]> git.ipfire.org Git - thirdparty/e2fsprogs.git/blame - lib/ext2fs/bmap.c
e2fsck: detect holes in extent-mapped directories
[thirdparty/e2fsprogs.git] / lib / ext2fs / bmap.c
CommitLineData
30fab293 1/*
80e808fc 2 * bmap.c --- logical to physical block mapping
30fab293
TT
3 *
4 * Copyright (C) 1997 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12#include <stdio.h>
13#include <string.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
cc9bf5d2 17#include <errno.h>
30fab293 18
b5abe6fa 19#include "ext2_fs.h"
30fab293
TT
20#include "ext2fs.h"
21
78d8f90f 22#if defined(__GNUC__) && !defined(NO_INLINE_FUNCS)
30fab293
TT
23#define _BMAP_INLINE_ __inline__
24#else
25#define _BMAP_INLINE_
26#endif
27
31dbecd4 28extern errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino,
efc6f628 29 struct ext2_inode *inode,
30fab293
TT
30 char *block_buf, int bmap_flags,
31 blk_t block, blk_t *phys_blk);
32
30fab293
TT
33#define inode_bmap(inode, nr) ((inode)->i_block[(nr)])
34
efc6f628
TT
35static _BMAP_INLINE_ errcode_t block_ind_bmap(ext2_filsys fs, int flags,
36 blk_t ind, char *block_buf,
30fab293
TT
37 int *blocks_alloc,
38 blk_t nr, blk_t *ret_blk)
39{
40 errcode_t retval;
41 blk_t b;
42
43 if (!ind) {
1d667534
TT
44 if (flags & BMAP_SET)
45 return EXT2_ET_SET_BMAP_NO_IND;
30fab293
TT
46 *ret_blk = 0;
47 return 0;
48 }
49 retval = io_channel_read_blk(fs->io, ind, 1, block_buf);
50 if (retval)
51 return retval;
52
1d667534
TT
53 if (flags & BMAP_SET) {
54 b = *ret_blk;
126a291c
TT
55#ifdef WORDS_BIGENDIAN
56 b = ext2fs_swab32(b);
1d667534
TT
57#endif
58 ((blk_t *) block_buf)[nr] = b;
59 return io_channel_write_blk(fs->io, ind, 1, block_buf);
60 }
61
30fab293
TT
62 b = ((blk_t *) block_buf)[nr];
63
126a291c
TT
64#ifdef WORDS_BIGENDIAN
65 b = ext2fs_swab32(b);
5df55d7f 66#endif
30fab293
TT
67
68 if (!b && (flags & BMAP_ALLOC)) {
69 b = nr ? ((blk_t *) block_buf)[nr-1] : 0;
70 retval = ext2fs_alloc_block(fs, b,
71 block_buf + fs->blocksize, &b);
72 if (retval)
73 return retval;
74
126a291c
TT
75#ifdef WORDS_BIGENDIAN
76 ((blk_t *) block_buf)[nr] = ext2fs_swab32(b);
77#else
78 ((blk_t *) block_buf)[nr] = b;
5df55d7f 79#endif
30fab293
TT
80
81 retval = io_channel_write_blk(fs->io, ind, 1, block_buf);
82 if (retval)
83 return retval;
84
85 (*blocks_alloc)++;
86 }
87
88 *ret_blk = b;
89 return 0;
90}
91
546a1ff1 92static _BMAP_INLINE_ errcode_t block_dind_bmap(ext2_filsys fs, int flags,
efc6f628 93 blk_t dind, char *block_buf,
30fab293
TT
94 int *blocks_alloc,
95 blk_t nr, blk_t *ret_blk)
96{
97 blk_t b;
98 errcode_t retval;
2eb374c9 99 blk_t addr_per_block;
efc6f628 100
2eb374c9 101 addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293 102
efc6f628 103 retval = block_ind_bmap(fs, flags & ~BMAP_SET, dind, block_buf,
1d667534 104 blocks_alloc, nr / addr_per_block, &b);
30fab293
TT
105 if (retval)
106 return retval;
107 retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc,
108 nr % addr_per_block, ret_blk);
109 return retval;
110}
111
546a1ff1 112static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags,
efc6f628 113 blk_t tind, char *block_buf,
30fab293
TT
114 int *blocks_alloc,
115 blk_t nr, blk_t *ret_blk)
116{
117 blk_t b;
118 errcode_t retval;
2eb374c9 119 blk_t addr_per_block;
efc6f628 120
2eb374c9 121 addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293 122
efc6f628 123 retval = block_dind_bmap(fs, flags & ~BMAP_SET, tind, block_buf,
1d667534 124 blocks_alloc, nr / addr_per_block, &b);
30fab293
TT
125 if (retval)
126 return retval;
127 retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc,
128 nr % addr_per_block, ret_blk);
129 return retval;
130}
131
cc9bf5d2
TT
132errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
133 char *block_buf, int bmap_flags, blk64_t block,
134 int *ret_flags, blk64_t *phys_blk)
30fab293
TT
135{
136 struct ext2_inode inode_buf;
cc9bf5d2 137 ext2_extent_handle_t handle = 0;
2eb374c9 138 blk_t addr_per_block;
cc9bf5d2 139 blk_t b, blk32;
30fab293
TT
140 char *buf = 0;
141 errcode_t retval = 0;
1d667534 142 int blocks_alloc = 0, inode_dirty = 0;
30fab293 143
1d667534
TT
144 if (!(bmap_flags & BMAP_SET))
145 *phys_blk = 0;
30fab293 146
cc9bf5d2
TT
147 if (ret_flags)
148 *ret_flags = 0;
149
30fab293
TT
150 /* Read inode structure if necessary */
151 if (!inode) {
152 retval = ext2fs_read_inode(fs, ino, &inode_buf);
b38cd283 153 if (retval)
30fab293
TT
154 return retval;
155 inode = &inode_buf;
156 }
2eb374c9 157 addr_per_block = (blk_t) fs->blocksize >> 2;
30fab293 158
cc9bf5d2
TT
159 if (inode->i_flags & EXT4_EXTENTS_FL) {
160 struct ext2fs_extent extent;
2d328bb7 161 unsigned int offset;
cc9bf5d2 162
84b239ae 163 retval = ext2fs_extent_open2(fs, ino, inode, &handle);
cc9bf5d2
TT
164 if (retval)
165 goto done;
ec9d6dd3
TT
166 if (bmap_flags & BMAP_SET) {
167 retval = ext2fs_extent_set_bmap(handle, block,
168 *phys_blk, 0);
169 goto done;
170 }
cc9bf5d2
TT
171 retval = ext2fs_extent_goto(handle, block);
172 if (retval) {
173 /* If the extent is not found, return phys_blk = 0 */
174 if (retval == EXT2_ET_EXTENT_NOT_FOUND)
9033faf5 175 goto got_block;
cc9bf5d2
TT
176 goto done;
177 }
178 retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
179 if (retval)
180 goto done;
181 offset = block - extent.e_lblk;
182 if (block >= extent.e_lblk && (offset <= extent.e_len)) {
183 *phys_blk = extent.e_pblk + offset;
184 if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
185 *ret_flags |= BMAP_RET_UNINIT;
186 }
9033faf5 187 got_block:
ec9d6dd3
TT
188 if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
189 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
190 if (retval)
191 goto done;
192 retval = ext2fs_extent_set_bmap(handle, block,
193 (blk64_t) b, 0);
194 if (retval)
195 goto done;
9033faf5
TT
196 /* Update inode after setting extent */
197 retval = ext2fs_read_inode(fs, ino, inode);
198 if (retval)
199 return retval;
ec9d6dd3
TT
200 blocks_alloc++;
201 *phys_blk = b;
202 }
cc9bf5d2
TT
203 retval = 0;
204 goto done;
205 }
206
30fab293 207 if (!block_buf) {
ee01079a 208 retval = ext2fs_get_array(2, fs->blocksize, &buf);
7b4e4534
TT
209 if (retval)
210 return retval;
30fab293
TT
211 block_buf = buf;
212 }
213
214 if (block < EXT2_NDIR_BLOCKS) {
1d667534
TT
215 if (bmap_flags & BMAP_SET) {
216 b = *phys_blk;
126a291c
TT
217#ifdef WORDS_BIGENDIAN
218 b = ext2fs_swab32(b);
1d667534
TT
219#endif
220 inode_bmap(inode, block) = b;
221 inode_dirty++;
222 goto done;
223 }
224
30fab293
TT
225 *phys_blk = inode_bmap(inode, block);
226 b = block ? inode_bmap(inode, block-1) : 0;
efc6f628 227
30fab293
TT
228 if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
229 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
230 if (retval)
231 goto done;
232 inode_bmap(inode, block) = b;
233 blocks_alloc++;
234 *phys_blk = b;
235 }
236 goto done;
237 }
efc6f628 238
30fab293
TT
239 /* Indirect block */
240 block -= EXT2_NDIR_BLOCKS;
cc9bf5d2 241 blk32 = *phys_blk;
30fab293
TT
242 if (block < addr_per_block) {
243 b = inode_bmap(inode, EXT2_IND_BLOCK);
244 if (!b) {
1d667534
TT
245 if (!(bmap_flags & BMAP_ALLOC)) {
246 if (bmap_flags & BMAP_SET)
247 retval = EXT2_ET_SET_BMAP_NO_IND;
248 goto done;
249 }
30fab293
TT
250
251 b = inode_bmap(inode, EXT2_IND_BLOCK-1);
252 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
253 if (retval)
254 goto done;
255 inode_bmap(inode, EXT2_IND_BLOCK) = b;
256 blocks_alloc++;
257 }
efc6f628 258 retval = block_ind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2
TT
259 &blocks_alloc, block, &blk32);
260 if (retval == 0)
261 *phys_blk = blk32;
30fab293
TT
262 goto done;
263 }
efc6f628 264
30fab293
TT
265 /* Doubly indirect block */
266 block -= addr_per_block;
267 if (block < addr_per_block * addr_per_block) {
268 b = inode_bmap(inode, EXT2_DIND_BLOCK);
269 if (!b) {
1d667534
TT
270 if (!(bmap_flags & BMAP_ALLOC)) {
271 if (bmap_flags & BMAP_SET)
272 retval = EXT2_ET_SET_BMAP_NO_IND;
273 goto done;
274 }
30fab293
TT
275
276 b = inode_bmap(inode, EXT2_IND_BLOCK);
277 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
278 if (retval)
279 goto done;
280 inode_bmap(inode, EXT2_DIND_BLOCK) = b;
281 blocks_alloc++;
282 }
efc6f628 283 retval = block_dind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2
TT
284 &blocks_alloc, block, &blk32);
285 if (retval == 0)
286 *phys_blk = blk32;
30fab293
TT
287 goto done;
288 }
289
290 /* Triply indirect block */
291 block -= addr_per_block * addr_per_block;
292 b = inode_bmap(inode, EXT2_TIND_BLOCK);
293 if (!b) {
1d667534
TT
294 if (!(bmap_flags & BMAP_ALLOC)) {
295 if (bmap_flags & BMAP_SET)
296 retval = EXT2_ET_SET_BMAP_NO_IND;
30fab293 297 goto done;
1d667534 298 }
30fab293
TT
299
300 b = inode_bmap(inode, EXT2_DIND_BLOCK);
301 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
302 if (retval)
303 goto done;
304 inode_bmap(inode, EXT2_TIND_BLOCK) = b;
305 blocks_alloc++;
306 }
efc6f628 307 retval = block_tind_bmap(fs, bmap_flags, b, block_buf,
cc9bf5d2
TT
308 &blocks_alloc, block, &blk32);
309 if (retval == 0)
310 *phys_blk = blk32;
30fab293
TT
311done:
312 if (buf)
c4e3d3f3 313 ext2fs_free_mem(&buf);
cc9bf5d2
TT
314 if (handle)
315 ext2fs_extent_free(handle);
1d667534 316 if ((retval == 0) && (blocks_alloc || inode_dirty)) {
1ca1059f 317 ext2fs_iblk_add_blocks(fs, inode, blocks_alloc);
30fab293
TT
318 retval = ext2fs_write_inode(fs, ino, inode);
319 }
320 return retval;
321}
322
cc9bf5d2
TT
323errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
324 char *block_buf, int bmap_flags, blk_t block,
325 blk_t *phys_blk)
326{
327 errcode_t ret;
328 blk64_t ret_blk;
329
330 ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block,
331 0, &ret_blk);
332 if (ret)
333 return ret;
334 if (ret_blk >= ((long long) 1 << 32))
335 return EOVERFLOW;
336 *phys_blk = ret_blk;
337 return 0;
338}