erofs: move erofs out of staging

EROFS filesystem has been merged into linux-staging for a year.

EROFS is designed to be a better solution of saving extra storage
space with guaranteed end-to-end performance for read-only files
with the help of reduced metadata, fixed-sized output compression
and decompression inplace technologies.

In the past year, EROFS was greatly improved by many people as
a staging driver, self-tested, betaed by a large number of our
internal users, successfully applied to almost all in-service
HUAWEI smartphones as the part of EMUI 9.1 and proven to be stable
enough to be moved out of staging.

EROFS is a self-contained filesystem driver. Although there are
still some TODOs to be more generic, we have a dedicated team
actively keeping on working on EROFS in order to make it better
with the evolution of Linux kernel as the other in-kernel filesystems.

As Pavel suggested, it's better to do as one commit since git
can do moves and all histories will be saved in this way.

Let's promote it from staging and enhance it more actively as
a "real" part of kernel for more wider scenarios!

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Pavel Machek <pavel@denx.de>
Cc: David Sterba <dsterba@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J . Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Fang Wei <fangwei1@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190822213659.5501-1-hsiangkao@aol.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 553 insertions, 0 deletions

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
new file mode 100644
index 000000000000..620b73fcc416
--- /dev/null
+++ b/fs/erofs/internal.h
@@ -0,0 +1,553 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ */
+#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 "erofs_fs.h"
+
+/* redefine pr_fmt "erofs: " */
+#undef pr_fmt
+#define pr_fmt(fmt) "erofs: " fmt
+
+#define errln(x, ...)   pr_err(x "\n", ##__VA_ARGS__)
+#define infoln(x, ...)  pr_info(x "\n", ##__VA_ARGS__)
+#ifdef CONFIG_EROFS_FS_DEBUG
+#define debugln(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
+#define DBG_BUGON               BUG_ON
+#else
+#define debugln(x, ...)         ((void)0)
+#define DBG_BUGON(x)            ((void)(x))
+#endif	/* !CONFIG_EROFS_FS_DEBUG */
+
+enum {
+	FAULT_KMALLOC,
+	FAULT_READ_IO,
+	FAULT_MAX,
+};
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+extern const char *erofs_fault_name[FAULT_MAX];
+#define IS_FAULT_SET(fi, type) ((fi)->inject_type & (1 << (type)))
+
+struct erofs_fault_info {
+	atomic_t inject_ops;
+	unsigned int inject_rate;
+	unsigned int inject_type;
+};
+#endif	/* CONFIG_EROFS_FAULT_INJECTION */
+
+/* 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_sb_info {
+#ifdef CONFIG_EROFS_FS_ZIP
+	/* list for all registered superblocks, mainly for shrinker */
+	struct list_head list;
+	struct mutex umount_mutex;
+
+	/* the dedicated workstation for compression */
+	struct radix_tree_root workstn_tree;
+
+	/* threshold for decompression synchronously */
+	unsigned int max_sync_decompress_pages;
+
+	unsigned int shrinker_run_no;
+
+	/* current strategy of how to use managed cache */
+	unsigned char cache_strategy;
+
+	/* pseudo inode to manage cached pages */
+	struct inode *managed_cache;
+#endif	/* CONFIG_EROFS_FS_ZIP */
+	u32 blocks;
+	u32 meta_blkaddr;
+#ifdef CONFIG_EROFS_FS_XATTR
+	u32 xattr_blkaddr;
+#endif
+
+	/* inode slot unit size in bit shift */
+	unsigned char islotbits;
+
+	u32 build_time_nsec;
+	u64 build_time;
+
+	/* what we really care is nid, rather than ino.. */
+	erofs_nid_t root_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 requirements;
+
+	unsigned int mount_opt;
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+	struct erofs_fault_info fault_info;	/* For fault injection */
+#endif
+};
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+#define erofs_show_injection_info(type)					\
+	infoln("inject %s in %s of %pS", erofs_fault_name[type],        \
+		__func__, __builtin_return_address(0))
+
+static inline bool time_to_inject(struct erofs_sb_info *sbi, int type)
+{
+	struct erofs_fault_info *ffi = &sbi->fault_info;
+
+	if (!ffi->inject_rate)
+		return false;
+
+	if (!IS_FAULT_SET(ffi, type))
+		return false;
+
+	atomic_inc(&ffi->inject_ops);
+	if (atomic_read(&ffi->inject_ops) >= ffi->inject_rate) {
+		atomic_set(&ffi->inject_ops, 0);
+		return true;
+	}
+	return false;
+}
+#else
+static inline bool time_to_inject(struct erofs_sb_info *sbi, int type)
+{
+	return false;
+}
+
+static inline void erofs_show_injection_info(int type)
+{
+}
+#endif	/* !CONFIG_EROFS_FAULT_INJECTION */
+
+static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
+					size_t size, gfp_t flags)
+{
+	if (time_to_inject(sbi, FAULT_KMALLOC)) {
+		erofs_show_injection_info(FAULT_KMALLOC);
+		return NULL;
+	}
+	return kmalloc(size, flags);
+}
+
+#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_FAULT_INJECTION	0x00000040
+
+#define clear_opt(sbi, option)	((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
+#define set_opt(sbi, option)	((sbi)->mount_opt |= EROFS_MOUNT_##option)
+#define test_opt(sbi, option)	((sbi)->mount_opt & EROFS_MOUNT_##option)
+
+#ifdef CONFIG_EROFS_FS_ZIP
+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;
+};
+
+#if defined(CONFIG_SMP)
+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);
+}
+#else
+static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
+						 int val)
+{
+	preempt_disable();
+	/* no need to spin on UP platforms, let's just disable preemption. */
+	if (val != atomic_read(&grp->refcount)) {
+		preempt_enable();
+		return false;
+	}
+	return true;
+}
+
+static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
+					    int orig_val)
+{
+	preempt_enable();
+}
+
+static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
+{
+	int v = atomic_read(&grp->refcount);
+
+	/* workgroup is never freezed on uniprocessor systems */
+	DBG_BUGON(v == EROFS_LOCKED_MAGIC);
+	return v;
+}
+#endif	/* !CONFIG_SMP */
+
+/* hard limit of pages per compressed cluster */
+#define Z_EROFS_CLUSTER_MAX_PAGES       (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
+#define EROFS_PCPUBUF_NR_PAGES          Z_EROFS_CLUSTER_MAX_PAGES
+#else
+#define EROFS_PCPUBUF_NR_PAGES          0
+#endif	/* !CONFIG_EROFS_FS_ZIP */
+
+/* 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
+
+#define EROFS_IO_MAX_RETRIES_NOFAIL     5
+
+#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)
+
+static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
+{
+	return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
+}
+
+/* atomic flag definitions */
+#define EROFS_V_EA_INITED_BIT	0
+#define EROFS_V_Z_INITED_BIT	1
+
+/* bitlock definitions (arranged in reverse order) */
+#define EROFS_V_BL_XATTR_BIT	(BITS_PER_LONG - 1)
+#define EROFS_V_BL_Z_BIT	(BITS_PER_LONG - 2)
+
+struct erofs_vnode {
+	erofs_nid_t nid;
+
+	/* atomic flags (including bitlocks) */
+	unsigned long flags;
+
+	unsigned char datamode;
+	unsigned char inode_isize;
+	unsigned short xattr_isize;
+
+	unsigned int xattr_shared_count;
+	unsigned int *xattr_shared_xattrs;
+
+	union {
+		erofs_blk_t raw_blkaddr;
+#ifdef CONFIG_EROFS_FS_ZIP
+		struct {
+			unsigned short z_advise;
+			unsigned char  z_algorithmtype[2];
+			unsigned char  z_logical_clusterbits;
+			unsigned char  z_physical_clusterbits[2];
+		};
+#endif	/* CONFIG_EROFS_FS_ZIP */
+	};
+	/* the corresponding vfs inode */
+	struct inode vfs_inode;
+};
+
+#define EROFS_V(ptr)	\
+	container_of(ptr, struct erofs_vnode, vfs_inode)
+
+#define __inode_advise(x, bit, bits) \
+	(((x) >> (bit)) & ((1 << (bits)) - 1))
+
+#define __inode_version(advise)	\
+	__inode_advise(advise, EROFS_I_VERSION_BIT,	\
+		EROFS_I_VERSION_BITS)
+
+#define __inode_data_mapping(advise)	\
+	__inode_advise(advise, EROFS_I_DATA_MAPPING_BIT,\
+		EROFS_I_DATA_MAPPING_BITS)
+
+static inline unsigned long inode_datablocks(struct inode *inode)
+{
+	/* since i_size cannot be changed */
+	return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+}
+
+static inline bool is_inode_layout_compression(struct inode *inode)
+{
+	return erofs_inode_is_data_compressed(EROFS_V(inode)->datamode);
+}
+
+static inline bool is_inode_flat_inline(struct inode *inode)
+{
+	return EROFS_V(inode)->datamode == EROFS_INODE_FLAT_INLINE;
+}
+
+extern const struct super_operations erofs_sops;
+
+extern const struct address_space_operations erofs_raw_access_aops;
+#ifdef CONFIG_EROFS_FS_ZIP
+extern const struct address_space_operations z_erofs_vle_normalaccess_aops;
+#endif
+
+/*
+ * Logical to physical block mapping, used by erofs_map_blocks()
+ *
+ * Different with other file systems, it is used for 2 access modes:
+ *
+ * 1) RAW access mode:
+ *
+ * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
+ * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
+ *
+ * Note that m_lblk in the RAW access mode refers to the number of
+ * the compressed ondisk block rather than the uncompressed
+ * in-memory block for the compressed file.
+ *
+ * m_pofs equals to m_lofs except for the inline data page.
+ *
+ * 2) Normal access mode:
+ *
+ * If the inode is not compressed, it has no difference with
+ * the RAW access mode. However, if the inode is compressed,
+ * users should pass a valid (m_lblk, m_lofs) pair, and get
+ * the needed m_pblk, m_pofs, m_len to get the compressed data
+ * and the updated m_lblk, m_lofs which indicates the start
+ * of the corresponding uncompressed data in the file.
+ */
+enum {
+	BH_Zipped = BH_PrivateStart,
+	BH_FullMapped,
+};
+
+/* 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 has been compressed */
+#define EROFS_MAP_ZIPPED	(1 << BH_Zipped)
+/* The length of extent is full */
+#define EROFS_MAP_FULL_MAPPED	(1 << BH_FullMapped)
+
+struct erofs_map_blocks {
+	erofs_off_t m_pa, m_la;
+	u64 m_plen, m_llen;
+
+	unsigned int m_flags;
+
+	struct page *mpage;
+};
+
+/* Flags used by erofs_map_blocks() */
+#define EROFS_GET_BLOCKS_RAW    0x0001
+
+/* zmap.c */
+#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 */
+
+/* data.c */
+static inline struct bio *erofs_grab_bio(struct super_block *sb,
+					 erofs_blk_t blkaddr,
+					 unsigned int nr_pages,
+					 void *bi_private, bio_end_io_t endio,
+					 bool nofail)
+{
+	const gfp_t gfp = GFP_NOIO;
+	struct bio *bio;
+
+	do {
+		if (nr_pages == 1) {
+			bio = bio_alloc(gfp | (nofail ? __GFP_NOFAIL : 0), 1);
+			if (unlikely(!bio)) {
+				DBG_BUGON(nofail);
+				return ERR_PTR(-ENOMEM);
+			}
+			break;
+		}
+		bio = bio_alloc(gfp, nr_pages);
+		nr_pages /= 2;
+	} while (unlikely(!bio));
+
+	bio->bi_end_io = endio;
+	bio_set_dev(bio, sb->s_bdev);
+	bio->bi_iter.bi_sector = (sector_t)blkaddr << LOG_SECTORS_PER_BLOCK;
+	bio->bi_private = bi_private;
+	return bio;
+}
+
+static inline void __submit_bio(struct bio *bio, unsigned int op,
+				unsigned int op_flags)
+{
+	bio_set_op_attrs(bio, op, op_flags);
+	submit_bio(bio);
+}
+
+struct page *__erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr,
+				   bool prio, bool nofail);
+
+static inline struct page *erofs_get_meta_page(struct super_block *sb,
+	erofs_blk_t blkaddr, bool prio)
+{
+	return __erofs_get_meta_page(sb, blkaddr, prio, false);
+}
+
+int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
+
+static inline struct page *erofs_get_inline_page(struct inode *inode,
+						 erofs_blk_t blkaddr)
+{
+	return erofs_get_meta_page(inode->i_sb, blkaddr,
+				   S_ISDIR(inode->i_mode));
+}
+
+/* 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;
+
+static inline void set_inode_fast_symlink(struct inode *inode)
+{
+	inode->i_op = &erofs_fast_symlink_iops;
+}
+
+static inline bool is_inode_fast_symlink(struct inode *inode)
+{
+	return inode->i_op == &erofs_fast_symlink_iops;
+}
+
+struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
+int erofs_getattr(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, struct qstr *name,
+		erofs_nid_t *nid, unsigned int *d_type);
+
+/* dir.c */
+extern const struct file_operations erofs_dir_fops;
+
+/* utils.c / zdata.c */
+struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp, bool nofail);
+
+#if (EROFS_PCPUBUF_NR_PAGES > 0)
+void *erofs_get_pcpubuf(unsigned int pagenr);
+#define erofs_put_pcpubuf(buf) do { \
+	(void)&(buf);	\
+	preempt_enable();	\
+} while (0)
+#else
+static inline void *erofs_get_pcpubuf(unsigned int pagenr)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+#define erofs_put_pcpubuf(buf) do {} while (0)
+#endif
+
+#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, bool *tag);
+int erofs_register_workgroup(struct super_block *sb,
+			     struct erofs_workgroup *grp, bool tag);
+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 address_space *mapping,
+				  struct page *page);
+#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) {}
+#endif	/* !CONFIG_EROFS_FS_ZIP */
+
+#define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
+
+#endif	/* __EROFS_INTERNAL_H */
+