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Diffstat (limited to 'src/buffer.c')
| -rw-r--r-- | src/buffer.c | 2048 |
1 files changed, 2048 insertions, 0 deletions
diff --git a/src/buffer.c b/src/buffer.c new file mode 100644 index 0000000..dcbfd02 --- /dev/null +++ b/src/buffer.c @@ -0,0 +1,2048 @@ +/* Buffer management for tar. + + Copyright 1988, 1992-1994, 1996-1997, 1999-2010, 2013-2014, 2016 Free + Software Foundation, Inc. + + This file is part of GNU tar. + + GNU tar 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 3 of the License, or + (at your option) any later version. + + GNU tar is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + + Written by John Gilmore, on 1985-08-25. */ + +#include <system.h> +#include <system-ioctl.h> + +#include <signal.h> + +#include <closeout.h> +#include <fnmatch.h> +#include <human.h> +#include <quotearg.h> + +#include "common.h" +#include <rmt.h> + +/* Number of retries before giving up on read. */ +#define READ_ERROR_MAX 10 + +/* Variables. */ + +static tarlong prev_written; /* bytes written on previous volumes */ +static tarlong bytes_written; /* bytes written on this volume */ +static void *record_buffer[2]; /* allocated memory */ +static union block *record_buffer_aligned[2]; +static int record_index; + +/* FIXME: The following variables should ideally be static to this + module. However, this cannot be done yet. The cleanup continues! */ + +union block *record_start; /* start of record of archive */ +union block *record_end; /* last+1 block of archive record */ +union block *current_block; /* current block of archive */ +enum access_mode access_mode; /* how do we handle the archive */ +off_t records_read; /* number of records read from this archive */ +off_t records_written; /* likewise, for records written */ +extern off_t records_skipped; /* number of records skipped at the start + of the archive, defined in delete.c */ + +static off_t record_start_block; /* block ordinal at record_start */ + +/* Where we write list messages (not errors, not interactions) to. */ +FILE *stdlis; + +static void backspace_output (void); + +/* PID of child program, if compress_option or remote archive access. */ +static pid_t child_pid; + +/* Error recovery stuff */ +static int read_error_count; + +/* Have we hit EOF yet? */ +static bool hit_eof; + +static bool read_full_records = false; + +/* We're reading, but we just read the last block and it's time to update. + Declared in update.c + + FIXME: Either eliminate it or move it to common.h. +*/ +extern bool time_to_start_writing; + +bool write_archive_to_stdout; + +static void (*flush_write_ptr) (size_t); +static void (*flush_read_ptr) (void); + + +char *volume_label; +char *continued_file_name; +uintmax_t continued_file_size; +uintmax_t continued_file_offset; + + +static int volno = 1; /* which volume of a multi-volume tape we're + on */ +static int global_volno = 1; /* volume number to print in external + messages */ + +bool write_archive_to_stdout; + + +/* Multi-volume tracking support */ + +/* When creating a multi-volume archive, each 'bufmap' represents + a member stored (perhaps partly) in the current record buffer. + After flushing the record to the output media, all bufmaps that + represent fully written members are removed from the list, then + the sizeleft and start numbers in the remaining bufmaps are updated. + + When reading from a multi-volume archive, the list degrades to a + single element, which keeps information about the member currently + being read. +*/ + +struct bufmap +{ + struct bufmap *next; /* Pointer to the next map entry */ + size_t start; /* Offset of the first data block */ + char *file_name; /* Name of the stored file */ + off_t sizetotal; /* Size of the stored file */ + off_t sizeleft; /* Size left to read/write */ +}; +static struct bufmap *bufmap_head, *bufmap_tail; + +/* This variable, when set, inhibits updating the bufmap chain after + a write. This is necessary when writing extended POSIX headers. */ +static int inhibit_map; + +void +mv_begin_write (const char *file_name, off_t totsize, off_t sizeleft) +{ + if (multi_volume_option) + { + struct bufmap *bp = xmalloc (sizeof bp[0]); + if (bufmap_tail) + bufmap_tail->next = bp; + else + bufmap_head = bp; + bufmap_tail = bp; + + bp->next = NULL; + bp->start = current_block - record_start; + bp->file_name = xstrdup (file_name); + bp->sizetotal = totsize; + bp->sizeleft = sizeleft; + } +} + +static struct bufmap * +bufmap_locate (size_t off) +{ + struct bufmap *map; + + for (map = bufmap_head; map; map = map->next) + { + if (!map->next + || off < map->next->start * BLOCKSIZE) + break; + } + return map; +} + +static void +bufmap_free (struct bufmap *mark) +{ + struct bufmap *map; + for (map = bufmap_head; map && map != mark; ) + { + struct bufmap *next = map->next; + free (map->file_name); + free (map); + map = next; + } + bufmap_head = map; + if (!bufmap_head) + bufmap_tail = bufmap_head; +} + +static void +bufmap_reset (struct bufmap *map, ssize_t fixup) +{ + bufmap_free (map); + if (map) + { + for (; map; map = map->next) + map->start += fixup; + } +} + + +static struct tar_stat_info dummy; + +void +buffer_write_global_xheader (void) +{ + xheader_write_global (&dummy.xhdr); +} + +void +mv_begin_read (struct tar_stat_info *st) +{ + mv_begin_write (st->orig_file_name, st->stat.st_size, st->stat.st_size); +} + +void +mv_end (void) +{ + if (multi_volume_option) + bufmap_free (NULL); +} + +void +mv_size_left (off_t size) +{ + if (bufmap_head) + bufmap_head->sizeleft = size; +} + + +/* Functions. */ + +void +clear_read_error_count (void) +{ + read_error_count = 0; +} + + +/* Time-related functions */ + +static double duration; + +void +set_start_time (void) +{ + gettime (&start_time); + volume_start_time = start_time; + last_stat_time = start_time; +} + +static void +set_volume_start_time (void) +{ + gettime (&volume_start_time); + last_stat_time = volume_start_time; +} + +double +compute_duration (void) +{ + struct timespec now; + gettime (&now); + duration += ((now.tv_sec - last_stat_time.tv_sec) + + (now.tv_nsec - last_stat_time.tv_nsec) / 1e9); + gettime (&last_stat_time); + return duration; +} + + +/* Compression detection */ + +enum compress_type { + ct_none, /* Unknown compression type */ + ct_tar, /* Plain tar file */ + ct_compress, + ct_gzip, + ct_bzip2, + ct_lzip, + ct_lzma, + ct_lzop, + ct_xz +}; + +static enum compress_type archive_compression_type = ct_none; + +struct zip_magic +{ + enum compress_type type; + size_t length; + char const *magic; +}; + +struct zip_program +{ + enum compress_type type; + char const *program; + char const *option; +}; + +static struct zip_magic const magic[] = { + { ct_none, 0, 0 }, + { ct_tar, 0, 0 }, + { ct_compress, 2, "\037\235" }, + { ct_gzip, 2, "\037\213" }, + { ct_bzip2, 3, "BZh" }, + { ct_lzip, 4, "LZIP" }, + { ct_lzma, 6, "\xFFLZMA" }, + { ct_lzop, 4, "\211LZO" }, + { ct_xz, 6, "\xFD" "7zXZ" }, +}; + +#define NMAGIC (sizeof(magic)/sizeof(magic[0])) + +static struct zip_program zip_program[] = { + { ct_compress, COMPRESS_PROGRAM, "-Z" }, + { ct_compress, GZIP_PROGRAM, "-z" }, + { ct_gzip, GZIP_PROGRAM, "-z" }, + { ct_bzip2, BZIP2_PROGRAM, "-j" }, + { ct_bzip2, "lbzip2", "-j" }, + { ct_lzip, LZIP_PROGRAM, "--lzip" }, + { ct_lzma, LZMA_PROGRAM, "--lzma" }, + { ct_lzma, XZ_PROGRAM, "-J" }, + { ct_lzop, LZOP_PROGRAM, "--lzop" }, + { ct_xz, XZ_PROGRAM, "-J" }, + { ct_none } +}; + +static struct zip_program const * +find_zip_program (enum compress_type type, int *pstate) +{ + int i; + + for (i = *pstate; zip_program[i].type != ct_none; i++) + { + if (zip_program[i].type == type) + { + *pstate = i + 1; + return zip_program + i; + } + } + *pstate = i; + return NULL; +} + +const char * +first_decompress_program (int *pstate) +{ + struct zip_program const *zp; + + if (use_compress_program_option) + return use_compress_program_option; + + if (archive_compression_type == ct_none) + return NULL; + + *pstate = 0; + zp = find_zip_program (archive_compression_type, pstate); + return zp ? zp->program : NULL; +} + +const char * +next_decompress_program (int *pstate) +{ + struct zip_program const *zp; + + if (use_compress_program_option) + return NULL; + zp = find_zip_program (archive_compression_type, pstate); + return zp ? zp->program : NULL; +} + +static const char * +compress_option (enum compress_type type) +{ + struct zip_program const *zp; + int i = 0; + zp = find_zip_program (type, &i); + return zp ? zp->option : NULL; +} + +/* Check if the file ARCHIVE is a compressed archive. */ +static enum compress_type +check_compressed_archive (bool *pshort) +{ + struct zip_magic const *p; + bool sfr; + bool temp; + + if (!pshort) + pshort = &temp; + + /* Prepare global data needed for find_next_block: */ + record_end = record_start; /* set up for 1st record = # 0 */ + sfr = read_full_records; + read_full_records = true; /* Suppress fatal error on reading a partial + record */ + *pshort = find_next_block () == 0; + + /* Restore global values */ + read_full_records = sfr; + + if ((strcmp (record_start->header.magic, TMAGIC) == 0 || + strcmp (record_start->buffer + offsetof (struct posix_header, magic), + OLDGNU_MAGIC) == 0) && + tar_checksum (record_start, true) == HEADER_SUCCESS) + /* Probably a valid header */ + return ct_tar; + + for (p = magic + 2; p < magic + NMAGIC; p++) + if (memcmp (record_start->buffer, p->magic, p->length) == 0) + return p->type; + + return ct_none; +} + +/* Guess if the archive is seekable. */ +static void +guess_seekable_archive (void) +{ + struct stat st; + + if (subcommand_option == DELETE_SUBCOMMAND) + { + /* The current code in delete.c is based on the assumption that + skip_member() reads all data from the archive. So, we should + make sure it won't use seeks. On the other hand, the same code + depends on the ability to backspace a record in the archive, + so setting seekable_archive to false is technically incorrect. + However, it is tested only in skip_member(), so it's not a + problem. */ + seekable_archive = false; + } + + if (seek_option != -1) + { + seekable_archive = !!seek_option; + return; + } + + if (!multi_volume_option && !use_compress_program_option + && fstat (archive, &st) == 0) + seekable_archive = S_ISREG (st.st_mode); + else + seekable_archive = false; +} + +/* Open an archive named archive_name_array[0]. Detect if it is + a compressed archive of known type and use corresponding decompression + program if so */ +static int +open_compressed_archive (void) +{ + archive = rmtopen (archive_name_array[0], O_RDONLY | O_BINARY, + MODE_RW, rsh_command_option); + if (archive == -1) + return archive; + + if (!multi_volume_option) + { + if (!use_compress_program_option) + { + bool shortfile; + enum compress_type type = check_compressed_archive (&shortfile); + + switch (type) + { + case ct_tar: + if (shortfile) + ERROR ((0, 0, _("This does not look like a tar archive"))); + return archive; + + case ct_none: + if (shortfile) + ERROR ((0, 0, _("This does not look like a tar archive"))); + set_compression_program_by_suffix (archive_name_array[0], NULL); + if (!use_compress_program_option) + return archive; + break; + + default: + archive_compression_type = type; + break; + } + } + + /* FD is not needed any more */ + rmtclose (archive); + + hit_eof = false; /* It might have been set by find_next_block in + check_compressed_archive */ + + /* Open compressed archive */ + child_pid = sys_child_open_for_uncompress (); + read_full_records = true; + } + + records_read = 0; + record_end = record_start; /* set up for 1st record = # 0 */ + + return archive; +} + +static int +print_stats (FILE *fp, const char *text, tarlong numbytes) +{ + char abbr[LONGEST_HUMAN_READABLE + 1]; + char rate[LONGEST_HUMAN_READABLE + 1]; + int n = 0; + + int human_opts = human_autoscale | human_base_1024 | human_SI | human_B; + + if (text && text[0]) + n += fprintf (fp, "%s: ", gettext (text)); + return n + fprintf (fp, TARLONG_FORMAT " (%s, %s/s)", + numbytes, + human_readable (numbytes, abbr, human_opts, 1, 1), + (0 < duration && numbytes / duration < (uintmax_t) -1 + ? human_readable (numbytes / duration, rate, human_opts, 1, 1) + : "?")); +} + +/* Format totals to file FP. FORMATS is an array of strings to output + before each data item (bytes read, written, deleted, in that order). + EOR is a delimiter to output after each item (used only if deleting + from the archive), EOL is a delimiter to add at the end of the output + line. */ +int +format_total_stats (FILE *fp, char const *const *formats, int eor, int eol) +{ + int n; + + switch (subcommand_option) + { + case CREATE_SUBCOMMAND: + case CAT_SUBCOMMAND: + case UPDATE_SUBCOMMAND: + case APPEND_SUBCOMMAND: + n = print_stats (fp, formats[TF_WRITE], + prev_written + bytes_written); + break; + + case DELETE_SUBCOMMAND: + { + char buf[UINTMAX_STRSIZE_BOUND]; + n = print_stats (fp, formats[TF_READ], + records_read * record_size); + + fputc (eor, fp); + n++; + + n += print_stats (fp, formats[TF_WRITE], + prev_written + bytes_written); + + fputc (eor, fp); + n++; + + if (formats[TF_DELETED] && formats[TF_DELETED][0]) + n += fprintf (fp, "%s: ", gettext (formats[TF_DELETED])); + n += fprintf (fp, "%s", + STRINGIFY_BIGINT ((records_read - records_skipped) + * record_size + - (prev_written + bytes_written), buf)); + } + break; + + case EXTRACT_SUBCOMMAND: + case LIST_SUBCOMMAND: + case DIFF_SUBCOMMAND: + n = print_stats (fp, _(formats[TF_READ]), + records_read * record_size); + break; + + default: + abort (); + } + if (eol) + { + fputc (eol, fp); + n++; + } + return n; +} + +static char const *const default_total_format[] = { + N_("Total bytes read"), + /* Amanda 2.4.1p1 looks for "Total bytes written: [0-9][0-9]*". */ + N_("Total bytes written"), + N_("Total bytes deleted") +}; + +void +print_total_stats (void) +{ + format_total_stats (stderr, default_total_format, '\n', '\n'); +} + +/* Compute and return the block ordinal at current_block. */ +off_t +current_block_ordinal (void) +{ + return record_start_block + (current_block - record_start); +} + +/* If the EOF flag is set, reset it, as well as current_block, etc. */ +void +reset_eof (void) +{ + if (hit_eof) + { + hit_eof = false; + current_block = record_start; + record_end = record_start + blocking_factor; + access_mode = ACCESS_WRITE; + } +} + +/* Return the location of the next available input or output block. + Return zero for EOF. Once we have returned zero, we just keep returning + it, to avoid accidentally going on to the next file on the tape. */ +union block * +find_next_block (void) +{ + if (current_block == record_end) + { + if (hit_eof) + return 0; + flush_archive (); + if (current_block == record_end) + { + hit_eof = true; + return 0; + } + } + return current_block; +} + +/* Indicate that we have used all blocks up thru BLOCK. */ +void +set_next_block_after (union block *block) +{ + while (block >= current_block) + current_block++; + + /* Do *not* flush the archive here. If we do, the same argument to + set_next_block_after could mean the next block (if the input record + is exactly one block long), which is not what is intended. */ + + if (current_block > record_end) + abort (); +} + +/* Return the number of bytes comprising the space between POINTER + through the end of the current buffer of blocks. This space is + available for filling with data, or taking data from. POINTER is + usually (but not always) the result of previous find_next_block call. */ +size_t +available_space_after (union block *pointer) +{ + return record_end->buffer - pointer->buffer; +} + +/* Close file having descriptor FD, and abort if close unsuccessful. */ +void +xclose (int fd) +{ + if (close (fd) != 0) + close_error (_("(pipe)")); +} + +static void +init_buffer (void) +{ + if (! record_buffer_aligned[record_index]) + record_buffer_aligned[record_index] = + page_aligned_alloc (&record_buffer[record_index], record_size); + + record_start = record_buffer_aligned[record_index]; + current_block = record_start; + record_end = record_start + blocking_factor; +} + +static void +check_tty (enum access_mode mode) +{ + /* Refuse to read archive from and write it to a tty. */ + if (strcmp (archive_name_array[0], "-") == 0 + && isatty (mode == ACCESS_READ ? STDIN_FILENO : STDOUT_FILENO)) + { + FATAL_ERROR ((0, 0, + mode == ACCESS_READ + ? _("Refusing to read archive contents from terminal " + "(missing -f option?)") + : _("Refusing to write archive contents to terminal " + "(missing -f option?)"))); + } +} + +/* Open an archive file. The argument specifies whether we are + reading or writing, or both. */ +static void +_open_archive (enum access_mode wanted_access) +{ + int backed_up_flag = 0; + + if (record_size == 0) + FATAL_ERROR ((0, 0, _("Invalid value for record_size"))); + + if (archive_names == 0) + FATAL_ERROR ((0, 0, _("No archive name given"))); + + tar_stat_destroy (¤t_stat_info); + + record_index = 0; + init_buffer (); + + /* When updating the archive, we start with reading. */ + access_mode = wanted_access == ACCESS_UPDATE ? ACCESS_READ : wanted_access; + check_tty (access_mode); + + read_full_records = read_full_records_option; + + records_read = 0; + + if (use_compress_program_option) + { + switch (wanted_access) + { + case ACCESS_READ: + child_pid = sys_child_open_for_uncompress (); + read_full_records = true; + record_end = record_start; /* set up for 1st record = # 0 */ + break; + + case ACCESS_WRITE: + child_pid = sys_child_open_for_compress (); + break; + + case ACCESS_UPDATE: + abort (); /* Should not happen */ + break; + } + + if (!index_file_name + && wanted_access == ACCESS_WRITE + && strcmp (archive_name_array[0], "-") == 0) + stdlis = stderr; + } + else if (strcmp (archive_name_array[0], "-") == 0) + { + read_full_records = true; /* could be a pipe, be safe */ + if (verify_option) + FATAL_ERROR ((0, 0, _("Cannot verify stdin/stdout archive"))); + + switch (wanted_access) + { + case ACCESS_READ: + { + bool shortfile; + enum compress_type type; + + archive = STDIN_FILENO; + type = check_compressed_archive (&shortfile); + if (type != ct_tar && type != ct_none) + FATAL_ERROR ((0, 0, + _("Archive is compressed. Use %s option"), + compress_option (type))); + if (shortfile) + ERROR ((0, 0, _("This does not look like a tar archive"))); + } + break; + + case ACCESS_WRITE: + archive = STDOUT_FILENO; + if (!index_file_name) + stdlis = stderr; + break; + + case ACCESS_UPDATE: + archive = STDIN_FILENO; + write_archive_to_stdout = true; + record_end = record_start; /* set up for 1st record = # 0 */ + if (!index_file_name) + stdlis = stderr; + break; + } + } + else + switch (wanted_access) + { + case ACCESS_READ: + archive = open_compressed_archive (); + if (archive >= 0) + guess_seekable_archive (); + break; + + case ACCESS_WRITE: + if (backup_option) + { + maybe_backup_file (archive_name_array[0], 1); + backed_up_flag = 1; + } + if (verify_option) + archive = rmtopen (archive_name_array[0], O_RDWR | O_CREAT | O_BINARY, + MODE_RW, rsh_command_option); + else + archive = rmtcreat (archive_name_array[0], MODE_RW, + rsh_command_option); + break; + + case ACCESS_UPDATE: + archive = rmtopen (archive_name_array[0], + O_RDWR | O_CREAT | O_BINARY, + MODE_RW, rsh_command_option); + + switch (check_compressed_archive (NULL)) + { + case ct_none: + case ct_tar: + break; + + default: + FATAL_ERROR ((0, 0, + _("Cannot update compressed archives"))); + } + break; + } + + if (archive < 0 + || (! _isrmt (archive) && !sys_get_archive_stat ())) + { + int saved_errno = errno; + + if (backed_up_flag) + undo_last_backup (); + errno = saved_errno; + open_fatal (archive_name_array[0]); + } + + sys_detect_dev_null_output (); + sys_save_archive_dev_ino (); + SET_BINARY_MODE (archive); + + switch (wanted_access) + { + case ACCESS_READ: + find_next_block (); /* read it in, check for EOF */ + break; + + case ACCESS_UPDATE: + case ACCESS_WRITE: + records_written = 0; + break; + } +} + +/* Perform a write to flush the buffer. */ +static ssize_t +_flush_write (void) +{ + ssize_t status; + + checkpoint_run (true); + if (tape_length_option && tape_length_option <= bytes_written) + { + errno = ENOSPC; + status = 0; + } + else if (dev_null_output) + status = record_size; + else + status = sys_write_archive_buffer (); + + if (status && multi_volume_option && !inhibit_map) + { + struct bufmap *map = bufmap_locate (status); + if (map) + { + size_t delta = status - map->start * BLOCKSIZE; + if (delta > map->sizeleft) + delta = map->sizeleft; + map->sizeleft -= delta; + if (map->sizeleft == 0) + map = map->next; + bufmap_reset (map, map ? (- map->start) : 0); + } + } + return status; +} + +/* Handle write errors on the archive. Write errors are always fatal. + Hitting the end of a volume does not cause a write error unless the + write was the first record of the volume. */ +void +archive_write_error (ssize_t status) +{ + /* It might be useful to know how much was written before the error + occurred. */ + if (totals_option) + { + int e = errno; + print_total_stats (); + errno = e; + } + + write_fatal_details (*archive_name_cursor, status, record_size); +} + +/* Handle read errors on the archive. If the read should be retried, + return to the caller. */ +void +archive_read_error (void) +{ + read_error (*archive_name_cursor); + + if (record_start_block == 0) + FATAL_ERROR ((0, 0, _("At beginning of tape, quitting now"))); + + /* Read error in mid archive. We retry up to READ_ERROR_MAX times and + then give up on reading the archive. */ + + if (read_error_count++ > READ_ERROR_MAX) + FATAL_ERROR ((0, 0, _("Too many errors, quitting"))); + return; +} + +static bool +archive_is_dev (void) +{ + struct stat st; + + if (fstat (archive, &st)) + { + stat_diag (*archive_name_cursor); + return false; + } + return S_ISBLK (st.st_mode) || S_ISCHR (st.st_mode); +} + +static void +short_read (size_t status) +{ + size_t left; /* bytes left */ + char *more; /* pointer to next byte to read */ + + more = record_start->buffer + status; + left = record_size - status; + + if (left && left % BLOCKSIZE == 0 + && (warning_option & WARN_RECORD_SIZE) + && record_start_block == 0 && status != 0 + && archive_is_dev ()) + { + unsigned long rsize = status / BLOCKSIZE; + WARN ((0, 0, + ngettext ("Record size = %lu block", + "Record size = %lu blocks", + rsize), + rsize)); + } + + while (left % BLOCKSIZE != 0 + || (left && status && read_full_records)) + { + if (status) + while ((status = rmtread (archive, more, left)) == SAFE_READ_ERROR) + archive_read_error (); + + if (status == 0) + break; + + if (! read_full_records) + { + unsigned long rest = record_size - left; + + FATAL_ERROR ((0, 0, + ngettext ("Unaligned block (%lu byte) in archive", + "Unaligned block (%lu bytes) in archive", + rest), + rest)); + } + + left -= status; + more += status; + } + + record_end = record_start + (record_size - left) / BLOCKSIZE; + records_read++; +} + +/* Flush the current buffer to/from the archive. */ +void +flush_archive (void) +{ + size_t buffer_level; + + if (access_mode == ACCESS_READ && time_to_start_writing) + { + access_mode = ACCESS_WRITE; + time_to_start_writing = false; + backspace_output (); + if (record_end - record_start < blocking_factor) + { + memset (record_end, 0, + (blocking_factor - (record_end - record_start)) + * BLOCKSIZE); + record_end = record_start + blocking_factor; + return; + } + } + + buffer_level = current_block->buffer - record_start->buffer; + record_start_block += record_end - record_start; + current_block = record_start; + record_end = record_start + blocking_factor; + + switch (access_mode) + { + case ACCESS_READ: + flush_read (); + break; + + case ACCESS_WRITE: + flush_write_ptr (buffer_level); + break; + + case ACCESS_UPDATE: + abort (); + } +} + +/* Backspace the archive descriptor by one record worth. If it's a + tape, MTIOCTOP will work. If it's something else, try to seek on + it. If we can't seek, we lose! */ +static void +backspace_output (void) +{ +#ifdef MTIOCTOP + { + struct mtop operation; + + operation.mt_op = MTBSR; + operation.mt_count = 1; + if (rmtioctl (archive, MTIOCTOP, (char *) &operation) >= 0) + return; + if (errno == EIO && rmtioctl (archive, MTIOCTOP, (char *) &operation) >= 0) + return; + } +#endif + + { + off_t position = rmtlseek (archive, (off_t) 0, SEEK_CUR); + + /* Seek back to the beginning of this record and start writing there. */ + + position -= record_end->buffer - record_start->buffer; + if (position < 0) + position = 0; + if (rmtlseek (archive, position, SEEK_SET) != position) + { + /* Lseek failed. Try a different method. */ + + WARN ((0, 0, + _("Cannot backspace archive file; it may be unreadable without -i"))); + + /* Replace the first part of the record with NULs. */ + + if (record_start->buffer != output_start) + memset (record_start->buffer, 0, + output_start - record_start->buffer); + } + } +} + +off_t +seek_archive (off_t size) +{ + off_t start = current_block_ordinal (); + off_t offset; + off_t nrec, nblk; + off_t skipped = (blocking_factor - (current_block - record_start)) + * BLOCKSIZE; + + if (size <= skipped) + return 0; + + /* Compute number of records to skip */ + nrec = (size - skipped) / record_size; + if (nrec == 0) + return 0; + offset = rmtlseek (archive, nrec * record_size, SEEK_CUR); + if (offset < 0) + return offset; + + if (offset % record_size) + FATAL_ERROR ((0, 0, _("rmtlseek not stopped at a record boundary"))); + + /* Convert to number of records */ + offset /= BLOCKSIZE; + /* Compute number of skipped blocks */ + nblk = offset - start; + + /* Update buffering info */ + records_read += nblk / blocking_factor; + record_start_block = offset - blocking_factor; + current_block = record_end; + + return nblk; +} + +/* Close the archive file. */ +void +close_archive (void) +{ + if (time_to_start_writing || access_mode == ACCESS_WRITE) + { + flush_archive (); + if (current_block > record_start) + flush_archive (); + } + + compute_duration (); + if (verify_option) + verify_volume (); + + if (rmtclose (archive) != 0) + close_error (*archive_name_cursor); + + sys_wait_for_child (child_pid, hit_eof); + + tar_stat_destroy (¤t_stat_info); + free (record_buffer[0]); + free (record_buffer[1]); + bufmap_free (NULL); +} + +void +write_fatal_details (char const *name, ssize_t status, size_t size) +{ + write_error_details (name, status, size); + if (rmtclose (archive) != 0) + close_error (*archive_name_cursor); + sys_wait_for_child (child_pid, false); + fatal_exit (); +} + +/* Called to initialize the global volume number. */ +void +init_volume_number (void) +{ + FILE *file = fopen (volno_file_option, "r"); + + if (file) + { + if (fscanf (file, "%d", &global_volno) != 1 + || global_volno < 0) + FATAL_ERROR ((0, 0, _("%s: contains invalid volume number"), + quotearg_colon (volno_file_option))); + if (ferror (file)) + read_error (volno_file_option); + if (fclose (file) != 0) + close_error (volno_file_option); + } + else if (errno != ENOENT) + open_error (volno_file_option); +} + +/* Called to write out the closing global volume number. */ +void +closeout_volume_number (void) +{ + FILE *file = fopen (volno_file_option, "w"); + + if (file) + { + fprintf (file, "%d\n", global_volno); + if (ferror (file)) + write_error (volno_file_option); + if (fclose (file) != 0) + close_error (volno_file_option); + } + else + open_error (volno_file_option); +} + + +static void +increase_volume_number (void) +{ + global_volno++; + if (global_volno < 0) + FATAL_ERROR ((0, 0, _("Volume number overflow"))); + volno++; +} + +static void +change_tape_menu (FILE *read_file) +{ + char *input_buffer = NULL; + size_t size = 0; + bool stop = false; + + while (!stop) + { + fputc ('\007', stderr); + fprintf (stderr, + _("Prepare volume #%d for %s and hit return: "), + global_volno + 1, quote (*archive_name_cursor)); + fflush (stderr); + + if (getline (&input_buffer, &size, read_file) <= 0) + { + WARN ((0, 0, _("EOF where user reply was expected"))); + + if (subcommand_option != EXTRACT_SUBCOMMAND + && subcommand_option != LIST_SUBCOMMAND + && subcommand_option != DIFF_SUBCOMMAND) + WARN ((0, 0, _("WARNING: Archive is incomplete"))); + + fatal_exit (); + } + + if (input_buffer[0] == '\n' + || input_buffer[0] == 'y' + || input_buffer[0] == 'Y') + break; + + switch (input_buffer[0]) + { + case '?': + { + fprintf (stderr, _("\ + n name Give a new file name for the next (and subsequent) volume(s)\n\ + q Abort tar\n\ + y or newline Continue operation\n")); + if (!restrict_option) + fprintf (stderr, _(" ! Spawn a subshell\n")); + fprintf (stderr, _(" ? Print this list\n")); + } + break; + + case 'q': + /* Quit. */ + + WARN ((0, 0, _("No new volume; exiting.\n"))); + + if (subcommand_option != EXTRACT_SUBCOMMAND + && subcommand_option != LIST_SUBCOMMAND + && subcommand_option != DIFF_SUBCOMMAND) + WARN ((0, 0, _("WARNING: Archive is incomplete"))); + + fatal_exit (); + + case 'n': + /* Get new file name. */ + + { + char *name; + char *cursor; + + for (name = input_buffer + 1; + *name == ' ' || *name == '\t'; + name++) + ; + + for (cursor = name; *cursor && *cursor != '\n'; cursor++) + ; + *cursor = '\0'; + + if (name[0]) + { + /* FIXME: the following allocation is never reclaimed. */ + *archive_name_cursor = xstrdup (name); + stop = true; + } + else + fprintf (stderr, "%s", + _("File name not specified. Try again.\n")); + } + break; + + case '!': + if (!restrict_option) + { + sys_spawn_shell (); + break; + } + /* FALL THROUGH */ + + default: + fprintf (stderr, _("Invalid input. Type ? for help.\n")); + } + } + free (input_buffer); +} + +/* We've hit the end of the old volume. Close it and open the next one. + Return nonzero on success. +*/ +static bool +new_volume (enum access_mode mode) +{ + static FILE *read_file; + static int looped; + int prompt; + + if (!read_file && !info_script_option) + /* FIXME: if fopen is used, it will never be closed. */ + read_file = archive == STDIN_FILENO ? fopen (TTY_NAME, "r") : stdin; + + if (now_verifying) + return false; + if (verify_option) + verify_volume (); + + assign_string (&volume_label, NULL); + assign_string (&continued_file_name, NULL); + continued_file_size = continued_file_offset = 0; + current_block = record_start; + + if (rmtclose (archive) != 0) + close_error (*archive_name_cursor); + + archive_name_cursor++; + if (archive_name_cursor == archive_name_array + archive_names) + { + archive_name_cursor = archive_name_array; + looped = 1; + } + prompt = looped; + + tryagain: + if (prompt) + { + /* We have to prompt from now on. */ + + if (info_script_option) + { + if (volno_file_option) + closeout_volume_number (); + if (sys_exec_info_script (archive_name_cursor, global_volno+1)) + FATAL_ERROR ((0, 0, _("%s command failed"), + quote (info_script_option))); + } + else + change_tape_menu (read_file); + } + + if (strcmp (archive_name_cursor[0], "-") == 0) + { + read_full_records = true; + archive = STDIN_FILENO; + } + else if (verify_option) + archive = rmtopen (*archive_name_cursor, O_RDWR | O_CREAT, MODE_RW, + rsh_command_option); + else + switch (mode) + { + case ACCESS_READ: + archive = rmtopen (*archive_name_cursor, O_RDONLY, MODE_RW, + rsh_command_option); + guess_seekable_archive (); + break; + + case ACCESS_WRITE: + if (backup_option) + maybe_backup_file (*archive_name_cursor, 1); + archive = rmtcreat (*archive_name_cursor, MODE_RW, + rsh_command_option); + break; + + case ACCESS_UPDATE: + archive = rmtopen (*archive_name_cursor, O_RDWR | O_CREAT, MODE_RW, + rsh_command_option); + break; + } + + if (archive < 0) + { + open_warn (*archive_name_cursor); + if (!verify_option && mode == ACCESS_WRITE && backup_option) + undo_last_backup (); + prompt = 1; + goto tryagain; + } + + SET_BINARY_MODE (archive); + + return true; +} + +static bool +read_header0 (struct tar_stat_info *info) +{ + enum read_header rc; + + tar_stat_init (info); + rc = read_header (¤t_header, info, read_header_auto); + if (rc == HEADER_SUCCESS) + { + set_next_block_after (current_header); + return true; + } + ERROR ((0, 0, _("This does not look like a tar archive"))); + return false; +} + +static bool +try_new_volume (void) +{ + size_t status; + union block *header; + enum access_mode acc; + + switch (subcommand_option) + { + case APPEND_SUBCOMMAND: + case CAT_SUBCOMMAND: + case UPDATE_SUBCOMMAND: + acc = ACCESS_UPDATE; + break; + + default: + acc = ACCESS_READ; + break; + } + + if (!new_volume (acc)) + return true; + + while ((status = rmtread (archive, record_start->buffer, record_size)) + == SAFE_READ_ERROR) + archive_read_error (); + + if (status != record_size) + short_read (status); + + header = find_next_block (); + if (!header) + { + WARN ((0, 0, _("This does not look like a tar archive"))); + return false; + } + + switch (header->header.typeflag) + { + case XGLTYPE: + { + tar_stat_init (&dummy); + if (read_header (&header, &dummy, read_header_x_global) + != HEADER_SUCCESS_EXTENDED) + { + WARN ((0, 0, _("This does not look like a tar archive"))); + return false; + } + + xheader_decode (&dummy); /* decodes values from the global header */ + tar_stat_destroy (&dummy); + + /* The initial global header must be immediately followed by + an extended PAX header for the first member in this volume. + However, in some cases tar may split volumes in the middle + of a PAX header. This is incorrect, and should be fixed + in the future versions. In the meantime we must be + prepared to correctly list and extract such archives. + + If this happens, the following call to read_header returns + HEADER_FAILURE, which is ignored. + + See also tests/multiv07.at */ + + switch (read_header (&header, &dummy, read_header_auto)) + { + case HEADER_SUCCESS: + set_next_block_after (header); + break; + + case HEADER_FAILURE: + break; + + default: + WARN ((0, 0, _("This does not look like a tar archive"))); + return false; + } + break; + } + + case GNUTYPE_VOLHDR: + if (!read_header0 (&dummy)) + return false; + tar_stat_destroy (&dummy); + assign_string (&volume_label, current_header->header.name); + set_next_block_after (header); + header = find_next_block (); + if (header->header.typeflag != GNUTYPE_MULTIVOL) + break; + /* FALL THROUGH */ + + case GNUTYPE_MULTIVOL: + if (!read_header0 (&dummy)) + return false; + tar_stat_destroy (&dummy); + assign_string (&continued_file_name, current_header->header.name); + continued_file_size = + UINTMAX_FROM_HEADER (current_header->header.size); + continued_file_offset = + UINTMAX_FROM_HEADER (current_header->oldgnu_header.offset); + break; + + default: + break; + } + + if (bufmap_head) + { + uintmax_t s; + if (!continued_file_name) + { + WARN ((0, 0, _("%s is not continued on this volume"), + quote (bufmap_head->file_name))); + return false; + } + + if (strcmp (continued_file_name, bufmap_head->file_name)) + { + if ((archive_format == GNU_FORMAT || archive_format == OLDGNU_FORMAT) + && strlen (bufmap_head->file_name) >= NAME_FIELD_SIZE + && strncmp (continued_file_name, bufmap_head->file_name, + NAME_FIELD_SIZE) == 0) + WARN ((0, 0, + _("%s is possibly continued on this volume: header contains truncated name"), + quote (bufmap_head->file_name))); + else + { + WARN ((0, 0, _("%s is not continued on this volume"), + quote (bufmap_head->file_name))); + return false; + } + } + + s = continued_file_size + continued_file_offset; + + if (bufmap_head->sizetotal != s || s < continued_file_offset) + { + char totsizebuf[UINTMAX_STRSIZE_BOUND]; + char s1buf[UINTMAX_STRSIZE_BOUND]; + char s2buf[UINTMAX_STRSIZE_BOUND]; + + WARN ((0, 0, _("%s is the wrong size (%s != %s + %s)"), + quote (continued_file_name), + STRINGIFY_BIGINT (bufmap_head->sizetotal, totsizebuf), + STRINGIFY_BIGINT (continued_file_size, s1buf), + STRINGIFY_BIGINT (continued_file_offset, s2buf))); + return false; + } + + if (bufmap_head->sizetotal - bufmap_head->sizeleft != + continued_file_offset) + { + char totsizebuf[UINTMAX_STRSIZE_BOUND]; + char s1buf[UINTMAX_STRSIZE_BOUND]; + char s2buf[UINTMAX_STRSIZE_BOUND]; + + WARN ((0, 0, _("This volume is out of sequence (%s - %s != %s)"), + STRINGIFY_BIGINT (bufmap_head->sizetotal, totsizebuf), + STRINGIFY_BIGINT (bufmap_head->sizeleft, s1buf), + STRINGIFY_BIGINT (continued_file_offset, s2buf))); + + return false; + } + } + + increase_volume_number (); + return true; +} + + +#define VOLUME_TEXT " Volume " +#define VOLUME_TEXT_LEN (sizeof VOLUME_TEXT - 1) + +char * +drop_volume_label_suffix (const char *label) +{ + const char *p; + size_t len = strlen (label); + + if (len < 1) + return NULL; + + for (p = label + len - 1; p > label && isdigit ((unsigned char) *p); p--) + ; + if (p > label && p - (VOLUME_TEXT_LEN - 1) > label) + { + p -= VOLUME_TEXT_LEN - 1; + if (memcmp (p, VOLUME_TEXT, VOLUME_TEXT_LEN) == 0) + { + char *s = xmalloc ((len = p - label) + 1); + memcpy (s, label, len); + s[len] = 0; + return s; + } + } + + return NULL; +} + +/* Check LABEL against the volume label, seen as a globbing + pattern. Return true if the pattern matches. In case of failure, + retry matching a volume sequence number before giving up in + multi-volume mode. */ +static bool +check_label_pattern (const char *label) +{ + char *string; + bool result = false; + + if (fnmatch (volume_label_option, label, 0) == 0) + return true; + + if (!multi_volume_option) + return false; + + string = drop_volume_label_suffix (label); + if (string) + { + result = fnmatch (string, volume_label_option, 0) == 0; + free (string); + } + return result; +} + +/* Check if the next block contains a volume label and if this matches + the one given in the command line */ +static void +match_volume_label (void) +{ + if (!volume_label) + { + union block *label = find_next_block (); + + if (!label) + FATAL_ERROR ((0, 0, _("Archive not labeled to match %s"), + quote (volume_label_option))); + if (label->header.typeflag == GNUTYPE_VOLHDR) + { + if (memchr (label->header.name, '\0', sizeof label->header.name)) + assign_string (&volume_label, label->header.name); + else + { + volume_label = xmalloc (sizeof (label->header.name) + 1); + memcpy (volume_label, label->header.name, + sizeof (label->header.name)); + volume_label[sizeof (label->header.name)] = 0; + } + } + else if (label->header.typeflag == XGLTYPE) + { + struct tar_stat_info st; + tar_stat_init (&st); + xheader_read (&st.xhdr, label, + OFF_FROM_HEADER (label->header.size)); + xheader_decode (&st); + tar_stat_destroy (&st); + } + } + + if (!volume_label) + FATAL_ERROR ((0, 0, _("Archive not labeled to match %s"), + quote (volume_label_option))); + + if (!check_label_pattern (volume_label)) + FATAL_ERROR ((0, 0, _("Volume %s does not match %s"), + quote_n (0, volume_label), + quote_n (1, volume_label_option))); +} + +/* Mark the archive with volume label STR. */ +static void +_write_volume_label (const char *str) +{ + if (archive_format == POSIX_FORMAT) + xheader_store ("GNU.volume.label", &dummy, str); + else + { + union block *label = find_next_block (); + + memset (label, 0, BLOCKSIZE); + + strcpy (label->header.name, str); + assign_string (¤t_stat_info.file_name, + label->header.name); + current_stat_info.had_trailing_slash = + strip_trailing_slashes (current_stat_info.file_name); + + label->header.typeflag = GNUTYPE_VOLHDR; + TIME_TO_CHARS (start_time.tv_sec, label->header.mtime); + finish_header (¤t_stat_info, label, -1); + set_next_block_after (label); + } +} + +#define VOL_SUFFIX "Volume" + +/* Add a volume label to a part of multi-volume archive */ +static void +add_volume_label (void) +{ + char buf[UINTMAX_STRSIZE_BOUND]; + char *p = STRINGIFY_BIGINT (volno, buf); + char *s = xmalloc (strlen (volume_label_option) + sizeof VOL_SUFFIX + + strlen (p) + 2); + sprintf (s, "%s %s %s", volume_label_option, VOL_SUFFIX, p); + _write_volume_label (s); + free (s); +} + +static void +add_chunk_header (struct bufmap *map) +{ + if (archive_format == POSIX_FORMAT) + { + off_t block_ordinal; + union block *blk; + struct tar_stat_info st; + + memset (&st, 0, sizeof st); + st.orig_file_name = st.file_name = map->file_name; + st.stat.st_mode = S_IFREG|S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH; + st.stat.st_uid = getuid (); + st.stat.st_gid = getgid (); + st.orig_file_name = xheader_format_name (&st, + "%d/GNUFileParts.%p/%f.%n", + volno); + st.file_name = st.orig_file_name; + st.archive_file_size = st.stat.st_size = map->sizeleft; + + block_ordinal = current_block_ordinal (); + blk = start_header (&st); + if (!blk) + abort (); /* FIXME */ + finish_header (&st, blk, block_ordinal); + free (st.orig_file_name); + } +} + + +/* Add a volume label to the current archive */ +static void +write_volume_label (void) +{ + if (multi_volume_option) + add_volume_label (); + else + _write_volume_label (volume_label_option); +} + +/* Write GNU multi-volume header */ +static void +gnu_add_multi_volume_header (struct bufmap *map) +{ + int tmp; + union block *block = find_next_block (); + + if (strlen (map->file_name) > NAME_FIELD_SIZE) + WARN ((0, 0, + _("%s: file name too long to be stored in a GNU multivolume header, truncated"), + quotearg_colon (map->file_name))); + + memset (block, 0, BLOCKSIZE); + + strncpy (block->header.name, map->file_name, NAME_FIELD_SIZE); + block->header.typeflag = GNUTYPE_MULTIVOL; + + OFF_TO_CHARS (map->sizeleft, block->header.size); + OFF_TO_CHARS (map->sizetotal - map->sizeleft, + block->oldgnu_header.offset); + + tmp = verbose_option; + verbose_option = 0; + finish_header (¤t_stat_info, block, -1); + verbose_option = tmp; + set_next_block_after (block); +} + +/* Add a multi volume header to the current archive. The exact header format + depends on the archive format. */ +static void +add_multi_volume_header (struct bufmap *map) +{ + if (archive_format == POSIX_FORMAT) + { + off_t d = map->sizetotal - map->sizeleft; + xheader_store ("GNU.volume.filename", &dummy, map->file_name); + xheader_store ("GNU.volume.size", &dummy, &map->sizeleft); + xheader_store ("GNU.volume.offset", &dummy, &d); + } + else + gnu_add_multi_volume_header (map); +} + + +/* Low-level flush functions */ + +/* Simple flush read (no multi-volume or label extensions) */ +static void +simple_flush_read (void) +{ + size_t status; /* result from system call */ + + checkpoint_run (false); + + /* Clear the count of errors. This only applies to a single call to + flush_read. */ + + read_error_count = 0; /* clear error count */ + + if (write_archive_to_stdout && record_start_block != 0) + { + archive = STDOUT_FILENO; + status = sys_write_archive_buffer (); + archive = STDIN_FILENO; + if (status != record_size) + archive_write_error (status); + } + + for (;;) + { + status = rmtread (archive, record_start->buffer, record_size); + if (status == record_size) + { + records_read++; + return; + } + if (status == SAFE_READ_ERROR) + { + archive_read_error (); + continue; /* try again */ + } + break; + } + short_read (status); +} + +/* Simple flush write (no multi-volume or label extensions) */ +static void +simple_flush_write (size_t level __attribute__((unused))) +{ + ssize_t status; + + status = _flush_write (); + if (status != record_size) + archive_write_error (status); + else + { + records_written++; + bytes_written += status; + } +} + + +/* GNU flush functions. These support multi-volume and archive labels in + GNU and PAX archive formats. */ + +static void +_gnu_flush_read (void) +{ + size_t status; /* result from system call */ + + checkpoint_run (false); + + /* Clear the count of errors. This only applies to a single call to + flush_read. */ + + read_error_count = 0; /* clear error count */ + + if (write_archive_to_stdout && record_start_block != 0) + { + archive = STDOUT_FILENO; + status = sys_write_archive_buffer (); + archive = STDIN_FILENO; + if (status != record_size) + archive_write_error (status); + } + + for (;;) + { + status = rmtread (archive, record_start->buffer, record_size); + if (status == record_size) + { + records_read++; + return; + } + + /* The condition below used to include + || (status > 0 && !read_full_records) + This is incorrect since even if new_volume() succeeds, the + subsequent call to rmtread will overwrite the chunk of data + already read in the buffer, so the processing will fail */ + if ((status == 0 + || (status == SAFE_READ_ERROR && errno == ENOSPC)) + && multi_volume_option) + { + while (!try_new_volume ()) + ; + if (current_block == record_end) + /* Necessary for blocking_factor == 1 */ + flush_archive(); + return; + } + else if (status == SAFE_READ_ERROR) + { + archive_read_error (); + continue; + } + break; + } + short_read (status); +} + +static void +gnu_flush_read (void) +{ + flush_read_ptr = simple_flush_read; /* Avoid recursion */ + _gnu_flush_read (); + flush_read_ptr = gnu_flush_read; +} + +static void +_gnu_flush_write (size_t buffer_level) +{ + ssize_t status; + union block *header; + char *copy_ptr; + size_t copy_size; + size_t bufsize; + struct bufmap *map; + + status = _flush_write (); + if (status != record_size && !multi_volume_option) + archive_write_error (status); + else + { + if (status) + records_written++; + bytes_written += status; + } + + if (status == record_size) + { + return; + } + + map = bufmap_locate (status); + + if (status % BLOCKSIZE) + { + ERROR ((0, 0, _("write did not end on a block boundary"))); + archive_write_error (status); + } + + /* In multi-volume mode. */ + /* ENXIO is for the UNIX PC. */ + if (status < 0 && errno != ENOSPC && errno != EIO && errno != ENXIO) + archive_write_error (status); + + if (!new_volume (ACCESS_WRITE)) + return; + + tar_stat_destroy (&dummy); + + increase_volume_number (); + prev_written += bytes_written; + bytes_written = 0; + + copy_ptr = record_start->buffer + status; + copy_size = buffer_level - status; + + /* Switch to the next buffer */ + record_index = !record_index; + init_buffer (); + + inhibit_map = 1; + + if (volume_label_option) + add_volume_label (); + + if (map) + add_multi_volume_header (map); + + write_extended (true, &dummy, find_next_block ()); + tar_stat_destroy (&dummy); + + if (map) + add_chunk_header (map); + header = find_next_block (); + bufmap_reset (map, header - record_start); + bufsize = available_space_after (header); + inhibit_map = 0; + while (bufsize < copy_size) + { + memcpy (header->buffer, copy_ptr, bufsize); + copy_ptr += bufsize; + copy_size -= bufsize; + set_next_block_after (header + (bufsize - 1) / BLOCKSIZE); + header = find_next_block (); + bufsize = available_space_after (header); + } + memcpy (header->buffer, copy_ptr, copy_size); + memset (header->buffer + copy_size, 0, bufsize - copy_size); + set_next_block_after (header + (copy_size - 1) / BLOCKSIZE); + find_next_block (); +} + +static void +gnu_flush_write (size_t buffer_level) +{ + flush_write_ptr = simple_flush_write; /* Avoid recursion */ + _gnu_flush_write (buffer_level); + flush_write_ptr = gnu_flush_write; +} + +void +flush_read (void) +{ + flush_read_ptr (); +} + +void +flush_write (void) +{ + flush_write_ptr (record_size); +} + +void +open_archive (enum access_mode wanted_access) +{ + flush_read_ptr = gnu_flush_read; + flush_write_ptr = gnu_flush_write; + + _open_archive (wanted_access); + switch (wanted_access) + { + case ACCESS_READ: + case ACCESS_UPDATE: + if (volume_label_option) + match_volume_label (); + break; + + case ACCESS_WRITE: + records_written = 0; + if (volume_label_option) + write_volume_label (); + break; + } + set_volume_start_time (); +} |