1 files changed, 1076 insertions, 0 deletions

diff --git a/fs/open.c b/fs/open.c
new file mode 100644
index 000000000000..963bd81a44c8
--- /dev/null
+++ b/fs/open.c
@@ -0,0 +1,1076 @@
+/*
+ *  linux/fs/open.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/utime.h>
+#include <linux/file.h>
+#include <linux/smp_lock.h>
+#include <linux/quotaops.h>
+#include <linux/dnotify.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/namei.h>
+#include <linux/backing-dev.h>
+#include <linux/security.h>
+#include <linux/mount.h>
+#include <linux/vfs.h>
+#include <asm/uaccess.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/syscalls.h>
+
+#include <asm/unistd.h>
+
+int vfs_statfs(struct super_block *sb, struct kstatfs *buf)
+{
+        int retval = -ENODEV;
+
+        if (sb) {
+                retval = -ENOSYS;
+                if (sb->s_op->statfs) {
+                        memset(buf, 0, sizeof(*buf));
+                        retval = security_sb_statfs(sb);
+                        if (retval)
+                                return retval;
+                        retval = sb->s_op->statfs(sb, buf);
+                        if (retval == 0 && buf->f_frsize == 0)
+                                buf->f_frsize = buf->f_bsize;
+                }
+        }
+        return retval;
+}
+
+EXPORT_SYMBOL(vfs_statfs);
+
+static int vfs_statfs_native(struct super_block *sb, struct statfs *buf)
+{
+        struct kstatfs st;
+        int retval;
+
+        retval = vfs_statfs(sb, &st);
+        if (retval)
+                return retval;
+
+        if (sizeof(*buf) == sizeof(st))
+                memcpy(buf, &st, sizeof(st));
+        else {
+                if (sizeof buf->f_blocks == 4) {
+                        if ((st.f_blocks | st.f_bfree | st.f_bavail) &
+                            0xffffffff00000000ULL)
+                                return -EOVERFLOW;
+                        /*
+                         * f_files and f_ffree may be -1; it's okay to stuff
+                         * that into 32 bits
+                         */
+                        if (st.f_files != -1 &&
+                            (st.f_files & 0xffffffff00000000ULL))
+                                return -EOVERFLOW;
+                        if (st.f_ffree != -1 &&
+                            (st.f_ffree & 0xffffffff00000000ULL))
+                                return -EOVERFLOW;
+                }
+
+                buf->f_type = st.f_type;
+                buf->f_bsize = st.f_bsize;
+                buf->f_blocks = st.f_blocks;
+                buf->f_bfree = st.f_bfree;
+                buf->f_bavail = st.f_bavail;
+                buf->f_files = st.f_files;
+                buf->f_ffree = st.f_ffree;
+                buf->f_fsid = st.f_fsid;
+                buf->f_namelen = st.f_namelen;
+                buf->f_frsize = st.f_frsize;
+                memset(buf->f_spare, 0, sizeof(buf->f_spare));
+        }
+        return 0;
+}
+
+static int vfs_statfs64(struct super_block *sb, struct statfs64 *buf)
+{
+        struct kstatfs st;
+        int retval;
+
+        retval = vfs_statfs(sb, &st);
+        if (retval)
+                return retval;
+
+        if (sizeof(*buf) == sizeof(st))
+                memcpy(buf, &st, sizeof(st));
+        else {
+                buf->f_type = st.f_type;
+                buf->f_bsize = st.f_bsize;
+                buf->f_blocks = st.f_blocks;
+                buf->f_bfree = st.f_bfree;
+                buf->f_bavail = st.f_bavail;
+                buf->f_files = st.f_files;
+                buf->f_ffree = st.f_ffree;
+                buf->f_fsid = st.f_fsid;
+                buf->f_namelen = st.f_namelen;
+                buf->f_frsize = st.f_frsize;
+                memset(buf->f_spare, 0, sizeof(buf->f_spare));
+        }
+        return 0;
+}
+
+asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf)
+{
+        struct nameidata nd;
+        int error;
+
+        error = user_path_walk(path, &nd);
+        if (!error) {
+                struct statfs tmp;
+                error = vfs_statfs_native(nd.dentry->d_inode->i_sb, &tmp);
+                if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
+                        error = -EFAULT;
+                path_release(&nd);
+        }
+        return error;
+}
+
+
+asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf)
+{
+        struct nameidata nd;
+        long error;
+
+        if (sz != sizeof(*buf))
+                return -EINVAL;
+        error = user_path_walk(path, &nd);
+        if (!error) {
+                struct statfs64 tmp;
+                error = vfs_statfs64(nd.dentry->d_inode->i_sb, &tmp);
+                if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
+                        error = -EFAULT;
+                path_release(&nd);
+        }
+        return error;
+}
+
+
+asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf)
+{
+        struct file * file;
+        struct statfs tmp;
+        int error;
+
+        error = -EBADF;
+        file = fget(fd);
+        if (!file)
+                goto out;
+        error = vfs_statfs_native(file->f_dentry->d_inode->i_sb, &tmp);
+        if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
+                error = -EFAULT;
+        fput(file);
+out:
+        return error;
+}
+
+asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf)
+{
+        struct file * file;
+        struct statfs64 tmp;
+        int error;
+
+        if (sz != sizeof(*buf))
+                return -EINVAL;
+
+        error = -EBADF;
+        file = fget(fd);
+        if (!file)
+                goto out;
+        error = vfs_statfs64(file->f_dentry->d_inode->i_sb, &tmp);
+        if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
+                error = -EFAULT;
+        fput(file);
+out:
+        return error;
+}
+
+int do_truncate(struct dentry *dentry, loff_t length)
+{
+        int err;
+        struct iattr newattrs;
+
+        /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
+        if (length < 0)
+                return -EINVAL;
+
+        newattrs.ia_size = length;
+        newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
+
+        down(&dentry->d_inode->i_sem);
+        err = notify_change(dentry, &newattrs);
+        up(&dentry->d_inode->i_sem);
+        return err;
+}
+
+static inline long do_sys_truncate(const char __user * path, loff_t length)
+{
+        struct nameidata nd;
+        struct inode * inode;
+        int error;
+
+        error = -EINVAL;
+        if (length < 0) /* sorry, but loff_t says... */
+                goto out;
+
+        error = user_path_walk(path, &nd);
+        if (error)
+                goto out;
+        inode = nd.dentry->d_inode;
+
+        /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
+        error = -EISDIR;
+        if (S_ISDIR(inode->i_mode))
+                goto dput_and_out;
+
+        error = -EINVAL;
+        if (!S_ISREG(inode->i_mode))
+                goto dput_and_out;
+
+        error = permission(inode,MAY_WRITE,&nd);
+        if (error)
+                goto dput_and_out;
+
+        error = -EROFS;
+        if (IS_RDONLY(inode))
+                goto dput_and_out;
+
+        error = -EPERM;
+        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+                goto dput_and_out;
+
+        /*
+         * Make sure that there are no leases.
+         */
+        error = break_lease(inode, FMODE_WRITE);
+        if (error)
+                goto dput_and_out;
+
+        error = get_write_access(inode);
+        if (error)
+                goto dput_and_out;
+
+        error = locks_verify_truncate(inode, NULL, length);
+        if (!error) {
+                DQUOT_INIT(inode);
+                error = do_truncate(nd.dentry, length);
+        }
+        put_write_access(inode);
+
+dput_and_out:
+        path_release(&nd);
+out:
+        return error;
+}
+
+asmlinkage long sys_truncate(const char __user * path, unsigned long length)
+{
+        /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
+        return do_sys_truncate(path, (long)length);
+}
+
+static inline long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
+{
+        struct inode * inode;
+        struct dentry *dentry;
+        struct file * file;
+        int error;
+
+        error = -EINVAL;
+        if (length < 0)
+                goto out;
+        error = -EBADF;
+        file = fget(fd);
+        if (!file)
+                goto out;
+
+        /* explicitly opened as large or we are on 64-bit box */
+        if (file->f_flags & O_LARGEFILE)
+                small = 0;
+
+        dentry = file->f_dentry;
+        inode = dentry->d_inode;
+        error = -EINVAL;
+        if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
+                goto out_putf;
+
+        error = -EINVAL;
+        /* Cannot ftruncate over 2^31 bytes without large file support */
+        if (small && length > MAX_NON_LFS)
+                goto out_putf;
+
+        error = -EPERM;
+        if (IS_APPEND(inode))
+                goto out_putf;
+
+        error = locks_verify_truncate(inode, file, length);
+        if (!error)
+                error = do_truncate(dentry, length);
+out_putf:
+        fput(file);
+out:
+        return error;
+}
+
+asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
+{
+        return do_sys_ftruncate(fd, length, 1);
+}
+
+/* LFS versions of truncate are only needed on 32 bit machines */
+#if BITS_PER_LONG == 32
+asmlinkage long sys_truncate64(const char __user * path, loff_t length)
+{
+        return do_sys_truncate(path, length);
+}
+
+asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
+{
+        return do_sys_ftruncate(fd, length, 0);
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_UTIME
+
+/*
+ * sys_utime() can be implemented in user-level using sys_utimes().
+ * Is this for backwards compatibility?  If so, why not move it
+ * into the appropriate arch directory (for those architectures that
+ * need it).
+ */
+
+/* If times==NULL, set access and modification to current time,
+ * must be owner or have write permission.
+ * Else, update from *times, must be owner or super user.
+ */
+asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times)
+{
+        int error;
+        struct nameidata nd;
+        struct inode * inode;
+        struct iattr newattrs;
+
+        error = user_path_walk(filename, &nd);
+        if (error)
+                goto out;
+        inode = nd.dentry->d_inode;
+
+        error = -EROFS;
+        if (IS_RDONLY(inode))
+                goto dput_and_out;
+
+        /* Don't worry, the checks are done in inode_change_ok() */
+        newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
+        if (times) {
+                error = -EPERM;
+                if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                        goto dput_and_out;
+
+                error = get_user(newattrs.ia_atime.tv_sec, &times->actime);
+                newattrs.ia_atime.tv_nsec = 0;
+                if (!error) 
+                        error = get_user(newattrs.ia_mtime.tv_sec, &times->modtime);
+                newattrs.ia_mtime.tv_nsec = 0;
+                if (error)
+                        goto dput_and_out;
+
+                newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
+        } else {
+                error = -EACCES;
+                if (IS_IMMUTABLE(inode))
+                        goto dput_and_out;
+
+                if (current->fsuid != inode->i_uid &&
+                    (error = permission(inode,MAY_WRITE,&nd)) != 0)
+                        goto dput_and_out;
+        }
+        down(&inode->i_sem);
+        error = notify_change(nd.dentry, &newattrs);
+        up(&inode->i_sem);
+dput_and_out:
+        path_release(&nd);
+out:
+        return error;
+}
+
+#endif
+
+/* If times==NULL, set access and modification to current time,
+ * must be owner or have write permission.
+ * Else, update from *times, must be owner or super user.
+ */
+long do_utimes(char __user * filename, struct timeval * times)
+{
+        int error;
+        struct nameidata nd;
+        struct inode * inode;
+        struct iattr newattrs;
+
+        error = user_path_walk(filename, &nd);
+
+        if (error)
+                goto out;
+        inode = nd.dentry->d_inode;
+
+        error = -EROFS;
+        if (IS_RDONLY(inode))
+                goto dput_and_out;
+
+        /* Don't worry, the checks are done in inode_change_ok() */
+        newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
+        if (times) {
+                error = -EPERM;
+                if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                        goto dput_and_out;
+
+                newattrs.ia_atime.tv_sec = times[0].tv_sec;
+                newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000;
+                newattrs.ia_mtime.tv_sec = times[1].tv_sec;
+                newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000;
+                newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
+        } else {
+                error = -EACCES;
+                if (IS_IMMUTABLE(inode))
+                        goto dput_and_out;
+
+                if (current->fsuid != inode->i_uid &&
+                    (error = permission(inode,MAY_WRITE,&nd)) != 0)
+                        goto dput_and_out;
+        }
+        down(&inode->i_sem);
+        error = notify_change(nd.dentry, &newattrs);
+        up(&inode->i_sem);
+dput_and_out:
+        path_release(&nd);
+out:
+        return error;
+}
+
+asmlinkage long sys_utimes(char __user * filename, struct timeval __user * utimes)
+{
+        struct timeval times[2];
+
+        if (utimes && copy_from_user(&times, utimes, sizeof(times)))
+                return -EFAULT;
+        return do_utimes(filename, utimes ? times : NULL);
+}
+
+
+/*
+ * access() needs to use the real uid/gid, not the effective uid/gid.
+ * We do this by temporarily clearing all FS-related capabilities and
+ * switching the fsuid/fsgid around to the real ones.
+ */
+asmlinkage long sys_access(const char __user * filename, int mode)
+{
+        struct nameidata nd;
+        int old_fsuid, old_fsgid;
+        kernel_cap_t old_cap;
+        int res;
+
+        if (mode & ~S_IRWXO)    /* where's F_OK, X_OK, W_OK, R_OK? */
+                return -EINVAL;
+
+        old_fsuid = current->fsuid;
+        old_fsgid = current->fsgid;
+        old_cap = current->cap_effective;
+
+        current->fsuid = current->uid;
+        current->fsgid = current->gid;
+
+        /*
+         * Clear the capabilities if we switch to a non-root user
+         *
+         * FIXME: There is a race here against sys_capset.  The
+         * capabilities can change yet we will restore the old
+         * value below.  We should hold task_capabilities_lock,
+         * but we cannot because user_path_walk can sleep.
+         */
+        if (current->uid)
+                cap_clear(current->cap_effective);
+        else
+                current->cap_effective = current->cap_permitted;
+
+        res = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
+        if (!res) {
+                res = permission(nd.dentry->d_inode, mode, &nd);
+                /* SuS v2 requires we report a read only fs too */
+                if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode)
+                   && !special_file(nd.dentry->d_inode->i_mode))
+                        res = -EROFS;
+                path_release(&nd);
+        }
+
+        current->fsuid = old_fsuid;
+        current->fsgid = old_fsgid;
+        current->cap_effective = old_cap;
+
+        return res;
+}
+
+asmlinkage long sys_chdir(const char __user * filename)
+{
+        struct nameidata nd;
+        int error;
+
+        error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd);
+        if (error)
+                goto out;
+
+        error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
+        if (error)
+                goto dput_and_out;
+
+        set_fs_pwd(current->fs, nd.mnt, nd.dentry);
+
+dput_and_out:
+        path_release(&nd);
+out:
+        return error;
+}
+
+asmlinkage long sys_fchdir(unsigned int fd)
+{
+        struct file *file;
+        struct dentry *dentry;
+        struct inode *inode;
+        struct vfsmount *mnt;
+        int error;
+
+        error = -EBADF;
+        file = fget(fd);
+        if (!file)
+                goto out;
+
+        dentry = file->f_dentry;
+        mnt = file->f_vfsmnt;
+        inode = dentry->d_inode;
+
+        error = -ENOTDIR;
+        if (!S_ISDIR(inode->i_mode))
+                goto out_putf;
+
+        error = permission(inode, MAY_EXEC, NULL);
+        if (!error)
+                set_fs_pwd(current->fs, mnt, dentry);
+out_putf:
+        fput(file);
+out:
+        return error;
+}
+
+asmlinkage long sys_chroot(const char __user * filename)
+{
+        struct nameidata nd;
+        int error;
+
+        error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
+        if (error)
+                goto out;
+
+        error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
+        if (error)
+                goto dput_and_out;
+
+        error = -EPERM;
+        if (!capable(CAP_SYS_CHROOT))
+                goto dput_and_out;
+
+        set_fs_root(current->fs, nd.mnt, nd.dentry);
+        set_fs_altroot();
+        error = 0;
+dput_and_out:
+        path_release(&nd);
+out:
+        return error;
+}
+
+asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
+{
+        struct inode * inode;
+        struct dentry * dentry;
+        struct file * file;
+        int err = -EBADF;
+        struct iattr newattrs;
+
+        file = fget(fd);
+        if (!file)
+                goto out;
+
+        dentry = file->f_dentry;
+        inode = dentry->d_inode;
+
+        err = -EROFS;
+        if (IS_RDONLY(inode))
+                goto out_putf;
+        err = -EPERM;
+        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+                goto out_putf;
+        down(&inode->i_sem);
+        if (mode == (mode_t) -1)
+                mode = inode->i_mode;
+        newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
+        newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
+        err = notify_change(dentry, &newattrs);
+        up(&inode->i_sem);
+
+out_putf:
+        fput(file);
+out:
+        return err;
+}
+
+asmlinkage long sys_chmod(const char __user * filename, mode_t mode)
+{
+        struct nameidata nd;
+        struct inode * inode;
+        int error;
+        struct iattr newattrs;
+
+        error = user_path_walk(filename, &nd);
+        if (error)
+                goto out;
+        inode = nd.dentry->d_inode;
+
+        error = -EROFS;
+        if (IS_RDONLY(inode))
+                goto dput_and_out;
+
+        error = -EPERM;
+        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+                goto dput_and_out;
+
+        down(&inode->i_sem);
+        if (mode == (mode_t) -1)
+                mode = inode->i_mode;
+        newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
+        newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
+        error = notify_change(nd.dentry, &newattrs);
+        up(&inode->i_sem);
+
+dput_and_out:
+        path_release(&nd);
+out:
+        return error;
+}
+
+static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
+{
+        struct inode * inode;
+        int error;
+        struct iattr newattrs;
+
+        error = -ENOENT;
+        if (!(inode = dentry->d_inode)) {
+                printk(KERN_ERR "chown_common: NULL inode\n");
+                goto out;
+        }
+        error = -EROFS;
+        if (IS_RDONLY(inode))
+                goto out;
+        error = -EPERM;
+        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+                goto out;
+        newattrs.ia_valid =  ATTR_CTIME;
+        if (user != (uid_t) -1) {
+                newattrs.ia_valid |= ATTR_UID;
+                newattrs.ia_uid = user;
+        }
+        if (group != (gid_t) -1) {
+                newattrs.ia_valid |= ATTR_GID;
+                newattrs.ia_gid = group;
+        }
+        if (!S_ISDIR(inode->i_mode))
+                newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID;
+        down(&inode->i_sem);
+        error = notify_change(dentry, &newattrs);
+        up(&inode->i_sem);
+out:
+        return error;
+}
+
+asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
+{
+        struct nameidata nd;
+        int error;
+
+        error = user_path_walk(filename, &nd);
+        if (!error) {
+                error = chown_common(nd.dentry, user, group);
+                path_release(&nd);
+        }
+        return error;
+}
+
+asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
+{
+        struct nameidata nd;
+        int error;
+
+        error = user_path_walk_link(filename, &nd);
+        if (!error) {
+                error = chown_common(nd.dentry, user, group);
+                path_release(&nd);
+        }
+        return error;
+}
+
+
+asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
+{
+        struct file * file;
+        int error = -EBADF;
+
+        file = fget(fd);
+        if (file) {
+                error = chown_common(file->f_dentry, user, group);
+                fput(file);
+        }
+        return error;
+}
+
+/*
+ * Note that while the flag value (low two bits) for sys_open means:
+ *      00 - read-only
+ *      01 - write-only
+ *      10 - read-write
+ *      11 - special
+ * it is changed into
+ *      00 - no permissions needed
+ *      01 - read-permission
+ *      10 - write-permission
+ *      11 - read-write
+ * for the internal routines (ie open_namei()/follow_link() etc). 00 is
+ * used by symlinks.
+ */
+struct file *filp_open(const char * filename, int flags, int mode)
+{
+        int namei_flags, error;
+        struct nameidata nd;
+
+        namei_flags = flags;
+        if ((namei_flags+1) & O_ACCMODE)
+                namei_flags++;
+        if (namei_flags & O_TRUNC)
+                namei_flags |= 2;
+
+        error = open_namei(filename, namei_flags, mode, &nd);
+        if (!error)
+                return dentry_open(nd.dentry, nd.mnt, flags);
+
+        return ERR_PTR(error);
+}
+
+EXPORT_SYMBOL(filp_open);
+
+struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+{
+        struct file * f;
+        struct inode *inode;
+        int error;
+
+        error = -ENFILE;
+        f = get_empty_filp();
+        if (!f)
+                goto cleanup_dentry;
+        f->f_flags = flags;
+        f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
+        inode = dentry->d_inode;
+        if (f->f_mode & FMODE_WRITE) {
+                error = get_write_access(inode);
+                if (error)
+                        goto cleanup_file;
+        }
+
+        f->f_mapping = inode->i_mapping;
+        f->f_dentry = dentry;
+        f->f_vfsmnt = mnt;
+        f->f_pos = 0;
+        f->f_op = fops_get(inode->i_fop);
+        file_move(f, &inode->i_sb->s_files);
+
+        if (f->f_op && f->f_op->open) {
+                error = f->f_op->open(inode,f);
+                if (error)
+                        goto cleanup_all;
+        }
+        f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
+
+        file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
+
+        /* NB: we're sure to have correct a_ops only after f_op->open */
+        if (f->f_flags & O_DIRECT) {
+                if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) {
+                        fput(f);
+                        f = ERR_PTR(-EINVAL);
+                }
+        }
+
+        return f;
+
+cleanup_all:
+        fops_put(f->f_op);
+        if (f->f_mode & FMODE_WRITE)
+                put_write_access(inode);
+        file_kill(f);
+        f->f_dentry = NULL;
+        f->f_vfsmnt = NULL;
+cleanup_file:
+        put_filp(f);
+cleanup_dentry:
+        dput(dentry);
+        mntput(mnt);
+        return ERR_PTR(error);
+}
+
+EXPORT_SYMBOL(dentry_open);
+
+/*
+ * Find an empty file descriptor entry, and mark it busy.
+ */
+int get_unused_fd(void)
+{
+        struct files_struct * files = current->files;
+        int fd, error;
+
+        error = -EMFILE;
+        spin_lock(&files->file_lock);
+
+repeat:
+        fd = find_next_zero_bit(files->open_fds->fds_bits, 
+                                files->max_fdset, 
+                                files->next_fd);
+
+        /*
+         * N.B. For clone tasks sharing a files structure, this test
+         * will limit the total number of files that can be opened.
+         */
+        if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+                goto out;
+
+        /* Do we need to expand the fd array or fd set?  */
+        error = expand_files(files, fd);
+        if (error < 0)
+                goto out;
+
+        if (error) {
+                /*
+                 * If we needed to expand the fs array we
+                 * might have blocked - try again.
+                 */
+                error = -EMFILE;
+                goto repeat;
+        }
+
+        FD_SET(fd, files->open_fds);
+        FD_CLR(fd, files->close_on_exec);
+        files->next_fd = fd + 1;
+#if 1
+        /* Sanity check */
+        if (files->fd[fd] != NULL) {
+                printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
+                files->fd[fd] = NULL;
+        }
+#endif
+        error = fd;
+
+out:
+        spin_unlock(&files->file_lock);
+        return error;
+}
+
+EXPORT_SYMBOL(get_unused_fd);
+
+static inline void __put_unused_fd(struct files_struct *files, unsigned int fd)
+{
+        __FD_CLR(fd, files->open_fds);
+        if (fd < files->next_fd)
+                files->next_fd = fd;
+}
+
+void fastcall put_unused_fd(unsigned int fd)
+{
+        struct files_struct *files = current->files;
+        spin_lock(&files->file_lock);
+        __put_unused_fd(files, fd);
+        spin_unlock(&files->file_lock);
+}
+
+EXPORT_SYMBOL(put_unused_fd);
+
+/*
+ * Install a file pointer in the fd array.  
+ *
+ * The VFS is full of places where we drop the files lock between
+ * setting the open_fds bitmap and installing the file in the file
+ * array.  At any such point, we are vulnerable to a dup2() race
+ * installing a file in the array before us.  We need to detect this and
+ * fput() the struct file we are about to overwrite in this case.
+ *
+ * It should never happen - if we allow dup2() do it, _really_ bad things
+ * will follow.
+ */
+
+void fastcall fd_install(unsigned int fd, struct file * file)
+{
+        struct files_struct *files = current->files;
+        spin_lock(&files->file_lock);
+        if (unlikely(files->fd[fd] != NULL))
+                BUG();
+        files->fd[fd] = file;
+        spin_unlock(&files->file_lock);
+}
+
+EXPORT_SYMBOL(fd_install);
+
+asmlinkage long sys_open(const char __user * filename, int flags, int mode)
+{
+        char * tmp;
+        int fd, error;
+
+#if BITS_PER_LONG != 32
+        flags |= O_LARGEFILE;
+#endif
+        tmp = getname(filename);
+        fd = PTR_ERR(tmp);
+        if (!IS_ERR(tmp)) {
+                fd = get_unused_fd();
+                if (fd >= 0) {
+                        struct file *f = filp_open(tmp, flags, mode);
+                        error = PTR_ERR(f);
+                        if (IS_ERR(f))
+                                goto out_error;
+                        fd_install(fd, f);
+                }
+out:
+                putname(tmp);
+        }
+        return fd;
+
+out_error:
+        put_unused_fd(fd);
+        fd = error;
+        goto out;
+}
+EXPORT_SYMBOL_GPL(sys_open);
+
+#ifndef __alpha__
+
+/*
+ * For backward compatibility?  Maybe this should be moved
+ * into arch/i386 instead?
+ */
+asmlinkage long sys_creat(const char __user * pathname, int mode)
+{
+        return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
+}
+
+#endif
+
+/*
+ * "id" is the POSIX thread ID. We use the
+ * files pointer for this..
+ */
+int filp_close(struct file *filp, fl_owner_t id)
+{
+        int retval;
+
+        /* Report and clear outstanding errors */
+        retval = filp->f_error;
+        if (retval)
+                filp->f_error = 0;
+
+        if (!file_count(filp)) {
+                printk(KERN_ERR "VFS: Close: file count is 0\n");
+                return retval;
+        }
+
+        if (filp->f_op && filp->f_op->flush) {
+                int err = filp->f_op->flush(filp);
+                if (!retval)
+                        retval = err;
+        }
+
+        dnotify_flush(filp, id);
+        locks_remove_posix(filp, id);
+        fput(filp);
+        return retval;
+}
+
+EXPORT_SYMBOL(filp_close);
+
+/*
+ * Careful here! We test whether the file pointer is NULL before
+ * releasing the fd. This ensures that one clone task can't release
+ * an fd while another clone is opening it.
+ */
+asmlinkage long sys_close(unsigned int fd)
+{
+        struct file * filp;
+        struct files_struct *files = current->files;
+
+        spin_lock(&files->file_lock);
+        if (fd >= files->max_fds)
+                goto out_unlock;
+        filp = files->fd[fd];
+        if (!filp)
+                goto out_unlock;
+        files->fd[fd] = NULL;
+        FD_CLR(fd, files->close_on_exec);
+        __put_unused_fd(files, fd);
+        spin_unlock(&files->file_lock);
+        return filp_close(filp, files);
+
+out_unlock:
+        spin_unlock(&files->file_lock);
+        return -EBADF;
+}
+
+EXPORT_SYMBOL(sys_close);
+
+/*
+ * This routine simulates a hangup on the tty, to arrange that users
+ * are given clean terminals at login time.
+ */
+asmlinkage long sys_vhangup(void)
+{
+        if (capable(CAP_SYS_TTY_CONFIG)) {
+                tty_vhangup(current->signal->tty);
+                return 0;
+        }
+        return -EPERM;
+}
+
+/*
+ * Called when an inode is about to be open.
+ * We use this to disallow opening large files on 32bit systems if
+ * the caller didn't specify O_LARGEFILE.  On 64bit systems we force
+ * on this flag in sys_open.
+ */
+int generic_file_open(struct inode * inode, struct file * filp)
+{
+        if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
+                return -EFBIG;
+        return 0;
+}
+
+EXPORT_SYMBOL(generic_file_open);
+
+/*
+ * This is used by subsystems that don't want seekable
+ * file descriptors
+ */
+int nonseekable_open(struct inode *inode, struct file *filp)
+{
+        filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
+        return 0;
+}
+
+EXPORT_SYMBOL(nonseekable_open);