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,
259 ext2fs_block_alloc_stats2(fs, blk64, -1);
262 /* Update inode after setting extent */
263 retval = ext2fs_read_inode(fs, ino, inode);
266 *blocks_alloc += alloc;
272 int ext2fs_file_block_offset_too_big(ext2_filsys fs,
273 struct ext2_inode *inode,
276 blk64_t addr_per_block, max_map_block;
278 /* Kernel seems to cut us off at 4294967294 blocks */
279 if (offset >= (1ULL << 32) - 1)
282 if (inode->i_flags & EXT4_EXTENTS_FL)
285 addr_per_block = fs->blocksize >> 2;
286 max_map_block = addr_per_block;
287 max_map_block += addr_per_block * addr_per_block;
288 max_map_block += addr_per_block * addr_per_block * addr_per_block;
291 return offset >= max_map_block;
294 errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
295 char *block_buf, int bmap_flags, blk64_t block,
296 int *ret_flags, blk64_t *phys_blk)
298 struct ext2_inode inode_buf;
299 ext2_extent_handle_t handle = 0;
300 blk_t addr_per_block;
303 errcode_t retval = 0;
304 int blocks_alloc = 0, inode_dirty = 0;
306 if (!(bmap_flags & BMAP_SET))
312 /* Read inode structure if necessary */
314 retval = ext2fs_read_inode(fs, ino, &inode_buf);
319 addr_per_block = (blk_t) fs->blocksize >> 2;
321 if (ext2fs_file_block_offset_too_big(fs, inode, block))
322 return EXT2_ET_FILE_TOO_BIG;
325 * If an inode has inline data, that means that it doesn't have
326 * any blocks and we shouldn't map any blocks for it.
328 if (inode->i_flags & EXT4_INLINE_DATA_FL)
329 return EXT2_ET_INLINE_DATA_NO_BLOCK;
332 retval = ext2fs_get_array(2, fs->blocksize, &buf);
338 if (inode->i_flags & EXT4_EXTENTS_FL) {
339 retval = ext2fs_extent_open2(fs, ino, inode, &handle);
342 retval = extent_bmap(fs, ino, inode, handle, block_buf,
343 bmap_flags, block, ret_flags,
344 &blocks_alloc, phys_blk);
348 if (block < EXT2_NDIR_BLOCKS) {
349 if (bmap_flags & BMAP_SET) {
351 inode_bmap(inode, block) = b;
356 *phys_blk = inode_bmap(inode, block);
357 b = block ? inode_bmap(inode, block-1) : 0;
359 if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
360 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
363 inode_bmap(inode, block) = b;
371 block -= EXT2_NDIR_BLOCKS;
373 if (block < addr_per_block) {
374 b = inode_bmap(inode, EXT2_IND_BLOCK);
376 if (!(bmap_flags & BMAP_ALLOC)) {
377 if (bmap_flags & BMAP_SET)
378 retval = EXT2_ET_SET_BMAP_NO_IND;
382 b = inode_bmap(inode, EXT2_IND_BLOCK-1);
383 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
386 inode_bmap(inode, EXT2_IND_BLOCK) = b;
389 retval = block_ind_bmap(fs, bmap_flags, b, block_buf,
390 &blocks_alloc, block, &blk32);
396 /* Doubly indirect block */
397 block -= addr_per_block;
398 if (block < addr_per_block * addr_per_block) {
399 b = inode_bmap(inode, EXT2_DIND_BLOCK);
401 if (!(bmap_flags & BMAP_ALLOC)) {
402 if (bmap_flags & BMAP_SET)
403 retval = EXT2_ET_SET_BMAP_NO_IND;
407 b = inode_bmap(inode, EXT2_IND_BLOCK);
408 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
411 inode_bmap(inode, EXT2_DIND_BLOCK) = b;
414 retval = block_dind_bmap(fs, bmap_flags, b, block_buf,
415 &blocks_alloc, block, &blk32);
421 /* Triply indirect block */
422 block -= addr_per_block * addr_per_block;
423 b = inode_bmap(inode, EXT2_TIND_BLOCK);
425 if (!(bmap_flags & BMAP_ALLOC)) {
426 if (bmap_flags & BMAP_SET)
427 retval = EXT2_ET_SET_BMAP_NO_IND;
431 b = inode_bmap(inode, EXT2_DIND_BLOCK);
432 retval = ext2fs_alloc_block(fs, b, block_buf, &b);
435 inode_bmap(inode, EXT2_TIND_BLOCK) = b;
438 retval = block_tind_bmap(fs, bmap_flags, b, block_buf,
439 &blocks_alloc, block, &blk32);
444 ext2fs_free_mem(&buf);
446 ext2fs_extent_free(handle);
447 if ((retval == 0) && (blocks_alloc || inode_dirty)) {
448 ext2fs_iblk_add_blocks(fs, inode, blocks_alloc);
449 retval = ext2fs_write_inode(fs, ino, inode);
454 errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
455 char *block_buf, int bmap_flags, blk_t block,
459 blk64_t ret_blk = *phys_blk;
461 ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block,
465 if (ret_blk >= ((long long) 1 << 32))