1 /* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */
4 * AoE character device driver
7 #include <linux/hdreg.h>
8 #include <linux/blkdev.h>
9 #include <linux/completion.h>
10 #include <linux/delay.h>
11 #include <linux/slab.h>
12 #include <linux/mutex.h>
13 #include <linux/skbuff.h>
14 #include <linux/export.h>
18 //MINOR_STAT = 1, (moved to sysfs)
25 NMSG = 100, /* message backlog to retain */
33 enum { EMFL_VALID = 1 };
41 static DEFINE_MUTEX(aoechr_mutex);
42 static struct ErrMsg emsgs[NMSG];
43 static int emsgs_head_idx, emsgs_tail_idx;
44 static struct completion emsgs_comp;
45 static spinlock_t emsgs_lock;
46 static int nblocked_emsgs_readers;
47 static struct class *aoe_class;
48 static struct aoe_chardev chardevs[] = {
50 { MINOR_DISCOVER, "discover" },
51 { MINOR_INTERFACES, "interfaces" },
52 { MINOR_REVALIDATE, "revalidate" },
53 { MINOR_FLUSH, "flush" },
59 aoecmd_cfg(0xffff, 0xff);
64 interfaces(const char __user *str, size_t size)
66 if (set_aoe_iflist(str, size)) {
68 "aoe: could not set interface list: too many interfaces\n");
75 revalidate(const char __user *str, size_t size)
83 if (size >= sizeof buf)
85 buf[sizeof buf - 1] = '\0';
86 if (copy_from_user(buf, str, size))
89 n = sscanf(buf, "e%d.%d", &major, &minor);
91 pr_err("aoe: invalid device specification %s\n", buf);
94 d = aoedev_by_aoeaddr(major, minor);
97 spin_lock_irqsave(&d->lock, flags);
100 skb = aoecmd_ata_id(d);
101 spin_unlock_irqrestore(&d->lock, flags);
102 /* try again if we are able to sleep a bit,
103 * otherwise give up this revalidation
105 if (!skb && !msleep_interruptible(200)) {
106 spin_lock_irqsave(&d->lock, flags);
110 struct sk_buff_head queue;
111 __skb_queue_head_init(&queue);
112 __skb_queue_tail(&queue, skb);
115 aoecmd_cfg(major, minor);
120 aoechr_error(char *msg)
128 spin_lock_irqsave(&emsgs_lock, flags);
130 em = emsgs + emsgs_tail_idx;
131 if ((em->flags & EMFL_VALID)) {
132 bail: spin_unlock_irqrestore(&emsgs_lock, flags);
136 mp = kmalloc(n, GFP_ATOMIC);
138 printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n);
144 em->flags |= EMFL_VALID;
148 emsgs_tail_idx %= ARRAY_SIZE(emsgs);
150 spin_unlock_irqrestore(&emsgs_lock, flags);
152 if (nblocked_emsgs_readers)
153 complete(&emsgs_comp);
157 aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp)
161 switch ((unsigned long) filp->private_data) {
163 printk(KERN_INFO "aoe: can't write to that file.\n");
168 case MINOR_INTERFACES:
169 ret = interfaces(buf, cnt);
171 case MINOR_REVALIDATE:
172 ret = revalidate(buf, cnt);
175 ret = aoedev_flush(buf, cnt);
183 aoechr_open(struct inode *inode, struct file *filp)
187 mutex_lock(&aoechr_mutex);
189 filp->private_data = (void *) (unsigned long) n;
191 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
192 if (chardevs[i].minor == n) {
193 mutex_unlock(&aoechr_mutex);
196 mutex_unlock(&aoechr_mutex);
201 aoechr_rel(struct inode *inode, struct file *filp)
207 aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
215 n = (unsigned long) filp->private_data;
219 spin_lock_irqsave(&emsgs_lock, flags);
222 em = emsgs + emsgs_head_idx;
223 if ((em->flags & EMFL_VALID) != 0)
225 if (filp->f_flags & O_NDELAY) {
226 spin_unlock_irqrestore(&emsgs_lock, flags);
229 nblocked_emsgs_readers++;
231 spin_unlock_irqrestore(&emsgs_lock, flags);
233 n = wait_for_completion_interruptible(&emsgs_comp);
235 spin_lock_irqsave(&emsgs_lock, flags);
237 nblocked_emsgs_readers--;
240 spin_unlock_irqrestore(&emsgs_lock, flags);
245 spin_unlock_irqrestore(&emsgs_lock, flags);
251 em->flags &= ~EMFL_VALID;
254 emsgs_head_idx %= ARRAY_SIZE(emsgs);
256 spin_unlock_irqrestore(&emsgs_lock, flags);
258 n = copy_to_user(buf, mp, len);
260 return n == 0 ? len : -EFAULT;
263 static const struct file_operations aoe_fops = {
264 .write = aoechr_write,
267 .release = aoechr_rel,
268 .owner = THIS_MODULE,
269 .llseek = noop_llseek,
272 static char *aoe_devnode(struct device *dev, umode_t *mode)
274 return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev));
282 n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops);
284 printk(KERN_ERR "aoe: can't register char device\n");
287 init_completion(&emsgs_comp);
288 spin_lock_init(&emsgs_lock);
289 aoe_class = class_create(THIS_MODULE, "aoe");
290 if (IS_ERR(aoe_class)) {
291 unregister_chrdev(AOE_MAJOR, "aoechr");
292 return PTR_ERR(aoe_class);
294 aoe_class->devnode = aoe_devnode;
296 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
297 device_create(aoe_class, NULL,
298 MKDEV(AOE_MAJOR, chardevs[i].minor), NULL,
309 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
310 device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor));
311 class_destroy(aoe_class);
312 unregister_chrdev(AOE_MAJOR, "aoechr");