2 * bmap.c --- logical to physical block mapping
4 * Copyright (C) 1997 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
23 #if defined(__GNUC__) && !defined(NO_INLINE_FUNCS)
24 #define _BMAP_INLINE_ __inline__
29 extern errcode_t
ext2fs_bmap(ext2_filsys fs
, ext2_ino_t ino
,
30 struct ext2_inode
*inode
,
31 char *block_buf
, int bmap_flags
,
32 blk_t block
, blk_t
*phys_blk
);
34 #define inode_bmap(inode, nr) ((inode)->i_block[(nr)])
36 static _BMAP_INLINE_ errcode_t
block_ind_bmap(ext2_filsys fs
, int flags
,
37 blk_t ind
, char *block_buf
,
39 blk_t nr
, blk_t
*ret_blk
)
46 return EXT2_ET_SET_BMAP_NO_IND
;
50 retval
= io_channel_read_blk(fs
->io
, ind
, 1, block_buf
);
54 if (flags
& BMAP_SET
) {
56 #ifdef WORDS_BIGENDIAN
59 ((blk_t
*) block_buf
)[nr
] = b
;
60 return io_channel_write_blk(fs
->io
, ind
, 1, block_buf
);
63 b
= ((blk_t
*) block_buf
)[nr
];
65 #ifdef WORDS_BIGENDIAN
69 if (!b
&& (flags
& BMAP_ALLOC
)) {
70 b
= nr
? ((blk_t
*) block_buf
)[nr
-1] : 0;
71 retval
= ext2fs_alloc_block(fs
, b
,
72 block_buf
+ fs
->blocksize
, &b
);
76 #ifdef WORDS_BIGENDIAN
77 ((blk_t
*) block_buf
)[nr
] = ext2fs_swab32(b
);
79 ((blk_t
*) block_buf
)[nr
] = b
;
82 retval
= io_channel_write_blk(fs
->io
, ind
, 1, block_buf
);
93 static _BMAP_INLINE_ errcode_t
block_dind_bmap(ext2_filsys fs
, int flags
,
94 blk_t dind
, char *block_buf
,
96 blk_t nr
, blk_t
*ret_blk
)
100 blk_t addr_per_block
;
102 addr_per_block
= (blk_t
) fs
->blocksize
>> 2;
104 retval
= block_ind_bmap(fs
, flags
& ~BMAP_SET
, dind
, block_buf
,
105 blocks_alloc
, nr
/ addr_per_block
, &b
);
108 retval
= block_ind_bmap(fs
, flags
, b
, block_buf
, blocks_alloc
,
109 nr
% addr_per_block
, ret_blk
);
113 static _BMAP_INLINE_ errcode_t
block_tind_bmap(ext2_filsys fs
, int flags
,
114 blk_t tind
, char *block_buf
,
116 blk_t nr
, blk_t
*ret_blk
)
120 blk_t addr_per_block
;
122 addr_per_block
= (blk_t
) fs
->blocksize
>> 2;
124 retval
= block_dind_bmap(fs
, flags
& ~BMAP_SET
, tind
, block_buf
,
125 blocks_alloc
, nr
/ addr_per_block
, &b
);
128 retval
= block_ind_bmap(fs
, flags
, b
, block_buf
, blocks_alloc
,
129 nr
% addr_per_block
, ret_blk
);
133 static errcode_t
extent_bmap(ext2_filsys fs
, ext2_ino_t ino
,
134 struct ext2_inode
*inode
,
135 ext2_extent_handle_t handle
,
136 char *block_buf
, int bmap_flags
, blk64_t block
,
137 int *ret_flags
, int *blocks_alloc
,
140 static errcode_t
implied_cluster_alloc(ext2_filsys fs
, ext2_ino_t ino
,
141 struct ext2_inode
*inode
,
142 ext2_extent_handle_t handle
,
143 blk64_t lblk
, blk64_t
*phys_blk
)
145 blk64_t base_block
, pblock
= 0;
148 if (!EXT2_HAS_RO_COMPAT_FEATURE(fs
->super
,
149 EXT4_FEATURE_RO_COMPAT_BIGALLOC
))
152 base_block
= lblk
& ~EXT2FS_CLUSTER_MASK(fs
);
154 * Except for the logical block (lblk) that was passed in, search all
155 * blocks in this logical cluster for a mapping to a physical cluster.
156 * If any such map exists, calculate the physical block that maps to
157 * the logical block and return that.
159 * The old code wouldn't even look if (block % cluster_ratio) == 0;
160 * this is incorrect if we're allocating blocks in reverse order.
162 for (i
= 0; i
< EXT2FS_CLUSTER_RATIO(fs
); i
++) {
163 if (base_block
+ i
== lblk
)
165 extent_bmap(fs
, ino
, inode
, handle
, 0, 0,
166 base_block
+ i
, 0, 0, &pblock
);
172 *phys_blk
= pblock
- i
+ (lblk
- base_block
);
176 /* Try to map a logical block to an already-allocated physical cluster. */
177 errcode_t
ext2fs_map_cluster_block(ext2_filsys fs
, ext2_ino_t ino
,
178 struct ext2_inode
*inode
, blk64_t lblk
,
181 ext2_extent_handle_t handle
;
184 /* Need bigalloc and extents to be enabled */
186 if (!EXT2_HAS_RO_COMPAT_FEATURE(fs
->super
,
187 EXT4_FEATURE_RO_COMPAT_BIGALLOC
) ||
188 !(inode
->i_flags
& EXT4_EXTENTS_FL
))
191 retval
= ext2fs_extent_open2(fs
, ino
, inode
, &handle
);
195 retval
= implied_cluster_alloc(fs
, ino
, inode
, handle
, lblk
, pblk
);
200 ext2fs_extent_free(handle
);
205 static errcode_t
extent_bmap(ext2_filsys fs
, ext2_ino_t ino
,
206 struct ext2_inode
*inode
,
207 ext2_extent_handle_t handle
,
208 char *block_buf
, int bmap_flags
, blk64_t block
,
209 int *ret_flags
, int *blocks_alloc
,
212 struct ext2fs_extent extent
;
214 errcode_t retval
= 0;
218 if (bmap_flags
& BMAP_SET
) {
219 retval
= ext2fs_extent_set_bmap(handle
, block
,
223 retval
= ext2fs_extent_goto(handle
, block
);
225 /* If the extent is not found, return phys_blk = 0 */
226 if (retval
== EXT2_ET_EXTENT_NOT_FOUND
)
230 retval
= ext2fs_extent_get(handle
, EXT2_EXTENT_CURRENT
, &extent
);
233 offset
= block
- extent
.e_lblk
;
234 if (block
>= extent
.e_lblk
&& (offset
<= extent
.e_len
)) {
235 *phys_blk
= extent
.e_pblk
+ offset
;
236 if (ret_flags
&& extent
.e_flags
& EXT2_EXTENT_FLAGS_UNINIT
)
237 *ret_flags
|= BMAP_RET_UNINIT
;
240 if ((*phys_blk
== 0) && (bmap_flags
& BMAP_ALLOC
)) {
241 implied_cluster_alloc(fs
, ino
, inode
, handle
, block
, &blk64
);
244 retval
= extent_bmap(fs
, ino
, inode
, handle
, block_buf
,
245 0, block
-1, 0, blocks_alloc
, &blk64
);
248 retval
= ext2fs_alloc_block2(fs
, blk64
, block_buf
,
252 blk64
&= ~EXT2FS_CLUSTER_MASK(fs
);
253 blk64
+= EXT2FS_CLUSTER_MASK(fs
) & block
;
256 retval
= ext2fs_extent_set_bmap(handle
, block
,
260 /* Update inode after setting extent */
261 retval
= ext2fs_read_inode(fs
, ino
, inode
);
264 *blocks_alloc
+= alloc
;
270 int ext2fs_file_block_offset_too_big(ext2_filsys fs
,
271 struct ext2_inode
*inode
,
274 blk64_t addr_per_block
, max_map_block
;
276 /* Kernel seems to cut us off at 4294967294 blocks */
277 if (offset
>= (1ULL << 32) - 1)
280 if (inode
->i_flags
& EXT4_EXTENTS_FL
)
283 addr_per_block
= fs
->blocksize
>> 2;
284 max_map_block
= addr_per_block
;
285 max_map_block
+= addr_per_block
* addr_per_block
;
286 max_map_block
+= addr_per_block
* addr_per_block
* addr_per_block
;
289 return offset
>= max_map_block
;
292 errcode_t
ext2fs_bmap2(ext2_filsys fs
, ext2_ino_t ino
, struct ext2_inode
*inode
,
293 char *block_buf
, int bmap_flags
, blk64_t block
,
294 int *ret_flags
, blk64_t
*phys_blk
)
296 struct ext2_inode inode_buf
;
297 ext2_extent_handle_t handle
= 0;
298 blk_t addr_per_block
;
301 errcode_t retval
= 0;
302 int blocks_alloc
= 0, inode_dirty
= 0;
304 if (!(bmap_flags
& BMAP_SET
))
310 /* Read inode structure if necessary */
312 retval
= ext2fs_read_inode(fs
, ino
, &inode_buf
);
317 addr_per_block
= (blk_t
) fs
->blocksize
>> 2;
319 if (ext2fs_file_block_offset_too_big(fs
, inode
, block
))
320 return EXT2_ET_FILE_TOO_BIG
;
323 retval
= ext2fs_get_array(2, fs
->blocksize
, &buf
);
329 if (inode
->i_flags
& EXT4_EXTENTS_FL
) {
330 retval
= ext2fs_extent_open2(fs
, ino
, inode
, &handle
);
333 retval
= extent_bmap(fs
, ino
, inode
, handle
, block_buf
,
334 bmap_flags
, block
, ret_flags
,
335 &blocks_alloc
, phys_blk
);
339 if (block
< EXT2_NDIR_BLOCKS
) {
340 if (bmap_flags
& BMAP_SET
) {
342 inode_bmap(inode
, block
) = b
;
347 *phys_blk
= inode_bmap(inode
, block
);
348 b
= block
? inode_bmap(inode
, block
-1) : 0;
350 if ((*phys_blk
== 0) && (bmap_flags
& BMAP_ALLOC
)) {
351 retval
= ext2fs_alloc_block(fs
, b
, block_buf
, &b
);
354 inode_bmap(inode
, block
) = b
;
362 block
-= EXT2_NDIR_BLOCKS
;
364 if (block
< addr_per_block
) {
365 b
= inode_bmap(inode
, EXT2_IND_BLOCK
);
367 if (!(bmap_flags
& BMAP_ALLOC
)) {
368 if (bmap_flags
& BMAP_SET
)
369 retval
= EXT2_ET_SET_BMAP_NO_IND
;
373 b
= inode_bmap(inode
, EXT2_IND_BLOCK
-1);
374 retval
= ext2fs_alloc_block(fs
, b
, block_buf
, &b
);
377 inode_bmap(inode
, EXT2_IND_BLOCK
) = b
;
380 retval
= block_ind_bmap(fs
, bmap_flags
, b
, block_buf
,
381 &blocks_alloc
, block
, &blk32
);
387 /* Doubly indirect block */
388 block
-= addr_per_block
;
389 if (block
< addr_per_block
* addr_per_block
) {
390 b
= inode_bmap(inode
, EXT2_DIND_BLOCK
);
392 if (!(bmap_flags
& BMAP_ALLOC
)) {
393 if (bmap_flags
& BMAP_SET
)
394 retval
= EXT2_ET_SET_BMAP_NO_IND
;
398 b
= inode_bmap(inode
, EXT2_IND_BLOCK
);
399 retval
= ext2fs_alloc_block(fs
, b
, block_buf
, &b
);
402 inode_bmap(inode
, EXT2_DIND_BLOCK
) = b
;
405 retval
= block_dind_bmap(fs
, bmap_flags
, b
, block_buf
,
406 &blocks_alloc
, block
, &blk32
);
412 /* Triply indirect block */
413 block
-= addr_per_block
* addr_per_block
;
414 b
= inode_bmap(inode
, EXT2_TIND_BLOCK
);
416 if (!(bmap_flags
& BMAP_ALLOC
)) {
417 if (bmap_flags
& BMAP_SET
)
418 retval
= EXT2_ET_SET_BMAP_NO_IND
;
422 b
= inode_bmap(inode
, EXT2_DIND_BLOCK
);
423 retval
= ext2fs_alloc_block(fs
, b
, block_buf
, &b
);
426 inode_bmap(inode
, EXT2_TIND_BLOCK
) = b
;
429 retval
= block_tind_bmap(fs
, bmap_flags
, b
, block_buf
,
430 &blocks_alloc
, block
, &blk32
);
435 ext2fs_free_mem(&buf
);
437 ext2fs_extent_free(handle
);
438 if ((retval
== 0) && (blocks_alloc
|| inode_dirty
)) {
439 ext2fs_iblk_add_blocks(fs
, inode
, blocks_alloc
);
440 retval
= ext2fs_write_inode(fs
, ino
, inode
);
445 errcode_t
ext2fs_bmap(ext2_filsys fs
, ext2_ino_t ino
, struct ext2_inode
*inode
,
446 char *block_buf
, int bmap_flags
, blk_t block
,
450 blk64_t ret_blk
= *phys_blk
;
452 ret
= ext2fs_bmap2(fs
, ino
, inode
, block_buf
, bmap_flags
, block
,
456 if (ret_blk
>= ((long long) 1 << 32))