/*
* _any_sds_fr_mem moves data into a secondary data segment (SDS) from
* user memory
*
* unlike _sds_fr_mem, _any_sds_fr_mem handles moving a number of bits that
* may not be a multiple of 512.
*
* Returns 0 on normal return, or else -1 with error code in errno.
*/
_any_sds_fr_mem(
bitptr sdsaddr, /* SDS bit address of data */
bitptr ubuf, /* user buffer to receive data */
int nbits /* number of bits to move */
)
{
int sds_bit_offset;
int sds_bit_offset_blk;
int rbits;
char localbuf[BYTPBLOCK];
bitptr locptr;
long *uwaddr;
char *ucaddr;
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
if (sds_bit_offset & (BITPBLOCK -1)) {
/* The sds address is not on a block boundary. */
/* Read data from sds to a local buffer. Copy the */
/* user's memory to the appropriate part of the local */
/* buffer, and write it back out to sds. */
sds_bit_offset_blk = (sds_bit_offset & ~(BITPBLOCK - 1));
if (ssread((int *)localbuf, BITS2BLOCKS(sds_bit_offset_blk), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
rbits = MIN(nbits, BITPBLOCK - (sds_bit_offset -
sds_bit_offset_blk));
locptr = CPTR2BP(localbuf);
SET_BPTR(locptr, INC_BPTR(locptr, sds_bit_offset - sds_bit_offset_blk));
MOV_BITS(locptr, ubuf, rbits);
SET_BPTR(ubuf, INC_BPTR(ubuf, rbits));
nbits -= rbits;
if(sswrite((int *)localbuf, BITS2BLOCKS(sds_bit_offset_blk), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, rbits));
if (nbits == 0)
return(0);
assert(((SUBT_BPTR(sdsaddr, WPTR2BP(0))) & (BITPBLOCK -1)) == 0);
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
uwaddr = BPTR2WP(ubuf);
ucaddr = BPTR2CP(ubuf);
if ((nbits & (BITPBLOCK-1)) || (ucaddr != (char *)uwaddr)){
int left;
locptr = CPTR2BP(localbuf);
/* round down nbits to a block boundary */
rbits = nbits & ~(BITPBLOCK-1);
if (rbits) {
if (ucaddr != (char*)uwaddr) {
/* ubuf is not word aligned. */
left = rbits;
sds_bit_offset_blk = BITS2BLOCKS(sds_bit_offset);
while (left > 0) {
if( ssread((int *)localbuf,
sds_bit_offset_blk, 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
MOV_BITS(locptr, ubuf, BITPBLOCK);
SET_BPTR(ubuf, INC_BPTR(ubuf, BITPBLOCK));
if( sswrite((int *)localbuf,
sds_bit_offset_blk, 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, BITPBLOCK));
sds_bit_offset_blk++;
left-= BITPBLOCK;
}
}
else {
if (_sds_fr_mem(sdsaddr, ubuf, rbits) == -1) {
return(-1);
}
SET_BPTR(ubuf, INC_BPTR(ubuf, rbits));
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, rbits));
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
}
/* Get last block into local memory. Merge in user's memory */
/* and write it back out to sds. */
if( ssread((int *)localbuf, BITS2BLOCKS(sds_bit_offset), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
MOV_BITS(locptr, ubuf, nbits - rbits);
if( sswrite((int *)localbuf, BITS2BLOCKS(sds_bit_offset), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
}
else {
if(sswrite(uwaddr, BITS2BLOCKS(sds_bit_offset), BITS2BLOCKS(nbits)) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
}
return(0);
}
/*
* _cch_write
*
* Process write requests for the cache layer.
*
* Return value:
*
* The number of bytes transferred is returned upon successful completion.
* If an error occurs, -1 is returned.
*
* The stat->sw_stat field is set to FFCNT upon normal return.
*/
ssize_t
_cch_write(
struct fdinfo *fio, /* ffio file descriptor. */
bitptr datptr, /* bit pointer to the user's data. */
size_t nbytes, /* Nuber of bytes to be written. */
struct ffsw *stat, /* pointer to status return word */
int fulp, /* full or partial write mode flag */
int *ubcp /* pointer to unused bit count. On return, */
/* *ubcp is updated to contain the unused bit */
/* count in the data returned. */
)
{
off_t cpos; /* bit position in file */
int64 moved; /* number of bits transfered */
int64 bytes_moved; /* number of bytes transfered */
int64 morebits; /* bits moved in current iteration */
int64 numblocks; /* num of pages to process this iter */
int pgoff;
off_t fileaddr;
off_t eofaddr;
int gb_rd; /* nonzero if pages must be read */
int valid; /* nonzero if CCH_VALIDBUFFER should */
/* be set */
int64 nbits;
int64 i;
int bs, nbu;
off_t olpos, endpos, endoff;
bitptr toptr;
struct ffsw locstat;
struct fdinfo *llfio;
struct cch_f *cch_info;
struct cch_buf *cubuf;
int err;
short firsteof = 0;
short setfirst;
CCH_DEBUG(("_cch_write EN: nbytes=%d fulp=%d ubc=%d\n",nbytes,fulp,
*ubcp));
CLRSTAT(locstat);
cch_info = (struct cch_f *)fio->lyr_info;
nbits = BYTES2BITS(nbytes) - *ubcp;
fio->rwflag = WRITIN;
#if defined(__mips) || defined(_LITTLE_ENDIAN)
/* Although this layer is capable of handling non-zero ubc */
/* and bitptrs that aren't on a byte boundary, we are not */
/* supporting this right now on mips systems. */
if (*ubcp != 0) {
err = FDC_ERR_UBC;
goto err1_ret;
}
if ((BPBITOFF(datptr) & 07) != 0) {
err = FDC_ERR_REQ;
goto err1_ret;
}
#endif
if (nbits == 0) { /* quick return for nbits == 0*/
SETSTAT(stat, FFCNT, 0);
return(0);
}
/*
* Move data from user to buffer
*/
llfio = fio->fioptr;
bs = cch_info->bsize; /* bit size of each buffer */
cpos = cch_info->cpos; /* current file position */
olpos = cpos; /* save original position */
fileaddr = CCHFLOOR(cpos,bs); /* bit offset within the file of the
* start of the current page */
if (cpos > cch_info->fsize) {
firsteof = 1;
/* Is the page with eof in memory? */
/* If so, zero out the portion beyond eof. */
eofaddr = CCHFLOOR(cch_info->fsize, bs);
CCH_FINDBLK(cch_info, eofaddr, cubuf);
if (cubuf != NULL && (cubuf->flags & CCH_ZEROED) == 0) {
#ifdef CCH_SDS_SUPPORTED
if (cch_info->optflags & CCHOPT_SDS) {
/* should never happen */
ERETURN(stat, FDC_ERR_INTERR, 0);
}
#endif
pgoff = cch_info->fsize - eofaddr; /* offset of eof */
/* within the page */
SET_BPTR(toptr, INC_BPTR(cubuf->buf, pgoff));
morebits = bs - pgoff;
if (morebits != 0) {
CCH_MEMCLEAR(toptr, morebits);
}
cubuf->flags |= CCH_ZEROED;
}
}
while (nbits > 0) {
/*
* Find the cache buffer assigned to the current page. If
* no buffer is currently assigned, then _cch_getblk assigns
* one.
*/
pgoff = cpos - fileaddr; /* offset within the page */
numblocks = 1; /* number of of pages to prcess
* in this iteration */
CCH_FINDBLK(cch_info, fileaddr, cubuf);
if (cubuf == NULL) { /* if data not buffer-resident*/
if (nbits > cch_info->bypasssize
#ifdef CCH_SDS_SUPPORTED
&& !(cch_info->optflags & CCHOPT_SDS)
#endif
) {
/* Maybe we can bypass buffering */
if ((morebits= _cch_bypass(cch_info, nbits, cpos,
datptr, fileaddr, 'w', llfio, &locstat))>0)
goto adjust;
else if (morebits < 0) {
/* Is it right to return the count */
/* in locstat? Because we might */
/* have read some data... */
goto er1;
}
/* we weren't able to bypass buffering */
}
morebits = nbits;
endpos = cpos + morebits; /*1 bit past the end*/
endoff = endpos - CCHFLOOR(endpos,bs);
if (endpos > fileaddr + bs) {
numblocks = (endpos-fileaddr-1)/bs + 1;
nbu = cch_info->nbufs;
/*
* Handle at most a cache full at a time
*/
if (numblocks > nbu) {
numblocks = nbu;
endpos = fileaddr + nbu * bs;
endoff = 0;
morebits = endpos - cpos;
}
}
/*
* It is possible that the first or last
* page must be read because the transfer
* fills only part of these pages. In each
* iteration, _cch_getblk requires that
* consecutive buffer pages must all be read,
* or else all be assigned without pre-reading.
* The following code breaks off the current
* portion of the transfer when necessary to
* accomplish this.
*/
if (numblocks > 1) {
if (numblocks == 2) {
if ((pgoff == 0) != (endoff == 0)) {
/* process only first page */
numblocks = 1;
endoff = 0;
morebits = bs - pgoff;
}
}
else {
if (pgoff) {
/* process only first page */
numblocks = 1;
endoff = 0;
morebits = bs - pgoff;
}
else if (endoff) {
/* process all but last page */
numblocks -= 1;
endoff = 0;
morebits -= endoff;
}
}
}
/*
* Request that _cch_getblk read in the file
* pages if partial pages of data will be
* written.
*/
gb_rd = (pgoff || endoff);
/* The pages will be valid if we do not */
/* have to read them. That's because */
/* we will be writing to the entire page */
/* The page will also be valid if we do read it */
valid = 1;
setfirst = 0;
if (gb_rd &&
#ifdef CCH_SDS_SUPPORTED
!(cch_info->optflags & CCHOPT_SDS) &&
#endif
(numblocks == 1) &&
((fileaddr+bs) < cch_info->feof) &&
(_CCH_ALIGN(pgoff) && _CCH_ALIGN(endoff))) {
/* do we really need to read the page in? */
/* if pgoff and endoff are properly aligned, */
/* we do not */
/* Note that if any part of the page is */
/* beyond feof, we want to read it in. */
/* That's because code in _cch_rdabuf */
/* that handles having a partially dirty */
/* page expects to be able to read the */
/* data preceding the dirty data */
gb_rd = 0;
valid = 0; /* the page will not be valid */
setfirst = 1;
}
cubuf = _cch_getblk(cch_info, llfio, fileaddr,
&numblocks, gb_rd, valid, &locstat);
if (cubuf == NULL) {
goto er1;
}
if (setfirst) {
cubuf->firstdata = pgoff;
if (endoff == 0)
cubuf->lastdata = bs;
else
cubuf->lastdata = endoff;
}
if (firsteof && pgoff != 0) {
/* There is a gap between the eof and */
/* this data. Zero it if necessary. */
if ((cubuf->flags & CCH_ZEROED) == 0) {
int zbits;
#ifdef CCH_SDS_SUPPORTED
if (cch_info->optflags & CCHOPT_SDS) {
/* should never happen */
ERETURN(stat, FDC_ERR_INTERR, 0);
}
#endif
if ((eofaddr == fileaddr)) {
/* the eof is on this page */
zbits = bs - (cch_info->fsize - eofaddr);
SET_BPTR(toptr, INC_BPTR(cubuf->buf,
(cch_info->fsize - eofaddr)));
}
else {
/* the eof is not on this page */
/* zero the entire page */
zbits = bs;
toptr = cubuf->buf;
}
CCH_MEMCLEAR(toptr, zbits);
cubuf->flags |= CCH_ZEROED;
}
}
morebits = MIN(nbits, bs * numblocks - pgoff);
/* remember the last buffer page for next time */
cch_info->cubuf = cubuf + numblocks - 1;
}
else {
morebits = MIN(nbits, bs - pgoff);
if (!(cubuf->flags & CCH_VALIDBUFFER)) {
/* The buffer is there, but it */
/* is not entirely valid, because */
/* we never read into it. */
/* We can continue to just dirty it, */
/* provided that the dirty part is */
/* contiguous, and is properly aligned */
endoff = pgoff + morebits;
if ((pgoff == cubuf->lastdata &&
_CCH_ALIGN(endoff))|| (endoff ==
cubuf->firstdata && _CCH_ALIGN(pgoff))
|| (pgoff >= cubuf->firstdata &&
endoff <= cubuf->lastdata)) {
cubuf->firstdata = MIN(pgoff,
cubuf->firstdata);
cubuf->lastdata = MAX(endoff,
cubuf->lastdata);
if (cubuf->firstdata == 0 &&
cubuf->lastdata == bs) {
cubuf->lastdata = 0;
cubuf->flags |=CCH_VALIDBUFFER;
}
} else {
/* We can't just keep on putting */
/* stuff in the buffer without */
/* prereading it. So, we will call */
/* _cch_rdabuf, which has the */
/* smarts to read only the non-dirty */
/* parts */
if (_cch_rdabuf(cch_info, llfio, cubuf,
BITS2BYTES(cch_info->bsize),
BITS2BYTES(cubuf->filead), 1, 's',
&locstat)) {
goto er1;
}
}
}
}
for (i=0; i<numblocks; i++) {
/* adjust last access time */
CCH_CHRONOMETER(cubuf[i],cch_info);
cubuf[i].flags |= CCH_DIRTY;
}
SET_BPTR(toptr, INC_BPTR(cubuf->buf, pgoff));
#ifdef CCH_SDS_SUPPORTED
if (cch_info->optflags & CCHOPT_SDS) {
if (_sds_fr_mem(toptr, datptr, morebits) == ERR)
ERETURN(stat, errno, 0);
}
else
_CCH_MOV_BITS(toptr, datptr, morebits); /* contiguous bufs */
#else
_CCH_MOV_BITS(toptr, datptr, morebits); /* contiguous bufs */
#endif
adjust:
SET_BPTR(datptr, INC_BPTR(datptr, morebits));
cpos += morebits;
nbits -= morebits;
fileaddr = CCHFLOOR(cpos,bs);
/* bit offset within the file of the page */
firsteof = 0;
if (cpos > cch_info->fsize) {
cch_info->fsize = cpos;
}
}
cch_info->cpos = cpos;
moved = cpos - olpos;
fio->recbits += moved;
bytes_moved = BITS2BYTES(moved);
SETSTAT(stat, FFCNT, bytes_moved);
return(bytes_moved);
err1_ret:
ERETURN(stat, err, 0);
er1:
*stat = locstat;
return(ERR);
}
