| /* |
| * bmap.c --- logical to physical block mapping |
| * |
| * Copyright (C) 1997 Theodore Ts'o. |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the GNU Library |
| * General Public License, version 2. |
| * %End-Header% |
| */ |
| |
| #include "config.h" |
| #include <stdio.h> |
| #include <string.h> |
| #if HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #include <errno.h> |
| |
| #include "ext2_fs.h" |
| #include "ext2fsP.h" |
| |
| #if defined(__GNUC__) && !defined(NO_INLINE_FUNCS) |
| #define _BMAP_INLINE_ __inline__ |
| #else |
| #define _BMAP_INLINE_ |
| #endif |
| |
| extern errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, |
| struct ext2_inode *inode, |
| char *block_buf, int bmap_flags, |
| blk_t block, blk_t *phys_blk); |
| |
| #define inode_bmap(inode, nr) ((inode)->i_block[(nr)]) |
| |
| static _BMAP_INLINE_ errcode_t block_ind_bmap(ext2_filsys fs, int flags, |
| blk_t ind, char *block_buf, |
| int *blocks_alloc, |
| blk_t nr, blk_t *ret_blk) |
| { |
| errcode_t retval; |
| blk_t b; |
| |
| if (!ind) { |
| if (flags & BMAP_SET) |
| return EXT2_ET_SET_BMAP_NO_IND; |
| *ret_blk = 0; |
| return 0; |
| } |
| retval = io_channel_read_blk(fs->io, ind, 1, block_buf); |
| if (retval) |
| return retval; |
| |
| if (flags & BMAP_SET) { |
| b = *ret_blk; |
| #ifdef WORDS_BIGENDIAN |
| b = ext2fs_swab32(b); |
| #endif |
| ((blk_t *) block_buf)[nr] = b; |
| return io_channel_write_blk(fs->io, ind, 1, block_buf); |
| } |
| |
| b = ((blk_t *) block_buf)[nr]; |
| |
| #ifdef WORDS_BIGENDIAN |
| b = ext2fs_swab32(b); |
| #endif |
| |
| if (!b && (flags & BMAP_ALLOC)) { |
| b = nr ? ext2fs_le32_to_cpu(((blk_t *)block_buf)[nr - 1]) : ind; |
| retval = ext2fs_alloc_block(fs, b, |
| block_buf + fs->blocksize, &b); |
| if (retval) |
| return retval; |
| |
| #ifdef WORDS_BIGENDIAN |
| ((blk_t *) block_buf)[nr] = ext2fs_swab32(b); |
| #else |
| ((blk_t *) block_buf)[nr] = b; |
| #endif |
| |
| retval = io_channel_write_blk(fs->io, ind, 1, block_buf); |
| if (retval) |
| return retval; |
| |
| (*blocks_alloc)++; |
| } |
| |
| *ret_blk = b; |
| return 0; |
| } |
| |
| static _BMAP_INLINE_ errcode_t block_dind_bmap(ext2_filsys fs, int flags, |
| blk_t dind, char *block_buf, |
| int *blocks_alloc, |
| blk_t nr, blk_t *ret_blk) |
| { |
| blk_t b = 0; |
| errcode_t retval; |
| blk_t addr_per_block; |
| |
| addr_per_block = (blk_t) fs->blocksize >> 2; |
| |
| retval = block_ind_bmap(fs, flags & ~BMAP_SET, dind, block_buf, |
| blocks_alloc, nr / addr_per_block, &b); |
| if (retval) |
| return retval; |
| retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc, |
| nr % addr_per_block, ret_blk); |
| return retval; |
| } |
| |
| static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags, |
| blk_t tind, char *block_buf, |
| int *blocks_alloc, |
| blk_t nr, blk_t *ret_blk) |
| { |
| blk_t b = 0; |
| errcode_t retval; |
| blk_t addr_per_block; |
| |
| addr_per_block = (blk_t) fs->blocksize >> 2; |
| |
| retval = block_dind_bmap(fs, flags & ~BMAP_SET, tind, block_buf, |
| blocks_alloc, nr / addr_per_block, &b); |
| if (retval) |
| return retval; |
| retval = block_ind_bmap(fs, flags, b, block_buf, blocks_alloc, |
| nr % addr_per_block, ret_blk); |
| return retval; |
| } |
| |
| static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino, |
| struct ext2_inode *inode, |
| ext2_extent_handle_t handle, |
| char *block_buf, int bmap_flags, blk64_t block, |
| int *ret_flags, int *blocks_alloc, |
| blk64_t *phys_blk); |
| |
| static errcode_t implied_cluster_alloc(ext2_filsys fs, ext2_ino_t ino, |
| struct ext2_inode *inode, |
| ext2_extent_handle_t handle, |
| blk64_t lblk, blk64_t *phys_blk) |
| { |
| blk64_t base_block, pblock = 0; |
| int i; |
| |
| if (!ext2fs_has_feature_bigalloc(fs->super)) |
| return 0; |
| |
| base_block = lblk & ~EXT2FS_CLUSTER_MASK(fs); |
| /* |
| * Except for the logical block (lblk) that was passed in, search all |
| * blocks in this logical cluster for a mapping to a physical cluster. |
| * If any such map exists, calculate the physical block that maps to |
| * the logical block and return that. |
| * |
| * The old code wouldn't even look if (block % cluster_ratio) == 0; |
| * this is incorrect if we're allocating blocks in reverse order. |
| */ |
| for (i = 0; i < EXT2FS_CLUSTER_RATIO(fs); i++) { |
| if (base_block + i == lblk) |
| continue; |
| extent_bmap(fs, ino, inode, handle, 0, 0, |
| base_block + i, 0, 0, &pblock); |
| if (pblock) |
| break; |
| } |
| if (pblock == 0) |
| return 0; |
| *phys_blk = pblock - i + (lblk - base_block); |
| return 0; |
| } |
| |
| /* Try to map a logical block to an already-allocated physical cluster. */ |
| errcode_t ext2fs_map_cluster_block(ext2_filsys fs, ext2_ino_t ino, |
| struct ext2_inode *inode, blk64_t lblk, |
| blk64_t *pblk) |
| { |
| ext2_extent_handle_t handle; |
| errcode_t retval; |
| |
| /* Need bigalloc and extents to be enabled */ |
| *pblk = 0; |
| if (!ext2fs_has_feature_bigalloc(fs->super) || |
| !(inode->i_flags & EXT4_EXTENTS_FL)) |
| return 0; |
| |
| retval = ext2fs_extent_open2(fs, ino, inode, &handle); |
| if (retval) |
| goto out; |
| |
| retval = implied_cluster_alloc(fs, ino, inode, handle, lblk, pblk); |
| if (retval) |
| goto out2; |
| |
| out2: |
| ext2fs_extent_free(handle); |
| out: |
| return retval; |
| } |
| |
| static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino, |
| struct ext2_inode *inode, |
| ext2_extent_handle_t handle, |
| char *block_buf, int bmap_flags, blk64_t block, |
| int *ret_flags, int *blocks_alloc, |
| blk64_t *phys_blk) |
| { |
| struct blk_alloc_ctx alloc_ctx; |
| struct ext2fs_extent extent; |
| unsigned int offset; |
| errcode_t retval = 0; |
| blk64_t blk64 = 0; |
| int alloc = 0; |
| int set_flags; |
| |
| set_flags = bmap_flags & BMAP_UNINIT ? EXT2_EXTENT_SET_BMAP_UNINIT : 0; |
| |
| if (bmap_flags & BMAP_SET) { |
| retval = ext2fs_extent_set_bmap(handle, block, |
| *phys_blk, set_flags); |
| return retval; |
| } |
| retval = ext2fs_extent_goto(handle, block); |
| if (retval) { |
| /* If the extent is not found, return phys_blk = 0 */ |
| if (retval == EXT2_ET_EXTENT_NOT_FOUND) |
| goto got_block; |
| return retval; |
| } |
| retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent); |
| if (retval) |
| return retval; |
| offset = block - extent.e_lblk; |
| if (block >= extent.e_lblk && (offset <= extent.e_len)) { |
| *phys_blk = extent.e_pblk + offset; |
| if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT) |
| *ret_flags |= BMAP_RET_UNINIT; |
| } |
| got_block: |
| if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) { |
| implied_cluster_alloc(fs, ino, inode, handle, block, &blk64); |
| if (blk64) |
| goto set_extent; |
| retval = extent_bmap(fs, ino, inode, handle, block_buf, |
| 0, block-1, 0, blocks_alloc, &blk64); |
| if (retval) |
| blk64 = ext2fs_find_inode_goal(fs, ino, inode, block); |
| alloc_ctx.ino = ino; |
| alloc_ctx.inode = inode; |
| alloc_ctx.lblk = extent.e_lblk; |
| alloc_ctx.flags = BLOCK_ALLOC_DATA; |
| retval = ext2fs_alloc_block3(fs, blk64, block_buf, &blk64, |
| &alloc_ctx); |
| if (retval) |
| return retval; |
| blk64 &= ~EXT2FS_CLUSTER_MASK(fs); |
| blk64 += EXT2FS_CLUSTER_MASK(fs) & block; |
| alloc++; |
| set_extent: |
| retval = ext2fs_extent_set_bmap(handle, block, |
| blk64, set_flags); |
| if (retval) { |
| ext2fs_block_alloc_stats2(fs, blk64, -1); |
| return retval; |
| } |
| /* Update inode after setting extent */ |
| retval = ext2fs_read_inode(fs, ino, inode); |
| if (retval) |
| return retval; |
| *blocks_alloc += alloc; |
| *phys_blk = blk64; |
| } |
| return 0; |
| } |
| |
| int ext2fs_file_block_offset_too_big(ext2_filsys fs, |
| struct ext2_inode *inode, |
| blk64_t offset) |
| { |
| blk64_t addr_per_block, max_map_block; |
| |
| /* Kernel seems to cut us off at 4294967294 blocks */ |
| if (offset >= (1ULL << 32) - 1) |
| return 1; |
| |
| if (inode->i_flags & EXT4_EXTENTS_FL) |
| return 0; |
| |
| addr_per_block = fs->blocksize >> 2; |
| max_map_block = addr_per_block; |
| max_map_block += addr_per_block * addr_per_block; |
| max_map_block += addr_per_block * addr_per_block * addr_per_block; |
| max_map_block += 12; |
| |
| return offset >= max_map_block; |
| } |
| |
| errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, |
| char *block_buf, int bmap_flags, blk64_t block, |
| int *ret_flags, blk64_t *phys_blk) |
| { |
| struct ext2_inode inode_buf; |
| ext2_extent_handle_t handle = 0; |
| blk_t addr_per_block; |
| blk_t b, blk32; |
| blk64_t b64; |
| char *buf = 0; |
| errcode_t retval = 0; |
| int blocks_alloc = 0, inode_dirty = 0; |
| struct blk_alloc_ctx alloc_ctx = { |
| .ino = ino, |
| .inode = inode, |
| .lblk = 0, |
| .flags = BLOCK_ALLOC_DATA, |
| }; |
| |
| if (!(bmap_flags & BMAP_SET)) |
| *phys_blk = 0; |
| |
| if (ret_flags) |
| *ret_flags = 0; |
| |
| /* Read inode structure if necessary */ |
| if (!inode) { |
| retval = ext2fs_read_inode(fs, ino, &inode_buf); |
| if (retval) |
| return retval; |
| inode = &inode_buf; |
| } |
| addr_per_block = (blk_t) fs->blocksize >> 2; |
| |
| if (ext2fs_file_block_offset_too_big(fs, inode, block)) |
| return EXT2_ET_FILE_TOO_BIG; |
| |
| /* |
| * If an inode has inline data, that means that it doesn't have |
| * any blocks and we shouldn't map any blocks for it. |
| */ |
| if (inode->i_flags & EXT4_INLINE_DATA_FL) |
| return EXT2_ET_INLINE_DATA_NO_BLOCK; |
| |
| if (!block_buf) { |
| retval = ext2fs_get_array(2, fs->blocksize, &buf); |
| if (retval) |
| return retval; |
| block_buf = buf; |
| } |
| |
| if (inode->i_flags & EXT4_EXTENTS_FL) { |
| retval = ext2fs_extent_open2(fs, ino, inode, &handle); |
| if (retval) |
| goto done; |
| retval = extent_bmap(fs, ino, inode, handle, block_buf, |
| bmap_flags, block, ret_flags, |
| &blocks_alloc, phys_blk); |
| goto done; |
| } |
| |
| if (block < EXT2_NDIR_BLOCKS) { |
| if (bmap_flags & BMAP_SET) { |
| b = *phys_blk; |
| inode_bmap(inode, block) = b; |
| inode_dirty++; |
| goto done; |
| } |
| |
| *phys_blk = inode_bmap(inode, block); |
| b = block ? inode_bmap(inode, block - 1) : |
| ext2fs_find_inode_goal(fs, ino, inode, block); |
| |
| if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) { |
| b64 = b; |
| retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64, |
| &alloc_ctx); |
| b = b64; |
| if (retval) |
| goto done; |
| inode_bmap(inode, block) = b; |
| blocks_alloc++; |
| *phys_blk = b; |
| } |
| goto done; |
| } |
| |
| /* Indirect block */ |
| block -= EXT2_NDIR_BLOCKS; |
| blk32 = *phys_blk; |
| if (block < addr_per_block) { |
| b = inode_bmap(inode, EXT2_IND_BLOCK); |
| if (!b) { |
| if (!(bmap_flags & BMAP_ALLOC)) { |
| if (bmap_flags & BMAP_SET) |
| retval = EXT2_ET_SET_BMAP_NO_IND; |
| goto done; |
| } |
| |
| b = inode_bmap(inode, EXT2_IND_BLOCK-1); |
| b64 = b; |
| retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64, |
| &alloc_ctx); |
| b = b64; |
| if (retval) |
| goto done; |
| inode_bmap(inode, EXT2_IND_BLOCK) = b; |
| blocks_alloc++; |
| } |
| retval = block_ind_bmap(fs, bmap_flags, b, block_buf, |
| &blocks_alloc, block, &blk32); |
| if (retval == 0) |
| *phys_blk = blk32; |
| goto done; |
| } |
| |
| /* Doubly indirect block */ |
| block -= addr_per_block; |
| if (block < addr_per_block * addr_per_block) { |
| b = inode_bmap(inode, EXT2_DIND_BLOCK); |
| if (!b) { |
| if (!(bmap_flags & BMAP_ALLOC)) { |
| if (bmap_flags & BMAP_SET) |
| retval = EXT2_ET_SET_BMAP_NO_IND; |
| goto done; |
| } |
| |
| b = inode_bmap(inode, EXT2_IND_BLOCK); |
| b64 = b; |
| retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64, |
| &alloc_ctx); |
| b = b64; |
| if (retval) |
| goto done; |
| inode_bmap(inode, EXT2_DIND_BLOCK) = b; |
| blocks_alloc++; |
| } |
| retval = block_dind_bmap(fs, bmap_flags, b, block_buf, |
| &blocks_alloc, block, &blk32); |
| if (retval == 0) |
| *phys_blk = blk32; |
| goto done; |
| } |
| |
| /* Triply indirect block */ |
| block -= addr_per_block * addr_per_block; |
| b = inode_bmap(inode, EXT2_TIND_BLOCK); |
| if (!b) { |
| if (!(bmap_flags & BMAP_ALLOC)) { |
| if (bmap_flags & BMAP_SET) |
| retval = EXT2_ET_SET_BMAP_NO_IND; |
| goto done; |
| } |
| |
| b = inode_bmap(inode, EXT2_DIND_BLOCK); |
| b64 = b; |
| retval = ext2fs_alloc_block3(fs, b64, block_buf, &b64, |
| &alloc_ctx); |
| b = b64; |
| if (retval) |
| goto done; |
| inode_bmap(inode, EXT2_TIND_BLOCK) = b; |
| blocks_alloc++; |
| } |
| retval = block_tind_bmap(fs, bmap_flags, b, block_buf, |
| &blocks_alloc, block, &blk32); |
| if (retval == 0) |
| *phys_blk = blk32; |
| done: |
| if (*phys_blk && retval == 0 && (bmap_flags & BMAP_ZERO)) |
| retval = ext2fs_zero_blocks2(fs, *phys_blk, 1, NULL, NULL); |
| if (buf) |
| ext2fs_free_mem(&buf); |
| if (handle) |
| ext2fs_extent_free(handle); |
| if ((retval == 0) && (blocks_alloc || inode_dirty)) { |
| ext2fs_iblk_add_blocks(fs, inode, blocks_alloc); |
| retval = ext2fs_write_inode(fs, ino, inode); |
| } |
| return retval; |
| } |
| |
| errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, |
| char *block_buf, int bmap_flags, blk_t block, |
| blk_t *phys_blk) |
| { |
| errcode_t ret; |
| blk64_t ret_blk = *phys_blk; |
| |
| ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block, |
| 0, &ret_blk); |
| if (ret) |
| return ret; |
| if (ret_blk >= ((long long) 1 << 32)) |
| return EOVERFLOW; |
| *phys_blk = ret_blk; |
| return 0; |
| } |
