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Diffstat (limited to 'cleopatre/linux-2.6.25.10-spc300/fs/open.c')
-rw-r--r--cleopatre/linux-2.6.25.10-spc300/fs/open.c1205
1 files changed, 1205 insertions, 0 deletions
diff --git a/cleopatre/linux-2.6.25.10-spc300/fs/open.c b/cleopatre/linux-2.6.25.10-spc300/fs/open.c
new file mode 100644
index 0000000000..3fa4e4ffce
--- /dev/null
+++ b/cleopatre/linux-2.6.25.10-spc300/fs/open.c
@@ -0,0 +1,1205 @@
+/*
+ * linux/fs/open.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ */
+
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/quotaops.h>
+#include <linux/fsnotify.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/namei.h>
+#include <linux/backing-dev.h>
+#include <linux/capability.h>
+#include <linux/security.h>
+#include <linux/mount.h>
+#include <linux/vfs.h>
+#include <linux/fcntl.h>
+#include <asm/uaccess.h>
+#include <linux/fs.h>
+#include <linux/personality.h>
+#include <linux/pagemap.h>
+#include <linux/syscalls.h>
+#include <linux/rcupdate.h>
+#include <linux/audit.h>
+#include <linux/falloc.h>
+
+int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ int retval = -ENODEV;
+
+ if (dentry) {
+ retval = -ENOSYS;
+ if (dentry->d_sb->s_op->statfs) {
+ memset(buf, 0, sizeof(*buf));
+ retval = security_sb_statfs(dentry);
+ if (retval)
+ return retval;
+ retval = dentry->d_sb->s_op->statfs(dentry, 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 dentry *dentry, struct statfs *buf)
+{
+ struct kstatfs st;
+ int retval;
+
+ retval = vfs_statfs(dentry, &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 dentry *dentry, struct statfs64 *buf)
+{
+ struct kstatfs st;
+ int retval;
+
+ retval = vfs_statfs(dentry, &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.path.dentry, &tmp);
+ if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
+ error = -EFAULT;
+ path_put(&nd.path);
+ }
+ 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.path.dentry, &tmp);
+ if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
+ error = -EFAULT;
+ path_put(&nd.path);
+ }
+ 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_path.dentry, &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_path.dentry, &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, unsigned int time_attrs,
+ struct file *filp)
+{
+ 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 | time_attrs;
+ if (filp) {
+ newattrs.ia_file = filp;
+ newattrs.ia_valid |= ATTR_FILE;
+ }
+
+ /* Remove suid/sgid on truncate too */
+ newattrs.ia_valid |= should_remove_suid(dentry);
+
+ mutex_lock(&dentry->d_inode->i_mutex);
+ err = notify_change(dentry, &newattrs);
+ mutex_unlock(&dentry->d_inode->i_mutex);
+ return err;
+}
+
+static 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.path.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 = vfs_permission(&nd, MAY_WRITE);
+ 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;
+
+ error = get_write_access(inode);
+ if (error)
+ goto dput_and_out;
+
+ /*
+ * Make sure that there are no leases. get_write_access() protects
+ * against the truncate racing with a lease-granting setlease().
+ */
+ error = break_lease(inode, FMODE_WRITE);
+ if (error)
+ goto put_write_and_out;
+
+ error = locks_verify_truncate(inode, NULL, length);
+ if (!error) {
+ DQUOT_INIT(inode);
+ error = do_truncate(nd.path.dentry, length, 0, NULL);
+ }
+
+put_write_and_out:
+ put_write_access(inode);
+dput_and_out:
+ path_put(&nd.path);
+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 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_path.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, ATTR_MTIME|ATTR_CTIME, file);
+out_putf:
+ fput(file);
+out:
+ return error;
+}
+
+asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
+{
+ long ret = do_sys_ftruncate(fd, length, 1);
+ /* avoid REGPARM breakage on x86: */
+ asmlinkage_protect(2, ret, fd, length);
+ return ret;
+}
+
+/* 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)
+{
+ long ret = do_sys_ftruncate(fd, length, 0);
+ /* avoid REGPARM breakage on x86: */
+ asmlinkage_protect(2, ret, fd, length);
+ return ret;
+}
+#endif
+
+asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
+{
+ struct file *file;
+ struct inode *inode;
+ long ret = -EINVAL;
+
+ if (offset < 0 || len <= 0)
+ goto out;
+
+ /* Return error if mode is not supported */
+ ret = -EOPNOTSUPP;
+ if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
+ goto out;
+
+ ret = -EBADF;
+ file = fget(fd);
+ if (!file)
+ goto out;
+ if (!(file->f_mode & FMODE_WRITE))
+ goto out_fput;
+ /*
+ * Revalidate the write permissions, in case security policy has
+ * changed since the files were opened.
+ */
+ ret = security_file_permission(file, MAY_WRITE);
+ if (ret)
+ goto out_fput;
+
+ inode = file->f_path.dentry->d_inode;
+
+ ret = -ESPIPE;
+ if (S_ISFIFO(inode->i_mode))
+ goto out_fput;
+
+ ret = -ENODEV;
+ /*
+ * Let individual file system decide if it supports preallocation
+ * for directories or not.
+ */
+ if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
+ goto out_fput;
+
+ ret = -EFBIG;
+ /* Check for wrap through zero too */
+ if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
+ goto out_fput;
+
+ if (inode->i_op && inode->i_op->fallocate)
+ ret = inode->i_op->fallocate(inode, mode, offset, len);
+ else
+ ret = -EOPNOTSUPP;
+
+out_fput:
+ fput(file);
+out:
+ return ret;
+}
+
+/*
+ * 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_faccessat(int dfd, 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_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
+ if (res)
+ goto out;
+
+ res = vfs_permission(&nd, mode);
+ /* SuS v2 requires we report a read only fs too */
+ if(res || !(mode & S_IWOTH) ||
+ special_file(nd.path.dentry->d_inode->i_mode))
+ goto out_path_release;
+
+ if(IS_RDONLY(nd.path.dentry->d_inode))
+ res = -EROFS;
+
+out_path_release:
+ path_put(&nd.path);
+out:
+ current->fsuid = old_fsuid;
+ current->fsgid = old_fsgid;
+ current->cap_effective = old_cap;
+
+ return res;
+}
+
+asmlinkage long sys_access(const char __user *filename, int mode)
+{
+ return sys_faccessat(AT_FDCWD, filename, mode);
+}
+
+asmlinkage long sys_chdir(const char __user * filename)
+{
+ struct nameidata nd;
+ int error;
+
+ error = __user_walk(filename,
+ LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
+ if (error)
+ goto out;
+
+ error = vfs_permission(&nd, MAY_EXEC);
+ if (error)
+ goto dput_and_out;
+
+ set_fs_pwd(current->fs, &nd.path);
+
+dput_and_out:
+ path_put(&nd.path);
+out:
+ return error;
+}
+
+asmlinkage long sys_fchdir(unsigned int fd)
+{
+ struct file *file;
+ struct inode *inode;
+ int error;
+
+ error = -EBADF;
+ file = fget(fd);
+ if (!file)
+ goto out;
+
+ inode = file->f_path.dentry->d_inode;
+
+ error = -ENOTDIR;
+ if (!S_ISDIR(inode->i_mode))
+ goto out_putf;
+
+ error = file_permission(file, MAY_EXEC);
+ if (!error)
+ set_fs_pwd(current->fs, &file->f_path);
+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 = vfs_permission(&nd, MAY_EXEC);
+ if (error)
+ goto dput_and_out;
+
+ error = -EPERM;
+ if (!capable(CAP_SYS_CHROOT))
+ goto dput_and_out;
+
+ set_fs_root(current->fs, &nd.path);
+ set_fs_altroot();
+ error = 0;
+dput_and_out:
+ path_put(&nd.path);
+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_path.dentry;
+ inode = dentry->d_inode;
+
+ audit_inode(NULL, dentry);
+
+ err = -EROFS;
+ if (IS_RDONLY(inode))
+ goto out_putf;
+ err = -EPERM;
+ if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+ goto out_putf;
+ mutex_lock(&inode->i_mutex);
+ 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);
+ mutex_unlock(&inode->i_mutex);
+
+out_putf:
+ fput(file);
+out:
+ return err;
+}
+
+asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
+ mode_t mode)
+{
+ struct nameidata nd;
+ struct inode * inode;
+ int error;
+ struct iattr newattrs;
+
+ error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
+ if (error)
+ goto out;
+ inode = nd.path.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;
+
+ mutex_lock(&inode->i_mutex);
+ 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.path.dentry, &newattrs);
+ mutex_unlock(&inode->i_mutex);
+
+dput_and_out:
+ path_put(&nd.path);
+out:
+ return error;
+}
+
+asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
+{
+ return sys_fchmodat(AT_FDCWD, filename, mode);
+}
+
+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 | ATTR_KILL_PRIV;
+ mutex_lock(&inode->i_mutex);
+ error = notify_change(dentry, &newattrs);
+ mutex_unlock(&inode->i_mutex);
+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)
+ goto out;
+ error = chown_common(nd.path.dentry, user, group);
+ path_put(&nd.path);
+out:
+ return error;
+}
+
+asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
+ gid_t group, int flag)
+{
+ struct nameidata nd;
+ int error = -EINVAL;
+ int follow;
+
+ if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
+ goto out;
+
+ follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
+ error = __user_walk_fd(dfd, filename, follow, &nd);
+ if (error)
+ goto out;
+ error = chown_common(nd.path.dentry, user, group);
+ path_put(&nd.path);
+out:
+ 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)
+ goto out;
+ error = chown_common(nd.path.dentry, user, group);
+ path_put(&nd.path);
+out:
+ return error;
+}
+
+
+asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
+{
+ struct file * file;
+ int error = -EBADF;
+ struct dentry * dentry;
+
+ file = fget(fd);
+ if (!file)
+ goto out;
+
+ dentry = file->f_path.dentry;
+ audit_inode(NULL, dentry);
+ error = chown_common(dentry, user, group);
+ fput(file);
+out:
+ return error;
+}
+
+static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+ int flags, struct file *f,
+ int (*open)(struct inode *, struct file *))
+{
+ struct inode *inode;
+ int error;
+
+ 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_path.dentry = dentry;
+ f->f_path.mnt = mnt;
+ f->f_pos = 0;
+ f->f_op = fops_get(inode->i_fop);
+ file_move(f, &inode->i_sb->s_files);
+
+ error = security_dentry_open(f);
+ if (error)
+ goto cleanup_all;
+
+ if (!open && f->f_op)
+ open = f->f_op->open;
+ if (open) {
+ error = 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) &&
+ (!f->f_mapping->a_ops->get_xip_page))) {
+ 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_path.dentry = NULL;
+ f->f_path.mnt = NULL;
+cleanup_file:
+ put_filp(f);
+ dput(dentry);
+ mntput(mnt);
+ return ERR_PTR(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.
+ */
+static struct file *do_filp_open(int dfd, 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++;
+
+ error = open_namei(dfd, filename, namei_flags, mode, &nd);
+ if (!error)
+ return nameidata_to_filp(&nd, flags);
+
+ return ERR_PTR(error);
+}
+
+struct file *filp_open(const char *filename, int flags, int mode)
+{
+ return do_filp_open(AT_FDCWD, filename, flags, mode);
+}
+EXPORT_SYMBOL(filp_open);
+
+/**
+ * lookup_instantiate_filp - instantiates the open intent filp
+ * @nd: pointer to nameidata
+ * @dentry: pointer to dentry
+ * @open: open callback
+ *
+ * Helper for filesystems that want to use lookup open intents and pass back
+ * a fully instantiated struct file to the caller.
+ * This function is meant to be called from within a filesystem's
+ * lookup method.
+ * Beware of calling it for non-regular files! Those ->open methods might block
+ * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
+ * leading to a deadlock, as nobody can open that fifo anymore, because
+ * another process to open fifo will block on locked parent when doing lookup).
+ * Note that in case of error, nd->intent.open.file is destroyed, but the
+ * path information remains valid.
+ * If the open callback is set to NULL, then the standard f_op->open()
+ * filesystem callback is substituted.
+ */
+struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
+ int (*open)(struct inode *, struct file *))
+{
+ if (IS_ERR(nd->intent.open.file))
+ goto out;
+ if (IS_ERR(dentry))
+ goto out_err;
+ nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
+ nd->intent.open.flags - 1,
+ nd->intent.open.file,
+ open);
+out:
+ return nd->intent.open.file;
+out_err:
+ release_open_intent(nd);
+ nd->intent.open.file = (struct file *)dentry;
+ goto out;
+}
+EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
+
+/**
+ * nameidata_to_filp - convert a nameidata to an open filp.
+ * @nd: pointer to nameidata
+ * @flags: open flags
+ *
+ * Note that this function destroys the original nameidata
+ */
+struct file *nameidata_to_filp(struct nameidata *nd, int flags)
+{
+ struct file *filp;
+
+ /* Pick up the filp from the open intent */
+ filp = nd->intent.open.file;
+ /* Has the filesystem initialised the file for us? */
+ if (filp->f_path.dentry == NULL)
+ filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
+ NULL);
+ else
+ path_put(&nd->path);
+ return filp;
+}
+
+/*
+ * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
+ * error.
+ */
+struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+{
+ int error;
+ struct file *f;
+
+ /*
+ * We must always pass in a valid mount pointer. Historically
+ * callers got away with not passing it, but we must enforce this at
+ * the earliest possible point now to avoid strange problems deep in the
+ * filesystem stack.
+ */
+ if (!mnt) {
+ printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
+ dump_stack();
+ return ERR_PTR(-EINVAL);
+ }
+
+ error = -ENFILE;
+ f = get_empty_filp();
+ if (f == NULL) {
+ dput(dentry);
+ mntput(mnt);
+ return ERR_PTR(error);
+ }
+
+ return __dentry_open(dentry, mnt, flags, f, NULL);
+}
+EXPORT_SYMBOL(dentry_open);
+
+/*
+ * Find an empty file descriptor entry, and mark it busy.
+ */
+int get_unused_fd_flags(int flags)
+{
+ struct files_struct * files = current->files;
+ int fd, error;
+ struct fdtable *fdt;
+
+ error = -EMFILE;
+ spin_lock(&files->file_lock);
+
+repeat:
+ fdt = files_fdtable(files);
+ fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
+ 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, fdt->open_fds);
+ if (flags & O_CLOEXEC)
+ FD_SET(fd, fdt->close_on_exec);
+ else
+ FD_CLR(fd, fdt->close_on_exec);
+ files->next_fd = fd + 1;
+#if 1
+ /* Sanity check */
+ if (fdt->fd[fd] != NULL) {
+ printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
+ fdt->fd[fd] = NULL;
+ }
+#endif
+ error = fd;
+
+out:
+ spin_unlock(&files->file_lock);
+ return error;
+}
+
+int get_unused_fd(void)
+{
+ return get_unused_fd_flags(0);
+}
+
+EXPORT_SYMBOL(get_unused_fd);
+
+static void __put_unused_fd(struct files_struct *files, unsigned int fd)
+{
+ struct fdtable *fdt = files_fdtable(files);
+ __FD_CLR(fd, fdt->open_fds);
+ if (fd < files->next_fd)
+ files->next_fd = fd;
+}
+
+void 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 fd_install(unsigned int fd, struct file *file)
+{
+ struct files_struct *files = current->files;
+ struct fdtable *fdt;
+ spin_lock(&files->file_lock);
+ fdt = files_fdtable(files);
+ BUG_ON(fdt->fd[fd] != NULL);
+ rcu_assign_pointer(fdt->fd[fd], file);
+ spin_unlock(&files->file_lock);
+}
+
+EXPORT_SYMBOL(fd_install);
+
+long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
+{
+ char *tmp = getname(filename);
+ int fd = PTR_ERR(tmp);
+
+ if (!IS_ERR(tmp)) {
+ fd = get_unused_fd_flags(flags);
+ if (fd >= 0) {
+ struct file *f = do_filp_open(dfd, tmp, flags, mode);
+ if (IS_ERR(f)) {
+ put_unused_fd(fd);
+ fd = PTR_ERR(f);
+ } else {
+ fsnotify_open(f->f_path.dentry);
+ fd_install(fd, f);
+ }
+ }
+ putname(tmp);
+ }
+ return fd;
+}
+
+asmlinkage long sys_open(const char __user *filename, int flags, int mode)
+{
+ long ret;
+
+ if (force_o_largefile())
+ flags |= O_LARGEFILE;
+
+ ret = do_sys_open(AT_FDCWD, filename, flags, mode);
+ /* avoid REGPARM breakage on x86: */
+ asmlinkage_protect(3, ret, filename, flags, mode);
+ return ret;
+}
+
+asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
+ int mode)
+{
+ long ret;
+
+ if (force_o_largefile())
+ flags |= O_LARGEFILE;
+
+ ret = do_sys_open(dfd, filename, flags, mode);
+ /* avoid REGPARM breakage on x86: */
+ asmlinkage_protect(4, ret, dfd, filename, flags, mode);
+ return ret;
+}
+
+#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 = 0;
+
+ if (!file_count(filp)) {
+ printk(KERN_ERR "VFS: Close: file count is 0\n");
+ return 0;
+ }
+
+ if (filp->f_op && filp->f_op->flush)
+ retval = filp->f_op->flush(filp, id);
+
+ 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;
+ struct fdtable *fdt;
+ int retval;
+
+ spin_lock(&files->file_lock);
+ fdt = files_fdtable(files);
+ if (fd >= fdt->max_fds)
+ goto out_unlock;
+ filp = fdt->fd[fd];
+ if (!filp)
+ goto out_unlock;
+ rcu_assign_pointer(fdt->fd[fd], NULL);
+ FD_CLR(fd, fdt->close_on_exec);
+ __put_unused_fd(files, fd);
+ spin_unlock(&files->file_lock);
+ retval = filp_close(filp, files);
+
+ /* can't restart close syscall because file table entry was cleared */
+ if (unlikely(retval == -ERESTARTSYS ||
+ retval == -ERESTARTNOINTR ||
+ retval == -ERESTARTNOHAND ||
+ retval == -ERESTART_RESTARTBLOCK))
+ retval = -EINTR;
+
+ return retval;
+
+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)) {
+ /* XXX: this needs locking */
+ 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 -EOVERFLOW;
+ 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);