Commit | Line | Data |
---|---|---|
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> |
5a0e3ad6 | 11 | #include <linux/slab.h> |
2a48fc0a | 12 | #include <linux/mutex.h> |
e9bb8fb0 | 13 | #include <linux/skbuff.h> |
1da177e4 LT |
14 | #include "aoe.h" |
15 | ||
16 | enum { | |
17 | //MINOR_STAT = 1, (moved to sysfs) | |
18 | MINOR_ERR = 2, | |
19 | MINOR_DISCOVER, | |
20 | MINOR_INTERFACES, | |
3ae1c24e | 21 | MINOR_REVALIDATE, |
262bf541 | 22 | MINOR_FLUSH, |
1da177e4 | 23 | MSGSZ = 2048, |
1da177e4 LT |
24 | NMSG = 100, /* message backlog to retain */ |
25 | }; | |
26 | ||
27 | struct aoe_chardev { | |
28 | ulong minor; | |
29 | char name[32]; | |
30 | }; | |
31 | ||
32 | enum { EMFL_VALID = 1 }; | |
33 | ||
34 | struct ErrMsg { | |
35 | short flags; | |
36 | short len; | |
37 | char *msg; | |
38 | }; | |
39 | ||
2a48fc0a | 40 | static DEFINE_MUTEX(aoechr_mutex); |
1da177e4 LT |
41 | static struct ErrMsg emsgs[NMSG]; |
42 | static int emsgs_head_idx, emsgs_tail_idx; | |
24879a8e | 43 | static struct completion emsgs_comp; |
1da177e4 LT |
44 | static spinlock_t emsgs_lock; |
45 | static int nblocked_emsgs_readers; | |
deb36970 | 46 | static struct class *aoe_class; |
1da177e4 LT |
47 | static struct aoe_chardev chardevs[] = { |
48 | { MINOR_ERR, "err" }, | |
49 | { MINOR_DISCOVER, "discover" }, | |
50 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 51 | { MINOR_REVALIDATE, "revalidate" }, |
262bf541 | 52 | { MINOR_FLUSH, "flush" }, |
1da177e4 LT |
53 | }; |
54 | ||
55 | static int | |
56 | discover(void) | |
57 | { | |
58 | aoecmd_cfg(0xffff, 0xff); | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static int | |
63 | interfaces(const char __user *str, size_t size) | |
64 | { | |
65 | if (set_aoe_iflist(str, size)) { | |
a12c93f0 EC |
66 | printk(KERN_ERR |
67 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
68 | return -EINVAL; |
69 | } | |
70 | return 0; | |
71 | } | |
72 | ||
3ae1c24e EC |
73 | static int |
74 | revalidate(const char __user *str, size_t size) | |
75 | { | |
76 | int major, minor, n; | |
77 | ulong flags; | |
78 | struct aoedev *d; | |
68e0d42f | 79 | struct sk_buff *skb; |
3ae1c24e EC |
80 | char buf[16]; |
81 | ||
82 | if (size >= sizeof buf) | |
83 | return -EINVAL; | |
84 | buf[sizeof buf - 1] = '\0'; | |
85 | if (copy_from_user(buf, str, size)) | |
86 | return -EFAULT; | |
87 | ||
88 | /* should be e%d.%d format */ | |
89 | n = sscanf(buf, "e%d.%d", &major, &minor); | |
90 | if (n != 2) { | |
a12c93f0 | 91 | printk(KERN_ERR "aoe: invalid device specification\n"); |
3ae1c24e EC |
92 | return -EINVAL; |
93 | } | |
94 | d = aoedev_by_aoeaddr(major, minor); | |
95 | if (!d) | |
96 | return -EINVAL; | |
3ae1c24e | 97 | spin_lock_irqsave(&d->lock, flags); |
68e0d42f EC |
98 | aoecmd_cleanslate(d); |
99 | loop: | |
100 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 101 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
102 | /* try again if we are able to sleep a bit, |
103 | * otherwise give up this revalidation | |
104 | */ | |
105 | if (!skb && !msleep_interruptible(200)) { | |
106 | spin_lock_irqsave(&d->lock, flags); | |
107 | goto loop; | |
108 | } | |
e9bb8fb0 DM |
109 | if (skb) { |
110 | struct sk_buff_head queue; | |
111 | __skb_queue_head_init(&queue); | |
112 | __skb_queue_tail(&queue, skb); | |
113 | aoenet_xmit(&queue); | |
114 | } | |
3ae1c24e | 115 | aoecmd_cfg(major, minor); |
3ae1c24e EC |
116 | return 0; |
117 | } | |
118 | ||
1da177e4 LT |
119 | void |
120 | aoechr_error(char *msg) | |
121 | { | |
122 | struct ErrMsg *em; | |
123 | char *mp; | |
124 | ulong flags, n; | |
125 | ||
126 | n = strlen(msg); | |
127 | ||
128 | spin_lock_irqsave(&emsgs_lock, flags); | |
129 | ||
130 | em = emsgs + emsgs_tail_idx; | |
131 | if ((em->flags & EMFL_VALID)) { | |
132 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
133 | return; | |
134 | } | |
135 | ||
136 | mp = kmalloc(n, GFP_ATOMIC); | |
137 | if (mp == NULL) { | |
a12c93f0 | 138 | printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n); |
1da177e4 LT |
139 | goto bail; |
140 | } | |
141 | ||
142 | memcpy(mp, msg, n); | |
143 | em->msg = mp; | |
144 | em->flags |= EMFL_VALID; | |
145 | em->len = n; | |
146 | ||
147 | emsgs_tail_idx++; | |
148 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
149 | ||
150 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
151 | ||
152 | if (nblocked_emsgs_readers) | |
24879a8e | 153 | complete(&emsgs_comp); |
1da177e4 LT |
154 | } |
155 | ||
156 | static ssize_t | |
157 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
158 | { | |
159 | int ret = -EINVAL; | |
160 | ||
161 | switch ((unsigned long) filp->private_data) { | |
162 | default: | |
a12c93f0 | 163 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
164 | break; |
165 | case MINOR_DISCOVER: | |
166 | ret = discover(); | |
167 | break; | |
168 | case MINOR_INTERFACES: | |
169 | ret = interfaces(buf, cnt); | |
170 | break; | |
3ae1c24e EC |
171 | case MINOR_REVALIDATE: |
172 | ret = revalidate(buf, cnt); | |
262bf541 EC |
173 | break; |
174 | case MINOR_FLUSH: | |
175 | ret = aoedev_flush(buf, cnt); | |
1da177e4 LT |
176 | } |
177 | if (ret == 0) | |
178 | ret = cnt; | |
179 | return ret; | |
180 | } | |
181 | ||
182 | static int | |
183 | aoechr_open(struct inode *inode, struct file *filp) | |
184 | { | |
185 | int n, i; | |
186 | ||
2a48fc0a | 187 | mutex_lock(&aoechr_mutex); |
2017b376 | 188 | n = iminor(inode); |
1da177e4 LT |
189 | filp->private_data = (void *) (unsigned long) n; |
190 | ||
191 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
579174a5 | 192 | if (chardevs[i].minor == n) { |
2a48fc0a | 193 | mutex_unlock(&aoechr_mutex); |
1da177e4 | 194 | return 0; |
579174a5 | 195 | } |
2a48fc0a | 196 | mutex_unlock(&aoechr_mutex); |
1da177e4 LT |
197 | return -EINVAL; |
198 | } | |
199 | ||
200 | static int | |
201 | aoechr_rel(struct inode *inode, struct file *filp) | |
202 | { | |
203 | return 0; | |
204 | } | |
205 | ||
206 | static ssize_t | |
207 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
208 | { | |
209 | unsigned long n; | |
210 | char *mp; | |
211 | struct ErrMsg *em; | |
212 | ssize_t len; | |
213 | ulong flags; | |
214 | ||
215 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
216 | if (n != MINOR_ERR) |
217 | return -EFAULT; | |
218 | ||
219 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 220 | |
cf446f0d EC |
221 | for (;;) { |
222 | em = emsgs + emsgs_head_idx; | |
223 | if ((em->flags & EMFL_VALID) != 0) | |
224 | break; | |
225 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 226 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
227 | return -EAGAIN; |
228 | } | |
229 | nblocked_emsgs_readers++; | |
230 | ||
231 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 232 | |
24879a8e | 233 | n = wait_for_completion_interruptible(&emsgs_comp); |
1da177e4 | 234 | |
cf446f0d | 235 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 236 | |
cf446f0d | 237 | nblocked_emsgs_readers--; |
1da177e4 | 238 | |
cf446f0d | 239 | if (n) { |
1da177e4 | 240 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 241 | return -ERESTARTSYS; |
1da177e4 | 242 | } |
cf446f0d EC |
243 | } |
244 | if (em->len > cnt) { | |
245 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
246 | return -EAGAIN; | |
247 | } | |
248 | mp = em->msg; | |
249 | len = em->len; | |
250 | em->msg = NULL; | |
251 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 252 | |
cf446f0d EC |
253 | emsgs_head_idx++; |
254 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 255 | |
cf446f0d | 256 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 257 | |
cf446f0d EC |
258 | n = copy_to_user(buf, mp, len); |
259 | kfree(mp); | |
260 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
261 | } |
262 | ||
2b8693c0 | 263 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
264 | .write = aoechr_write, |
265 | .read = aoechr_read, | |
266 | .open = aoechr_open, | |
267 | .release = aoechr_rel, | |
268 | .owner = THIS_MODULE, | |
6038f373 | 269 | .llseek = noop_llseek, |
1da177e4 LT |
270 | }; |
271 | ||
e454cea2 | 272 | static char *aoe_devnode(struct device *dev, mode_t *mode) |
1ce8a0d3 KS |
273 | { |
274 | return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev)); | |
275 | } | |
276 | ||
1da177e4 LT |
277 | int __init |
278 | aoechr_init(void) | |
279 | { | |
280 | int n, i; | |
281 | ||
282 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
283 | if (n < 0) { | |
a12c93f0 | 284 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
285 | return n; |
286 | } | |
24879a8e | 287 | init_completion(&emsgs_comp); |
1da177e4 | 288 | spin_lock_init(&emsgs_lock); |
deb36970 | 289 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
290 | if (IS_ERR(aoe_class)) { |
291 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
292 | return PTR_ERR(aoe_class); | |
293 | } | |
e454cea2 | 294 | aoe_class->devnode = aoe_devnode; |
1ce8a0d3 | 295 | |
1da177e4 | 296 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) |
1ff9f542 GKH |
297 | device_create(aoe_class, NULL, |
298 | MKDEV(AOE_MAJOR, chardevs[i].minor), NULL, | |
299 | chardevs[i].name); | |
1da177e4 LT |
300 | |
301 | return 0; | |
302 | } | |
303 | ||
304 | void | |
305 | aoechr_exit(void) | |
306 | { | |
307 | int i; | |
308 | ||
309 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 | 310 | device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
deb36970 | 311 | class_destroy(aoe_class); |
1da177e4 LT |
312 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
313 | } | |
314 |