55 int register_blkdev(unsigned int major, const char *name)
56 {
57 struct blk_major_name **n, *p;
58 int index, ret = 0;
59
60 mutex_lock(&block_subsys_lock);
61
62 /* temporary */
63 if (major == 0) {
64 for (index = ARRAY_SIZE(major_names)-1; index > 0; index–) {
65 if (major_names[index] == NULL)
66 break;
67 }
68
69 if (index == 0) {
70 printk("register_blkdev: failed to get major for %s/n",
71 name);
72 ret = -EBUSY;
73 goto out;
74 }
75 major = index;
76 ret = major;
77 }
78
79 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
80 if (p == NULL) {
81 ret = -ENOMEM;
82 goto out;
83 }
84
85 p->major = major;
86 strlcpy(p->name, name, sizeof(p->name));
87 p->next = NULL;
88 index = major_to_index(major);
89
90 for (n = &major_names[index]; *n; n = &(*n)->next) {
91 if ((*n)->major == major)
92 break;
93 }
94 if (!*n)
95 *n = p;
96 else
97 ret = -EBUSY;
98
99 if (ret < 0) {
100 printk("register_blkdev: cannot get major %d for %s/n",
101 major, name);
102 kfree(p);
103 }
104 out:
105 mutex_unlock(&block_subsys_lock);
106 return ret;
107 }
人，也总是很难发现自己的错误，
