symlink.patch (3783B)
1 diff -r f8a4e40ab1d6 fs.c 2 --- a/fs.c Thu Aug 30 14:32:06 2007 -0400 3 +++ b/fs.c Thu Aug 30 14:29:02 2007 -0400 4 @@ -577,12 +577,18 @@ skipelem(char *path, char *name) 5 // If parent != 0, return the inode for the parent and copy the final 6 // path element into name, which must have room for DIRSIZ bytes. 7 static struct inode* 8 -_namei(char *path, int parent, char *name) 9 +_namei(struct inode *root, char *path, int parent, char *name, int depth) 10 { 11 struct inode *ip, *next; 12 + char buf[100], tname[DIRSIZ]; 13 + 14 + if(depth > 5) 15 + return 0; 16 17 if(*path == '/') 18 ip = iget(ROOTDEV, 1); 19 + else if(root) 20 + ip = idup(root); 21 else 22 ip = idup(cp->cwd); 23 24 @@ -598,10 +604,24 @@ _namei(char *path, int parent, char *nam 25 return ip; 26 } 27 if((next = dirlookup(ip, name, 0)) == 0){ 28 + cprintf("did not find %s\n", name); 29 iunlockput(ip); 30 return 0; 31 } 32 - iunlockput(ip); 33 + iunlock(ip); 34 + ilock(next); 35 + if(next->type == T_SYMLINK){ 36 + if(next->size >= sizeof(buf) || readi(next, buf, 0, next->size) != next->size){ 37 + iunlockput(next); 38 + iput(ip); 39 + return 0; 40 + } 41 + buf[next->size] = 0; 42 + iunlockput(next); 43 + next = _namei(ip, buf, 0, tname, depth+1); 44 + }else 45 + iunlock(next); 46 + iput(ip); 47 ip = next; 48 } 49 if(parent){ 50 @@ -615,11 +635,11 @@ namei(char *path) 51 namei(char *path) 52 { 53 char name[DIRSIZ]; 54 - return _namei(path, 0, name); 55 + return _namei(0, path, 0, name, 0); 56 } 57 58 struct inode* 59 nameiparent(char *path, char *name) 60 { 61 - return _namei(path, 1, name); 62 -} 63 + return _namei(0, path, 1, name, 0); 64 +} 65 diff -r f8a4e40ab1d6 fs.h 66 --- a/fs.h Thu Aug 30 14:32:06 2007 -0400 67 +++ b/fs.h Thu Aug 30 13:05:43 2007 -0400 68 @@ -33,6 +33,7 @@ struct dinode { 69 #define T_DIR 1 // Directory 70 #define T_FILE 2 // File 71 #define T_DEV 3 // Special device 72 +#define T_SYMLINK 4 // Symlink 73 74 // Inodes per block. 75 #define IPB (BSIZE / sizeof(struct dinode)) 76 diff -r f8a4e40ab1d6 syscall.c 77 --- a/syscall.c Thu Aug 30 14:32:06 2007 -0400 78 +++ b/syscall.c Thu Aug 30 13:05:29 2007 -0400 79 @@ -96,6 +96,7 @@ extern int sys_unlink(void); 80 extern int sys_unlink(void); 81 extern int sys_wait(void); 82 extern int sys_write(void); 83 +extern int sys_symlink(void); 84 85 static int (*syscalls[])(void) = { 86 [SYS_chdir] sys_chdir, 87 @@ -118,6 +119,7 @@ static int (*syscalls[])(void) = { 88 [SYS_unlink] sys_unlink, 89 [SYS_wait] sys_wait, 90 [SYS_write] sys_write, 91 +[SYS_symlink] sys_symlink, 92 }; 93 94 void 95 diff -r f8a4e40ab1d6 syscall.h 96 --- a/syscall.h Thu Aug 30 14:32:06 2007 -0400 97 +++ b/syscall.h Thu Aug 30 13:02:48 2007 -0400 98 @@ -19,3 +19,4 @@ 99 #define SYS_getpid 18 100 #define SYS_sbrk 19 101 #define SYS_sleep 20 102 +#define SYS_symlink 21 103 diff -r f8a4e40ab1d6 sysfile.c 104 --- a/sysfile.c Thu Aug 30 14:32:06 2007 -0400 105 +++ b/sysfile.c Thu Aug 30 13:10:31 2007 -0400 106 @@ -257,6 +257,21 @@ create(char *path, int canexist, short t 107 } 108 109 int 110 +sys_symlink(void) 111 +{ 112 + char *old, *new; 113 + struct inode *ip; 114 + 115 + if(argstr(0, &old) < 0 || argstr(1, &new) < 0) 116 + return -1; 117 + if((ip = create(new, 0, T_SYMLINK, 0, 0)) == 0) 118 + return -1; 119 + writei(ip, old, 0, strlen(old)); 120 + iunlockput(ip); 121 + return 0; 122 +} 123 + 124 +int 125 sys_open(void) 126 { 127 char *path; 128 @@ -393,3 +408,4 @@ sys_pipe(void) 129 fd[1] = fd1; 130 return 0; 131 } 132 + 133 diff -r f8a4e40ab1d6 user.h 134 --- a/user.h Thu Aug 30 14:32:06 2007 -0400 135 +++ b/user.h Thu Aug 30 13:02:34 2007 -0400 136 @@ -21,6 +21,7 @@ int getpid(); 137 int getpid(); 138 char* sbrk(int); 139 int sleep(int); 140 +int symlink(int); 141 142 // ulib.c 143 int stat(char*, struct stat*); 144 diff -r f8a4e40ab1d6 usys.S 145 --- a/usys.S Thu Aug 30 14:32:06 2007 -0400 146 +++ b/usys.S Thu Aug 30 13:05:54 2007 -0400 147 @@ -28,3 +28,4 @@ STUB(getpid) 148 STUB(getpid) 149 STUB(sbrk) 150 STUB(sleep) 151 +STUB(symlink)