URL https://opencores.org/ocsvn/or1k_old/or1k_old/trunk
Subversion Repositories or1k_old

[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [namei.c] - Blame information for rev 1782

Details | Compare with Previous | View Log

/*
 *  linux/fs/namei.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */
 
/*
 * Some corrections by tytso.
 *
 * Aug 97 - cevans - fix security problem with O_TRUNC and append only files
 */
 
/*
 * uClinux revisions for NO_MM
 * Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
 *                     The Silver Hammer Group, Ltd.
 */
 
#include <asm/segment.h>
 
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/mm.h>
 
#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
 
/*
 * How long a filename can we get from user space?
 *  -EFAULT if invalid area
 *  0 if ok (ENAMETOOLONG before EFAULT)
 *  >0 EFAULT after xx bytes
 */
static inline int get_max_filename(unsigned long address)
{
#ifndef NO_MM
        struct vm_area_struct * vma;
#endif /* !NO_MM */
 
        if (get_fs() == KERNEL_DS)
                return 0;
#ifndef NO_MM
        vma = find_vma(current->mm, address);
        if (!vma || vma->vm_start > address || !(vma->vm_flags & VM_READ))
                return -EFAULT;
        address = vma->vm_end - address;
        if (address > PAGE_SIZE)
                return 0;
        if (vma->vm_next && vma->vm_next->vm_start == vma->vm_end &&
           (vma->vm_next->vm_flags & VM_READ))
                return 0;
        return address;
#endif /* !NO_MM */
        return PAGE_SIZE;
}
 
/*
 * In order to reduce some races, while at the same time doing additional
 * checking and hopefully speeding things up, we copy filenames to the
 * kernel data space before using them..
 *
 * POSIX.1 2.4: an empty pathname is invalid (ENOENT).
 */
int getname(const char * filename, char **result)
{
        int i, error;
        unsigned long page;
        char * tmp, c;
 
        i = get_max_filename((unsigned long) filename);
        if (i < 0)
                return i;
        error = -EFAULT;
        if (!i) {
                error = -ENAMETOOLONG;
                i = PAGE_SIZE;
        }
        c = get_user(filename++);
        if (!c)
                return -ENOENT;
        if(!(page = __get_free_page(GFP_KERNEL)))
                return -ENOMEM;
        *result = tmp = (char *) page;
        while (--i) {
                *(tmp++) = c;
                c = get_user(filename++);
                if (!c) {
                        *tmp = '\0';
                        return 0;
                }
        }
        free_page(page);
        return error;
}
 
void putname(char * name)
{
        free_page((unsigned long) name);
}
 
/*
 *      permission()
 *
 * is used to check for read/write/execute permissions on a file.
 * We use "fsuid" for this, letting us set arbitrary permissions
 * for filesystem access without changing the "normal" uids which
 * are used for other things..
 */
int permission(struct inode * inode,int mask)
{
        int mode = inode->i_mode;
 
        if (inode->i_op && inode->i_op->permission)
                return inode->i_op->permission(inode, mask);
        else if ((mask & S_IWOTH) && IS_RDONLY(inode) &&
                 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
                return -EROFS; /* Nobody gets write access to a read-only fs */
        else if ((mask & S_IWOTH) && IS_IMMUTABLE(inode)) {
                return -EACCES; /* Nobody gets write access to an immutable file */
        }
        else if (current->fsuid == inode->i_uid)
                mode >>= 6;
        else if (in_group_p(inode->i_gid))
                mode >>= 3;
        if (((mode & mask & 0007) == mask) || fsuser())
                return 0;
        return -EACCES;
}
 
/*
 * get_write_access() gets write permission for a file.
 * put_write_access() releases this write permission.
 * This is used for regular files.
 * We cannot support write (and maybe mmap read-write shared) accesses and
 * MAP_DENYWRITE mmappings simultaneously.
 */
int get_write_access(struct inode * inode)
{
#ifndef NO_MM
        struct task_struct * p;
 
        if ((inode->i_count > 1) && S_ISREG(inode->i_mode)) /* shortcut */
                for_each_task(p) {
                        struct vm_area_struct * mpnt;
                        if (!p->mm)
                                continue;
                        for(mpnt = p->mm->mmap; mpnt; mpnt = mpnt->vm_next) {
                                if (inode != mpnt->vm_inode)
                                        continue;
                                if (mpnt->vm_flags & VM_DENYWRITE)
                                        return -ETXTBSY;
                        }
                }
#endif /* !NO_MM */
        inode->i_writecount++;
        return 0;
}
 
void put_write_access(struct inode * inode)
{
        inode->i_writecount--;
}
 
/*
 * lookup() looks up one part of a pathname, using the fs-dependent
 * routines (currently minix_lookup) for it. It also checks for
 * fathers (pseudo-roots, mount-points)
 */
int lookup(struct inode * dir,const char * name, int len,
           struct inode ** result)
{
        struct super_block * sb;
        int perm;
 
        *result = NULL;
        if (!dir)
                return -ENOENT;
/* check permissions before traversing mount-points */
        perm = permission(dir,MAY_EXEC);
        if (len==2 && name[0] == '.' && name[1] == '.') {
                if (dir == current->fs->root) {
                        *result = dir;
                        return 0;
                } else if ((sb = dir->i_sb) && (dir == sb->s_mounted)) {
                        iput(dir);
                        dir = sb->s_covered;
                        if (!dir)
                                return -ENOENT;
                        dir->i_count++;
                }
        }
        if (!dir->i_op || !dir->i_op->lookup) {
                iput(dir);
                return -ENOTDIR;
        }
        if (perm != 0) {
                iput(dir);
                return perm;
        }
        if (!len) {
                *result = dir;
                return 0;
        }
        return dir->i_op->lookup(dir, name, len, result);
}
 
int follow_link(struct inode * dir, struct inode * inode,
        int flag, int mode, struct inode ** res_inode)
{
        if (!dir || !inode) {
                iput(dir);
                iput(inode);
                *res_inode = NULL;
                return -ENOENT;
        }
        if (!inode->i_op || !inode->i_op->follow_link) {
                iput(dir);
                *res_inode = inode;
                return 0;
        }
        return inode->i_op->follow_link(dir,inode,flag,mode,res_inode);
}
 
/*
 *      dir_namei()
 *
 * dir_namei() returns the inode of the directory of the
 * specified name, and the name within that directory.
 */
static int dir_namei(const char *pathname, int *namelen, const char **name,
                     struct inode * base, struct inode **res_inode)
{
        char c;
        const char * thisname;
        int len,error;
        struct inode * inode;
 
        *res_inode = NULL;
        if (!base) {
                base = current->fs->pwd;
                base->i_count++;
        }
        if ((c = *pathname) == '/') {
                iput(base);
                base = current->fs->root;
                pathname++;
                base->i_count++;
        }
        while (1) {
                thisname = pathname;
                for(len=0;(c = *(pathname++))&&(c != '/');len++)
                        /* nothing */ ;
                if (!c)
                        break;
                base->i_count++;
                error = lookup(base, thisname, len, &inode);
                if (error) {
                        iput(base);
                        return error;
                }
                error = follow_link(base,inode,0,0,&base);
                if (error)
                        return error;
        }
        if (!base->i_op || !base->i_op->lookup) {
                iput(base);
                return -ENOTDIR;
        }
        *name = thisname;
        *namelen = len;
        *res_inode = base;
        return 0;
}
 
static int _namei(const char * pathname, struct inode * base,
                  int follow_links, struct inode ** res_inode)
{
        const char *basename;
        int namelen,error;
        struct inode * inode;
 
        *res_inode = NULL;
        error = dir_namei(pathname, &namelen, &basename, base, &base);
        if (error)
                return error;
        base->i_count++;        /* lookup uses up base */
        error = lookup(base, basename, namelen, &inode);
        if (error) {
                iput(base);
                return error;
        }
        if (follow_links) {
                error = follow_link(base, inode, 0, 0, &inode);
                if (error)
                        return error;
        } else
                iput(base);
        if ((inode->i_flags & S_BAD_INODE) != 0) {
                iput(inode);
                return -EIO;
        }
        *res_inode = inode;
        return 0;
}
 
int lnamei(const char *pathname, struct inode **res_inode)
{
        int error;
        char * tmp;
 
        error = getname(pathname, &tmp);
        if (!error) {
                error = _namei(tmp, NULL, 0, res_inode);
                putname(tmp);
        }
        return error;
}
 
/*
 *      namei()
 *
 * is used by most simple commands to get the inode of a specified name.
 * Open, link etc use their own routines, but this is enough for things
 * like 'chmod' etc.
 */
int namei(const char *pathname, struct inode **res_inode)
{
        int error;
        char * tmp;
 
        error = getname(pathname, &tmp);
        if (!error) {
                error = _namei(tmp, NULL, 1, res_inode);
                putname(tmp);
        }
        return error;
}
 
/*
 *      open_namei()
 *
 * namei for open - this is in fact almost the whole open-routine.
 *
 * Note that the low bits of "flag" aren't the same as in the open
 * system call - they are 00 - no permissions needed
 *                        01 - read permission needed
 *                        10 - write permission needed
 *                        11 - read/write permissions needed
 * which is a lot more logical, and also allows the "no perm" needed
 * for symlinks (where the permissions are checked later).
 */
int open_namei(const char * pathname, int flag, int mode,
               struct inode ** res_inode, struct inode * base)
{
        const char * basename;
        int namelen,error;
        struct inode * dir, *inode;
 
        mode &= S_IALLUGO & ~current->fs->umask;
        mode |= S_IFREG;
        error = dir_namei(pathname, &namelen, &basename, base, &dir);
        if (error)
                return error;
        if (!namelen) {                 /* special case: '/usr/' etc */
                if (flag & 2) {
                        iput(dir);
                        return -EISDIR;
                }
                /* thanks to Paul Pluzhnikov for noticing this was missing.. */
                if ((error = permission(dir,ACC_MODE(flag))) != 0) {
                        iput(dir);
                        return error;
                }
                *res_inode=dir;
                return 0;
        }
        dir->i_count++;         /* lookup eats the dir */
        if (flag & O_CREAT) {
                down(&dir->i_sem);
                error = lookup(dir, basename, namelen, &inode);
                if (!error) {
                        if (flag & O_EXCL) {
                                iput(inode);
                                error = -EEXIST;
                        }
                } else if (IS_RDONLY(dir)) {
                        error = -EROFS;
                }
                else if (!dir->i_op || !dir->i_op->create) {
                        error = -EACCES;
                }
                else if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0)
                        ;       /* error is already set! */
                else {
                        dir->i_count++;         /* create eats the dir */
                        if (dir->i_sb && dir->i_sb->dq_op)
                                dir->i_sb->dq_op->initialize(dir, -1);
                        error = dir->i_op->create(dir, basename, namelen, mode, res_inode);
                        up(&dir->i_sem);
                        iput(dir);
                        return error;
                }
                up(&dir->i_sem);
        } else
                error = lookup(dir, basename, namelen, &inode);
        if (error) {
                iput(dir);
                return error;
        }
        error = follow_link(dir,inode,flag,mode,&inode);
        if (error) {
                return error;
        }
        if (S_ISDIR(inode->i_mode) && (flag & 2)) {
                iput(inode);
                return -EISDIR;
        }
        if ((error = permission(inode,ACC_MODE(flag))) != 0) {
                iput(inode);
                return error;
        }
        if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
                /*
                 * 2-Feb-1995 Bruce Perens <Bruce@Pixar.com>
                 * Allow opens of Unix domain sockets and FIFOs for write on
                 * read-only filesystems. Their data does not live on the disk.
                 *
                 * If there was something like IS_NODEV(inode) for
                 * pipes and/or sockets I'd check it here.
                 */
                flag &= ~O_TRUNC;
        }
        else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
                if (IS_NODEV(inode)) {
                        iput(inode);
                        return -EACCES;
                }
                flag &= ~O_TRUNC;
        } else {
                if (IS_RDONLY(inode) && (flag & 2)) {
                        iput(inode);
                        return -EROFS;
                }
        }
        /*
         * An append-only file must be opened in append mode for writing
         * Additionally, we must disallow O_TRUNC -- cevans
         */
        if (IS_APPEND(inode) && (((flag & FMODE_WRITE) && !(flag & O_APPEND)) || (flag & O_TRUNC))) {
                iput(inode);
                return -EPERM;
        }
        if (flag & O_TRUNC) {
                if ((error = get_write_access(inode))) {
                        iput(inode);
                        return error;
                }
                /*
                 * Refuse to truncate files with mandatory locks held on them
                 */
                error = locks_verify_locked(inode);
                if (error) {
                        iput(inode);
                        return error;
                }
                if (inode->i_sb && inode->i_sb->dq_op)
                        inode->i_sb->dq_op->initialize(inode, -1);
 
                error = do_truncate(inode, 0);
                put_write_access(inode);
                if (error) {
                        iput(inode);
                        return error;
                }
        } else
                if (flag & FMODE_WRITE)
                        if (inode->i_sb && inode->i_sb->dq_op)
                                inode->i_sb->dq_op->initialize(inode, -1);
        *res_inode = inode;
        return 0;
}
 
int do_mknod(const char * filename, int mode, dev_t dev)
{
        const char * basename;
        int namelen, error;
        struct inode * dir;
 
        mode &= ~current->fs->umask;
        error = dir_namei(filename, &namelen, &basename, NULL, &dir);
        if (error)
                return error;
        if (!namelen) {
                iput(dir);
                return -ENOENT;
        }
        if (IS_RDONLY(dir)) {
                iput(dir);
                return -EROFS;
        }
        if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(dir);
                return error;
        }
        if (!dir->i_op || !dir->i_op->mknod) {
                iput(dir);
                return -EPERM;
        }
        dir->i_count++;
        if (dir->i_sb && dir->i_sb->dq_op)
                dir->i_sb->dq_op->initialize(dir, -1);
        down(&dir->i_sem);
        error = dir->i_op->mknod(dir,basename,namelen,mode,dev);
        up(&dir->i_sem);
        iput(dir);
        return error;
}
 
asmlinkage int sys_mknod(const char * filename, int mode, dev_t dev)
{
        int error;
        char * tmp;
 
        if (S_ISDIR(mode) || (!S_ISFIFO(mode) && !fsuser()))
                return -EPERM;
        switch (mode & S_IFMT) {
        case 0:
                mode |= S_IFREG;
                break;
        case S_IFREG: case S_IFCHR: case S_IFBLK: case S_IFIFO: case S_IFSOCK:
                break;
        default:
                return -EINVAL;
        }
        error = getname(filename,&tmp);
        if (!error) {
                error = do_mknod(tmp,mode,dev);
                putname(tmp);
        }
        return error;
}
 
/*
 * Some operations need to remove trailing slashes for POSIX.1
 * conformance. For rename we also need to change the behaviour
 * depending on whether we had a trailing slash or not.. (we
 * cannot rename normal files with trailing slashes, only dirs)
 *
 * "dummy" is used to make sure we don't do "/" -> "".
 */
static int remove_trailing_slashes(char * name)
{
        int result;
        char dummy[1];
        char *remove = dummy+1;
 
        for (;;) {
                char c = *name;
                name++;
                if (!c)
                        break;
                if (c != '/') {
                        remove = NULL;
                        continue;
                }
                if (remove)
                        continue;
                remove = name;
        }
 
        result = 0;
        if (remove) {
                remove[-1] = 0;
                result = 1;
        }
 
        return result;
}
 
static int do_mkdir(const char * pathname, int mode)
{
        const char * basename;
        int namelen, error;
        struct inode * dir;
 
        error = dir_namei(pathname, &namelen, &basename, NULL, &dir);
        if (error)
                return error;
        if (!namelen) {
                iput(dir);
                return -ENOENT;
        }
        if (IS_RDONLY(dir)) {
                iput(dir);
                return -EROFS;
        }
        if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(dir);
                return error;
        }
        if (!dir->i_op || !dir->i_op->mkdir) {
                iput(dir);
                return -EPERM;
        }
        dir->i_count++;
        if (dir->i_sb && dir->i_sb->dq_op)
                dir->i_sb->dq_op->initialize(dir, -1);
        down(&dir->i_sem);
        error = dir->i_op->mkdir(dir, basename, namelen, mode & 01777 & ~current->fs->umask);
        up(&dir->i_sem);
        iput(dir);
        return error;
}
 
asmlinkage int sys_mkdir(const char * pathname, int mode)
{
        int error;
        char * tmp;
 
        error = getname(pathname,&tmp);
        if (!error) {
                remove_trailing_slashes(tmp);
                error = do_mkdir(tmp,mode);
                putname(tmp);
        }
        return error;
}
 
static int do_rmdir(const char * name)
{
        const char * basename;
        int namelen, error;
        struct inode * dir;
 
        error = dir_namei(name, &namelen, &basename, NULL, &dir);
        if (error)
                return error;
        if (!namelen) {
                iput(dir);
                return -ENOENT;
        }
        if (IS_RDONLY(dir)) {
                iput(dir);
                return -EROFS;
        }
        if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(dir);
                return error;
        }
        /*
         * A subdirectory cannot be removed from an append-only directory
         */
        if (IS_APPEND(dir)) {
                iput(dir);
                return -EPERM;
        }
        if (!dir->i_op || !dir->i_op->rmdir) {
                iput(dir);
                return -EPERM;
        }
        if (dir->i_sb && dir->i_sb->dq_op)
                dir->i_sb->dq_op->initialize(dir, -1);
        down(&dir->i_sem);
        error = dir->i_op->rmdir(dir,basename,namelen);
        up(&dir->i_sem);
        return error;
}
 
asmlinkage int sys_rmdir(const char * pathname)
{
        int error;
        char * tmp;
 
        error = getname(pathname,&tmp);
        if (!error) {
                remove_trailing_slashes(tmp);
                error = do_rmdir(tmp);
                putname(tmp);
        }
        return error;
}
 
static int do_unlink(const char * name)
{
        const char * basename;
        int namelen, error;
        struct inode * dir;
 
        error = dir_namei(name, &namelen, &basename, NULL, &dir);
        if (error)
                return error;
        if (!namelen) {
                iput(dir);
                return -EPERM;
        }
        if (IS_RDONLY(dir)) {
                iput(dir);
                return -EROFS;
        }
        if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(dir);
                return error;
        }
        /*
         * A file cannot be removed from an append-only directory
         */
        if (IS_APPEND(dir)) {
                iput(dir);
                return -EPERM;
        }
        if (!dir->i_op || !dir->i_op->unlink) {
                iput(dir);
                return -EPERM;
        }
        if (dir->i_sb && dir->i_sb->dq_op)
                dir->i_sb->dq_op->initialize(dir, -1);
        down(&dir->i_sem);
        error = dir->i_op->unlink(dir,basename,namelen);
        up(&dir->i_sem);
        return error;
}
 
asmlinkage int sys_unlink(const char * pathname)
{
        int error;
        char * tmp;
 
        error = getname(pathname,&tmp);
        if (!error) {
                error = do_unlink(tmp);
                putname(tmp);
        }
        return error;
}
 
static int do_symlink(const char * oldname, const char * newname)
{
        struct inode * dir;
        const char * basename;
        int namelen, error;
 
        error = dir_namei(newname, &namelen, &basename, NULL, &dir);
        if (error)
                return error;
        if (!namelen) {
                iput(dir);
                return -ENOENT;
        }
        if (IS_RDONLY(dir)) {
                iput(dir);
                return -EROFS;
        }
        if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(dir);
                return error;
        }
        if (!dir->i_op || !dir->i_op->symlink) {
                iput(dir);
                return -EPERM;
        }
        dir->i_count++;
        if (dir->i_sb && dir->i_sb->dq_op)
                dir->i_sb->dq_op->initialize(dir, -1);
        down(&dir->i_sem);
        error = dir->i_op->symlink(dir,basename,namelen,oldname);
        up(&dir->i_sem);
        iput(dir);
        return error;
}
 
asmlinkage int sys_symlink(const char * oldname, const char * newname)
{
        int error;
        char * from, * to;
 
        error = getname(oldname,&from);
        if (!error) {
                error = getname(newname,&to);
                if (!error) {
                        error = do_symlink(from,to);
                        putname(to);
                }
                putname(from);
        }
        return error;
}
 
static int do_link(struct inode * oldinode, const char * newname)
{
        struct inode * dir;
        const char * basename;
        int namelen, error;
 
        error = dir_namei(newname, &namelen, &basename, NULL, &dir);
        if (error) {
                iput(oldinode);
                return error;
        }
        if (!namelen) {
                iput(oldinode);
                iput(dir);
                return -EPERM;
        }
        if (IS_RDONLY(dir)) {
                iput(oldinode);
                iput(dir);
                return -EROFS;
        }
        if (dir->i_dev != oldinode->i_dev) {
                iput(dir);
                iput(oldinode);
                return -EXDEV;
        }
        if ((error = permission(dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(dir);
                iput(oldinode);
                return error;
        }
        /*
         * A link to an append-only or immutable file cannot be created
         */
        if (IS_APPEND(oldinode) || IS_IMMUTABLE(oldinode)) {
                iput(dir);
                iput(oldinode);
                return -EPERM;
        }
        if (!dir->i_op || !dir->i_op->link) {
                iput(dir);
                iput(oldinode);
                return -EPERM;
        }
        dir->i_count++;
        if (dir->i_sb && dir->i_sb->dq_op)
                dir->i_sb->dq_op->initialize(dir, -1);
        down(&dir->i_sem);
        error = dir->i_op->link(oldinode, dir, basename, namelen);
        up(&dir->i_sem);
        iput(dir);
        return error;
}
 
asmlinkage int sys_link(const char * oldname, const char * newname)
{
        int error;
        char * to;
        struct inode * oldinode;
 
        error = lnamei(oldname, &oldinode);
        if (error)
                return error;
        error = getname(newname,&to);
        if (error) {
                iput(oldinode);
                return error;
        }
        error = do_link(oldinode,to);
        putname(to);
        return error;
}
 
static int do_rename(const char * oldname, const char * newname, int must_be_dir)
{
        struct inode * old_dir, * new_dir;
        const char * old_base, * new_base;
        int old_len, new_len, error;
 
        error = dir_namei(oldname, &old_len, &old_base, NULL, &old_dir);
        if (error)
                return error;
        if ((error = permission(old_dir,MAY_WRITE | MAY_EXEC)) != 0) {
                iput(old_dir);
                return error;
        }
        if (!old_len || (old_base[0] == '.' &&
            (old_len == 1 || (old_base[1] == '.' &&
             old_len == 2)))) {
                iput(old_dir);
                return -EPERM;
        }
        error = dir_namei(newname, &new_len, &new_base, NULL, &new_dir);
        if (error) {
                iput(old_dir);
                return error;
        }
        if ((error = permission(new_dir,MAY_WRITE | MAY_EXEC)) != 0){
                iput(old_dir);
                iput(new_dir);
                return error;
        }
        if (!new_len || (new_base[0] == '.' &&
            (new_len == 1 || (new_base[1] == '.' &&
             new_len == 2)))) {
                iput(old_dir);
                iput(new_dir);
                return -EPERM;
        }
        if (new_dir->i_dev != old_dir->i_dev) {
                iput(old_dir);
                iput(new_dir);
                return -EXDEV;
        }
        if (IS_RDONLY(new_dir) || IS_RDONLY(old_dir)) {
                iput(old_dir);
                iput(new_dir);
                return -EROFS;
        }
        /*
         * A file cannot be removed from an append-only directory
         */
        if (IS_APPEND(old_dir)) {
                iput(old_dir);
                iput(new_dir);
                return -EPERM;
        }
        if (!old_dir->i_op || !old_dir->i_op->rename) {
                iput(old_dir);
                iput(new_dir);
                return -EPERM;
        }
        new_dir->i_count++;
        if (new_dir->i_sb && new_dir->i_sb->dq_op)
                new_dir->i_sb->dq_op->initialize(new_dir, -1);
        down(&new_dir->i_sem);
        error = old_dir->i_op->rename(old_dir, old_base, old_len,
                new_dir, new_base, new_len, must_be_dir);
        up(&new_dir->i_sem);
        iput(new_dir);
        return error;
}
 
asmlinkage int sys_rename(const char * oldname, const char * newname)
{
        int error;
        char * from, * to;
 
        error = getname(oldname,&from);
        if (!error) {
                error = getname(newname,&to);
                if (!error) {
                        error = do_rename(from,to,
                                remove_trailing_slashes(from) |
                                remove_trailing_slashes(to));
                        putname(to);
                }
                putname(from);
        }
        return error;
}
Browse

Tools

Subversion Repositories or1k_old

[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [namei.c] - Blame information for rev 1782

Line No.	Rev	Author	Line
1	199	simons	`/*`
2			`* linux/fs/namei.c`
3			`*`
4			`* Copyright (C) 1991, 1992 Linus Torvalds`
5			`*/`
6
7			`/*`
8			`* Some corrections by tytso.`
9			`*`
10			`* Aug 97 - cevans - fix security problem with O_TRUNC and append only files`
11			`*/`
12
13			`/*`
14			`* uClinux revisions for NO_MM`
15			`* Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>,`
16			`* The Silver Hammer Group, Ltd.`
17			`*/`
18
19			`#include <asm/segment.h>`
20
21			`#include <linux/errno.h>`
22			`#include <linux/sched.h>`
23			`#include <linux/kernel.h>`
24			`#include <linux/string.h>`
25			`#include <linux/fcntl.h>`
26			`#include <linux/stat.h>`
27			`#include <linux/mm.h>`
28
29			`#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])`
30
31			`/*`
32			`* How long a filename can we get from user space?`
33			`* -EFAULT if invalid area`
34			`* 0 if ok (ENAMETOOLONG before EFAULT)`
35			`* >0 EFAULT after xx bytes`
36			`*/`
37			`static inline int get_max_filename(unsigned long address)`
38			`{`
39			`#ifndef NO_MM`
40			`struct vm_area_struct * vma;`