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-rw-r--r--include/data_reader.h6
-rw-r--r--lib/sqfs/data_reader.c20
-rw-r--r--tar/sqfs2tar.c2
-rw-r--r--unpack/options.c8
-rw-r--r--unpack/rdsquashfs.c3
-rw-r--r--unpack/rdsquashfs.h1
-rw-r--r--unpack/restore_fstree.c3
7 files changed, 37 insertions, 6 deletions
diff --git a/include/data_reader.h b/include/data_reader.h
index 68788b4..7de8e1a 100644
--- a/include/data_reader.h
+++ b/include/data_reader.h
@@ -26,8 +26,12 @@ void data_reader_destroy(data_reader_t *data);
file and its fragment, if it has one. The entire data is dumped to the
given file descriptor.
+ If allow_sparse is true, try to truncate and seek forward on outfd if a
+ zero block is found. If false, always write blocks of zeros to outfd.
+
Returns 0 on success, prints error messages to stderr on failure.
*/
-int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd);
+int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd,
+ bool allow_sparse);
#endif /* DATA_READER_H */
diff --git a/lib/sqfs/data_reader.c b/lib/sqfs/data_reader.c
index 421d914..f8c80af 100644
--- a/lib/sqfs/data_reader.c
+++ b/lib/sqfs/data_reader.c
@@ -59,7 +59,8 @@ void data_reader_destroy(data_reader_t *data)
free(data);
}
-int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd)
+int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd,
+ bool allow_sparse)
{
size_t i, count, fragsz;
bool compressed;
@@ -82,6 +83,14 @@ int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd)
if (bs > data->block_size)
goto fail_bs;
+ if (bs == 0 && allow_sparse) {
+ if (ftruncate(outfd, i * data->block_size))
+ goto fail_sparse;
+ if (lseek(outfd, 0, SEEK_END) == (off_t)-1)
+ goto fail_sparse;
+ continue;
+ }
+
if (bs == 0) {
bs = data->block_size;
memset(data->buffer, 0, bs);
@@ -123,6 +132,12 @@ int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd)
if (fragsz > 0) {
if (fi->fragment == 0xFFFFFFFF ||
fi->fragment_offset == 0xFFFFFFFF) {
+ if (allow_sparse) {
+ if (ftruncate(outfd, fragsz))
+ goto fail_sparse;
+ return 0;
+ }
+
memset(data->buffer, 0, fragsz);
} else {
if (data->frag == NULL)
@@ -144,6 +159,9 @@ int data_reader_dump_file(data_reader_t *data, file_info_t *fi, int outfd)
}
return 0;
+fail_sparse:
+ perror("creating sparse output file");
+ return -1;
fail_seek:
perror("seek on squashfs");
return -1;
diff --git a/tar/sqfs2tar.c b/tar/sqfs2tar.c
index 1be1b7e..e8b8736 100644
--- a/tar/sqfs2tar.c
+++ b/tar/sqfs2tar.c
@@ -131,7 +131,7 @@ static int write_tree_dfs(fstree_t *fs, tree_node_t *n, data_reader_t *data)
if (S_ISREG(n->mode)) {
if (data_reader_dump_file(data, n->data.file,
- STDOUT_FILENO)) {
+ STDOUT_FILENO, false)) {
return -1;
}
diff --git a/unpack/options.c b/unpack/options.c
index 84c17cf..c42f16a 100644
--- a/unpack/options.c
+++ b/unpack/options.c
@@ -11,6 +11,7 @@ static struct option long_opts[] = {
{ "no-fifo", no_argument, NULL, 'F' },
{ "no-slink", no_argument, NULL, 'L' },
{ "no-empty-dir", no_argument, NULL, 'E' },
+ { "no-sparse", no_argument, NULL, 'Z' },
{ "describe", no_argument, NULL, 'd' },
{ "chmod", no_argument, NULL, 'C' },
{ "chown", no_argument, NULL, 'O' },
@@ -19,7 +20,7 @@ static struct option long_opts[] = {
{ "version", no_argument, NULL, 'V' },
};
-static const char *short_opts = "l:c:u:p:DSFLCOEdqhV";
+static const char *short_opts = "l:c:u:p:DSFLCOEZdqhV";
static const char *help_string =
"Usage: %s [OPTIONS] <squashfs-file>\n"
@@ -47,6 +48,8 @@ static const char *help_string =
" --no-slink, -L Do not unpack symbolic links.\n"
" --no-empty-dir, -E Do not unpack directories that would end up\n"
" empty after applying the above rules.\n"
+" --no-sparse, -Z Do not create sparse files, always write zero\n"
+" blocks to disk.\n"
" --chmod, -C Change permission flags of unpacked files to\n"
" those store in the squashfs image.\n"
" --chown, -O Change ownership of unpacked files to the\n"
@@ -118,6 +121,9 @@ void process_command_line(options_t *opt, int argc, char **argv)
case 'O':
opt->flags |= UNPACK_CHOWN;
break;
+ case 'Z':
+ opt->flags |= UNPACK_NO_SPARSE;
+ break;
case 'c':
opt->op = OP_CAT;
opt->cmdpath = get_path(opt->cmdpath, optarg);
diff --git a/unpack/rdsquashfs.c b/unpack/rdsquashfs.c
index fcfc9c9..42bddff 100644
--- a/unpack/rdsquashfs.c
+++ b/unpack/rdsquashfs.c
@@ -100,7 +100,8 @@ int main(int argc, char **argv)
if (data == NULL)
goto out_fs;
- if (data_reader_dump_file(data, n->data.file, STDOUT_FILENO))
+ if (data_reader_dump_file(data, n->data.file,
+ STDOUT_FILENO, false))
goto out_fs;
break;
case OP_UNPACK:
diff --git a/unpack/rdsquashfs.h b/unpack/rdsquashfs.h
index 9d1ab4f..0ee48fa 100644
--- a/unpack/rdsquashfs.h
+++ b/unpack/rdsquashfs.h
@@ -24,6 +24,7 @@ enum UNPACK_FLAGS {
UNPACK_CHMOD = 0x01,
UNPACK_CHOWN = 0x02,
UNPACK_QUIET = 0x04,
+ UNPACK_NO_SPARSE = 0x08,
};
enum {
diff --git a/unpack/restore_fstree.c b/unpack/restore_fstree.c
index 976b15c..ab10f5d 100644
--- a/unpack/restore_fstree.c
+++ b/unpack/restore_fstree.c
@@ -63,7 +63,8 @@ static int create_node(tree_node_t *n, data_reader_t *data, int flags)
return -1;
}
- if (data_reader_dump_file(data, n->data.file, fd)) {
+ if (data_reader_dump_file(data, n->data.file, fd,
+ (flags & UNPACK_NO_SPARSE) == 0)) {
close(fd);
return -1;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 03:26:42 +0000