mm: shrinkers: provide shrinkers with names

Currently shrinkers are anonymous objects.  For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g.  for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.

This commit adds names to shrinkers.  register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.

In some cases it's not possible to determine a good name at the time when
a shrinker is allocated.  For such cases shrinker_debugfs_rename() is
provided.

The expected format is:
    <subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.

After this change the shrinker debugfs directory looks like:
  $ cd /sys/kernel/debug/shrinker/
  $ ls
    dquota-cache-16     sb-devpts-28     sb-proc-47       sb-tmpfs-42
    mm-shadow-18        sb-devtmpfs-5    sb-proc-48       sb-tmpfs-43
    mm-zspool:zram0-34  sb-hugetlbfs-17  sb-pstore-31     sb-tmpfs-44
    rcu-kfree-0         sb-hugetlbfs-33  sb-rootfs-2      sb-tmpfs-49
    sb-aio-20           sb-iomem-12      sb-securityfs-6  sb-tracefs-13
    sb-anon_inodefs-15  sb-mqueue-21     sb-selinuxfs-22  sb-xfs:vda1-36
    sb-bdev-3           sb-nsfs-4        sb-sockfs-8      sb-zsmalloc-19
    sb-bpf-32           sb-pipefs-14     sb-sysfs-26      thp-deferred_split-10
    sb-btrfs:vda2-24    sb-proc-25       sb-tmpfs-1       thp-zero-9
    sb-cgroup2-30       sb-proc-39       sb-tmpfs-27      xfs-buf:vda1-37
    sb-configfs-23      sb-proc-41       sb-tmpfs-29      xfs-inodegc:vda1-38
    sb-dax-11           sb-proc-45       sb-tmpfs-35
    sb-debugfs-7        sb-proc-46       sb-tmpfs-40

[roman.gushchin@linux.dev: fix build warnings]
  Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
  Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

18 files changed, 31 insertions, 19 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 6627dd7875ee..eee3e96d877f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1815,6 +1815,8 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 			error = -EBUSY;
 	} else {
 		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
+		shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s", fs_type->name,
+					s->s_id);
 		btrfs_sb(s)->bdev_holder = fs_type;
 		if (!strstr(crc32c_impl(), "generic"))
 			set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index ec9a1d780dc1..46627cb69abe 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -282,7 +282,7 @@ static struct shrinker erofs_shrinker_info = {
 
 int __init erofs_init_shrinker(void)
 {
-	return register_shrinker(&erofs_shrinker_info);
+	return register_shrinker(&erofs_shrinker_info, "erofs-shrinker");
 }
 
 void erofs_exit_shrinker(void)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 9a3a8996aacf..23167efda95e 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1654,7 +1654,8 @@ int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
 	sbi->s_es_shrinker.scan_objects = ext4_es_scan;
 	sbi->s_es_shrinker.count_objects = ext4_es_count;
 	sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
-	err = register_shrinker(&sbi->s_es_shrinker);
+	err = register_shrinker(&sbi->s_es_shrinker, "ext4-es:%s",
+				sbi->s_sb->s_id);
 	if (err)
 		goto err4;
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 37221e94e5ef..bce02306f7a0 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4579,7 +4579,7 @@ static int __init init_f2fs_fs(void)
 	err = f2fs_init_sysfs();
 	if (err)
 		goto free_garbage_collection_cache;
-	err = register_shrinker(&f2fs_shrinker_info);
+	err = register_shrinker(&f2fs_shrinker_info, "f2fs-shrinker");
 	if (err)
 		goto free_sysfs;
 	err = register_filesystem(&f2fs_fs_type);
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index c992d53013d3..dca842379cab 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2533,7 +2533,7 @@ int __init gfs2_glock_init(void)
 		return -ENOMEM;
 	}
 
-	ret = register_shrinker(&glock_shrinker);
+	ret = register_shrinker(&glock_shrinker, "gfs2-glock");
 	if (ret) {
 		destroy_workqueue(gfs2_delete_workqueue);
 		destroy_workqueue(glock_workqueue);
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index 244187e3e70f..b66a3e1ec152 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -148,7 +148,7 @@ static int __init init_gfs2_fs(void)
 	if (!gfs2_trans_cachep)
 		goto fail_cachep8;
 
-	error = register_shrinker(&gfs2_qd_shrinker);
+	error = register_shrinker(&gfs2_qd_shrinker, "gfs2-qd");
 	if (error)
 		goto fail_shrinker;
 
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index c0cbeeaec2d1..45e4655c8033 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1418,7 +1418,8 @@ static journal_t *journal_init_common(struct block_device *bdev,
 	if (percpu_counter_init(&journal->j_checkpoint_jh_count, 0, GFP_KERNEL))
 		goto err_cleanup;
 
-	if (register_shrinker(&journal->j_shrinker)) {
+	if (register_shrinker(&journal->j_shrinker, "jbd2-journal:(%u:%u)",
+			      MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev))) {
 		percpu_counter_destroy(&journal->j_checkpoint_jh_count);
 		goto err_cleanup;
 	}
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 97c54d3a2227..0b833da0a9a5 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -367,7 +367,7 @@ struct mb_cache *mb_cache_create(int bucket_bits)
 	cache->c_shrink.count_objects = mb_cache_count;
 	cache->c_shrink.scan_objects = mb_cache_scan;
 	cache->c_shrink.seeks = DEFAULT_SEEKS;
-	if (register_shrinker(&cache->c_shrink)) {
+	if (register_shrinker(&cache->c_shrink, "mbcache-shrinker")) {
 		kfree(cache->c_hash);
 		kfree(cache);
 		goto err_out;
diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c
index e7b34f7e0614..a9bf09fdf2c3 100644
--- a/fs/nfs/nfs42xattr.c
+++ b/fs/nfs/nfs42xattr.c
@@ -1017,15 +1017,16 @@ int __init nfs4_xattr_cache_init(void)
 	if (ret)
 		goto out2;
 
-	ret = register_shrinker(&nfs4_xattr_cache_shrinker);
+	ret = register_shrinker(&nfs4_xattr_cache_shrinker, "nfs-xattr_cache");
 	if (ret)
 		goto out1;
 
-	ret = register_shrinker(&nfs4_xattr_entry_shrinker);
+	ret = register_shrinker(&nfs4_xattr_entry_shrinker, "nfs-xattr_entry");
 	if (ret)
 		goto out;
 
-	ret = register_shrinker(&nfs4_xattr_large_entry_shrinker);
+	ret = register_shrinker(&nfs4_xattr_large_entry_shrinker,
+				"nfs-xattr_large_entry");
 	if (!ret)
 		return 0;
 
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6ab5eeb000dc..82944e14fcea 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -149,7 +149,7 @@ int __init register_nfs_fs(void)
 	ret = nfs_register_sysctl();
 	if (ret < 0)
 		goto error_2;
-	ret = register_shrinker(&acl_shrinker);
+	ret = register_shrinker(&acl_shrinker, "nfs-acl");
 	if (ret < 0)
 		goto error_3;
 #ifdef CONFIG_NFS_V4_2
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 9cb2d590c036..a605c0e39b09 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -670,7 +670,7 @@ nfsd_file_cache_init(void)
 		goto out_err;
 	}
 
-	ret = register_shrinker(&nfsd_file_shrinker);
+	ret = register_shrinker(&nfsd_file_shrinker, "nfsd-filecache");
 	if (ret) {
 		pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", ret);
 		goto out_lru;
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 7da88bdc0d6c..9b31e1103e7b 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -176,7 +176,8 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 	nn->nfsd_reply_cache_shrinker.scan_objects = nfsd_reply_cache_scan;
 	nn->nfsd_reply_cache_shrinker.count_objects = nfsd_reply_cache_count;
 	nn->nfsd_reply_cache_shrinker.seeks = 1;
-	status = register_shrinker(&nn->nfsd_reply_cache_shrinker);
+	status = register_shrinker(&nn->nfsd_reply_cache_shrinker,
+				   "nfsd-reply:%s", nn->nfsd_name);
 	if (status)
 		goto out_stats_destroy;
 
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 09d1307959d0..e0b659900e70 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2995,7 +2995,7 @@ static int __init dquot_init(void)
 	pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
 		" %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
 
-	if (register_shrinker(&dqcache_shrinker))
+	if (register_shrinker(&dqcache_shrinker, "dquota-cache"))
 		panic("Cannot register dquot shrinker");
 
 	return 0;
diff --git a/fs/super.c b/fs/super.c
index 60f57c7bc0a6..4fca6657f442 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -265,7 +265,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
 	s->s_shrink.count_objects = super_cache_count;
 	s->s_shrink.batch = 1024;
 	s->s_shrink.flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE;
-	if (prealloc_shrinker(&s->s_shrink))
+	if (prealloc_shrinker(&s->s_shrink, "sb-%s", type->name))
 		goto fail;
 	if (list_lru_init_memcg(&s->s_dentry_lru, &s->s_shrink))
 		goto fail;
@@ -1288,6 +1288,8 @@ int get_tree_bdev(struct fs_context *fc,
 	} else {
 		s->s_mode = mode;
 		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
+		shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s",
+					fc->fs_type->name, s->s_id);
 		sb_set_blocksize(s, block_size(bdev));
 		error = fill_super(s, fc);
 		if (error) {
@@ -1363,6 +1365,8 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
 	} else {
 		s->s_mode = mode;
 		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
+		shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s",
+					fs_type->name, s->s_id);
 		sb_set_blocksize(s, block_size(bdev));
 		error = fill_super(s, data, flags & SB_SILENT ? 1 : 0);
 		if (error) {
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 0978d01b0ea4..d0c9a09988bc 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -2430,7 +2430,7 @@ static int __init ubifs_init(void)
 	if (!ubifs_inode_slab)
 		return -ENOMEM;
 
-	err = register_shrinker(&ubifs_shrinker_info);
+	err = register_shrinker(&ubifs_shrinker_info, "ubifs-slab");
 	if (err)
 		goto out_slab;
 
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index bf4e60871068..4aa9c9cf5b6e 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1986,7 +1986,8 @@ xfs_alloc_buftarg(
 	btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan;
 	btp->bt_shrinker.seeks = DEFAULT_SEEKS;
 	btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE;
-	if (register_shrinker(&btp->bt_shrinker))
+	if (register_shrinker(&btp->bt_shrinker, "xfs-buf:%s",
+			      mp->m_super->s_id))
 		goto error_pcpu;
 	return btp;
 
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 5269354b1b69..a1941c8b8630 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -2201,5 +2201,5 @@ xfs_inodegc_register_shrinker(
 	shrink->flags = SHRINKER_NONSLAB;
 	shrink->batch = XFS_INODEGC_SHRINKER_BATCH;
 
-	return register_shrinker(shrink);
+	return register_shrinker(shrink, "xfs-inodegc:%s", mp->m_super->s_id);
 }
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index abf08bbf34a9..c31d57453ceb 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -677,7 +677,8 @@ xfs_qm_init_quotainfo(
 	qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
 	qinf->qi_shrinker.flags = SHRINKER_NUMA_AWARE;
 
-	error = register_shrinker(&qinf->qi_shrinker);
+	error = register_shrinker(&qinf->qi_shrinker, "xfs-qm:%s",
+				  mp->m_super->s_id);
 	if (error)
 		goto out_free_inos;