fs/sysv/file.c

   1 /*
   2  *  linux/fs/sysv/file.c
   3  *
   4  *  minix/file.c
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *
   7  *  coh/file.c
   8  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
   9  *
  10  *  sysv/file.c
  11  *  Copyright (C) 1993  Bruno Haible
  12  *
  13  *  SystemV/Coherent regular file handling primitives
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/fs.h>
  18 #include <linux/sysv_fs.h>
  19 #include <linux/errno.h>
  20 #include <linux/fcntl.h>
  21 #include <linux/stat.h>
  22 #include <linux/string.h>
  23 #include <linux/locks.h>
  24 #include <linux/pagemap.h>
  25
  26 #include <asm/uaccess.h>
  27
  28 #define NBUF    32
  29
  30 #define MIN(a,b) (((a)<(b))?(a):(b))
  31 #define MAX(a,b) (((a)>(b))?(a):(b))
  32
  33 /*
  34  * Write to a file (through the page cache).
  35  */
  36 static ssize_t
  37 sysv_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
  38 {
  39         return generic_file_write(file, buf, count,
  40                                   ppos, block_write_partial_page);
  41 }
  42
  43 /*
  44  * We have mostly NULLs here: the current defaults are OK for
  45  * the coh filesystem.
  46  */
  47 static struct file_operations sysv_file_operations = {
  48         NULL,                   /* lseek - default */
  49         generic_file_read,      /* read */
  50         sysv_file_write,        /* write */
  51         NULL,                   /* readdir - bad */
  52         NULL,                   /* poll - default */
  53         NULL,                   /* ioctl - default */
  54         generic_file_mmap,      /* mmap */
  55         NULL,                   /* no special open is needed */
  56         NULL,                   /* flush */
  57         NULL,                   /* release */
  58         sysv_sync_file,         /* fsync */
  59         NULL,                   /* fasync */
  60         NULL,                   /* check_media_change */
  61         NULL                    /* revalidate */
  62 };
  63
  64 struct inode_operations sysv_file_inode_operations = {
  65         &sysv_file_operations,  /* default file operations */
  66         NULL,                   /* create */
  67         NULL,                   /* lookup */
  68         NULL,                   /* link */
  69         NULL,                   /* unlink */
  70         NULL,                   /* symlink */
  71         NULL,                   /* mkdir */
  72         NULL,                   /* rmdir */
  73         NULL,                   /* mknod */
  74         NULL,                   /* rename */
  75         NULL,                   /* readlink */
  76         NULL,                   /* follow_link */
  77         sysv_get_block,         /* get_block */
  78         block_read_full_page,   /* readpage */
  79         block_write_full_page,  /* writepage */
  80         block_flushpage,        /* flushpage */
  81         sysv_truncate,          /* truncate */
  82         NULL,                   /* permission */
  83         NULL,                   /* smap */
  84         NULL                    /* revalidate */
  85 };