Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 647 insertions, 0 deletions

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
new file mode 100644
index 000000000..d8d09fc3e
--- /dev/null
+++ b/fs/erofs/internal.h
@@ -0,0 +1,647 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
+ */
+#ifndef __EROFS_INTERNAL_H
+#define __EROFS_INTERNAL_H
+
+#include <linux/fs.h>
+#include <linux/dcache.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/magic.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/iomap.h>
+#include "erofs_fs.h"
+
+/* redefine pr_fmt "erofs: " */
+#undef pr_fmt
+#define pr_fmt(fmt) "erofs: " fmt
+
+__printf(3, 4) void _erofs_err(struct super_block *sb,
+			       const char *function, const char *fmt, ...);
+#define erofs_err(sb, fmt, ...)	\
+	_erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__)
+__printf(3, 4) void _erofs_info(struct super_block *sb,
+			       const char *function, const char *fmt, ...);
+#define erofs_info(sb, fmt, ...) \
+	_erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__)
+#ifdef CONFIG_EROFS_FS_DEBUG
+#define erofs_dbg(x, ...)       pr_debug(x "\n", ##__VA_ARGS__)
+#define DBG_BUGON               BUG_ON
+#else
+#define erofs_dbg(x, ...)       ((void)0)
+#define DBG_BUGON(x)            ((void)(x))
+#endif	/* !CONFIG_EROFS_FS_DEBUG */
+
+/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
+#define EROFS_SUPER_MAGIC   EROFS_SUPER_MAGIC_V1
+
+typedef u64 erofs_nid_t;
+typedef u64 erofs_off_t;
+/* data type for filesystem-wide blocks number */
+typedef u32 erofs_blk_t;
+
+struct erofs_device_info {
+	char *path;
+	struct erofs_fscache *fscache;
+	struct block_device *bdev;
+	struct dax_device *dax_dev;
+	u64 dax_part_off;
+
+	u32 blocks;
+	u32 mapped_blkaddr;
+};
+
+enum {
+	EROFS_SYNC_DECOMPRESS_AUTO,
+	EROFS_SYNC_DECOMPRESS_FORCE_ON,
+	EROFS_SYNC_DECOMPRESS_FORCE_OFF
+};
+
+struct erofs_mount_opts {
+#ifdef CONFIG_EROFS_FS_ZIP
+	/* current strategy of how to use managed cache */
+	unsigned char cache_strategy;
+	/* strategy of sync decompression (0 - auto, 1 - force on, 2 - force off) */
+	unsigned int sync_decompress;
+
+	/* threshold for decompression synchronously */
+	unsigned int max_sync_decompress_pages;
+#endif
+	unsigned int mount_opt;
+};
+
+struct erofs_dev_context {
+	struct idr tree;
+	struct rw_semaphore rwsem;
+
+	unsigned int extra_devices;
+};
+
+struct erofs_fs_context {
+	struct erofs_mount_opts opt;
+	struct erofs_dev_context *devs;
+	char *fsid;
+	char *domain_id;
+};
+
+/* all filesystem-wide lz4 configurations */
+struct erofs_sb_lz4_info {
+	/* # of pages needed for EROFS lz4 rolling decompression */
+	u16 max_distance_pages;
+	/* maximum possible blocks for pclusters in the filesystem */
+	u16 max_pclusterblks;
+};
+
+struct erofs_domain {
+	refcount_t ref;
+	struct list_head list;
+	struct fscache_volume *volume;
+	char *domain_id;
+};
+
+struct erofs_fscache {
+	struct fscache_cookie *cookie;
+	struct inode *inode;
+	struct inode *anon_inode;
+	struct erofs_domain *domain;
+	char *name;
+};
+
+struct erofs_sb_info {
+	struct erofs_mount_opts opt;	/* options */
+#ifdef CONFIG_EROFS_FS_ZIP
+	/* list for all registered superblocks, mainly for shrinker */
+	struct list_head list;
+	struct mutex umount_mutex;
+
+	/* managed XArray arranged in physical block number */
+	struct xarray managed_pslots;
+
+	unsigned int shrinker_run_no;
+	u16 available_compr_algs;
+
+	/* pseudo inode to manage cached pages */
+	struct inode *managed_cache;
+
+	struct erofs_sb_lz4_info lz4;
+	struct inode *packed_inode;
+#endif	/* CONFIG_EROFS_FS_ZIP */
+	struct erofs_dev_context *devs;
+	struct dax_device *dax_dev;
+	u64 dax_part_off;
+	u64 total_blocks;
+	u32 primarydevice_blocks;
+
+	u32 meta_blkaddr;
+#ifdef CONFIG_EROFS_FS_XATTR
+	u32 xattr_blkaddr;
+#endif
+	u16 device_id_mask;	/* valid bits of device id to be used */
+
+	/* inode slot unit size in bit shift */
+	unsigned char islotbits;
+
+	u32 sb_size;			/* total superblock size */
+	u32 build_time_nsec;
+	u64 build_time;
+
+	/* what we really care is nid, rather than ino.. */
+	erofs_nid_t root_nid;
+	erofs_nid_t packed_nid;
+	/* used for statfs, f_files - f_favail */
+	u64 inos;
+
+	u8 uuid[16];                    /* 128-bit uuid for volume */
+	u8 volume_name[16];             /* volume name */
+	u32 feature_compat;
+	u32 feature_incompat;
+
+	/* sysfs support */
+	struct kobject s_kobj;		/* /sys/fs/erofs/<devname> */
+	struct completion s_kobj_unregister;
+
+	/* fscache support */
+	struct fscache_volume *volume;
+	struct erofs_fscache *s_fscache;
+	struct erofs_domain *domain;
+	char *fsid;
+	char *domain_id;
+};
+
+#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
+#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
+
+/* Mount flags set via mount options or defaults */
+#define EROFS_MOUNT_XATTR_USER		0x00000010
+#define EROFS_MOUNT_POSIX_ACL		0x00000020
+#define EROFS_MOUNT_DAX_ALWAYS		0x00000040
+#define EROFS_MOUNT_DAX_NEVER		0x00000080
+
+#define clear_opt(opt, option)	((opt)->mount_opt &= ~EROFS_MOUNT_##option)
+#define set_opt(opt, option)	((opt)->mount_opt |= EROFS_MOUNT_##option)
+#define test_opt(opt, option)	((opt)->mount_opt & EROFS_MOUNT_##option)
+
+static inline bool erofs_is_fscache_mode(struct super_block *sb)
+{
+	return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !sb->s_bdev;
+}
+
+enum {
+	EROFS_ZIP_CACHE_DISABLED,
+	EROFS_ZIP_CACHE_READAHEAD,
+	EROFS_ZIP_CACHE_READAROUND
+};
+
+#define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
+
+/* basic unit of the workstation of a super_block */
+struct erofs_workgroup {
+	/* the workgroup index in the workstation */
+	pgoff_t index;
+
+	/* overall workgroup reference count */
+	atomic_t refcount;
+};
+
+static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
+						 int val)
+{
+	preempt_disable();
+	if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
+		preempt_enable();
+		return false;
+	}
+	return true;
+}
+
+static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
+					    int orig_val)
+{
+	/*
+	 * other observers should notice all modifications
+	 * in the freezing period.
+	 */
+	smp_mb();
+	atomic_set(&grp->refcount, orig_val);
+	preempt_enable();
+}
+
+static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
+{
+	return atomic_cond_read_relaxed(&grp->refcount,
+					VAL != EROFS_LOCKED_MAGIC);
+}
+
+/* we strictly follow PAGE_SIZE and no buffer head yet */
+#define LOG_BLOCK_SIZE		PAGE_SHIFT
+
+#undef LOG_SECTORS_PER_BLOCK
+#define LOG_SECTORS_PER_BLOCK	(PAGE_SHIFT - 9)
+
+#undef SECTORS_PER_BLOCK
+#define SECTORS_PER_BLOCK	(1 << SECTORS_PER_BLOCK)
+
+#define EROFS_BLKSIZ		(1 << LOG_BLOCK_SIZE)
+
+#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
+#error erofs cannot be used in this platform
+#endif
+
+enum erofs_kmap_type {
+	EROFS_NO_KMAP,		/* don't map the buffer */
+	EROFS_KMAP,		/* use kmap() to map the buffer */
+	EROFS_KMAP_ATOMIC,	/* use kmap_atomic() to map the buffer */
+};
+
+struct erofs_buf {
+	struct page *page;
+	void *base;
+	enum erofs_kmap_type kmap_type;
+};
+#define __EROFS_BUF_INITIALIZER	((struct erofs_buf){ .page = NULL })
+
+#define ROOT_NID(sb)		((sb)->root_nid)
+
+#define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
+#define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
+#define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
+
+#define EROFS_FEATURE_FUNCS(name, compat, feature) \
+static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
+{ \
+	return sbi->feature_##compat & EROFS_FEATURE_##feature; \
+}
+
+EROFS_FEATURE_FUNCS(zero_padding, incompat, INCOMPAT_ZERO_PADDING)
+EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
+EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
+EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
+EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
+EROFS_FEATURE_FUNCS(compr_head2, incompat, INCOMPAT_COMPR_HEAD2)
+EROFS_FEATURE_FUNCS(ztailpacking, incompat, INCOMPAT_ZTAILPACKING)
+EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS)
+EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE)
+EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
+
+/* atomic flag definitions */
+#define EROFS_I_EA_INITED_BIT	0
+#define EROFS_I_Z_INITED_BIT	1
+
+/* bitlock definitions (arranged in reverse order) */
+#define EROFS_I_BL_XATTR_BIT	(BITS_PER_LONG - 1)
+#define EROFS_I_BL_Z_BIT	(BITS_PER_LONG - 2)
+
+struct erofs_inode {
+	erofs_nid_t nid;
+
+	/* atomic flags (including bitlocks) */
+	unsigned long flags;
+
+	unsigned char datalayout;
+	unsigned char inode_isize;
+	unsigned int xattr_isize;
+
+	unsigned int xattr_shared_count;
+	unsigned int *xattr_shared_xattrs;
+
+	union {
+		erofs_blk_t raw_blkaddr;
+		struct {
+			unsigned short	chunkformat;
+			unsigned char	chunkbits;
+		};
+#ifdef CONFIG_EROFS_FS_ZIP
+		struct {
+			unsigned short z_advise;
+			unsigned char  z_algorithmtype[2];
+			unsigned char  z_logical_clusterbits;
+			unsigned long  z_tailextent_headlcn;
+			union {
+				struct {
+					erofs_off_t    z_idataoff;
+					unsigned short z_idata_size;
+				};
+				erofs_off_t z_fragmentoff;
+			};
+		};
+#endif	/* CONFIG_EROFS_FS_ZIP */
+	};
+	/* the corresponding vfs inode */
+	struct inode vfs_inode;
+};
+
+#define EROFS_I(ptr)	container_of(ptr, struct erofs_inode, vfs_inode)
+
+static inline erofs_off_t erofs_iloc(struct inode *inode)
+{
+	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+
+	return blknr_to_addr(sbi->meta_blkaddr) +
+		(EROFS_I(inode)->nid << sbi->islotbits);
+}
+
+static inline unsigned long erofs_inode_datablocks(struct inode *inode)
+{
+	/* since i_size cannot be changed */
+	return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+}
+
+static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
+					  unsigned int bits)
+{
+
+	return (value >> bit) & ((1 << bits) - 1);
+}
+
+
+static inline unsigned int erofs_inode_version(unsigned int value)
+{
+	return erofs_bitrange(value, EROFS_I_VERSION_BIT,
+			      EROFS_I_VERSION_BITS);
+}
+
+static inline unsigned int erofs_inode_datalayout(unsigned int value)
+{
+	return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
+			      EROFS_I_DATALAYOUT_BITS);
+}
+
+/*
+ * Different from grab_cache_page_nowait(), reclaiming is never triggered
+ * when allocating new pages.
+ */
+static inline
+struct page *erofs_grab_cache_page_nowait(struct address_space *mapping,
+					  pgoff_t index)
+{
+	return pagecache_get_page(mapping, index,
+			FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
+			readahead_gfp_mask(mapping) & ~__GFP_RECLAIM);
+}
+
+extern const struct super_operations erofs_sops;
+extern struct file_system_type erofs_fs_type;
+
+extern const struct address_space_operations erofs_raw_access_aops;
+extern const struct address_space_operations z_erofs_aops;
+
+enum {
+	BH_Encoded = BH_PrivateStart,
+	BH_FullMapped,
+	BH_Fragment,
+	BH_Partialref,
+};
+
+/* Has a disk mapping */
+#define EROFS_MAP_MAPPED	(1 << BH_Mapped)
+/* Located in metadata (could be copied from bd_inode) */
+#define EROFS_MAP_META		(1 << BH_Meta)
+/* The extent is encoded */
+#define EROFS_MAP_ENCODED	(1 << BH_Encoded)
+/* The length of extent is full */
+#define EROFS_MAP_FULL_MAPPED	(1 << BH_FullMapped)
+/* Located in the special packed inode */
+#define EROFS_MAP_FRAGMENT	(1 << BH_Fragment)
+/* The extent refers to partial decompressed data */
+#define EROFS_MAP_PARTIAL_REF	(1 << BH_Partialref)
+
+struct erofs_map_blocks {
+	struct erofs_buf buf;
+
+	erofs_off_t m_pa, m_la;
+	u64 m_plen, m_llen;
+
+	unsigned short m_deviceid;
+	char m_algorithmformat;
+	unsigned int m_flags;
+};
+
+/* Flags used by erofs_map_blocks_flatmode() */
+#define EROFS_GET_BLOCKS_RAW    0x0001
+/*
+ * Used to get the exact decompressed length, e.g. fiemap (consider lookback
+ * approach instead if possible since it's more metadata lightweight.)
+ */
+#define EROFS_GET_BLOCKS_FIEMAP	0x0002
+/* Used to map the whole extent if non-negligible data is requested for LZMA */
+#define EROFS_GET_BLOCKS_READMORE	0x0004
+/* Used to map tail extent for tailpacking inline or fragment pcluster */
+#define EROFS_GET_BLOCKS_FINDTAIL	0x0008
+
+enum {
+	Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
+	Z_EROFS_COMPRESSION_INTERLACED,
+	Z_EROFS_COMPRESSION_RUNTIME_MAX
+};
+
+/* zmap.c */
+extern const struct iomap_ops z_erofs_iomap_report_ops;
+
+#ifdef CONFIG_EROFS_FS_ZIP
+int z_erofs_fill_inode(struct inode *inode);
+int z_erofs_map_blocks_iter(struct inode *inode,
+			    struct erofs_map_blocks *map,
+			    int flags);
+#else
+static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
+static inline int z_erofs_map_blocks_iter(struct inode *inode,
+					  struct erofs_map_blocks *map,
+					  int flags)
+{
+	return -EOPNOTSUPP;
+}
+#endif	/* !CONFIG_EROFS_FS_ZIP */
+
+struct erofs_map_dev {
+	struct erofs_fscache *m_fscache;
+	struct block_device *m_bdev;
+	struct dax_device *m_daxdev;
+	u64 m_dax_part_off;
+
+	erofs_off_t m_pa;
+	unsigned int m_deviceid;
+};
+
+/* data.c */
+extern const struct file_operations erofs_file_fops;
+void erofs_unmap_metabuf(struct erofs_buf *buf);
+void erofs_put_metabuf(struct erofs_buf *buf);
+void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
+		  erofs_blk_t blkaddr, enum erofs_kmap_type type);
+void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
+			 erofs_blk_t blkaddr, enum erofs_kmap_type type);
+int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *dev);
+int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		 u64 start, u64 len);
+int erofs_map_blocks(struct inode *inode,
+		     struct erofs_map_blocks *map, int flags);
+
+/* inode.c */
+static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
+{
+#if BITS_PER_LONG == 32
+	return (nid >> 32) ^ (nid & 0xffffffff);
+#else
+	return nid;
+#endif
+}
+
+extern const struct inode_operations erofs_generic_iops;
+extern const struct inode_operations erofs_symlink_iops;
+extern const struct inode_operations erofs_fast_symlink_iops;
+
+struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid);
+int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+		  struct kstat *stat, u32 request_mask,
+		  unsigned int query_flags);
+
+/* namei.c */
+extern const struct inode_operations erofs_dir_iops;
+
+int erofs_namei(struct inode *dir, const struct qstr *name,
+		erofs_nid_t *nid, unsigned int *d_type);
+
+/* dir.c */
+extern const struct file_operations erofs_dir_fops;
+
+static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
+{
+	int retried = 0;
+
+	while (1) {
+		void *p = vm_map_ram(pages, count, -1);
+
+		/* retry two more times (totally 3 times) */
+		if (p || ++retried >= 3)
+			return p;
+		vm_unmap_aliases();
+	}
+	return NULL;
+}
+
+/* pcpubuf.c */
+void *erofs_get_pcpubuf(unsigned int requiredpages);
+void erofs_put_pcpubuf(void *ptr);
+int erofs_pcpubuf_growsize(unsigned int nrpages);
+void erofs_pcpubuf_init(void);
+void erofs_pcpubuf_exit(void);
+
+/* sysfs.c */
+int erofs_register_sysfs(struct super_block *sb);
+void erofs_unregister_sysfs(struct super_block *sb);
+int __init erofs_init_sysfs(void);
+void erofs_exit_sysfs(void);
+
+/* utils.c / zdata.c */
+struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp);
+static inline void erofs_pagepool_add(struct page **pagepool,
+		struct page *page)
+{
+	set_page_private(page, (unsigned long)*pagepool);
+	*pagepool = page;
+}
+void erofs_release_pages(struct page **pagepool);
+
+#ifdef CONFIG_EROFS_FS_ZIP
+int erofs_workgroup_put(struct erofs_workgroup *grp);
+struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
+					     pgoff_t index);
+struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
+					       struct erofs_workgroup *grp);
+void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
+void erofs_shrinker_register(struct super_block *sb);
+void erofs_shrinker_unregister(struct super_block *sb);
+int __init erofs_init_shrinker(void);
+void erofs_exit_shrinker(void);
+int __init z_erofs_init_zip_subsystem(void);
+void z_erofs_exit_zip_subsystem(void);
+int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+				       struct erofs_workgroup *egrp);
+int erofs_try_to_free_cached_page(struct page *page);
+int z_erofs_load_lz4_config(struct super_block *sb,
+			    struct erofs_super_block *dsb,
+			    struct z_erofs_lz4_cfgs *lz4, int len);
+#else
+static inline void erofs_shrinker_register(struct super_block *sb) {}
+static inline void erofs_shrinker_unregister(struct super_block *sb) {}
+static inline int erofs_init_shrinker(void) { return 0; }
+static inline void erofs_exit_shrinker(void) {}
+static inline int z_erofs_init_zip_subsystem(void) { return 0; }
+static inline void z_erofs_exit_zip_subsystem(void) {}
+static inline int z_erofs_load_lz4_config(struct super_block *sb,
+				  struct erofs_super_block *dsb,
+				  struct z_erofs_lz4_cfgs *lz4, int len)
+{
+	if (lz4 || dsb->u1.lz4_max_distance) {
+		erofs_err(sb, "lz4 algorithm isn't enabled");
+		return -EINVAL;
+	}
+	return 0;
+}
+#endif	/* !CONFIG_EROFS_FS_ZIP */
+
+#ifdef CONFIG_EROFS_FS_ZIP_LZMA
+int z_erofs_lzma_init(void);
+void z_erofs_lzma_exit(void);
+int z_erofs_load_lzma_config(struct super_block *sb,
+			     struct erofs_super_block *dsb,
+			     struct z_erofs_lzma_cfgs *lzma, int size);
+#else
+static inline int z_erofs_lzma_init(void) { return 0; }
+static inline int z_erofs_lzma_exit(void) { return 0; }
+static inline int z_erofs_load_lzma_config(struct super_block *sb,
+			     struct erofs_super_block *dsb,
+			     struct z_erofs_lzma_cfgs *lzma, int size) {
+	if (lzma) {
+		erofs_err(sb, "lzma algorithm isn't enabled");
+		return -EINVAL;
+	}
+	return 0;
+}
+#endif	/* !CONFIG_EROFS_FS_ZIP */
+
+/* flags for erofs_fscache_register_cookie() */
+#define EROFS_REG_COOKIE_NEED_INODE	1
+#define EROFS_REG_COOKIE_NEED_NOEXIST	2
+
+/* fscache.c */
+#ifdef CONFIG_EROFS_FS_ONDEMAND
+int erofs_fscache_register_fs(struct super_block *sb);
+void erofs_fscache_unregister_fs(struct super_block *sb);
+
+struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
+						    char *name,
+						    unsigned int flags);
+void erofs_fscache_unregister_cookie(struct erofs_fscache *fscache);
+
+extern const struct address_space_operations erofs_fscache_access_aops;
+#else
+static inline int erofs_fscache_register_fs(struct super_block *sb)
+{
+	return -EOPNOTSUPP;
+}
+static inline void erofs_fscache_unregister_fs(struct super_block *sb) {}
+
+static inline
+struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
+						     char *name,
+						     unsigned int flags)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void erofs_fscache_unregister_cookie(struct erofs_fscache *fscache)
+{
+}
+#endif
+
+#define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
+
+#endif	/* __EROFS_INTERNAL_H */