lustre/llite/rw24.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Lustre Lite I/O page cache for the 2.4 kernel version
   5  *
   6  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   7  *
   8  *   This file is part of Lustre, http://www.lustre.org.
   9  *
  10  *   Lustre is free software; you can redistribute it and/or
  11  *   modify it under the terms of version 2 of the GNU General Public
  12  *   License as published by the Free Software Foundation.
  13  *
  14  *   Lustre is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *   GNU General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU General Public License
  20  *   along with Lustre; if not, write to the Free Software
  21  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #include <linux/config.h>
  25 #include <linux/kernel.h>
  26 #include <linux/mm.h>
  27 #include <linux/string.h>
  28 #include <linux/stat.h>
  29 #include <linux/errno.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/unistd.h>
  32 #include <linux/version.h>
  33 #include <asm/system.h>
  34 #include <asm/uaccess.h>
  35
  36 #include <linux/fs.h>
  37 #include <linux/iobuf.h>
  38 #include <linux/stat.h>
  39 #include <asm/uaccess.h>
  40 #include <asm/segment.h>
  41 #include <linux/mm.h>
  42 #include <linux/pagemap.h>
  43 #include <linux/smp_lock.h>
  44
  45 #define DEBUG_SUBSYSTEM S_LLITE
  46
  47 #include <lustre_mdc.h>
  48 #include <lustre_lite.h>
  49 #include "llite_internal.h"
  50 #include <linux/lustre_compat25.h>
  51
  52 static int ll_direct_IO_24(int rw,
  53 #ifdef HAVE_DIO_FILE
  54                            struct file *file,
  55 #else
  56                            struct inode *inode,
  57 #endif
  58                            struct kiobuf *iobuf, unsigned long blocknr,
  59                            int blocksize)
  60 {
  61 #ifdef HAVE_DIO_FILE
  62         struct inode *inode = file->f_dentry->d_inode;
  63 #endif
  64         struct ll_inode_info *lli = ll_i2info(inode);
  65         struct lov_stripe_md *lsm = lli->lli_smd;
  66         struct brw_page *pga;
  67         struct obdo oa;
  68         int length, i, flags, rc = 0;
  69         loff_t offset;
  70         ENTRY;
  71
  72         if (!lsm || !lsm->lsm_object_id)
  73                 RETURN(-EBADF);
  74
  75         /* FIXME: io smaller than PAGE_SIZE is broken on ia64 */
  76         if ((iobuf->offset & (PAGE_SIZE - 1)) ||
  77             (iobuf->length & (PAGE_SIZE - 1)))
  78                 RETURN(-EINVAL);
  79
  80         OBD_ALLOC(pga, sizeof(*pga) * iobuf->nr_pages);
  81         if (!pga)
  82                 RETURN(-ENOMEM);
  83
  84         flags = 0 /* | OBD_BRW_DIRECTIO */;
  85         offset = ((obd_off)blocknr << inode->i_blkbits);
  86         length = iobuf->length;
  87         rw = rw ? OBD_BRW_WRITE : OBD_BRW_READ;
  88
  89         for (i = 0, length = iobuf->length; length > 0;
  90              length -= pga[i].count, offset += pga[i].count, i++) { /*i last!*/
  91                 pga[i].pg = iobuf->maplist[i];
  92                 pga[i].off = offset;
  93                 /* To the end of the page, or the length, whatever is less */
  94                 pga[i].count = min_t(int, PAGE_SIZE - (offset & ~PAGE_MASK),
  95                                      length);
  96                 pga[i].flag = flags;
  97                 if (rw == OBD_BRW_READ)
  98                         POISON_PAGE(iobuf->maplist[i], 0x0d);
  99         }
 100
 101         ll_inode_fill_obdo(inode, rw, &oa);
 102
 103         if (rw == OBD_BRW_WRITE)
 104                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 105                                     LPROC_LL_DIRECT_WRITE, iobuf->length);
 106         else
 107                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 108                                     LPROC_LL_DIRECT_READ, iobuf->length);
 109         rc = obd_brw_rqset(rw, ll_i2dtexp(inode), &oa, lsm, iobuf->nr_pages,
 110                            pga, NULL);
 111         if (rc == 0) {
 112                 rc = iobuf->length;
 113                 if (rw == OBD_BRW_WRITE) {
 114                         lov_stripe_lock(lsm);
 115                         obd_adjust_kms(ll_i2dtexp(inode), lsm, offset, 0);
 116                         lov_stripe_unlock(lsm);
 117                 }
 118         }
 119
 120         OBD_FREE(pga, sizeof(*pga) * iobuf->nr_pages);
 121         RETURN(rc);
 122 }
 123
 124 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 125 static int ll_max_readahead(struct inode *inode)
 126 {
 127         return 0;
 128 }
 129 #endif
 130
 131 struct address_space_operations ll_aops = {
 132         .readpage       = ll_readpage,
 133         .direct_IO      = ll_direct_IO_24,
 134         .writepage      = ll_writepage,
 135         .prepare_write  = ll_prepare_write,
 136         .commit_write   = ll_commit_write,
 137         .removepage     = ll_removepage,
 138         .sync_page      = NULL,
 139         .bmap           = NULL,
 140 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 141         .max_readahead  = ll_max_readahead,
 142 #endif
 143 };