1/* @title: Ext2 */
2#include <block/bcache.h>
3#include <block/block.h>
4#include <compiler.h>
5#include <errno.h>
6#include <fs/vfs.h>
7#include <mem/alloc.h>
8#include <stdint.h>
9#include <sync/spinlock.h>
10#include <types/types.h>
11
12/* TODO: move this flaming disaster into internal.h, and also, this file
13 * is going to all get modified BIG TIME when we get actual page cache stuff.
14 *
15 * If you are reading this for the sake of education, DON'T! */
16extern uint64_t PTRS_PER_BLOCK;
17
18#define EXT2_PRIO_DIRENT BIO_RQ_MEDIUM
19#define EXT2_PRIO_INODE BIO_RQ_MEDIUM
20#define EXT2_PRIO_DATA BIO_RQ_HIGH
21#define EXT2_PRIO_BITMAPS BIO_RQ_BACKGROUND
22#define EXT2_PRIO_SBLOCK BIO_RQ_LOW
23
24#define EXT2_NBLOCKS 15
25#define EXT2_SUPERBLOCK_OFFSET 1024
26#define EXT2_SIGNATURE_OFFSET 0x38
27#define EXT2_SIGNATURE 0xEF53
28#define EXT2_NAME_LEN 255
29#define EXT2_ROOT_INODE 2
30#define EXT2_S_IFSOCK 0xC000 // socket
31#define EXT2_S_IFLNK 0xA000 // symbolic link
32#define EXT2_S_IFREG 0x8000 // regular file
33#define EXT2_S_IFBLK 0x6000 // block device
34#define EXT2_S_IFDIR 0x4000 // directory
35#define EXT2_S_IFCHR 0x2000 // character device
36#define EXT2_S_IFIFO 0x1000 // FIFO
37#define EXT2_S_IFMT 0xF000 // mask to extract file type from i_mode
38#define EXT2_S_PERMS 0x0FFF // lower 12 bits: special + rwx bits
39#define EXT2_S_IRWXU 0x01C0 // owner permissions - ALL
40#define EXT2_S_IRWXG 0x0038 // group permissions - ALL
41#define EXT2_S_IRWXO 0x0007 // others permissions - ALL
42#define EXT2_S_PERMS_ONLY 0x01FF // rwx bits only
43
44#define EXT2_S_IRUSR 0x0100 // Owner can read
45#define EXT2_S_IWUSR 0x0080 // Owner can write
46#define EXT2_S_IXUSR 0x0040 // Owner can execute
47#define EXT2_S_IRGRP 0x0020 // Group can read
48#define EXT2_S_IWGRP 0x0010 // Group can write
49#define EXT2_S_IXGRP 0x0008 // Group can execute
50#define EXT2_S_IROTH 0x0004 // Others can read
51#define EXT2_S_IWOTH 0x0002 // Others can write
52#define EXT2_S_IXOTH 0x0001 // Others can execute
53
54#define EXT2_FT_UNKNOWN 0 // Unknown file type
55#define EXT2_FT_REG_FILE 1 // Regular file
56#define EXT2_FT_DIR 2 // Directory
57#define EXT2_FT_CHRDEV 3 // Character device
58#define EXT2_FT_BLKDEV 4 // Block device
59#define EXT2_FT_FIFO 5 // FIFO (named pipe)
60#define EXT2_FT_SOCK 6 // Unix domain socket
61#define EXT2_FT_SYMLINK 7 // Symbolic link
62#define EXT2_FT_MAX 8 // Number of defined file types
63
64// ext2 inode flags
65#define EXT2_SECRM_FL 0x00000001 // Secure deletion
66#define EXT2_UNRM_FL 0x00000002 // Undelete
67#define EXT2_COMPR_FL 0x00000004 // Compress file
68#define EXT2_SYNC_FL 0x00000008 // Synchronous updates
69#define EXT2_IMMUTABLE_FL 0x00000010 // Immutable file
70#define EXT2_APPEND_FL 0x00000020 // Writes only append
71#define EXT2_NODUMP_FL 0x00000040 // Don't include in backups
72#define EXT2_NOATIME_FL 0x00000080 // Don't update access time
73
74#define EXT2_DIRTY_FL 0x00000100 // Dirty (compress support)
75#define EXT2_COMPRBLK_FL 0x00000200 // One or more compressed clusters
76#define EXT2_NOCOMPR_FL 0x00000400 // Don't compress
77#define EXT2_ECOMPR_FL 0x00000800 // Compression error
78#define EXT2_IMAGIC_FL 0x00002000 // AFS directory
79#define EXT2_JOURNAL_DATA_FL 0x00004000 // Write data to journal (data=journal)
80
81#define EXT2_NOTAIL_FL 0x00008000 // File tail not merged (reiserfs)
82#define EXT2_DIRSYNC_FL 0x00010000 // Directory sync updates
83#define EXT2_TOPDIR_FL 0x00020000 // Top of directory hierarchy
84#define EXT2_HUGE_FILE_FL 0x00040000 // Set to each huge file
85#define EXT2_EXTENTS_FL 0x00080000 // Inode uses extents
86
87#define EXT2_EA_INODE_FL 0x00200000 // Inode stores extended attributes
88#define EXT2_INLINE_DATA_FL 0x10000000 // Data is stored inline in inode
89#define EXT2_PROJINHERIT_FL 0x20000000 // Project ID inheritance
90
91#define EXT2_RESERVED_FL 0x80000000 // Reserved for ext3/4
92
93// Useful masks
94#define EXT2_FL_USER_VISIBLE 0x000BDFFF // User-visible flags
95#define EXT2_FL_USER_MODIFIABLE \
96 (EXT2_FL_USER_VISIBLE & ~(EXT2_SECRM_FL | EXT2_UNRM_FL))
97
98#define MIN(x, y) ((x > y) ? y : x)
99
100#define MAKE_NOP_CALLBACK \
101 static bool nop_callback(struct ext2_fs *fs, struct ext2_dir_entry *entry, \
102 void *ctx_ptr, uint32_t block_num, \
103 uint32_t entry_num, uint32_t entry_offset) { \
104 (void) fs; \
105 (void) entry_offset; \
106 (void) entry; \
107 (void) ctx_ptr; \
108 (void) block_num; \
109 (void) entry_num; \
110 return false; \
111 }
112
113struct ext2_sblock {
114 uint32_t inodes_count;
115 uint32_t blocks_count;
116 uint32_t r_blocks_count;
117 uint32_t free_blocks_count;
118 uint32_t free_inodes_count;
119 uint32_t first_data_block;
120 uint32_t log_block_size;
121 uint32_t log_frag_size;
122 uint32_t blocks_per_group;
123 uint32_t frags_per_group;
124 uint32_t inodes_per_group;
125 uint32_t mtime;
126 uint32_t wtime;
127 uint16_t mnt_count;
128 uint16_t max_mnt_count;
129 uint16_t magic;
130 uint16_t state;
131 uint16_t errors;
132 uint16_t minor_rev_level;
133 uint32_t lastcheck;
134 uint32_t checkinterval;
135 uint32_t creator_os;
136 uint32_t rev_level;
137 uint16_t def_resuid;
138 uint16_t def_resgid;
139 uint32_t first_ino;
140 uint16_t inode_size;
141 uint16_t block_group_nr;
142 uint32_t feature_compat;
143 uint32_t feature_incompat;
144 uint32_t feature_ro_compat;
145 uint8_t uuid[16];
146 char volume_name[16];
147 char last_mounted[64];
148 uint32_t algorithm_usage_bitmap;
149 uint8_t prealloc_blocks;
150 uint8_t prealloc_dir_blocks;
151 uint16_t padding;
152
153 union {
154 struct {
155 uint32_t journal_uuid[4];
156 uint32_t journal_inum;
157 uint32_t journal_dev;
158 uint32_t last_orphan;
159 uint32_t hash_seed[4];
160 uint8_t def_hash_version;
161 uint8_t journal_backup_type;
162 uint16_t desc_size;
163 uint32_t default_mount_opts;
164 uint32_t first_meta_bg;
165 uint32_t mkfs_time;
166 uint32_t journal_blocks[17];
167 uint32_t quota_group_inode; // [4] → offset 0x258
168 uint32_t quota_project_inode; // [5] → offset 0x25C
169 };
170 uint32_t reserved[204];
171 };
172} __packed;
173
174struct ext2_group_desc {
175 uint32_t block_bitmap;
176 uint32_t inode_bitmap;
177 uint32_t inode_table;
178 uint16_t free_blocks_count;
179 uint16_t free_inodes_count;
180 uint16_t used_dirs_count;
181 uint16_t pad;
182 uint32_t reserved[3];
183} __attribute__((__packed__));
184
185struct ext2_inode {
186 mode_t mode;
187 uint16_t uid;
188 uint32_t size;
189 uint32_t atime;
190 uint32_t ctime;
191 uint32_t mtime;
192 uint32_t dtime;
193 uint16_t gid;
194 uint16_t links_count;
195 uint32_t blocks;
196 uint32_t flags;
197 uint32_t osd1;
198
199 uint32_t block[EXT2_NBLOCKS];
200 uint32_t generation;
201 uint32_t file_acl;
202 uint32_t dir_acl;
203 uint32_t faddr;
204 uint8_t frag[16];
205 uint8_t osd2[12];
206};
207
208struct ext2_full_inode {
209 struct ext2_inode node;
210 inode_t inode_num;
211 struct bcache_entry *ent;
212};
213
214struct ext2_dir_entry {
215 inode_t inode;
216 uint16_t rec_len;
217 uint8_t name_len;
218 uint8_t file_type;
219 char name[EXT2_NAME_LEN + 1];
220} __packed;
221
222struct ext2_fs {
223 struct partition *partition;
224 struct block_device *drive;
225 struct ext2_sblock *sblock;
226 struct ext2_group_desc *group_desc;
227 struct bcache_entry *sbcache_ent;
228 struct bcache_entry *gdesc_cache_ent;
229 uint32_t num_groups;
230 uint32_t inodes_count;
231 uint32_t inodes_per_group;
232 uint32_t blocks_per_group;
233 uint32_t block_size;
234 uint32_t sectors_per_block;
235 uint16_t inode_size;
236
237 /* lock the fs struct */
238 struct spinlock lock;
239};
240
241ERR_FACILITY_EXTERN(ext2);
242
243enum ext2_errno {
244 EXT2_ERR_FS_INVALID = ERR_DELTA_START,
245 EXT2_ERR_NO_INODE,
246
247};
248
249typedef bool (*dir_entry_callback)(struct ext2_fs *fs,
250 struct ext2_dir_entry *entry, void *ctx,
251 uint32_t block_num, uint32_t entry_num,
252 uint32_t entry_offset);
253
254typedef void (*ext2_block_visitor)(struct ext2_fs *fs, struct ext2_inode *inode,
255 uint32_t depth, uint32_t *block_ptr,
256 void *user_data);
257
258//
259//
260// R/W + Mount
261//
262//
263
264uint8_t *ext2_block_read(struct ext2_fs *fs, uint32_t block_num,
265 struct bcache_entry **out);
266
267bool ext2_block_write(struct ext2_fs *fs, struct bcache_entry *ent,
268 enum bio_request_priority prio);
269
270bool ext2_read_superblock(struct partition *, struct ext2_sblock *sblock);
271
272bool ext2_write_superblock(struct ext2_fs *fs);
273bool ext2_write_group_desc(struct ext2_fs *fs);
274
275enum errno ext2_mount(struct partition *, struct ext2_fs *fs,
276 struct ext2_sblock *sblock, struct vfs_node *out_node);
277
278struct vfs_node *ext2_g_mount(struct partition *);
279
280struct ext2_inode *ext2_inode_read(struct ext2_fs *fs, inode_t inode_idx,
281 struct bcache_entry **out_ent);
282
283bool ext2_inode_write(struct ext2_fs *fs, inode_t inode_num,
284 const struct ext2_inode *inode);
285
286uint32_t ext2_get_or_set_block(struct ext2_fs *fs, struct ext2_inode *inode,
287 uint32_t block_index, uint32_t new_block_num,
288 bool allocate, bool *was_allocated);
289
290//
291//
292// Util
293//
294//
295
296uint32_t ext2_block_to_lba(struct ext2_fs *fs, uint32_t block_num);
297bool ext2_dirent_valid(struct ext2_dir_entry *entry);
298void ext2_init_inode(struct ext2_inode *new_inode, mode_t mode);
299
300void ext2_init_dirent(struct ext2_fs *fs, struct ext2_dir_entry *new_entry,
301 inode_t inode_num, const char *name, uint8_t type);
302
303uint8_t ext2_extract_ftype(mode_t mode);
304
305bool ext2_walk_dir(struct ext2_fs *fs, struct ext2_full_inode *dir,
306 dir_entry_callback cb, void *ctx);
307
308static inline void ext2_dealloc_inode(struct ext2_full_inode *ino) {
309 kfree(ino);
310}
311
312static inline uint32_t ext2_get_block_group(struct ext2_fs *fs,
313 uint32_t block) {
314 return (block - 1) / fs->sblock->blocks_per_group;
315}
316
317static inline uint32_t ext2_get_inode_group(struct ext2_fs *fs, inode_t inode) {
318 return (inode - 1) / fs->inodes_per_group;
319}
320
321static inline enum irql ext2_fs_lock(struct ext2_fs *fs) {
322 return spin_lock(&fs->lock);
323}
324
325static inline void ext2_fs_unlock(struct ext2_fs *fs, enum irql i) {
326 spin_unlock(&fs->lock, i);
327}
328
329static inline void ext2_prefetch_block(struct ext2_fs *fs, uint32_t block) {
330 uint32_t lba = ext2_block_to_lba(fs, block_num: block);
331 bcache_prefetch_async(disk: fs->drive, lba, block_size: fs->block_size,
332 spb: fs->sectors_per_block);
333}
334
335static inline void ext2_inode_lock(struct ext2_full_inode *ino) {
336 bcache_ent_lock(ent: ino->ent);
337}
338
339static inline void ext2_inode_unlock(struct ext2_full_inode *ino) {
340 bcache_ent_unlock(ent: ino->ent);
341}
342
343static inline uint8_t *ext2_create_bcache_ent(struct ext2_fs *fs,
344 uint32_t block,
345 struct bcache_entry **out) {
346 return bcache_create_ent(disk: fs->drive, lba: ext2_block_to_lba(fs, block_num: block),
347 block_size: fs->block_size, sectors_per_block: fs->sectors_per_block, false, out_entry: out);
348}
349
350//
351//
352// Higher level stuff
353//
354//
355
356enum errno ext2_link_file(struct ext2_fs *fs, struct ext2_full_inode *dir_inode,
357 struct ext2_full_inode *inode, const char *name,
358 uint8_t type, bool increment_links);
359
360enum errno ext2_unlink_file(struct ext2_fs *fs,
361 struct ext2_full_inode *dir_inode, const char *name,
362 bool free_blocks, bool decrement_links);
363
364enum errno ext2_create_file(struct ext2_fs *fs,
365 struct ext2_full_inode *parent_dir,
366 const char *name, mode_t mode,
367 bool increment_links);
368
369enum errno ext2_symlink_file(struct ext2_fs *fs,
370 struct ext2_full_inode *dir_inode,
371 const char *name, const char *target);
372
373enum errno ext2_write_file(struct ext2_fs *fs, struct ext2_full_inode *inode,
374 uint32_t offset, const uint8_t *src, uint32_t size);
375
376enum errno ext2_read_file(struct ext2_fs *fs, struct ext2_full_inode *inode,
377 uint32_t offset, uint8_t *buffer, uint64_t length);
378
379enum errno ext2_truncate_file(struct ext2_fs *fs, struct ext2_full_inode *inode,
380 uint32_t new_size);
381
382enum errno ext2_chmod(struct ext2_fs *fs, struct ext2_full_inode *node,
383 mode_t new_mode);
384
385enum errno ext2_chown(struct ext2_fs *fs, struct ext2_full_inode *node,
386 uid_t new_uid, gid_t new_gid);
387
388enum errno ext2_readlink(struct ext2_fs *fs, struct ext2_full_inode *node,
389 char *buf, uint64_t size);
390
391struct ext2_full_inode *ext2_find_file_in_dir(struct ext2_fs *fs,
392 struct ext2_full_inode *dir_inode,
393 const char *fname,
394 uint8_t *type_out);
395
396bool ext2_dir_contains_file(struct ext2_fs *fs,
397 struct ext2_full_inode *dir_inode,
398 const char *fname);
399
400enum errno ext2_mkdir(struct ext2_fs *fs, struct ext2_full_inode *parent_dir,
401 const char *name, mode_t mode);
402
403enum errno ext2_rmdir(struct ext2_fs *fs, struct ext2_full_inode *parent_dir,
404 const char *name);
405
406enum errno ext2_readdir(struct ext2_fs *fs, struct ext2_full_inode *dir_inode,
407 struct ext2_dir_entry *out, uint32_t entry_offset);
408
409//
410//
411//
412// Alloc/dealloc
413//
414//
415
416uint32_t ext2_alloc_block(struct ext2_fs *fs);
417bool ext2_free_block(struct ext2_fs *fs, uint32_t block_num);
418inode_t ext2_alloc_inode(struct ext2_fs *fs);
419bool ext2_free_inode(struct ext2_fs *fs, inode_t inode_num);
420
421bool ext2_find_first_available(struct ext2_fs *fs, struct ext2_full_inode *dir,
422 uint32_t *new_block);
423
424void ext2_traverse_inode_blocks(struct ext2_fs *fs, struct ext2_inode *inode,
425 ext2_block_visitor visitor, void *user_data,
426 bool readahead);
427
428void ext2_g_print(struct partition *);
429
430void ext2_dump_file_data(struct ext2_fs *fs, const struct ext2_inode *inode,
431 uint32_t start_block_index, uint32_t length);
432
433#pragma once
434