lustre/obdfs/file.c

   1 /*
   2  *  linux/fs/ext2/file.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/file.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  ext2 fs regular file handling primitives
  16  *
  17  *  64-bit file support on 64-bit platforms by Jakub Jelinek
  18  *      (jj@sunsite.ms.mff.cuni.cz)
  19  */
  20
  21 #include <asm/uaccess.h>
  22 #include <asm/system.h>
  23
  24 #include <linux/errno.h>
  25 #include <linux/fs.h>
  26 #include <linux/ext2_fs.h>
  27 #include <linux/fcntl.h>
  28 #include <linux/sched.h>
  29 #include <linux/stat.h>
  30 #include <linux/locks.h>
  31 #include <linux/mm.h>
  32 #include <linux/pagemap.h>
  33 #include <linux/smp_lock.h>
  34
  35 #include <linux/obd_support.h>
  36 #include <linux/obdfs.h>
  37
  38 static inline void remove_suid(struct inode *inode)
  39 {
  40         unsigned int mode;
  41
  42         /* set S_IGID if S_IXGRP is set, and always set S_ISUID */
  43         mode = (inode->i_mode & S_IXGRP)*(S_ISGID/S_IXGRP) | S_ISUID;
  44
  45         /* was any of the uid bits set? */
  46         mode &= inode->i_mode;
  47         if (mode && !capable(CAP_FSETID)) {
  48                 inode->i_mode &= ~mode;
  49                 mark_inode_dirty(inode);
  50         }
  51 }
  52
  53 /*
  54  * Write to a file (through the page cache).
  55  */
  56 static ssize_t
  57 obdfs_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
  58 {
  59         ssize_t retval;
  60         CDEBUG(D_INODE, "Writing inode %ld, %d bytes, offset %ld\n", file->f_dentry->d_inode->i_ino, count, (long)*ppos);
  61
  62         retval = generic_file_write(file, buf, count,
  63                                     ppos, obdfs_write_one_page);
  64         CDEBUG(D_INODE, "Wrote %d\n", retval);
  65         if (retval > 0) {
  66                 struct inode *inode = file->f_dentry->d_inode;
  67                 remove_suid(inode);
  68                 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
  69                 mark_inode_dirty(inode);
  70         }
  71         EXIT;
  72         return retval;
  73 }
  74
  75 struct file_operations obdfs_file_operations = {
  76         NULL,                   /* lseek - default */
  77         generic_file_read,      /* read */
  78         obdfs_file_write,       /* write  */
  79         NULL,                   /* readdir - bad */
  80         NULL,                   /* poll - default */
  81         NULL,                   /* ioctl */
  82         NULL,                   /* mmap */
  83         NULL,                   /* no special open code */
  84         NULL,                   /* flush */
  85         NULL,                   /* no special release code */
  86         NULL,                   /* fsync */
  87         NULL,                   /* fasync */
  88         NULL,                   /* check_media_change */
  89         NULL                    /* revalidate */
  90 };
  91
  92 struct inode_operations obdfs_file_inode_operations = {
  93         &obdfs_file_operations, /* default directory file-ops */
  94         obdfs_create,           /* create */
  95         obdfs_lookup,           /* lookup */
  96         obdfs_link,             /* link */
  97         obdfs_unlink,           /* unlink */
  98         obdfs_symlink,          /* symlink */
  99         obdfs_mkdir,            /* mkdir */
 100         obdfs_rmdir,            /* rmdir */
 101         obdfs_mknod,            /* mknod */
 102         obdfs_rename,           /* rename */
 103         NULL,                   /* readlink */
 104         NULL,                   /* follow_link */
 105         NULL,                   /* get_block */
 106         obdfs_readpage,         /* readpage */
 107         obdfs_writepage,        /* writepage */
 108         NULL,                   /* truncate */
 109         NULL,                   /* permission */
 110         NULL                    /* revalidate */
 111 };
 112