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-rw-r--r--defs.h6
-rw-r--r--fs.c170
-rw-r--r--proc.c13
-rw-r--r--sysfile.c67
4 files changed, 135 insertions, 121 deletions
diff --git a/defs.h b/defs.h
index 074ad84..f2f8d73 100644
--- a/defs.h
+++ b/defs.h
@@ -128,12 +128,14 @@ void itrunc(struct inode*);
void idecref(struct inode*);
struct inode* iincref(struct inode*);
void iput(struct inode*);
-struct inode* namei(char*, int, uint*, char**, 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* mknod1(struct inode*, char*, short, short, short);
+struct inode* dircreat(struct inode*, char*, int, short, short, short);
+int dirlookup(struct inode*, char*, int, uint*, uint*);
int unlink(char*);
void iupdate(struct inode*);
int link(char*, char*);
diff --git a/fs.c b/fs.c
index d8e6484..02ca8e9 100644
--- a/fs.c
+++ b/fs.c
@@ -465,7 +465,7 @@ writei(struct inode *ip, char *src, uint off, uint n)
// set *poff to the byte offset of the directory entry
// set *pinum to the inode number
// return 0.
-static int
+int
dirlookup(struct inode *dp, char *name, int namelen, uint *poff, uint *pinum)
{
uint off;
@@ -485,8 +485,10 @@ dirlookup(struct inode *dp, char *name, int namelen, uint *poff, uint *pinum)
if(memcmp(name, de->name, namelen) == 0 &&
(namelen == DIRSIZ || de->name[namelen]== 0)){
// entry matches path element
- *poff = off + (uchar*)de - bp->data;
- *pinum = de->inum;
+ if(poff)
+ *poff = off + (uchar*)de - bp->data;
+ if(pinum)
+ *pinum = de->inum;
brelse(bp);
return 0;
}
@@ -499,9 +501,9 @@ dirlookup(struct inode *dp, char *name, int namelen, uint *poff, uint *pinum)
// Write a new directory entry (name, ino) into the directory dp.
// Caller must have locked dp.
void
-dirwrite(struct inode *dp, char *name, uint ino)
+dirwrite(struct inode *dp, char *name, int namelen, uint ino)
{
- int i, off;
+ int off;
struct dirent de;
// Look for an empty dirent.
@@ -513,15 +515,37 @@ dirwrite(struct inode *dp, char *name, uint ino)
}
de.inum = ino;
- for(i = 0; i < DIRSIZ && name[i]; i++)
- de.name[i] = name[i];
- for(; i < DIRSIZ; i++)
- de.name[i] = '\0';
+ 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");
}
+// 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)
+{
+ struct inode *ip;
+
+ ip = ialloc(dp->dev, type);
+ if(ip == 0)
+ return 0;
+ ip->major = major;
+ ip->minor = minor;
+ ip->size = 0;
+ ip->nlink = 1;
+ iupdate(ip);
+
+ dirwrite(dp, name, namelen, ip->inum);
+
+ return ip;
+}
+
// Paths
// Skip over the next path element in path,
@@ -564,21 +588,13 @@ 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 mode, uint *ret_off,
- char **ret_last, struct inode **ret_ip)
+_namei(char *path, int parent, char **pname, int *pnamelen)
{
struct inode *dp;
char *name;
int namelen;
uint off, dev, inum;
- if(ret_off)
- *ret_off = 0xffffffff;
- if(ret_last)
- *ret_last = 0;
- if(ret_ip)
- *ret_ip = 0;
-
if(*path == '/')
dp = igetroot();
else {
@@ -593,83 +609,63 @@ namei(char *path, int mode, uint *ret_off,
if(dp->type != T_DIR)
goto fail;
-
- if(dirlookup(dp, name, namelen, &off, &inum) < 0){
- if(mode == NAMEI_CREATE && *path == '\0'){
- *ret_last = name;
- return dp;
- }
- goto fail;
- }
-
- if(mode == NAMEI_DELETE && *path == '\0'){
- // can't unlink . and ..
- if((namelen == 1 && memcmp(name, ".", 1) == 0) ||
- (namelen == 2 && memcmp(name, "..", 2) == 0)){
- goto fail;
- }
- *ret_off = off;
+
+ if(parent && *path == '\0'){
+ // Stop one level early.
+ *pname = name;
+ *pnamelen = namelen;
return dp;
}
+ if(dirlookup(dp, name, namelen, &off, &inum) < 0)
+ goto fail;
+
dev = dp->dev;
iput(dp);
dp = iget(dev, inum);
if(dp->type == 0 || dp->nlink < 1)
panic("namei");
}
-
- if(mode == NAMEI_LOOKUP)
- return dp;
- if(mode == NAMEI_CREATE && ret_ip){
- *ret_ip = dp;
+ if(parent)
return 0;
- }
- goto fail;
+ return dp;
fail:
iput(dp);
return 0;
}
-// 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)
+namei(char *path)
{
- struct inode *ip, *dp;
- char *last;
-
- if((dp = namei(path, NAMEI_CREATE, 0, &last, 0)) == 0)
- return 0;
-
- ip = mknod1(dp, last, type, major, minor);
-
- iput(dp);
-
- return ip;
+ return _namei(path, 0, 0, 0);
}
-// Create a new inode named name inside dp
-// and return its locked inode structure.
-// If name already exists, return 0.
struct inode*
-mknod1(struct inode *dp, char *name, short type, short major, short minor)
+nameiparent(char *path, char **name, int *namelen)
{
- struct inode *ip;
+ return _namei(path, 1, name, namelen);
+}
- ip = ialloc(dp->dev, type);
- if(ip == 0)
- return 0;
- ip->major = major;
- ip->minor = minor;
- ip->size = 0;
- ip->nlink = 1;
- iupdate(ip); // write new inode to disk
- dirwrite(dp, name, ip->inum);
+// 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;
+ if((dp = nameiparent(path, &name, &namelen)) == 0)
+ return 0;
+ if(dirlookup(dp, name, namelen, 0, 0) >= 0){
+ iput(dp);
+ return 0;
+ }
+ ip = dircreat(dp, name, namelen, type, major, minor);
+ iput(dp);
return ip;
}
@@ -680,12 +676,15 @@ unlink(char *path)
struct inode *ip, *dp;
struct dirent de;
uint off, inum, dev;
+ char *name;
+ int namelen;
- dp = namei(path, NAMEI_DELETE, &off, 0, 0);
- if(dp == 0)
+ if((dp = nameiparent(path, &name, &namelen)) == 0)
return -1;
-
- dev = dp->dev;
+ if(dirlookup(dp, name, namelen, &off, 0) < 0){
+ iput(dp);
+ return -1;
+ }
if(readi(dp, (char*)&de, off, sizeof(de)) != sizeof(de) || de.inum == 0)
panic("unlink no entry");
@@ -702,16 +701,13 @@ unlink(char *path)
if(writei(dp, (char*)&de, off, sizeof(de)) != sizeof(de))
panic("unlink dir write");
- iupdate(dp);
+ dev = dp->dev;
iput(dp);
ip = iget(dev, inum);
-
if(ip->nlink < 1)
panic("unlink nlink < 1");
-
ip->nlink--;
-
iupdate(ip);
iput(ip);
@@ -720,21 +716,26 @@ unlink(char *path)
// Create the path new as a link to the same inode as old.
int
-link(char *name1, char *name2)
+link(char *old, char *new)
{
struct inode *ip, *dp;
- char *last;
+ char *name;
+ int namelen;
- if((ip = namei(name1, NAMEI_LOOKUP, 0, 0, 0)) == 0)
+ if((ip = namei(old)) == 0)
return -1;
if(ip->type == T_DIR){
iput(ip);
return -1;
}
-
iunlock(ip);
-
- if((dp = namei(name2, NAMEI_CREATE, 0, &last, 0)) == 0) {
+
+ if((dp = nameiparent(new, &name, &namelen)) == 0){
+ idecref(ip);
+ return -1;
+ }
+ if(dirlookup(dp, name, namelen, 0, 0) >= 0){
+ iput(dp);
idecref(ip);
return -1;
}
@@ -744,11 +745,12 @@ link(char *name1, char *name2)
return -1;
}
+ // LOCKING ERROR HERE! TWO LOCKS HELD AT ONCE.
ilock(ip);
ip->nlink++;
iupdate(ip);
- dirwrite(dp, last, ip->inum);
+ dirwrite(dp, name, namelen, ip->inum);
iput(dp);
iput(ip);
diff --git a/proc.c b/proc.c
index 074dc17..b09b738 100644
--- a/proc.c
+++ b/proc.c
@@ -203,7 +203,6 @@ scheduler(void)
void
sched(void)
{
-
if(cp->state == RUNNING)
panic("sched running");
if(!holding(&proc_table_lock))
@@ -219,7 +218,6 @@ sched(void)
void
yield(void)
{
-
acquire(&proc_table_lock);
cp->state = RUNNABLE;
sched();
@@ -422,9 +420,10 @@ procdump(void)
[RUNNING] "run ",
[ZOMBIE] "zombie"
};
- int i;
+ int i, j;
struct proc *p;
char *state;
+ uint pc[10];
for(i = 0; i < NPROC; i++) {
p = &proc[i];
@@ -434,7 +433,13 @@ procdump(void)
state = states[p->state];
else
state = "???";
- cprintf("%d %s %s\n", p->pid, state, p->name);
+ cprintf("%d %s %s", p->pid, state, p->name);
+ if(p->state == SLEEPING) {
+ getcallerpcs((uint*)p->jmpbuf.ebp+2, pc);
+ for(j=0; j<10 && pc[j] != 0; j++)
+ cprintf(" %p", pc[j]);
+ }
+ cprintf("\n");
}
}
diff --git a/sysfile.c b/sysfile.c
index e5d4eae..cd00494 100644
--- a/sysfile.c
+++ b/sysfile.c
@@ -115,34 +115,41 @@ int
sys_open(void)
{
struct inode *ip, *dp;
- char *path;
+ char *path, *name;
+ int namelen;
int omode;
- int fd;
+ int fd, dev;
+ uint inum;
struct file *f;
- char *last;
if(argstr(0, &path) < 0 || argint(1, &omode) < 0)
return -1;
- if(omode & O_CREATE){
- dp = namei(path, NAMEI_CREATE, 0, &last, &ip);
- if(dp){
- ip = mknod1(dp, last, T_FILE, 0, 0);
- iput(dp);
- if(ip == 0)
- return -1;
- } else if(ip == 0){
+ switch(omode & O_CREATE){
+ default:
+ case 0: // regular open
+ if((ip = namei(path)) == 0)
return -1;
- } else if(ip->type == T_DIR){
- iput(ip);
+ break;
+
+ case O_CREATE:
+ if((dp = nameiparent(path, &name, &namelen)) == 0)
return -1;
+ if(dirlookup(dp, name, namelen, 0, &inum) >= 0){
+ dev = dp->dev;
+ iput(dp);
+ ip = iget(dev, inum);
+ }else{
+ if((ip = dircreat(dp, name, namelen, T_FILE, 0, 0)) == 0){
+ iput(dp);
+ return -1;
+ }
+ iput(dp);
}
- } else {
- ip = namei(path, NAMEI_LOOKUP, 0, 0, 0);
- if(ip == 0)
- return -1;
+ break;
}
- if(ip->type == T_DIR && ((omode & O_RDWR) || (omode & O_WRONLY))){
+
+ if(ip->type == T_DIR && (omode & (O_RDWR|O_WRONLY|O_CREATE))){
iput(ip);
return -1;
}
@@ -201,18 +208,22 @@ sys_mkdir(void)
{
struct inode *nip;
struct inode *dp;
- char *path;
+ char *name, *path;
struct dirent de;
- char *last;
+ int namelen;
if(argstr(0, &path) < 0)
return -1;
- dp = namei(path, NAMEI_CREATE, 0, &last, 0);
+ dp = nameiparent(path, &name, &namelen);
if(dp == 0)
return -1;
+ if(dirlookup(dp, name, namelen, 0, 0) >= 0){
+ iput(dp);
+ return -1;
+ }
- nip = mknod1(dp, last, T_DIR, 0, 0);
+ nip = dircreat(dp, name, namelen, T_DIR, 0, 0);
if(nip == 0){
iput(dp);
return -1;
@@ -245,22 +256,17 @@ sys_chdir(void)
if(argstr(0, &path) < 0)
return -1;
- if((ip = namei(path, NAMEI_LOOKUP, 0, 0, 0)) == 0)
+ if((ip = namei(path)) == 0)
return -1;
- if(ip == cp->cwd) {
- iput(ip);
- return 0;
- }
-
if(ip->type != T_DIR) {
iput(ip);
return -1;
}
+ iunlock(ip);
idecref(cp->cwd);
cp->cwd = ip;
- iunlock(cp->cwd);
return 0;
}
@@ -324,8 +330,7 @@ sys_exec(void)
if(argstr(0, &path) < 0 || argint(1, (int*)&argv) < 0)
return -1;
- ip = namei(path, NAMEI_LOOKUP, 0, 0, 0);
- if(ip == 0)
+ if((ip = namei(path)) == 0)
return -1;
if(readi(ip, (char*)&elf, 0, sizeof(elf)) < sizeof(elf))
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