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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2017-2018 HUAWEI, Inc.
4 * http://www.huawei.com/
5 * Created by Gao Xiang <gaoxiang25@huawei.com>
6 */
7#ifndef __EROFS_INTERNAL_H
8#define __EROFS_INTERNAL_H
9
10#include <linux/fs.h>
11#include <linux/dcache.h>
12#include <linux/mm.h>
13#include <linux/pagemap.h>
14#include <linux/bio.h>
15#include <linux/buffer_head.h>
16#include <linux/magic.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19#include "erofs_fs.h"
20
21/* redefine pr_fmt "erofs: " */
22#undef pr_fmt
23#define pr_fmt(fmt) "erofs: " fmt
24
25__printf(3, 4) void _erofs_err(struct super_block *sb,
26 const char *function, const char *fmt, ...);
27#define erofs_err(sb, fmt, ...) \
28 _erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__)
29__printf(3, 4) void _erofs_info(struct super_block *sb,
30 const char *function, const char *fmt, ...);
31#define erofs_info(sb, fmt, ...) \
32 _erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__)
33#ifdef CONFIG_EROFS_FS_DEBUG
34#define erofs_dbg(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
35#define DBG_BUGON BUG_ON
36#else
37#define erofs_dbg(x, ...) ((void)0)
38#define DBG_BUGON(x) ((void)(x))
39#endif /* !CONFIG_EROFS_FS_DEBUG */
40
41/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
42#define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
43
44typedef u64 erofs_nid_t;
45typedef u64 erofs_off_t;
46/* data type for filesystem-wide blocks number */
47typedef u32 erofs_blk_t;
48
49struct erofs_sb_info {
50#ifdef CONFIG_EROFS_FS_ZIP
51 /* list for all registered superblocks, mainly for shrinker */
52 struct list_head list;
53 struct mutex umount_mutex;
54
55 /* the dedicated workstation for compression */
56 struct radix_tree_root workstn_tree;
57
58 /* threshold for decompression synchronously */
59 unsigned int max_sync_decompress_pages;
60
61 unsigned int shrinker_run_no;
62
63 /* current strategy of how to use managed cache */
64 unsigned char cache_strategy;
65
66 /* pseudo inode to manage cached pages */
67 struct inode *managed_cache;
68#endif /* CONFIG_EROFS_FS_ZIP */
69 u32 blocks;
70 u32 meta_blkaddr;
71#ifdef CONFIG_EROFS_FS_XATTR
72 u32 xattr_blkaddr;
73#endif
74
75 /* inode slot unit size in bit shift */
76 unsigned char islotbits;
77
78 u32 build_time_nsec;
79 u64 build_time;
80
81 /* what we really care is nid, rather than ino.. */
82 erofs_nid_t root_nid;
83 /* used for statfs, f_files - f_favail */
84 u64 inos;
85
86 u8 uuid[16]; /* 128-bit uuid for volume */
87 u8 volume_name[16]; /* volume name */
88 u32 feature_compat;
89 u32 feature_incompat;
90
91 unsigned int mount_opt;
92};
93
94#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
95#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
96
97/* Mount flags set via mount options or defaults */
98#define EROFS_MOUNT_XATTR_USER 0x00000010
99#define EROFS_MOUNT_POSIX_ACL 0x00000020
100
101#define clear_opt(sbi, option) ((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
102#define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option)
103#define test_opt(sbi, option) ((sbi)->mount_opt & EROFS_MOUNT_##option)
104
105#ifdef CONFIG_EROFS_FS_ZIP
106enum {
107 EROFS_ZIP_CACHE_DISABLED,
108 EROFS_ZIP_CACHE_READAHEAD,
109 EROFS_ZIP_CACHE_READAROUND
110};
111
112#define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL)
113
114/* basic unit of the workstation of a super_block */
115struct erofs_workgroup {
116 /* the workgroup index in the workstation */
117 pgoff_t index;
118
119 /* overall workgroup reference count */
120 atomic_t refcount;
121};
122
123#if defined(CONFIG_SMP)
124static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
125 int val)
126{
127 preempt_disable();
128 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
129 preempt_enable();
130 return false;
131 }
132 return true;
133}
134
135static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
136 int orig_val)
137{
138 /*
139 * other observers should notice all modifications
140 * in the freezing period.
141 */
142 smp_mb();
143 atomic_set(&grp->refcount, orig_val);
144 preempt_enable();
145}
146
147static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
148{
149 return atomic_cond_read_relaxed(&grp->refcount,
150 VAL != EROFS_LOCKED_MAGIC);
151}
152#else
153static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
154 int val)
155{
156 preempt_disable();
157 /* no need to spin on UP platforms, let's just disable preemption. */
158 if (val != atomic_read(&grp->refcount)) {
159 preempt_enable();
160 return false;
161 }
162 return true;
163}
164
165static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
166 int orig_val)
167{
168 preempt_enable();
169}
170
171static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
172{
173 int v = atomic_read(&grp->refcount);
174
175 /* workgroup is never freezed on uniprocessor systems */
176 DBG_BUGON(v == EROFS_LOCKED_MAGIC);
177 return v;
178}
179#endif /* !CONFIG_SMP */
180
181/* hard limit of pages per compressed cluster */
182#define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
183#define EROFS_PCPUBUF_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES
184#else
185#define EROFS_PCPUBUF_NR_PAGES 0
186#endif /* !CONFIG_EROFS_FS_ZIP */
187
188/* we strictly follow PAGE_SIZE and no buffer head yet */
189#define LOG_BLOCK_SIZE PAGE_SHIFT
190
191#undef LOG_SECTORS_PER_BLOCK
192#define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
193
194#undef SECTORS_PER_BLOCK
195#define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
196
197#define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
198
199#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
200#error erofs cannot be used in this platform
201#endif
202
203#define ROOT_NID(sb) ((sb)->root_nid)
204
205#define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
206#define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
207#define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
208
209static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
210{
211 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
212}
213
214/* atomic flag definitions */
215#define EROFS_I_EA_INITED_BIT 0
216#define EROFS_I_Z_INITED_BIT 1
217
218/* bitlock definitions (arranged in reverse order) */
219#define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1)
220#define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2)
221
222struct erofs_inode {
223 erofs_nid_t nid;
224
225 /* atomic flags (including bitlocks) */
226 unsigned long flags;
227
228 unsigned char datalayout;
229 unsigned char inode_isize;
230 unsigned short xattr_isize;
231
232 unsigned int xattr_shared_count;
233 unsigned int *xattr_shared_xattrs;
234
235 union {
236 erofs_blk_t raw_blkaddr;
237#ifdef CONFIG_EROFS_FS_ZIP
238 struct {
239 unsigned short z_advise;
240 unsigned char z_algorithmtype[2];
241 unsigned char z_logical_clusterbits;
242 unsigned char z_physical_clusterbits[2];
243 };
244#endif /* CONFIG_EROFS_FS_ZIP */
245 };
246 /* the corresponding vfs inode */
247 struct inode vfs_inode;
248};
249
250#define EROFS_I(ptr) \
251 container_of(ptr, struct erofs_inode, vfs_inode)
252
253static inline unsigned long erofs_inode_datablocks(struct inode *inode)
254{
255 /* since i_size cannot be changed */
256 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
257}
258
259static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
260 unsigned int bits)
261{
262
263 return (value >> bit) & ((1 << bits) - 1);
264}
265
266
267static inline unsigned int erofs_inode_version(unsigned int value)
268{
269 return erofs_bitrange(value, EROFS_I_VERSION_BIT,
270 EROFS_I_VERSION_BITS);
271}
272
273static inline unsigned int erofs_inode_datalayout(unsigned int value)
274{
275 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
276 EROFS_I_DATALAYOUT_BITS);
277}
278
279extern const struct super_operations erofs_sops;
280
281extern const struct address_space_operations erofs_raw_access_aops;
282extern const struct address_space_operations z_erofs_aops;
283
284/*
285 * Logical to physical block mapping, used by erofs_map_blocks()
286 *
287 * Different with other file systems, it is used for 2 access modes:
288 *
289 * 1) RAW access mode:
290 *
291 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
292 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
293 *
294 * Note that m_lblk in the RAW access mode refers to the number of
295 * the compressed ondisk block rather than the uncompressed
296 * in-memory block for the compressed file.
297 *
298 * m_pofs equals to m_lofs except for the inline data page.
299 *
300 * 2) Normal access mode:
301 *
302 * If the inode is not compressed, it has no difference with
303 * the RAW access mode. However, if the inode is compressed,
304 * users should pass a valid (m_lblk, m_lofs) pair, and get
305 * the needed m_pblk, m_pofs, m_len to get the compressed data
306 * and the updated m_lblk, m_lofs which indicates the start
307 * of the corresponding uncompressed data in the file.
308 */
309enum {
310 BH_Zipped = BH_PrivateStart,
311 BH_FullMapped,
312};
313
314/* Has a disk mapping */
315#define EROFS_MAP_MAPPED (1 << BH_Mapped)
316/* Located in metadata (could be copied from bd_inode) */
317#define EROFS_MAP_META (1 << BH_Meta)
318/* The extent has been compressed */
319#define EROFS_MAP_ZIPPED (1 << BH_Zipped)
320/* The length of extent is full */
321#define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
322
323struct erofs_map_blocks {
324 erofs_off_t m_pa, m_la;
325 u64 m_plen, m_llen;
326
327 unsigned int m_flags;
328
329 struct page *mpage;
330};
331
332/* Flags used by erofs_map_blocks() */
333#define EROFS_GET_BLOCKS_RAW 0x0001
334
335/* zmap.c */
336#ifdef CONFIG_EROFS_FS_ZIP
337int z_erofs_fill_inode(struct inode *inode);
338int z_erofs_map_blocks_iter(struct inode *inode,
339 struct erofs_map_blocks *map,
340 int flags);
341#else
342static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
343static inline int z_erofs_map_blocks_iter(struct inode *inode,
344 struct erofs_map_blocks *map,
345 int flags)
346{
347 return -EOPNOTSUPP;
348}
349#endif /* !CONFIG_EROFS_FS_ZIP */
350
351/* data.c */
352struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
353
354int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
355
356/* inode.c */
357static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
358{
359#if BITS_PER_LONG == 32
360 return (nid >> 32) ^ (nid & 0xffffffff);
361#else
362 return nid;
363#endif
364}
365
366extern const struct inode_operations erofs_generic_iops;
367extern const struct inode_operations erofs_symlink_iops;
368extern const struct inode_operations erofs_fast_symlink_iops;
369
370struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
371int erofs_getattr(const struct path *path, struct kstat *stat,
372 u32 request_mask, unsigned int query_flags);
373
374/* namei.c */
375extern const struct inode_operations erofs_dir_iops;
376
377int erofs_namei(struct inode *dir, struct qstr *name,
378 erofs_nid_t *nid, unsigned int *d_type);
379
380/* dir.c */
381extern const struct file_operations erofs_dir_fops;
382
383/* utils.c / zdata.c */
384struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
385
386#if (EROFS_PCPUBUF_NR_PAGES > 0)
387void *erofs_get_pcpubuf(unsigned int pagenr);
388#define erofs_put_pcpubuf(buf) do { \
389 (void)&(buf); \
390 preempt_enable(); \
391} while (0)
392#else
393static inline void *erofs_get_pcpubuf(unsigned int pagenr)
394{
395 return ERR_PTR(-EOPNOTSUPP);
396}
397
398#define erofs_put_pcpubuf(buf) do {} while (0)
399#endif
400
401#ifdef CONFIG_EROFS_FS_ZIP
402int erofs_workgroup_put(struct erofs_workgroup *grp);
403struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
404 pgoff_t index);
405int erofs_register_workgroup(struct super_block *sb,
406 struct erofs_workgroup *grp);
407void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
408void erofs_shrinker_register(struct super_block *sb);
409void erofs_shrinker_unregister(struct super_block *sb);
410int __init erofs_init_shrinker(void);
411void erofs_exit_shrinker(void);
412int __init z_erofs_init_zip_subsystem(void);
413void z_erofs_exit_zip_subsystem(void);
414int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
415 struct erofs_workgroup *egrp);
416int erofs_try_to_free_cached_page(struct address_space *mapping,
417 struct page *page);
418#else
419static inline void erofs_shrinker_register(struct super_block *sb) {}
420static inline void erofs_shrinker_unregister(struct super_block *sb) {}
421static inline int erofs_init_shrinker(void) { return 0; }
422static inline void erofs_exit_shrinker(void) {}
423static inline int z_erofs_init_zip_subsystem(void) { return 0; }
424static inline void z_erofs_exit_zip_subsystem(void) {}
425#endif /* !CONFIG_EROFS_FS_ZIP */
426
427#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
428
429#endif /* __EROFS_INTERNAL_H */
430