From 464df1d5e5ab1322e2dd0a7796939fff1aeefa9a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:49:25 +0200 Subject: Adding upstream version 1.47.0. Signed-off-by: Daniel Baumann --- lib/ext2fs/fileio.c | 666 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 666 insertions(+) create mode 100644 lib/ext2fs/fileio.c (limited to 'lib/ext2fs/fileio.c') diff --git a/lib/ext2fs/fileio.c b/lib/ext2fs/fileio.c new file mode 100644 index 0000000..818f7f0 --- /dev/null +++ b/lib/ext2fs/fileio.c @@ -0,0 +1,666 @@ +/* + * fileio.c --- Simple file I/O routines + * + * 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 +#include +#if HAVE_UNISTD_H +#include +#endif + +#include "ext2_fs.h" +#include "ext2fs.h" +#include "ext2fsP.h" + +struct ext2_file { + errcode_t magic; + ext2_filsys fs; + ext2_ino_t ino; + struct ext2_inode inode; + int flags; + __u64 pos; + blk64_t blockno; + blk64_t physblock; + char *buf; +}; + +struct block_entry { + blk64_t physblock; + unsigned char sha[EXT2FS_SHA512_LENGTH]; +}; +typedef struct block_entry *block_entry_t; + +#define BMAP_BUFFER (file->buf + fs->blocksize) + +errcode_t ext2fs_file_open2(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode *inode, + int flags, ext2_file_t *ret) +{ + ext2_file_t file; + errcode_t retval; + + /* + * Don't let caller create or open a file for writing if the + * filesystem is read-only. + */ + if ((flags & (EXT2_FILE_WRITE | EXT2_FILE_CREATE)) && + !(fs->flags & EXT2_FLAG_RW)) + return EXT2_ET_RO_FILSYS; + + retval = ext2fs_get_mem(sizeof(struct ext2_file), &file); + if (retval) + return retval; + + memset(file, 0, sizeof(struct ext2_file)); + file->magic = EXT2_ET_MAGIC_EXT2_FILE; + file->fs = fs; + file->ino = ino; + file->flags = flags & EXT2_FILE_MASK; + + if (inode) { + memcpy(&file->inode, inode, sizeof(struct ext2_inode)); + } else { + retval = ext2fs_read_inode(fs, ino, &file->inode); + if (retval) + goto fail; + } + + retval = ext2fs_get_array(3, fs->blocksize, &file->buf); + if (retval) + goto fail; + + *ret = file; + return 0; + +fail: + if (file->buf) + ext2fs_free_mem(&file->buf); + ext2fs_free_mem(&file); + return retval; +} + +errcode_t ext2fs_file_open(ext2_filsys fs, ext2_ino_t ino, + int flags, ext2_file_t *ret) +{ + return ext2fs_file_open2(fs, ino, NULL, flags, ret); +} + +/* + * This function returns the filesystem handle of a file from the structure + */ +ext2_filsys ext2fs_file_get_fs(ext2_file_t file) +{ + if (file->magic != EXT2_ET_MAGIC_EXT2_FILE) + return 0; + return file->fs; +} + +/* + * This function returns the pointer to the inode of a file from the structure + */ +struct ext2_inode *ext2fs_file_get_inode(ext2_file_t file) +{ + if (file->magic != EXT2_ET_MAGIC_EXT2_FILE) + return NULL; + return &file->inode; +} + +/* This function returns the inode number from the structure */ +ext2_ino_t ext2fs_file_get_inode_num(ext2_file_t file) +{ + if (file->magic != EXT2_ET_MAGIC_EXT2_FILE) + return 0; + return file->ino; +} + +/* + * This function flushes the dirty block buffer out to disk if + * necessary. + */ +errcode_t ext2fs_file_flush(ext2_file_t file) +{ + errcode_t retval; + ext2_filsys fs; + int ret_flags; + blk64_t dontcare; + + EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE); + fs = file->fs; + + if (!(file->flags & EXT2_FILE_BUF_VALID) || + !(file->flags & EXT2_FILE_BUF_DIRTY)) + return 0; + + /* Is this an uninit block? */ + if (file->physblock && file->inode.i_flags & EXT4_EXTENTS_FL) { + retval = ext2fs_bmap2(fs, file->ino, &file->inode, BMAP_BUFFER, + 0, file->blockno, &ret_flags, &dontcare); + if (retval) + return retval; + if (ret_flags & BMAP_RET_UNINIT) { + retval = ext2fs_bmap2(fs, file->ino, &file->inode, + BMAP_BUFFER, BMAP_SET, + file->blockno, 0, + &file->physblock); + if (retval) + return retval; + } + } + + /* + * OK, the physical block hasn't been allocated yet. + * Allocate it. + */ + if (!file->physblock) { + retval = ext2fs_bmap2(fs, file->ino, &file->inode, + BMAP_BUFFER, file->ino ? BMAP_ALLOC : 0, + file->blockno, 0, &file->physblock); + if (retval) + return retval; + } + + retval = io_channel_write_blk64(fs->io, file->physblock, 1, file->buf); + if (retval) + return retval; + + file->flags &= ~EXT2_FILE_BUF_DIRTY; + + return retval; +} + +/* + * This function synchronizes the file's block buffer and the current + * file position, possibly invalidating block buffer if necessary + */ +static errcode_t sync_buffer_position(ext2_file_t file) +{ + blk64_t b; + errcode_t retval; + + b = file->pos / file->fs->blocksize; + if (b != file->blockno) { + retval = ext2fs_file_flush(file); + if (retval) + return retval; + file->flags &= ~EXT2_FILE_BUF_VALID; + } + file->blockno = b; + return 0; +} + +/* + * This function loads the file's block buffer with valid data from + * the disk as necessary. + * + * If dontfill is true, then skip initializing the buffer since we're + * going to be replacing its entire contents anyway. If set, then the + * function basically only sets file->physblock and EXT2_FILE_BUF_VALID + */ +#define DONTFILL 1 +static errcode_t load_buffer(ext2_file_t file, int dontfill) +{ + ext2_filsys fs = file->fs; + errcode_t retval; + int ret_flags; + + if (!(file->flags & EXT2_FILE_BUF_VALID)) { + retval = ext2fs_bmap2(fs, file->ino, &file->inode, + BMAP_BUFFER, 0, file->blockno, &ret_flags, + &file->physblock); + if (retval) + return retval; + if (!dontfill) { + if (file->physblock && + !(ret_flags & BMAP_RET_UNINIT)) { + retval = io_channel_read_blk64(fs->io, + file->physblock, + 1, file->buf); + if (retval) + return retval; + } else + memset(file->buf, 0, fs->blocksize); + } + file->flags |= EXT2_FILE_BUF_VALID; + } + return 0; +} + + +errcode_t ext2fs_file_close(ext2_file_t file) +{ + errcode_t retval; + + EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE); + + retval = ext2fs_file_flush(file); + + if (file->buf) + ext2fs_free_mem(&file->buf); + ext2fs_free_mem(&file); + + return retval; +} + + +static errcode_t +ext2fs_file_read_inline_data(ext2_file_t file, void *buf, + unsigned int wanted, unsigned int *got) +{ + ext2_filsys fs; + errcode_t retval; + unsigned int count = 0; + size_t size; + + fs = file->fs; + retval = ext2fs_inline_data_get(fs, file->ino, &file->inode, + file->buf, &size); + if (retval) + return retval; + + if (file->pos >= size) + goto out; + + count = size - file->pos; + if (count > wanted) + count = wanted; + memcpy(buf, file->buf + file->pos, count); + file->pos += count; + buf = (char *) buf + count; + +out: + if (got) + *got = count; + return retval; +} + + +errcode_t ext2fs_file_read(ext2_file_t file, void *buf, + unsigned int wanted, unsigned int *got) +{ + ext2_filsys fs; + errcode_t retval = 0; + unsigned int start, c, count = 0; + __u64 left; + char *ptr = (char *) buf; + + EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE); + fs = file->fs; + + /* If an inode has inline data, things get complicated. */ + if (file->inode.i_flags & EXT4_INLINE_DATA_FL) + return ext2fs_file_read_inline_data(file, buf, wanted, got); + + while ((file->pos < EXT2_I_SIZE(&file->inode)) && (wanted > 0)) { + retval = sync_buffer_position(file); + if (retval) + goto fail; + retval = load_buffer(file, 0); + if (retval) + goto fail; + + start = file->pos % fs->blocksize; + c = fs->blocksize - start; + if (c > wanted) + c = wanted; + left = EXT2_I_SIZE(&file->inode) - file->pos ; + if (c > left) + c = left; + + memcpy(ptr, file->buf+start, c); + file->pos += c; + ptr += c; + count += c; + wanted -= c; + } + +fail: + if (got) + *got = count; + return retval; +} + + +static errcode_t +ext2fs_file_write_inline_data(ext2_file_t file, const void *buf, + unsigned int nbytes, unsigned int *written) +{ + ext2_filsys fs; + errcode_t retval; + unsigned int count = 0; + size_t size; + + fs = file->fs; + retval = ext2fs_inline_data_get(fs, file->ino, &file->inode, + file->buf, &size); + if (retval) + return retval; + + if (file->pos < size) { + count = nbytes - file->pos; + memcpy(file->buf + file->pos, buf, count); + + retval = ext2fs_inline_data_set(fs, file->ino, &file->inode, + file->buf, count); + if (retval == EXT2_ET_INLINE_DATA_NO_SPACE) + goto expand; + if (retval) + return retval; + + file->pos += count; + + /* Update inode size */ + if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos) { + errcode_t rc; + + rc = ext2fs_file_set_size2(file, file->pos); + if (retval == 0) + retval = rc; + } + + if (written) + *written = count; + return 0; + } + +expand: + retval = ext2fs_inline_data_expand(fs, file->ino); + if (retval) + return retval; + /* + * reload inode and return no space error + * + * XXX: file->inode could be copied from the outside + * in ext2fs_file_open2(). We have no way to modify + * the outside inode. + */ + retval = ext2fs_read_inode(fs, file->ino, &file->inode); + if (retval) + return retval; + return EXT2_ET_INLINE_DATA_NO_SPACE; +} + + +errcode_t ext2fs_file_write(ext2_file_t file, const void *buf, + unsigned int nbytes, unsigned int *written) +{ + ext2_filsys fs; + errcode_t retval = 0; + unsigned int start, c, count = 0; + const char *ptr = (const char *) buf; + block_entry_t new_block = NULL, old_block = NULL; + int bmap_flags = 0; + + EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE); + fs = file->fs; + + if (!(file->flags & EXT2_FILE_WRITE)) + return EXT2_ET_FILE_RO; + + /* If an inode has inline data, things get complicated. */ + if (file->inode.i_flags & EXT4_INLINE_DATA_FL) { + retval = ext2fs_file_write_inline_data(file, buf, nbytes, + written); + if (retval != EXT2_ET_INLINE_DATA_NO_SPACE) + return retval; + /* fall through to read data from the block */ + retval = 0; + } + + while (nbytes > 0) { + retval = sync_buffer_position(file); + if (retval) + goto fail; + + start = file->pos % fs->blocksize; + c = fs->blocksize - start; + if (c > nbytes) + c = nbytes; + + /* + * We only need to do a read-modify-update cycle if + * we're doing a partial write. + */ + retval = load_buffer(file, (c == fs->blocksize)); + if (retval) + goto fail; + + file->flags |= EXT2_FILE_BUF_DIRTY; + memcpy(file->buf+start, ptr, c); + + /* + * OK, the physical block hasn't been allocated yet. + * Allocate it. + */ + if (!file->physblock) { + bmap_flags = (file->ino ? BMAP_ALLOC : 0); + if (fs->flags & EXT2_FLAG_SHARE_DUP) { + new_block = calloc(1, sizeof(*new_block)); + if (!new_block) { + retval = EXT2_ET_NO_MEMORY; + goto fail; + } + ext2fs_sha512((const unsigned char*)file->buf, + fs->blocksize, new_block->sha); + old_block = ext2fs_hashmap_lookup( + fs->block_sha_map, + new_block->sha, + sizeof(new_block->sha)); + } + + if (old_block) { + file->physblock = old_block->physblock; + bmap_flags |= BMAP_SET; + free(new_block); + new_block = NULL; + } + + retval = ext2fs_bmap2(fs, file->ino, &file->inode, + BMAP_BUFFER, + bmap_flags, + file->blockno, 0, + &file->physblock); + if (retval) { + free(new_block); + new_block = NULL; + goto fail; + } + + if (new_block) { + new_block->physblock = file->physblock; + int ret = ext2fs_hashmap_add(fs->block_sha_map, + new_block, new_block->sha, + sizeof(new_block->sha)); + if (ret) { + retval = EXT2_ET_NO_MEMORY; + free(new_block); + goto fail; + } + } + + if (bmap_flags & BMAP_SET) { + ext2fs_iblk_add_blocks(fs, &file->inode, 1); + ext2fs_write_inode(fs, file->ino, &file->inode); + } + } + + file->pos += c; + ptr += c; + count += c; + nbytes -= c; + } + +fail: + /* Update inode size */ + if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos) { + errcode_t rc; + + rc = ext2fs_file_set_size2(file, file->pos); + if (retval == 0) + retval = rc; + } + + if (written) + *written = count; + return retval; +} + +errcode_t ext2fs_file_llseek(ext2_file_t file, __u64 offset, + int whence, __u64 *ret_pos) +{ + EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE); + + if (whence == EXT2_SEEK_SET) + file->pos = offset; + else if (whence == EXT2_SEEK_CUR) + file->pos += offset; + else if (whence == EXT2_SEEK_END) + file->pos = EXT2_I_SIZE(&file->inode) + offset; + else + return EXT2_ET_INVALID_ARGUMENT; + + if (ret_pos) + *ret_pos = file->pos; + + return 0; +} + +errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset, + int whence, ext2_off_t *ret_pos) +{ + __u64 loffset, ret_loffset = 0; + errcode_t retval; + + loffset = offset; + retval = ext2fs_file_llseek(file, loffset, whence, &ret_loffset); + if (ret_pos) + *ret_pos = (ext2_off_t) ret_loffset; + return retval; +} + + +/* + * This function returns the size of the file, according to the inode + */ +errcode_t ext2fs_file_get_lsize(ext2_file_t file, __u64 *ret_size) +{ + if (file->magic != EXT2_ET_MAGIC_EXT2_FILE) + return EXT2_ET_MAGIC_EXT2_FILE; + *ret_size = EXT2_I_SIZE(&file->inode); + return 0; +} + +/* + * This function returns the size of the file, according to the inode + */ +ext2_off_t ext2fs_file_get_size(ext2_file_t file) +{ + __u64 size; + + if (ext2fs_file_get_lsize(file, &size)) + return 0; + if ((size >> 32) != 0) + return 0; + return size; +} + +/* Zero the parts of the last block that are past EOF. */ +static errcode_t ext2fs_file_zero_past_offset(ext2_file_t file, + ext2_off64_t offset) +{ + ext2_filsys fs = file->fs; + char *b = NULL; + ext2_off64_t off = offset % fs->blocksize; + blk64_t blk; + int ret_flags; + errcode_t retval; + + if (off == 0) + return 0; + + retval = sync_buffer_position(file); + if (retval) + return retval; + + /* Is there an initialized block at the end? */ + retval = ext2fs_bmap2(fs, file->ino, NULL, NULL, 0, + offset / fs->blocksize, &ret_flags, &blk); + if (retval) + return retval; + if ((blk == 0) || (ret_flags & BMAP_RET_UNINIT)) + return 0; + + /* Zero to the end of the block */ + retval = ext2fs_get_mem(fs->blocksize, &b); + if (retval) + return retval; + + /* Read/zero/write block */ + retval = io_channel_read_blk64(fs->io, blk, 1, b); + if (retval) + goto out; + + memset(b + off, 0, fs->blocksize - off); + + retval = io_channel_write_blk64(fs->io, blk, 1, b); + if (retval) + goto out; + +out: + ext2fs_free_mem(&b); + return retval; +} + +/* + * This function sets the size of the file, truncating it if necessary + * + */ +errcode_t ext2fs_file_set_size2(ext2_file_t file, ext2_off64_t size) +{ + ext2_off64_t old_size; + errcode_t retval; + blk64_t old_truncate, truncate_block; + + EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE); + + if (size && ext2fs_file_block_offset_too_big(file->fs, &file->inode, + (size - 1) / file->fs->blocksize)) + return EXT2_ET_FILE_TOO_BIG; + truncate_block = ((size + file->fs->blocksize - 1) >> + EXT2_BLOCK_SIZE_BITS(file->fs->super)); + old_size = EXT2_I_SIZE(&file->inode); + old_truncate = ((old_size + file->fs->blocksize - 1) >> + EXT2_BLOCK_SIZE_BITS(file->fs->super)); + + retval = ext2fs_inode_size_set(file->fs, &file->inode, size); + if (retval) + return retval; + + if (file->ino) { + retval = ext2fs_write_inode(file->fs, file->ino, &file->inode); + if (retval) + return retval; + } + + retval = ext2fs_file_zero_past_offset(file, size); + if (retval) + return retval; + + if (truncate_block >= old_truncate) + return 0; + + return ext2fs_punch(file->fs, file->ino, &file->inode, 0, + truncate_block, ~0ULL); +} + +errcode_t ext2fs_file_set_size(ext2_file_t file, ext2_off_t size) +{ + return ext2fs_file_set_size2(file, size); +} -- cgit v1.2.3