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authorGlenn Elliott <gelliott@cs.unc.edu>2012-03-04 19:47:13 -0500
committerGlenn Elliott <gelliott@cs.unc.edu>2012-03-04 19:47:13 -0500
commitc71c03bda1e86c9d5198c5d83f712e695c4f2a1e (patch)
treeecb166cb3e2b7e2adb3b5e292245fefd23381ac8 /fs/autofs/dirhash.c
parentea53c912f8a86a8567697115b6a0d8152beee5c8 (diff)
parent6a00f206debf8a5c8899055726ad127dbeeed098 (diff)
Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp
Conflicts: litmus/sched_cedf.c
Diffstat (limited to 'fs/autofs/dirhash.c')
-rw-r--r--fs/autofs/dirhash.c250
1 files changed, 0 insertions, 250 deletions
diff --git a/fs/autofs/dirhash.c b/fs/autofs/dirhash.c
deleted file mode 100644
index e947915109e5..000000000000
--- a/fs/autofs/dirhash.c
+++ /dev/null
@@ -1,250 +0,0 @@
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 unsigned long timeout = sbi->exp_timeout;
43
44 while (1) {
45 struct path path;
46 int umount_ok;
47
48 if ( list_empty(&dh->expiry_head) || sbi->catatonic )
49 return NULL; /* No entries */
50 /* We keep the list sorted by last_usage and want old stuff */
51 ent = list_entry(dh->expiry_head.next, struct autofs_dir_ent, exp);
52 if (jiffies - ent->last_usage < timeout)
53 break;
54 /* Move to end of list in case expiry isn't desirable */
55 autofs_update_usage(dh, ent);
56
57 /* Check to see that entry is expirable */
58 if ( ent->ino < AUTOFS_FIRST_DIR_INO )
59 return ent; /* Symlinks are always expirable */
60
61 /* Get the dentry for the autofs subdirectory */
62 path.dentry = ent->dentry;
63
64 if (!path.dentry) {
65 /* Should only happen in catatonic mode */
66 printk("autofs: dentry == NULL but inode range is directory, entry %s\n", ent->name);
67 autofs_delete_usage(ent);
68 continue;
69 }
70
71 if (!path.dentry->d_inode) {
72 dput(path.dentry);
73 printk("autofs: negative dentry on expiry queue: %s\n",
74 ent->name);
75 autofs_delete_usage(ent);
76 continue;
77 }
78
79 /* Make sure entry is mounted and unused; note that dentry will
80 point to the mounted-on-top root. */
81 if (!S_ISDIR(path.dentry->d_inode->i_mode) ||
82 !d_mountpoint(path.dentry)) {
83 DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));
84 continue;
85 }
86 path.mnt = mnt;
87 path_get(&path);
88 if (!follow_down(&path)) {
89 path_put(&path);
90 DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));
91 continue;
92 }
93 while (d_mountpoint(path.dentry) && follow_down(&path))
94 ;
95 umount_ok = may_umount(path.mnt);
96 path_put(&path);
97
98 if (umount_ok) {
99 DPRINTK(("autofs: signaling expire on %s\n", ent->name));
100 return ent; /* Expirable! */
101 }
102 DPRINTK(("autofs: didn't expire due to may_umount: %s\n", ent->name));
103 }
104 return NULL; /* No expirable entries */
105}
106
107void autofs_initialize_hash(struct autofs_dirhash *dh) {
108 memset(&dh->h, 0, AUTOFS_HASH_SIZE*sizeof(struct autofs_dir_ent *));
109 INIT_LIST_HEAD(&dh->expiry_head);
110}
111
112struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *dh, struct qstr *name)
113{
114 struct autofs_dir_ent *dhn;
115
116 DPRINTK(("autofs_hash_lookup: hash = 0x%08x, name = ", name->hash));
117 autofs_say(name->name,name->len);
118
119 for ( dhn = dh->h[(unsigned) name->hash % AUTOFS_HASH_SIZE] ; dhn ; dhn = dhn->next ) {
120 if ( name->hash == dhn->hash &&
121 name->len == dhn->len &&
122 !memcmp(name->name, dhn->name, name->len) )
123 break;
124 }
125
126 return dhn;
127}
128
129void autofs_hash_insert(struct autofs_dirhash *dh, struct autofs_dir_ent *ent)
130{
131 struct autofs_dir_ent **dhnp;
132
133 DPRINTK(("autofs_hash_insert: hash = 0x%08x, name = ", ent->hash));
134 autofs_say(ent->name,ent->len);
135
136 autofs_init_usage(dh,ent);
137 if (ent->dentry)
138 dget(ent->dentry);
139
140 dhnp = &dh->h[(unsigned) ent->hash % AUTOFS_HASH_SIZE];
141 ent->next = *dhnp;
142 ent->back = dhnp;
143 *dhnp = ent;
144 if ( ent->next )
145 ent->next->back = &(ent->next);
146}
147
148void autofs_hash_delete(struct autofs_dir_ent *ent)
149{
150 *(ent->back) = ent->next;
151 if ( ent->next )
152 ent->next->back = ent->back;
153
154 autofs_delete_usage(ent);
155
156 if ( ent->dentry )
157 dput(ent->dentry);
158 kfree(ent->name);
159 kfree(ent);
160}
161
162/*
163 * Used by readdir(). We must validate "ptr", so we can't simply make it
164 * a pointer. Values below 0xffff are reserved; calling with any value
165 * <= 0x10000 will return the first entry found.
166 *
167 * "last" can be NULL or the value returned by the last search *if* we
168 * want the next sequential entry.
169 */
170struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *dh,
171 off_t *ptr, struct autofs_dir_ent *last)
172{
173 int bucket, ecount, i;
174 struct autofs_dir_ent *ent;
175
176 bucket = (*ptr >> 16) - 1;
177 ecount = *ptr & 0xffff;
178
179 if ( bucket < 0 ) {
180 bucket = ecount = 0;
181 }
182
183 DPRINTK(("autofs_hash_enum: bucket %d, entry %d\n", bucket, ecount));
184
185 ent = last ? last->next : NULL;
186
187 if ( ent ) {
188 ecount++;
189 } else {
190 while ( bucket < AUTOFS_HASH_SIZE ) {
191 ent = dh->h[bucket];
192 for ( i = ecount ; ent && i ; i-- )
193 ent = ent->next;
194
195 if (ent) {
196 ecount++; /* Point to *next* entry */
197 break;
198 }
199
200 bucket++; ecount = 0;
201 }
202 }
203
204#ifdef DEBUG
205 if ( !ent )
206 printk("autofs_hash_enum: nothing found\n");
207 else {
208 printk("autofs_hash_enum: found hash %08x, name", ent->hash);
209 autofs_say(ent->name,ent->len);
210 }
211#endif
212
213 *ptr = ((bucket+1) << 16) + ecount;
214 return ent;
215}
216
217/* Iterate over all the ents, and remove all dentry pointers. Used on
218 entering catatonic mode, in order to make the filesystem unmountable. */
219void autofs_hash_dputall(struct autofs_dirhash *dh)
220{
221 int i;
222 struct autofs_dir_ent *ent;
223
224 for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) {
225 for ( ent = dh->h[i] ; ent ; ent = ent->next ) {
226 if ( ent->dentry ) {
227 dput(ent->dentry);
228 ent->dentry = NULL;
229 }
230 }
231 }
232}
233
234/* Delete everything. This is used on filesystem destruction, so we
235 make no attempt to keep the pointers valid */
236void autofs_hash_nuke(struct autofs_sb_info *sbi)
237{
238 int i;
239 struct autofs_dir_ent *ent, *nent;
240
241 for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) {
242 for ( ent = sbi->dirhash.h[i] ; ent ; ent = nent ) {
243 nent = ent->next;
244 if ( ent->dentry )
245 dput(ent->dentry);
246 kfree(ent->name);
247 kfree(ent);
248 }
249 }
250}
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-13 16:26:04 -0400