1 #ifndef FS_H
2 #define FS_H
3
4 #include <linux/list.h>
5 #include <stddef.h>
6 #include <stdbool.h>
7 #include <string.h>
8 #include <com32.h>
9 #include <stdio.h>
10 #include <sys/dirent.h>
11 #include <dprintf.h>
12 #include "core.h"
13 #include "disk.h"
14
15 /*
16 * Maximum number of open files.
17 */
18 #define MAX_OPEN_LG2 7
19 #define MAX_OPEN (1 << MAX_OPEN_LG2)
20
21 #define FILENAME_MAX_LG2 8
22 #define FILENAME_MAX (1 << FILENAME_MAX_LG2)
23
24 #define CURRENTDIR_MAX FILENAME_MAX
25
26 #define BLOCK_SIZE(fs) ((fs)->block_size)
27 #define BLOCK_SHIFT(fs) ((fs)->block_shift)
28 #define SECTOR_SIZE(fs) ((fs)->sector_size)
29 #define SECTOR_SHIFT(fs) ((fs)->sector_shift)
30
31 struct fs_info {
32 const struct fs_ops *fs_ops;
33 struct device *fs_dev;
34 void *fs_info; /* The fs-specific information */
35 int sector_shift, sector_size;
36 int block_shift, block_size;
37 struct inode *root, *cwd; /* Root and current directories */
38 char cwd_name[CURRENTDIR_MAX]; /* Current directory by name */
39 };
40
41 extern struct fs_info *this_fs;
42
43 struct dirent; /* Directory entry structure */
44 struct file;
45 enum fs_flags {
46 FS_NODEV = 1 << 0,
47 FS_USEMEM = 1 << 1, /* If we need a malloc routine, set it */
48 FS_THISIND = 1 << 2, /* Set cwd based on config file location */
49 };
50
51 struct fs_ops {
52 /* in fact, we use fs_ops structure to find the right fs */
53 const char *fs_name;
54 enum fs_flags fs_flags;
55
56 int (*fs_init)(struct fs_info *);
57 void (*searchdir)(const char *, int, struct file *);
58 uint32_t (*getfssec)(struct file *, char *, int, bool *);
59 void (*close_file)(struct file *);
60 void (*mangle_name)(char *, const char *);
61 size_t (*realpath)(struct fs_info *, char *, const char *, size_t);
62 int (*chdir)(struct fs_info *, const char *);
63 int (*chdir_start)(void);
64 int (*open_config)(struct com32_filedata *);
65
66 struct inode * (*iget_root)(struct fs_info *);
67 struct inode * (*iget)(const char *, struct inode *);
68 int (*readlink)(struct inode *, char *);
69
70 /* the _dir_ stuff */
71 int (*readdir)(struct file *, struct dirent *);
72
73 int (*next_extent)(struct inode *, uint32_t);
74
75 int (*copy_super)(void *buf);
76
77 char * (*fs_uuid)(struct fs_info *);
78
79 };
80
81 /*
82 * Extent structure: contains the mapping of some chunk of a file
83 * that is contiguous on disk.
84 */
85 struct extent {
86 sector_t pstart; /* Physical start sector */
87 uint32_t lstart; /* Logical start sector */
88 uint32_t len; /* Number of contiguous sectors */
89 };
90
91 /* Special sector numbers used for struct extent.pstart */
92 #define EXTENT_ZERO ((sector_t)-1) /* All-zero extent */
93 #define EXTENT_VOID ((sector_t)-2) /* Invalid information */
94
95 #define EXTENT_SPECIAL(x) ((x) >= EXTENT_VOID)
96
97 /*
98 * The inode structure, including the detail file information
99 */
100 struct inode {
101 struct fs_info *fs; /* The filesystem this inode is associated with */
102 struct inode *parent; /* Parent directory, if any */
103 const char *name; /* Name, valid for generic path search only */
104 int refcnt;
105 int mode; /* FILE , DIR or SYMLINK */
106 uint64_t size;
107 uint64_t blocks; /* How many blocks the file take */
108 uint64_t ino; /* Inode number */
109 uint32_t atime; /* Access time */
110 uint32_t mtime; /* Modify time */
111 uint32_t ctime; /* Create time */
112 uint32_t dtime; /* Delete time */
113 uint32_t flags;
114 uint32_t file_acl;
115 struct extent this_extent, next_extent;
116 char pvt[0]; /* Private filesystem data */
117 };
118
119 struct file {
120 struct fs_info *fs;
121 uint32_t offset; /* for next read */
122 struct inode *inode; /* The file-specific information */
123 };
124
125 /*
126 * Struct device contains:
127 * the pointer points to the disk structure,
128 * the cache stuff.
129 */
130 struct cache;
131
132 struct device {
133 struct disk *disk;
134
135 /* the cache stuff */
136 uint8_t cache_init; /* cache initialized state */
137 char *cache_data;
138 struct cache *cache_head;
139 uint16_t cache_block_size;
140 uint16_t cache_entries;
141 uint32_t cache_size;
142 };
143
144 /*
145 * Our definition of "not whitespace"
146 */
not_whitespace(char c)147 static inline bool not_whitespace(char c)
148 {
149 return (unsigned char)c > ' ';
150 }
151
152 /*
153 * Inode allocator/deallocator
154 */
155 struct inode *alloc_inode(struct fs_info *fs, uint32_t ino, size_t data);
free_inode(struct inode * inode)156 static inline void free_inode(struct inode * inode)
157 {
158 free(inode);
159 }
160
get_inode(struct inode * inode)161 static inline struct inode *get_inode(struct inode *inode)
162 {
163 inode->refcnt++;
164 dprintf("get_inode %p name %s refcnt %d\n",
165 inode, inode->name, inode->refcnt);
166 return inode;
167 }
168
169 void put_inode(struct inode *inode);
170
malloc_error(char * obj)171 static inline void malloc_error(char *obj)
172 {
173 printf("Out of memory: can't allocate memory for %s\n", obj);
174 kaboom();
175 }
176
177 /*
178 * File handle conversion functions
179 */
180 extern struct file files[];
file_to_handle(struct file * file)181 static inline uint16_t file_to_handle(struct file *file)
182 {
183 return file ? (file - files)+1 : 0;
184 }
handle_to_file(uint16_t handle)185 static inline struct file *handle_to_file(uint16_t handle)
186 {
187 return handle ? &files[handle-1] : NULL;
188 }
189
190 struct path_entry {
191 struct list_head list;
192 const char *str;
193 };
194
195 extern struct list_head PATH;
196
197 extern struct path_entry *path_add(const char *str);
198
199 /* fs.c */
200 void fs_init(const struct fs_ops **ops, void *priv);
201 void pm_mangle_name(com32sys_t *);
202 void pm_searchdir(com32sys_t *);
203 void mangle_name(char *, const char *);
204 int searchdir(const char *name, int flags);
205 void _close_file(struct file *);
206 size_t pmapi_read_file(uint16_t *handle, void *buf, size_t sectors);
207 int open_file(const char *name, int flags, struct com32_filedata *filedata);
208 void pm_open_file(com32sys_t *);
209 void close_file(uint16_t handle);
210 void pm_close_file(com32sys_t *);
211 int open_config(void);
212 char *fs_uuid(void);
213
214 extern uint16_t SectorShift;
215
216 /* chdir.c */
217 void pm_realpath(com32sys_t *regs);
218 size_t realpath(char *dst, const char *src, size_t bufsize);
219 int chdir(const char *src);
220
221 /* readdir.c */
222 DIR *opendir(const char *pathname);
223 struct dirent *readdir(DIR *dir);
224 int closedir(DIR *dir);
225
226 /* getcwd.c */
227 char *core_getcwd(char *buf, size_t size);
228
229 /*
230 * Generic functions that filesystem drivers may choose to use
231 */
232
233 /* chdir.c */
234 int generic_chdir_start(void);
235
236 /* mangle.c */
237 void generic_mangle_name(char *, const char *);
238
239 /* loadconfig.c */
240 int search_dirs(struct com32_filedata *filedata,
241 const char *search_directores[], const char *filenames[],
242 char *realname);
243 int generic_open_config(struct com32_filedata *filedata);
244
245 /* close.c */
246 void generic_close_file(struct file *file);
247
248 /* getfssec.c */
249 uint32_t generic_getfssec(struct file *file, char *buf,
250 int sectors, bool *have_more);
251
252 /* nonextextent.c */
253 int no_next_extent(struct inode *, uint32_t);
254
255 #endif /* FS_H */
256