From e49fbbbf0aa14f011ab037086f37f58bd058a6ee Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 29 Oct 2020 15:58:26 +0100 Subject: [PATCH] block: split block_class_lock Split the block_class_lock mutex into one each to protect bdev_map and major_names. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/genhd.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 667d1d6..8226add 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -25,7 +25,6 @@ #include "blk.h" -static DEFINE_MUTEX(block_class_lock); static struct kobject *block_depr; struct bdev_map { @@ -37,6 +36,7 @@ struct bdev_map { int (*lock)(dev_t, void *); void *data; } *bdev_map[255]; +static DEFINE_MUTEX(bdev_map_lock); /* for extended dynamic devt allocation, currently only one major is used */ #define NR_EXT_DEVT (1 << MINORBITS) @@ -403,6 +403,7 @@ static struct blk_major_name { int major; char name[16]; } *major_names[BLKDEV_MAJOR_HASH_SIZE]; +static DEFINE_MUTEX(major_names_lock); /* index in the above - for now: assume no multimajor ranges */ static inline int major_to_index(unsigned major) @@ -415,11 +416,11 @@ void blkdev_show(struct seq_file *seqf, off_t offset) { struct blk_major_name *dp; - mutex_lock(&block_class_lock); + mutex_lock(&major_names_lock); for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next) if (dp->major == offset) seq_printf(seqf, "%3d %s\n", dp->major, dp->name); - mutex_unlock(&block_class_lock); + mutex_unlock(&major_names_lock); } #endif /* CONFIG_PROC_FS */ @@ -448,7 +449,7 @@ int register_blkdev(unsigned int major, const char *name) struct blk_major_name **n, *p; int index, ret = 0; - mutex_lock(&block_class_lock); + mutex_lock(&major_names_lock); /* temporary */ if (major == 0) { @@ -501,7 +502,7 @@ int register_blkdev(unsigned int major, const char *name) kfree(p); } out: - mutex_unlock(&block_class_lock); + mutex_unlock(&major_names_lock); return ret; } @@ -513,7 +514,7 @@ void unregister_blkdev(unsigned int major, const char *name) struct blk_major_name *p = NULL; int index = major_to_index(major); - mutex_lock(&block_class_lock); + mutex_lock(&major_names_lock); for (n = &major_names[index]; *n; n = &(*n)->next) if ((*n)->major == major) break; @@ -523,7 +524,7 @@ void unregister_blkdev(unsigned int major, const char *name) p = *n; *n = p->next; } - mutex_unlock(&block_class_lock); + mutex_unlock(&major_names_lock); kfree(p); } @@ -674,7 +675,7 @@ void blk_register_region(dev_t devt, unsigned long range, struct module *module, p->data = data; } - mutex_lock(&block_class_lock); + mutex_lock(&bdev_map_lock); for (i = 0, p -= n; i < n; i++, p++, index++) { struct bdev_map **s = &bdev_map[index % 255]; while (*s && (*s)->range < range) @@ -682,7 +683,7 @@ void blk_register_region(dev_t devt, unsigned long range, struct module *module, p->next = *s; *s = p; } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); } EXPORT_SYMBOL(blk_register_region); @@ -693,7 +694,7 @@ void blk_unregister_region(dev_t devt, unsigned long range) unsigned i; struct bdev_map *found = NULL; - mutex_lock(&block_class_lock); + mutex_lock(&bdev_map_lock); for (i = 0; i < min(n, 255u); i++, index++) { struct bdev_map **s; for (s = &bdev_map[index % 255]; *s; s = &(*s)->next) { @@ -706,7 +707,7 @@ void blk_unregister_region(dev_t devt, unsigned long range) } } } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); kfree(found); } EXPORT_SYMBOL(blk_unregister_region); @@ -1037,7 +1038,7 @@ static struct gendisk *lookup_gendisk(dev_t dev, int *partno) unsigned long best = ~0UL; retry: - mutex_lock(&block_class_lock); + mutex_lock(&bdev_map_lock); for (p = bdev_map[MAJOR(dev) % 255]; p; p = p->next) { struct kobject *(*probe)(dev_t, int *, void *); struct module *owner; @@ -1058,7 +1059,7 @@ retry: module_put(owner); continue; } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); kobj = probe(dev, partno, data); /* Currently ->owner protects _only_ ->probe() itself. */ module_put(owner); @@ -1066,7 +1067,7 @@ retry: return dev_to_disk(kobj_to_dev(kobj)); goto retry; } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); return NULL; } -- 2.7.4