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>
9 #include <linux/delay.h>
13 //MINOR_STAT = 1, (moved to sysfs)
19 NMSG
= 100, /* message backlog to retain */
27 enum { EMFL_VALID
= 1 };
35 static struct ErrMsg emsgs
[NMSG
];
36 static int emsgs_head_idx
, emsgs_tail_idx
;
37 static struct semaphore emsgs_sema
;
38 static spinlock_t emsgs_lock
;
39 static int nblocked_emsgs_readers
;
40 static struct class *aoe_class
;
41 static struct aoe_chardev chardevs
[] = {
43 { MINOR_DISCOVER
, "discover" },
44 { MINOR_INTERFACES
, "interfaces" },
45 { MINOR_REVALIDATE
, "revalidate" },
51 aoecmd_cfg(0xffff, 0xff);
56 interfaces(const char __user
*str
, size_t size
)
58 if (set_aoe_iflist(str
, size
)) {
60 "aoe: could not set interface list: too many interfaces\n");
67 revalidate(const char __user
*str
, size_t size
)
75 if (size
>= sizeof buf
)
77 buf
[sizeof buf
- 1] = '\0';
78 if (copy_from_user(buf
, str
, size
))
81 /* should be e%d.%d format */
82 n
= sscanf(buf
, "e%d.%d", &major
, &minor
);
84 printk(KERN_ERR
"aoe: invalid device specification\n");
87 d
= aoedev_by_aoeaddr(major
, minor
);
90 spin_lock_irqsave(&d
->lock
, flags
);
93 skb
= aoecmd_ata_id(d
);
94 spin_unlock_irqrestore(&d
->lock
, flags
);
95 /* try again if we are able to sleep a bit,
96 * otherwise give up this revalidation
98 if (!skb
&& !msleep_interruptible(200)) {
99 spin_lock_irqsave(&d
->lock
, flags
);
103 aoecmd_cfg(major
, minor
);
108 aoechr_error(char *msg
)
116 spin_lock_irqsave(&emsgs_lock
, flags
);
118 em
= emsgs
+ emsgs_tail_idx
;
119 if ((em
->flags
& EMFL_VALID
)) {
120 bail
: spin_unlock_irqrestore(&emsgs_lock
, flags
);
124 mp
= kmalloc(n
, GFP_ATOMIC
);
126 printk(KERN_ERR
"aoe: allocation failure, len=%ld\n", n
);
132 em
->flags
|= EMFL_VALID
;
136 emsgs_tail_idx
%= ARRAY_SIZE(emsgs
);
138 spin_unlock_irqrestore(&emsgs_lock
, flags
);
140 if (nblocked_emsgs_readers
)
145 aoechr_write(struct file
*filp
, const char __user
*buf
, size_t cnt
, loff_t
*offp
)
149 switch ((unsigned long) filp
->private_data
) {
151 printk(KERN_INFO
"aoe: can't write to that file.\n");
156 case MINOR_INTERFACES
:
157 ret
= interfaces(buf
, cnt
);
159 case MINOR_REVALIDATE
:
160 ret
= revalidate(buf
, cnt
);
168 aoechr_open(struct inode
*inode
, struct file
*filp
)
173 filp
->private_data
= (void *) (unsigned long) n
;
175 for (i
= 0; i
< ARRAY_SIZE(chardevs
); ++i
)
176 if (chardevs
[i
].minor
== n
)
182 aoechr_rel(struct inode
*inode
, struct file
*filp
)
188 aoechr_read(struct file
*filp
, char __user
*buf
, size_t cnt
, loff_t
*off
)
196 n
= (unsigned long) filp
->private_data
;
200 spin_lock_irqsave(&emsgs_lock
, flags
);
203 em
= emsgs
+ emsgs_head_idx
;
204 if ((em
->flags
& EMFL_VALID
) != 0)
206 if (filp
->f_flags
& O_NDELAY
) {
207 spin_unlock_irqrestore(&emsgs_lock
, flags
);
210 nblocked_emsgs_readers
++;
212 spin_unlock_irqrestore(&emsgs_lock
, flags
);
214 n
= down_interruptible(&emsgs_sema
);
216 spin_lock_irqsave(&emsgs_lock
, flags
);
218 nblocked_emsgs_readers
--;
221 spin_unlock_irqrestore(&emsgs_lock
, flags
);
226 spin_unlock_irqrestore(&emsgs_lock
, flags
);
232 em
->flags
&= ~EMFL_VALID
;
235 emsgs_head_idx
%= ARRAY_SIZE(emsgs
);
237 spin_unlock_irqrestore(&emsgs_lock
, flags
);
239 n
= copy_to_user(buf
, mp
, len
);
241 return n
== 0 ? len
: -EFAULT
;
244 static const struct file_operations aoe_fops
= {
245 .write
= aoechr_write
,
248 .release
= aoechr_rel
,
249 .owner
= THIS_MODULE
,
257 n
= register_chrdev(AOE_MAJOR
, "aoechr", &aoe_fops
);
259 printk(KERN_ERR
"aoe: can't register char device\n");
262 sema_init(&emsgs_sema
, 0);
263 spin_lock_init(&emsgs_lock
);
264 aoe_class
= class_create(THIS_MODULE
, "aoe");
265 if (IS_ERR(aoe_class
)) {
266 unregister_chrdev(AOE_MAJOR
, "aoechr");
267 return PTR_ERR(aoe_class
);
269 for (i
= 0; i
< ARRAY_SIZE(chardevs
); ++i
)
270 device_create(aoe_class
, NULL
,
271 MKDEV(AOE_MAJOR
, chardevs
[i
].minor
), chardevs
[i
].name
);
281 for (i
= 0; i
< ARRAY_SIZE(chardevs
); ++i
)
282 device_destroy(aoe_class
, MKDEV(AOE_MAJOR
, chardevs
[i
].minor
));
283 class_destroy(aoe_class
);
284 unregister_chrdev(AOE_MAJOR
, "aoechr");