summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorrtm <rtm>2006-08-25 01:11:30 +0000
committerrtm <rtm>2006-08-25 01:11:30 +0000
commit5051da6de3fcabb9e280d3bf36549da0ac0d5738 (patch)
tree9e93001ead271f31870c0896a409698309ff7f5d
parent74493bf4460f4024e06760289735e9d5dcb9dc3f (diff)
downloadxv6-labs-5051da6de3fcabb9e280d3bf36549da0ac0d5738.tar.gz
xv6-labs-5051da6de3fcabb9e280d3bf36549da0ac0d5738.tar.bz2
xv6-labs-5051da6de3fcabb9e280d3bf36549da0ac0d5738.zip
inode addrs[NDIRECT] -> NADDRS
fix race in mknod / creat use last component in dirent in mknod, not path
-rw-r--r--Notes5
-rw-r--r--defs.h3
-rw-r--r--fs.c73
-rw-r--r--fs.h2
-rw-r--r--fstests.c122
-rw-r--r--fsvar.h2
-rw-r--r--syscall.c32
7 files changed, 208 insertions, 31 deletions
diff --git a/Notes b/Notes
index 6273db5..54b93db 100644
--- a/Notes
+++ b/Notes
@@ -120,6 +120,11 @@ test: dup() shared fd->off
test: indirect blocks. files and directories.
test: sbrk
test: does echo foo > x truncate x?
+test: does create/mkdir/link extract last component correctly?
+ does namei insist that all the intermediate directories exist?
+test: creat/link/mkdir w/ / in name
+test: try to create dir ents when intermediate dir doesn't exist
+ or is a file, not a dir
make proc[0] runnable
cpu early tss and gdt
diff --git a/defs.h b/defs.h
index cb5175d..1e41dba 100644
--- a/defs.h
+++ b/defs.h
@@ -119,11 +119,12 @@ void iunlock(struct inode *ip);
void idecref(struct inode *ip);
void iincref(struct inode *ip);
void iput(struct inode *ip);
-struct inode * namei(char *path, int, uint *);
+struct inode * namei(char *path, int, uint *, char **, struct inode **);
void stati(struct inode *ip, struct stat *st);
int readi(struct inode *ip, char *xdst, uint off, uint n);
int writei(struct inode *ip, char *addr, uint off, uint n);
struct inode *mknod(char *, short, short, short);
+struct inode * mknod1(struct inode *, char *, short, short, short);
int unlink(char *cp);
void iupdate (struct inode *ip);
int link(char *file1, char *file2);
diff --git a/fs.c b/fs.c
index 5280a4d..a83e937 100644
--- a/fs.c
+++ b/fs.c
@@ -241,12 +241,14 @@ bmap(struct inode *ip, uint bn)
if (x == 0)
panic("bmap 2");
} else {
+ if(ip->addrs[INDIRECT] == 0)
+ panic("bmap 3");
inbp = bread(ip->dev, ip->addrs[INDIRECT]);
a = (uint *) inbp->data;
x = a[bn - NDIRECT];
brelse(inbp);
if (x == 0)
- panic("bmap 3");
+ panic("bmap 4");
}
return x;
}
@@ -431,11 +433,14 @@ writei(struct inode *ip, char *addr, uint off, uint n)
// look up a path name, in one of three modes.
// NAMEI_LOOKUP: return locked target inode.
// NAMEI_CREATE: return locked parent inode.
-// but return 0 if name does exist.
+// return 0 if name does exist.
+// *ret_last points to last path component (i.e. new file name).
+// *ret_ip points to the the name that did exist, if it did.
+// *ret_ip and *ret_last may be zero even if return value is zero.
// 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)
+namei(char *path, int mode, uint *ret_off, char **ret_last, struct inode **ret_ip)
{
struct inode *dp;
struct proc *p = curproc[cpu()];
@@ -445,7 +450,18 @@ namei(char *path, int mode, uint *ret_off)
struct dirent *ep;
int i, atend;
unsigned ninum;
-
+
+ if(mode == NAMEI_DELETE && ret_off == 0)
+ panic("namei no ret_off");
+ if(mode == NAMEI_CREATE && ret_last == 0)
+ panic("namei no ret_last");
+ if(ret_off)
+ *ret_off = 0xffffffff;
+ if(ret_last)
+ *ret_last = 0;
+ if(ret_ip)
+ *ret_ip = 0;
+
if (*cp == '/') dp = iget(rootdev, 1);
else {
dp = p->cwd;
@@ -460,6 +476,10 @@ namei(char *path, int mode, uint *ret_off)
if(*cp == '\0'){
if(mode == NAMEI_LOOKUP)
return dp;
+ if(mode == NAMEI_CREATE && ret_ip){
+ *ret_ip = dp;
+ return 0;
+ }
iput(dp);
return 0;
}
@@ -493,8 +513,14 @@ namei(char *path, int mode, uint *ret_off)
for(cp1 = cp; *cp1; cp1++)
if(*cp1 == '/')
atend = 0;
- if(mode == NAMEI_CREATE && atend)
+ if(mode == NAMEI_CREATE && atend){
+ if(*cp == '\0'){
+ iput(dp);
+ return 0;
+ }
+ *ret_last = cp;
return dp;
+ }
iput(dp);
return 0;
@@ -521,6 +547,9 @@ wdir(struct inode *dp, char *name, uint ino)
struct dirent de;
int i;
+ if(name[0] == '\0')
+ panic("wdir no name");
+
for(off = 0; off < dp->size; off += sizeof(de)){
if(readi(dp, (char *) &de, off, sizeof(de)) != sizeof(de))
panic("wdir read");
@@ -529,8 +558,11 @@ wdir(struct inode *dp, char *name, uint ino)
}
de.inum = ino;
- for(i = 0; i < DIRSIZ && name[i]; i++)
+ for(i = 0; i < DIRSIZ && name[i]; i++){
+ if(name[i] == '/')
+ panic("wdir /");
de.name[i] = name[i];
+ }
for( ; i < DIRSIZ; i++)
de.name[i] = '\0';
@@ -542,10 +574,23 @@ struct inode *
mknod(char *cp, short type, short major, short minor)
{
struct inode *ip, *dp;
+ char *last;
- if ((dp = namei(cp, NAMEI_CREATE, 0)) == 0)
+ if ((dp = namei(cp, NAMEI_CREATE, 0, &last, 0)) == 0)
return 0;
+ ip = mknod1(dp, last, type, major, minor);
+
+ iput(dp);
+
+ return ip;
+}
+
+struct inode *
+mknod1(struct inode *dp, char *name, short type, short major, short minor)
+{
+ struct inode *ip;
+
ip = ialloc(dp->dev, type);
if (ip == 0) {
iput(dp);
@@ -558,8 +603,8 @@ mknod(char *cp, short type, short major, short minor)
iupdate (ip); // write new inode to disk
- wdir(dp, cp, ip->inum);
- iput(dp);
+ wdir(dp, name, ip->inum);
+
return ip;
}
@@ -570,7 +615,8 @@ unlink(char *cp)
struct dirent de;
uint off, inum, dev;
- if ((dp = namei(cp, NAMEI_DELETE, &off)) == 0)
+ dp = namei(cp, NAMEI_DELETE, &off, 0, 0);
+ if(dp == 0)
return -1;
dev = dp->dev;
@@ -604,8 +650,9 @@ int
link(char *name1, char *name2)
{
struct inode *ip, *dp;
+ char *last;
- if ((ip = namei(name1, NAMEI_LOOKUP, 0)) == 0)
+ if ((ip = namei(name1, NAMEI_LOOKUP, 0, 0, 0)) == 0)
return -1;
if(ip->type == T_DIR){
iput(ip);
@@ -614,7 +661,7 @@ link(char *name1, char *name2)
iunlock(ip);
- if ((dp = namei(name2, NAMEI_CREATE, 0)) == 0) {
+ if ((dp = namei(name2, NAMEI_CREATE, 0, &last, 0)) == 0) {
idecref(ip);
return -1;
}
@@ -628,7 +675,7 @@ link(char *name1, char *name2)
ip->nlink += 1;
iupdate (ip);
- wdir(dp, name2, ip->inum);
+ wdir(dp, last, ip->inum);
iput(dp);
iput(ip);
diff --git a/fs.h b/fs.h
index de81e81..04e0b67 100644
--- a/fs.h
+++ b/fs.h
@@ -9,7 +9,7 @@ struct superblock{
uint ninodes;
};
-#define NADDRS NDIRECT+1
+#define NADDRS (NDIRECT+1)
#define NDIRECT 12
#define INDIRECT 12
#define NINDIRECT (BSIZE / sizeof(uint))
diff --git a/fstests.c b/fstests.c
index d177ce9..5718402 100644
--- a/fstests.c
+++ b/fstests.c
@@ -213,7 +213,7 @@ unlinkread()
exit();
}
- fd1 = open("xxx", O_CREATE | O_RDWR);
+ fd1 = open("unlinkread", O_CREATE | O_RDWR);
write(fd1, "yyy", 3);
close(fd1);
@@ -230,7 +230,7 @@ unlinkread()
exit();
}
close(fd);
- unlink("xxx");
+ unlink("unlinkread");
puts("unlinkread ok\n");
}
@@ -319,7 +319,7 @@ concreate()
} else {
fd = open(file, O_CREATE | O_RDWR);
if(fd < 0){
- puts("concreate create failed\n");
+ printf(1, "concreate create %s failed\n", file);
exit();
}
close(fd);
@@ -409,12 +409,126 @@ bigdir()
puts("bigdir ok\n");
}
+void
+subdir()
+{
+ int fd;
+
+ if(mkdir("dd") != 0){
+ puts("subdir mkdir dd failed\n");
+ exit();
+ }
+
+ fd = open("dd/ff", O_CREATE | O_RDWR);
+ if(fd < 0){
+ puts("create dd/ff failed\n");
+ exit();
+ }
+ write(fd, "ff", 2);
+ close(fd);
+
+ if(mkdir("/dd/dd") != 0){
+ puts("subdir mkdir dd/dd failed\n");
+ exit();
+ }
+
+ fd = open("dd/dd/ff", O_CREATE | O_RDWR);
+ if(fd < 0){
+ puts("create dd/dd/ff failed\n");
+ exit();
+ }
+ write(fd, "FF", 2);
+ close(fd);
+
+ if(link("dd/dd/ff", "dd/dd/ffff") != 0){
+ puts("link dd/dd/ff dd/dd/ffff failed\n");
+ exit();
+ }
+
+ if(unlink("dd/dd/ff") != 0){
+ puts("unlink dd/dd/ff failed\n");
+ exit();
+ }
+
+ fd = open("dd/dd/ffff", 0);
+ if(fd < 0){
+ puts("open dd/dd/ffff failed\n");
+ exit();
+ }
+ if(read(fd, buf, sizeof(buf)) != 2){
+ puts("read dd/dd/ffff wrong len\n");
+ exit();
+ }
+ close(fd);
+
+ if(open("dd/dd/ff", 0) >= 0){
+ puts("open dd/dd/ff succeeded!\n");
+ exit();
+ }
+
+ if(open("dd/ff/ff", O_CREATE|O_RDWR) >= 0){
+ puts("create dd/ff/ff succeeded!\n");
+ exit();
+ }
+ if(open("dd/xx/ff", O_CREATE|O_RDWR) >= 0){
+ puts("create dd/xx/ff succeeded!\n");
+ exit();
+ }
+ if(link("dd/ff/ff", "dd/dd/xx") == 0){
+ puts("link dd/ff/ff dd/dd/xx succeeded!\n");
+ exit();
+ }
+ if(link("dd/xx/ff", "dd/dd/xx") == 0){
+ puts("link dd/xx/ff dd/dd/xx succeeded!\n");
+ exit();
+ }
+ if(link("dd/ff", "dd/dd/ff") == 0){
+ puts("link dd/ff dd/dd/ff succeeded!\n");
+ exit();
+ }
+ if(mkdir("dd/ff/ff") == 0){
+ puts("mkdir dd/ff/ff succeeded!\n");
+ exit();
+ }
+ if(mkdir("dd/xx/ff") == 0){
+ puts("mkdir dd/xx/ff succeeded!\n");
+ exit();
+ }
+ if(mkdir("dd/dd/ff") == 0){
+ puts("mkdir dd/dd/ff succeeded!\n");
+ exit();
+ }
+ if(unlink("dd/xx/ff") == 0){
+ puts("unlink dd/xx/ff succeeded!\n");
+ exit();
+ }
+ if(unlink("dd/ff/ff") == 0){
+ puts("unlink dd/ff/ff succeeded!\n");
+ exit();
+ }
+
+ if(unlink("dd/dd/ff") != 0){
+ puts("unlink dd/dd/ff failed\n");
+ exit();
+ }
+ if(unlink("dd/ff") != 0){
+ puts("unlink dd/ff failed\n");
+ exit();
+ }
+
+ // unlink dd/dd
+ // unlink dd
+
+ puts("subdir ok\n");
+}
+
int
main(int argc, char *argv[])
{
puts("fstests starting\n");
- bigdir();
+ subdir();
+ // bigdir(); // slow
concreate();
linktest();
unlinkread();
diff --git a/fsvar.h b/fsvar.h
index 6f4e68a..ec8d204 100644
--- a/fsvar.h
+++ b/fsvar.h
@@ -10,7 +10,7 @@ struct inode {
short minor;
short nlink;
uint size;
- uint addrs[NDIRECT];
+ uint addrs[NADDRS];
};
extern uint rootdev;
diff --git a/syscall.c b/syscall.c
index 39cd107..8571cca 100644
--- a/syscall.c
+++ b/syscall.c
@@ -219,24 +219,34 @@ int
sys_open(void)
{
struct proc *cp = curproc[cpu()];
- struct inode *ip;
+ struct inode *ip, *dp;
uint arg0, arg1;
int ufd;
struct fd *fd;
int l;
+ char *last;
if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0)
return -1;
if((l = checkstring(arg0)) < 0)
return -1;
- if((ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0)) == 0) {
- if (arg1 & O_CREATE) {
- if (l >= DIRSIZ)
- return -1;
- ip = mknod (cp->mem + arg0, T_FILE, 0, 0);
- if (ip == 0) return -1;
- } else return -1;
+
+ if(arg1 & O_CREATE){
+ dp = namei(cp->mem + arg0, 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){
+ return -1;
+ }
+ } else {
+ ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0);
+ if(ip == 0)
+ return -1;
}
+
if((fd = fd_alloc()) == 0){
iput(ip);
return -1;
@@ -316,7 +326,7 @@ sys_mkdir(void)
de.inum = nip->inum;
writei (nip, (char *) &de, 0, sizeof(de));
- pip = namei(".", NAMEI_LOOKUP, 0);
+ pip = namei(".", NAMEI_LOOKUP, 0, 0, 0);
de.inum = pip->inum;
de.name[1] = '.';
iput(pip);
@@ -344,7 +354,7 @@ sys_chdir(void)
if(l >= DIRSIZ)
return -1;
- if ((ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0)) == 0)
+ if ((ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0)) == 0)
return -1;
if (ip == cp->cwd) {
@@ -475,7 +485,7 @@ sys_exec(void)
return -1;
if(checkstring(arg0) < 0)
return -1;
- ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0);
+ ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0);
if(ip == 0)
return -1;