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 #ifdef HAVE_KERNEL_CONFIG_H
  24 #include <linux/config.h>
  25 #endif
  26 #include <linux/kernel.h>
  27 #include <linux/mm.h>
  28 #include <linux/string.h>
  29 #include <linux/stat.h>
  30 #include <linux/errno.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/unistd.h>
  33 #include <linux/version.h>
  34 #include <asm/system.h>
  35 #include <asm/uaccess.h>
  36
  37 #include <linux/fs.h>
  38 #include <linux/iobuf.h>
  39 #include <linux/stat.h>
  40 #include <asm/uaccess.h>
  41 #include <asm/segment.h>
  42 #include <linux/mm.h>
  43 #include <linux/pagemap.h>
  44 #include <linux/smp_lock.h>
  45
  46 #define DEBUG_SUBSYSTEM S_LLITE
  47
  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, offset_orig;
  70         ENTRY;
  71
  72         if (!lsm || !lsm->lsm_object_id)
  73                 RETURN(-EBADF);
  74
  75         offset = ((obd_off)blocknr << inode->i_blkbits);
  76         offset_orig = offset;
  77         CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size="LPSZ
  78                ", offset=%lld=%llx, pages %u\n",
  79                inode->i_ino, inode->i_generation, inode, iobuf->length,
  80                offset, offset, iobuf->nr_pages);
  81
  82         /* FIXME: io smaller than CFS_PAGE_SIZE is broken on ia64 */
  83         if ((iobuf->offset & (~CFS_PAGE_MASK)) ||
  84             (iobuf->length & (~CFS_PAGE_MASK)))
  85                 RETURN(-EINVAL);
  86
  87         OBD_ALLOC(pga, sizeof(*pga) * iobuf->nr_pages);
  88         if (!pga)
  89                 RETURN(-ENOMEM);
  90
  91         flags = 0 /* | OBD_BRW_DIRECTIO */;
  92         length = iobuf->length;
  93         rw = rw ? OBD_BRW_WRITE : OBD_BRW_READ;
  94
  95         for (i = 0, length = iobuf->length; length > 0;
  96              length -= pga[i].count, offset += pga[i].count, i++) { /*i last!*/
  97                 pga[i].pg = iobuf->maplist[i];
  98                 pga[i].off = offset;
  99                 /* To the end of the page, or the length, whatever is less */
 100                 pga[i].count = min_t(int, CFS_PAGE_SIZE - (offset & ~CFS_PAGE_MASK),
 101                                      length);
 102                 pga[i].flag = flags;
 103                 if (rw == OBD_BRW_READ)
 104                         POISON_PAGE(iobuf->maplist[i], 0x0d);
 105         }
 106
 107         ll_inode_fill_obdo(inode, rw, &oa);
 108
 109         if (rw == OBD_BRW_WRITE)
 110                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_WRITE, iobuf->length);
 111         else
 112                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_READ, iobuf->length);
 113         rc = obd_brw_rqset(rw, ll_i2obdexp(inode), &oa, lsm, iobuf->nr_pages,
 114                            pga, NULL);
 115         if ((rc > 0) && (rw == OBD_BRW_WRITE)) {
 116                 lov_stripe_lock(lsm);
 117                 obd_adjust_kms(ll_i2obdexp(inode), lsm, offset_orig + rc, 0);
 118                 lov_stripe_unlock(lsm);
 119         }
 120
 121         OBD_FREE(pga, sizeof(*pga) * iobuf->nr_pages);
 122         RETURN(rc);
 123 }
 124
 125 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 126 static int ll_max_readahead(struct inode *inode)
 127 {
 128         return 0;
 129 }
 130 #endif
 131
 132 struct address_space_operations ll_aops = {
 133         .readpage       = ll_readpage,
 134         .direct_IO      = ll_direct_IO_24,
 135         .writepage      = ll_writepage,
 136         .prepare_write  = ll_prepare_write,
 137         .commit_write   = ll_commit_write,
 138         .removepage     = ll_removepage,
 139         .sync_page      = NULL,
 140         .bmap           = NULL,
 141 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 142         .max_readahead  = ll_max_readahead,
 143 #endif
 144 };
 145