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revision 1.12
date: 2005/03/03 23:13:30; author: gray; state: Exp; lines: +1 -1
(sparse_scan_file): Bugfix. offset had incorrect type.
revision 1.11
date: 2005/02/02 11:01:49; author: gray; state: Exp; lines: +59 -14
Extract sparse files even if the output fd is not seekable.
Index: src/sparse.c
===================================================================
RCS file: /cvsroot/tar/tar/src/sparse.c,v
retrieving revision 1.10
retrieving revision 1.12
diff -u -p -r1.10 -r1.12
--- src/sparse.c 6 Sep 2004 14:28:56 -0000 1.10
+++ src/sparse.c 3 Mar 2005 23:13:30 -0000 1.12
@@ -46,6 +46,9 @@ struct tar_sparse_optab
struct tar_sparse_file
{
int fd; /* File descriptor */
+ bool seekable; /* Is fd seekable? */
+ size_t offset; /* Current offset in fd if seekable==false.
+ Otherwise unused */
size_t dumped_size; /* Number of bytes actually written
to the archive */
struct tar_stat_info *stat_info; /* Information about the file */
@@ -54,6 +57,39 @@ struct tar_sparse_file
reqiure */
};
+/* Dump zeros to file->fd until offset is reached. It is used instead of
+ lseek if the output file is not seekable */
+static long
+dump_zeros (struct tar_sparse_file *file, off_t offset)
+{
+ char buf[BLOCKSIZE];
+
+ if (offset - file->offset < 0)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset (buf, 0, sizeof buf);
+ while (file->offset < offset)
+ {
+ size_t size = offset - file->offset;
+ size_t wrbytes;
+
+ if (size > sizeof buf)
+ size = sizeof buf;
+ wrbytes = write (file->fd, buf, size);
+ if (wrbytes <= 0)
+ {
+ if (wrbytes == 0)
+ errno = EINVAL;
+ return -1;
+ }
+ file->offset += wrbytes;
+ }
+ return file->offset;
+}
+
static bool
tar_sparse_member_p (struct tar_sparse_file *file)
{
@@ -130,9 +166,16 @@ tar_sparse_fixup_header (struct tar_spar
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)
+ off_t off;
+
+ if (file->seekable)
+ off = lseek (file->fd, offset, SEEK_SET);
+ else
+ off = dump_zeros (file, offset);
+
+ if (off < 0)
{
seek_diag_details (file->stat_info->orig_file_name, offset);
return false;
@@ -182,10 +225,10 @@ sparse_scan_file (struct tar_sparse_file
{
static char buffer[BLOCKSIZE];
size_t count;
- size_t offset = 0;
+ off_t offset = 0;
struct sp_array sp = {0, 0};
- if (!lseek_or_error (file, 0, SEEK_SET))
+ if (!lseek_or_error (file, 0))
return false;
clear_block (buffer);
@@ -269,8 +312,7 @@ sparse_dump_region (struct tar_sparse_fi
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)
@@ -304,8 +346,7 @@ sparse_extract_region (struct tar_sparse
{
size_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 +354,7 @@ sparse_extract_region (struct tar_sparse
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)
@@ -330,6 +371,7 @@ sparse_extract_region (struct tar_sparse
count = full_write (file->fd, blk->buffer, wrbytes);
write_size -= count;
file->dumped_size += count;
+ file->offset += count;
if (count != wrbytes)
{
write_error_details (file->stat_info->orig_file_name,
@@ -351,7 +393,9 @@ sparse_dump_file (int fd, struct tar_sta
file.stat_info = st;
file.fd = fd;
-
+ file.seekable = true; /* File *must* be seekable for dump to work */
+ file.offset = 0;
+
if (!sparse_select_optab (&file)
|| !tar_sparse_init (&file))
return dump_status_not_implemented;
@@ -414,7 +458,9 @@ sparse_extract_file (int fd, struct tar_
file.stat_info = st;
file.fd = fd;
-
+ file.seekable = lseek (fd, 0, SEEK_SET) == 0;
+ file.offset = 0;
+
if (!sparse_select_optab (&file)
|| !tar_sparse_init (&file))
return dump_status_not_implemented;
@@ -450,7 +496,7 @@ 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)
@@ -486,8 +532,7 @@ check_data_region (struct tar_sparse_fil
{
size_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;
while (size_left > 0)
|
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