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Commit | Line | Data |
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52e112b3 | 1 | /* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */ |
1da177e4 LT |
2 | /* |
3 | * aoechr.c | |
4 | * AoE character device driver | |
5 | */ | |
6 | ||
7 | #include <linux/hdreg.h> | |
8 | #include <linux/blkdev.h> | |
24879a8e | 9 | #include <linux/completion.h> |
68e0d42f | 10 | #include <linux/delay.h> |
579174a5 | 11 | #include <linux/smp_lock.h> |
e9bb8fb0 | 12 | #include <linux/skbuff.h> |
1da177e4 LT |
13 | #include "aoe.h" |
14 | ||
15 | enum { | |
16 | //MINOR_STAT = 1, (moved to sysfs) | |
17 | MINOR_ERR = 2, | |
18 | MINOR_DISCOVER, | |
19 | MINOR_INTERFACES, | |
3ae1c24e | 20 | MINOR_REVALIDATE, |
262bf541 | 21 | MINOR_FLUSH, |
1da177e4 | 22 | MSGSZ = 2048, |
1da177e4 LT |
23 | NMSG = 100, /* message backlog to retain */ |
24 | }; | |
25 | ||
26 | struct aoe_chardev { | |
27 | ulong minor; | |
28 | char name[32]; | |
29 | }; | |
30 | ||
31 | enum { EMFL_VALID = 1 }; | |
32 | ||
33 | struct ErrMsg { | |
34 | short flags; | |
35 | short len; | |
36 | char *msg; | |
37 | }; | |
38 | ||
39 | static struct ErrMsg emsgs[NMSG]; | |
40 | static int emsgs_head_idx, emsgs_tail_idx; | |
24879a8e | 41 | static struct completion emsgs_comp; |
1da177e4 LT |
42 | static spinlock_t emsgs_lock; |
43 | static int nblocked_emsgs_readers; | |
deb36970 | 44 | static struct class *aoe_class; |
1da177e4 LT |
45 | static struct aoe_chardev chardevs[] = { |
46 | { MINOR_ERR, "err" }, | |
47 | { MINOR_DISCOVER, "discover" }, | |
48 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 49 | { MINOR_REVALIDATE, "revalidate" }, |
262bf541 | 50 | { MINOR_FLUSH, "flush" }, |
1da177e4 LT |
51 | }; |
52 | ||
53 | static int | |
54 | discover(void) | |
55 | { | |
56 | aoecmd_cfg(0xffff, 0xff); | |
57 | return 0; | |
58 | } | |
59 | ||
60 | static int | |
61 | interfaces(const char __user *str, size_t size) | |
62 | { | |
63 | if (set_aoe_iflist(str, size)) { | |
a12c93f0 EC |
64 | printk(KERN_ERR |
65 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
66 | return -EINVAL; |
67 | } | |
68 | return 0; | |
69 | } | |
70 | ||
3ae1c24e EC |
71 | static int |
72 | revalidate(const char __user *str, size_t size) | |
73 | { | |
74 | int major, minor, n; | |
75 | ulong flags; | |
76 | struct aoedev *d; | |
68e0d42f | 77 | struct sk_buff *skb; |
3ae1c24e EC |
78 | char buf[16]; |
79 | ||
80 | if (size >= sizeof buf) | |
81 | return -EINVAL; | |
82 | buf[sizeof buf - 1] = '\0'; | |
83 | if (copy_from_user(buf, str, size)) | |
84 | return -EFAULT; | |
85 | ||
86 | /* should be e%d.%d format */ | |
87 | n = sscanf(buf, "e%d.%d", &major, &minor); | |
88 | if (n != 2) { | |
a12c93f0 | 89 | printk(KERN_ERR "aoe: invalid device specification\n"); |
3ae1c24e EC |
90 | return -EINVAL; |
91 | } | |
92 | d = aoedev_by_aoeaddr(major, minor); | |
93 | if (!d) | |
94 | return -EINVAL; | |
3ae1c24e | 95 | spin_lock_irqsave(&d->lock, flags); |
68e0d42f EC |
96 | aoecmd_cleanslate(d); |
97 | loop: | |
98 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 99 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
100 | /* try again if we are able to sleep a bit, |
101 | * otherwise give up this revalidation | |
102 | */ | |
103 | if (!skb && !msleep_interruptible(200)) { | |
104 | spin_lock_irqsave(&d->lock, flags); | |
105 | goto loop; | |
106 | } | |
e9bb8fb0 DM |
107 | if (skb) { |
108 | struct sk_buff_head queue; | |
109 | __skb_queue_head_init(&queue); | |
110 | __skb_queue_tail(&queue, skb); | |
111 | aoenet_xmit(&queue); | |
112 | } | |
3ae1c24e | 113 | aoecmd_cfg(major, minor); |
3ae1c24e EC |
114 | return 0; |
115 | } | |
116 | ||
1da177e4 LT |
117 | void |
118 | aoechr_error(char *msg) | |
119 | { | |
120 | struct ErrMsg *em; | |
121 | char *mp; | |
122 | ulong flags, n; | |
123 | ||
124 | n = strlen(msg); | |
125 | ||
126 | spin_lock_irqsave(&emsgs_lock, flags); | |
127 | ||
128 | em = emsgs + emsgs_tail_idx; | |
129 | if ((em->flags & EMFL_VALID)) { | |
130 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
131 | return; | |
132 | } | |
133 | ||
134 | mp = kmalloc(n, GFP_ATOMIC); | |
135 | if (mp == NULL) { | |
a12c93f0 | 136 | printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n); |
1da177e4 LT |
137 | goto bail; |
138 | } | |
139 | ||
140 | memcpy(mp, msg, n); | |
141 | em->msg = mp; | |
142 | em->flags |= EMFL_VALID; | |
143 | em->len = n; | |
144 | ||
145 | emsgs_tail_idx++; | |
146 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
147 | ||
148 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
149 | ||
150 | if (nblocked_emsgs_readers) | |
24879a8e | 151 | complete(&emsgs_comp); |
1da177e4 LT |
152 | } |
153 | ||
154 | static ssize_t | |
155 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
156 | { | |
157 | int ret = -EINVAL; | |
158 | ||
159 | switch ((unsigned long) filp->private_data) { | |
160 | default: | |
a12c93f0 | 161 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
162 | break; |
163 | case MINOR_DISCOVER: | |
164 | ret = discover(); | |
165 | break; | |
166 | case MINOR_INTERFACES: | |
167 | ret = interfaces(buf, cnt); | |
168 | break; | |
3ae1c24e EC |
169 | case MINOR_REVALIDATE: |
170 | ret = revalidate(buf, cnt); | |
262bf541 EC |
171 | break; |
172 | case MINOR_FLUSH: | |
173 | ret = aoedev_flush(buf, cnt); | |
1da177e4 LT |
174 | } |
175 | if (ret == 0) | |
176 | ret = cnt; | |
177 | return ret; | |
178 | } | |
179 | ||
180 | static int | |
181 | aoechr_open(struct inode *inode, struct file *filp) | |
182 | { | |
183 | int n, i; | |
184 | ||
579174a5 | 185 | lock_kernel(); |
2017b376 | 186 | n = iminor(inode); |
1da177e4 LT |
187 | filp->private_data = (void *) (unsigned long) n; |
188 | ||
189 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
579174a5 JC |
190 | if (chardevs[i].minor == n) { |
191 | unlock_kernel(); | |
1da177e4 | 192 | return 0; |
579174a5 JC |
193 | } |
194 | unlock_kernel(); | |
1da177e4 LT |
195 | return -EINVAL; |
196 | } | |
197 | ||
198 | static int | |
199 | aoechr_rel(struct inode *inode, struct file *filp) | |
200 | { | |
201 | return 0; | |
202 | } | |
203 | ||
204 | static ssize_t | |
205 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
206 | { | |
207 | unsigned long n; | |
208 | char *mp; | |
209 | struct ErrMsg *em; | |
210 | ssize_t len; | |
211 | ulong flags; | |
212 | ||
213 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
214 | if (n != MINOR_ERR) |
215 | return -EFAULT; | |
216 | ||
217 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 218 | |
cf446f0d EC |
219 | for (;;) { |
220 | em = emsgs + emsgs_head_idx; | |
221 | if ((em->flags & EMFL_VALID) != 0) | |
222 | break; | |
223 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 224 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
225 | return -EAGAIN; |
226 | } | |
227 | nblocked_emsgs_readers++; | |
228 | ||
229 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 230 | |
24879a8e | 231 | n = wait_for_completion_interruptible(&emsgs_comp); |
1da177e4 | 232 | |
cf446f0d | 233 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 234 | |
cf446f0d | 235 | nblocked_emsgs_readers--; |
1da177e4 | 236 | |
cf446f0d | 237 | if (n) { |
1da177e4 | 238 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 239 | return -ERESTARTSYS; |
1da177e4 | 240 | } |
cf446f0d EC |
241 | } |
242 | if (em->len > cnt) { | |
243 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
244 | return -EAGAIN; | |
245 | } | |
246 | mp = em->msg; | |
247 | len = em->len; | |
248 | em->msg = NULL; | |
249 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 250 | |
cf446f0d EC |
251 | emsgs_head_idx++; |
252 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 253 | |
cf446f0d | 254 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 255 | |
cf446f0d EC |
256 | n = copy_to_user(buf, mp, len); |
257 | kfree(mp); | |
258 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
259 | } |
260 | ||
2b8693c0 | 261 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
262 | .write = aoechr_write, |
263 | .read = aoechr_read, | |
264 | .open = aoechr_open, | |
265 | .release = aoechr_rel, | |
266 | .owner = THIS_MODULE, | |
267 | }; | |
268 | ||
269 | int __init | |
270 | aoechr_init(void) | |
271 | { | |
272 | int n, i; | |
273 | ||
274 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
275 | if (n < 0) { | |
a12c93f0 | 276 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
277 | return n; |
278 | } | |
24879a8e | 279 | init_completion(&emsgs_comp); |
1da177e4 | 280 | spin_lock_init(&emsgs_lock); |
deb36970 | 281 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
282 | if (IS_ERR(aoe_class)) { |
283 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
284 | return PTR_ERR(aoe_class); | |
285 | } | |
286 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
f79f0605 GKH |
287 | device_create_drvdata(aoe_class, NULL, |
288 | MKDEV(AOE_MAJOR, chardevs[i].minor), | |
289 | NULL, chardevs[i].name); | |
1da177e4 LT |
290 | |
291 | return 0; | |
292 | } | |
293 | ||
294 | void | |
295 | aoechr_exit(void) | |
296 | { | |
297 | int i; | |
298 | ||
299 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 | 300 | device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
deb36970 | 301 | class_destroy(aoe_class); |
1da177e4 LT |
302 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
303 | } | |
304 |