lustre/obdfilter/filter_san.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  linux/fs/obdfilter/filter_san.c
   5  *
   6  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   7  *   Author: Peter Braam <braam@clusterfs.com>
   8  *   Author: Andreas Dilger <adilger@clusterfs.com>
   9  *
  10  *   This file is part of Lustre, http://www.lustre.org.
  11  *
  12  *   Lustre is free software; you can redistribute it and/or
  13  *   modify it under the terms of version 2 of the GNU General Public
  14  *   License as published by the Free Software Foundation.
  15  *
  16  *   Lustre is distributed in the hope that it will be useful,
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *   GNU General Public License for more details.
  20  *
  21  *   You should have received a copy of the GNU General Public License
  22  *   along with Lustre; if not, write to the Free Software
  23  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #define DEBUG_SUBSYSTEM S_FILTER
  27
  28 #include <linux/config.h>
  29 #include <linux/module.h>
  30 #include <linux/pagemap.h> // XXX kill me soon
  31 #include <linux/version.h>
  32
  33 #include <linux/obd_class.h>
  34 #include <linux/lustre_fsfilt.h>
  35 #include "filter_internal.h"
  36
  37 /* sanobd setup methods - use a specific mount option */
  38 int filter_san_setup(struct obd_device *obd, obd_count len, void *buf)
  39 {
  40         struct obd_ioctl_data* data = buf;
  41         char *option = NULL;
  42
  43         if (!data->ioc_inlbuf2)
  44                 RETURN(-EINVAL);
  45
  46         /* for extN/ext3 filesystem, we must mount it with 'writeback' mode */
  47         if (!strcmp(data->ioc_inlbuf2, "extN"))
  48                 option = "data=writeback";
  49         else if (!strcmp(data->ioc_inlbuf2, "ext3"))
  50                 option = "data=writeback,asyncdel";
  51         else
  52                 LBUG(); /* just a reminder */
  53
  54         return filter_common_setup(obd, len, buf, option);
  55 }
  56
  57 int filter_san_preprw(int cmd, struct obd_export *exp, struct obdo *oa,
  58                       int objcount, struct obd_ioobj *obj, int niocount,
  59                       struct niobuf_remote *nb)
  60 {
  61         struct obd_ioobj *o = obj;
  62         struct niobuf_remote *rnb = nb;
  63         int rc = 0;
  64         int i;
  65         ENTRY;
  66         LASSERT(objcount == 1);
  67
  68         for (i = 0; i < objcount; i++, o++) {
  69                 struct dentry *dentry;
  70                 struct inode *inode;
  71 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
  72                 sector_t (*fs_bmap)(struct address_space *, sector_t);
  73 #else
  74                 int (*fs_bmap)(struct address_space *, long);
  75 #endif
  76                 int j;
  77
  78                 dentry = filter_oa2dentry(exp->exp_obd, oa);
  79                 if (IS_ERR(dentry))
  80                         GOTO(out, rc = PTR_ERR(dentry));
  81
  82                 inode = dentry->d_inode;
  83                 if (!inode) {
  84                         CERROR("trying to BRW to non-existent file "LPU64"\n",
  85                                o->ioo_id);
  86                         f_dput(dentry);
  87                         GOTO(out, rc = -ENOENT);
  88                 }
  89                 fs_bmap = inode->i_mapping->a_ops->bmap;
  90
  91                 for (j = 0; j < o->ioo_bufcnt; j++, rnb++) {
  92                         long block;
  93
  94                         block = rnb->offset >> inode->i_blkbits;
  95
  96                         if (cmd == OBD_BRW_READ) {
  97                                 block = fs_bmap(inode->i_mapping, block);
  98                         } else {
  99                                 loff_t newsize = rnb->offset + rnb->len;
 100                                 /* fs_prep_san_write will also update inode
 101                                  * size for us:
 102                                  * (1) new alloced block
 103                                  * (2) existed block but size extented
 104                                  */
 105                                 /* FIXME We could call fs_prep_san_write()
 106                                  * only once for all the blocks allocation.
 107                                  * Now call it once for each block, for
 108                                  * simplicity. And if error happens, we
 109                                  * probably need to release previous alloced
 110                                  * block */
 111                                 rc = fs_prep_san_write(exp->exp_obd, inode,
 112                                                        &block, 1, newsize);
 113                                 if (rc)
 114                                         break;
 115                         }
 116
 117                         rnb->offset = block;
 118                 }
 119                 f_dput(dentry);
 120         }
 121 out:
 122         RETURN(rc);
 123 }
 124