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Commit | Line | Data |
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fea05a26 | 1 | /* Copyright (c) 2012 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> |
d5decd3b | 14 | #include <linux/export.h> |
1da177e4 LT |
15 | #include "aoe.h" |
16 | ||
17 | enum { | |
18 | //MINOR_STAT = 1, (moved to sysfs) | |
19 | MINOR_ERR = 2, | |
20 | MINOR_DISCOVER, | |
21 | MINOR_INTERFACES, | |
3ae1c24e | 22 | MINOR_REVALIDATE, |
262bf541 | 23 | MINOR_FLUSH, |
1da177e4 | 24 | MSGSZ = 2048, |
1da177e4 LT |
25 | NMSG = 100, /* message backlog to retain */ |
26 | }; | |
27 | ||
28 | struct aoe_chardev { | |
29 | ulong minor; | |
30 | char name[32]; | |
31 | }; | |
32 | ||
33 | enum { EMFL_VALID = 1 }; | |
34 | ||
35 | struct ErrMsg { | |
36 | short flags; | |
37 | short len; | |
38 | char *msg; | |
39 | }; | |
40 | ||
2a48fc0a | 41 | static DEFINE_MUTEX(aoechr_mutex); |
1da177e4 LT |
42 | static struct ErrMsg emsgs[NMSG]; |
43 | static int emsgs_head_idx, emsgs_tail_idx; | |
24879a8e | 44 | static struct completion emsgs_comp; |
1da177e4 LT |
45 | static spinlock_t emsgs_lock; |
46 | static int nblocked_emsgs_readers; | |
deb36970 | 47 | static struct class *aoe_class; |
1da177e4 LT |
48 | static struct aoe_chardev chardevs[] = { |
49 | { MINOR_ERR, "err" }, | |
50 | { MINOR_DISCOVER, "discover" }, | |
51 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 52 | { MINOR_REVALIDATE, "revalidate" }, |
262bf541 | 53 | { MINOR_FLUSH, "flush" }, |
1da177e4 LT |
54 | }; |
55 | ||
56 | static int | |
57 | discover(void) | |
58 | { | |
59 | aoecmd_cfg(0xffff, 0xff); | |
60 | return 0; | |
61 | } | |
62 | ||
63 | static int | |
64 | interfaces(const char __user *str, size_t size) | |
65 | { | |
66 | if (set_aoe_iflist(str, size)) { | |
a12c93f0 EC |
67 | printk(KERN_ERR |
68 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
69 | return -EINVAL; |
70 | } | |
71 | return 0; | |
72 | } | |
73 | ||
3ae1c24e EC |
74 | static int |
75 | revalidate(const char __user *str, size_t size) | |
76 | { | |
77 | int major, minor, n; | |
78 | ulong flags; | |
79 | struct aoedev *d; | |
68e0d42f | 80 | struct sk_buff *skb; |
3ae1c24e EC |
81 | char buf[16]; |
82 | ||
83 | if (size >= sizeof buf) | |
84 | return -EINVAL; | |
85 | buf[sizeof buf - 1] = '\0'; | |
86 | if (copy_from_user(buf, str, size)) | |
87 | return -EFAULT; | |
88 | ||
3ae1c24e EC |
89 | n = sscanf(buf, "e%d.%d", &major, &minor); |
90 | if (n != 2) { | |
896831f5 | 91 | pr_err("aoe: invalid device specification %s\n", buf); |
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 | 98 | aoecmd_cleanslate(d); |
25f4d75e | 99 | aoecmd_cfg(major, minor); |
68e0d42f EC |
100 | loop: |
101 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 102 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
103 | /* try again if we are able to sleep a bit, |
104 | * otherwise give up this revalidation | |
105 | */ | |
25f4d75e | 106 | if (!skb && !msleep_interruptible(250)) { |
68e0d42f EC |
107 | spin_lock_irqsave(&d->lock, flags); |
108 | goto loop; | |
109 | } | |
69cf2d85 | 110 | aoedev_put(d); |
e9bb8fb0 DM |
111 | if (skb) { |
112 | struct sk_buff_head queue; | |
113 | __skb_queue_head_init(&queue); | |
114 | __skb_queue_tail(&queue, skb); | |
115 | aoenet_xmit(&queue); | |
116 | } | |
3ae1c24e EC |
117 | return 0; |
118 | } | |
119 | ||
1da177e4 LT |
120 | void |
121 | aoechr_error(char *msg) | |
122 | { | |
123 | struct ErrMsg *em; | |
124 | char *mp; | |
125 | ulong flags, n; | |
126 | ||
127 | n = strlen(msg); | |
128 | ||
129 | spin_lock_irqsave(&emsgs_lock, flags); | |
130 | ||
131 | em = emsgs + emsgs_tail_idx; | |
132 | if ((em->flags & EMFL_VALID)) { | |
133 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
134 | return; | |
135 | } | |
136 | ||
137 | mp = kmalloc(n, GFP_ATOMIC); | |
138 | if (mp == NULL) { | |
a12c93f0 | 139 | printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n); |
1da177e4 LT |
140 | goto bail; |
141 | } | |
142 | ||
143 | memcpy(mp, msg, n); | |
144 | em->msg = mp; | |
145 | em->flags |= EMFL_VALID; | |
146 | em->len = n; | |
147 | ||
148 | emsgs_tail_idx++; | |
149 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
150 | ||
151 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
152 | ||
153 | if (nblocked_emsgs_readers) | |
24879a8e | 154 | complete(&emsgs_comp); |
1da177e4 LT |
155 | } |
156 | ||
157 | static ssize_t | |
158 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
159 | { | |
160 | int ret = -EINVAL; | |
161 | ||
162 | switch ((unsigned long) filp->private_data) { | |
163 | default: | |
a12c93f0 | 164 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
165 | break; |
166 | case MINOR_DISCOVER: | |
167 | ret = discover(); | |
168 | break; | |
169 | case MINOR_INTERFACES: | |
170 | ret = interfaces(buf, cnt); | |
171 | break; | |
3ae1c24e EC |
172 | case MINOR_REVALIDATE: |
173 | ret = revalidate(buf, cnt); | |
262bf541 EC |
174 | break; |
175 | case MINOR_FLUSH: | |
176 | ret = aoedev_flush(buf, cnt); | |
b21faa25 | 177 | break; |
1da177e4 LT |
178 | } |
179 | if (ret == 0) | |
180 | ret = cnt; | |
181 | return ret; | |
182 | } | |
183 | ||
184 | static int | |
185 | aoechr_open(struct inode *inode, struct file *filp) | |
186 | { | |
187 | int n, i; | |
188 | ||
2a48fc0a | 189 | mutex_lock(&aoechr_mutex); |
2017b376 | 190 | n = iminor(inode); |
1da177e4 LT |
191 | filp->private_data = (void *) (unsigned long) n; |
192 | ||
193 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
579174a5 | 194 | if (chardevs[i].minor == n) { |
2a48fc0a | 195 | mutex_unlock(&aoechr_mutex); |
1da177e4 | 196 | return 0; |
579174a5 | 197 | } |
2a48fc0a | 198 | mutex_unlock(&aoechr_mutex); |
1da177e4 LT |
199 | return -EINVAL; |
200 | } | |
201 | ||
202 | static int | |
203 | aoechr_rel(struct inode *inode, struct file *filp) | |
204 | { | |
205 | return 0; | |
206 | } | |
207 | ||
208 | static ssize_t | |
209 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
210 | { | |
211 | unsigned long n; | |
212 | char *mp; | |
213 | struct ErrMsg *em; | |
214 | ssize_t len; | |
215 | ulong flags; | |
216 | ||
217 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
218 | if (n != MINOR_ERR) |
219 | return -EFAULT; | |
220 | ||
221 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 222 | |
cf446f0d EC |
223 | for (;;) { |
224 | em = emsgs + emsgs_head_idx; | |
225 | if ((em->flags & EMFL_VALID) != 0) | |
226 | break; | |
227 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 228 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
229 | return -EAGAIN; |
230 | } | |
231 | nblocked_emsgs_readers++; | |
232 | ||
233 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 234 | |
24879a8e | 235 | n = wait_for_completion_interruptible(&emsgs_comp); |
1da177e4 | 236 | |
cf446f0d | 237 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 238 | |
cf446f0d | 239 | nblocked_emsgs_readers--; |
1da177e4 | 240 | |
cf446f0d | 241 | if (n) { |
1da177e4 | 242 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 243 | return -ERESTARTSYS; |
1da177e4 | 244 | } |
cf446f0d EC |
245 | } |
246 | if (em->len > cnt) { | |
247 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
248 | return -EAGAIN; | |
249 | } | |
250 | mp = em->msg; | |
251 | len = em->len; | |
252 | em->msg = NULL; | |
253 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 254 | |
cf446f0d EC |
255 | emsgs_head_idx++; |
256 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 257 | |
cf446f0d | 258 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 259 | |
cf446f0d EC |
260 | n = copy_to_user(buf, mp, len); |
261 | kfree(mp); | |
262 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
263 | } |
264 | ||
2b8693c0 | 265 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
266 | .write = aoechr_write, |
267 | .read = aoechr_read, | |
268 | .open = aoechr_open, | |
269 | .release = aoechr_rel, | |
270 | .owner = THIS_MODULE, | |
6038f373 | 271 | .llseek = noop_llseek, |
1da177e4 LT |
272 | }; |
273 | ||
2c9ede55 | 274 | static char *aoe_devnode(struct device *dev, umode_t *mode) |
1ce8a0d3 KS |
275 | { |
276 | return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev)); | |
277 | } | |
278 | ||
1da177e4 LT |
279 | int __init |
280 | aoechr_init(void) | |
281 | { | |
282 | int n, i; | |
283 | ||
284 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
285 | if (n < 0) { | |
a12c93f0 | 286 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
287 | return n; |
288 | } | |
24879a8e | 289 | init_completion(&emsgs_comp); |
1da177e4 | 290 | spin_lock_init(&emsgs_lock); |
deb36970 | 291 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
292 | if (IS_ERR(aoe_class)) { |
293 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
294 | return PTR_ERR(aoe_class); | |
295 | } | |
e454cea2 | 296 | aoe_class->devnode = aoe_devnode; |
1ce8a0d3 | 297 | |
1da177e4 | 298 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) |
1ff9f542 GKH |
299 | device_create(aoe_class, NULL, |
300 | MKDEV(AOE_MAJOR, chardevs[i].minor), NULL, | |
301 | chardevs[i].name); | |
1da177e4 LT |
302 | |
303 | return 0; | |
304 | } | |
305 | ||
306 | void | |
307 | aoechr_exit(void) | |
308 | { | |
309 | int i; | |
310 | ||
311 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 | 312 | device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
deb36970 | 313 | class_destroy(aoe_class); |
1da177e4 LT |
314 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
315 | } | |
316 |