Commit | Line | Data |
---|---|---|
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); |
662a8896 EC |
42 | |
43 | /* A ring buffer of error messages, to be read through | |
44 | * "/dev/etherd/err". When no messages are present, | |
45 | * readers will block waiting for messages to appear. | |
46 | */ | |
1da177e4 LT |
47 | static struct ErrMsg emsgs[NMSG]; |
48 | static int emsgs_head_idx, emsgs_tail_idx; | |
24879a8e | 49 | static struct completion emsgs_comp; |
1da177e4 LT |
50 | static spinlock_t emsgs_lock; |
51 | static int nblocked_emsgs_readers; | |
65d7a37d | 52 | |
1da177e4 LT |
53 | static struct aoe_chardev chardevs[] = { |
54 | { MINOR_ERR, "err" }, | |
55 | { MINOR_DISCOVER, "discover" }, | |
56 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 57 | { MINOR_REVALIDATE, "revalidate" }, |
262bf541 | 58 | { MINOR_FLUSH, "flush" }, |
1da177e4 LT |
59 | }; |
60 | ||
65d7a37d IO |
61 | static char *aoe_devnode(const struct device *dev, umode_t *mode) |
62 | { | |
63 | return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev)); | |
64 | } | |
65 | ||
66 | static const struct class aoe_class = { | |
67 | .name = "aoe", | |
68 | .devnode = aoe_devnode, | |
69 | }; | |
70 | ||
1da177e4 LT |
71 | static int |
72 | discover(void) | |
73 | { | |
74 | aoecmd_cfg(0xffff, 0xff); | |
75 | return 0; | |
76 | } | |
77 | ||
78 | static int | |
79 | interfaces(const char __user *str, size_t size) | |
80 | { | |
81 | if (set_aoe_iflist(str, size)) { | |
a12c93f0 EC |
82 | printk(KERN_ERR |
83 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
84 | return -EINVAL; |
85 | } | |
86 | return 0; | |
87 | } | |
88 | ||
3ae1c24e EC |
89 | static int |
90 | revalidate(const char __user *str, size_t size) | |
91 | { | |
92 | int major, minor, n; | |
93 | ulong flags; | |
94 | struct aoedev *d; | |
68e0d42f | 95 | struct sk_buff *skb; |
3ae1c24e EC |
96 | char buf[16]; |
97 | ||
98 | if (size >= sizeof buf) | |
99 | return -EINVAL; | |
100 | buf[sizeof buf - 1] = '\0'; | |
101 | if (copy_from_user(buf, str, size)) | |
102 | return -EFAULT; | |
103 | ||
3ae1c24e EC |
104 | n = sscanf(buf, "e%d.%d", &major, &minor); |
105 | if (n != 2) { | |
896831f5 | 106 | pr_err("aoe: invalid device specification %s\n", buf); |
3ae1c24e EC |
107 | return -EINVAL; |
108 | } | |
0c966214 | 109 | d = aoedev_by_aoeaddr(major, minor, 0); |
3ae1c24e EC |
110 | if (!d) |
111 | return -EINVAL; | |
3ae1c24e | 112 | spin_lock_irqsave(&d->lock, flags); |
68e0d42f | 113 | aoecmd_cleanslate(d); |
25f4d75e | 114 | aoecmd_cfg(major, minor); |
68e0d42f EC |
115 | loop: |
116 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 117 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
118 | /* try again if we are able to sleep a bit, |
119 | * otherwise give up this revalidation | |
120 | */ | |
25f4d75e | 121 | if (!skb && !msleep_interruptible(250)) { |
68e0d42f EC |
122 | spin_lock_irqsave(&d->lock, flags); |
123 | goto loop; | |
124 | } | |
69cf2d85 | 125 | aoedev_put(d); |
e9bb8fb0 DM |
126 | if (skb) { |
127 | struct sk_buff_head queue; | |
128 | __skb_queue_head_init(&queue); | |
129 | __skb_queue_tail(&queue, skb); | |
130 | aoenet_xmit(&queue); | |
131 | } | |
3ae1c24e EC |
132 | return 0; |
133 | } | |
134 | ||
1da177e4 LT |
135 | void |
136 | aoechr_error(char *msg) | |
137 | { | |
138 | struct ErrMsg *em; | |
139 | char *mp; | |
140 | ulong flags, n; | |
141 | ||
142 | n = strlen(msg); | |
143 | ||
144 | spin_lock_irqsave(&emsgs_lock, flags); | |
145 | ||
146 | em = emsgs + emsgs_tail_idx; | |
147 | if ((em->flags & EMFL_VALID)) { | |
148 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
149 | return; | |
150 | } | |
151 | ||
60abc786 | 152 | mp = kmemdup(msg, n, GFP_ATOMIC); |
76cdb09b | 153 | if (!mp) |
1da177e4 | 154 | goto bail; |
1da177e4 | 155 | |
1da177e4 LT |
156 | em->msg = mp; |
157 | em->flags |= EMFL_VALID; | |
158 | em->len = n; | |
159 | ||
160 | emsgs_tail_idx++; | |
161 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
162 | ||
163 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
164 | ||
165 | if (nblocked_emsgs_readers) | |
24879a8e | 166 | complete(&emsgs_comp); |
1da177e4 LT |
167 | } |
168 | ||
169 | static ssize_t | |
170 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
171 | { | |
172 | int ret = -EINVAL; | |
173 | ||
174 | switch ((unsigned long) filp->private_data) { | |
175 | default: | |
a12c93f0 | 176 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
177 | break; |
178 | case MINOR_DISCOVER: | |
179 | ret = discover(); | |
180 | break; | |
181 | case MINOR_INTERFACES: | |
182 | ret = interfaces(buf, cnt); | |
183 | break; | |
3ae1c24e EC |
184 | case MINOR_REVALIDATE: |
185 | ret = revalidate(buf, cnt); | |
262bf541 EC |
186 | break; |
187 | case MINOR_FLUSH: | |
188 | ret = aoedev_flush(buf, cnt); | |
b21faa25 | 189 | break; |
1da177e4 LT |
190 | } |
191 | if (ret == 0) | |
192 | ret = cnt; | |
193 | return ret; | |
194 | } | |
195 | ||
196 | static int | |
197 | aoechr_open(struct inode *inode, struct file *filp) | |
198 | { | |
199 | int n, i; | |
200 | ||
2a48fc0a | 201 | mutex_lock(&aoechr_mutex); |
2017b376 | 202 | n = iminor(inode); |
1da177e4 LT |
203 | filp->private_data = (void *) (unsigned long) n; |
204 | ||
205 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
579174a5 | 206 | if (chardevs[i].minor == n) { |
2a48fc0a | 207 | mutex_unlock(&aoechr_mutex); |
1da177e4 | 208 | return 0; |
579174a5 | 209 | } |
2a48fc0a | 210 | mutex_unlock(&aoechr_mutex); |
1da177e4 LT |
211 | return -EINVAL; |
212 | } | |
213 | ||
214 | static int | |
215 | aoechr_rel(struct inode *inode, struct file *filp) | |
216 | { | |
217 | return 0; | |
218 | } | |
219 | ||
220 | static ssize_t | |
221 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
222 | { | |
223 | unsigned long n; | |
224 | char *mp; | |
225 | struct ErrMsg *em; | |
226 | ssize_t len; | |
227 | ulong flags; | |
228 | ||
229 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
230 | if (n != MINOR_ERR) |
231 | return -EFAULT; | |
232 | ||
233 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 234 | |
cf446f0d EC |
235 | for (;;) { |
236 | em = emsgs + emsgs_head_idx; | |
237 | if ((em->flags & EMFL_VALID) != 0) | |
238 | break; | |
239 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 240 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
241 | return -EAGAIN; |
242 | } | |
243 | nblocked_emsgs_readers++; | |
244 | ||
245 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 246 | |
24879a8e | 247 | n = wait_for_completion_interruptible(&emsgs_comp); |
1da177e4 | 248 | |
cf446f0d | 249 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 250 | |
cf446f0d | 251 | nblocked_emsgs_readers--; |
1da177e4 | 252 | |
cf446f0d | 253 | if (n) { |
1da177e4 | 254 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 255 | return -ERESTARTSYS; |
1da177e4 | 256 | } |
cf446f0d EC |
257 | } |
258 | if (em->len > cnt) { | |
259 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
260 | return -EAGAIN; | |
261 | } | |
262 | mp = em->msg; | |
263 | len = em->len; | |
264 | em->msg = NULL; | |
265 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 266 | |
cf446f0d EC |
267 | emsgs_head_idx++; |
268 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 269 | |
cf446f0d | 270 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 271 | |
cf446f0d EC |
272 | n = copy_to_user(buf, mp, len); |
273 | kfree(mp); | |
274 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
275 | } |
276 | ||
2b8693c0 | 277 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
278 | .write = aoechr_write, |
279 | .read = aoechr_read, | |
280 | .open = aoechr_open, | |
281 | .release = aoechr_rel, | |
282 | .owner = THIS_MODULE, | |
6038f373 | 283 | .llseek = noop_llseek, |
1da177e4 LT |
284 | }; |
285 | ||
286 | int __init | |
287 | aoechr_init(void) | |
288 | { | |
289 | int n, i; | |
290 | ||
291 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
a04b41cd | 292 | if (n < 0) { |
a12c93f0 | 293 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
294 | return n; |
295 | } | |
24879a8e | 296 | init_completion(&emsgs_comp); |
1da177e4 | 297 | spin_lock_init(&emsgs_lock); |
65d7a37d IO |
298 | n = class_register(&aoe_class); |
299 | if (n) { | |
1da177e4 | 300 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
65d7a37d | 301 | return n; |
1da177e4 | 302 | } |
1ce8a0d3 | 303 | |
1da177e4 | 304 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) |
65d7a37d | 305 | device_create(&aoe_class, NULL, |
1ff9f542 GKH |
306 | MKDEV(AOE_MAJOR, chardevs[i].minor), NULL, |
307 | chardevs[i].name); | |
1da177e4 LT |
308 | |
309 | return 0; | |
310 | } | |
311 | ||
312 | void | |
313 | aoechr_exit(void) | |
314 | { | |
315 | int i; | |
316 | ||
317 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
65d7a37d IO |
318 | device_destroy(&aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
319 | class_unregister(&aoe_class); | |
1da177e4 LT |
320 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
321 | } | |
322 |