| 0,0 → 1,140 |
|---|
| /* This file contains the code for performing four system calls relating to |
| * status and directories. |
| */ |
| |
| /* Methods: |
| * do_chdir: perform the CHDIR system call |
| * do_stat: perform the STAT system call |
| * do_fstat: perform the FSTAT system call |
| */ |
| |
| |
| #include "fs.h" |
| #include "stat.h" |
| #include "file.h" |
| #include "fproc.h" |
| #include "inode.h" |
| #include "param.h" |
| |
| |
| static int change(inode_t **iip, char *name_ptr, int len); |
| static int stat_inode(inode_t *rip, filp_t *fil_ptr, char *user_addr); |
| |
| int do_chdir() |
| { |
| |
| /* Perform the chdir(file_name) system call */ |
| int r; |
| |
| r = change(&fp->fp_workdir, file_name, strlen(file_name)+1); |
| |
| return r; |
| } |
| |
| int change(inode_t **iip, char *name_ptr, int len) |
| { |
| |
| /* |
| * iip: pointer to the inode pointer for the dir |
| * name_ptr: pointer to the directory name to change to |
| * len: length of the directory name string |
| */ |
| |
| /* Do the actual work for chdir() and chroot(). */ |
| |
| inode_t *rip; |
| register int r; |
| |
| r = OK; |
| |
| /* Try to open the new directory. */ |
| if (fetch_name(name_ptr, len) != OK) |
| return err_code; |
| |
| if ((rip = eat_path(user_path)) == NIL_INODE) |
| return err_code; |
| |
| /* It must be a directory and also be searchable. */ |
| if ((rip->i_mode & I_TYPE) != I_DIRECTORY) |
| r = FS_ENOTDIR; |
| |
| /* If error, return inode. */ |
| if (r != OK) { |
| put_inode(rip); |
| return r; |
| } |
| |
| /* Everything is OK. Make the change. */ |
| put_inode(*iip); /* release the old directory */ |
| *iip = rip; /* acquire the new one */ |
| |
| return OK; |
| } |
| |
| int do_stat() |
| { |
| |
| /* Perform the stat(name, buf) system call. */ |
| |
| register inode_t *rip; |
| register int r; |
| |
| /* Both stat() and fstat() use the same routine to do the real work. That |
| * routine expects an inode, so acquire it temporarily. |
| */ |
| |
| if (fetch_name(file_name, strlen(file_name)+1) != OK) |
| return err_code; |
| |
| if ((rip = eat_path(user_path)) == NIL_INODE) |
| return err_code; |
| |
| r = stat_inode(rip, NIL_FILP, fp->buffer); /* actually do the work.*/ |
| put_inode(rip); /* release the inode */ |
| |
| return r; |
| } |
| |
| int do_fstat() |
| { |
| |
| /* Perform the fstat(fd, buf) system call. */ |
| |
| register filp_t *rfilp; |
| |
| |
| /* Is the file descriptor valid? */ |
| if ((rfilp = get_filp(fd)) == NIL_FILP) |
| return err_code; |
| |
| if (rfilp->filp_ino == NIL_INODE) |
| return FS_ENOENT; |
| |
| return(stat_inode(rfilp->filp_ino, NIL_FILP, fp->buffer)); |
| } |
| |
| int stat_inode(register inode_t *rip, filp_t *fil_ptr, char *user_addr) |
| { |
| |
| /* |
| * rip: pointer to inode to stat |
| * fil_ptr: filp pointer, supplied by 'fstat' |
| * user_addr: user space address where stat buf goes |
| */ |
| |
| /* Common code for stat and fstat system calls. */ |
| |
| stat_t statbuf; |
| |
| /* Fill in the statbuf struct. */ |
| statbuf.st_ino = rip->i_num; |
| statbuf.st_mode = rip->i_mode; |
| statbuf.st_nlink = rip->i_nlinks & BYTE; |
| statbuf.st_size = rip->i_size; |
| |
| /* Copy infomations to userspace. */ |
| memcpy(user_addr, &statbuf, sizeof(statbuf)); |
| |
| return OK; |
| } |
| |