diff options
Diffstat (limited to 'block')
-rw-r--r-- | block/genhd.c | 106 |
1 files changed, 86 insertions, 20 deletions
diff --git a/block/genhd.c b/block/genhd.c index f1ed83f3f083..db57546a709d 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -38,34 +38,100 @@ static inline int major_to_index(int major) return major % MAX_PROBE_HASH; } -#ifdef CONFIG_PROC_FS -/* get block device names in somewhat random order */ -int get_blkdev_list(char *p, int used) +struct blkdev_info { + int index; + struct blk_major_name *bd; +}; + +/* + * iterate over a list of blkdev_info structures. allows + * the major_names array to be iterated over from outside this file + * must be called with the block_subsys_sem held + */ +void *get_next_blkdev(void *dev) +{ + struct blkdev_info *info; + + if (dev == NULL) { + info = kmalloc(sizeof(*info), GFP_KERNEL); + if (!info) + goto out; + info->index=0; + info->bd = major_names[info->index]; + if (info->bd) + goto out; + } else { + info = dev; + } + + while (info->index < ARRAY_SIZE(major_names)) { + if (info->bd) + info->bd = info->bd->next; + if (info->bd) + goto out; + /* + * No devices on this chain, move to the next + */ + info->index++; + info->bd = (info->index < ARRAY_SIZE(major_names)) ? + major_names[info->index] : NULL; + if (info->bd) + goto out; + } + +out: + return info; +} + +void *acquire_blkdev_list(void) +{ + down(&block_subsys_sem); + return get_next_blkdev(NULL); +} + +void release_blkdev_list(void *dev) +{ + up(&block_subsys_sem); + kfree(dev); +} + + +/* + * Count the number of records in the blkdev_list. + * must be called with the block_subsys_sem held + */ +int count_blkdev_list(void) { struct blk_major_name *n; - int i, len; + int i, count; - len = snprintf(p, (PAGE_SIZE-used), "\nBlock devices:\n"); + count = 0; - down(&block_subsys_sem); for (i = 0; i < ARRAY_SIZE(major_names); i++) { - for (n = major_names[i]; n; n = n->next) { - /* - * If the curent string plus the 5 extra characters - * in the line would run us off the page, then we're done - */ - if ((len + used + strlen(n->name) + 5) >= PAGE_SIZE) - goto page_full; - len += sprintf(p+len, "%3d %s\n", - n->major, n->name); - } + for (n = major_names[i]; n; n = n->next) + count++; } -page_full: - up(&block_subsys_sem); - return len; + return count; } -#endif + +/* + * extract the major and name values from a blkdev_info struct + * passed in as a void to *dev. Must be called with + * block_subsys_sem held + */ +int get_blkdev_info(void *dev, int *major, char **name) +{ + struct blkdev_info *info = dev; + + if (info->bd == NULL) + return 1; + + *major = info->bd->major; + *name = info->bd->name; + return 0; +} + int register_blkdev(unsigned int major, const char *name) { |