lustre/llite/rw24.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/llite/rw24.c
  37  *
  38  * Lustre Lite I/O page cache for the 2.4 kernel version
  39  */
  40
  41 #ifndef AUTOCONF_INCLUDED
  42 #include <linux/config.h>
  43 #endif
  44 #include <linux/kernel.h>
  45 #include <linux/mm.h>
  46 #include <linux/string.h>
  47 #include <linux/stat.h>
  48 #include <linux/errno.h>
  49 #include <linux/smp_lock.h>
  50 #include <linux/unistd.h>
  51 #include <linux/version.h>
  52 #include <asm/system.h>
  53 #include <asm/uaccess.h>
  54
  55 #include <linux/fs.h>
  56 #include <linux/iobuf.h>
  57 #include <linux/stat.h>
  58 #include <asm/uaccess.h>
  59 #include <linux/mm.h>
  60 #include <linux/pagemap.h>
  61 #include <linux/smp_lock.h>
  62
  63 #define DEBUG_SUBSYSTEM S_LLITE
  64
  65 #include <lustre_lite.h>
  66 #include "llite_internal.h"
  67 #include <linux/lustre_compat25.h>
  68
  69 static int ll_direct_IO_24(int rw,
  70 #ifdef HAVE_DIO_FILE
  71                            struct file *file,
  72 #else
  73                            struct inode *inode,
  74 #endif
  75                            struct kiobuf *iobuf, unsigned long blocknr,
  76                            int blocksize)
  77 {
  78 #ifdef HAVE_DIO_FILE
  79         struct inode *inode = file->f_dentry->d_inode;
  80 #endif
  81         struct ll_inode_info *lli = ll_i2info(inode);
  82         struct lov_stripe_md *lsm = lli->lli_smd;
  83         struct brw_page *pga;
  84         struct obdo oa;
  85         int length, i, flags, rc = 0;
  86         loff_t offset, offset_orig;
  87         ENTRY;
  88
  89         if (!lsm || !lsm->lsm_object_id)
  90                 RETURN(-EBADF);
  91
  92         offset = ((obd_off)blocknr << inode->i_blkbits);
  93         offset_orig = offset;
  94         CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size="LPSZ
  95                ", offset=%lld=%llx, pages %u\n",
  96                inode->i_ino, inode->i_generation, inode, iobuf->length,
  97                offset, offset, iobuf->nr_pages);
  98
  99         /* FIXME: io smaller than CFS_PAGE_SIZE is broken on ia64 */
 100         if ((iobuf->offset & (~CFS_PAGE_MASK)) ||
 101             (iobuf->length & (~CFS_PAGE_MASK)))
 102                 RETURN(-EINVAL);
 103
 104         OBD_ALLOC(pga, sizeof(*pga) * iobuf->nr_pages);
 105         if (!pga)
 106                 RETURN(-ENOMEM);
 107
 108         flags = 0 /* | OBD_BRW_DIRECTIO */;
 109         length = iobuf->length;
 110         rw = rw ? OBD_BRW_WRITE : OBD_BRW_READ;
 111
 112         for (i = 0, length = iobuf->length; length > 0;
 113              length -= pga[i].count, offset += pga[i].count, i++) { /*i last!*/
 114                 pga[i].pg = iobuf->maplist[i];
 115                 pga[i].off = offset;
 116                 /* To the end of the page, or the length, whatever is less */
 117                 pga[i].count = min_t(int, CFS_PAGE_SIZE - (offset & ~CFS_PAGE_MASK),
 118                                      length);
 119                 pga[i].flag = flags;
 120                 if (rw == OBD_BRW_READ)
 121                         POISON_PAGE(iobuf->maplist[i], 0x0d);
 122         }
 123
 124         ll_inode_fill_obdo(inode, rw, &oa);
 125
 126         if (rw == OBD_BRW_WRITE)
 127                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_WRITE, iobuf->length);
 128         else
 129                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_READ, iobuf->length);
 130         rc = obd_brw_rqset(rw, ll_i2obdexp(inode), &oa, lsm, iobuf->nr_pages,
 131                            pga, NULL);
 132         if ((rc > 0) && (rw == OBD_BRW_WRITE)) {
 133                 lov_stripe_lock(lsm);
 134                 obd_adjust_kms(ll_i2obdexp(inode), lsm, offset_orig + rc, 0);
 135                 lov_stripe_unlock(lsm);
 136         }
 137
 138         OBD_FREE(pga, sizeof(*pga) * iobuf->nr_pages);
 139         RETURN(rc);
 140 }
 141
 142 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 143 static int ll_max_readahead(struct inode *inode)
 144 {
 145         return 0;
 146 }
 147 #endif
 148
 149 struct address_space_operations ll_aops = {
 150         .readpage       = ll_readpage,
 151         .direct_IO      = ll_direct_IO_24,
 152         .writepage      = ll_writepage,
 153         .prepare_write  = ll_prepare_write,
 154         .commit_write   = ll_commit_write,
 155         .removepage     = ll_removepage,
 156         .sync_page      = NULL,
 157         .bmap           = NULL,
 158 #ifdef KERNEL_HAS_AS_MAX_READAHEAD
 159         .max_readahead  = ll_max_readahead,
 160 #endif
 161 };