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 <linux/lustre_mdc.h>
  48 #include <linux/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 ptlrpc_request_set *set;
  68         struct obdo oa;
  69         int length, i, flags, rc = 0;
  70         loff_t offset;
  71         ENTRY;
  72
  73         if (!lsm || !lsm->lsm_object_id)
  74                 RETURN(-EBADF);
  75
  76         /* FIXME: io smaller than PAGE_SIZE is broken on ia64 */
  77         if ((iobuf->offset & (PAGE_SIZE - 1)) ||
  78             (iobuf->length & (PAGE_SIZE - 1)))
  79                 RETURN(-EINVAL);
  80
  81         set = ptlrpc_prep_set();
  82         if (set == NULL)
  83                 RETURN(-ENOMEM);
  84
  85         OBD_ALLOC(pga, sizeof(*pga) * iobuf->nr_pages);
  86         if (!pga) {
  87                 ptlrpc_set_destroy(set);
  88                 RETURN(-ENOMEM);
  89         }
  90
  91         flags = 0 /* | OBD_BRW_DIRECTIO */;
  92         offset = ((obd_off)blocknr << inode->i_blkbits);
  93         length = iobuf->length;
  94         rw = rw ? OBD_BRW_WRITE : OBD_BRW_READ;
  95
  96         for (i = 0, length = iobuf->length; length > 0;
  97              length -= pga[i].count, offset += pga[i].count, i++) { /*i last!*/
  98                 pga[i].pg = iobuf->maplist[i];
  99                 pga[i].off = offset;
 100                 /* To the end of the page, or the length, whatever is less */
 101                 pga[i].count = min_t(int, PAGE_SIZE - (offset & ~PAGE_MASK),
 102                                      length);
 103                 pga[i].flag = flags;
 104                 if (rw == OBD_BRW_READ)
 105                         POISON_PAGE(iobuf->maplist[i], 0x0d);
 106         }
 107
 108         ll_inode_fill_obdo(inode, rw, &oa);
 109
 110         if (rw == OBD_BRW_WRITE)
 111                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 112                                     LPROC_LL_DIRECT_WRITE, iobuf->length);
 113         else
 114                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 115                                     LPROC_LL_DIRECT_READ, iobuf->length);
 116         rc = obd_brw_async(rw, ll_i2obdexp(inode), &oa, lsm, iobuf->nr_pages,
 117                            pga, set, NULL);
 118         if (rc) {
 119                 CDEBUG(rc == -ENOSPC ? D_INODE : D_ERROR,
 120                        "error from obd_brw_async: rc = %d\n", rc);
 121         } else {
 122                 rc = ptlrpc_set_wait(set);
 123                 if (rc)
 124                         CERROR("error from callback: rc = %d\n", rc);
 125         }
 126         ptlrpc_set_destroy(set);
 127         if (rc == 0) {
 128                 rc = iobuf->length;
 129                 if (rw == OBD_BRW_WRITE) {
 130                         lov_stripe_lock(lsm);
 131                         obd_adjust_kms(ll_i2obdexp(inode), lsm, offset, 0);
 132                         lov_stripe_unlock(lsm);
 133                 }
 134         }
 135
 136         OBD_FREE(pga, sizeof(*pga) * iobuf->nr_pages);
 137         RETURN(rc);
 138 }
 139
 140 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 141 static int ll_max_readahead(struct inode *inode)
 142 {
 143         return 0;
 144 }
 145 #endif
 146
 147 struct address_space_operations ll_aops = {
 148         .readpage       = ll_readpage,
 149         .direct_IO      = ll_direct_IO_24,
 150         .writepage      = ll_writepage,
 151         .prepare_write  = ll_prepare_write,
 152         .commit_write   = ll_commit_write,
 153         .removepage     = ll_removepage,
 154         .sync_page      = NULL,
 155         .bmap           = NULL,
 156 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 157         .max_readahead  = ll_max_readahead,
 158 #endif
 159 };