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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <knet.h>
include <mach.h>
include <config.h>
include "mtio.h"
# MT_UPDATE_LOCKFILE -- Update the current file position in the lockfile.
# This information is returned by the host specific driver at close time.
# We are called from a z-routine so we must access the lockfile using only
# low level OS interface routines to avoid recursion. We may be called during
# error recovery (as well as from a z-routine), so any errors are fatal.
procedure mt_update_lockfile (mt)
int mt #I device slot
extern mt_sync()
pointer sp, lockfile, tempfile, lbuf, ip, op, extn
int old_lockfile, new_lockfile, junk, status, nlines
errchk fmapfn
include "mtio.com"
define oline_ 91
define err_ 92
begin
call smark (sp)
call salloc (lockfile, SZ_PATHNAME, TY_CHAR)
call salloc (tempfile, SZ_PATHNAME, TY_CHAR)
call salloc (lbuf, SZ_LINE, TY_CHAR)
# Catch any errors in the following section and convert them
# into fatal errors.
iferr {
# Try to avoid generating any non-host legal filenames in the
# following code, to avoid any need to access the VFN mapping
# file. Generate temp file in the same directory on the same
# node as the lockfile so that we can easily rename the tempfile
# to be the new lockfile.
#call mt_lockname (MT_LKNAME(mt), Memc[lockfile], SZ_PATHNAME)
call strcpy (MT_LKNAME(mt), Memc[lockfile], SZ_PATHNAME)
# Make tempfile name.
extn = NULL
op = tempfile
for (ip=lockfile; Memc[ip] != EOS; ip=ip+1) {
if (Memc[ip] == '.')
extn = op
Memc[op] = Memc[ip]
op = op + 1
}
if (extn == NULL)
extn = op
call strcpy (".tlk", Memc[extn], 4)
# Map the filenames.
call fmapfn (Memc[tempfile], Memc[tempfile], SZ_PATHNAME)
call fmapfn (Memc[lockfile], Memc[lockfile], SZ_PATHNAME)
} then
goto err_
# Overwrite any existing tempfile.
call zfdele (Memc[tempfile], junk)
call zopntx (Memc[tempfile], NEW_FILE, new_lockfile)
if (new_lockfile == ERR)
goto err_
# Open old lockfile, if any, and copy the comments section.
call zopntx (Memc[lockfile], READ_ONLY, old_lockfile)
if (old_lockfile == ERR) {
oline_ call strcpy ("# Magtape unit ", Memc[lbuf], SZ_LINE)
call strcat (MT_DEVICE(mt), Memc[lbuf], SZ_LINE)
call strcat (" status\n", Memc[lbuf], SZ_LINE)
call mt_putline (new_lockfile, Memc[lbuf])
} else {
nlines = 0
repeat {
call zgettx (old_lockfile, Memc[lbuf], SZ_LINE, status)
if (status <= 0) {
if (nlines == 0) {
call zclstx (old_lockfile, status)
goto oline_
} else
break
} else
nlines = nlines + 1
Memc[lbuf+status] = EOS
if (Memc[lbuf] == '#')
call mt_putline (new_lockfile, Memc[lbuf])
} until (Memc[lbuf] != '#')
call zclstx (old_lockfile, status)
}
# Everything else we write from here on is new stuff. Discard rest
# of old lockfile.
# Save current file and record numbers.
if (MT_FILNO(mt) == -1)
MT_RECNO(mt) = -1
call mt_savekeyword (new_lockfile, "file", MT_FILNO(mt))
if (MT_NFILES(mt) > 0 && (MT_FILNO(mt) == MT_NFILES(mt) + 1))
call mt_putline (new_lockfile, " (EOT)")
call mt_putline (new_lockfile, "\n")
call mt_savekeyword (new_lockfile, "record", MT_RECNO(mt))
call mt_putline (new_lockfile, "\n")
call mt_savekeyword (new_lockfile, "nfiles", MT_NFILES(mt))
call mt_putline (new_lockfile, "\n")
call mt_savekeyword (new_lockfile, "tapeused", MT_TAPEUSED(mt))
call mt_putline (new_lockfile, "\n")
call mt_savekeyword (new_lockfile, "pflags", MT_PFLAGS(mt))
call mt_putline (new_lockfile, "\n")
# Install the new lockfile.
call zflstx (new_lockfile, status)
if (status == ERR)
goto err_
call zclstx (new_lockfile, status)
if (status == ERR)
goto err_
call zfdele (Memc[lockfile], status)
call zfrnam (Memc[tempfile], Memc[lockfile], status)
if (status == ERR)
goto err_
call sfree (sp)
return
err_
# If an error of any sort occurs, it is fatal.
call onerror_remove (mt_sync)
call zfdele (Memc[tempfile], status)
call zfdele (Memc[lockfile], status)
call fatal (0, "Fatal error writing magtape device lockfile")
end
# MT_SAVEKEYWORD -- Write a "keyword = value" status line into the lockfile.
procedure mt_savekeyword (fd, keyword, value)
int fd # output file
char keyword[ARB] # name of keyword
int value # value of keyword
char numbuf[MAX_DIGITS]
int junk, itoc()
begin
junk = itoc (value, numbuf, MAX_DIGITS)
call mt_putline (fd, keyword)
call mt_putline (fd, " = ")
call mt_putline (fd, numbuf)
end
# MT_PUTLINE -- Put a text string to the lockfile. Do not write line
# to lockfile until a newline is seen.
procedure mt_putline (fd, text)
int fd
char text[ARB]
extern mt_sync()
char lbuf[SZ_LINE]
int ip, op, status
data op /1/
begin
for (ip=1; text[ip] != EOS; ip=ip+1) {
lbuf[op] = text[ip]
op = min (SZ_LINE, op) + 1
if (text[ip] == '\n') {
call zputtx (fd, lbuf, op-1, status)
if (status == ERR) {
call onerror_remove (mt_sync)
call fatal (0,
"Fatal error writing magtape device lockfile")
}
op = 1
}
}
end
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