patch-2.1.74 linux/fs/ntfs/attr.c

• Lines: 520
• Date: Fri Dec 19 15:24:21 1997
• Orig file: v2.1.73/linux/fs/ntfs/attr.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.73/linux/fs/ntfs/attr.c linux/fs/ntfs/attr.c
@@ -0,0 +1,519 @@
+/*
+ *  attr.c
+ *
+ *  Copyright (C) 1996-1997 Martin von Löwis
+ *  Copyright (C) 1996-1997 Régis Duchesne
+ */
+
+#include "types.h"
+#include "struct.h"
+#include "attr.h"
+
+#include <errno.h>
+#include "macros.h"
+#include "support.h"
+#include "util.h"
+#include "super.h"
+#include "inode.h"
+
+/* Look if an attribute already exists in the inode, and if not, create it */
+static int 
+new_attr(ntfs_inode *ino,int type,void *name,int namelen,int *pos, int *found)
+{
+	int do_insert=0;
+	int i;
+
+	for(i=0;i<ino->attr_count;i++)
+	{
+		int n=min(namelen,ino->attrs[i].namelen);
+		int s=ntfs_uni_strncmp(ino->attrs[i].name,name,n);
+		/*
+		 * We assume that each attribute can be uniquely 
+		 * identified by inode
+		 * number, attribute type and attribute name.
+		 */
+		if(ino->attrs[i].type==type && ino->attrs[i].namelen==namelen && !s){
+			*found=1;
+			*pos=i;
+			return 0;
+		}
+		/* attributes are ordered by type, then by name */
+		if(ino->attrs[i].type>type || (ino->attrs[i].type==type && s==1)){
+			do_insert=1;
+			break;
+		}
+	}
+
+	/* re-allocate space */
+	if(ino->attr_count % 8 ==0)
+	{
+		ntfs_attribute* old=ino->attrs;
+		ino->attrs = (ntfs_attribute*)ntfs_malloc((ino->attr_count+8)*
+			     sizeof(ntfs_attribute));
+		if(old){
+			ntfs_memcpy(ino->attrs,old,ino->attr_count*sizeof(ntfs_attribute));
+			ntfs_free(old);
+		}
+	}
+	if(do_insert)
+		ntfs_memcpy(ino->attrs+i+1,ino->attrs+i,(ino->attr_count-i)*
+			    sizeof(ntfs_attribute));
+	ino->attr_count++;
+	ino->attrs[i].type=type;
+	ino->attrs[i].namelen=namelen;
+	ino->attrs[i].name=name;
+	*pos=i;
+	*found=0;
+	return 0;
+}
+
+int 
+ntfs_make_attr_resident(ntfs_inode *ino,ntfs_attribute *attr)
+{
+	int size=attr->size;
+	if(size>0){
+		/* FIXME: read data, free clusters */
+		return EOPNOTSUPP;
+	}
+	attr->resident=1;
+	return 0;
+}
+
+/* Store in the inode readable information about a run */
+static void
+ntfs_insert_run(ntfs_attribute *attr,int cnum,int cluster,int len)
+{
+	/* (re-)allocate space if necessary */
+	if(attr->d.r.len % 8 == 0) {
+		ntfs_runlist* old;
+		old=attr->d.r.runlist;
+		attr->d.r.runlist=ntfs_malloc((attr->d.r.len+8)*sizeof(ntfs_runlist));
+		if(old) {
+			ntfs_memcpy(attr->d.r.runlist,old,attr->d.r.len
+				    *sizeof(ntfs_runlist));
+			ntfs_free(old);
+		}
+	}
+	if(attr->d.r.len>cnum)
+		ntfs_memcpy(attr->d.r.runlist+cnum+1,attr->d.r.runlist+cnum,
+			    (attr->d.r.len-cnum)*sizeof(ntfs_runlist));
+	attr->d.r.runlist[cnum].cluster=cluster;
+	attr->d.r.runlist[cnum].len=len;
+	attr->d.r.len++;
+}
+
+int ntfs_extend_attr(ntfs_inode *ino, ntfs_attribute *attr, int *len,
+		int flags)
+{
+	int error=0;
+	ntfs_runlist *rl;
+	int rlen,cluster;
+	int clen;
+	if(attr->compressed)return EOPNOTSUPP;
+	if(attr->resident)return EOPNOTSUPP;
+	if(ino->record_count>1)return EOPNOTSUPP;
+	rl=attr->d.r.runlist;
+	rlen=attr->d.r.len-1;
+	if(rlen>=0)
+		cluster=rl[rlen].cluster+rl[rlen].len;
+	else
+		/* no preference for allocation space */
+		cluster=0;
+	/* round up to multiple of cluster size */
+	clen=(*len+ino->vol->clustersize-1)/ino->vol->clustersize;
+	/* FIXME: try to allocate smaller pieces */
+	error=ntfs_allocate_clusters(ino->vol,&cluster,&clen,
+				     flags|ALLOC_REQUIRE_SIZE);
+	if(error)return error;
+	attr->allocated+=clen;
+	*len=clen*ino->vol->clustersize;
+	/* contiguous chunk */
+	if(rlen>=0 && cluster==rl[rlen].cluster+rl[rlen].len){
+		rl[rlen].len+=clen;
+		return 0;
+	}
+	ntfs_insert_run(attr,rlen+1,cluster,*len);
+	return 0;
+}
+
+int
+ntfs_make_attr_nonresident(ntfs_inode *ino, ntfs_attribute *attr)
+{
+	void *data=attr->d.data;
+	int len=attr->size;
+	int error,alen;
+	ntfs_io io;
+	attr->d.r.len=0;
+	attr->d.r.runlist=0;
+	attr->resident=0;
+	attr->allocated=attr->initialized=0;
+	alen=len;
+	error=ntfs_extend_attr(ino,attr,&alen,ALLOC_REQUIRE_SIZE);
+	if(error)return error;/* FIXME: On error, restore old values */
+	io.fn_put=ntfs_put;
+	io.fn_get=ntfs_get;
+	io.param=data;
+	io.size=len;
+	io.do_read=0;
+	return ntfs_readwrite_attr(ino,attr,0,&io);
+}
+
+/* Resize the attribute to a newsize */
+int ntfs_resize_attr(ntfs_inode *ino, ntfs_attribute *attr, int newsize)
+{
+	int error=0;
+	int oldsize=attr->size;
+	int clustersize=ino->vol->clustersize;
+	int i,count,newlen,newcount;
+	ntfs_runlist *rl;
+
+	if(newsize==oldsize)
+		return 0;
+	/* modifying compressed attributes not supported yet */
+	if(attr->compressed)
+		/* extending is easy: just insert sparse runs */
+		return EOPNOTSUPP;
+	if(attr->resident){
+		void *v;
+		if(newsize>ino->vol->clustersize){
+			error=ntfs_make_attr_nonresident(ino,attr);
+			if(error)return error;
+			return ntfs_resize_attr(ino,attr,newsize);
+		}
+		v=attr->d.data;
+		if(newsize){
+			attr->d.data=ntfs_malloc(newsize);
+			if(!attr->d.data)
+				return ENOMEM;
+			ntfs_bzero(attr->d.data+oldsize,newsize);
+			ntfs_memcpy(attr->d.data,v,min(newsize,oldsize));
+		}else
+			attr->d.data=0;
+		ntfs_free(v);
+		attr->size=newsize;
+		return 0;
+	}
+	/* non-resident attribute */
+	rl=attr->d.r.runlist;
+	if(newsize<oldsize){
+		for(i=0,count=0;i<attr->d.r.len;i++){
+			if((count+rl[i].len)*clustersize>newsize)
+				break;
+			count+=rl[i].len;
+		}
+		newlen=i+1;
+		/* free unused clusters in current run, unless sparse */
+		newcount=count;
+		if(rl[i].cluster!=-1){
+			int rounded=newsize-count*clustersize;
+			rounded=(rounded+clustersize-1)/clustersize;
+			error=ntfs_deallocate_clusters(ino->vol,rl[i].cluster+rounded,
+						       rl[i].len-rounded);
+			if(error)
+				return error; /* FIXME: incomplete operation */
+			rl[i].len=rounded;
+			newcount=count+rounded;
+		}
+		/* free all other runs */
+		for(i++;i<attr->d.r.len;i++)
+			if(rl[i].cluster!=-1){
+				error=ntfs_deallocate_clusters(ino->vol,rl[i].cluster,rl[i].len);
+				if(error)
+					return error; /* FIXME: incomplete operation */
+			}
+		/* FIXME? free space for extra runs in memory */
+		attr->d.r.len=newlen;
+	}else{
+		newlen=newsize;
+		error=ntfs_extend_attr(ino,attr,&newlen,ALLOC_REQUIRE_SIZE);
+		if(error)return error; /* FIXME: incomplete */
+		newcount=newlen/clustersize;
+	}
+	/* fill in new sizes */
+	attr->allocated = newcount*clustersize;
+	attr->size = newsize;
+	attr->initialized = newsize;
+	if(!newsize)
+		error=ntfs_make_attr_resident(ino,attr);
+	return error;
+}
+
+int ntfs_create_attr(ntfs_inode *ino, int anum, char *aname, void *data,
+	int dsize, ntfs_attribute **rattr)
+{
+	void *name;
+	int namelen;
+	int found,i;
+	int error;
+	ntfs_attribute *attr;
+	if(dsize>ino->vol->mft_recordsize)
+		/* FIXME: non-resident attributes */
+		return EOPNOTSUPP;
+	if(aname){
+		namelen=strlen(aname);
+		name=ntfs_malloc(2*namelen);
+		ntfs_ascii2uni(name,aname,namelen);
+	}else{
+		name=0;
+		namelen=0;
+	}
+	new_attr(ino,anum,name,namelen,&i,&found);
+	if(found){
+		ntfs_free(name);
+		return EEXIST;
+	}
+	*rattr=attr=ino->attrs+i;
+	/* allocate a new number.
+	   FIXME: Should this happen on inode writeback?
+	   FIXME: extensions records not supported */
+	error=ntfs_allocate_attr_number(ino,&i);
+	if(error)
+		return error;
+	attr->attrno=i;
+
+	attr->resident=1;
+	attr->compressed=attr->cengine=0;
+	attr->size=attr->allocated=attr->initialized=dsize;
+
+	/* FIXME: INDEXED information should come from $AttrDef
+	   Currently, only file names are indexed */
+	if(anum==ino->vol->at_file_name){
+		attr->indexed=1;
+	}else
+		attr->indexed=0;
+	attr->d.data=ntfs_malloc(dsize);
+	ntfs_memcpy(attr->d.data,data,dsize);
+	return 0;
+}
+
+/* Non-resident attributes are stored in runs (intervals of clusters).
+ *
+ * This function stores in the inode readable information about a non-resident
+ * attribute.
+ */
+static int 
+ntfs_process_runs(ntfs_inode *ino,ntfs_attribute* attr,unsigned char *data)
+{
+	int startvcn,endvcn;
+	int vcn,cnum;
+	int cluster,len,ctype;
+	startvcn = NTFS_GETU64(data+0x10);
+	endvcn = NTFS_GETU64(data+0x18);
+
+	/* check whether this chunk really belongs to the end */
+	for(cnum=0,vcn=0;cnum<attr->d.r.len;cnum++)
+		vcn+=attr->d.r.runlist[cnum].len;
+	if(vcn!=startvcn)
+	{
+		ntfs_error("Problem with runlist in extended record\n");
+		return -1;
+	}
+	if(!endvcn)
+	{
+		endvcn = NTFS_GETU64(data+0x28)-1; /* allocated length */
+		endvcn /= ino->vol->clustersize;
+	}
+	data=data+NTFS_GETU16(data+0x20);
+	cnum=attr->d.r.len;
+	cluster=0;
+	for(vcn=startvcn; vcn<=endvcn; vcn+=len)
+	{
+		if(ntfs_decompress_run(&data,&len,&cluster,&ctype))
+			return -1;
+		if(ctype)
+			ntfs_insert_run(attr,cnum,-1,len);
+		else
+			ntfs_insert_run(attr,cnum,cluster,len);
+		cnum++;
+	}
+	return 0;
+}
+  
+/* Insert the attribute starting at attr in the inode ino */
+int ntfs_insert_attribute(ntfs_inode *ino, unsigned char* attrdata)
+{
+	int i,found;
+	int type;
+	short int *name;
+	int namelen;
+	void *data;
+	ntfs_attribute *attr;
+
+	type = NTFS_GETU32(attrdata);
+	namelen = NTFS_GETU8(attrdata+9);
+	/* read the attribute's name if it has one */
+	if(!namelen)
+		name=0;
+	else
+	{
+		/* 1 Unicode character fits in 2 bytes */
+		name=ntfs_malloc(2*namelen);
+		ntfs_memcpy(name,attrdata+NTFS_GETU16(attrdata+10),2*namelen);
+	}
+	new_attr(ino,type,name,namelen,&i,&found);
+	/* We can have in one inode two attributes with type 0x00000030 (File Name) 
+	   and without name */
+	if(found && /*FIXME*/type!=ino->vol->at_file_name)
+	{
+		ntfs_process_runs(ino,ino->attrs+i,attrdata);
+		return 0;
+	}
+	attr=ino->attrs+i;
+	attr->resident=NTFS_GETU8(attrdata+8)==0;
+	attr->compressed=NTFS_GETU16(attrdata+0xC);
+	attr->attrno=NTFS_GETU16(attrdata+0xE);
+  
+	if(attr->resident) {
+		attr->size=NTFS_GETU16(attrdata+0x10);
+		data=attrdata+NTFS_GETU16(attrdata+0x14);
+		attr->d.data = (void*)ntfs_malloc(attr->size);
+		ntfs_memcpy(attr->d.data,data,attr->size);
+		attr->indexed=NTFS_GETU16(attrdata+0x16);
+	}else{
+		attr->allocated=NTFS_GETU32(attrdata+0x28);
+		attr->size=NTFS_GETU32(attrdata+0x30);
+		attr->initialized=NTFS_GETU32(attrdata+0x38);
+		attr->cengine=NTFS_GETU16(attrdata+0x22);
+		if(attr->compressed)
+			attr->compsize=NTFS_GETU32(attrdata+0x40);
+		ino->attrs[i].d.r.runlist=0;
+		ino->attrs[i].d.r.len=0;
+		ntfs_process_runs(ino,attr,attrdata);
+	}
+	return 0;
+}
+
+/* process compressed attributes */
+int ntfs_read_compressed(ntfs_inode *ino, ntfs_attribute *attr, int offset,
+	ntfs_io *dest)
+{
+	int error=0;
+	int clustersize,l;
+	int s_vcn,rnum,vcn,cluster,len,chunk,got,cl1,l1,offs1,copied;
+	char *comp=0,*comp1;
+	char *decomp=0;
+	ntfs_io io;
+	ntfs_runlist *rl;
+
+	l=dest->size;
+	clustersize=ino->vol->clustersize;
+	/* starting cluster of potential chunk
+	   there are three situations:
+	   a) in a large uncompressable or sparse chunk, 
+	   s_vcn is in the middle of a run
+	   b) s_vcn is right on a run border
+	   c) when several runs make a chunk, s_vcn is before the chunks
+	*/
+	s_vcn=offset/clustersize;
+	/* round down to multiple of 16 */
+	s_vcn &= ~15;
+	rl=attr->d.r.runlist;
+	for(rnum=vcn=0;rnum<attr->d.r.len && vcn+rl->len<=s_vcn;rnum++,rl++)
+		vcn+=rl->len;
+	if(rnum==attr->d.r.len){
+		/* beyond end of file */
+		/* FIXME: check allocated/initialized */
+		dest->size=0;
+		return 0;
+	}
+	io.do_read=1;
+	io.fn_put=ntfs_put;
+	io.fn_get=0;
+	cluster=rl->cluster;
+	len=rl->len;
+	copied=0;
+	while(l){
+		chunk=0;
+		if(cluster==-1){
+			/* sparse cluster */
+			char *sparse=ntfs_calloc(512);
+			int l1;
+			if(!sparse)return ENOMEM;
+			if((len-(s_vcn-vcn)) & 15)
+				ntfs_error("unexpected sparse chunk size");
+			l1=chunk = min((vcn+len)*clustersize-offset,l);
+			while(l1){
+				int i=min(l1,512);
+				dest->fn_put(dest,sparse,i);
+				l1-=i;
+			}
+			ntfs_free(sparse);
+		}else if(dest->do_read){
+			if(!comp){
+				comp=ntfs_malloc(16*clustersize);
+				if(!comp){
+					error=ENOMEM;
+					goto out;
+				}
+			}
+			got=0;
+			/* we might need to start in the middle of a run */
+			cl1=cluster+s_vcn-vcn;
+			comp1=comp;
+			do{
+				io.param=comp1;
+				l1=min(len-max(s_vcn-vcn,0),16-got);
+				io.size=l1*clustersize;
+				error=ntfs_getput_clusters(ino->vol,cl1,0,&io);
+				if(error)goto out;
+				if(l1+max(s_vcn-vcn,0)==len){
+					rnum++;rl++;
+					vcn+=len;
+					cluster=cl1=rl->cluster;
+					len=rl->len;
+				}
+				got+=l1;
+				comp1+=l1*clustersize;
+			}while(cluster!=-1 && got<16); /* until empty run */
+			chunk=16*clustersize;
+			if(cluster!=-1 || got==16)
+				/* uncompressible */
+				comp1=comp;
+			else{
+				if(!decomp){
+					decomp=ntfs_malloc(16*clustersize);
+					if(!decomp){
+						error=ENOMEM;
+						goto out;
+					}
+				}
+				/* make sure there are null bytes
+				   after the last block */
+				*(ntfs_u32*)comp1=0;
+				ntfs_decompress(decomp,comp,chunk);
+				comp1=decomp;
+			}
+			offs1=offset-s_vcn*clustersize;
+			chunk=min(16*clustersize-offs1,chunk);
+			chunk=min(l,chunk);
+			dest->fn_put(dest,comp1+offs1,chunk);
+		}
+		l-=chunk;
+		copied+=chunk;
+		offset+=chunk;
+		s_vcn=offset/clustersize & ~15;
+		if(l && offset>=((vcn+len)*clustersize)){
+			rnum++;rl++;
+			vcn+=len;
+			cluster=rl->cluster;
+			len=rl->len;
+		}
+	}
+ out:
+	if(comp)ntfs_free(comp);
+	if(decomp)ntfs_free(decomp);
+	dest->size=copied;
+	return error;
+}
+
+int ntfs_write_compressed(ntfs_inode *ino, ntfs_attribute *attr, int offset,
+	ntfs_io *dest)
+{
+	return EOPNOTSUPP;
+}
+
+/*
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */