1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  linux/fs/hpfs/hpfs_fn.h
4  *
5  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6  *
7  *  function headers
8  */
9 
10 //#define DBG
11 //#define DEBUG_LOCKS
12 #ifdef pr_fmt
13 #undef pr_fmt
14 #endif
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/mutex.h>
19 #include <linux/pagemap.h>
20 #include <linux/buffer_head.h>
21 #include <linux/slab.h>
22 #include <linux/sched/signal.h>
23 #include <linux/blkdev.h>
24 #include <asm/unaligned.h>
25 
26 #include "hpfs.h"
27 
28 #define EIOERROR  EIO
29 #define EFSERROR  EUCLEAN
30 
31 #define ANODE_ALLOC_FWD	512
32 #define FNODE_ALLOC_FWD	0
33 #define ALLOC_FWD_MIN	16
34 #define ALLOC_FWD_MAX	128
35 #define ALLOC_M		1
36 #define FNODE_RD_AHEAD	16
37 #define ANODE_RD_AHEAD	0
38 #define DNODE_RD_AHEAD	72
39 #define COUNT_RD_AHEAD	62
40 
41 #define FREE_DNODES_ADD	58
42 #define FREE_DNODES_DEL	29
43 
44 #define CHKCOND(x,y) if (!(x)) printk y
45 
46 struct hpfs_inode_info {
47 	loff_t mmu_private;
48 	ino_t i_parent_dir;	/* (directories) gives fnode of parent dir */
49 	unsigned i_dno;		/* (directories) root dnode */
50 	unsigned i_dpos;	/* (directories) temp for readdir */
51 	unsigned i_dsubdno;	/* (directories) temp for readdir */
52 	unsigned i_file_sec;	/* (files) minimalist cache of alloc info */
53 	unsigned i_disk_sec;	/* (files) minimalist cache of alloc info */
54 	unsigned i_n_secs;	/* (files) minimalist cache of alloc info */
55 	unsigned i_ea_size;	/* size of extended attributes */
56 	unsigned i_ea_mode : 1;	/* file's permission is stored in ea */
57 	unsigned i_ea_uid : 1;	/* file's uid is stored in ea */
58 	unsigned i_ea_gid : 1;	/* file's gid is stored in ea */
59 	unsigned i_dirty : 1;
60 	loff_t **i_rddir_off;
61 	struct inode vfs_inode;
62 };
63 
64 struct hpfs_sb_info {
65 	struct mutex hpfs_mutex;	/* global hpfs lock */
66 	ino_t sb_root;			/* inode number of root dir */
67 	unsigned sb_fs_size;		/* file system size, sectors */
68 	unsigned sb_bitmaps;		/* sector number of bitmap list */
69 	unsigned sb_dirband_start;	/* directory band start sector */
70 	unsigned sb_dirband_size;	/* directory band size, dnodes */
71 	unsigned sb_dmap;		/* sector number of dnode bit map */
72 	unsigned sb_n_free;		/* free blocks for statfs, or -1 */
73 	unsigned sb_n_free_dnodes;	/* free dnodes for statfs, or -1 */
74 	kuid_t sb_uid;			/* uid from mount options */
75 	kgid_t sb_gid;			/* gid from mount options */
76 	umode_t sb_mode;		/* mode from mount options */
77 	unsigned sb_eas : 2;		/* eas: 0-ignore, 1-ro, 2-rw */
78 	unsigned sb_err : 2;		/* on errs: 0-cont, 1-ro, 2-panic */
79 	unsigned sb_chk : 2;		/* checks: 0-no, 1-normal, 2-strict */
80 	unsigned sb_lowercase : 1;	/* downcase filenames hackery */
81 	unsigned sb_was_error : 1;	/* there was an error, set dirty flag */
82 	unsigned sb_chkdsk : 2;		/* chkdsk: 0-no, 1-on errs, 2-allways */
83 	unsigned char *sb_cp_table;	/* code page tables: */
84 					/* 	128 bytes uppercasing table & */
85 					/*	128 bytes lowercasing table */
86 	__le32 *sb_bmp_dir;		/* main bitmap directory */
87 	unsigned sb_c_bitmap;		/* current bitmap */
88 	unsigned sb_max_fwd_alloc;	/* max forwad allocation */
89 	int sb_timeshift;
90 	struct rcu_head rcu;
91 
92 	unsigned n_hotfixes;
93 	secno hotfix_from[256];
94 	secno hotfix_to[256];
95 };
96 
97 /* Four 512-byte buffers and the 2k block obtained by concatenating them */
98 
99 struct quad_buffer_head {
100 	struct buffer_head *bh[4];
101 	void *data;
102 };
103 
104 /* The b-tree down pointer from a dir entry */
105 
de_down_pointer(struct hpfs_dirent * de)106 static inline dnode_secno de_down_pointer (struct hpfs_dirent *de)
107 {
108   CHKCOND(de->down,("HPFS: de_down_pointer: !de->down\n"));
109   return le32_to_cpu(*(__le32 *) ((void *) de + le16_to_cpu(de->length) - 4));
110 }
111 
112 /* The first dir entry in a dnode */
113 
dnode_first_de(struct dnode * dnode)114 static inline struct hpfs_dirent *dnode_first_de (struct dnode *dnode)
115 {
116   return (void *) dnode->dirent;
117 }
118 
119 /* The end+1 of the dir entries */
120 
dnode_end_de(struct dnode * dnode)121 static inline struct hpfs_dirent *dnode_end_de (struct dnode *dnode)
122 {
123   CHKCOND(le32_to_cpu(dnode->first_free)>=0x14 && le32_to_cpu(dnode->first_free)<=0xa00,("HPFS: dnode_end_de: dnode->first_free = %x\n",(unsigned)le32_to_cpu(dnode->first_free)));
124   return (void *) dnode + le32_to_cpu(dnode->first_free);
125 }
126 
127 /* The dir entry after dir entry de */
128 
de_next_de(struct hpfs_dirent * de)129 static inline struct hpfs_dirent *de_next_de (struct hpfs_dirent *de)
130 {
131   CHKCOND(le16_to_cpu(de->length)>=0x20 && le16_to_cpu(de->length)<0x800,("HPFS: de_next_de: de->length = %x\n",(unsigned)le16_to_cpu(de->length)));
132   return (void *) de + le16_to_cpu(de->length);
133 }
134 
fnode_ea(struct fnode * fnode)135 static inline struct extended_attribute *fnode_ea(struct fnode *fnode)
136 {
137 	return (struct extended_attribute *)((char *)fnode + le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s));
138 }
139 
fnode_end_ea(struct fnode * fnode)140 static inline struct extended_attribute *fnode_end_ea(struct fnode *fnode)
141 {
142 	return (struct extended_attribute *)((char *)fnode + le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s));
143 }
144 
ea_valuelen(struct extended_attribute * ea)145 static unsigned ea_valuelen(struct extended_attribute *ea)
146 {
147 	return ea->valuelen_lo + 256 * ea->valuelen_hi;
148 }
149 
next_ea(struct extended_attribute * ea)150 static inline struct extended_attribute *next_ea(struct extended_attribute *ea)
151 {
152 	return (struct extended_attribute *)((char *)ea + 5 + ea->namelen + ea_valuelen(ea));
153 }
154 
ea_sec(struct extended_attribute * ea)155 static inline secno ea_sec(struct extended_attribute *ea)
156 {
157 	return le32_to_cpu(get_unaligned((__le32 *)((char *)ea + 9 + ea->namelen)));
158 }
159 
ea_len(struct extended_attribute * ea)160 static inline secno ea_len(struct extended_attribute *ea)
161 {
162 	return le32_to_cpu(get_unaligned((__le32 *)((char *)ea + 5 + ea->namelen)));
163 }
164 
ea_data(struct extended_attribute * ea)165 static inline char *ea_data(struct extended_attribute *ea)
166 {
167 	return (char *)((char *)ea + 5 + ea->namelen);
168 }
169 
de_size(int namelen,secno down_ptr)170 static inline unsigned de_size(int namelen, secno down_ptr)
171 {
172 	return ((0x1f + namelen + 3) & ~3) + (down_ptr ? 4 : 0);
173 }
174 
copy_de(struct hpfs_dirent * dst,struct hpfs_dirent * src)175 static inline void copy_de(struct hpfs_dirent *dst, struct hpfs_dirent *src)
176 {
177 	int a;
178 	int n;
179 	if (!dst || !src) return;
180 	a = dst->down;
181 	n = dst->not_8x3;
182 	memcpy((char *)dst + 2, (char *)src + 2, 28);
183 	dst->down = a;
184 	dst->not_8x3 = n;
185 }
186 
tstbits(__le32 * bmp,unsigned b,unsigned n)187 static inline unsigned tstbits(__le32 *bmp, unsigned b, unsigned n)
188 {
189 	int i;
190 	if ((b >= 0x4000) || (b + n - 1 >= 0x4000)) return n;
191 	if (!((le32_to_cpu(bmp[(b & 0x3fff) >> 5]) >> (b & 0x1f)) & 1)) return 1;
192 	for (i = 1; i < n; i++)
193 		if (!((le32_to_cpu(bmp[((b+i) & 0x3fff) >> 5]) >> ((b+i) & 0x1f)) & 1))
194 			return i + 1;
195 	return 0;
196 }
197 
198 /* alloc.c */
199 
200 int hpfs_chk_sectors(struct super_block *, secno, int, char *);
201 secno hpfs_alloc_sector(struct super_block *, secno, unsigned, int);
202 int hpfs_alloc_if_possible(struct super_block *, secno);
203 void hpfs_free_sectors(struct super_block *, secno, unsigned);
204 int hpfs_check_free_dnodes(struct super_block *, int);
205 void hpfs_free_dnode(struct super_block *, secno);
206 struct dnode *hpfs_alloc_dnode(struct super_block *, secno, dnode_secno *, struct quad_buffer_head *);
207 struct fnode *hpfs_alloc_fnode(struct super_block *, secno, fnode_secno *, struct buffer_head **);
208 struct anode *hpfs_alloc_anode(struct super_block *, secno, anode_secno *, struct buffer_head **);
209 int hpfs_trim_fs(struct super_block *, u64, u64, u64, unsigned *);
210 
211 /* anode.c */
212 
213 secno hpfs_bplus_lookup(struct super_block *, struct inode *, struct bplus_header *, unsigned, struct buffer_head *);
214 secno hpfs_add_sector_to_btree(struct super_block *, secno, int, unsigned);
215 void hpfs_remove_btree(struct super_block *, struct bplus_header *);
216 int hpfs_ea_read(struct super_block *, secno, int, unsigned, unsigned, char *);
217 int hpfs_ea_write(struct super_block *, secno, int, unsigned, unsigned, const char *);
218 void hpfs_ea_remove(struct super_block *, secno, int, unsigned);
219 void hpfs_truncate_btree(struct super_block *, secno, int, unsigned);
220 void hpfs_remove_fnode(struct super_block *, fnode_secno fno);
221 
222 /* buffer.c */
223 
224 secno hpfs_search_hotfix_map(struct super_block *s, secno sec);
225 unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n);
226 void hpfs_prefetch_sectors(struct super_block *, unsigned, int);
227 void *hpfs_map_sector(struct super_block *, unsigned, struct buffer_head **, int);
228 void *hpfs_get_sector(struct super_block *, unsigned, struct buffer_head **);
229 void *hpfs_map_4sectors(struct super_block *, unsigned, struct quad_buffer_head *, int);
230 void *hpfs_get_4sectors(struct super_block *, unsigned, struct quad_buffer_head *);
231 void hpfs_brelse4(struct quad_buffer_head *);
232 void hpfs_mark_4buffers_dirty(struct quad_buffer_head *);
233 
234 /* dentry.c */
235 
236 extern const struct dentry_operations hpfs_dentry_operations;
237 
238 /* dir.c */
239 
240 struct dentry *hpfs_lookup(struct inode *, struct dentry *, unsigned int);
241 extern const struct file_operations hpfs_dir_ops;
242 
243 /* dnode.c */
244 
245 int hpfs_add_pos(struct inode *, loff_t *);
246 void hpfs_del_pos(struct inode *, loff_t *);
247 struct hpfs_dirent *hpfs_add_de(struct super_block *, struct dnode *,
248 				const unsigned char *, unsigned, secno);
249 int hpfs_add_dirent(struct inode *, const unsigned char *, unsigned,
250 		    struct hpfs_dirent *);
251 int hpfs_remove_dirent(struct inode *, dnode_secno, struct hpfs_dirent *, struct quad_buffer_head *, int);
252 void hpfs_count_dnodes(struct super_block *, dnode_secno, int *, int *, int *);
253 dnode_secno hpfs_de_as_down_as_possible(struct super_block *, dnode_secno dno);
254 struct hpfs_dirent *map_pos_dirent(struct inode *, loff_t *, struct quad_buffer_head *);
255 struct hpfs_dirent *map_dirent(struct inode *, dnode_secno,
256 			       const unsigned char *, unsigned, dnode_secno *,
257 			       struct quad_buffer_head *);
258 void hpfs_remove_dtree(struct super_block *, dnode_secno);
259 struct hpfs_dirent *map_fnode_dirent(struct super_block *, fnode_secno, struct fnode *, struct quad_buffer_head *);
260 
261 /* ea.c */
262 
263 void hpfs_ea_ext_remove(struct super_block *, secno, int, unsigned);
264 int hpfs_read_ea(struct super_block *, struct fnode *, char *, char *, int);
265 char *hpfs_get_ea(struct super_block *, struct fnode *, char *, int *);
266 void hpfs_set_ea(struct inode *, struct fnode *, const char *,
267 		 const char *, int);
268 
269 /* file.c */
270 
271 int hpfs_file_fsync(struct file *, loff_t, loff_t, int);
272 void hpfs_truncate(struct inode *);
273 extern const struct file_operations hpfs_file_ops;
274 extern const struct inode_operations hpfs_file_iops;
275 extern const struct address_space_operations hpfs_aops;
276 
277 /* inode.c */
278 
279 void hpfs_init_inode(struct inode *);
280 void hpfs_read_inode(struct inode *);
281 void hpfs_write_inode(struct inode *);
282 void hpfs_write_inode_nolock(struct inode *);
283 int hpfs_setattr(struct dentry *, struct iattr *);
284 void hpfs_write_if_changed(struct inode *);
285 void hpfs_evict_inode(struct inode *);
286 
287 /* map.c */
288 
289 __le32 *hpfs_map_dnode_bitmap(struct super_block *, struct quad_buffer_head *);
290 __le32 *hpfs_map_bitmap(struct super_block *, unsigned, struct quad_buffer_head *, char *);
291 void hpfs_prefetch_bitmap(struct super_block *, unsigned);
292 unsigned char *hpfs_load_code_page(struct super_block *, secno);
293 __le32 *hpfs_load_bitmap_directory(struct super_block *, secno bmp);
294 void hpfs_load_hotfix_map(struct super_block *s, struct hpfs_spare_block *spareblock);
295 struct fnode *hpfs_map_fnode(struct super_block *s, ino_t, struct buffer_head **);
296 struct anode *hpfs_map_anode(struct super_block *s, anode_secno, struct buffer_head **);
297 struct dnode *hpfs_map_dnode(struct super_block *s, dnode_secno, struct quad_buffer_head *);
298 dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino);
299 
300 /* name.c */
301 
302 unsigned char hpfs_upcase(unsigned char *, unsigned char);
303 int hpfs_chk_name(const unsigned char *, unsigned *);
304 unsigned char *hpfs_translate_name(struct super_block *, unsigned char *, unsigned, int, int);
305 int hpfs_compare_names(struct super_block *, const unsigned char *, unsigned,
306 		       const unsigned char *, unsigned, int);
307 int hpfs_is_name_long(const unsigned char *, unsigned);
308 void hpfs_adjust_length(const unsigned char *, unsigned *);
309 
310 /* namei.c */
311 
312 extern const struct inode_operations hpfs_dir_iops;
313 extern const struct address_space_operations hpfs_symlink_aops;
314 
hpfs_i(struct inode * inode)315 static inline struct hpfs_inode_info *hpfs_i(struct inode *inode)
316 {
317 	return container_of(inode, struct hpfs_inode_info, vfs_inode);
318 }
319 
hpfs_sb(struct super_block * sb)320 static inline struct hpfs_sb_info *hpfs_sb(struct super_block *sb)
321 {
322 	return sb->s_fs_info;
323 }
324 
325 /* super.c */
326 
327 __printf(2, 3)
328 void hpfs_error(struct super_block *, const char *, ...);
329 int hpfs_stop_cycles(struct super_block *, int, int *, int *, char *);
330 unsigned hpfs_get_free_dnodes(struct super_block *);
331 long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg);
332 
333 /*
334  * local time (HPFS) to GMT (Unix)
335  */
336 
local_to_gmt(struct super_block * s,time32_t t)337 static inline time64_t local_to_gmt(struct super_block *s, time32_t t)
338 {
339 	extern struct timezone sys_tz;
340 	return t + sys_tz.tz_minuteswest * 60 + hpfs_sb(s)->sb_timeshift;
341 }
342 
gmt_to_local(struct super_block * s,time64_t t)343 static inline time32_t gmt_to_local(struct super_block *s, time64_t t)
344 {
345 	extern struct timezone sys_tz;
346 	t = t - sys_tz.tz_minuteswest * 60 - hpfs_sb(s)->sb_timeshift;
347 
348 	return clamp_t(time64_t, t, 0, U32_MAX);
349 }
350 
local_get_seconds(struct super_block * s)351 static inline time32_t local_get_seconds(struct super_block *s)
352 {
353 	return gmt_to_local(s, ktime_get_real_seconds());
354 }
355 
356 /*
357  * Locking:
358  *
359  * hpfs_lock() locks the whole filesystem. It must be taken
360  * on any method called by the VFS.
361  *
362  * We don't do any per-file locking anymore, it is hard to
363  * review and HPFS is not performance-sensitive anyway.
364  */
hpfs_lock(struct super_block * s)365 static inline void hpfs_lock(struct super_block *s)
366 {
367 	struct hpfs_sb_info *sbi = hpfs_sb(s);
368 	mutex_lock(&sbi->hpfs_mutex);
369 }
370 
hpfs_unlock(struct super_block * s)371 static inline void hpfs_unlock(struct super_block *s)
372 {
373 	struct hpfs_sb_info *sbi = hpfs_sb(s);
374 	mutex_unlock(&sbi->hpfs_mutex);
375 }
376 
hpfs_lock_assert(struct super_block * s)377 static inline void hpfs_lock_assert(struct super_block *s)
378 {
379 	struct hpfs_sb_info *sbi = hpfs_sb(s);
380 	WARN_ON(!mutex_is_locked(&sbi->hpfs_mutex));
381 }
382