diff options
Diffstat (limited to 'mkfs/super.c')
| -rw-r--r-- | mkfs/super.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/mkfs/super.c b/mkfs/super.c new file mode 100644 index 0000000..b3755d1 --- /dev/null +++ b/mkfs/super.c @@ -0,0 +1,126 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "mksquashfs.h" +#include "util.h" + +#include <endian.h> + +int sqfs_super_init(sqfs_super_t *s, const options_t *opt) +{ + unsigned int i; + + if (opt->blksz & (opt->blksz - 1)) { + fputs("Block size must be a power of 2!\n", stderr); + return -1; + } + + if (opt->blksz < 8192 || opt->blksz >= (1 << 24)) { + fputs("Block size must be between 8k and 1M\n", stderr); + return -1; + } + + memset(s, 0, sizeof(*s)); + s->magic = SQFS_MAGIC; + s->modification_time = opt->def_mtime; + s->block_size = opt->blksz; + s->compression_id = opt->compressor; + s->flags = SQFS_FLAG_NO_FRAGMENTS | SQFS_FLAG_NO_XATTRS; + s->version_major = SQFS_VERSION_MAJOR; + s->version_minor = SQFS_VERSION_MINOR; + s->bytes_used = sizeof(*s); + s->id_table_start = 0xFFFFFFFFFFFFFFFFUL; + s->xattr_id_table_start = 0xFFFFFFFFFFFFFFFFUL; + s->inode_table_start = 0xFFFFFFFFFFFFFFFFUL; + s->directory_table_start = 0xFFFFFFFFFFFFFFFFUL; + s->fragment_table_start = 0xFFFFFFFFFFFFFFFFUL; + s->export_table_start = 0xFFFFFFFFFFFFFFFFUL; + + for (i = opt->blksz; i != 0x01; i >>= 1) + s->block_log += 1; + + return 0; +} + +int sqfs_padd_file(sqfs_super_t *s, const options_t *opt, int outfd) +{ + size_t padd_sz = s->bytes_used % opt->devblksz; + uint8_t *buffer; + ssize_t ret; + + if (padd_sz == 0) + return 0; + + padd_sz = opt->devblksz - padd_sz; + + buffer = calloc(1, padd_sz); + if (buffer == NULL) { + perror("padding output file to block size"); + return -1; + } + + ret = write_retry(outfd, buffer, padd_sz); + + if (ret < 0) { + perror("Error padding squashfs image to page size"); + free(buffer); + return -1; + } + + if ((size_t)ret < padd_sz) { + fputs("Truncated write trying to padd squashfs image\n", + stderr); + return -1; + } + + free(buffer); + return 0; +} + +int sqfs_super_write(const sqfs_super_t *super, int outfd) +{ + sqfs_super_t copy; + ssize_t ret; + + copy.magic = htole32(super->magic); + copy.inode_count = htole32(super->inode_count); + copy.modification_time = htole32(super->modification_time); + copy.block_size = htole32(super->block_size); + copy.fragment_entry_count = htole32(super->fragment_entry_count); + copy.compression_id = htole16(super->compression_id); + copy.block_log = htole16(super->block_log); + copy.flags = htole16(super->flags); + copy.id_count = htole16(super->id_count); + copy.version_major = htole16(super->version_major); + copy.version_minor = htole16(super->version_minor); + copy.root_inode_ref = htole64(super->root_inode_ref); + copy.bytes_used = htole64(super->bytes_used); + copy.id_table_start = htole64(super->id_table_start); + copy.xattr_id_table_start = htole64(super->xattr_id_table_start); + copy.inode_table_start = htole64(super->inode_table_start); + copy.directory_table_start = htole64(super->directory_table_start); + copy.fragment_table_start = htole64(super->fragment_table_start); + copy.export_table_start = htole64(super->export_table_start); + + if (lseek(outfd, 0, SEEK_SET) == (off_t)-1) + goto fail_seek; + + ret = write_retry(outfd, ©, sizeof(copy)); + + if (ret < 0) { + perror("squashfs writing super block"); + return -1; + } + + if ((size_t)ret < sizeof(copy)) { + fputs("squashfs writing super block: truncated write\n", + stderr); + return -1; + } + + if (lseek(outfd, 0, SEEK_END) == (off_t)-1) + goto fail_seek; + + return 0; +fail_seek: + perror("squashfs writing super block: seek on output file"); + return -1; +} |