linux/fs/erofs/internal.h
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00

437 lines
12 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://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
__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_fs_context {
#ifdef CONFIG_EROFS_FS_ZIP
/* current strategy of how to use managed cache */
unsigned char cache_strategy;
/* threshold for decompression synchronously */
unsigned int max_sync_decompress_pages;
#endif
unsigned int mount_opt;
};
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;
/* managed XArray arranged in physical block number */
struct xarray managed_pslots;
unsigned int shrinker_run_no;
/* 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 feature_compat;
u32 feature_incompat;
struct erofs_fs_context ctx; /* options */
};
#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 clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
#define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option)
#define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option)
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 */
/* 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 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_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;
#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_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);
}
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;
/*
* 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 */
struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
/* 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, 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);
#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);
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 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 */