From 2ac3cee5298a247b2774f3319b28a05f588c3f0e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 3 Sep 2008 08:53:37 +0200 Subject: [PATCH] block: don't grab block_class_lock unnecessarily block_class_lock protects major_names array and bdev_map and doesn't have anything to do with block class devices. Don't grab them while iterating over block class devices. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/genhd.c | 28 +++++++++------------------- 1 file changed, 9 insertions(+), 19 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 0be95135c404..9eb8b3e212c1 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -283,9 +283,7 @@ static int printk_partition(struct device *dev, void *data) */ void __init printk_all_partitions(void) { - mutex_lock(&block_class_lock); class_for_each_device(&block_class, NULL, NULL, printk_partition); - mutex_unlock(&block_class_lock); } #ifdef CONFIG_PROC_FS @@ -305,17 +303,15 @@ static int find_start(struct device *dev, void *data) static void *part_start(struct seq_file *part, loff_t *pos) { struct device *dev; - loff_t k = *pos; + loff_t n = *pos; - if (!k) + if (!n) part->private = (void *)1LU; /* tell show to print header */ - mutex_lock(&block_class_lock); - dev = class_find_device(&block_class, NULL, &k, find_start); - if (dev) { - put_device(dev); + dev = class_find_device(&block_class, NULL, &n, find_start); + if (dev) return dev_to_disk(dev); - } + return NULL; } @@ -341,7 +337,6 @@ static void *part_next(struct seq_file *part, void *v, loff_t *pos) static void part_stop(struct seq_file *part, void *v) { - mutex_unlock(&block_class_lock); } static int show_partition(struct seq_file *part, void *v) @@ -583,14 +578,12 @@ static struct device_type disk_type = { static void *diskstats_start(struct seq_file *part, loff_t *pos) { struct device *dev; - loff_t k = *pos; + loff_t n = *pos; - mutex_lock(&block_class_lock); - dev = class_find_device(&block_class, NULL, &k, find_start); - if (dev) { - put_device(dev); + dev = class_find_device(&block_class, NULL, &n, find_start); + if (dev) return dev_to_disk(dev); - } + return NULL; } @@ -610,7 +603,6 @@ static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos) static void diskstats_stop(struct seq_file *part, void *v) { - mutex_unlock(&block_class_lock); } static int diskstats_show(struct seq_file *s, void *v) @@ -729,7 +721,6 @@ dev_t blk_lookup_devt(const char *name, int part) dev_t devt = MKDEV(0, 0); struct find_block find; - mutex_lock(&block_class_lock); find.name = name; find.part = part; dev = class_find_device(&block_class, NULL, &find, match_id); @@ -738,7 +729,6 @@ dev_t blk_lookup_devt(const char *name, int part) devt = MKDEV(MAJOR(dev->devt), MINOR(dev->devt) + part); } - mutex_unlock(&block_class_lock); return devt; } -- GitLab