if (!S_ISREG(inode->i_mode))
goto dput_and_out;
- error = vfs_permission(&nd, MAY_WRITE);
+ error = mnt_want_write(nd.path.mnt);
if (error)
goto dput_and_out;
- error = -EROFS;
- if (IS_RDONLY(inode))
- goto dput_and_out;
+ error = vfs_permission(&nd, MAY_WRITE);
+ if (error)
+ goto mnt_drop_write_and_out;
error = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
- goto dput_and_out;
+ goto mnt_drop_write_and_out;
error = get_write_access(inode);
if (error)
- goto dput_and_out;
+ goto mnt_drop_write_and_out;
/*
* Make sure that there are no leases. get_write_access() protects
put_write_and_out:
put_write_access(inode);
+mnt_drop_write_and_out:
+ mnt_drop_write(nd.path.mnt);
dput_and_out:
path_put(&nd.path);
out:
{
long ret = do_sys_ftruncate(fd, length, 1);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(2, ret, fd, length);
return ret;
}
{
long ret = do_sys_ftruncate(fd, length, 0);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(2, ret, fd, length);
return ret;
}
#endif
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))
+ /*
+ * This is a rare case where using __mnt_is_readonly()
+ * is OK without a mnt_want/drop_write() pair. Since
+ * no actual write to the fs is performed here, we do
+ * not need to telegraph to that to anyone.
+ *
+ * By doing this, we accept that this access is
+ * inherently racy and know that the fs may change
+ * state before we even see this result.
+ */
+ if (__mnt_is_readonly(nd.path.mnt))
res = -EROFS;
out_path_release:
audit_inode(NULL, dentry);
- err = -EROFS;
- if (IS_RDONLY(inode))
+ err = mnt_want_write(file->f_path.mnt);
+ if (err)
goto out_putf;
err = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
- goto out_putf;
+ goto out_drop_write;
mutex_lock(&inode->i_mutex);
if (mode == (mode_t) -1)
mode = inode->i_mode;
err = notify_change(dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
+out_drop_write:
+ mnt_drop_write(file->f_path.mnt);
out_putf:
fput(file);
out:
goto out;
inode = nd.path.dentry->d_inode;
- error = -EROFS;
- if (IS_RDONLY(inode))
+ error = mnt_want_write(nd.path.mnt);
+ if (error)
goto dput_and_out;
error = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
- goto dput_and_out;
+ goto out_drop_write;
mutex_lock(&inode->i_mutex);
if (mode == (mode_t) -1)
error = notify_change(nd.path.dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
+out_drop_write:
+ mnt_drop_write(nd.path.mnt);
dput_and_out:
path_put(&nd.path);
out:
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;
error = user_path_walk(filename, &nd);
if (error)
goto out;
+ error = mnt_want_write(nd.path.mnt);
+ if (error)
+ goto out_release;
error = chown_common(nd.path.dentry, user, group);
+ mnt_drop_write(nd.path.mnt);
+out_release:
path_put(&nd.path);
out:
return error;
error = __user_walk_fd(dfd, filename, follow, &nd);
if (error)
goto out;
+ error = mnt_want_write(nd.path.mnt);
+ if (error)
+ goto out_release;
error = chown_common(nd.path.dentry, user, group);
+ mnt_drop_write(nd.path.mnt);
+out_release:
path_put(&nd.path);
out:
return error;
error = user_path_walk_link(filename, &nd);
if (error)
goto out;
+ error = mnt_want_write(nd.path.mnt);
+ if (error)
+ goto out_release;
error = chown_common(nd.path.dentry, user, group);
+ mnt_drop_write(nd.path.mnt);
+out_release:
path_put(&nd.path);
out:
return error;
if (!file)
goto out;
+ error = mnt_want_write(file->f_path.mnt);
+ if (error)
+ goto out_fput;
dentry = file->f_path.dentry;
audit_inode(NULL, dentry);
error = chown_common(dentry, user, group);
+ mnt_drop_write(file->f_path.mnt);
+out_fput:
fput(file);
out:
return error;
}
+/*
+ * You have to be very careful that these write
+ * counts get cleaned up in error cases and
+ * upon __fput(). This should probably never
+ * be called outside of __dentry_open().
+ */
+static inline int __get_file_write_access(struct inode *inode,
+ struct vfsmount *mnt)
+{
+ int error;
+ error = get_write_access(inode);
+ if (error)
+ return error;
+ /*
+ * Do not take mount writer counts on
+ * special files since no writes to
+ * the mount itself will occur.
+ */
+ if (!special_file(inode->i_mode)) {
+ /*
+ * Balanced in __fput()
+ */
+ error = mnt_want_write(mnt);
+ if (error)
+ put_write_access(inode);
+ }
+ return error;
+}
+
static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
int flags, struct file *f,
int (*open)(struct inode *, struct file *))
FMODE_PREAD | FMODE_PWRITE;
inode = dentry->d_inode;
if (f->f_mode & FMODE_WRITE) {
- error = get_write_access(inode);
+ error = __get_file_write_access(inode, mnt);
if (error)
goto cleanup_file;
+ if (!special_file(inode->i_mode))
+ file_take_write(f);
}
f->f_mapping = inode->i_mapping;
cleanup_all:
fops_put(f->f_op);
- if (f->f_mode & FMODE_WRITE)
+ if (f->f_mode & FMODE_WRITE) {
put_write_access(inode);
+ if (!special_file(inode->i_mode)) {
+ /*
+ * We don't consider this a real
+ * mnt_want/drop_write() pair
+ * because it all happenend right
+ * here, so just reset the state.
+ */
+ file_reset_write(f);
+ mnt_drop_write(mnt);
+ }
+ }
file_kill(f);
f->f_path.dentry = NULL;
f->f_path.mnt = NULL;
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
ret = do_sys_open(AT_FDCWD, filename, flags, mode);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(3, ret, filename, flags, mode);
return ret;
}
ret = do_sys_open(dfd, filename, flags, mode);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(4, ret, dfd, filename, flags, mode);
return ret;
}
projects / linux-2.6-omap-h63xx.git / blobdiff