X-Git-Url: https://git.wh0rd.org/?p=dump.git;a=blobdiff_plain;f=dump%2Ftape.c;h=edcf5d691925a6532dd71e8b30f75514d8190109;hp=54b387eac62559d092a687ab18eca75d7a36a479;hb=b8db960b14856a2ab86e044b2ffa53612d2aa489;hpb=88ac410d747e12ed2c1edd1ed0fdab994de71cf9 diff --git a/dump/tape.c b/dump/tape.c index 54b387e..edcf5d6 100644 --- a/dump/tape.c +++ b/dump/tape.c @@ -18,11 +18,7 @@ * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors + * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * @@ -41,7 +37,7 @@ #ifndef lint static const char rcsid[] = - "$Id: tape.c,v 1.68 2002/05/21 15:48:46 stelian Exp $"; + "$Id: tape.c,v 1.91 2009/06/18 09:50:54 stelian Exp $"; #endif /* not lint */ #include @@ -64,6 +60,11 @@ int write(), read(); #ifdef __linux__ #include #include +#include +#include /* for definition of BLKFLSBUF */ +#ifndef BLKFLSBUF /* last resort... */ +#define BLKFLSBUF _IO(0x12, 97) /* Flush buffer cache. */ +#endif #include #endif #include @@ -99,12 +100,17 @@ int write(), read(); #include #endif /* HAVE_BZLIB */ +#ifdef HAVE_LZO +#include +#endif /* HAVE_LZO */ + #include "dump.h" int writesize; /* size of malloc()ed buffer for tape */ long lastspclrec = -1; /* tape block number of last written header */ int trecno = 0; /* next record to write in current block */ -extern long blocksperfile; /* number of blocks per output file */ +extern long *blocksperfiles; /* number of blocks per output file(s) */ +long blocksperfiles_current; /* current position in blocksperfiles */ long blocksthisvol; /* number of blocks on current output file */ extern int ntrec; /* blocking factor on tape */ extern int cartridge; @@ -114,16 +120,21 @@ int eot_code = 1; long long tapea_bytes = 0; /* bytes_written at start of current volume */ static int magtapeout; /* output is really a tape */ -static ssize_t dump_atomic_read __P((int, void *, size_t)); -static ssize_t dump_atomic_write __P((int, const void *, size_t)); +static ssize_t dump_atomic_read __P((int, char *, size_t)); +static ssize_t dump_atomic_write __P((int, const char *, size_t)); +#ifdef WRITEDEBUG static void doslave __P((int, int, int)); +#else +static void doslave __P((int, int)); +#endif static void enslave __P((void)); static void flushtape __P((void)); static void killall __P((void)); static void rollforward __P((void)); #ifdef USE_QFA static int GetTapePos __P((long long *)); -static void MkTapeString __P((struct s_spcl *, long long)); +static int MkTapeString __P((struct s_spcl *, long long)); +#define FILESQFAPOS 20 #endif /* @@ -135,7 +146,7 @@ static void MkTapeString __P((struct s_spcl *, long long)); * The following structure defines the instruction packets sent to slaves. */ struct req { - daddr_t dblk; + ext2_loff_t dblk; int count; }; int reqsiz; @@ -176,6 +187,41 @@ static sigjmp_buf jmpbuf; /* where to jump to if we are ready when the */ static int gtperr = 0; #endif +/* + * Determine if we can use Linux' clone system call. If so, call it + * with the CLONE_IO flag so that all processes will share the same I/O + * context, allowing the I/O schedulers to make better scheduling decisions. + */ +#ifdef __linux__ +/* first, pull in the header files that define sys_clone and CLONE_IO */ +#include +#define _GNU_SOURCE +#include +#include +#undef _GNU_SOURCE + +/* If either is not present, fall back on the fork behaviour */ +#if ! defined(SYS_clone) || ! defined (CLONE_IO) +#define fork_clone_io fork +#else /* SYS_clone */ +/* CLONE_IO is available, determine which version of sys_clone to use */ +#include +/* + * Kernel 2.5.49 introduced two extra parameters to the clone system call. + * Neither is useful in our case, so this is easy to handle. + */ +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,49) +/* clone_flags, child_stack, parent_tidptr, child_tidptr */ +#define CLONE_ARGS SIGCHLD|CLONE_IO, 0, NULL, NULL +#else +#define CLONE_ARGS SIGCHLD|CLONE_IO, 0 +#endif /* LINUX_VERSION_CODE */ +pid_t fork_clone_io(void); +#endif /* SYS_clone */ +#else /* __linux__ not defined */ +#define fork_clone_io fork +#endif /* __linux__ */ + int alloctape(void) { @@ -191,7 +237,7 @@ alloctape(void) * repositioning after stopping, i.e, streaming mode, where the gap is * variable, 0.30" to 0.45". The gap is maximal when the tape stops. */ - if (blocksperfile == 0 && !unlimited) + if (!blocksperfiles && !unlimited) tenths = (cartridge ? 16 : density == 625 ? 5 : 8); else { tenths = 0; @@ -227,20 +273,20 @@ void writerec(const void *dp, int isspcl) { - slp->req[trecno].dblk = (daddr_t)0; + slp->req[trecno].dblk = (ext2_loff_t)0; slp->req[trecno].count = 1; /* XXX post increment triggers an egcs-1.1.2-12 bug on alpha/sparc */ *(union u_spcl *)(*(nextblock)) = *(union u_spcl *)dp; /* Need to write it to the archive file */ - if (Afile < 0 && isspcl && (spcl.c_type == TS_END)) - Afile = -Afile; - if (Afile > 0) { + if (! AfileActive && isspcl && (spcl.c_type == TS_END)) + AfileActive = 1; + if (AfileActive && Afile >= 0 && !(spcl.c_flags & DR_EXTATTRIBUTES)) { /* When we dump an inode which is not a directory, * it means we ended the archive contents */ if (isspcl && (spcl.c_type == TS_INODE) && ((spcl.c_dinode.di_mode & S_IFMT) != IFDIR)) - Afile = -Afile; + AfileActive = 0; else { union u_spcl tmp; tmp = *(union u_spcl *)dp; @@ -265,9 +311,10 @@ writerec(const void *dp, int isspcl) } void -dumpblock(daddr_t blkno, int size) +dumpblock(blk_t blkno, int size) { - int avail, tpblks, dblkno; + int avail, tpblks; + ext2_loff_t dblkno; dblkno = fsbtodb(sblock, blkno); tpblks = size >> tp_bshift; @@ -311,7 +358,7 @@ tperror(int errnum) } static void -sigpipe(int signo) +sigpipe(UNUSED(int signo)) { quit("Broken pipe\n"); @@ -332,7 +379,7 @@ do_stats(void) blocks = spcl.c_tapea - tapea_volume; msg("Volume %d completed at: %s", tapeno, ctime(&tnow)); if (! compressed) - msg("Volume %d %ld tape blocks (%.2fMB)\n", tapeno, + msg("Volume %d %ld blocks (%.2fMB)\n", tapeno, blocks, ((double)blocks * TP_BSIZE / 1048576)); if (ttaken > 0) { long volkb = (bytes_written - tapea_bytes) / 1024; @@ -408,6 +455,10 @@ flushtape(void) int siz = (char *)nextblock - (char *)slp->req; + /* make sure returned has sane values in case we don't read + * them from the slave in this pass */ + returned.unclen = returned.clen = writesize; + slp->req[trecno].count = 0; /* Sentinel */ if (dump_atomic_write( slp->fd, (char *)slp->req, siz) != siz) @@ -463,10 +514,14 @@ flushtape(void) } blks = 0; - if (spcl.c_type != TS_END) { - for (i = 0; i < spcl.c_count; i++) - if (spcl.c_addr[i] != 0) - blks++; + if (spcl.c_type == TS_CLRI || spcl.c_type == TS_BITS) + blks = spcl.c_count; + else { + if (spcl.c_type != TS_END) { + for (i = 0; i < spcl.c_count; i++) + if (spcl.c_addr[i] != 0) + blks++; + } } slp->count = lastspclrec + blks + 1 - spcl.c_tapea; slp->tapea = spcl.c_tapea; @@ -478,9 +533,9 @@ flushtape(void) blockswritten += ntrec; blocksthisvol += ntrec; if (!pipeout && !unlimited) { - if (blocksperfile) { - if ( compressed ? (bytes_written - tapea_bytes + SLAVES * (writesize + sizeof(struct tapebuf))) >= blocksperfile * 1024 - : blocksthisvol >= blocksperfile ) { + if (blocksperfiles && blocksperfiles[blocksperfiles_current]) { + if ( compressed ? (bytes_written - tapea_bytes + SLAVES * (writesize + sizeof(struct tapebuf))) >= (((long long)blocksperfiles[blocksperfiles_current]) * 1024) + : blocksthisvol >= blocksperfiles[blocksperfiles_current] ) { close_rewind(); startnewtape(0); } @@ -542,7 +597,7 @@ trewind(void) #ifdef RDUMP if (host) { rmtclose(); - while (rmtopen(tape, "O_RDONLY") < 0) + while (rmtopen(tape, O_RDONLY) < 0) sleep(10); rmtclose(); } @@ -556,15 +611,6 @@ trewind(void) (void) close(f); } } - eot_code = 1; - if (eot_script && spcl.c_type != TS_END) { - msg("Launching %s\n", eot_script); - eot_code = system_command(eot_script, tape, tapeno); - } - if (eot_code != 0 && eot_code != 1) { - msg("Dump aborted by the end of tape script\n"); - dumpabort(0); - } } return do_stats(); } @@ -573,8 +619,19 @@ trewind(void) void close_rewind(void) { + int eot_code = 1; (void)trewind(); - if (nexttape || Mflag || (eot_code == 0) ) + if (eot_script) { + msg("Launching %s\n", eot_script); + eot_code = system_command(eot_script, tape, tapeno); + } + if (eot_code != 0 && eot_code != 1) { + msg("Dump aborted by the end of tape script\n"); + dumpabort(0); + } + if (eot_code == 0) + return; + if (nexttape || Mflag) return; if (!nogripe) { msg("Change Volumes: Mount volume #%d\n", tapeno+1); @@ -602,6 +659,10 @@ rollforward(void) tslp = &slaves[SLAVES]; ntb = (union u_spcl *)tslp->tblock[1]; + /* make sure returned has sane values in case we don't read + * them from the slave in this pass */ + returned.unclen = returned.clen = writesize; + /* * Each of the N slaves should have requests that need to * be replayed on the next tape. Use the extra slave buffers @@ -729,6 +790,16 @@ rollforward(void) #endif } +#ifdef __linux__ +#if defined(SYS_clone) && defined(CLONE_IO) +pid_t +fork_clone_io(void) +{ + return syscall(SYS_clone, CLONE_ARGS); +} +#endif +#endif + /* * We implement taking and restoring checkpoints on the tape level. * When each tape is opened, a new process is created by forking; this @@ -775,7 +846,7 @@ restore_check_point: /* * All signals are inherited... */ - childpid = fork(); + childpid = fork_clone_io(); if (childpid < 0) { msg("Context save fork fails in parent %d\n", parentpid); Exit(X_ABORT); @@ -863,8 +934,10 @@ restore_check_point: tape[MAXPATHLEN - 1] = '\0'; msg("Dumping volume %d on %s\n", tapeno, tape); } + if (blocksperfiles && blocksperfiles_current < *blocksperfiles) + blocksperfiles_current++; #ifdef RDUMP - while ((tapefd = (host ? rmtopen(tape, "O_WRONLY|O_CREAT|O_TRUNC") : pipeout ? + while ((tapefd = (host ? rmtopen(tape, O_WRONLY|O_CREAT|O_TRUNC) : pipeout ? fileno(stdout) : OPEN(tape, O_WRONLY|O_CREAT|O_TRUNC, 0666))) < 0) #else @@ -914,13 +987,13 @@ restore_check_point: if (tapeno > 1) msg("Volume %d begins with blocks from inode %d\n", tapeno, slp->inode); - if (tapeno < TP_NINOS) + if (tapeno < (int)TP_NINOS) volinfo[tapeno] = slp->inode; } } void -dumpabort(int signo) +dumpabort(UNUSED(int signo)) { if (master != 0 && master != getpid()) @@ -950,7 +1023,7 @@ Exit(int status) * proceed - handler for SIGUSR2, used to synchronize IO between the slaves. */ static void -proceed(int signo) +proceed(UNUSED(int signo)) { if (ready) siglongjmp(jmpbuf, 1); @@ -989,7 +1062,7 @@ enslave(void) } if (socketpair(AF_UNIX, SOCK_STREAM, 0, cmd) < 0 || - (slaves[i].pid = fork()) < 0) + (slaves[i].pid = fork_clone_io()) < 0) quit("too many slaves, %d (recompile smaller): %s\n", i, strerror(errno)); @@ -1011,7 +1084,11 @@ enslave(void) != sizeof i) quit("master/slave protocol botched 3\n"); #endif - doslave(cmd[0], i, (slaves[i].pid == slp->pid)); + doslave(cmd[0], +#ifdef WRITEDEBUG + i, +#endif + (slaves[i].pid == slp->pid)); Exit(X_FINOK); } else @@ -1057,20 +1134,25 @@ killall(void) * slaves. */ static void -doslave(int cmd, int slave_number, int first) +doslave(int cmd, +#ifdef WRITEDEBUG + int slave_number, +#endif + int first) { int nread; - int nextslave, size, eot_count, bufsize; - volatile int wrote = 0; - char *buffer; -#if defined(HAVE_ZLIB) || defined(HAVE_BZLIB) - struct tapebuf *comp_buf = NULL; - int compresult, do_compress = !first; + int nextslave; + volatile int wrote = 0, size, eot_count, bufsize; + char * volatile buffer; +#if defined(HAVE_ZLIB) || defined(HAVE_BZLIB) || defined(HAVE_LZO) + struct tapebuf * volatile comp_buf = NULL; + int compresult; + volatile int do_compress = !first; unsigned long worklen; -#ifdef HAVE_BZLIB - unsigned int worklen2; +#ifdef HAVE_LZO + lzo_align_t __LZO_MMODEL *LZO_WorkMem; #endif -#endif /* HAVE_ZLIB || HAVE_BZLIB */ +#endif /* HAVE_ZLIB || HAVE_BZLIB || HAVE_LZO */ struct slave_results returns; #ifdef __linux__ errcode_t retval; @@ -1079,6 +1161,9 @@ doslave(int cmd, int slave_number, int first) long long curtapepos; union u_spcl *uspclptr; struct s_spcl *spclptr; + /* long maxntrecs = 300000000 / (ntrec * 1024); last tested: 50 000 000 */ + long maxntrecs = 50000; /* every 50MB */ + long cntntrecs = maxntrecs; #endif /* USE_QFA */ sigset_t set; @@ -1095,7 +1180,7 @@ doslave(int cmd, int slave_number, int first) quit("slave couldn't reopen disk: %s\n", strerror(errno)); #ifdef __linux__ #ifdef BLKFLSBUF - (void)ioctl(diskfd, BLKFLSBUF); + (void)ioctl(diskfd, BLKFLSBUF, 0); #endif ext2fs_close(fs); retval = dump_fs_open(disk, &fs); @@ -1111,18 +1196,34 @@ doslave(int cmd, int slave_number, int first) quit("master/slave protocol botched - didn't get pid of next slave.\n"); } -#if defined(HAVE_ZLIB) || defined(HAVE_BZLIB) +#if defined(HAVE_ZLIB) || defined(HAVE_BZLIB) || defined(HAVE_LZO) /* if we're doing a compressed dump, allocate the compress buffer */ if (compressed) { - comp_buf = malloc(sizeof(struct tapebuf) + TP_BSIZE + writesize); + int bsiz = sizeof(struct tapebuf) + writesize; + /* Add extra space to deal with compression enlarging the buffer */ + if (TP_BSIZE > writesize/16 + 67) + bsiz += TP_BSIZE; + else + bsiz += writesize/16 + 67; + comp_buf = malloc(bsiz); if (comp_buf == NULL) quit("couldn't allocate a compress buffer.\n"); - if (bzipflag) - comp_buf->flags = COMPRESS_BZLIB; - else + if (zipflag == COMPRESS_ZLIB) comp_buf->flags = COMPRESS_ZLIB; + else if (zipflag == COMPRESS_BZLIB) + comp_buf->flags = COMPRESS_BZLIB; + else if (zipflag == COMPRESS_LZO) { + comp_buf->flags = COMPRESS_LZO; + if (lzo_init() != LZO_E_OK) quit("lzo_init failed\n"); + } else + quit("internal error - unknown compression method: %d\n", zipflag); } -#endif /* HAVE_ZLIB || HAVE_BZLIB */ +#ifdef HAVE_LZO + LZO_WorkMem = malloc(LZO1X_1_MEM_COMPRESS); + if (!LZO_WorkMem) + quit("couldn't allocate a compress buffer.\n"); +#endif +#endif /* HAVE_ZLIB || HAVE_BZLIB || HAVE_LZO */ /* * Get list of blocks to dump, read the blocks into tape buffer @@ -1151,7 +1252,7 @@ doslave(int cmd, int slave_number, int first) bufsize = writesize; /* length to write */ returns.clen = returns.unclen = bufsize; -#if defined(HAVE_ZLIB) || defined(HAVE_BZLIB) +#if defined(HAVE_ZLIB) || defined(HAVE_BZLIB) || defined(HAVE_LZO) /* * When writing a compressed dump, each block except * the first one on each tape is written @@ -1170,7 +1271,7 @@ doslave(int cmd, int slave_number, int first) worklen = TP_BSIZE + writesize; compresult = 1; #ifdef HAVE_ZLIB - if (!bzipflag) { + if (zipflag == COMPRESS_ZLIB) { compresult = compress2(comp_buf->buf, &worklen, (char *)slp->tblock[0], @@ -1183,8 +1284,8 @@ doslave(int cmd, int slave_number, int first) } #endif /* HAVE_ZLIB */ #ifdef HAVE_BZLIB - if (bzipflag) { - worklen2 = worklen; + if (zipflag == COMPRESS_BZLIB) { + unsigned int worklen2 = worklen; compresult = BZ2_bzBuffToBuffCompress( comp_buf->buf, &worklen2, @@ -1200,7 +1301,21 @@ doslave(int cmd, int slave_number, int first) } #endif /* HAVE_BZLIB */ - if (compresult && worklen <= (writesize - 16)) { +#ifdef HAVE_LZO + if (zipflag == COMPRESS_LZO) { + lzo_uint worklen2 = worklen; + compresult = lzo1x_1_compress((char *)slp->tblock[0],writesize, + comp_buf->buf, + &worklen2, + LZO_WorkMem); + worklen = worklen2; + if (compresult == LZO_E_OK) + compresult = 1; + else + compresult = 0; + } +#endif /* HAVE_LZO */ + if (compresult && worklen <= ((unsigned long)writesize - 16)) { /* write the compressed buffer */ comp_buf->length = worklen; comp_buf->compressed = 1; @@ -1219,7 +1334,7 @@ doslave(int cmd, int slave_number, int first) } /* compress the remaining blocks if we're compressing */ do_compress = compressed; -#endif /* HAVE_ZLIB || HAVE_BZLIB */ +#endif /* HAVE_ZLIB || HAVE_BZLIB || HAVE_LZO */ if (sigsetjmp(jmpbuf, 1) == 0) { ready = 1; @@ -1232,23 +1347,31 @@ doslave(int cmd, int slave_number, int first) #ifdef USE_QFA if (gTapeposfd >= 0) { int i; - int firstpass = 1; - for (i = 0; i < ntrec; ++i) { + int foundone = 0; + + for (i = 0; (i < ntrec) && !foundone; ++i) { uspclptr = (union u_spcl *)&slp->tblock[i]; spclptr = &uspclptr->s_spcl; if ((spclptr->c_magic == NFS_MAGIC) && - (spclptr->c_type == TS_INODE) && - ((spclptr->c_dinode.di_mode & S_IFMT) != IFDIR) && - (spclptr->c_date == gThisDumpDate)) { - /* if an error occured previously don't - * try again */ - if (firstpass) { - firstpass = 0; + (spclptr->c_type == TS_INODE) && + (spclptr->c_date == gThisDumpDate) && + !(spclptr->c_dinode.di_mode & S_IFDIR) && + !(spclptr->c_flags & DR_EXTATTRIBUTES) + ) { + foundone = 1; + /* if (cntntrecs >= maxntrecs) { only write every maxntrecs amount of data */ + cntntrecs = 0; if (gtperr == 0) gtperr = GetTapePos(&curtapepos); - } - if (gtperr == 0) - MkTapeString(spclptr, curtapepos); + /* if an error occured previously don't + * try again */ + if (gtperr == 0) { +#ifdef DEBUG_QFA + msg("inode %ld at tapepos %ld\n", spclptr->c_inumber, curtapepos); +#endif + gtperr = MkTapeString(spclptr, curtapepos); + } + /* } */ } } } @@ -1264,11 +1387,12 @@ doslave(int cmd, int slave_number, int first) #ifdef WRITEDEBUG printf("slave %d wrote %d\n", slave_number, wrote); #endif - if (wrote < 0) + if (wrote < 0 && errno != ENOSPC) break; - if (wrote == 0) + if (wrote == 0 || (wrote < 0 && errno == ENOSPC)) eot_count++; - size += wrote; + else + size += wrote; } #ifdef WRITEDEBUG @@ -1304,6 +1428,11 @@ doslave(int cmd, int slave_number, int first) * Signal the next slave to go. */ (void) kill(nextslave, SIGUSR2); +#ifdef USE_QFA + if (gTapeposfd >= 0) { + cntntrecs += ntrec; + } +#endif /* USE_QFA */ } if (nread != 0) quit("error reading command pipe: %s\n", strerror(errno)); @@ -1315,15 +1444,15 @@ doslave(int cmd, int slave_number, int first) * loop until the count is satisfied (or error). */ static ssize_t -dump_atomic_read(int fd, void *buf, size_t count) +dump_atomic_read(int fd, char *buf, size_t count) { int got, need = count; do { while ((got = read(fd, buf, need)) > 0 && (need -= got) > 0) - (char *)buf += got; + buf += got; } while (got == -1 && errno == EINTR); - return (got < 0 ? got : count - need); + return (got < 0 ? got : (ssize_t)count - need); } /* @@ -1332,19 +1461,39 @@ dump_atomic_read(int fd, void *buf, size_t count) * loop until the count is satisfied (or error). */ static ssize_t -dump_atomic_write(int fd, const void *buf, size_t count) +dump_atomic_write(int fd, const char *buf, size_t count) { int got, need = count; do { while ((got = write(fd, buf, need)) > 0 && (need -= got) > 0) - (char *)buf += got; + buf += got; } while (got == -1 && errno == EINTR); - return (got < 0 ? got : count - need); + return (got < 0 ? got : (ssize_t)count - need); } +/* +int +SetLogicalPos(void) +{ + int err = 0; + struct mt_pos buf; + + buf.mt_op = MTSETDRVBUFFER; + buf.mt_count = MT_ST_BOOLEANS | MT_ST_SCSI2LOGICAL; + if (ioctl(tapefd, MTIOCTOP, &buf) == -1) { + err = errno; + msg("[%ld] error: %d (setting logical)\n", + (unsigned long)getpid(), err); + } + return err; +} +*/ + #ifdef USE_QFA +#define LSEEK_GET_TAPEPOS 10 +#define LSEEK_GO2_TAPEPOS 11 /* * read the current tape position */ @@ -1355,7 +1504,7 @@ GetTapePos(long long *pos) #ifdef RDUMP if (host) { - *pos = (long long) rmtseek(0, SEEK_CUR); + *pos = (long long) rmtseek((OFF_T)0, (int)LSEEK_GET_TAPEPOS); err = *pos < 0; } else @@ -1381,8 +1530,10 @@ GetTapePos(long long *pos) return err; } -static void -MkTapeString(struct s_spcl *spclptr, long long curtapepos) { +static int +MkTapeString(struct s_spcl *spclptr, long long curtapepos) +{ + int err = 0; #ifdef DEBUG_QFA msg("inode %ld at tapepos %lld\n", spclptr->c_inumber, curtapepos); @@ -1393,8 +1544,10 @@ MkTapeString(struct s_spcl *spclptr, long long curtapepos) { tapeno, curtapepos); gTps[sizeof(gTps) - 1] = '\0'; - if (write(gTapeposfd, gTps, strlen(gTps)) != strlen(gTps)) { - warn("error writing tapepos file.\n"); + if (write(gTapeposfd, gTps, strlen(gTps)) != (ssize_t)strlen(gTps)) { + err = errno; + warn("error writing tapepos file. (error %d)\n", errno); } + return err; } #endif /* USE_QFA */