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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/autofs
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/autofs')
-rw-r--r--fs/autofs/Makefile7
-rw-r--r--fs/autofs/autofs_i.h164
-rw-r--r--fs/autofs/dirhash.c249
-rw-r--r--fs/autofs/init.c52
-rw-r--r--fs/autofs/inode.c250
-rw-r--r--fs/autofs/root.c564
-rw-r--r--fs/autofs/symlink.c25
-rw-r--r--fs/autofs/waitq.c206
8 files changed, 1517 insertions, 0 deletions
diff --git a/fs/autofs/Makefile b/fs/autofs/Makefile
new file mode 100644
index 000000000000..453a60f46d05
--- /dev/null
+++ b/fs/autofs/Makefile
@@ -0,0 +1,7 @@
1#
2# Makefile for the linux autofs-filesystem routines.
3#
4
5obj-$(CONFIG_AUTOFS_FS) += autofs.o
6
7autofs-objs := dirhash.o init.o inode.o root.o symlink.o waitq.o
diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
new file mode 100644
index 000000000000..6171431272dc
--- /dev/null
+++ b/fs/autofs/autofs_i.h
@@ -0,0 +1,164 @@
1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * linux/fs/autofs/autofs_i.h
4 *
5 * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13/* Internal header file for autofs */
14
15#include <linux/auto_fs.h>
16
17/* This is the range of ioctl() numbers we claim as ours */
18#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
19#define AUTOFS_IOC_COUNT 32
20
21#include <linux/kernel.h>
22#include <linux/slab.h>
23#include <linux/time.h>
24#include <linux/string.h>
25#include <linux/wait.h>
26#include <linux/dcache.h>
27#include <linux/namei.h>
28#include <linux/mount.h>
29#include <linux/sched.h>
30
31#include <asm/current.h>
32#include <asm/uaccess.h>
33
34#ifdef DEBUG
35#define DPRINTK(D) (printk D)
36#else
37#define DPRINTK(D) ((void)0)
38#endif
39
40#define AUTOFS_SUPER_MAGIC 0x0187
41
42/*
43 * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
44 * kernel will keep the negative response cached for up to the time given
45 * here, although the time can be shorter if the kernel throws the dcache
46 * entry away. This probably should be settable from user space.
47 */
48#define AUTOFS_NEGATIVE_TIMEOUT (60*HZ) /* 1 minute */
49
50/* Structures associated with the root directory hash table */
51
52#define AUTOFS_HASH_SIZE 67
53
54struct autofs_dir_ent {
55 int hash;
56 char *name;
57 int len;
58 ino_t ino;
59 struct dentry *dentry;
60 /* Linked list of entries */
61 struct autofs_dir_ent *next;
62 struct autofs_dir_ent **back;
63 /* The following entries are for the expiry system */
64 unsigned long last_usage;
65 struct list_head exp;
66};
67
68struct autofs_dirhash {
69 struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
70 struct list_head expiry_head;
71};
72
73struct autofs_wait_queue {
74 wait_queue_head_t queue;
75 struct autofs_wait_queue *next;
76 autofs_wqt_t wait_queue_token;
77 /* We use the following to see what we are waiting for */
78 int hash;
79 int len;
80 char *name;
81 /* This is for status reporting upon return */
82 int status;
83 int wait_ctr;
84};
85
86struct autofs_symlink {
87 char *data;
88 int len;
89 time_t mtime;
90};
91
92#define AUTOFS_MAX_SYMLINKS 256
93
94#define AUTOFS_ROOT_INO 1
95#define AUTOFS_FIRST_SYMLINK 2
96#define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS)
97
98#define AUTOFS_SYMLINK_BITMAP_LEN \
99 ((AUTOFS_MAX_SYMLINKS+((sizeof(long)*1)-1))/(sizeof(long)*8))
100
101#define AUTOFS_SBI_MAGIC 0x6d4a556d
102
103struct autofs_sb_info {
104 u32 magic;
105 struct file *pipe;
106 pid_t oz_pgrp;
107 int catatonic;
108 unsigned long exp_timeout;
109 ino_t next_dir_ino;
110 struct autofs_wait_queue *queues; /* Wait queue pointer */
111 struct autofs_dirhash dirhash; /* Root directory hash */
112 struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS];
113 unsigned long symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN];
114};
115
116static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
117{
118 return (struct autofs_sb_info *)(sb->s_fs_info);
119}
120
121/* autofs_oz_mode(): do we see the man behind the curtain? (The
122 processes which do manipulations for us in user space sees the raw
123 filesystem without "magic".) */
124
125static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
126 return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
127}
128
129/* Hash operations */
130
131void autofs_initialize_hash(struct autofs_dirhash *);
132struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
133void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
134void autofs_hash_delete(struct autofs_dir_ent *);
135struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
136void autofs_hash_dputall(struct autofs_dirhash *);
137void autofs_hash_nuke(struct autofs_dirhash *);
138
139/* Expiration-handling functions */
140
141void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
142struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);
143
144/* Operations structures */
145
146extern struct inode_operations autofs_root_inode_operations;
147extern struct inode_operations autofs_symlink_inode_operations;
148extern struct file_operations autofs_root_operations;
149
150/* Initializing function */
151
152int autofs_fill_super(struct super_block *, void *, int);
153
154/* Queue management functions */
155
156int autofs_wait(struct autofs_sb_info *,struct qstr *);
157int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
158void autofs_catatonic_mode(struct autofs_sb_info *);
159
160#ifdef DEBUG
161void autofs_say(const char *name, int len);
162#else
163#define autofs_say(n,l) ((void)0)
164#endif
diff --git a/fs/autofs/dirhash.c b/fs/autofs/dirhash.c
new file mode 100644
index 000000000000..448143fd0796
--- /dev/null
+++ b/fs/autofs/dirhash.c
@@ -0,0 +1,249 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/dirhash.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include "autofs_i.h"
14
15/* Functions for maintenance of expiry queue */
16
17static void autofs_init_usage(struct autofs_dirhash *dh,
18 struct autofs_dir_ent *ent)
19{
20 list_add_tail(&ent->exp, &dh->expiry_head);
21 ent->last_usage = jiffies;
22}
23
24static void autofs_delete_usage(struct autofs_dir_ent *ent)
25{
26 list_del(&ent->exp);
27}
28
29void autofs_update_usage(struct autofs_dirhash *dh,
30 struct autofs_dir_ent *ent)
31{
32 autofs_delete_usage(ent); /* Unlink from current position */
33 autofs_init_usage(dh,ent); /* Relink at queue tail */
34}
35
36struct autofs_dir_ent *autofs_expire(struct super_block *sb,
37 struct autofs_sb_info *sbi,
38 struct vfsmount *mnt)
39{
40 struct autofs_dirhash *dh = &sbi->dirhash;
41 struct autofs_dir_ent *ent;
42 struct dentry *dentry;
43 unsigned long timeout = sbi->exp_timeout;
44
45 while (1) {
46 if ( list_empty(&dh->expiry_head) || sbi->catatonic )
47 return NULL; /* No entries */
48 /* We keep the list sorted by last_usage and want old stuff */
49 ent = list_entry(dh->expiry_head.next, struct autofs_dir_ent, exp);
50 if (jiffies - ent->last_usage < timeout)
51 break;
52 /* Move to end of list in case expiry isn't desirable */
53 autofs_update_usage(dh, ent);
54
55 /* Check to see that entry is expirable */
56 if ( ent->ino < AUTOFS_FIRST_DIR_INO )
57 return ent; /* Symlinks are always expirable */
58
59 /* Get the dentry for the autofs subdirectory */
60 dentry = ent->dentry;
61
62 if ( !dentry ) {
63 /* Should only happen in catatonic mode */
64 printk("autofs: dentry == NULL but inode range is directory, entry %s\n", ent->name);
65 autofs_delete_usage(ent);
66 continue;
67 }
68
69 if ( !dentry->d_inode ) {
70 dput(dentry);
71 printk("autofs: negative dentry on expiry queue: %s\n",
72 ent->name);
73 autofs_delete_usage(ent);
74 continue;
75 }
76
77 /* Make sure entry is mounted and unused; note that dentry will
78 point to the mounted-on-top root. */
79 if (!S_ISDIR(dentry->d_inode->i_mode)||!d_mountpoint(dentry)) {
80 DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));
81 continue;
82 }
83 mntget(mnt);
84 dget(dentry);
85 if (!follow_down(&mnt, &dentry)) {
86 dput(dentry);
87 mntput(mnt);
88 DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));
89 continue;
90 }
91 while (d_mountpoint(dentry) && follow_down(&mnt, &dentry))
92 ;
93 dput(dentry);
94
95 if ( may_umount(mnt) == 0 ) {
96 mntput(mnt);
97 DPRINTK(("autofs: signaling expire on %s\n", ent->name));
98 return ent; /* Expirable! */
99 }
100 DPRINTK(("autofs: didn't expire due to may_umount: %s\n", ent->name));
101 mntput(mnt);
102 }
103 return NULL; /* No expirable entries */
104}
105
106void autofs_initialize_hash(struct autofs_dirhash *dh) {
107 memset(&dh->h, 0, AUTOFS_HASH_SIZE*sizeof(struct autofs_dir_ent *));
108 INIT_LIST_HEAD(&dh->expiry_head);
109}
110
111struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *dh, struct qstr *name)
112{
113 struct autofs_dir_ent *dhn;
114
115 DPRINTK(("autofs_hash_lookup: hash = 0x%08x, name = ", name->hash));
116 autofs_say(name->name,name->len);
117
118 for ( dhn = dh->h[(unsigned) name->hash % AUTOFS_HASH_SIZE] ; dhn ; dhn = dhn->next ) {
119 if ( name->hash == dhn->hash &&
120 name->len == dhn->len &&
121 !memcmp(name->name, dhn->name, name->len) )
122 break;
123 }
124
125 return dhn;
126}
127
128void autofs_hash_insert(struct autofs_dirhash *dh, struct autofs_dir_ent *ent)
129{
130 struct autofs_dir_ent **dhnp;
131
132 DPRINTK(("autofs_hash_insert: hash = 0x%08x, name = ", ent->hash));
133 autofs_say(ent->name,ent->len);
134
135 autofs_init_usage(dh,ent);
136 if (ent->dentry)
137 dget(ent->dentry);
138
139 dhnp = &dh->h[(unsigned) ent->hash % AUTOFS_HASH_SIZE];
140 ent->next = *dhnp;
141 ent->back = dhnp;
142 *dhnp = ent;
143 if ( ent->next )
144 ent->next->back = &(ent->next);
145}
146
147void autofs_hash_delete(struct autofs_dir_ent *ent)
148{
149 *(ent->back) = ent->next;
150 if ( ent->next )
151 ent->next->back = ent->back;
152
153 autofs_delete_usage(ent);
154
155 if ( ent->dentry )
156 dput(ent->dentry);
157 kfree(ent->name);
158 kfree(ent);
159}
160
161/*
162 * Used by readdir(). We must validate "ptr", so we can't simply make it
163 * a pointer. Values below 0xffff are reserved; calling with any value
164 * <= 0x10000 will return the first entry found.
165 *
166 * "last" can be NULL or the value returned by the last search *if* we
167 * want the next sequential entry.
168 */
169struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *dh,
170 off_t *ptr, struct autofs_dir_ent *last)
171{
172 int bucket, ecount, i;
173 struct autofs_dir_ent *ent;
174
175 bucket = (*ptr >> 16) - 1;
176 ecount = *ptr & 0xffff;
177
178 if ( bucket < 0 ) {
179 bucket = ecount = 0;
180 }
181
182 DPRINTK(("autofs_hash_enum: bucket %d, entry %d\n", bucket, ecount));
183
184 ent = last ? last->next : NULL;
185
186 if ( ent ) {
187 ecount++;
188 } else {
189 while ( bucket < AUTOFS_HASH_SIZE ) {
190 ent = dh->h[bucket];
191 for ( i = ecount ; ent && i ; i-- )
192 ent = ent->next;
193
194 if (ent) {
195 ecount++; /* Point to *next* entry */
196 break;
197 }
198
199 bucket++; ecount = 0;
200 }
201 }
202
203#ifdef DEBUG
204 if ( !ent )
205 printk("autofs_hash_enum: nothing found\n");
206 else {
207 printk("autofs_hash_enum: found hash %08x, name", ent->hash);
208 autofs_say(ent->name,ent->len);
209 }
210#endif
211
212 *ptr = ((bucket+1) << 16) + ecount;
213 return ent;
214}
215
216/* Iterate over all the ents, and remove all dentry pointers. Used on
217 entering catatonic mode, in order to make the filesystem unmountable. */
218void autofs_hash_dputall(struct autofs_dirhash *dh)
219{
220 int i;
221 struct autofs_dir_ent *ent;
222
223 for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) {
224 for ( ent = dh->h[i] ; ent ; ent = ent->next ) {
225 if ( ent->dentry ) {
226 dput(ent->dentry);
227 ent->dentry = NULL;
228 }
229 }
230 }
231}
232
233/* Delete everything. This is used on filesystem destruction, so we
234 make no attempt to keep the pointers valid */
235void autofs_hash_nuke(struct autofs_dirhash *dh)
236{
237 int i;
238 struct autofs_dir_ent *ent, *nent;
239
240 for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) {
241 for ( ent = dh->h[i] ; ent ; ent = nent ) {
242 nent = ent->next;
243 if ( ent->dentry )
244 dput(ent->dentry);
245 kfree(ent->name);
246 kfree(ent);
247 }
248 }
249}
diff --git a/fs/autofs/init.c b/fs/autofs/init.c
new file mode 100644
index 000000000000..b977ece69f0c
--- /dev/null
+++ b/fs/autofs/init.c
@@ -0,0 +1,52 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/init.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include "autofs_i.h"
16
17static struct super_block *autofs_get_sb(struct file_system_type *fs_type,
18 int flags, const char *dev_name, void *data)
19{
20 return get_sb_nodev(fs_type, flags, data, autofs_fill_super);
21}
22
23static struct file_system_type autofs_fs_type = {
24 .owner = THIS_MODULE,
25 .name = "autofs",
26 .get_sb = autofs_get_sb,
27 .kill_sb = kill_anon_super,
28};
29
30static int __init init_autofs_fs(void)
31{
32 return register_filesystem(&autofs_fs_type);
33}
34
35static void __exit exit_autofs_fs(void)
36{
37 unregister_filesystem(&autofs_fs_type);
38}
39
40module_init(init_autofs_fs);
41module_exit(exit_autofs_fs);
42
43#ifdef DEBUG
44void autofs_say(const char *name, int len)
45{
46 printk("(%d: ", len);
47 while ( len-- )
48 printk("%c", *name++);
49 printk(")\n");
50}
51#endif
52MODULE_LICENSE("GPL");
diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
new file mode 100644
index 000000000000..4888c1fabbf7
--- /dev/null
+++ b/fs/autofs/inode.c
@@ -0,0 +1,250 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/inode.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/slab.h>
16#include <linux/file.h>
17#include <linux/parser.h>
18#include <linux/bitops.h>
19#include "autofs_i.h"
20#include <linux/module.h>
21
22static void autofs_put_super(struct super_block *sb)
23{
24 struct autofs_sb_info *sbi = autofs_sbi(sb);
25 unsigned int n;
26
27 if ( !sbi->catatonic )
28 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
29
30 autofs_hash_nuke(&sbi->dirhash);
31 for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
32 if ( test_bit(n, sbi->symlink_bitmap) )
33 kfree(sbi->symlink[n].data);
34 }
35
36 kfree(sb->s_fs_info);
37
38 DPRINTK(("autofs: shutting down\n"));
39}
40
41static void autofs_read_inode(struct inode *inode);
42
43static struct super_operations autofs_sops = {
44 .read_inode = autofs_read_inode,
45 .put_super = autofs_put_super,
46 .statfs = simple_statfs,
47};
48
49enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
50
51static match_table_t autofs_tokens = {
52 {Opt_fd, "fd=%u"},
53 {Opt_uid, "uid=%u"},
54 {Opt_gid, "gid=%u"},
55 {Opt_pgrp, "pgrp=%u"},
56 {Opt_minproto, "minproto=%u"},
57 {Opt_maxproto, "maxproto=%u"},
58 {Opt_err, NULL}
59};
60
61static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
62{
63 char *p;
64 substring_t args[MAX_OPT_ARGS];
65 int option;
66
67 *uid = current->uid;
68 *gid = current->gid;
69 *pgrp = process_group(current);
70
71 *minproto = *maxproto = AUTOFS_PROTO_VERSION;
72
73 *pipefd = -1;
74
75 if (!options)
76 return 1;
77
78 while ((p = strsep(&options, ",")) != NULL) {
79 int token;
80 if (!*p)
81 continue;
82
83 token = match_token(p, autofs_tokens, args);
84 switch (token) {
85 case Opt_fd:
86 if (match_int(&args[0], &option))
87 return 1;
88 *pipefd = option;
89 break;
90 case Opt_uid:
91 if (match_int(&args[0], &option))
92 return 1;
93 *uid = option;
94 break;
95 case Opt_gid:
96 if (match_int(&args[0], &option))
97 return 1;
98 *gid = option;
99 break;
100 case Opt_pgrp:
101 if (match_int(&args[0], &option))
102 return 1;
103 *pgrp = option;
104 break;
105 case Opt_minproto:
106 if (match_int(&args[0], &option))
107 return 1;
108 *minproto = option;
109 break;
110 case Opt_maxproto:
111 if (match_int(&args[0], &option))
112 return 1;
113 *maxproto = option;
114 break;
115 default:
116 return 1;
117 }
118 }
119 return (*pipefd < 0);
120}
121
122int autofs_fill_super(struct super_block *s, void *data, int silent)
123{
124 struct inode * root_inode;
125 struct dentry * root;
126 struct file * pipe;
127 int pipefd;
128 struct autofs_sb_info *sbi;
129 int minproto, maxproto;
130
131 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
132 if ( !sbi )
133 goto fail_unlock;
134 memset(sbi, 0, sizeof(*sbi));
135 DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
136
137 s->s_fs_info = sbi;
138 sbi->magic = AUTOFS_SBI_MAGIC;
139 sbi->catatonic = 0;
140 sbi->exp_timeout = 0;
141 sbi->oz_pgrp = process_group(current);
142 autofs_initialize_hash(&sbi->dirhash);
143 sbi->queues = NULL;
144 memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
145 sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
146 s->s_blocksize = 1024;
147 s->s_blocksize_bits = 10;
148 s->s_magic = AUTOFS_SUPER_MAGIC;
149 s->s_op = &autofs_sops;
150 s->s_time_gran = 1;
151
152 root_inode = iget(s, AUTOFS_ROOT_INO);
153 root = d_alloc_root(root_inode);
154 pipe = NULL;
155
156 if (!root)
157 goto fail_iput;
158
159 /* Can this call block? - WTF cares? s is locked. */
160 if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
161 printk("autofs: called with bogus options\n");
162 goto fail_dput;
163 }
164
165 /* Couldn't this be tested earlier? */
166 if ( minproto > AUTOFS_PROTO_VERSION ||
167 maxproto < AUTOFS_PROTO_VERSION ) {
168 printk("autofs: kernel does not match daemon version\n");
169 goto fail_dput;
170 }
171
172 DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
173 pipe = fget(pipefd);
174
175 if ( !pipe ) {
176 printk("autofs: could not open pipe file descriptor\n");
177 goto fail_dput;
178 }
179 if ( !pipe->f_op || !pipe->f_op->write )
180 goto fail_fput;
181 sbi->pipe = pipe;
182
183 /*
184 * Success! Install the root dentry now to indicate completion.
185 */
186 s->s_root = root;
187 return 0;
188
189fail_fput:
190 printk("autofs: pipe file descriptor does not contain proper ops\n");
191 fput(pipe);
192fail_dput:
193 dput(root);
194 goto fail_free;
195fail_iput:
196 printk("autofs: get root dentry failed\n");
197 iput(root_inode);
198fail_free:
199 kfree(sbi);
200fail_unlock:
201 return -EINVAL;
202}
203
204static void autofs_read_inode(struct inode *inode)
205{
206 ino_t ino = inode->i_ino;
207 unsigned int n;
208 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
209
210 /* Initialize to the default case (stub directory) */
211
212 inode->i_op = &simple_dir_inode_operations;
213 inode->i_fop = &simple_dir_operations;
214 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
215 inode->i_nlink = 2;
216 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
217 inode->i_blocks = 0;
218 inode->i_blksize = 1024;
219
220 if ( ino == AUTOFS_ROOT_INO ) {
221 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
222 inode->i_op = &autofs_root_inode_operations;
223 inode->i_fop = &autofs_root_operations;
224 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
225 return;
226 }
227
228 inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
229 inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
230
231 if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) {
232 /* Symlink inode - should be in symlink list */
233 struct autofs_symlink *sl;
234
235 n = ino - AUTOFS_FIRST_SYMLINK;
236 if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
237 printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
238 return;
239 }
240
241 inode->i_op = &autofs_symlink_inode_operations;
242 sl = &sbi->symlink[n];
243 inode->u.generic_ip = sl;
244 inode->i_mode = S_IFLNK | S_IRWXUGO;
245 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
246 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
247 inode->i_size = sl->len;
248 inode->i_nlink = 1;
249 }
250}
diff --git a/fs/autofs/root.c b/fs/autofs/root.c
new file mode 100644
index 000000000000..a1ab1c0ed215
--- /dev/null
+++ b/fs/autofs/root.c
@@ -0,0 +1,564 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/root.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include <linux/errno.h>
14#include <linux/stat.h>
15#include <linux/param.h>
16#include <linux/time.h>
17#include <linux/smp_lock.h>
18#include "autofs_i.h"
19
20static int autofs_root_readdir(struct file *,void *,filldir_t);
21static struct dentry *autofs_root_lookup(struct inode *,struct dentry *, struct nameidata *);
22static int autofs_root_symlink(struct inode *,struct dentry *,const char *);
23static int autofs_root_unlink(struct inode *,struct dentry *);
24static int autofs_root_rmdir(struct inode *,struct dentry *);
25static int autofs_root_mkdir(struct inode *,struct dentry *,int);
26static int autofs_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
27
28struct file_operations autofs_root_operations = {
29 .read = generic_read_dir,
30 .readdir = autofs_root_readdir,
31 .ioctl = autofs_root_ioctl,
32};
33
34struct inode_operations autofs_root_inode_operations = {
35 .lookup = autofs_root_lookup,
36 .unlink = autofs_root_unlink,
37 .symlink = autofs_root_symlink,
38 .mkdir = autofs_root_mkdir,
39 .rmdir = autofs_root_rmdir,
40};
41
42static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
43{
44 struct autofs_dir_ent *ent = NULL;
45 struct autofs_dirhash *dirhash;
46 struct autofs_sb_info *sbi;
47 struct inode * inode = filp->f_dentry->d_inode;
48 off_t onr, nr;
49
50 lock_kernel();
51
52 sbi = autofs_sbi(inode->i_sb);
53 dirhash = &sbi->dirhash;
54 nr = filp->f_pos;
55
56 switch(nr)
57 {
58 case 0:
59 if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
60 goto out;
61 filp->f_pos = ++nr;
62 /* fall through */
63 case 1:
64 if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
65 goto out;
66 filp->f_pos = ++nr;
67 /* fall through */
68 default:
69 while ( onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent) ) {
70 if ( !ent->dentry || d_mountpoint(ent->dentry) ) {
71 if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
72 goto out;
73 filp->f_pos = nr;
74 }
75 }
76 break;
77 }
78
79out:
80 unlock_kernel();
81 return 0;
82}
83
84static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
85{
86 struct inode * inode;
87 struct autofs_dir_ent *ent;
88 int status = 0;
89
90 if ( !(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) ) {
91 do {
92 if ( status && dentry->d_inode ) {
93 if ( status != -ENOENT )
94 printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
95 return 0; /* Try to get the kernel to invalidate this dentry */
96 }
97
98 /* Turn this into a real negative dentry? */
99 if (status == -ENOENT) {
100 dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
101 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
102 return 1;
103 } else if (status) {
104 /* Return a negative dentry, but leave it "pending" */
105 return 1;
106 }
107 status = autofs_wait(sbi, &dentry->d_name);
108 } while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) );
109 }
110
111 /* Abuse this field as a pointer to the directory entry, used to
112 find the expire list pointers */
113 dentry->d_time = (unsigned long) ent;
114
115 if (!dentry->d_inode) {
116 inode = iget(sb, ent->ino);
117 if (!inode) {
118 /* Failed, but leave pending for next time */
119 return 1;
120 }
121 dentry->d_inode = inode;
122 }
123
124 /* If this is a directory that isn't a mount point, bitch at the
125 daemon and fix it in user space */
126 if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) {
127 return !autofs_wait(sbi, &dentry->d_name);
128 }
129
130 /* We don't update the usages for the autofs daemon itself, this
131 is necessary for recursive autofs mounts */
132 if ( !autofs_oz_mode(sbi) ) {
133 autofs_update_usage(&sbi->dirhash,ent);
134 }
135
136 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
137 return 1;
138}
139
140
141/*
142 * Revalidate is called on every cache lookup. Some of those
143 * cache lookups may actually happen while the dentry is not
144 * yet completely filled in, and revalidate has to delay such
145 * lookups..
146 */
147static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
148{
149 struct inode * dir;
150 struct autofs_sb_info *sbi;
151 struct autofs_dir_ent *ent;
152 int res;
153
154 lock_kernel();
155 dir = dentry->d_parent->d_inode;
156 sbi = autofs_sbi(dir->i_sb);
157
158 /* Pending dentry */
159 if ( dentry->d_flags & DCACHE_AUTOFS_PENDING ) {
160 if (autofs_oz_mode(sbi))
161 res = 1;
162 else
163 res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
164 unlock_kernel();
165 return res;
166 }
167
168 /* Negative dentry.. invalidate if "old" */
169 if (!dentry->d_inode) {
170 unlock_kernel();
171 return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
172 }
173
174 /* Check for a non-mountpoint directory */
175 if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) {
176 if (autofs_oz_mode(sbi))
177 res = 1;
178 else
179 res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
180 unlock_kernel();
181 return res;
182 }
183
184 /* Update the usage list */
185 if ( !autofs_oz_mode(sbi) ) {
186 ent = (struct autofs_dir_ent *) dentry->d_time;
187 if ( ent )
188 autofs_update_usage(&sbi->dirhash,ent);
189 }
190 unlock_kernel();
191 return 1;
192}
193
194static struct dentry_operations autofs_dentry_operations = {
195 .d_revalidate = autofs_revalidate,
196};
197
198static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
199{
200 struct autofs_sb_info *sbi;
201 int oz_mode;
202
203 DPRINTK(("autofs_root_lookup: name = "));
204 lock_kernel();
205 autofs_say(dentry->d_name.name,dentry->d_name.len);
206
207 if (dentry->d_name.len > NAME_MAX) {
208 unlock_kernel();
209 return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
210 }
211
212 sbi = autofs_sbi(dir->i_sb);
213
214 oz_mode = autofs_oz_mode(sbi);
215 DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
216 current->pid, process_group(current), sbi->catatonic, oz_mode));
217
218 /*
219 * Mark the dentry incomplete, but add it. This is needed so
220 * that the VFS layer knows about the dentry, and we can count
221 * on catching any lookups through the revalidate.
222 *
223 * Let all the hard work be done by the revalidate function that
224 * needs to be able to do this anyway..
225 *
226 * We need to do this before we release the directory semaphore.
227 */
228 dentry->d_op = &autofs_dentry_operations;
229 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
230 d_add(dentry, NULL);
231
232 up(&dir->i_sem);
233 autofs_revalidate(dentry, nd);
234 down(&dir->i_sem);
235
236 /*
237 * If we are still pending, check if we had to handle
238 * a signal. If so we can force a restart..
239 */
240 if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
241 /* See if we were interrupted */
242 if (signal_pending(current)) {
243 sigset_t *sigset = &current->pending.signal;
244 if (sigismember (sigset, SIGKILL) ||
245 sigismember (sigset, SIGQUIT) ||
246 sigismember (sigset, SIGINT)) {
247 unlock_kernel();
248 return ERR_PTR(-ERESTARTNOINTR);
249 }
250 }
251 }
252 unlock_kernel();
253
254 /*
255 * If this dentry is unhashed, then we shouldn't honour this
256 * lookup even if the dentry is positive. Returning ENOENT here
257 * doesn't do the right thing for all system calls, but it should
258 * be OK for the operations we permit from an autofs.
259 */
260 if ( dentry->d_inode && d_unhashed(dentry) )
261 return ERR_PTR(-ENOENT);
262
263 return NULL;
264}
265
266static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
267{
268 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
269 struct autofs_dirhash *dh = &sbi->dirhash;
270 struct autofs_dir_ent *ent;
271 unsigned int n;
272 int slsize;
273 struct autofs_symlink *sl;
274
275 DPRINTK(("autofs_root_symlink: %s <- ", symname));
276 autofs_say(dentry->d_name.name,dentry->d_name.len);
277
278 lock_kernel();
279 if ( !autofs_oz_mode(sbi) ) {
280 unlock_kernel();
281 return -EACCES;
282 }
283
284 if ( autofs_hash_lookup(dh, &dentry->d_name) ) {
285 unlock_kernel();
286 return -EEXIST;
287 }
288
289 n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
290 if ( n >= AUTOFS_MAX_SYMLINKS ) {
291 unlock_kernel();
292 return -ENOSPC;
293 }
294
295 set_bit(n,sbi->symlink_bitmap);
296 sl = &sbi->symlink[n];
297 sl->len = strlen(symname);
298 sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
299 if ( !sl->data ) {
300 clear_bit(n,sbi->symlink_bitmap);
301 unlock_kernel();
302 return -ENOSPC;
303 }
304
305 ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
306 if ( !ent ) {
307 kfree(sl->data);
308 clear_bit(n,sbi->symlink_bitmap);
309 unlock_kernel();
310 return -ENOSPC;
311 }
312
313 ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
314 if ( !ent->name ) {
315 kfree(sl->data);
316 kfree(ent);
317 clear_bit(n,sbi->symlink_bitmap);
318 unlock_kernel();
319 return -ENOSPC;
320 }
321
322 memcpy(sl->data,symname,slsize);
323 sl->mtime = get_seconds();
324
325 ent->ino = AUTOFS_FIRST_SYMLINK + n;
326 ent->hash = dentry->d_name.hash;
327 memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
328 ent->dentry = NULL; /* We don't keep the dentry for symlinks */
329
330 autofs_hash_insert(dh,ent);
331 d_instantiate(dentry, iget(dir->i_sb,ent->ino));
332 unlock_kernel();
333 return 0;
334}
335
336/*
337 * NOTE!
338 *
339 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
340 * that the file no longer exists. However, doing that means that the
341 * VFS layer can turn the dentry into a negative dentry, which we
342 * obviously do not want (we're dropping the entry not because it
343 * doesn't exist, but because it has timed out).
344 *
345 * Also see autofs_root_rmdir()..
346 */
347static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
348{
349 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
350 struct autofs_dirhash *dh = &sbi->dirhash;
351 struct autofs_dir_ent *ent;
352 unsigned int n;
353
354 /* This allows root to remove symlinks */
355 lock_kernel();
356 if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) {
357 unlock_kernel();
358 return -EACCES;
359 }
360
361 ent = autofs_hash_lookup(dh, &dentry->d_name);
362 if ( !ent ) {
363 unlock_kernel();
364 return -ENOENT;
365 }
366
367 n = ent->ino - AUTOFS_FIRST_SYMLINK;
368 if ( n >= AUTOFS_MAX_SYMLINKS ) {
369 unlock_kernel();
370 return -EISDIR; /* It's a directory, dummy */
371 }
372 if ( !test_bit(n,sbi->symlink_bitmap) ) {
373 unlock_kernel();
374 return -EINVAL; /* Nonexistent symlink? Shouldn't happen */
375 }
376
377 dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
378 autofs_hash_delete(ent);
379 clear_bit(n,sbi->symlink_bitmap);
380 kfree(sbi->symlink[n].data);
381 d_drop(dentry);
382
383 unlock_kernel();
384 return 0;
385}
386
387static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
388{
389 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
390 struct autofs_dirhash *dh = &sbi->dirhash;
391 struct autofs_dir_ent *ent;
392
393 lock_kernel();
394 if ( !autofs_oz_mode(sbi) ) {
395 unlock_kernel();
396 return -EACCES;
397 }
398
399 ent = autofs_hash_lookup(dh, &dentry->d_name);
400 if ( !ent ) {
401 unlock_kernel();
402 return -ENOENT;
403 }
404
405 if ( (unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO ) {
406 unlock_kernel();
407 return -ENOTDIR; /* Not a directory */
408 }
409
410 if ( ent->dentry != dentry ) {
411 printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
412 }
413
414 dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
415 autofs_hash_delete(ent);
416 dir->i_nlink--;
417 d_drop(dentry);
418 unlock_kernel();
419
420 return 0;
421}
422
423static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
424{
425 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
426 struct autofs_dirhash *dh = &sbi->dirhash;
427 struct autofs_dir_ent *ent;
428 ino_t ino;
429
430 lock_kernel();
431 if ( !autofs_oz_mode(sbi) ) {
432 unlock_kernel();
433 return -EACCES;
434 }
435
436 ent = autofs_hash_lookup(dh, &dentry->d_name);
437 if ( ent ) {
438 unlock_kernel();
439 return -EEXIST;
440 }
441
442 if ( sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO ) {
443 printk("autofs: Out of inode numbers -- what the heck did you do??\n");
444 unlock_kernel();
445 return -ENOSPC;
446 }
447 ino = sbi->next_dir_ino++;
448
449 ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
450 if ( !ent ) {
451 unlock_kernel();
452 return -ENOSPC;
453 }
454
455 ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
456 if ( !ent->name ) {
457 kfree(ent);
458 unlock_kernel();
459 return -ENOSPC;
460 }
461
462 ent->hash = dentry->d_name.hash;
463 memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
464 ent->ino = ino;
465 ent->dentry = dentry;
466 autofs_hash_insert(dh,ent);
467
468 dir->i_nlink++;
469 d_instantiate(dentry, iget(dir->i_sb,ino));
470 unlock_kernel();
471
472 return 0;
473}
474
475/* Get/set timeout ioctl() operation */
476static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
477 unsigned long __user *p)
478{
479 unsigned long ntimeout;
480
481 if (get_user(ntimeout, p) ||
482 put_user(sbi->exp_timeout / HZ, p))
483 return -EFAULT;
484
485 if ( ntimeout > ULONG_MAX/HZ )
486 sbi->exp_timeout = 0;
487 else
488 sbi->exp_timeout = ntimeout * HZ;
489
490 return 0;
491}
492
493/* Return protocol version */
494static inline int autofs_get_protover(int __user *p)
495{
496 return put_user(AUTOFS_PROTO_VERSION, p);
497}
498
499/* Perform an expiry operation */
500static inline int autofs_expire_run(struct super_block *sb,
501 struct autofs_sb_info *sbi,
502 struct vfsmount *mnt,
503 struct autofs_packet_expire __user *pkt_p)
504{
505 struct autofs_dir_ent *ent;
506 struct autofs_packet_expire pkt;
507
508 memset(&pkt,0,sizeof pkt);
509
510 pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
511 pkt.hdr.type = autofs_ptype_expire;
512
513 if ( !sbi->exp_timeout ||
514 !(ent = autofs_expire(sb,sbi,mnt)) )
515 return -EAGAIN;
516
517 pkt.len = ent->len;
518 memcpy(pkt.name, ent->name, pkt.len);
519 pkt.name[pkt.len] = '\0';
520
521 if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) )
522 return -EFAULT;
523
524 return 0;
525}
526
527/*
528 * ioctl()'s on the root directory is the chief method for the daemon to
529 * generate kernel reactions
530 */
531static int autofs_root_ioctl(struct inode *inode, struct file *filp,
532 unsigned int cmd, unsigned long arg)
533{
534 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
535 void __user *argp = (void __user *)arg;
536
537 DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,process_group(current)));
538
539 if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
540 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
541 return -ENOTTY;
542
543 if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
544 return -EPERM;
545
546 switch(cmd) {
547 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
548 return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
549 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
550 return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
551 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
552 autofs_catatonic_mode(sbi);
553 return 0;
554 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
555 return autofs_get_protover(argp);
556 case AUTOFS_IOC_SETTIMEOUT:
557 return autofs_get_set_timeout(sbi, argp);
558 case AUTOFS_IOC_EXPIRE:
559 return autofs_expire_run(inode->i_sb, sbi, filp->f_vfsmnt,
560 argp);
561 default:
562 return -ENOSYS;
563 }
564}
diff --git a/fs/autofs/symlink.c b/fs/autofs/symlink.c
new file mode 100644
index 000000000000..f028396f1383
--- /dev/null
+++ b/fs/autofs/symlink.c
@@ -0,0 +1,25 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/symlink.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include "autofs_i.h"
14
15static int autofs_follow_link(struct dentry *dentry, struct nameidata *nd)
16{
17 char *s=((struct autofs_symlink *)dentry->d_inode->u.generic_ip)->data;
18 nd_set_link(nd, s);
19 return 0;
20}
21
22struct inode_operations autofs_symlink_inode_operations = {
23 .readlink = generic_readlink,
24 .follow_link = autofs_follow_link
25};
diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c
new file mode 100644
index 000000000000..1fcaa1568541
--- /dev/null
+++ b/fs/autofs/waitq.c
@@ -0,0 +1,206 @@
1/* -*- linux-c -*- --------------------------------------------------------- *
2 *
3 * linux/fs/autofs/waitq.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ------------------------------------------------------------------------- */
12
13#include <linux/slab.h>
14#include <linux/time.h>
15#include <linux/signal.h>
16#include <linux/file.h>
17#include "autofs_i.h"
18
19/* We make this a static variable rather than a part of the superblock; it
20 is better if we don't reassign numbers easily even across filesystems */
21static autofs_wqt_t autofs_next_wait_queue = 1;
22
23/* These are the signals we allow interrupting a pending mount */
24#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT))
25
26void autofs_catatonic_mode(struct autofs_sb_info *sbi)
27{
28 struct autofs_wait_queue *wq, *nwq;
29
30 DPRINTK(("autofs: entering catatonic mode\n"));
31
32 sbi->catatonic = 1;
33 wq = sbi->queues;
34 sbi->queues = NULL; /* Erase all wait queues */
35 while ( wq ) {
36 nwq = wq->next;
37 wq->status = -ENOENT; /* Magic is gone - report failure */
38 kfree(wq->name);
39 wq->name = NULL;
40 wake_up(&wq->queue);
41 wq = nwq;
42 }
43 fput(sbi->pipe); /* Close the pipe */
44 autofs_hash_dputall(&sbi->dirhash); /* Remove all dentry pointers */
45}
46
47static int autofs_write(struct file *file, const void *addr, int bytes)
48{
49 unsigned long sigpipe, flags;
50 mm_segment_t fs;
51 const char *data = (const char *)addr;
52 ssize_t wr = 0;
53
54 /** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/
55
56 sigpipe = sigismember(&current->pending.signal, SIGPIPE);
57
58 /* Save pointer to user space and point back to kernel space */
59 fs = get_fs();
60 set_fs(KERNEL_DS);
61
62 while (bytes &&
63 (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
64 data += wr;
65 bytes -= wr;
66 }
67
68 set_fs(fs);
69
70 /* Keep the currently executing process from receiving a
71 SIGPIPE unless it was already supposed to get one */
72 if (wr == -EPIPE && !sigpipe) {
73 spin_lock_irqsave(&current->sighand->siglock, flags);
74 sigdelset(&current->pending.signal, SIGPIPE);
75 recalc_sigpending();
76 spin_unlock_irqrestore(&current->sighand->siglock, flags);
77 }
78
79 return (bytes > 0);
80}
81
82static void autofs_notify_daemon(struct autofs_sb_info *sbi, struct autofs_wait_queue *wq)
83{
84 struct autofs_packet_missing pkt;
85
86 DPRINTK(("autofs_wait: wait id = 0x%08lx, name = ", wq->wait_queue_token));
87 autofs_say(wq->name,wq->len);
88
89 memset(&pkt,0,sizeof pkt); /* For security reasons */
90
91 pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
92 pkt.hdr.type = autofs_ptype_missing;
93 pkt.wait_queue_token = wq->wait_queue_token;
94 pkt.len = wq->len;
95 memcpy(pkt.name, wq->name, pkt.len);
96 pkt.name[pkt.len] = '\0';
97
98 if ( autofs_write(sbi->pipe,&pkt,sizeof(struct autofs_packet_missing)) )
99 autofs_catatonic_mode(sbi);
100}
101
102int autofs_wait(struct autofs_sb_info *sbi, struct qstr *name)
103{
104 struct autofs_wait_queue *wq;
105 int status;
106
107 /* In catatonic mode, we don't wait for nobody */
108 if ( sbi->catatonic )
109 return -ENOENT;
110
111 /* We shouldn't be able to get here, but just in case */
112 if ( name->len > NAME_MAX )
113 return -ENOENT;
114
115 for ( wq = sbi->queues ; wq ; wq = wq->next ) {
116 if ( wq->hash == name->hash &&
117 wq->len == name->len &&
118 wq->name && !memcmp(wq->name,name->name,name->len) )
119 break;
120 }
121
122 if ( !wq ) {
123 /* Create a new wait queue */
124 wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
125 if ( !wq )
126 return -ENOMEM;
127
128 wq->name = kmalloc(name->len,GFP_KERNEL);
129 if ( !wq->name ) {
130 kfree(wq);
131 return -ENOMEM;
132 }
133 wq->wait_queue_token = autofs_next_wait_queue++;
134 init_waitqueue_head(&wq->queue);
135 wq->hash = name->hash;
136 wq->len = name->len;
137 wq->status = -EINTR; /* Status return if interrupted */
138 memcpy(wq->name, name->name, name->len);
139 wq->next = sbi->queues;
140 sbi->queues = wq;
141
142 /* autofs_notify_daemon() may block */
143 wq->wait_ctr = 2;
144 autofs_notify_daemon(sbi,wq);
145 } else
146 wq->wait_ctr++;
147
148 /* wq->name is NULL if and only if the lock is already released */
149
150 if ( sbi->catatonic ) {
151 /* We might have slept, so check again for catatonic mode */
152 wq->status = -ENOENT;
153 if ( wq->name ) {
154 kfree(wq->name);
155 wq->name = NULL;
156 }
157 }
158
159 if ( wq->name ) {
160 /* Block all but "shutdown" signals while waiting */
161 sigset_t sigmask;
162
163 siginitsetinv(&sigmask, SHUTDOWN_SIGS);
164 sigprocmask(SIG_BLOCK, &sigmask, &sigmask);
165
166 interruptible_sleep_on(&wq->queue);
167
168 sigprocmask(SIG_SETMASK, &sigmask, NULL);
169 } else {
170 DPRINTK(("autofs_wait: skipped sleeping\n"));
171 }
172
173 status = wq->status;
174
175 if ( ! --wq->wait_ctr ) /* Are we the last process to need status? */
176 kfree(wq);
177
178 return status;
179}
180
181
182int autofs_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int status)
183{
184 struct autofs_wait_queue *wq, **wql;
185
186 for ( wql = &sbi->queues ; (wq = *wql) != 0 ; wql = &wq->next ) {
187 if ( wq->wait_queue_token == wait_queue_token )
188 break;
189 }
190 if ( !wq )
191 return -EINVAL;
192
193 *wql = wq->next; /* Unlink from chain */
194 kfree(wq->name);
195 wq->name = NULL; /* Do not wait on this queue */
196
197 wq->status = status;
198
199 if ( ! --wq->wait_ctr ) /* Is anyone still waiting for this guy? */
200 kfree(wq);
201 else
202 wake_up(&wq->queue);
203
204 return 0;
205}
206
generated by cgit v1.2.2 (git 2.25.0) at 2024-09-21 15:54:09 -0400