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 ? ext2fs_le32_to_cpu(((blk_t *)block_buf)[nr - 1]) : ind;
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 (!ext2fs_has_feature_bigalloc(fs->super))
151 base_block = lblk & ~EXT2FS_CLUSTER_MASK(fs);
153 * Except for the logical block (lblk) that was passed in, search all
154 * blocks in this logical cluster for a mapping to a physical cluster.
155 * If any such map exists, calculate the physical block that maps to
156 * the logical block and return that.
158 * The old code wouldn't even look if (block % cluster_ratio) == 0;
159 * this is incorrect if we're allocating blocks in reverse order.
161 for (i = 0; i < EXT2FS_CLUSTER_RATIO(fs); i++) {
162 if (base_block + i == lblk)
164 extent_bmap(fs, ino, inode, handle, 0, 0,
165 base_block + i, 0, 0, &pblock);
171 *phys_blk = pblock - i + (lblk - base_block);
175 /* Try to map a logical block to an already-allocated physical cluster. */
176 errcode_t ext2fs_map_cluster_block(ext2_filsys fs, ext2_ino_t ino,
177 struct ext2_inode *inode, blk64_t lblk,
180 ext2_extent_handle_t handle;
183 /* Need bigalloc and extents to be enabled */
185 if (!ext2fs_has_feature_bigalloc(fs->super) ||
186 !(inode->i_flags & EXT4_EXTENTS_FL))
189 retval = ext2fs_extent_open2(fs, ino, inode, &handle);
193 retval = implied_cluster_alloc(fs, ino, inode, handle, lblk, pblk);
198 ext2fs_extent_free(handle);
203 static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
204 struct ext2_inode *inode,
205 ext2_extent_handle_t handle,
206 char *block_buf, int bmap_flags, blk64_t block,
207 int *ret_flags, int *blocks_alloc,
210 struct blk_alloc_ctx alloc_ctx;
211 struct ext2fs_extent extent;
213 errcode_t retval = 0;
218 set_flags = bmap_flags & BMAP_UNINIT ? EXT2_EXTENT_SET_BMAP_UNINIT : 0;
220 if (bmap_flags & BMAP_SET) {
221 retval = ext2fs_extent_set_bmap(handle, block,
222 *phys_blk, set_flags);
225 retval = ext2fs_extent_goto(handle, block);
227 /* If the extent is not found, return phys_blk = 0 */
228 if (retval == EXT2_ET_EXTENT_NOT_FOUND) {
229 extent.e_lblk = block;
234 retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
237 offset = block - extent.e_lblk;
238 if (block >= extent.e_lblk && (offset <= extent.e_len)) {
239 *phys_blk = extent.e_pblk + offset;
240 if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
241 *ret_flags |= BMAP_RET_UNINIT;
244 if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
245 implied_cluster_alloc(fs, ino, inode, handle, block, &blk64);
248 retval = extent_bmap(fs, ino, inode, handle, block_buf,
249 0, block-1, 0, blocks_alloc, &blk64);
251 blk64 = ext2fs_find_inode_goal(fs, ino, inode, block);
253 alloc_ctx.inode = inode;
254 alloc_ctx.lblk = extent.e_lblk;
255 alloc_ctx.flags = BLOCK_ALLOC_DATA;
256 retval = ext2fs_alloc_block3(fs, blk64, block_buf, &blk64,
260 blk64 &= ~EXT2FS_CLUSTER_MASK(fs);
261 blk64 += EXT2FS_CLUSTER_MASK(fs) & block;
264 retval = ext2fs_extent_set_bmap(handle, block,
267 ext2fs_block_alloc_stats2(fs, blk64, -1);
270 /* Update inode after setting extent */
271 retval = ext2fs_read_inode(fs, ino, inode);
274 *blocks_alloc += alloc;
280 int ext2fs_file_block_offset_too_big(ext2_filsys fs,
281 struct ext2_inode *inode,
284 blk64_t addr_per_block, max_map_block;
286 /* Kernel seems to cut us off at 4294967294 blocks */
287 if (offset >= (1ULL << 32) - 1)
290 if (inode->i_flags & EXT4_EXTENTS_FL)
293 addr_per_block = fs->blocksize >> 2;
294 max_map_block = addr_per_block;
295 max_map_block += addr_per_block * addr_per_block;
296 max_map_block += addr_per_block * addr_per_block * addr_per_block;
299 return offset >= max_map_block;
302 errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
303 char *block_buf, int bmap_flags, blk64_t block,
304 int *ret_flags, blk64_t *phys_blk)
306 struct ext2_inode inode_buf;
307 ext2_extent_handle_t handle = 0;
308 blk_t addr_per_block;
312 errcode_t retval = 0;
313 int blocks_alloc = 0, inode_dirty = 0;
314 struct blk_alloc_ctx alloc_ctx = {
318 .flags = BLOCK_ALLOC_DATA,
321 if (!(bmap_flags & BMAP_SET))
327 /* Read inode structure if necessary */
329 retval = ext2fs_read_inode(fs, ino, &inode_buf);
334 addr_per_block = (blk_t) fs->blocksize >> 2;
336 if (ext2fs_file_block_offset_too_big(fs, inode, block))
337 return EXT2_ET_FILE_TOO_BIG;
340 * If an inode has inline data, that means that it doesn't have
341 * any blocks and we shouldn't map any blocks for it.
343 if (inode->i_flags & EXT4_INLINE_DATA_FL)
344 return EXT2_ET_INLINE_DATA_NO_BLOCK;
347 retval = ext2fs_get_array(2, fs->blocksize, &buf);
353 if (inode->i_flags & EXT4_EXTENTS_FL) {
354 retval = ext2fs_extent_open2(fs, ino, inode, &handle);
357 retval = extent_bmap(fs, ino, inode, handle, block_buf,
358 bmap_flags, block, ret_flags,
359 &blocks_alloc, phys_blk);
363 if (block < EXT2_NDIR_BLOCKS) {
364 if (bmap_flags & BMAP_SET) {
366 inode_bmap(inode, block) = b;
371 *phys_blk = inode_bmap(inode, block);
372 b = block ? inode_bmap(inode, block - 1) :
373 ext2fs_find_inode_goal(fs, ino, inode, block);
375 if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
377 retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
382 inode_bmap(inode, block) = b;
390 block -= EXT2_NDIR_BLOCKS;
392 if (block < addr_per_block) {
393 b = inode_bmap(inode, EXT2_IND_BLOCK);
395 if (!(bmap_flags & BMAP_ALLOC)) {
396 if (bmap_flags & BMAP_SET)
397 retval = EXT2_ET_SET_BMAP_NO_IND;
401 b = inode_bmap(inode, EXT2_IND_BLOCK-1);
403 retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
408 inode_bmap(inode, EXT2_IND_BLOCK) = b;
411 retval = block_ind_bmap(fs, bmap_flags, b, block_buf,
412 &blocks_alloc, block, &blk32);
418 /* Doubly indirect block */
419 block -= addr_per_block;
420 if (block < addr_per_block * addr_per_block) {
421 b = inode_bmap(inode, EXT2_DIND_BLOCK);
423 if (!(bmap_flags & BMAP_ALLOC)) {
424 if (bmap_flags & BMAP_SET)
425 retval = EXT2_ET_SET_BMAP_NO_IND;
429 b = inode_bmap(inode, EXT2_IND_BLOCK);
431 retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
436 inode_bmap(inode, EXT2_DIND_BLOCK) = b;
439 retval = block_dind_bmap(fs, bmap_flags, b, block_buf,
440 &blocks_alloc, block, &blk32);
446 /* Triply indirect block */
447 block -= addr_per_block * addr_per_block;
448 b = inode_bmap(inode, EXT2_TIND_BLOCK);
450 if (!(bmap_flags & BMAP_ALLOC)) {
451 if (bmap_flags & BMAP_SET)
452 retval = EXT2_ET_SET_BMAP_NO_IND;
456 b = inode_bmap(inode, EXT2_DIND_BLOCK);
458 retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64,
463 inode_bmap(inode, EXT2_TIND_BLOCK) = b;
466 retval = block_tind_bmap(fs, bmap_flags, b, block_buf,
467 &blocks_alloc, block, &blk32);
471 if (*phys_blk && retval == 0 && (bmap_flags & BMAP_ZERO))
472 retval = ext2fs_zero_blocks2(fs, *phys_blk, 1, NULL, NULL);
474 ext2fs_free_mem(&buf);
476 ext2fs_extent_free(handle);
477 if ((retval == 0) && (blocks_alloc || inode_dirty)) {
478 ext2fs_iblk_add_blocks(fs, inode, blocks_alloc);
479 retval = ext2fs_write_inode(fs, ino, inode);
484 errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
485 char *block_buf, int bmap_flags, blk_t block,
489 blk64_t ret_blk = *phys_blk;
491 ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block,
495 if (ret_blk >= ((long long) 1 << 32))