linux/fs/erofs/internal.h
Jeffle Xu 1442b02b66 erofs: implement fscache-based data read for non-inline layout
Implement the data plane of reading data from data blobs over fscache
for non-inline layout.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220425122143.56815-19-jefflexu@linux.alibaba.com
Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2022-05-18 00:11:20 +08:00

641 lines
18 KiB
C

/* 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;
char *fsid;
};
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;
};
/* 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_fscache {
struct fscache_cookie *cookie;
struct inode *inode;
};
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;
#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;
/* 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;
};
#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
};
#ifdef CONFIG_EROFS_FS_ZIP
#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 */
#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
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)
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);
}
#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(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 short 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;
erofs_off_t z_idataoff;
unsigned short z_idata_size;
};
#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 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 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,
};
/* 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)
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 pcluster */
#define EROFS_GET_BLOCKS_FINDTAIL 0x0008
enum {
Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
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, bool dir);
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 */
/* 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);
int erofs_fscache_register_cookie(struct super_block *sb,
struct erofs_fscache **fscache,
char *name, bool need_inode);
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 0;
}
static inline void erofs_fscache_unregister_fs(struct super_block *sb) {}
static inline int erofs_fscache_register_cookie(struct super_block *sb,
struct erofs_fscache **fscache,
char *name, bool need_inode)
{
return -EOPNOTSUPP;
}
static inline void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
{
}
#endif
#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
#endif /* __EROFS_INTERNAL_H */