/
+
+	sigpipe = sigismember(&current->pending.signal, SIGPIPE);
+
+	/* Save pointer to user space and point back to kernel space */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	while (bytes &&
+	       (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
+		data += wr;
+		bytes -= wr;
+	}
+
+	set_fs(fs);
+
+	/* Keep the currently executing process from receiving a
+	   SIGPIPE unless it was already supposed to get one */
+	if (wr == -EPIPE && !sigpipe) {
+		spin_lock_irqsave(&current->sighand->siglock, flags);
+		sigdelset(&current->pending.signal, SIGPIPE);
+		recalc_sigpending();
+		spin_unlock_irqrestore(&current->sighand->siglock, flags);
+	}
+
+	return (bytes > 0);
+}
+	
+static void autofs_notify_daemon(struct autofs_sb_info *sbi, struct autofs_wait_queue *wq)
+{
+	struct autofs_packet_missing pkt;
+
+	DPRINTK(("autofs_wait: wait id = 0x%08lx, name = ", wq->wait_queue_token));
+	autofs_say(wq->name,wq->len);
+
+	memset(&pkt,0,sizeof pkt); /* For security reasons */
+
+	pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
+	pkt.hdr.type = autofs_ptype_missing;
+	pkt.wait_queue_token = wq->wait_queue_token;
+	pkt.len = wq->len;
+        memcpy(pkt.name, wq->name, pkt.len);
+	pkt.name[pkt.len] = '\0';
+
+	if ( autofs_write(sbi->pipe,&pkt,sizeof(struct autofs_packet_missing)) )
+		autofs_catatonic_mode(sbi);
+}
+
+int autofs_wait(struct autofs_sb_info *sbi, struct qstr *name)
+{
+	struct autofs_wait_queue *wq;
+	int status;
+
+	/* In catatonic mode, we don't wait for nobody */
+	if ( sbi->catatonic )
+		return -ENOENT;
+	
+	/* We shouldn't be able to get here, but just in case */
+	if ( name->len > NAME_MAX )
+		return -ENOENT;
+
+	for ( wq = sbi->queues ; wq ; wq = wq->next ) {
+		if ( wq->hash == name->hash &&
+		     wq->len == name->len &&
+		     wq->name && !memcmp(wq->name,name->name,name->len) )
+			break;
+	}
+	
+	if ( !wq ) {
+		/* Create a new wait queue */
+		wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
+		if ( !wq )
+			return -ENOMEM;
+
+		wq->name = kmalloc(name->len,GFP_KERNEL);
+		if ( !wq->name ) {
+			kfree(wq);
+			return -ENOMEM;
+		}
+		wq->wait_queue_token = autofs_next_wait_queue++;
+		init_waitqueue_head(&wq->queue);
+		wq->hash = name->hash;
+		wq->len = name->len;
+		wq->status = -EINTR; /* Status return if interrupted */
+		memcpy(wq->name, name->name, name->len);
+		wq->next = sbi->queues;
+		sbi->queues = wq;
+
+		/* autofs_notify_daemon() may block */
+		wq->wait_ctr = 2;
+		autofs_notify_daemon(sbi,wq);
+	} else
+		wq->wait_ctr++;
+
+	/* wq->name is NULL if and only if the lock is already released */
+
+	if ( sbi->catatonic ) {
+		/* We might have slept, so check again for catatonic mode */
+		wq->status = -ENOENT;
+		kfree(wq->name);
+		wq->name = NULL;
+	}
+
+	if ( wq->name ) {
+		/* Block all but "shutdown" signals while waiting */
+		sigset_t sigmask;
+
+		siginitsetinv(&sigmask, SHUTDOWN_SIGS);
+		sigprocmask(SIG_BLOCK, &sigmask, &sigmask);
+
+		interruptible_sleep_on(&wq->queue);
+
+		sigprocmask(SIG_SETMASK, &sigmask, NULL);
+	} else {
+		DPRINTK(("autofs_wait: skipped sleeping\n"));
+	}
+
+	status = wq->status;
+
+	if ( ! --wq->wait_ctr )	/* Are we the last process to need status? */
+		kfree(wq);
+
+	return status;
+}
+
+
+int autofs_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int status)
+{
+	struct autofs_wait_queue *wq, **wql;
+
+	for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) {
+		if ( wq->wait_queue_token == wait_queue_token )
+			break;
+	}
+	if ( !wq )
+		return -EINVAL;
+
+	*wql = wq->next;	/* Unlink from chain */
+	kfree(wq->name);
+	wq->name = NULL;	/* Do not wait on this queue */
+
+	wq->status = status;
+
+	if ( ! --wq->wait_ctr )	/* Is anyone still waiting for this guy? */
+		kfree(wq);
+	else
+		wake_up(&wq->queue);
+
+	return 0;
+}
+