fs/sysv/file.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  linux/fs/sysv/file.c
0004  *
0005  *  minix/file.c
0006  *  Copyright (C) 1991, 1992  Linus Torvalds
0007  *
0008  *  coh/file.c
0009  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
0010  *
0011  *  sysv/file.c
0012  *  Copyright (C) 1993  Bruno Haible
0013  *
0014  *  SystemV/Coherent regular file handling primitives
0015  */
0016
0017 #include "sysv.h"
0018
0019 /*
0020  * We have mostly NULLs here: the current defaults are OK for
0021  * the coh filesystem.
0022  */
0023 const struct file_operations sysv_file_operations = {
0024     .llseek     = generic_file_llseek,
0025     .read_iter  = generic_file_read_iter,
0026     .write_iter = generic_file_write_iter,
0027     .mmap       = generic_file_mmap,
0028     .fsync      = generic_file_fsync,
0029     .splice_read    = generic_file_splice_read,
0030 };
0031
0032 static int sysv_setattr(struct user_namespace *mnt_userns,
0033             struct dentry *dentry, struct iattr *attr)
0034 {
0035     struct inode *inode = d_inode(dentry);
0036     int error;
0037
0038     error = setattr_prepare(&init_user_ns, dentry, attr);
0039     if (error)
0040         return error;
0041
0042     if ((attr->ia_valid & ATTR_SIZE) &&
0043         attr->ia_size != i_size_read(inode)) {
0044         error = inode_newsize_ok(inode, attr->ia_size);
0045         if (error)
0046             return error;
0047         truncate_setsize(inode, attr->ia_size);
0048         sysv_truncate(inode);
0049     }
0050
0051     setattr_copy(&init_user_ns, inode, attr);
0052     mark_inode_dirty(inode);
0053     return 0;
0054 }
0055
0056 const struct inode_operations sysv_file_inode_operations = {
0057     .setattr    = sysv_setattr,
0058     .getattr    = sysv_getattr,
0059 };