diff --git a/defs.h b/defs.h
index 24fd52b0631322668ca0dfbe249afe4b288bba2f..acf7b7c8a30522b293dafd8e449ebdc7c43361ea 100644
--- a/defs.h
+++ b/defs.h
@@ -121,24 +121,19 @@ void bwrite(struct buf*, uint);
void brelse(struct buf*);
// fs.c
+struct inode;
void iinit(void);
-struct inode* iget(uint, uint);
void ilock(struct inode*);
void iunlock(struct inode*);
-void itrunc(struct inode*);
void idecref(struct inode*);
struct inode* iincref(struct inode*);
void iput(struct inode*);
struct inode* namei(char*);
-struct inode* nameiparent(char*, char**, int*);
void stati(struct inode*, struct stat*);
int readi(struct inode*, char*, uint, uint);
int writei(struct inode*, char*, uint, uint);
struct inode* mknod(char*, short, short, short);
-struct inode* dircreat(struct inode*, char*, int, short, short, short);
-struct inode* dirlookup(struct inode*, char*, int, uint*);
int unlink(char*);
-void iupdate(struct inode*);
int link(char*, char*);
struct inode* igetroot(void);
int mkdir(char *path);
diff --git a/fs.c b/fs.c
index 4731b5f0aaabc05fc6c2109082fc78fe3f85c61d..8c65f35208de934ec64e1a7611224bfa5d2cc9ff 100644
--- a/fs.c
+++ b/fs.c
@@ -24,6 +24,8 @@
#include "dev.h"
#define min(a, b) ((a) < (b) ? (a) : (b))
+static void itrunc(struct inode*);
+static void iupdate(struct inode*);
// Blocks.
@@ -278,7 +280,7 @@ ialloc(uint dev, short type)
}
// Copy inode, which has changed, from memory to disk.
-void
+static void
iupdate(struct inode *ip)
{
struct buf *bp;
@@ -347,7 +349,7 @@ bmap(struct inode *ip, uint bn, int alloc)
}
// Truncate inode (discard contents).
-void
+static void
itrunc(struct inode *ip)
{
int i, j;
@@ -451,14 +453,41 @@ writei(struct inode *ip, char *src, uint off, uint n)
//
// Directories are just inodes (files) filled with dirent structures.
+// Compare two names, which are strings with a max length of DIRSIZ.
+static int
+namecmp(const char *s, const char *t)
+{
+ int i;
+
+ for(i=0; i<DIRSIZ; i++){
+ if(s[i] != t[i])
+ return s[i] - t[i];
+ if(s[i] == 0)
+ break;
+ }
+ return 0;
+}
+
+// Copy one name to another.
+static void
+namecpy(char *s, const char *t)
+{
+ int i;
+
+ for(i=0; i<DIRSIZ && t[i]; i++)
+ s[i] = t[i];
+ for(; i<DIRSIZ; i++)
+ s[i] = 0;
+}
+
// Look for a directory entry in a directory.
// If not found, return -1.
// If found:
// set *poff to the byte offset of the directory entry
// set *pinum to the inode number
// return 0.
-struct inode*
-dirlookup(struct inode *dp, char *name, int namelen, uint *poff)
+static struct inode*
+dirlookup(struct inode *dp, char *name, uint *poff)
{
uint off, inum;
struct buf *bp;
@@ -474,8 +503,7 @@ dirlookup(struct inode *dp, char *name, int namelen, uint *poff)
de++){
if(de->inum == 0)
continue;
- if(memcmp(name, de->name, namelen) == 0 &&
- (namelen == DIRSIZ || de->name[namelen]== 0)){
+ if(namecmp(name, de->name) == 0){
// entry matches path element
if(poff)
*poff = off + (uchar*)de - bp->data;
@@ -491,15 +519,15 @@ dirlookup(struct inode *dp, char *name, int namelen, uint *poff)
// Write a new directory entry (name, ino) into the directory dp.
// Caller must have locked dp.
-int
-dirlink(struct inode *dp, char *name, int namelen, uint ino)
+static int
+dirlink(struct inode *dp, char *name, uint ino)
{
int off;
struct dirent de;
struct inode *ip;
// Double-check that name is not present.
- if((ip = dirlookup(dp, name, namelen, 0)) != 0){
+ if((ip = dirlookup(dp, name, 0)) != 0){
idecref(ip);
return -1;
}
@@ -512,11 +540,8 @@ dirlink(struct inode *dp, char *name, int namelen, uint ino)
break;
}
+ namecpy(de.name, name);
de.inum = ino;
- if(namelen > DIRSIZ)
- namelen = DIRSIZ;
- memmove(de.name, name, namelen);
- memset(de.name+namelen, 0, DIRSIZ-namelen);
if(writei(dp, (char*)&de, off, sizeof(de)) != sizeof(de))
panic("dirwrite");
@@ -526,8 +551,8 @@ dirlink(struct inode *dp, char *name, int namelen, uint ino)
// Create a new inode named name inside dp
// and return its locked inode structure.
// If name already exists, return 0.
-struct inode*
-dircreat(struct inode *dp, char *name, int namelen, short type, short major, short minor)
+static struct inode*
+dircreat(struct inode *dp, char *name, short type, short major, short minor)
{
struct inode *ip;
@@ -541,7 +566,7 @@ dircreat(struct inode *dp, char *name, int namelen, short type, short major, sho
ip->nlink = 1;
iupdate(ip);
- if(dirlink(dp, name, namelen, ip->inum) < 0){
+ if(dirlink(dp, name, ip->inum) < 0){
ip->nlink = 0;
iupdate(ip);
iput(ip);
@@ -568,16 +593,25 @@ dircreat(struct inode *dp, char *name, int namelen, short type, short major, sho
// skipelem("") = skipelem("////") = 0
//
static char*
-skipelem(char *path, char **name, int *len)
+skipelem(char *path, char *name)
{
+ char *s;
+ int len;
+
while(*path == '/')
path++;
if(*path == 0)
return 0;
- *name = path;
+ s = path;
while(*path != '/' && *path != 0)
path++;
- *len = path - *name;
+ len = path - s;
+ if(len >= DIRSIZ)
+ memmove(name, s, DIRSIZ);
+ else{
+ memmove(name, s, len);
+ name[len] = 0;
+ }
while(*path == '/')
path++;
return path;
@@ -593,11 +627,9 @@ skipelem(char *path, char **name, int *len)
// NAMEI_DELETE: return locked parent inode, offset of dirent in *ret_off.
// return 0 if name doesn't exist.
struct inode*
-_namei(char *path, int parent, char **pname, int *pnamelen)
+_namei(char *path, int parent, char *name)
{
struct inode *dp, *ip;
- char *name;
- int namelen;
uint off;
if(*path == '/')
@@ -606,22 +638,16 @@ _namei(char *path, int parent, char **pname, int *pnamelen)
dp = iincref(cp->cwd);
ilock(dp);
- while((path = skipelem(path, &name, &namelen)) != 0){
- // Truncate names in path to DIRSIZ chars.
- if(namelen > DIRSIZ)
- namelen = DIRSIZ;
-
+ while((path = skipelem(path, name)) != 0){
if(dp->type != T_DIR)
goto fail;
if(parent && *path == '\0'){
// Stop one level early.
- *pname = name;
- *pnamelen = namelen;
return dp;
}
- if((ip = dirlookup(dp, name, namelen, &off)) == 0)
+ if((ip = dirlookup(dp, name, &off)) == 0)
goto fail;
iput(dp);
@@ -642,29 +668,27 @@ fail:
struct inode*
namei(char *path)
{
- return _namei(path, 0, 0, 0);
+ char name[DIRSIZ];
+ return _namei(path, 0, name);
}
-struct inode*
-nameiparent(char *path, char **name, int *namelen)
+static struct inode*
+nameiparent(char *path, char *name)
{
- return _namei(path, 1, name, namelen);
+ return _namei(path, 1, name);
}
-
-
// Create the path and return its locked inode structure.
// If cp already exists, return 0.
struct inode*
mknod(char *path, short type, short major, short minor)
{
struct inode *ip, *dp;
- char *name;
- int namelen;
+ char name[DIRSIZ];
- if((dp = nameiparent(path, &name, &namelen)) == 0)
+ if((dp = nameiparent(path, name)) == 0)
return 0;
- ip = dircreat(dp, name, namelen, type, major, minor);
+ ip = dircreat(dp, name, type, major, minor);
iput(dp);
return ip;
}
@@ -676,26 +700,21 @@ unlink(char *path)
struct inode *ip, *dp;
struct dirent de;
uint off;
- char *name;
- int namelen;
+ char name[DIRSIZ];
- if((dp = nameiparent(path, &name, &namelen)) == 0)
+ if((dp = nameiparent(path, name)) == 0)
return -1;
- if((ip = dirlookup(dp, name, namelen, &off)) == 0){
+
+ // Cannot unlink "." or "..".
+ if(namecmp(name, ".") == 0 || namecmp(name, "..") == 0){
iput(dp);
return -1;
}
- if(readi(dp, (char*)&de, off, sizeof(de)) != sizeof(de) || de.inum == 0)
- panic("unlink no entry");
-
- // Cannot remove "." or ".." - the 2 and 3 count the trailing NUL.
- if(memcmp(de.name, ".", 2) == 0 || memcmp(de.name, "..", 3) == 0){
- idecref(ip);
+ if((ip = dirlookup(dp, name, &off)) == 0){
iput(dp);
return -1;
}
-
memset(&de, 0, sizeof(de));
if(writei(dp, (char*)&de, off, sizeof(de)) != sizeof(de))
panic("unlink dir write");
@@ -716,8 +735,7 @@ int
link(char *old, char *new)
{
struct inode *ip, *dp;
- char *name;
- int namelen;
+ char name[DIRSIZ];
if((ip = namei(old)) == 0)
return -1;
@@ -727,11 +745,11 @@ link(char *old, char *new)
}
iunlock(ip);
- if((dp = nameiparent(new, &name, &namelen)) == 0){
+ if((dp = nameiparent(new, name)) == 0){
idecref(ip);
return -1;
}
- if(dp->dev != ip->dev || dirlink(dp, name, namelen, ip->inum) < 0){
+ if(dp->dev != ip->dev || dirlink(dp, name, ip->inum) < 0){
idecref(ip);
iput(dp);
return -1;
@@ -750,21 +768,20 @@ int
mkdir(char *path)
{
struct inode *dp, *ip;
- char *name;
- int namelen;
+ char name[DIRSIZ];
// XXX write ordering is screwy here- do we care?
- if((dp = nameiparent(path, &name, &namelen)) == 0)
+ if((dp = nameiparent(path, name)) == 0)
return -1;
- if((ip = dircreat(dp, name, namelen, T_DIR, 0, 0)) == 0){
+ if((ip = dircreat(dp, name, T_DIR, 0, 0)) == 0){
iput(dp);
return -1;
}
dp->nlink++;
iupdate(dp);
- if(dirlink(ip, ".", 1, ip->inum) < 0 || dirlink(ip, "..", 2, dp->inum) < 0)
+ if(dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0)
panic("mkdir");
iput(dp);
iput(ip);
@@ -776,13 +793,12 @@ struct inode*
create(char *path)
{
struct inode *dp, *ip;
- char *name;
- int namelen;
+ char name[DIRSIZ];
- if((dp = nameiparent(path, &name, &namelen)) == 0)
+ if((dp = nameiparent(path, name)) == 0)
return 0;
- if((ip = dirlookup(dp, name, namelen, 0)) != 0){
+ if((ip = dirlookup(dp, name, 0)) != 0){
iput(dp);
ilock(ip);
if(ip->type == T_DIR){
@@ -791,7 +807,7 @@ create(char *path)
}
return ip;
}
- if((ip = dircreat(dp, name, namelen, T_FILE, 0, 0)) == 0){
+ if((ip = dircreat(dp, name, T_FILE, 0, 0)) == 0){
iput(dp);
return 0;
}