コード例 #1
0
/*
 * Return buffer with the contents of block "offset" from the beginning of
 * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
 * remaining space in the directory.
 */
int
cd9660_blkatoff(vnode_t vp, off_t offset, char **res, buf_t *bpp)
{
	struct iso_node *ip;
	register struct iso_mnt *imp;
	buf_t	bp;
	daddr_t lbn;
	int bsize, error;

	ip = VTOI(vp);
	imp = ip->i_mnt;
	lbn = lblkno(imp, offset);
	bsize = blksize(imp, ip, lbn);

	if ((bsize != imp->im_sector_size) &&
	    (offset & (imp->im_sector_size - 1)) == 0) {
		bsize = imp->im_sector_size;
	}

	if ( (error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), bsize, NOCRED, &bp)) ) {
		buf_brelse(bp);
		*bpp = NULL;
		return (error);
	}
	if (res)
		*res = (char *)0 + buf_dataptr(bp) + blkoff(imp, offset);
	*bpp = bp;
	
	return (0);
}
コード例 #2
0
ファイル: BTreeScanner.c プロジェクト: 0xffea/xnu
static int ReadMultipleNodes( BTScanState *theScanStatePtr )
{
	int						myErr = E_NONE;
	BTreeControlBlockPtr  	myBTreeCBPtr;
	daddr64_t				myPhyBlockNum;
	u_int32_t				myBufferSize;
	struct vnode *			myDevPtr;
	unsigned int			myBlockRun;
	u_int32_t				myBlocksInBufferCount;

	// release old buffer if we have one
	if ( theScanStatePtr->bufferPtr != NULL )
	{
	        buf_markinvalid(theScanStatePtr->bufferPtr);
		buf_brelse( theScanStatePtr->bufferPtr );
		theScanStatePtr->bufferPtr = NULL;
		theScanStatePtr->currentNodePtr = NULL;
	}
	
	myBTreeCBPtr = theScanStatePtr->btcb;
			
	// map logical block in catalog btree file to physical block on volume
	myErr = hfs_bmap(myBTreeCBPtr->fileRefNum, theScanStatePtr->nodeNum, 
	                 &myDevPtr, &myPhyBlockNum, &myBlockRun);
	if ( myErr != E_NONE )
	{
		goto ExitThisRoutine;
	}

	// bmap block run gives us the remaining number of valid blocks (number of blocks 
	// minus the first).  so if there are 10 valid blocks our run number will be 9.
	// blocks, in our case is the same as nodes (both are 4K)
	myBlocksInBufferCount = (theScanStatePtr->bufferSize / myBTreeCBPtr->nodeSize );
	myBufferSize = theScanStatePtr->bufferSize;
	if ( (myBlockRun + 1) < myBlocksInBufferCount )
	{
		myBufferSize = (myBlockRun + 1) * myBTreeCBPtr->nodeSize;
	}
	
	// now read blocks from the device 
	myErr = (int)buf_bread(myDevPtr, 
	                       myPhyBlockNum, 
	                       myBufferSize,  
	                       NOCRED, 
	                       &theScanStatePtr->bufferPtr );
	if ( myErr != E_NONE )
	{
		goto ExitThisRoutine;
	}

	theScanStatePtr->nodesLeftInBuffer = buf_count(theScanStatePtr->bufferPtr) / theScanStatePtr->btcb->nodeSize;
	theScanStatePtr->currentNodePtr = (BTNodeDescriptor *) buf_dataptr(theScanStatePtr->bufferPtr);

ExitThisRoutine:
	return myErr;
	
} /* ReadMultipleNodes */
コード例 #3
0
/*
;_______________________________________________________________________
;
; Routine:	ReadBitmapBlock
;
; Function:	Read in a bitmap block corresponding to a given allocation
;			block (bit).  Return a pointer to the bitmap block.
;
; Inputs:
;	vcb			--	Pointer to ExtendedVCB
;	bit			--	Allocation block whose bitmap block is desired
;
; Outputs:
;	buffer		--	Pointer to bitmap block corresonding to "block"
;	blockRef
;_______________________________________________________________________
*/
static OSErr ReadBitmapBlock(
	ExtendedVCB		*vcb,
	u_int32_t		bit,
	u_int32_t		**buffer,
	u_int32_t		*blockRef)
{
	OSErr			err;
	struct buf *bp = NULL;
	struct vnode *vp = NULL;
	daddr64_t block;
	u_int32_t blockSize;

	/*
	 * volume bitmap blocks are protected by the allocation file lock
	 */
	REQUIRE_FILE_LOCK(vcb->hfs_allocation_vp, false);	

	blockSize = (u_int32_t)vcb->vcbVBMIOSize;
	block = (daddr64_t)(bit / (blockSize * kBitsPerByte));

	if (vcb->vcbSigWord == kHFSPlusSigWord) {
		vp = vcb->hfs_allocation_vp;	/* use allocation file vnode */

	} else /* hfs */ {
		vp = VCBTOHFS(vcb)->hfs_devvp;	/* use device I/O vnode */
		block += vcb->vcbVBMSt;			/* map to physical block */
	}

	err = (int)buf_meta_bread(vp, block, blockSize, NOCRED, &bp);

	if (bp) {
		if (err) {
			buf_brelse(bp);
			*blockRef = 0;
			*buffer = NULL;
		} else {
			*blockRef = (u_int32_t)bp;
			*buffer = (u_int32_t *)buf_dataptr(bp);
		}
	}

	return err;
}
コード例 #4
0
/*
 * Convert a component of a pathname into a pointer to a locked inode.
 * This is a very central and rather complicated routine.
 * If the file system is not maintained in a strict tree hierarchy,
 * this can result in a deadlock situation (see comments in code below).
 *
 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
 * whether the name is to be looked up, created, renamed, or deleted.
 * When CREATE, RENAME, or DELETE is specified, information usable in
 * creating, renaming, or deleting a directory entry may be calculated.
 * If flag has LOCKPARENT or'ed into it and the target of the pathname
 * exists, lookup returns both the target and its parent directory locked.
 * When creating or renaming and LOCKPARENT is specified, the target may
 * not be ".".  When deleting and LOCKPARENT is specified, the target may
 * be "."., but the caller must check to ensure it does an vrele and iput
 * instead of two iputs.
 *
 * Overall outline of ufs_lookup:
 *
 *	check accessibility of directory
 *	look for name in cache, if found, then if at end of path
 *	  and deleting or creating, drop it, else return name
 *	search for name in directory, to found or notfound
 * notfound:
 *	if creating, return locked directory, leaving info on available slots
 *	else return error
 * found:
 *	if at end of path and deleting, return information to allow delete
 *	if at end of path and rewriting (RENAME and LOCKPARENT), lock target
 *	  inode and return info to allow rewrite
 *	if not at end, add name to cache; if at end and neither creating
 *	  nor deleting, add name to cache
 *
 * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode unlocked.
 */
int
cd9660_lookup(struct vnop_lookup_args *ap)
{
	register struct vnode *vdp;	/* vnode for directory being searched */
	register struct iso_node *dp;	/* inode for directory being searched */
	register struct iso_mnt *imp;	/* file system that directory is in */
	struct buf *bp;			/* a buffer of directory entries */
	struct iso_directory_record *ep = NULL;/* the current directory entry */
	int entryoffsetinblock;		/* offset of ep in bp's buffer */
	int saveoffset = 0;		/* offset of last directory entry in dir */
	int numdirpasses;		/* strategy for directory search */
	doff_t endsearch;		/* offset to end directory search */
	struct vnode *pdp;		/* saved dp during symlink work */
	struct vnode *tdp;		/* returned by cd9660_vget_internal */
	u_long bmask;			/* block offset mask */
	int lockparent;			/* 1 => lockparent flag is set */
	int wantparent;			/* 1 => wantparent or lockparent flag */
	int wantassoc;
	int error;
	ino_t ino = 0;
	int reclen;
	u_short namelen;
	int isoflags;
	char altname[ISO_RRIP_NAMEMAX];
	int res;
	int len;
	char *name;
	struct vnode **vpp = ap->a_vpp;
	struct componentname *cnp = ap->a_cnp;
	int flags = cnp->cn_flags;
	int nameiop = cnp->cn_nameiop;
	vfs_context_t ctx = cnp->cn_context;
	size_t altlen;
	
	bp = NULL;
	*vpp = NULL;
	vdp = ap->a_dvp;
	dp = VTOI(vdp);
	imp = dp->i_mnt;
	lockparent = flags & LOCKPARENT;
	wantparent = flags & (LOCKPARENT|WANTPARENT);
	wantassoc = 0;

	
	/*
	 * We now have a segment name to search for, and a directory to search.
	 *
	 * Before tediously performing a linear scan of the directory,
	 * check the name cache to see if the directory/name pair
	 * we are looking for is known already.
	 */
	if ((error = cache_lookup(vdp, vpp, cnp))) {
		if (error == ENOENT)
			return (error);
		return (0);
	}
	
	len = cnp->cn_namelen;
	name = cnp->cn_nameptr;
	altname[0] = '\0';
	/*
	 * A "._" prefix means, we are looking for an associated file
	 */
	if (imp->iso_ftype != ISO_FTYPE_RRIP &&
	    *name == ASSOCCHAR1 && *(name+1) == ASSOCCHAR2) {
		wantassoc = 1;
		len -= 2;
		name += 2;
	}
	/*
	 * Decode search name into UCS-2 (Unicode)
	 */
	if ((imp->iso_ftype == ISO_FTYPE_JOLIET) &&
	    !((len == 1 && *name == '.') || (flags & ISDOTDOT))) {
		int flags1 = UTF_PRECOMPOSED;

		(void) utf8_decodestr(name, len, (u_int16_t*) altname, &altlen,
					sizeof(altname), 0, flags1);
		name = altname;
		len = altlen;
	}
	/*
	 * If there is cached information on a previous search of
	 * this directory, pick up where we last left off.
	 * We cache only lookups as these are the most common
	 * and have the greatest payoff. Caching CREATE has little
	 * benefit as it usually must search the entire directory
	 * to determine that the entry does not exist. Caching the
	 * location of the last DELETE or RENAME has not reduced
	 * profiling time and hence has been removed in the interest
	 * of simplicity.
	 */
	bmask = imp->im_sector_size - 1;
	if (nameiop != LOOKUP || dp->i_diroff == 0 ||
	    dp->i_diroff > dp->i_size) {
		entryoffsetinblock = 0;
		dp->i_offset = 0;
		numdirpasses = 1;
	} else {
		dp->i_offset = dp->i_diroff;
		
		if ((entryoffsetinblock = dp->i_offset & bmask) &&
		    (error = cd9660_blkatoff(vdp, SECTOFF(imp, dp->i_offset), NULL, &bp)))
				return (error);
		numdirpasses = 2;
		iso_nchstats.ncs_2passes++;
	}
	endsearch = dp->i_size;
	
searchloop:
	while (dp->i_offset < endsearch) {
		/*
		 * If offset is on a block boundary,
		 * read the next directory block.
		 * Release previous if it exists.
		 */
		if ((dp->i_offset & bmask) == 0) {
			if (bp != NULL)
				buf_brelse(bp);
			if ( (error = cd9660_blkatoff(vdp, SECTOFF(imp,dp->i_offset), NULL, &bp)) )
				return (error);
			entryoffsetinblock = 0;
		}
		/*
		 * Get pointer to next entry.
		 */
		ep = (struct iso_directory_record *)
			((char *)0 + buf_dataptr(bp) + entryoffsetinblock);
		
		reclen = isonum_711(ep->length);
		if (reclen == 0) {
			/* skip to next block, if any */
			dp->i_offset =
			    (dp->i_offset & ~bmask) + imp->im_sector_size;
			continue;
		}
		
		if (reclen < ISO_DIRECTORY_RECORD_SIZE) {
			/* illegal entry, stop */
			break;
		}
		if (entryoffsetinblock + reclen > imp->im_sector_size) {
			/* entries are not allowed to cross sector boundaries */
			break;
		}
		namelen = isonum_711(ep->name_len);
		isoflags = isonum_711(ep->flags);
		
		if (reclen < ISO_DIRECTORY_RECORD_SIZE + namelen)
			/* illegal entry, stop */
			break;
		/*
		 * Check for a name match.
		 */
		if (imp->iso_ftype == ISO_FTYPE_RRIP) {
			if (isoflags & directoryBit)
				ino = isodirino(ep, imp);
			else
				ino = ((daddr_t)buf_blkno(bp) << imp->im_bshift) + entryoffsetinblock;
			dp->i_ino = ino;
			cd9660_rrip_getname(ep,altname,&namelen,&dp->i_ino,imp);
			if (namelen == cnp->cn_namelen
			    && !bcmp(name,altname,namelen))
				goto found;
			ino = 0;
		} else {
			if ((!(isoflags & associatedBit)) == !wantassoc) {
				if ((len == 1
				     && *name == '.')
				    || (flags & ISDOTDOT)) {
					if (namelen == 1
					    && ep->name[0] == ((flags & ISDOTDOT) ? 1 : 0)) {
						/*
						 * Save directory entry's inode number and
						 * release directory buffer.
						 */
						dp->i_ino = isodirino(ep, imp);
						goto found;
					}
					if (namelen != 1
					    || ep->name[0] != 0)
						goto notfound;
				} else if (imp->iso_ftype != ISO_FTYPE_JOLIET && !(res = isofncmp(name, len, ep->name, namelen))) {
					if ( isoflags & directoryBit )
						ino = isodirino(ep, imp);
					else
						ino = ((daddr_t)buf_blkno(bp) << imp->im_bshift) + entryoffsetinblock;
					saveoffset = dp->i_offset;
				} else if (imp->iso_ftype == ISO_FTYPE_JOLIET && !(res = ucsfncmp((u_int16_t*)name, len,
							    (u_int16_t*) ep->name, namelen))) {
					if ( isoflags & directoryBit )
						ino = isodirino(ep, imp);
					else
						ino = ((daddr_t)buf_blkno(bp) << imp->im_bshift) + entryoffsetinblock;
					saveoffset = dp->i_offset;
				} else if (ino)
					goto foundino;
#ifdef	NOSORTBUG	/* On some CDs directory entries are not sorted correctly */
				else if (res < 0)
					goto notfound;
				else if (res > 0 && numdirpasses == 2)
					numdirpasses++;
#endif
			}
		}
		dp->i_offset += reclen;
		entryoffsetinblock += reclen;
	} /* endwhile */
	
	if (ino) {
foundino:
		dp->i_ino = ino;
		if (saveoffset != dp->i_offset) {
			if (lblkno(imp, dp->i_offset) !=
			    lblkno(imp, saveoffset)) {
				if (bp != NULL)
					buf_brelse(bp);
				if ( (error = cd9660_blkatoff(vdp, SECTOFF(imp, saveoffset), NULL, &bp)) )
					return (error);
			}
			entryoffsetinblock = saveoffset & bmask;
			ep = (struct iso_directory_record *)
				((char *)0 + buf_dataptr(bp) + entryoffsetinblock);
			dp->i_offset = saveoffset;
		}
		goto found;
	}
notfound:
	/*
	 * If we started in the middle of the directory and failed
	 * to find our target, we must check the beginning as well.
	 */
	if (numdirpasses == 2) {
		numdirpasses--;
		dp->i_offset = 0;
		endsearch = dp->i_diroff;
		goto searchloop;
	}
	if (bp != NULL)
		buf_brelse(bp);

	/*
	 * Insert name into cache (as non-existent) if appropriate.
	 */
	if (cnp->cn_flags & MAKEENTRY)
		cache_enter(vdp, *vpp, cnp);
	return (ENOENT);
	
found:
	if (numdirpasses == 2)
		iso_nchstats.ncs_pass2++;
	
	/*
	 * Found component in pathname.
	 * If the final component of path name, save information
	 * in the cache as to where the entry was found.
	 */
	if ((flags & ISLASTCN) && nameiop == LOOKUP)
		dp->i_diroff = dp->i_offset;
	
	/*
	 * Step through the translation in the name.  We do not `iput' the
	 * directory because we may need it again if a symbolic link
	 * is relative to the current directory.  Instead we save it
	 * unlocked as "pdp".  We must get the target inode before unlocking
	 * the directory to insure that the inode will not be removed
	 * before we get it.  We prevent deadlock by always fetching
	 * inodes from the root, moving down the directory tree. Thus
	 * when following backward pointers ".." we must unlock the
	 * parent directory before getting the requested directory.
	 * There is a potential race condition here if both the current
	 * and parent directories are removed before the `iget' for the
	 * inode associated with ".." returns.  We hope that this occurs
	 * infrequently since we cannot avoid this race condition without
	 * implementing a sophisticated deadlock detection algorithm.
	 * Note also that this simple deadlock detection scheme will not
	 * work if the file system has any hard links other than ".."
	 * that point backwards in the directory structure.
	 */
	pdp = vdp;
	/*
	 * If ino is different from dp->i_ino,
	 * it's a relocated directory.
	 */
	if (flags & ISDOTDOT) {
		error = cd9660_vget_internal(vnode_mount(vdp), dp->i_ino, &tdp, NULL, NULL,
					     dp->i_ino != ino, ep,
					     vfs_context_proc(ctx));
		VTOI(tdp)->i_parent = VTOI(pdp)->i_number;
		buf_brelse(bp);

		*vpp = tdp;
	} else if (dp->i_number == dp->i_ino) {
		buf_brelse(bp);
		vnode_get(vdp);	/* we want ourself, ie "." */
		*vpp = vdp;
	} else {
	        error = cd9660_vget_internal(vnode_mount(vdp), dp->i_ino, &tdp, vdp, cnp,
			     dp->i_ino != ino, ep, vfs_context_proc(ctx));
		/* save parent inode number */
		VTOI(tdp)->i_parent = VTOI(pdp)->i_number;
		buf_brelse(bp);
		if (error)
			return (error);
		*vpp = tdp;
	}
	return (0);
}
コード例 #5
0
ファイル: spec_vnops.c プロジェクト: 0xffea/xnu
/*
 * Vnode op for write
 */
int
spec_write(struct vnop_write_args *ap)
{
	struct vnode *vp = ap->a_vp;
	struct uio *uio = ap->a_uio;
	struct buf *bp;
	daddr64_t bn;
	int bsize, blkmask, bscale;
	int io_sync;
	int devBlockSize=0;
	int n, on;
	int error = 0;
	dev_t dev;

#if DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("spec_write mode");
	if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg))
		panic("spec_write proc");
#endif

	switch (vp->v_type) {

	case VCHR:
		error = (*cdevsw[major(vp->v_rdev)].d_write)
			(vp->v_rdev, uio, ap->a_ioflag);
		return (error);

	case VBLK:
		if (uio_resid(uio) == 0)
			return (0);
		if (uio->uio_offset < 0)
			return (EINVAL);

		io_sync = (ap->a_ioflag & IO_SYNC);

		dev = (vp->v_rdev);

		devBlockSize = vp->v_specsize;
		if (devBlockSize > PAGE_SIZE)
			return(EINVAL);

	        bscale = PAGE_SIZE / devBlockSize;
		blkmask = bscale - 1;
		bsize = bscale * devBlockSize;
		

		do {
			bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ blkmask);
			on = uio->uio_offset % bsize;

			n = min((unsigned)(bsize - on), uio_resid(uio));

			/*
			 * Use buf_getblk() as an optimization IFF:
			 *
			 * 1)	We are reading exactly a block on a block
			 *	aligned boundary
			 * 2)	We know the size of the device from spec_open
			 * 3)	The read doesn't span the end of the device
			 *
			 * Otherwise, we fall back on buf_bread().
			 */
			if (n == bsize &&
			    vp->v_specdevsize != (u_int64_t)0 &&
			    (uio->uio_offset + (u_int64_t)n) > vp->v_specdevsize) {
			    /* reduce the size of the read to what is there */
			    n = (uio->uio_offset + (u_int64_t)n) - vp->v_specdevsize;
			}

			if (n == bsize)
			        bp = buf_getblk(vp, bn, bsize, 0, 0, BLK_WRITE);
			else
			        error = (int)buf_bread(vp, bn, bsize, NOCRED, &bp);

			/* Translate downstream error for upstream, if needed */
			if (!error)
				error = (int)buf_error(bp);
			if (error) {
				buf_brelse(bp);
				return (error);
			}
			n = min(n, bsize - buf_resid(bp));

			error = uiomove((char *)0 + buf_dataptr(bp) + on, n, uio);
			if (error) {
				buf_brelse(bp);
				return (error);
			}
			buf_markaged(bp);

			if (io_sync) 
			        error = buf_bwrite(bp);
			else {
			        if ((n + on) == bsize)
				        error = buf_bawrite(bp);
				else
				        error = buf_bdwrite(bp);
			}
		} while (error == 0 && uio_resid(uio) > 0 && n != 0);
		return (error);

	default:
		panic("spec_write type");
	}
	/* NOTREACHED */

	return (0);
}
コード例 #6
0
ファイル: spec_vnops.c プロジェクト: 0xffea/xnu
/*
 * Vnode op for read
 */
int
spec_read(struct vnop_read_args *ap)
{
	struct vnode *vp = ap->a_vp;
	struct uio *uio = ap->a_uio;
	struct buf *bp;
	daddr64_t bn, nextbn;
	long bsize, bscale;
	int devBlockSize=0;
	int n, on;
	int error = 0;
	dev_t dev;

#if DIAGNOSTIC
	if (uio->uio_rw != UIO_READ)
		panic("spec_read mode");
	if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg))
		panic("spec_read proc");
#endif
	if (uio_resid(uio) == 0)
		return (0);

	switch (vp->v_type) {

	case VCHR:
		error = (*cdevsw[major(vp->v_rdev)].d_read)
			(vp->v_rdev, uio, ap->a_ioflag);
		return (error);

	case VBLK:
		if (uio->uio_offset < 0)
			return (EINVAL);

		dev = vp->v_rdev;

		devBlockSize = vp->v_specsize;

		if (devBlockSize > PAGE_SIZE) 
			return (EINVAL);

	        bscale = PAGE_SIZE / devBlockSize;
		bsize = bscale * devBlockSize;

		do {
			on = uio->uio_offset % bsize;

			bn = (daddr64_t)((uio->uio_offset / devBlockSize) &~ (bscale - 1));
			
			if (vp->v_speclastr + bscale == bn) {
			        nextbn = bn + bscale;
				error = buf_breadn(vp, bn, (int)bsize, &nextbn,
					       (int *)&bsize, 1, NOCRED, &bp);
			} else
			        error = buf_bread(vp, bn, (int)bsize, NOCRED, &bp);

			vnode_lock(vp);
			vp->v_speclastr = bn;
			vnode_unlock(vp);

			n = bsize - buf_resid(bp);
			if ((on > n) || error) {
			        if (!error)
				        error = EINVAL;
				buf_brelse(bp);
				return (error);
			}
			n = min((unsigned)(n  - on), uio_resid(uio));

			error = uiomove((char *)0 + buf_dataptr(bp) + on, n, uio);
			if (n + on == bsize)
				buf_markaged(bp);
			buf_brelse(bp);
		} while (error == 0 && uio_resid(uio) > 0 && n != 0);
		return (error);

	default:
		panic("spec_read type");
	}
	/* NOTREACHED */

	return (0);
}
コード例 #7
0
/*
 * Balloc defines the structure of file system storage
 * by allocating the physical blocks on a device given
 * the inode and the logical block number in a file.
 */
ffs_balloc(
	register struct inode *ip,
	register ufs_daddr_t lbn,
	int size,
	kauth_cred_t cred,
	struct buf **bpp,
	int flags,
	int * blk_alloc)
{
	register struct fs *fs;
	register ufs_daddr_t nb;
	struct buf *bp, *nbp;
	struct vnode *vp = ITOV(ip);
	struct indir indirs[NIADDR + 2];
	ufs_daddr_t newb, *bap, pref;
	int deallocated, osize, nsize, num, i, error;
	ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1];
	int devBlockSize=0;
	int alloc_buffer = 1;
	struct mount *mp=vp->v_mount;
#if REV_ENDIAN_FS
	int rev_endian=(mp->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */

	*bpp = NULL;
	if (lbn < 0)
		return (EFBIG);
	fs = ip->i_fs;
	if (flags & B_NOBUFF) 
		alloc_buffer = 0;

	if (blk_alloc)
		*blk_alloc = 0;

	/*
	 * If the next write will extend the file into a new block,
	 * and the file is currently composed of a fragment
	 * this fragment has to be extended to be a full block.
	 */
	nb = lblkno(fs, ip->i_size);
	if (nb < NDADDR && nb < lbn) {
		/* the filesize prior to this write  can fit in direct 
		 * blocks (ie.  fragmentaion is possibly done)
		 * we are now extending the file write beyond 
		 * the block which has end of file prior to this write 
		 */
		osize = blksize(fs, ip, nb); 
		/* osize gives disk allocated size in the last block. It is 
		 * either in fragments or a file system block size */
		if (osize < fs->fs_bsize && osize > 0) {
			/* few fragments are already allocated,since the
			 * current extends beyond this block 
			 * allocate the complete block as fragments are only
			 * in last block
			 */
			error = ffs_realloccg(ip, nb,
				ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
				osize, (int)fs->fs_bsize, cred, &bp);
			if (error)
				return (error);
			/* adjust the inode size we just grew */
			/* it is in nb+1 as nb starts from 0 */
			ip->i_size = (nb + 1) * fs->fs_bsize;
			ubc_setsize(vp, (off_t)ip->i_size);

			ip->i_db[nb] = dbtofsb(fs, (ufs_daddr_t)buf_blkno(bp));
			ip->i_flag |= IN_CHANGE | IN_UPDATE;

			if ((flags & B_SYNC) || (!alloc_buffer)) {
				if (!alloc_buffer) 
					buf_setflags(bp, B_NOCACHE);
				buf_bwrite(bp);
			} else
				buf_bdwrite(bp);
			/* note that bp is already released here */
		}
	}
	/*
	 * The first NDADDR blocks are direct blocks
	 */
	if (lbn < NDADDR) {
		nb = ip->i_db[lbn];
		if (nb != 0 && ip->i_size >= (lbn + 1) * fs->fs_bsize) {
			if (alloc_buffer) {
			error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), fs->fs_bsize, NOCRED, &bp);
			if (error) {
				buf_brelse(bp);
				return (error);
			}
			*bpp = bp;
			}
			return (0);
		}
		if (nb != 0) {
			/*
			 * Consider need to reallocate a fragment.
			 */
			osize = fragroundup(fs, blkoff(fs, ip->i_size));
			nsize = fragroundup(fs, size);
			if (nsize <= osize) {
				if (alloc_buffer) {
				error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), osize, NOCRED, &bp);
				if (error) {
					buf_brelse(bp);
					return (error);
				}
				ip->i_flag |= IN_CHANGE | IN_UPDATE;
				*bpp = bp;
				return (0);
				}
				else {
					ip->i_flag |= IN_CHANGE | IN_UPDATE;
					return (0);
				}
			} else {
				error = ffs_realloccg(ip, lbn,
				    ffs_blkpref(ip, lbn, (int)lbn,
					&ip->i_db[0]), osize, nsize, cred, &bp);
				if (error)
					return (error);
				ip->i_db[lbn] = dbtofsb(fs, (ufs_daddr_t)buf_blkno(bp));
				ip->i_flag |= IN_CHANGE | IN_UPDATE;

				/* adjust the inode size we just grew */
				ip->i_size = (lbn * fs->fs_bsize) + size;
				ubc_setsize(vp, (off_t)ip->i_size);

				if (!alloc_buffer) {
					buf_setflags(bp, B_NOCACHE);
					if (flags & B_SYNC)
						buf_bwrite(bp);
					else
						buf_bdwrite(bp);
				 } else
					*bpp = bp;
				return (0);

			}
		} else {
			if (ip->i_size < (lbn + 1) * fs->fs_bsize)
				nsize = fragroundup(fs, size);
			else
				nsize = fs->fs_bsize;
			error = ffs_alloc(ip, lbn,
			    ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]),
			    nsize, cred, &newb);
			if (error)
				return (error);
			if (alloc_buffer) {
			        bp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), nsize, 0, 0, BLK_WRITE);
				buf_setblkno(bp, (daddr64_t)((unsigned)fsbtodb(fs, newb)));

				if (flags & B_CLRBUF)
				        buf_clear(bp);
			}
			ip->i_db[lbn] = newb;
			ip->i_flag |= IN_CHANGE | IN_UPDATE;
			if (blk_alloc) {
				*blk_alloc = nsize;
			}
			if (alloc_buffer)
				*bpp = bp;
			return (0);
		}
	}
	/*
	 * Determine the number of levels of indirection.
	 */
	pref = 0;
	if (error = ufs_getlbns(vp, lbn, indirs, &num))
		return(error);
#if DIAGNOSTIC
	if (num < 1)
		panic ("ffs_balloc: ufs_bmaparray returned indirect block");
#endif
	/*
	 * Fetch the first indirect block allocating if necessary.
	 */
	--num;
	nb = ip->i_ib[indirs[0].in_off];
	allocib = NULL;
	allocblk = allociblk;
	if (nb == 0) {
		pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
	        if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
		    cred, &newb))
			return (error);
		nb = newb;
		*allocblk++ = nb;
		bp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[1].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
		buf_setblkno(bp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
		buf_clear(bp);
		/*
		 * Write synchronously conditional on mount flags.
		 */
		if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
			error = 0;
			buf_bdwrite(bp);
		} else if ((error = buf_bwrite(bp)) != 0) {
			goto fail;
		}
		allocib = &ip->i_ib[indirs[0].in_off];
		*allocib = nb;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * Fetch through the indirect blocks, allocating as necessary.
	 */
	for (i = 1;;) {
		error = (int)buf_meta_bread(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), (int)fs->fs_bsize, NOCRED, &bp);
		if (error) {
			buf_brelse(bp);
			goto fail;
		}
		bap = (ufs_daddr_t *)buf_dataptr(bp);
#if	REV_ENDIAN_FS
	if (rev_endian)
		nb = OSSwapInt32(bap[indirs[i].in_off]);
	else {
#endif	/* REV_ENDIAN_FS */
		nb = bap[indirs[i].in_off];
#if REV_ENDIAN_FS
	}
#endif /* REV_ENDIAN_FS */
		if (i == num)
			break;
		i += 1;
		if (nb != 0) {
			buf_brelse(bp);
			continue;
		}
		if (pref == 0)
			pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
		if (error =
		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
			buf_brelse(bp);
			goto fail;
		}
		nb = newb;
		*allocblk++ = nb;
		nbp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
		buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
		buf_clear(nbp);
		/*
		 * Write synchronously conditional on mount flags.
		 */
		if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
			error = 0;
			buf_bdwrite(nbp);
		} else if (error = buf_bwrite(nbp)) {
			buf_brelse(bp);
			goto fail;
		}
#if	REV_ENDIAN_FS
	if (rev_endian)
		bap[indirs[i - 1].in_off] = OSSwapInt32(nb);
	else {
#endif	/* REV_ENDIAN_FS */
		bap[indirs[i - 1].in_off] = nb;
#if	REV_ENDIAN_FS
	}
#endif	/* REV_ENDIAN_FS */
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		if (flags & B_SYNC) {
			buf_bwrite(bp);
		} else {
			buf_bdwrite(bp);
		}
	}
	/*
	 * Get the data block, allocating if necessary.
	 */
	if (nb == 0) {
		pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
		if (error = ffs_alloc(ip,
		    lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
			buf_brelse(bp);
			goto fail;
		}
		nb = newb;
		*allocblk++ = nb;
#if	REV_ENDIAN_FS
	if (rev_endian)
		bap[indirs[i].in_off] = OSSwapInt32(nb);
	else {
#endif	/* REV_ENDIAN_FS */
		bap[indirs[i].in_off] = nb;
#if	REV_ENDIAN_FS
	}
#endif	/* REV_ENDIAN_FS */
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		if ((flags & B_SYNC)) {
			buf_bwrite(bp);
		} else {
			buf_bdwrite(bp);
		}
		if(alloc_buffer ) {
		nbp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), fs->fs_bsize, 0, 0, BLK_WRITE);
		buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));

		if (flags & B_CLRBUF)
			buf_clear(nbp);
		}
		if (blk_alloc) {
			*blk_alloc = fs->fs_bsize;
		}
		if(alloc_buffer) 
			*bpp = nbp;

		return (0);
	}
	buf_brelse(bp);
	if (alloc_buffer) {
	        if (flags & B_CLRBUF) {
		        error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), (int)fs->fs_bsize, NOCRED, &nbp);
			if (error) {
			        buf_brelse(nbp);
				goto fail;
			}
		} else {
		        nbp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), fs->fs_bsize, 0, 0, BLK_WRITE);
			buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
		}
		*bpp = nbp;
	}
	return (0);
fail:
	/*
	 * If we have failed part way through block allocation, we
	 * have to deallocate any indirect blocks that we have allocated.
	 */
	for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
		ffs_blkfree(ip, *blkp, fs->fs_bsize);
		deallocated += fs->fs_bsize;
	}
	if (allocib != NULL)
		*allocib = 0;
	if (deallocated) {
	        devBlockSize = vfs_devblocksize(mp);
#if QUOTA
		/*
		 * Restore user's disk quota because allocation failed.
		 */
		(void) chkdq(ip, (int64_t)-deallocated, cred, FORCE);
#endif /* QUOTA */
		ip->i_blocks -= btodb(deallocated, devBlockSize);
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	return (error);
}
コード例 #8
0
/*
 * ffs_blkalloc allocates a disk block for ffs_pageout(), as a consequence
 * it does no buf_breads (that could lead to deadblock as the page may be already
 * marked busy as it is being paged out. Also important to note that we are not
 * growing the file in pageouts. So ip->i_size  cannot increase by this call
 * due to the way UBC works.  
 * This code is derived from ffs_balloc and many cases of that are  dealt
 * in ffs_balloc are not applicable here 
 * Do not call with B_CLRBUF flags as this should only be called only 
 * from pageouts
 */
ffs_blkalloc(
	struct inode *ip,
	ufs_daddr_t lbn,
	int size,
	kauth_cred_t cred,
	int flags)
{
	register struct fs *fs;
	register ufs_daddr_t nb;
	struct buf *bp, *nbp;
	struct vnode *vp = ITOV(ip);
	struct indir indirs[NIADDR + 2];
	ufs_daddr_t newb, *bap, pref;
	int deallocated, osize, nsize, num, i, error;
	ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1];
	int devBlockSize=0;
	struct mount *mp=vp->v_mount;
#if REV_ENDIAN_FS
	int rev_endian=(mp->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */

	fs = ip->i_fs;

	if(size > fs->fs_bsize)
		panic("ffs_blkalloc: too large for allocation");

	/*
	 * If the next write will extend the file into a new block,
	 * and the file is currently composed of a fragment
	 * this fragment has to be extended to be a full block.
	 */
	nb = lblkno(fs, ip->i_size);
	if (nb < NDADDR && nb < lbn) {
		panic("ffs_blkalloc():cannot extend file: i_size %d, lbn %d", ip->i_size, lbn);
	}
	/*
	 * The first NDADDR blocks are direct blocks
	 */
	if (lbn < NDADDR) {
		nb = ip->i_db[lbn];
		if (nb != 0 && ip->i_size >= (lbn + 1) * fs->fs_bsize) {
		/* TBD: trivial case; the block  is already allocated */
			return (0);
		}
		if (nb != 0) {
			/*
			 * Consider need to reallocate a fragment.
			 */
			osize = fragroundup(fs, blkoff(fs, ip->i_size));
			nsize = fragroundup(fs, size);
			if (nsize > osize) {
				panic("ffs_allocblk: trying to extend a fragment");
			}
			return(0);
		} else {
			if (ip->i_size < (lbn + 1) * fs->fs_bsize)
				nsize = fragroundup(fs, size);
			else
				nsize = fs->fs_bsize;
			error = ffs_alloc(ip, lbn,
			    ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]),
			    nsize, cred, &newb);
			if (error)
				return (error);
			ip->i_db[lbn] = newb;
			ip->i_flag |= IN_CHANGE | IN_UPDATE;
			return (0);
		}
	}
	/*
	 * Determine the number of levels of indirection.
	 */
	pref = 0;
	if (error = ufs_getlbns(vp, lbn, indirs, &num))
		return(error);

	if(num == 0) {
		panic("ffs_blkalloc: file with direct blocks only"); 
	}

	/*
	 * Fetch the first indirect block allocating if necessary.
	 */
	--num;
	nb = ip->i_ib[indirs[0].in_off];
	allocib = NULL;
	allocblk = allociblk;
	if (nb == 0) {
		pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
	        if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
		    cred, &newb))
			return (error);
		nb = newb;
		*allocblk++ = nb;
		bp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[1].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
		buf_setblkno(bp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
		buf_clear(bp);
		/*
		 * Write synchronously conditional on mount flags.
		 */
		if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
			error = 0;
			buf_bdwrite(bp);
		} else if (error = buf_bwrite(bp)) {
			goto fail;
		}
		allocib = &ip->i_ib[indirs[0].in_off];
		*allocib = nb;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * Fetch through the indirect blocks, allocating as necessary.
	 */
	for (i = 1;;) {
		error = (int)buf_meta_bread(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), (int)fs->fs_bsize, NOCRED, &bp);
		if (error) {
			buf_brelse(bp);
			goto fail;
		}
		bap = (ufs_daddr_t *)buf_dataptr(bp);
#if	REV_ENDIAN_FS
	if (rev_endian)
		nb = OSSwapInt32(bap[indirs[i].in_off]);
	else {
#endif	/* REV_ENDIAN_FS */
		nb = bap[indirs[i].in_off];
#if REV_ENDIAN_FS
	}
#endif /* REV_ENDIAN_FS */
		if (i == num)
			break;
		i += 1;
		if (nb != 0) {
			buf_brelse(bp);
			continue;
		}
		if (pref == 0)
			pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0);
		if (error =
		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
			buf_brelse(bp);
			goto fail;
		}
		nb = newb;
		*allocblk++ = nb;
		nbp = buf_getblk(vp, (daddr64_t)((unsigned)(indirs[i].in_lbn)), fs->fs_bsize, 0, 0, BLK_META);
		buf_setblkno(nbp, (daddr64_t)((unsigned)fsbtodb(fs, nb)));
		buf_clear(nbp);
		/*
		 * Write synchronously conditional on mount flags.
		 */
		if ((vp)->v_mount->mnt_flag & MNT_ASYNC) {
			error = 0;
			buf_bdwrite(nbp);
		} else if (error = buf_bwrite(nbp)) {
			buf_brelse(bp);
			goto fail;
		}
#if	REV_ENDIAN_FS
	if (rev_endian)
		bap[indirs[i - 1].in_off] = OSSwapInt32(nb);
	else {
#endif	/* REV_ENDIAN_FS */
		bap[indirs[i - 1].in_off] = nb;
#if	REV_ENDIAN_FS
	}
#endif	/* REV_ENDIAN_FS */
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		if (flags & B_SYNC) {
			buf_bwrite(bp);
		} else {
			buf_bdwrite(bp);
		}
	}
	/*
	 * Get the data block, allocating if necessary.
	 */
	if (nb == 0) {
		pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
		if (error = ffs_alloc(ip,
		    lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
			buf_brelse(bp);
			goto fail;
		}
		nb = newb;
		*allocblk++ = nb;
#if	REV_ENDIAN_FS
	if (rev_endian)
		bap[indirs[i].in_off] = OSSwapInt32(nb);
	else {
#endif	/* REV_ENDIAN_FS */
		bap[indirs[i].in_off] = nb;
#if	REV_ENDIAN_FS
	}
#endif	/* REV_ENDIAN_FS */
		/*
		 * If required, write synchronously, otherwise use
		 * delayed write.
		 */
		if (flags & B_SYNC) {
			buf_bwrite(bp);
		} else {
			buf_bdwrite(bp);
		}
		return (0);
	}
	buf_brelse(bp);
	return (0);
fail:
	/*
	 * If we have failed part way through block allocation, we
	 * have to deallocate any indirect blocks that we have allocated.
	 */
	for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
		ffs_blkfree(ip, *blkp, fs->fs_bsize);
		deallocated += fs->fs_bsize;
	}
	if (allocib != NULL)
		*allocib = 0;
	if (deallocated) {
	        devBlockSize = vfs_devblocksize(mp);
#if QUOTA
		/*
		 * Restore user's disk quota because allocation failed.
		 */
		(void) chkdq(ip, (int64_t)-deallocated, cred, FORCE);
#endif /* QUOTA */
		ip->i_blocks -= btodb(deallocated, devBlockSize);
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	return (error);
}
コード例 #9
0
ファイル: kern_physio.c プロジェクト: Andromeda-OS/Kernel
int
physio( void (*f_strategy)(buf_t), 
	buf_t bp,
	dev_t dev,
	int flags,
	u_int (*f_minphys)(buf_t),
	struct uio *uio,
	int blocksize)
{
	struct proc *p = current_proc();
	int error, i, buf_allocated, todo, iosize;
	int orig_bflags = 0;
	int64_t done;

	error = 0;
	flags &= B_READ | B_WRITE;
	buf_allocated = 0;

	/*
	 * [check user read/write access to the data buffer]
	 *
	 * Check each iov one by one.  Note that we know if we're reading or
	 * writing, so we ignore the uio's rw parameter.  Also note that if
	 * we're doing a read, that's a *write* to user-space.
	 */
	for (i = 0; i < uio->uio_iovcnt; i++) {
		if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
			user_addr_t base;
			user_size_t len;
			
			if (uio_getiov(uio, i, &base, &len) ||
				!useracc(base,
					len,
		    		(flags == B_READ) ? B_WRITE : B_READ))
			return (EFAULT);
		}
	}
	/*
	 * Make sure we have a buffer, creating one if necessary.
	 */
	if (bp == NULL) {
		bp = buf_alloc((vnode_t)0);
		buf_allocated = 1;
	} else
	        orig_bflags = buf_flags(bp);
	/*
	 * at this point we should have a buffer
	 * that is marked BL_BUSY... we either 
	 * acquired it via buf_alloc, or it was
	 * passed into us... if it was passed
	 * in, it needs to already be owned by
	 * the caller (i.e. BL_BUSY is set)
	 */
	assert(bp->b_lflags & BL_BUSY);

	/*
	 * [set up the fixed part of the buffer for a transfer]
	 */
	bp->b_dev = dev;
	bp->b_proc = p;

	/*
	 * [mark the buffer busy for physical I/O]
	 * (i.e. set B_PHYS (because it's an I/O to user
	 * memory, and B_RAW, because B_RAW is to be
	 * "Set by physio for raw transfers.", in addition
	 * to the read/write flag.)
	 */
        buf_setflags(bp, B_PHYS | B_RAW);

	/*
	 * [while there is data to transfer and no I/O error]
	 * Note that I/O errors are handled with a 'goto' at the bottom
	 * of the 'while' loop.
	 */
	while (uio_resid(uio) > 0) {
			
			if ( (iosize = uio_curriovlen(uio)) > MAXPHYSIO_WIRED)
			        iosize = MAXPHYSIO_WIRED;
			/*
			 * make sure we're set to issue a fresh I/O
			 * in the right direction
			 */
			buf_reset(bp, flags);

			/* [set up the buffer for a maximum-sized transfer] */
 			buf_setblkno(bp, uio_offset(uio) / blocksize);
			buf_setcount(bp, iosize);
			buf_setdataptr(bp, (uintptr_t)CAST_DOWN(caddr_t, uio_curriovbase(uio)));
			
			/*
			 * [call f_minphys to bound the tranfer size]
			 * and remember the amount of data to transfer,
			 * for later comparison.
			 */
			(*f_minphys)(bp);
			todo = buf_count(bp);

			/*
			 * [lock the part of the user address space involved
			 *    in the transfer]
			 */

			if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
				error = vslock(CAST_USER_ADDR_T(buf_dataptr(bp)),
					       (user_size_t)todo);
				if (error)
					goto done;
			}
			
			/* [call f_strategy to start the transfer] */
			(*f_strategy)(bp);


			/* [wait for the transfer to complete] */
			error = (int)buf_biowait(bp);

			/*
			 * [unlock the part of the address space previously
			 *    locked]
			 */
			if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg))
				vsunlock(CAST_USER_ADDR_T(buf_dataptr(bp)),
					 (user_size_t)todo,
					 (flags & B_READ));

			/*
			 * [deduct the transfer size from the total number
			 *    of data to transfer]
			 */
			done = buf_count(bp) - buf_resid(bp);
			uio_update(uio, done);

			/*
			 * Now, check for an error.
			 * Also, handle weird end-of-disk semantics.
			 */
			if (error || done < todo)
				goto done;
	}

done:
	if (buf_allocated)
	        buf_free(bp);
	else
		buf_setflags(bp, orig_bflags);

	return (error);
}