/* Functions for dealing with sparse files
- Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
oldgnu_store_sparse_info (file, &i,
blk->sparse_header.sp,
SPARSES_IN_SPARSE_HEADER);
- set_next_block_after (blk);
if (i < file->stat_info->sparse_map_avail)
blk->sparse_header.isextended = 1;
- else
- break;
+ set_next_block_after (blk);
}
return true;
}
};
\f
-/* GNU PAX sparse file format. The sparse file map is stored in
- x header:
+/* GNU PAX sparse file format. There are several versions:
+
+
+ * 0.0
+
+ The initial version of sparse format used by tar 1.14-1.15.1.
+ The sparse file map is stored in x header:
GNU.sparse.size Real size of the stored file
GNU.sparse.numblocks Number of blocks in the sparse map
- GNU.sparse.map Map of non-null data chunks. A string consisting
- of comma-separated values "offset,size[,offset,size]..."
-
- Tar versions 1.14-1.15.1 instead of the latter used:
-
repeat numblocks time
GNU.sparse.offset Offset of the next data block
GNU.sparse.numbytes Size of the next data block
This has been reported as conflicting with the POSIX specs. The reason is
that offsets and sizes of non-zero data blocks were stored in multiple
- instances of GNU.sparse.offset/GNU.sparse.numbytes variables. However,
+ instances of GNU.sparse.offset/GNU.sparse.numbytes variables, whereas
POSIX requires the latest occurrence of the variable to override all
previous occurrences.
-
- To avoid this incompatibility new keyword GNU.sparse.map was introduced
- in tar 1.15.2. Some people might still need the 1.14 way of handling
- sparse files for the compatibility reasons: it can be achieved by
- specifying `--pax-option delete=GNU.sparse.map' in the command line.
+
+ To avoid this incompatibility two following versions were introduced.
+
+ * 0.1
+
+ Used by tar 1.15.2 -- 1.15.91 (alpha releases).
+
+ The sparse file map is stored in
+ x header:
+
+ GNU.sparse.size Real size of the stored file
+ GNU.sparse.numblocks Number of blocks in the sparse map
+ GNU.sparse.map Map of non-null data chunks. A string consisting
+ of comma-separated values "offset,size[,offset,size]..."
+
+ The resulting GNU.sparse.map string can be *very* long. While POSIX does not
+ impose any limit on the length of a x header variable, this can confuse some
+ tars.
+
+ * 1.0
- See FIXME-1.14-1.15.1-1.20, below.
+ Starting from this version, the exact sparse format version is specified explicitely
+ in the header using the following variables:
+
+ GNU.sparse.major Major version
+ GNU.sparse.minor Minor version
+
+ X header keeps the following variables:
+
+ GNU.sparse.name Real file name of the sparse file
+ GNU.sparse.realsize Real size of the stored file (corresponds to the old
+ GNU.sparse.size variable)
+
+ The name field of the ustar header is constructed using the pattern
+ "%d/GNUSparseFile.%p/%f".
+
+ The sparse map itself is stored in the file data block, preceding the actual
+ file data. It consists of a series of octal numbers of arbitrary length, delimited
+ by newlines. The map is padded with nulls to the nearest block boundary.
+
+ The first number gives the number of entries in the map. Following are map entries,
+ each one consisting of two numbers giving the offset and size of the
+ data block it describes.
+
+ The format is designed in such a way that non-posix aware tars and tars not
+ supporting GNU.sparse.* keywords will extract each sparse file in its condensed
+ form with the file map attached and will place it into a separate directory.
+ Then, using a simple program it would be possible to expand the file to its
+ original form even without GNU tar.
+
+ Bu default, v.1.0 archives are created. To use other formats, --sparse-version
+ option is provided. Additionally, v.0.0 can be obtained by deleting GNU.sparse.map
+ from 0.1 format: --sparse-version 0.1 --pax-option delete=GNU.sparse.map
*/
static bool
pax_sparse_member_p (struct tar_sparse_file *file)
{
- return file->stat_info->sparse_map_avail > 0;
+ return file->stat_info->sparse_map_avail > 0
+ || file->stat_info->sparse_major > 0;
}
static bool
-pax_dump_header (struct tar_sparse_file *file)
+pax_dump_header_0 (struct tar_sparse_file *file)
{
off_t block_ordinal = current_block_ordinal ();
union block *blk;
xheader_store ("GNU.sparse.size", file->stat_info, NULL);
xheader_store ("GNU.sparse.numblocks", file->stat_info, NULL);
- /* FIXME-1.14-1.15.1-1.20: See the comment above.
- Starting with 1.17 this should display a warning about POSIX-incompatible
- keywords being generated. In 1.20, the true branch of the if block below
- will be removed and GNU.sparse.map will be marked in xhdr_tab as
- protected. */
-
- if (xheader_keyword_deleted_p ("GNU.sparse.map"))
+ if (xheader_keyword_deleted_p ("GNU.sparse.map")
+ || tar_sparse_minor == 0)
{
for (i = 0; i < file->stat_info->sparse_map_avail; i++)
{
return true;
}
+static bool
+pax_dump_header_1 (struct tar_sparse_file *file)
+{
+ off_t block_ordinal = current_block_ordinal ();
+ union block *blk;
+ char *p, *q;
+ size_t i;
+ char nbuf[UINTMAX_STRSIZE_BOUND];
+ off_t size = 0;
+ struct sp_array *map = file->stat_info->sparse_map;
+ char *save_file_name = file->stat_info->file_name;
+
+#define COPY_STRING(b,dst,src) do \
+ { \
+ char *endp = b->buffer + BLOCKSIZE; \
+ char *srcp = src; \
+ while (*srcp) \
+ { \
+ if (dst == endp) \
+ { \
+ set_next_block_after (b); \
+ b = find_next_block (); \
+ dst = b->buffer; \
+ endp = b->buffer + BLOCKSIZE; \
+ } \
+ *dst++ = *srcp++; \
+ } \
+ } while (0)
+
+ /* Compute stored file size */
+ p = umaxtostr (file->stat_info->sparse_map_avail, nbuf);
+ size += strlen (p) + 1;
+ for (i = 0; i < file->stat_info->sparse_map_avail; i++)
+ {
+ p = umaxtostr (map[i].offset, nbuf);
+ size += strlen (p) + 1;
+ p = umaxtostr (map[i].numbytes, nbuf);
+ size += strlen (p) + 1;
+ }
+ size = (size + BLOCKSIZE - 1) / BLOCKSIZE;
+ file->stat_info->archive_file_size += size * BLOCKSIZE;
+
+ /* Store sparse file identification */
+ xheader_store ("GNU.sparse.major", file->stat_info, NULL);
+ xheader_store ("GNU.sparse.minor", file->stat_info, NULL);
+ xheader_store ("GNU.sparse.name", file->stat_info, NULL);
+ xheader_store ("GNU.sparse.realsize", file->stat_info, NULL);
+
+ file->stat_info->file_name = xheader_format_name (file->stat_info,
+ "%d/GNUSparseFile.%p/%f", 0);
+
+ blk = start_header (file->stat_info);
+ /* Store the effective (shrunken) file size */
+ OFF_TO_CHARS (file->stat_info->archive_file_size, blk->header.size);
+ finish_header (file->stat_info, blk, block_ordinal);
+ free (file->stat_info->file_name);
+ file->stat_info->file_name = save_file_name;
+
+ blk = find_next_block ();
+ q = blk->buffer;
+ p = umaxtostr (file->stat_info->sparse_map_avail, nbuf);
+ COPY_STRING (blk, q, p);
+ COPY_STRING (blk, q, "\n");
+ for (i = 0; i < file->stat_info->sparse_map_avail; i++)
+ {
+ p = umaxtostr (map[i].offset, nbuf);
+ COPY_STRING (blk, q, p);
+ COPY_STRING (blk, q, "\n");
+ p = umaxtostr (map[i].numbytes, nbuf);
+ COPY_STRING (blk, q, p);
+ COPY_STRING (blk, q, "\n");
+ }
+ memset (q, 0, BLOCKSIZE - (q - blk->buffer));
+ set_next_block_after (blk);
+ return true;
+}
+
+static bool
+pax_dump_header (struct tar_sparse_file *file)
+{
+ file->stat_info->sparse_major = tar_sparse_major;
+ file->stat_info->sparse_minor = tar_sparse_minor;
+
+ if (file->stat_info->sparse_major == 0)
+ pax_dump_header_0 (file);
+ else
+ pax_dump_header_1 (file);
+}
+
+static bool
+decode_num (uintmax_t *num, char const *arg, uintmax_t maxval)
+{
+ uintmax_t u;
+ char *arg_lim;
+
+ if (!ISDIGIT (*arg))
+ return false;
+
+ u = strtoumax (arg, &arg_lim, 10);
+
+ if (! (u <= maxval && errno != ERANGE) || *arg_lim)
+ return false;
+
+ *num = u;
+ return true;
+}
+
+static bool
+pax_decode_header (struct tar_sparse_file *file)
+{
+ if (file->stat_info->sparse_major > 0)
+ {
+ uintmax_t u;
+ char nbuf[UINTMAX_STRSIZE_BOUND];
+ union block *blk;
+ char *p;
+ size_t i;
+
+#define COPY_BUF(b,buf,src) do \
+ { \
+ char *endp = b->buffer + BLOCKSIZE; \
+ char *dst = buf; \
+ do \
+ { \
+ if (dst == buf + UINTMAX_STRSIZE_BOUND -1) \
+ { \
+ ERROR ((0, 0, _("%s: numeric overflow in sparse archive member"), \
+ file->stat_info->orig_file_name)); \
+ return false; \
+ } \
+ if (src == endp) \
+ { \
+ set_next_block_after (b); \
+ b = find_next_block (); \
+ src = b->buffer; \
+ endp = b->buffer + BLOCKSIZE; \
+ } \
+ *dst = *src++; \
+ } \
+ while (*dst++ != '\n'); \
+ dst[-1] = 0; \
+ } while (0)
+
+ set_next_block_after (current_header);
+ blk = find_next_block ();
+ p = blk->buffer;
+ COPY_BUF (blk,nbuf,p);
+ if (!decode_num (&u, nbuf, TYPE_MAXIMUM (size_t)))
+ {
+ ERROR ((0, 0, _("%s: malformed sparse archive member"),
+ file->stat_info->orig_file_name));
+ return false;
+ }
+ file->stat_info->sparse_map_size = u;
+ file->stat_info->sparse_map = xcalloc (file->stat_info->sparse_map_size,
+ sizeof (*file->stat_info->sparse_map));
+ file->stat_info->sparse_map_avail = 0;
+ for (i = 0; i < file->stat_info->sparse_map_size; i++)
+ {
+ struct sp_array sp;
+
+ COPY_BUF (blk,nbuf,p);
+ if (!decode_num (&u, nbuf, TYPE_MAXIMUM (off_t)))
+ {
+ ERROR ((0, 0, _("%s: malformed sparse archive member"),
+ file->stat_info->orig_file_name));
+ return false;
+ }
+ sp.offset = u;
+ COPY_BUF (blk,nbuf,p);
+ if (!decode_num (&u, nbuf, TYPE_MAXIMUM (size_t)))
+ {
+ ERROR ((0, 0, _("%s: malformed sparse archive member"),
+ file->stat_info->orig_file_name));
+ return false;
+ }
+ sp.numbytes = u;
+ sparse_add_map (file->stat_info, &sp);
+ }
+ set_next_block_after (blk);
+ }
+
+ return true;
+}
+
static struct tar_sparse_optab const pax_optab = {
NULL, /* No init function */
NULL, /* No done function */
pax_sparse_member_p,
pax_dump_header,
- NULL, /* No decode_header function */
- NULL, /* No fixup_header function */
+ NULL,
+ pax_decode_header,
NULL, /* No scan_block function */
sparse_dump_region,
sparse_extract_region,
projects / chaz / tar / commitdiff
