X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=src%2Fsparse.c;h=6a976763419e78a5d5041fe3a01046e787dccdc8;hb=9df17e6005e7a333399e3dc21a7afec75565c767;hp=bb1a180205b589b06eee3e4664996ba184f95b7c;hpb=6522c25b8d5260ab69338217f67403fc5bf3cd8a;p=chaz%2Ftar
diff --git a/src/sparse.c b/src/sparse.c
index bb1a180..6a97676 100644
--- a/src/sparse.c
+++ b/src/sparse.c
@@ -1,10 +1,10 @@
/* Functions for dealing with sparse files
- Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ Copyright 2003-2007, 2010, 2013-2014 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
- Free Software Foundation; either version 2, or (at your option) any later
+ Free Software Foundation; either version 3, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but
@@ -13,14 +13,15 @@
Public License for more details.
You should have received a copy of the GNU General Public License along
- with this program; if not, write to the Free Software Foundation, Inc.,
- 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ with this program. If not, see . */
-#include "system.h"
+#include
+#include
#include
#include "common.h"
struct tar_sparse_file;
+static bool sparse_select_optab (struct tar_sparse_file *file);
enum sparse_scan_state
{
@@ -46,14 +47,50 @@ struct tar_sparse_optab
struct tar_sparse_file
{
int fd; /* File descriptor */
- size_t dumped_size; /* Number of bytes actually written
+ bool seekable; /* Is fd seekable? */
+ off_t offset; /* Current offset in fd if seekable==false.
+ Otherwise unused */
+ off_t dumped_size; /* Number of bytes actually written
to the archive */
struct tar_stat_info *stat_info; /* Information about the file */
- struct tar_sparse_optab *optab;
+ struct tar_sparse_optab const *optab; /* Operation table */
void *closure; /* Any additional data optab calls might
- reqiure */
+ require */
};
+/* Dump zeros to file->fd until offset is reached. It is used instead of
+ lseek if the output file is not seekable */
+static bool
+dump_zeros (struct tar_sparse_file *file, off_t offset)
+{
+ static char const zero_buf[BLOCKSIZE];
+
+ if (offset < file->offset)
+ {
+ errno = EINVAL;
+ return false;
+ }
+
+ while (file->offset < offset)
+ {
+ size_t size = (BLOCKSIZE < offset - file->offset
+ ? BLOCKSIZE
+ : offset - file->offset);
+ ssize_t wrbytes;
+
+ wrbytes = write (file->fd, zero_buf, size);
+ if (wrbytes <= 0)
+ {
+ if (wrbytes == 0)
+ errno = EINVAL;
+ return false;
+ }
+ file->offset += wrbytes;
+ }
+
+ return true;
+}
+
static bool
tar_sparse_member_p (struct tar_sparse_file *file)
{
@@ -65,9 +102,14 @@ tar_sparse_member_p (struct tar_sparse_file *file)
static bool
tar_sparse_init (struct tar_sparse_file *file)
{
- file->dumped_size = 0;
+ memset (file, 0, sizeof *file);
+
+ if (!sparse_select_optab (file))
+ return false;
+
if (file->optab->init)
return file->optab->init (file);
+
return true;
}
@@ -130,9 +172,11 @@ tar_sparse_fixup_header (struct tar_sparse_file *file)
static bool
-lseek_or_error (struct tar_sparse_file *file, off_t offset, int whence)
+lseek_or_error (struct tar_sparse_file *file, off_t offset)
{
- if (lseek (file->fd, offset, whence) < 0)
+ if (file->seekable
+ ? lseek (file->fd, offset, SEEK_SET) < 0
+ : ! dump_zeros (file, offset))
{
seek_diag_details (file->stat_info->orig_file_name, offset);
return false;
@@ -144,7 +188,7 @@ lseek_or_error (struct tar_sparse_file *file, off_t offset, int whence)
it's made *entirely* of zeros, returning a 0 the instant it finds
something that is a nonzero, i.e., useful data. */
static bool
-zero_block_p (char *buffer, size_t size)
+zero_block_p (char const *buffer, size_t size)
{
while (size--)
if (*buffer++)
@@ -152,88 +196,77 @@ zero_block_p (char *buffer, size_t size)
return true;
}
-#define clear_block(p) memset (p, 0, BLOCKSIZE);
-
-#define SPARSES_INIT_COUNT SPARSES_IN_SPARSE_HEADER
-
static void
-sparse_add_map (struct tar_sparse_file *file, struct sp_array *sp)
+sparse_add_map (struct tar_stat_info *st, struct sp_array const *sp)
{
- if (file->stat_info->sparse_map == NULL)
- {
- file->stat_info->sparse_map =
- xmalloc (SPARSES_INIT_COUNT * sizeof file->stat_info->sparse_map[0]);
- file->stat_info->sparse_map_size = SPARSES_INIT_COUNT;
- }
- else if (file->stat_info->sparse_map_avail == file->stat_info->sparse_map_size)
- {
- file->stat_info->sparse_map_size *= 2;
- file->stat_info->sparse_map =
- xrealloc (file->stat_info->sparse_map,
- file->stat_info->sparse_map_size
- * sizeof file->stat_info->sparse_map[0]);
- }
- file->stat_info->sparse_map[file->stat_info->sparse_map_avail++] = *sp;
+ struct sp_array *sparse_map = st->sparse_map;
+ size_t avail = st->sparse_map_avail;
+ if (avail == st->sparse_map_size)
+ st->sparse_map = sparse_map =
+ x2nrealloc (sparse_map, &st->sparse_map_size, sizeof *sparse_map);
+ sparse_map[avail] = *sp;
+ st->sparse_map_avail = avail + 1;
}
/* Scan the sparse file and create its map */
static bool
sparse_scan_file (struct tar_sparse_file *file)
{
- static char buffer[BLOCKSIZE];
- size_t count;
- size_t offset = 0;
+ struct tar_stat_info *st = file->stat_info;
+ int fd = file->fd;
+ char buffer[BLOCKSIZE];
+ size_t count = 0;
+ off_t offset = 0;
struct sp_array sp = {0, 0};
- if (!lseek_or_error (file, 0, SEEK_SET))
- return false;
- clear_block (buffer);
+ st->archive_file_size = 0;
- file->stat_info->sparse_map_avail = 0;
- file->stat_info->archive_file_size = 0;
-
- if (!tar_sparse_scan (file, scan_begin, NULL))
- return false;
-
- while ((count = safe_read (file->fd, buffer, sizeof buffer)) != 0
- && count != SAFE_READ_ERROR)
+ if (ST_NBLOCKS (st->stat) == 0)
+ offset = st->stat.st_size;
+ else
{
- /* Analize the block */
- if (zero_block_p (buffer, count))
+ if (!tar_sparse_scan (file, scan_begin, NULL))
+ return false;
+
+ while ((count = blocking_read (fd, buffer, sizeof buffer)) != 0
+ && count != SAFE_READ_ERROR)
{
- if (sp.numbytes)
+ /* Analyze the block. */
+ if (zero_block_p (buffer, count))
+ {
+ if (sp.numbytes)
+ {
+ sparse_add_map (st, &sp);
+ sp.numbytes = 0;
+ if (!tar_sparse_scan (file, scan_block, NULL))
+ return false;
+ }
+ }
+ else
{
- sparse_add_map (file, &sp);
- sp.numbytes = 0;
- if (!tar_sparse_scan (file, scan_block, NULL))
+ if (sp.numbytes == 0)
+ sp.offset = offset;
+ sp.numbytes += count;
+ st->archive_file_size += count;
+ if (!tar_sparse_scan (file, scan_block, buffer))
return false;
}
- }
- else
- {
- if (sp.numbytes == 0)
- sp.offset = offset;
- sp.numbytes += count;
- file->stat_info->archive_file_size += count;
- if (!tar_sparse_scan (file, scan_block, buffer))
- return false;
- }
- offset += count;
- clear_block (buffer);
+ offset += count;
+ }
}
if (sp.numbytes == 0)
sp.offset = offset;
- sparse_add_map (file, &sp);
- file->stat_info->archive_file_size += count;
+ sparse_add_map (st, &sp);
+ st->archive_file_size += count;
return tar_sparse_scan (file, scan_end, NULL);
}
-static struct tar_sparse_optab oldgnu_optab;
-static struct tar_sparse_optab star_optab;
-static struct tar_sparse_optab pax_optab;
+static struct tar_sparse_optab const oldgnu_optab;
+static struct tar_sparse_optab const star_optab;
+static struct tar_sparse_optab const pax_optab;
static bool
sparse_select_optab (struct tar_sparse_file *file)
@@ -269,8 +302,7 @@ sparse_dump_region (struct tar_sparse_file *file, size_t i)
union block *blk;
off_t bytes_left = file->stat_info->sparse_map[i].numbytes;
- if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset,
- SEEK_SET))
+ if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset))
return false;
while (bytes_left > 0)
@@ -279,18 +311,18 @@ sparse_dump_region (struct tar_sparse_file *file, size_t i)
size_t bytes_read;
blk = find_next_block ();
- memset (blk->buffer, 0, BLOCKSIZE);
bytes_read = safe_read (file->fd, blk->buffer, bufsize);
if (bytes_read == SAFE_READ_ERROR)
{
read_diag_details (file->stat_info->orig_file_name,
- file->stat_info->sparse_map[i].offset
- + file->stat_info->sparse_map[i].numbytes
- - bytes_left,
- bufsize);
+ (file->stat_info->sparse_map[i].offset
+ + file->stat_info->sparse_map[i].numbytes
+ - bytes_left),
+ bufsize);
return false;
}
+ memset (blk->buffer + bytes_read, 0, BLOCKSIZE - bytes_read);
bytes_left -= bytes_read;
file->dumped_size += bytes_read;
set_next_block_after (blk);
@@ -302,10 +334,9 @@ sparse_dump_region (struct tar_sparse_file *file, size_t i)
static bool
sparse_extract_region (struct tar_sparse_file *file, size_t i)
{
- size_t write_size;
+ off_t write_size;
- if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset,
- SEEK_SET))
+ if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset))
return false;
write_size = file->stat_info->sparse_map[i].numbytes;
@@ -313,7 +344,7 @@ sparse_extract_region (struct tar_sparse_file *file, size_t i)
if (write_size == 0)
{
/* Last block of the file is a hole */
- if (sys_truncate (file->fd))
+ if (file->seekable && sys_truncate (file->fd))
truncate_warn (file->stat_info->orig_file_name);
}
else while (write_size > 0)
@@ -327,9 +358,11 @@ sparse_extract_region (struct tar_sparse_file *file, size_t i)
return false;
}
set_next_block_after (blk);
- count = full_write (file->fd, blk->buffer, wrbytes);
+ count = blocking_write (file->fd, blk->buffer, wrbytes);
write_size -= count;
file->dumped_size += count;
+ mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
+ file->offset += count;
if (count != wrbytes)
{
write_error_details (file->stat_info->orig_file_name,
@@ -349,12 +382,12 @@ sparse_dump_file (int fd, struct tar_stat_info *st)
bool rc;
struct tar_sparse_file file;
+ if (!tar_sparse_init (&file))
+ return dump_status_not_implemented;
+
file.stat_info = st;
file.fd = fd;
-
- if (!sparse_select_optab (&file)
- || !tar_sparse_init (&file))
- return dump_status_not_implemented;
+ file.seekable = true; /* File *must* be seekable for dump to work */
rc = sparse_scan_file (&file);
if (rc && file.optab->dump_region)
@@ -365,30 +398,24 @@ sparse_dump_file (int fd, struct tar_stat_info *st)
{
size_t i;
+ mv_begin_write (file.stat_info->file_name,
+ file.stat_info->stat.st_size,
+ file.stat_info->archive_file_size - file.dumped_size);
for (i = 0; rc && i < file.stat_info->sparse_map_avail; i++)
rc = tar_sparse_dump_region (&file, i);
}
}
- pad_archive(file.stat_info->archive_file_size - file.dumped_size);
+ pad_archive (file.stat_info->archive_file_size - file.dumped_size);
return (tar_sparse_done (&file) && rc) ? dump_status_ok : dump_status_short;
}
-/* Returns true if the file represented by stat is a sparse one */
-bool
-sparse_file_p (struct tar_stat_info *st)
-{
- return (ST_NBLOCKS (st->stat)
- < (st->stat.st_size / ST_NBLOCKSIZE
- + (st->stat.st_size % ST_NBLOCKSIZE != 0)));
-}
-
bool
sparse_member_p (struct tar_stat_info *st)
{
struct tar_sparse_file file;
- if (!sparse_select_optab (&file))
+ if (!tar_sparse_init (&file))
return false;
file.stat_info = st;
return tar_sparse_member_p (&file);
@@ -399,7 +426,7 @@ sparse_fixup_header (struct tar_stat_info *st)
{
struct tar_sparse_file file;
- if (!sparse_select_optab (&file))
+ if (!tar_sparse_init (&file))
return false;
file.stat_info = st;
return tar_sparse_fixup_header (&file);
@@ -412,12 +439,13 @@ sparse_extract_file (int fd, struct tar_stat_info *st, off_t *size)
struct tar_sparse_file file;
size_t i;
+ if (!tar_sparse_init (&file))
+ return dump_status_not_implemented;
+
file.stat_info = st;
file.fd = fd;
-
- if (!sparse_select_optab (&file)
- || !tar_sparse_init (&file))
- return dump_status_not_implemented;
+ file.seekable = lseek (fd, 0, SEEK_SET) == 0;
+ file.offset = 0;
rc = tar_sparse_decode_header (&file);
for (i = 0; rc && i < file.stat_info->sparse_map_avail; i++)
@@ -432,35 +460,30 @@ sparse_skip_file (struct tar_stat_info *st)
bool rc = true;
struct tar_sparse_file file;
+ if (!tar_sparse_init (&file))
+ return dump_status_not_implemented;
+
file.stat_info = st;
file.fd = -1;
- if (!sparse_select_optab (&file)
- || !tar_sparse_init (&file))
- return dump_status_not_implemented;
-
rc = tar_sparse_decode_header (&file);
- skip_file (file.stat_info->archive_file_size);
+ skip_file (file.stat_info->archive_file_size - file.dumped_size);
return (tar_sparse_done (&file) && rc) ? dump_status_ok : dump_status_short;
}
-static char diff_buffer[BLOCKSIZE];
-
static bool
check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
{
- if (!lseek_or_error (file, beg, SEEK_SET))
+ if (!lseek_or_error (file, beg))
return false;
while (beg < end)
{
size_t bytes_read;
- size_t rdsize = end - beg;
+ size_t rdsize = BLOCKSIZE < end - beg ? BLOCKSIZE : end - beg;
+ char diff_buffer[BLOCKSIZE];
- if (rdsize > BLOCKSIZE)
- rdsize = BLOCKSIZE;
- clear_block (diff_buffer);
bytes_read = safe_read (file->fd, diff_buffer, rdsize);
if (bytes_read == SAFE_READ_ERROR)
{
@@ -471,8 +494,10 @@ check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
}
if (!zero_block_p (diff_buffer, bytes_read))
{
+ char begbuf[INT_BUFSIZE_BOUND (off_t)];
report_difference (file->stat_info,
- _("File fragment at %lu is not a hole"), beg);
+ _("File fragment at %s is not a hole"),
+ offtostr (beg, begbuf));
return false;
}
@@ -484,16 +509,18 @@ check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
static bool
check_data_region (struct tar_sparse_file *file, size_t i)
{
- size_t size_left;
+ off_t size_left;
- if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset,
- SEEK_SET))
+ if (!lseek_or_error (file, file->stat_info->sparse_map[i].offset))
return false;
size_left = file->stat_info->sparse_map[i].numbytes;
+ mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
+
while (size_left > 0)
{
size_t bytes_read;
size_t rdsize = (size_left > BLOCKSIZE) ? BLOCKSIZE : size_left;
+ char diff_buffer[BLOCKSIZE];
union block *blk = find_next_block ();
if (!blk)
@@ -506,14 +533,15 @@ check_data_region (struct tar_sparse_file *file, size_t i)
if (bytes_read == SAFE_READ_ERROR)
{
read_diag_details (file->stat_info->orig_file_name,
- file->stat_info->sparse_map[i].offset
- + file->stat_info->sparse_map[i].numbytes
- - size_left,
+ (file->stat_info->sparse_map[i].offset
+ + file->stat_info->sparse_map[i].numbytes
+ - size_left),
rdsize);
return false;
}
file->dumped_size += bytes_read;
size_left -= bytes_read;
+ mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
if (memcmp (blk->buffer, diff_buffer, rdsize))
{
report_difference (file->stat_info, _("Contents differ"));
@@ -531,25 +559,27 @@ sparse_diff_file (int fd, struct tar_stat_info *st)
size_t i;
off_t offset = 0;
+ if (!tar_sparse_init (&file))
+ return dump_status_not_implemented;
+
file.stat_info = st;
file.fd = fd;
-
- if (!sparse_select_optab (&file)
- || !tar_sparse_init (&file))
- return dump_status_not_implemented;
+ file.seekable = true; /* File *must* be seekable for compare to work */
rc = tar_sparse_decode_header (&file);
+ mv_begin_read (st);
for (i = 0; rc && i < file.stat_info->sparse_map_avail; i++)
{
rc = check_sparse_region (&file,
offset, file.stat_info->sparse_map[i].offset)
- && check_data_region (&file, i);
+ && check_data_region (&file, i);
offset = file.stat_info->sparse_map[i].offset
+ file.stat_info->sparse_map[i].numbytes;
}
if (!rc)
skip_file (file.stat_info->archive_file_size - file.dumped_size);
+ mv_end ();
tar_sparse_done (&file);
return rc;
@@ -559,18 +589,18 @@ sparse_diff_file (int fd, struct tar_stat_info *st)
/* Old GNU Format. The sparse file information is stored in the
oldgnu_header in the following manner:
- The header is marked with type 'S'. Its `size' field contains
+ The header is marked with type 'S'. Its 'size' field contains
the cumulative size of all non-empty blocks of the file. The
- actual file size is stored in `realsize' member of oldgnu_header.
+ actual file size is stored in 'realsize' member of oldgnu_header.
- The map of the file is stored in a list of `struct sparse'.
+ The map of the file is stored in a list of 'struct sparse'.
Each struct contains offset to the block of data and its
size (both as octal numbers). The first file header contains
at most 4 such structs (SPARSES_IN_OLDGNU_HEADER). If the map
- contains more structs, then the field `isextended' of the main
- header is set to 1 (binary) and the `struct sparse_header'
+ contains more structs, then the field 'isextended' of the main
+ header is set to 1 (binary) and the 'struct sparse_header'
header follows, containing at most 21 following structs
- (SPARSES_IN_SPARSE_HEADER). If more structs follow, `isextended'
+ (SPARSES_IN_SPARSE_HEADER). If more structs follow, 'isextended'
field of the extended header is set and next next extension header
follows, etc... */
@@ -596,13 +626,14 @@ oldgnu_add_sparse (struct tar_sparse_file *file, struct sparse *s)
if (s->numbytes[0] == '\0')
return add_finish;
sp.offset = OFF_FROM_HEADER (s->offset);
- sp.numbytes = SIZE_FROM_HEADER (s->numbytes);
- if (sp.offset < 0
+ sp.numbytes = OFF_FROM_HEADER (s->numbytes);
+ if (sp.offset < 0 || sp.numbytes < 0
+ || INT_ADD_OVERFLOW (sp.offset, sp.numbytes)
|| file->stat_info->stat.st_size < sp.offset + sp.numbytes
|| file->stat_info->archive_file_size < 0)
return add_fail;
- sparse_add_map (file, &sp);
+ sparse_add_map (file->stat_info, &sp);
return add_ok;
}
@@ -611,10 +642,10 @@ oldgnu_fixup_header (struct tar_sparse_file *file)
{
/* NOTE! st_size was initialized from the header
which actually contains archived size. The following fixes it */
+ off_t realsize = OFF_FROM_HEADER (current_header->oldgnu_header.realsize);
file->stat_info->archive_file_size = file->stat_info->stat.st_size;
- file->stat_info->stat.st_size =
- OFF_FROM_HEADER (current_header->oldgnu_header.realsize);
- return true;
+ file->stat_info->stat.st_size = max (0, realsize);
+ return 0 <= realsize;
}
/* Convert old GNU format sparse data to internal representation */
@@ -624,7 +655,7 @@ oldgnu_get_sparse_info (struct tar_sparse_file *file)
size_t i;
union block *h = current_header;
int ext_p;
- static enum oldgnu_add_status rc;
+ enum oldgnu_add_status rc;
file->stat_info->sparse_map_avail = 0;
for (i = 0; i < SPARSES_IN_OLDGNU_HEADER; i++)
@@ -666,8 +697,8 @@ oldgnu_store_sparse_info (struct tar_sparse_file *file, size_t *pindex,
{
OFF_TO_CHARS (file->stat_info->sparse_map[*pindex].offset,
sp->offset);
- SIZE_TO_CHARS (file->stat_info->sparse_map[*pindex].numbytes,
- sp->numbytes);
+ OFF_TO_CHARS (file->stat_info->sparse_map[*pindex].numbytes,
+ sp->numbytes);
}
}
@@ -702,16 +733,14 @@ oldgnu_dump_header (struct tar_sparse_file *file)
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;
}
-static struct tar_sparse_optab oldgnu_optab = {
+static struct tar_sparse_optab const oldgnu_optab = {
NULL, /* No init function */
NULL, /* No done function */
oldgnu_sparse_member_p,
@@ -737,10 +766,10 @@ star_fixup_header (struct tar_sparse_file *file)
{
/* NOTE! st_size was initialized from the header
which actually contains archived size. The following fixes it */
+ off_t realsize = OFF_FROM_HEADER (current_header->star_in_header.realsize);
file->stat_info->archive_file_size = file->stat_info->stat.st_size;
- file->stat_info->stat.st_size =
- OFF_FROM_HEADER (current_header->star_in_header.realsize);
- return true;
+ file->stat_info->stat.st_size = max (0, realsize);
+ return 0 <= realsize;
}
/* Convert STAR format sparse data to internal representation */
@@ -750,7 +779,7 @@ star_get_sparse_info (struct tar_sparse_file *file)
size_t i;
union block *h = current_header;
int ext_p;
- static enum oldgnu_add_status rc;
+ enum oldgnu_add_status rc = add_ok;
file->stat_info->sparse_map_avail = 0;
@@ -780,6 +809,7 @@ star_get_sparse_info (struct tar_sparse_file *file)
set_next_block_after (h);
for (i = 0; i < SPARSES_IN_STAR_EXT_HEADER && rc == add_ok; i++)
rc = oldgnu_add_sparse (file, &h->star_ext_header.sp[i]);
+ file->dumped_size += BLOCKSIZE;
}
if (rc == add_fail)
@@ -792,7 +822,7 @@ star_get_sparse_info (struct tar_sparse_file *file)
}
-static struct tar_sparse_optab star_optab = {
+static struct tar_sparse_optab const star_optab = {
NULL, /* No init function */
NULL, /* No done function */
star_sparse_member_p,
@@ -805,8 +835,12 @@ static struct tar_sparse_optab star_optab = {
};
-/* 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
@@ -814,46 +848,343 @@ static struct tar_sparse_optab star_optab = {
GNU.sparse.offset Offset of the next data block
GNU.sparse.numbytes Size of the next data block
end repeat
+
+ 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, whereas
+ POSIX requires the latest occurrence of the variable to override all
+ previous occurrences.
+
+ 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
+
+ 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->archive_file_size != file->stat_info->stat.st_size;
+ return file->stat_info->sparse_map_avail > 0
+ || file->stat_info->sparse_major > 0;
+}
+
+/* Start a header that uses the effective (shrunken) file size. */
+static union block *
+pax_start_header (struct tar_stat_info *st)
+{
+ off_t realsize = st->stat.st_size;
+ union block *blk;
+ st->stat.st_size = st->archive_file_size;
+ blk = start_header (st);
+ st->stat.st_size = realsize;
+ return blk;
}
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;
size_t i;
+ char nbuf[UINTMAX_STRSIZE_BOUND];
+ struct sp_array *map = file->stat_info->sparse_map;
+ char *save_file_name = NULL;
/* Store the real file size */
xheader_store ("GNU.sparse.size", file->stat_info, NULL);
xheader_store ("GNU.sparse.numblocks", file->stat_info, NULL);
- for (i = 0; i < file->stat_info->sparse_map_avail; i++)
+
+ if (xheader_keyword_deleted_p ("GNU.sparse.map")
+ || tar_sparse_minor == 0)
{
- xheader_store ("GNU.sparse.offset", file->stat_info, &i);
- xheader_store ("GNU.sparse.numbytes", file->stat_info, &i);
+ for (i = 0; i < file->stat_info->sparse_map_avail; i++)
+ {
+ xheader_store ("GNU.sparse.offset", file->stat_info, &i);
+ xheader_store ("GNU.sparse.numbytes", file->stat_info, &i);
+ }
}
+ else
+ {
+ xheader_store ("GNU.sparse.name", file->stat_info, NULL);
+ save_file_name = file->stat_info->file_name;
+ 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);
+ xheader_string_begin (&file->stat_info->xhdr);
+ for (i = 0; i < file->stat_info->sparse_map_avail; i++)
+ {
+ if (i)
+ xheader_string_add (&file->stat_info->xhdr, ",");
+ xheader_string_add (&file->stat_info->xhdr,
+ umaxtostr (map[i].offset, nbuf));
+ xheader_string_add (&file->stat_info->xhdr, ",");
+ xheader_string_add (&file->stat_info->xhdr,
+ umaxtostr (map[i].numbytes, nbuf));
+ }
+ if (!xheader_string_end (&file->stat_info->xhdr,
+ "GNU.sparse.map"))
+ {
+ free (file->stat_info->file_name);
+ file->stat_info->file_name = save_file_name;
+ return false;
+ }
+ }
+ blk = pax_start_header (file->stat_info);
+ finish_header (file->stat_info, blk, block_ordinal);
+ if (save_file_name)
+ {
+ free (file->stat_info->file_name);
+ file->stat_info->file_name = save_file_name;
+ }
+ 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 const *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;
+ file->dumped_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);
+ /* Make sure the created header name is shorter than NAME_FIELD_SIZE: */
+ if (strlen (file->stat_info->file_name) > NAME_FIELD_SIZE)
+ file->stat_info->file_name[NAME_FIELD_SIZE] = 0;
+
+ blk = pax_start_header (file->stat_info);
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;
+
+ return (file->stat_info->sparse_major == 0) ?
+ pax_dump_header_0 (file) : 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;
+
+ errno = 0;
+ 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); \
+ file->dumped_size += BLOCKSIZE; \
+ 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);
+ file->dumped_size += BLOCKSIZE;
+ 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 (off_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 pax_optab = {
+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,
};
-