1 /* Copyright (c) 2006 Coraid, Inc. See COPYING for GPL terms. */
4 * AoE character device driver
7 #include <linux/hdreg.h>
8 #include <linux/blkdev.h>
12 //MINOR_STAT = 1, (moved to sysfs)
18 NMSG = 100, /* message backlog to retain */
26 enum { EMFL_VALID = 1 };
34 static struct ErrMsg emsgs[NMSG];
35 static int emsgs_head_idx, emsgs_tail_idx;
36 static struct semaphore emsgs_sema;
37 static spinlock_t emsgs_lock;
38 static int nblocked_emsgs_readers;
39 static struct class *aoe_class;
40 static struct aoe_chardev chardevs[] = {
42 { MINOR_DISCOVER, "discover" },
43 { MINOR_INTERFACES, "interfaces" },
44 { MINOR_REVALIDATE, "revalidate" },
50 aoecmd_cfg(0xffff, 0xff);
55 interfaces(const char __user *str, size_t size)
57 if (set_aoe_iflist(str, size)) {
59 "%s: could not set interface list: %s\n",
60 __FUNCTION__, "too many interfaces");
67 revalidate(const char __user *str, size_t size)
74 if (size >= sizeof buf)
76 buf[sizeof buf - 1] = '\0';
77 if (copy_from_user(buf, str, size))
80 /* should be e%d.%d format */
81 n = sscanf(buf, "e%d.%d", &major, &minor);
83 printk(KERN_ERR "aoe: %s: invalid device specification\n",
87 d = aoedev_by_aoeaddr(major, minor);
91 spin_lock_irqsave(&d->lock, flags);
92 d->flags |= DEVFL_PAUSE;
93 spin_unlock_irqrestore(&d->lock, flags);
94 aoecmd_cfg(major, minor);
100 aoechr_error(char *msg)
108 spin_lock_irqsave(&emsgs_lock, flags);
110 em = emsgs + emsgs_tail_idx;
111 if ((em->flags & EMFL_VALID)) {
112 bail: spin_unlock_irqrestore(&emsgs_lock, flags);
116 mp = kmalloc(n, GFP_ATOMIC);
118 printk(KERN_CRIT "aoe: aoechr_error: allocation failure, len=%ld\n", n);
124 em->flags |= EMFL_VALID;
128 emsgs_tail_idx %= ARRAY_SIZE(emsgs);
130 spin_unlock_irqrestore(&emsgs_lock, flags);
132 if (nblocked_emsgs_readers)
137 aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp)
141 switch ((unsigned long) filp->private_data) {
143 printk(KERN_INFO "aoe: aoechr_write: can't write to that file.\n");
148 case MINOR_INTERFACES:
149 ret = interfaces(buf, cnt);
151 case MINOR_REVALIDATE:
152 ret = revalidate(buf, cnt);
160 aoechr_open(struct inode *inode, struct file *filp)
165 filp->private_data = (void *) (unsigned long) n;
167 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
168 if (chardevs[i].minor == n)
174 aoechr_rel(struct inode *inode, struct file *filp)
180 aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
188 n = (unsigned long) filp->private_data;
191 spin_lock_irqsave(&emsgs_lock, flags);
193 em = emsgs + emsgs_head_idx;
194 if ((em->flags & EMFL_VALID) == 0) {
195 if (filp->f_flags & O_NDELAY) {
196 spin_unlock_irqrestore(&emsgs_lock, flags);
199 nblocked_emsgs_readers++;
201 spin_unlock_irqrestore(&emsgs_lock, flags);
203 n = down_interruptible(&emsgs_sema);
205 spin_lock_irqsave(&emsgs_lock, flags);
207 nblocked_emsgs_readers--;
210 spin_unlock_irqrestore(&emsgs_lock, flags);
216 spin_unlock_irqrestore(&emsgs_lock, flags);
222 em->flags &= ~EMFL_VALID;
225 emsgs_head_idx %= ARRAY_SIZE(emsgs);
227 spin_unlock_irqrestore(&emsgs_lock, flags);
229 n = copy_to_user(buf, mp, len);
231 return n == 0 ? len : -EFAULT;
237 static struct file_operations aoe_fops = {
238 .write = aoechr_write,
241 .release = aoechr_rel,
242 .owner = THIS_MODULE,
250 n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops);
252 printk(KERN_ERR "aoe: aoechr_init: can't register char device\n");
255 sema_init(&emsgs_sema, 0);
256 spin_lock_init(&emsgs_lock);
257 aoe_class = class_create(THIS_MODULE, "aoe");
258 if (IS_ERR(aoe_class)) {
259 unregister_chrdev(AOE_MAJOR, "aoechr");
260 return PTR_ERR(aoe_class);
262 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
263 class_device_create(aoe_class, NULL,
264 MKDEV(AOE_MAJOR, chardevs[i].minor),
265 NULL, chardevs[i].name);
275 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
276 class_device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor));
277 class_destroy(aoe_class);
278 unregister_chrdev(AOE_MAJOR, "aoechr");