#ifndef lint
static const char rcsid[] =
- "$Id: tape.c,v 1.25 2001/02/22 10:57:40 stelian Exp $";
+ "$Id: tape.c,v 1.26 2001/03/18 15:35:44 stelian Exp $";
#endif /* not lint */
#include <config.h>
static long fssize = MAXBSIZE;
static int mt = -1;
static int pipein = 0;
+static int magtapein = 0; /* input is from magtape */
static char magtape[MAXPATHLEN];
static char magtapeprefix[MAXPATHLEN];
static int blkcnt;
static int numtrec;
-static char *tapebuf;
+static char *tapebuf; /* input buffer for read */
+static int bufsize; /* buffer size without prefix */
static char *tbufptr = NULL; /* active tape buffer */
#ifdef HAVE_ZLIB
static char *comprbuf; /* uncompress work buf */
-static size_t comprlen;
+static size_t comprlen; /* size including prefix */
#endif
static union u_spcl endoftapemark;
static long blksread; /* blocks read since last header */
static void xtrmapskip __P((char *, size_t));
static void xtrskip __P((char *, size_t));
+#ifdef HAVE_ZLIB
+static void newcomprbuf __P((long));
+static void readtape_set __P((char *));
+static void readtape_uncompr __P((char *));
+static void readtape_comprfile __P((char *));
+static void readtape_comprtape __P((char *));
+static char *decompress_tapebuf __P((struct tapebuf *, int));
+static void msg_read_error __P((char *));
+#endif
+static int read_a_block __P((int, void *, size_t, long *));
+#define PREFIXSIZE sizeof(struct tapebuf)
+
#define COMPARE_ONTHEFLY 1
#if COMPARE_ONTHEFLY
static int readmapflag;
/*
- * Set up an input source
+ * Set up an input source. This is called from main.c before setup() is.
*/
void
setinput(char *source)
static int tapebufsize = -1;
ntrec = size;
+ bufsize = ntrec * TP_BSIZE;
if (size <= tapebufsize)
return;
if (tapebuf != NULL)
free(tapebuf);
- tapebuf = malloc(size * TP_BSIZE);
+ tapebuf = malloc(size * TP_BSIZE + sizeof(struct tapebuf));
if (tapebuf == NULL)
errx(1, "Cannot allocate space for tape buffer");
tapebufsize = size;
+}
+
#ifdef HAVE_ZLIB
+static void
+newcomprbuf(long size)
+{
+ if (size <= comprlen)
+ return;
+ comprlen = size + sizeof(struct tapebuf);
if (comprbuf != NULL)
free(comprbuf);
- comprlen = size * TP_BSIZE;
comprbuf = malloc(comprlen);
if (comprbuf == NULL)
- errx(1, "Cannot allocate space for uncompress buffer");
-#endif /* HAVE_ZLIB */
+ errx(1, "Cannot allocate space for decompress buffer");
}
+#endif /* HAVE_ZLIB */
/*
* Verify that the tape drive can be accessed and
{
int i, j, *ip;
struct stat stbuf;
+ struct mtget mt_stat;
Vprintf(stdout, "Verify tape and initialize maps\n");
#ifdef RRESTORE
if (mt < 0)
err(1, "%s", magtape);
volno = 1;
+ if (!pipein) {
+ /* need to know if input is really from a tape */
+#ifdef RRESTORE
+ if (host)
+ magtapein = rmtioctl(MTNOP, 1) != -1;
+ else
+#endif
+ magtapein = ioctl(mt, MTIOCGET, (char *) &mt_stat) == 0;
+ }
+
+ Vprintf(stdout,"Input is from %s\n", magtapein? "tape": "file/pipe");
setdumpnum();
FLUSHTAPEBUF();
- if (!pipein && !bflag)
- findtapeblksize();
+ findtapeblksize();
if (gethead(&spcl) == FAIL) {
blkcnt--; /* push back this block */
blksread--;
fprintf(stderr, "Converting to new file system format.\n");
}
- if (spcl.c_flags & DR_COMPRESSED) {
+ if (zflag) {
fprintf(stderr, "Dump tape is compressed.\n");
#ifdef HAVE_ZLIB
- zflag = 1;
+ newcomprbuf(bufsize);
#else
errx(1,"This restore version doesn't support decompression");
#endif /* HAVE_ZLIB */
/* NOTREACHED */
}
+#ifdef HAVE_ZLIB
+static void (*readtape_func)(char *) = readtape_set;
+
/*
* Read TP_BSIZE blocks from the input.
* Handle read errors, and end of media.
+ * Decompress compressed blocks.
*/
static void
readtape(char *buf)
{
- ssize_t rd, newvol, i;
- int cnt, seek_failed;
+ (*readtape_func)(buf); /* call the actual processing routine */
+}
+
+/*
+ * Set function pointer for readtape() routine. zflag and magtapein must
+ * be correctly set before the first call to readtape().
+ */
+static void
+readtape_set(char *buf)
+{
+ if (!zflag)
+ readtape_func = readtape_uncompr;
+ else {
+ if (magtapein)
+ readtape_func = readtape_comprtape;
+ else
+ readtape_func = readtape_comprfile;
+ }
+ readtape(buf);
+}
+
+#endif /* HAVE_ZLIB */
+
+/*
+ * This is the original readtape(), it's used for reading uncompressed input.
+ * Read TP_BSIZE blocks from the input.
+ * Handle read errors, and end of media.
+ */
+static void
#ifdef HAVE_ZLIB
- int cresult;
- struct tapebuf* tpb;
- unsigned long worklen;
+readtape_uncompr(char *buf)
+#else
+readtape(char *buf)
#endif
+{
+ ssize_t rd, newvol, i;
+ int cnt, seek_failed;
if (blkcnt < numtrec) {
memmove(buf, &tbufptr[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
if (numtrec == 0)
numtrec = ntrec;
cnt = ntrec * TP_BSIZE;
+ if (zflag)
+ cnt += PREFIXSIZE;
rd = 0;
getmore:
#ifdef RRESTORE
#endif
i = read(mt, &tapebuf[rd], cnt);
-#ifdef HAVE_ZLIB
- if (i < 0)
- goto readerror;
- if (i == 0 && !pipein)
- goto endoftape;
-
- if (zflag && i != ntrec * TP_BSIZE) {
- tpb = (struct tapebuf *) tapebuf;
- if (i != tpb->clen + sizeof(struct tapebuf))
- errx(1,"tape is not a compressed dump tape");
- worklen = comprlen;
- cresult = uncompress(comprbuf, &worklen, tpb->buf, tpb->clen);
- if (cresult != Z_OK)
- errx(1,"tape is not a compressed dump tape");
- if (worklen != tpb->unclen)
- errx(1,"decompression error, length mismatch");
- i = worklen;
- tbufptr = comprbuf;
- }
-#endif /* HAVE_ZLIB */
-
/*
* Check for mid-tape short read error.
* If found, skip rest of buffer and start with the next.
/*
* Handle read error.
*/
-#ifdef HAVE_ZLIB
-readerror:
-#endif
if (i < 0) {
fprintf(stderr, "Tape read error while ");
switch (curfile.action) {
/*
* Handle end of tape.
*/
-#ifdef HAVE_ZLIB
-endoftape:
-#endif
if (i == 0) {
Vprintf(stdout, "End-of-tape encountered\n");
if (!pipein) {
tpblksread++;
}
+#ifdef HAVE_ZLIB
+
+/*
+ * Read a compressed format block from a file or pipe and uncompress it.
+ * Attempt to handle read errors, and end of file.
+ */
static void
-findtapeblksize(void)
+readtape_comprfile(char *buf)
{
- register long i;
+ long rl, size, i, ret;
+ int newvol;
+ struct tapebuf *tpb;
+ if (blkcnt < numtrec) {
+ memmove(buf, &tbufptr[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
+ blksread++;
+ tpblksread++;
+ return;
+ }
+ /* need to read the next block */
+ tbufptr = tapebuf;
for (i = 0; i < ntrec; i++)
((struct s_spcl *)&tapebuf[i * TP_BSIZE])->c_magic = 0;
+ numtrec = ntrec;
+ tpb = (struct tapebuf *) tapebuf;
+
+ /* read the block prefix */
+ ret = read_a_block(mt, tapebuf, PREFIXSIZE, &rl);
+ if (ret <= 0)
+ goto readerr;
+
+ /* read the data */
+ size = tpb->length;
+ if (size > bufsize) {
+ /* something's wrong */
+ Vprintf(stdout, "Prefix size error, max size %d, got %ld\n",
+ bufsize, size);
+ size = bufsize;
+ tpb->length = bufsize;
+ }
+ ret = read_a_block(mt, tpb->buf, size, &rl);
+ if (ret <= 0)
+ goto readerr;
+
+ tbufptr = decompress_tapebuf(tpb, rl + PREFIXSIZE);
+ if (tbufptr == NULL) {
+ msg_read_error("File decompression error while");
+ if (!yflag && !reply("continue"))
+ exit(1);
+ memset(tapebuf, 0, bufsize);
+ tbufptr = tapebuf;
+ }
+
blkcnt = 0;
+ memmove(buf, &tbufptr[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
+ blksread++;
+ tpblksread++;
+ return;
+
+readerr:
+ /* Errors while reading from a file or pipe are catastrophic. Since
+ * there are no block boundaries, it's impossible to bypass the
+ * block in error and find the start of the next block.
+ */
+ if (ret == 0) {
+ /* It's possible to have multiple input files using -M
+ * and -f file1,file2...
+ */
+ Vprintf(stdout, "End-of-File encountered\n");
+ if (!pipein) {
+ newvol = volno + 1;
+ volno = 0;
+ numtrec = 0;
+ getvol(newvol);
+ readtape(buf);
+ return;
+ }
+ }
+ msg_read_error("Read error while");
+ /* if (!yflag && !reply("continue")) */
+ exit(1);
+}
+
+/*
+ * Read compressed data from a tape and uncompress it.
+ * Handle read errors, and end of media.
+ * Since a tape consists of separate physical blocks, we try
+ * to recover from errors by repositioning the tape to the next
+ * block.
+ */
+static void
+readtape_comprtape(char *buf)
+{
+ long rl, size, i;
+ int ret, newvol;
+ struct tapebuf *tpb;
+ struct mtop tcom;
+
+ if (blkcnt < numtrec) {
+ memmove(buf, &tbufptr[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
+ blksread++;
+ tpblksread++;
+ return;
+ }
+ /* need to read the next block */
+ tbufptr = tapebuf;
+ for (i = 0; i < ntrec; i++)
+ ((struct s_spcl *)&tapebuf[i * TP_BSIZE])->c_magic = 0;
+ numtrec = ntrec;
+ tpb = (struct tapebuf *) tapebuf;
+
+ /* read the block */
+ size = bufsize + PREFIXSIZE;
+ ret = read_a_block(mt, tapebuf, size, &rl);
+ if (ret <= 0)
+ goto readerr;
+
+ tbufptr = decompress_tapebuf(tpb, rl);
+ if (tbufptr == NULL) {
+ msg_read_error("Tape decompression error while");
+ if (!yflag && !reply("continue"))
+ exit(1);
+ memset(tapebuf, 0, PREFIXSIZE + bufsize);
+ tbufptr = tapebuf;
+ }
+ goto moverecord;
+
+readerr:
+ /* Handle errors: EOT switches to the next volume, other errors
+ * attempt to position the tape to the next block.
+ */
+ if (ret == 0) {
+ Vprintf(stdout, "End-of-tape encountered\n");
+ newvol = volno + 1;
+ volno = 0;
+ numtrec = 0;
+ getvol(newvol);
+ readtape(buf);
+ return;
+ }
+
+ msg_read_error("Tape read error while");
+ if (!yflag && !reply("continue"))
+ exit(1);
+ memset(tapebuf, 0, PREFIXSIZE + bufsize);
+ tbufptr = tapebuf;
+
#ifdef RRESTORE
if (host)
- i = rmtread(tapebuf, (size_t)(ntrec * TP_BSIZE));
+ rl = rmtioctl(MTFSR, 1);
else
#endif
- i = read(mt, tapebuf, (size_t)(ntrec * TP_BSIZE));
+ {
+ tcom.mt_op = MTFSR;
+ tcom.mt_count = 1;
+ rl = ioctl(mt, MTIOCTOP, &tcom);
+ }
+
+ if (rl < 0) {
+ warn("continuation failed");
+ if (!yflag && !reply("assume end-of-tape and continue"))
+ exit(1);
+ ret = 0; /* end of tape */
+ goto readerr;
+ }
+
+moverecord:
+ blkcnt = 0;
+ memmove(buf, &tbufptr[(blkcnt++ * TP_BSIZE)], TP_BSIZE);
+ blksread++;
+ tpblksread++;
+}
+
+/*
+ * Decompress a struct tapebuf into a buffer. readsize is the size read
+ * from the tape/file and is used for error messages. Returns a pointer
+ * to the location of the uncompressed buffer or NULL on errors.
+ * Adjust numtrec and complain for a short block.
+ */
+static char *
+decompress_tapebuf(struct tapebuf *tpbin, int readsize)
+{
+ /* If zflag is on, all blocks have a struct tapebuf prefix */
+ /* zflag gets set in setup() from the dump header */
+ int cresult, blocklen;
+ unsigned long worklen;
+ char *output = NULL,*reason = NULL, *lengtherr = NULL;
+
+ /* build a length error message */
+ blocklen = tpbin->length;
+ if (readsize < blocklen + PREFIXSIZE)
+ lengtherr = "short";
+ else
+ if (readsize > blocklen + PREFIXSIZE)
+ lengtherr = "long";
+
+ worklen = comprlen;
+ cresult = Z_OK;
+ if (tpbin->compressed) {
+ /* uncompress whatever we read, if it fails, complain later */
+ cresult = uncompress(comprbuf, &worklen, tpbin->buf, blocklen);
+ output = comprbuf;
+ }
+ else {
+ output = tpbin->buf;
+ worklen = blocklen;
+ }
+ switch (cresult) {
+ case Z_OK:
+ if (worklen != ntrec * TP_BSIZE) {
+ /* short block, shouldn't happen, but... */
+ reason = "length mismatch";
+ if (worklen % TP_BSIZE == 0)
+ numtrec = worklen / TP_BSIZE;
+ }
+ break;
+ case Z_MEM_ERROR:
+ reason = "not enough memory";
+ break;
+ case Z_BUF_ERROR:
+ reason = "buffer too small";
+ break;
+ case Z_DATA_ERROR:
+ reason = "data error";
+ break;
+ default:
+ reason = "unknown";
+ } /*switch */
+ if (reason) {
+ if (lengtherr)
+ fprintf(stderr, "%s compressed block: %d expected: %d\n",
+ lengtherr, readsize, tpbin->length + PREFIXSIZE);
+ fprintf(stderr, "decompression error, block %ld: %s\n",
+ tpblksread+1, reason);
+ if (cresult != Z_OK) output = NULL;
+ }
+ return output;
+}
+
+/*
+ * Print an error message for a read error.
+ * This was exteracted from the original readtape().
+ */
+static void
+msg_read_error(char *m)
+{
+ switch (curfile.action) {
+ default:
+ fprintf(stderr, "%s trying to set up tape\n", m);
+ break;
+ case UNKNOWN:
+ fprintf(stderr, "%s trying to resynchronize\n", m);
+ break;
+ case USING:
+ fprintf(stderr, "%s restoring %s\n", m, curfile.name);
+ break;
+ case SKIP:
+ fprintf(stderr, "%s skipping over inode %lu\n", m,
+ (unsigned long)curfile.ino);
+ break;
+ }
+}
+#endif /* HAVE_ZLIB */
+
+/*
+ * Read the first block and set the blocksize from its length. Test
+ * if the block looks like a compressed dump tape. setup() will make
+ * the final determination by checking the compressed flag if gethead()
+ * finds a valid header. The test here is necessary to offset the buffer
+ * by the size of the compressed prefix. zflag is set here so that
+ * readtape_set can set the correct function pointer for readtape().
+ * Note that the first block of each tape/file will not be compressed.
+ */
+static void
+findtapeblksize(void)
+{
+ long i;
+ size_t len;
+ struct tapebuf *tpb = (struct tapebuf *) tapebuf;
+ struct s_spcl *spclpt = (struct s_spcl *) tpb->buf;
- if (i <= 0)
- err(1, "tape read error");
- if (i % TP_BSIZE != 0)
- errx(1, "Tape block size (%ld) is not a multiple of dump block size (%d)",
- (long)i, TP_BSIZE);
+ for (i = 0; i < ntrec; i++)
+ ((struct s_spcl *)&tapebuf[i * TP_BSIZE])->c_magic = 0;
+ blkcnt = 0;
+ tbufptr = tapebuf;
+ /*
+ * For a pipe or file, read in the first record. For a tape, read
+ * the first block.
+ */
+ len = magtapein ? bufsize + PREFIXSIZE: TP_BSIZE;
+
+ if (read_a_block(mt, tapebuf, len, &i) <= 0)
+ errx(1, "Tape read error on first record");
+
+ /*
+ * If the input is from a file or a pipe, we read TP_BSIZE
+ * bytes looking for a compressed dump header, we then
+ * need to read in the rest of the record, as determined by
+ * tpb->length or bufsize. The first block of the dump is
+ * guaranteed to not be compressed so we look at the header.
+ */
+ if (!magtapein) {
+ if (tpb->length % TP_BSIZE == 0
+ && tpb->length <= bufsize
+ && tpb->compressed == 0
+ && spclpt->c_type == TS_TAPE
+ && spclpt->c_flags & DR_COMPRESSED) {
+ /* Looks like it's a compressed dump block prefix, */
+ /* read in the rest of the block based on tpb->length. */
+ len = tpb->length - TP_BSIZE + PREFIXSIZE;
+ if (read_a_block(mt, tapebuf+TP_BSIZE, len, &i) <= 0
+ || i != len)
+ errx(1,"Error reading dump file header");
+ tbufptr = tpb->buf;
+ numtrec = ntrec = tpb->length / TP_BSIZE;
+ zflag = 1;
+ }
+ else {
+ /* read in the rest of the block based on bufsize */
+ len = bufsize - TP_BSIZE;
+ if (read_a_block(mt, tapebuf+TP_BSIZE, len, &i) <= 0
+ || i != len)
+ errx(1,"Error reading dump file header");
+ tbufptr = tapebuf;
+ numtrec = ntrec;
+ }
+ Vprintf(stdout, "Input block size is %ld\n", ntrec);
+ return;
+ }
+
+ /*
+ * If the input is a tape, we tried to read PREFIXSIZE +
+ * ntrec * TP_BSIZE bytes. If it's not a compressed dump tape
+ * or the value of ntrec is too large, we have read less than
+ * what we asked for; adjust the value of ntrec and test for
+ * a compressed dump tape prefix.
+ */
+
+ if (i % TP_BSIZE != 0) {
+ if (i % TP_BSIZE == PREFIXSIZE
+ && tpb->compressed == 0
+ && spclpt->c_type == TS_TAPE
+ && spclpt->c_flags & DR_COMPRESSED) {
+
+ zflag = 1;
+ tbufptr = tpb->buf;
+ if (tpb->length > bufsize)
+ errx(1, "Tape blocksize is too large, use "
+ "\'-b %d\' ", tpb->length / TP_BSIZE);
+ }
+ else
+ errx(1, "Tape block size (%ld) is not a multiple of dump block size (%d)",
+ i, TP_BSIZE);
+ }
ntrec = i / TP_BSIZE;
numtrec = ntrec;
- tbufptr = tapebuf;
Vprintf(stdout, "Tape block size is %ld\n", ntrec);
}
+/*
+ * Read a block of data handling all of the messy details.
+ */
+static int read_a_block(int fd, void *buf, size_t len, long *lengthread)
+{
+ long i = 1, size;
+
+ size = len;
+ while (size > 0) {
+#ifdef RRESTORE
+ if (host)
+ i = rmtread(buf, size);
+ else
+#endif
+ i = read(fd, buf, size);
+
+ if (i <= 0)
+ break; /* EOD or error */
+ size -= i;
+ if (magtapein)
+ break; /* block at a time for mt */
+ buf += i;
+ }
+ *lengthread = len - size;
+ return i;
+}
+
void
closemt(void)
{
projects / dump.git / commitdiff