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_mds.h>
  48 #include <linux/lustre_lite.h>
  49 #include "llite_internal.h"
  50 #include <linux/lustre_compat25.h>
  51
  52 static int ll_writepage_24(struct page *page)
  53 {
  54         struct inode *inode = page->mapping->host;
  55         struct obd_export *exp;
  56         struct ll_async_page *llap;
  57         int rc = 0;
  58         ENTRY;
  59
  60         LASSERT(!PageDirty(page));
  61         LASSERT(PageLocked(page));
  62
  63         exp = ll_i2obdexp(inode);
  64         if (exp == NULL)
  65                 GOTO(out, rc = -EINVAL);
  66
  67         llap = llap_from_page(page);
  68         if (IS_ERR(llap))
  69                 GOTO(out, rc = PTR_ERR(llap));
  70
  71         page_cache_get(page);
  72         if (llap->llap_write_queued) {
  73                 LL_CDEBUG_PAGE(D_PAGE, page, "marking urgent\n");
  74                 rc = obd_set_async_flags(exp, ll_i2info(inode)->lli_smd, NULL,
  75                                          llap->llap_cookie,
  76                                          ASYNC_READY | ASYNC_URGENT);
  77         } else {
  78                 llap->llap_write_queued = 1;
  79                 rc = obd_queue_async_io(exp, ll_i2info(inode)->lli_smd, NULL,
  80                                         llap->llap_cookie, OBD_BRW_WRITE, 0, 0,
  81                                         0, ASYNC_READY | ASYNC_URGENT);
  82                 if (rc == 0)
  83                         LL_CDEBUG_PAGE(D_PAGE, page, "mmap write queued\n");
  84                 else
  85                         llap->llap_write_queued = 0;
  86         }
  87         if (rc)
  88                 page_cache_release(page);
  89 out:
  90         if (rc)
  91                 unlock_page(page);
  92         RETURN(rc);
  93 }
  94
  95 static int ll_direct_IO_24(int rw,
  96 #ifdef HAVE_DIO_FILE
  97                            struct file *file,
  98 #else
  99                            struct inode *inode,
 100 #endif
 101                            struct kiobuf *iobuf, unsigned long blocknr,
 102                            int blocksize)
 103 {
 104 #ifdef HAVE_DIO_FILE
 105         struct inode *inode = file->f_dentry->d_inode;
 106 #endif
 107         struct ll_inode_info *lli = ll_i2info(inode);
 108         struct lov_stripe_md *lsm = lli->lli_smd;
 109         struct brw_page *pga;
 110         struct ptlrpc_request_set *set;
 111         struct obdo oa;
 112         int length, i, flags, rc = 0;
 113         loff_t offset;
 114         ENTRY;
 115
 116         if (!lsm || !lsm->lsm_object_id)
 117                 RETURN(-EBADF);
 118
 119         /* FIXME: io smaller than PAGE_SIZE is broken on ia64 */
 120         if ((iobuf->offset & (PAGE_SIZE - 1)) ||
 121             (iobuf->length & (PAGE_SIZE - 1)))
 122                 RETURN(-EINVAL);
 123
 124         set = ptlrpc_prep_set();
 125         if (set == NULL)
 126                 RETURN(-ENOMEM);
 127
 128         OBD_ALLOC(pga, sizeof(*pga) * iobuf->nr_pages);
 129         if (!pga) {
 130                 ptlrpc_set_destroy(set);
 131                 RETURN(-ENOMEM);
 132         }
 133
 134         flags = 0 /* | OBD_BRW_DIRECTIO */;
 135         offset = ((obd_off)blocknr << inode->i_blkbits);
 136         length = iobuf->length;
 137
 138         for (i = 0, length = iobuf->length; length > 0;
 139              length -= pga[i].count, offset += pga[i].count, i++) { /*i last!*/
 140                 pga[i].pg = iobuf->maplist[i];
 141                 pga[i].off = offset;
 142                 /* To the end of the page, or the length, whatever is less */
 143                 pga[i].count = min_t(int, PAGE_SIZE - (offset & ~PAGE_MASK),
 144                                      length);
 145                 pga[i].flag = flags;
 146                 if (rw == READ)
 147                         POISON_PAGE(iobuf->maplist[i], 0x0d);
 148         }
 149
 150         ll_inode_fill_obdo(inode, rw, &oa);
 151
 152         if (rw == WRITE)
 153                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 154                                     LPROC_LL_DIRECT_WRITE, iobuf->length);
 155         else
 156                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 157                                     LPROC_LL_DIRECT_READ, iobuf->length);
 158         rc = obd_brw_async(rw == WRITE ? OBD_BRW_WRITE : OBD_BRW_READ,
 159                            ll_i2obdexp(inode), &oa, lsm, iobuf->nr_pages, pga,
 160                            set, NULL);
 161         if (rc) {
 162                 CDEBUG(rc == -ENOSPC ? D_INODE : D_ERROR,
 163                        "error from obd_brw_async: rc = %d\n", rc);
 164         } else {
 165                 rc = ptlrpc_set_wait(set);
 166                 if (rc)
 167                         CERROR("error from callback: rc = %d\n", rc);
 168         }
 169         ptlrpc_set_destroy(set);
 170         if (rc == 0) {
 171                 rc = iobuf->length;
 172                 obdo_to_inode(inode, &oa, OBD_MD_FLBLOCKS);
 173         }
 174
 175         OBD_FREE(pga, sizeof(*pga) * iobuf->nr_pages);
 176         RETURN(rc);
 177 }
 178
 179 struct address_space_operations ll_aops = {
 180         readpage: ll_readpage,
 181         direct_IO: ll_direct_IO_24,
 182         writepage: ll_writepage_24,
 183         prepare_write: ll_prepare_write,
 184         commit_write: ll_commit_write,
 185         removepage: ll_removepage,
 186         sync_page: NULL,
 187         bmap: NULL
 188 };