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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:49:25 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:49:25 +0000
commit464df1d5e5ab1322e2dd0a7796939fff1aeefa9a (patch)
tree6a403684e0978f0287d7f0ec0e5aab1fd31a59e1 /lib/ext2fs/bmap.c
parentInitial commit. (diff)
downloade2fsprogs-upstream/1.47.0.tar.xz
e2fsprogs-upstream/1.47.0.zip
Adding upstream version 1.47.0.upstream/1.47.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/ext2fs/bmap.c')
-rw-r--r--lib/ext2fs/bmap.c499
1 files changed, 499 insertions, 0 deletions
diff --git a/lib/ext2fs/bmap.c b/lib/ext2fs/bmap.c
new file mode 100644
index 0000000..65c45c5
--- /dev/null
+++ b/lib/ext2fs/bmap.c
@@ -0,0 +1,499 @@
+/*
+ * 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) {
+ extent.e_lblk = block;
+ 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;
+}