Instead of using class_dev_iter directly, abstract disk iteration into disk_iter and helpers which are exported. This simplifies the callers a bit and allows external users to iterate over disks.
Signed-off-by: Tejun Heo <[email protected]> --- This is one of the prep patches for ioblame which currently is in use in google. I'm working to upstream ioblame but this one seems good as a stand-alone cleanup. Thanks. block/genhd.c | 98 +++++++++++++++++++++++++++++++++----------------- include/linux/genhd.h | 10 ++++- 2 files changed, 75 insertions(+), 33 deletions(-) --- a/block/genhd.c +++ b/block/genhd.c @@ -41,6 +41,47 @@ static void disk_del_events(struct gendi static void disk_release_events(struct gendisk *disk); /** + * disk_iter_init - initialize disk iterator + * @diter: iterator to initialize + * + * Initialize @diter so that it iterates over all disks + */ +void disk_iter_init(struct disk_iter *diter) +{ + class_dev_iter_init(&diter->cdev_iter, &block_class, NULL, &disk_type); +} +EXPORT_SYMBOL_GPL(disk_iter_init); + +/** + * disk_iter_next - proceed iterator to the next disk and return it + * @diter: iterator to proceed + * + * Proceed @diter to the next disk and return it. + */ +struct gendisk *disk_iter_next(struct disk_iter *diter) +{ + struct device *dev; + + dev = class_dev_iter_next(&diter->cdev_iter); + if (dev) + return dev_to_disk(dev); + return NULL; +} +EXPORT_SYMBOL_GPL(disk_iter_next); + +/** + * disk_iter_exit - finish up disk iteration + * @diter: iter to exit + * + * Called when iteration is over. Cleans up @diter. + */ +void disk_iter_exit(struct disk_iter *diter) +{ + class_dev_iter_exit(&diter->cdev_iter); +} +EXPORT_SYMBOL_GPL(disk_iter_exit); + +/** * disk_get_part - get partition * @disk: disk to look partition from * @partno: partition number @@ -733,12 +774,11 @@ EXPORT_SYMBOL(bdget_disk); */ void __init printk_all_partitions(void) { - struct class_dev_iter iter; - struct device *dev; + struct disk_iter diter; + struct gendisk *disk; - class_dev_iter_init(&iter, &block_class, NULL, &disk_type); - while ((dev = class_dev_iter_next(&iter))) { - struct gendisk *disk = dev_to_disk(dev); + disk_iter_init(&diter); + while ((disk = disk_iter_next(&diter))) { struct disk_part_iter piter; struct hd_struct *part; char name_buf[BDEVNAME_SIZE]; @@ -778,7 +818,7 @@ void __init printk_all_partitions(void) } disk_part_iter_exit(&piter); } - class_dev_iter_exit(&iter); + disk_iter_exit(&diter); } #ifdef CONFIG_PROC_FS @@ -786,44 +826,38 @@ void __init printk_all_partitions(void) static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) { loff_t skip = *pos; - struct class_dev_iter *iter; - struct device *dev; + struct disk_iter *diter; + struct gendisk *disk; - iter = kmalloc(sizeof(*iter), GFP_KERNEL); - if (!iter) + diter = kmalloc(sizeof(*diter), GFP_KERNEL); + if (!diter) return ERR_PTR(-ENOMEM); - seqf->private = iter; - class_dev_iter_init(iter, &block_class, NULL, &disk_type); + seqf->private = diter; + disk_iter_init(diter); do { - dev = class_dev_iter_next(iter); - if (!dev) + disk = disk_iter_next(diter); + if (!disk) return NULL; } while (skip--); - return dev_to_disk(dev); + return disk; } static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) { - struct device *dev; - (*pos)++; - dev = class_dev_iter_next(seqf->private); - if (dev) - return dev_to_disk(dev); - - return NULL; + return disk_iter_next(seqf->private); } static void disk_seqf_stop(struct seq_file *seqf, void *v) { - struct class_dev_iter *iter = seqf->private; + struct disk_iter *diter = seqf->private; /* stop is called even after start failed :-( */ - if (iter) { - class_dev_iter_exit(iter); - kfree(iter); + if (diter) { + disk_iter_exit(diter); + kfree(diter); } } @@ -1205,12 +1239,12 @@ module_init(proc_genhd_init); dev_t blk_lookup_devt(const char *name, int partno) { dev_t devt = MKDEV(0, 0); - struct class_dev_iter iter; - struct device *dev; + struct disk_iter diter; + struct gendisk *disk; - class_dev_iter_init(&iter, &block_class, NULL, &disk_type); - while ((dev = class_dev_iter_next(&iter))) { - struct gendisk *disk = dev_to_disk(dev); + disk_iter_init(&diter); + while ((disk = disk_iter_next(&diter))) { + struct device *dev = disk_to_dev(disk); struct hd_struct *part; if (strcmp(dev_name(dev), name)) @@ -1232,7 +1266,7 @@ dev_t blk_lookup_devt(const char *name, } disk_put_part(part); } - class_dev_iter_exit(&iter); + disk_iter_exit(&diter); return devt; } EXPORT_SYMBOL(blk_lookup_devt); --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -263,8 +263,16 @@ static inline void disk_put_part(struct } /* - * Smarter partition iterator without context limits. + * Smarter disk and partition iterators without context limits. */ +struct disk_iter { + struct class_dev_iter cdev_iter; +}; + +extern void disk_iter_init(struct disk_iter *diter); +extern struct gendisk *disk_iter_next(struct disk_iter *diter); +extern void disk_iter_exit(struct disk_iter *diter); + #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */ #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */ #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
