erofs: add sysfs node to drop internal caches

Add a sysfs node to drop compression-related caches, currently used to
drop in-memory pclusters and cached compressed folios.

Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241113041148.749129-1-guochunhai@vivo.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/Documentation/ABI/testing/sysfs-fs-erofs b/Documentation/ABI/testing/sysfs-fs-erofs
index 284224d1b56fe1bae7722d549410053c59d68cd1..b134146d735bc59d0b633eae8fd01ca53156bab6 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-erofs
+++ b/Documentation/ABI/testing/sysfs-fs-erofs
@@ -16,3 +16,14 @@ Description: Control strategy of sync decompression:
                  readahead on atomic contexts only.
                - 1 (force on): enable for readpage and readahead.
                - 2 (force off): disable for all situations.
+
+What:          /sys/fs/erofs/<disk>/drop_caches
+Date:          November 2024
+Contact:       "Guo Chunhai" <guochunhai@vivo.com>
+Description:   Writing to this will drop compression-related caches,
+               currently used to drop in-memory pclusters and cached
+               compressed folios:
+
+               - 1 : invalidate cached compressed folios
+               - 2 : drop in-memory pclusters
+               - 3 : drop in-memory pclusters and cached compressed folios

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 3905d991c49b8ededf0b72882f3ee155851671a4..0328e6b98c1b6f2c2f9881b1ed1b606581b6d26c 100644 (file)
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -450,6 +450,8 @@ static inline void erofs_pagepool_add(struct page **pagepool, struct page *page)
 void erofs_release_pages(struct page **pagepool);
 
 #ifdef CONFIG_EROFS_FS_ZIP
+#define MNGD_MAPPING(sbi)      ((sbi)->managed_cache->i_mapping)
+
 extern atomic_long_t erofs_global_shrink_cnt;
 void erofs_shrinker_register(struct super_block *sb);
 void erofs_shrinker_unregister(struct super_block *sb);

diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index 63cffd0fd26195ac4f62e22f07ac273b97a88b4d..19d586273b70915c3d5dff85c76e5a6c4dc0a2fc 100644 (file)
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -10,6 +10,7 @@
 
 enum {
        attr_feature,
+       attr_drop_caches,
        attr_pointer_ui,
        attr_pointer_bool,
 };
@@ -57,11 +58,13 @@ static struct erofs_attr erofs_attr_##_name = {                     \
 
 #ifdef CONFIG_EROFS_FS_ZIP
 EROFS_ATTR_RW_UI(sync_decompress, erofs_mount_opts);
+EROFS_ATTR_FUNC(drop_caches, 0200);
 #endif
 
 static struct attribute *erofs_attrs[] = {
 #ifdef CONFIG_EROFS_FS_ZIP
        ATTR_LIST(sync_decompress),
+       ATTR_LIST(drop_caches),
 #endif
        NULL,
 };
@@ -163,6 +166,20 @@ static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
                        return -EINVAL;
                *(bool *)ptr = !!t;
                return len;
+#ifdef CONFIG_EROFS_FS_ZIP
+       case attr_drop_caches:
+               ret = kstrtoul(skip_spaces(buf), 0, &t);
+               if (ret)
+                       return ret;
+               if (t < 1 || t > 3)
+                       return -EINVAL;
+
+               if (t & 2)
+                       z_erofs_shrink_scan(sbi, ~0UL);
+               if (t & 1)
+                       invalidate_mapping_pages(MNGD_MAPPING(sbi), 0, -1);
+               return len;
+#endif
        }
        return 0;
 }

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 877bce7709d5782f79eac0cbd15962d79b506e0a..01f14750548745803e7357c765ea9e1ee18ebae1 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -119,7 +119,6 @@ static inline unsigned int z_erofs_pclusterpages(struct z_erofs_pcluster *pcl)
        return PAGE_ALIGN(pcl->pclustersize) >> PAGE_SHIFT;
 }
 
-#define MNGD_MAPPING(sbi)      ((sbi)->managed_cache->i_mapping)
 static bool erofs_folio_is_managed(struct erofs_sb_info *sbi, struct folio *fo)
 {
        return fo->mapping == MNGD_MAPPING(sbi);