From 1b9c48d934b83a36f1192c5bfc2940870e19dd7c Mon Sep 17 00:00:00 2001 From: Sergey Poznyakoff Date: Mon, 7 Nov 2005 02:49:45 +0000 Subject: [PATCH] (sparse_diff_file): Bugfix: set seekable. (pax_dump_header): Store sparse map in GNU.sparse.map. If this variable has been explicitely deleted, use GNU.sparse.offset/ GNU.sparse.numbytes variables. --- src/sparse.c | 59 +++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 51 insertions(+), 8 deletions(-) diff --git a/src/sparse.c b/src/sparse.c index d16efc7..a39d0ed 100644 --- a/src/sparse.c +++ b/src/sparse.c @@ -54,7 +54,7 @@ struct tar_sparse_file 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 const *optab; + struct tar_sparse_optab const *optab; /* Operation table */ void *closure; /* Any additional data optab calls might require */ }; @@ -565,13 +565,14 @@ sparse_diff_file (int fd, struct tar_stat_info *st) file.stat_info = st; file.fd = fd; - + file.seekable = true; /* File *must* be seekable for compare to work */ + rc = tar_sparse_decode_header (&file); 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; } @@ -838,10 +839,28 @@ static struct tar_sparse_optab const star_optab = { 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 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. However, + 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. + + See FIXME-1.14-1.15.1-1.20, below. */ static bool @@ -856,16 +875,40 @@ pax_dump_header (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; + /* 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++) + + /* 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")) { - 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_string_begin (); + for (i = 0; i < file->stat_info->sparse_map_avail; i++) + { + if (i) + xheader_string_add (","); + xheader_string_add (umaxtostr (map[i].offset, nbuf)); + xheader_string_add (","); + xheader_string_add (umaxtostr (map[i].numbytes, nbuf)); + } + xheader_string_end ("GNU.sparse.map"); } - blk = start_header (file->stat_info); /* Store the effective (shrunken) file size */ OFF_TO_CHARS (file->stat_info->archive_file_size, blk->header.size); -- 2.44.0