[PATCH] aoe 9/12: add note about the need for deadlock-free sk_buff allocation
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / block / aoe / aoeblk.c
CommitLineData
1da177e4
LT
1/* Copyright (c) 2004 Coraid, Inc. See COPYING for GPL terms. */
2/*
3 * aoeblk.c
4 * block device routines
5 */
6
7#include <linux/hdreg.h>
8#include <linux/blkdev.h>
9#include <linux/fs.h>
10#include <linux/ioctl.h>
11#include <linux/genhd.h>
12#include <linux/netdevice.h>
13#include "aoe.h"
14
15static kmem_cache_t *buf_pool_cache;
16
17/* add attributes for our block devices in sysfs */
18static ssize_t aoedisk_show_state(struct gendisk * disk, char *page)
19{
20 struct aoedev *d = disk->private_data;
21
22 return snprintf(page, PAGE_SIZE,
23 "%s%s\n",
24 (d->flags & DEVFL_UP) ? "up" : "down",
25 (d->flags & DEVFL_CLOSEWAIT) ? ",closewait" : "");
26}
27static ssize_t aoedisk_show_mac(struct gendisk * disk, char *page)
28{
29 struct aoedev *d = disk->private_data;
30
31 return snprintf(page, PAGE_SIZE, "%012llx\n",
32 (unsigned long long)mac_addr(d->addr));
33}
34static ssize_t aoedisk_show_netif(struct gendisk * disk, char *page)
35{
36 struct aoedev *d = disk->private_data;
37
38 return snprintf(page, PAGE_SIZE, "%s\n", d->ifp->name);
39}
40
41static struct disk_attribute disk_attr_state = {
42 .attr = {.name = "state", .mode = S_IRUGO },
43 .show = aoedisk_show_state
44};
45static struct disk_attribute disk_attr_mac = {
46 .attr = {.name = "mac", .mode = S_IRUGO },
47 .show = aoedisk_show_mac
48};
49static struct disk_attribute disk_attr_netif = {
50 .attr = {.name = "netif", .mode = S_IRUGO },
51 .show = aoedisk_show_netif
52};
53
54static void
55aoedisk_add_sysfs(struct aoedev *d)
56{
57 sysfs_create_file(&d->gd->kobj, &disk_attr_state.attr);
58 sysfs_create_file(&d->gd->kobj, &disk_attr_mac.attr);
59 sysfs_create_file(&d->gd->kobj, &disk_attr_netif.attr);
60}
61void
62aoedisk_rm_sysfs(struct aoedev *d)
63{
64 sysfs_remove_link(&d->gd->kobj, "state");
65 sysfs_remove_link(&d->gd->kobj, "mac");
66 sysfs_remove_link(&d->gd->kobj, "netif");
67}
68
69static int
70aoeblk_open(struct inode *inode, struct file *filp)
71{
72 struct aoedev *d;
73 ulong flags;
74
75 d = inode->i_bdev->bd_disk->private_data;
76
77 spin_lock_irqsave(&d->lock, flags);
78 if (d->flags & DEVFL_UP) {
79 d->nopen++;
80 spin_unlock_irqrestore(&d->lock, flags);
81 return 0;
82 }
83 spin_unlock_irqrestore(&d->lock, flags);
84 return -ENODEV;
85}
86
87static int
88aoeblk_release(struct inode *inode, struct file *filp)
89{
90 struct aoedev *d;
91 ulong flags;
92
93 d = inode->i_bdev->bd_disk->private_data;
94
95 spin_lock_irqsave(&d->lock, flags);
96
97 if (--d->nopen == 0 && (d->flags & DEVFL_CLOSEWAIT)) {
98 d->flags &= ~DEVFL_CLOSEWAIT;
99 spin_unlock_irqrestore(&d->lock, flags);
100 aoecmd_cfg(d->aoemajor, d->aoeminor);
101 return 0;
102 }
103 spin_unlock_irqrestore(&d->lock, flags);
104
105 return 0;
106}
107
108static int
109aoeblk_make_request(request_queue_t *q, struct bio *bio)
110{
111 struct aoedev *d;
112 struct buf *buf;
113 struct sk_buff *sl;
114 ulong flags;
115
116 blk_queue_bounce(q, &bio);
117
118 d = bio->bi_bdev->bd_disk->private_data;
119 buf = mempool_alloc(d->bufpool, GFP_NOIO);
120 if (buf == NULL) {
121 printk(KERN_INFO "aoe: aoeblk_make_request: buf allocation "
122 "failure\n");
123 bio_endio(bio, bio->bi_size, -ENOMEM);
124 return 0;
125 }
126 memset(buf, 0, sizeof(*buf));
127 INIT_LIST_HEAD(&buf->bufs);
128 buf->bio = bio;
129 buf->resid = bio->bi_size;
130 buf->sector = bio->bi_sector;
131 buf->bv = buf->bio->bi_io_vec;
132 buf->bv_resid = buf->bv->bv_len;
133 buf->bufaddr = page_address(buf->bv->bv_page) + buf->bv->bv_offset;
134
135 spin_lock_irqsave(&d->lock, flags);
136
137 if ((d->flags & DEVFL_UP) == 0) {
138 printk(KERN_INFO "aoe: aoeblk_make_request: device %ld.%ld is not up\n",
139 d->aoemajor, d->aoeminor);
140 spin_unlock_irqrestore(&d->lock, flags);
141 mempool_free(buf, d->bufpool);
142 bio_endio(bio, bio->bi_size, -ENXIO);
143 return 0;
144 }
145
146 list_add_tail(&buf->bufs, &d->bufq);
147 aoecmd_work(d);
148
149 sl = d->skblist;
150 d->skblist = NULL;
151
152 spin_unlock_irqrestore(&d->lock, flags);
153
154 aoenet_xmit(sl);
155 return 0;
156}
157
158/* This ioctl implementation expects userland to have the device node
159 * permissions set so that only priviledged users can open an aoe
160 * block device directly.
161 */
162static int
163aoeblk_ioctl(struct inode *inode, struct file *filp, uint cmd, ulong arg)
164{
165 struct aoedev *d;
166
167 if (!arg)
168 return -EINVAL;
169
170 d = inode->i_bdev->bd_disk->private_data;
171 if ((d->flags & DEVFL_UP) == 0) {
172 printk(KERN_ERR "aoe: aoeblk_ioctl: disk not up\n");
173 return -ENODEV;
174 }
175
176 if (cmd == HDIO_GETGEO) {
177 d->geo.start = get_start_sect(inode->i_bdev);
178 if (!copy_to_user((void __user *) arg, &d->geo, sizeof d->geo))
179 return 0;
180 return -EFAULT;
181 }
182 printk(KERN_INFO "aoe: aoeblk_ioctl: unknown ioctl %d\n", cmd);
183 return -EINVAL;
184}
185
186static struct block_device_operations aoe_bdops = {
187 .open = aoeblk_open,
188 .release = aoeblk_release,
189 .ioctl = aoeblk_ioctl,
190 .owner = THIS_MODULE,
191};
192
193/* alloc_disk and add_disk can sleep */
194void
195aoeblk_gdalloc(void *vp)
196{
197 struct aoedev *d = vp;
198 struct gendisk *gd;
199 ulong flags;
200
201 gd = alloc_disk(AOE_PARTITIONS);
202 if (gd == NULL) {
203 printk(KERN_ERR "aoe: aoeblk_gdalloc: cannot allocate disk "
204 "structure for %ld.%ld\n", d->aoemajor, d->aoeminor);
205 spin_lock_irqsave(&d->lock, flags);
206 d->flags &= ~DEVFL_WORKON;
207 spin_unlock_irqrestore(&d->lock, flags);
208 return;
209 }
210
211 d->bufpool = mempool_create(MIN_BUFS,
212 mempool_alloc_slab, mempool_free_slab,
213 buf_pool_cache);
214 if (d->bufpool == NULL) {
215 printk(KERN_ERR "aoe: aoeblk_gdalloc: cannot allocate bufpool "
216 "for %ld.%ld\n", d->aoemajor, d->aoeminor);
217 put_disk(gd);
218 spin_lock_irqsave(&d->lock, flags);
219 d->flags &= ~DEVFL_WORKON;
220 spin_unlock_irqrestore(&d->lock, flags);
221 return;
222 }
223
224 spin_lock_irqsave(&d->lock, flags);
225 blk_queue_make_request(&d->blkq, aoeblk_make_request);
226 gd->major = AOE_MAJOR;
227 gd->first_minor = d->sysminor * AOE_PARTITIONS;
228 gd->fops = &aoe_bdops;
229 gd->private_data = d;
230 gd->capacity = d->ssize;
231 snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%ld",
232 d->aoemajor, d->aoeminor);
233
234 gd->queue = &d->blkq;
235 d->gd = gd;
236 d->flags &= ~DEVFL_WORKON;
237 d->flags |= DEVFL_UP;
238
239 spin_unlock_irqrestore(&d->lock, flags);
240
241 add_disk(gd);
242 aoedisk_add_sysfs(d);
243
244 printk(KERN_INFO "aoe: %012llx e%lu.%lu v%04x has %llu "
245 "sectors\n", (unsigned long long)mac_addr(d->addr),
246 d->aoemajor, d->aoeminor,
247 d->fw_ver, (long long)d->ssize);
248}
249
250void
251aoeblk_exit(void)
252{
253 kmem_cache_destroy(buf_pool_cache);
254}
255
256int __init
257aoeblk_init(void)
258{
259 buf_pool_cache = kmem_cache_create("aoe_bufs",
260 sizeof(struct buf),
261 0, 0, NULL, NULL);
262 if (buf_pool_cache == NULL)
263 return -ENOMEM;
264
265 return 0;
266}
267