Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> --- drivers/md/dm-cache-metadata.c | 2 +- fs/super.c | 2 +- mm/shrinker.c | 16 ++++++++-------- mm/shrinker_debug.c | 14 +++++++------- 4 files changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index acffed750e3e..9e0c69958587 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -1828,7 +1828,7 @@ int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) * Replacement block manager (new_bm) is created and old_bm destroyed outside of * cmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of * shrinker associated with the block manager's bufio client vs cmd root_lock). - * - must take shrinker_rwsem without holding cmd->root_lock + * - must take shrinker_mutex without holding cmd->root_lock */ new_bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, CACHE_MAX_CONCURRENT_LOCKS); diff --git a/fs/super.c b/fs/super.c index 04643fd80886..602cf54eb7da 100644 --- a/fs/super.c +++ b/fs/super.c @@ -54,7 +54,7 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = { * One thing we have to be careful of with a per-sb shrinker is that we don't * drop the last active reference to the superblock from within the shrinker. * If that happens we could trigger unregistering the shrinker from within the - * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we + * shrinker path and that leads to deadlock on the shrinker_mutex. Hence we * take a passive reference to the superblock to avoid this from occurring. */ static unsigned long super_cache_scan(struct shrinker *shrink, diff --git a/mm/shrinker.c b/mm/shrinker.c index 90c045620fe3..5c4546d2c234 100644 --- a/mm/shrinker.c +++ b/mm/shrinker.c @@ -7,7 +7,7 @@ #include <trace/events/vmscan.h> LIST_HEAD(shrinker_list); -DECLARE_RWSEM(shrinker_rwsem); +DEFINE_MUTEX(shrinker_mutex); DEFINE_SPINLOCK(shrinker_lock); #ifdef CONFIG_MEMCG @@ -80,7 +80,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg) int nid, ret = 0; int array_size = 0; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); array_size = shrinker_unit_size(shrinker_nr_max); for_each_node(nid) { info = kvzalloc_node(sizeof(*info) + array_size, GFP_KERNEL, nid); @@ -91,7 +91,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg) goto err; rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info); } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; @@ -104,7 +104,7 @@ static struct shrinker_info *shrinker_info_protected(struct mem_cgroup *memcg, int nid) { return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, - lockdep_is_held(&shrinker_rwsem)); + lockdep_is_held(&shrinker_mutex)); } static struct shrinker_info *shrinker_info_rcu(struct mem_cgroup *memcg, @@ -158,7 +158,7 @@ static int expand_shrinker_info(int new_id) int new_size, old_size = 0; struct mem_cgroup *memcg; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); if (!root_mem_cgroup) goto out; @@ -179,7 +179,7 @@ static int expand_shrinker_info(int new_id) if (!ret) shrinker_nr_max = new_nr_max; - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; } @@ -303,7 +303,7 @@ void reparent_shrinker_deferred(struct mem_cgroup *memcg) parent = root_mem_cgroup; /* Prevent from concurrent shrinker_info expand */ - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); for_each_node(nid) { child_info = shrinker_info_protected(memcg, nid); parent_info = shrinker_info_protected(parent, nid); @@ -316,7 +316,7 @@ void reparent_shrinker_deferred(struct mem_cgroup *memcg) } } } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); } #else static int shrinker_memcg_alloc(struct shrinker *shrinker) diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index badda35464c3..44b620b1919d 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -8,7 +8,7 @@ #include <linux/rculist.h> /* defined in vmscan.c */ -extern struct rw_semaphore shrinker_rwsem; +extern struct mutex shrinker_mutex; extern struct list_head shrinker_list; static DEFINE_IDA(shrinker_debugfs_ida); @@ -168,7 +168,7 @@ int shrinker_debugfs_add(struct shrinker *shrinker) if (!shrinker_debugfs_root) return 0; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); if (shrinker->debugfs_entry) goto fail; @@ -196,7 +196,7 @@ int shrinker_debugfs_add(struct shrinker *shrinker) &shrinker_debugfs_scan_fops); fail: - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return ret; } @@ -215,7 +215,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) if (!new) return -ENOMEM; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); old = shrinker->name; shrinker->name = new; @@ -233,7 +233,7 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) shrinker->debugfs_entry = entry; } - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); kfree_const(old); @@ -246,7 +246,7 @@ struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, { struct dentry *entry = shrinker->debugfs_entry; - down_write(&shrinker_rwsem); + mutex_lock(&shrinker_mutex); kfree_const(shrinker->name); shrinker->name = NULL; @@ -257,7 +257,7 @@ struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, */ smp_wmb(); shrinker->debugfs_entry = NULL; - up_write(&shrinker_rwsem); + mutex_unlock(&shrinker_mutex); return entry; } -- 2.30.2