lustre/llite/rw26.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 routines for the 2.5/2.6 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 #ifndef AUTOCONF_INCLUDED
  25 #include <linux/config.h>
  26 #endif
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/unistd.h>
  34 #include <linux/version.h>
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37
  38 #include <linux/fs.h>
  39 #include <linux/buffer_head.h>
  40 #include <linux/mpage.h>
  41 #include <linux/writeback.h>
  42 #include <linux/stat.h>
  43 #include <asm/uaccess.h>
  44 #include <asm/segment.h>
  45 #include <linux/mm.h>
  46 #include <linux/pagemap.h>
  47 #include <linux/smp_lock.h>
  48
  49 #define DEBUG_SUBSYSTEM S_LLITE
  50
  51 //#include <lustre_mdc.h>
  52 #include <lustre_lite.h>
  53 #include "llite_internal.h"
  54 #include <linux/lustre_compat25.h>
  55
  56 static int ll_writepage_26(struct page *page, struct writeback_control *wbc)
  57 {
  58         return ll_writepage(page);
  59 }
  60
  61 /* It is safe to not check anything in invalidatepage/releasepage below
  62    because they are run with page locked and all our io is happening with
  63    locked page too */
  64 #ifdef HAVE_INVALIDATEPAGE_RETURN_INT
  65 static int ll_invalidatepage(struct page *page, unsigned long offset)
  66 {
  67         if (offset)
  68                 return 0;
  69         if (PagePrivate(page))
  70                 ll_removepage(page);
  71         return 1;
  72 }
  73 #else
  74 static void ll_invalidatepage(struct page *page, unsigned long offset)
  75 {
  76         if (offset == 0 && PagePrivate(page))
  77                 ll_removepage(page);
  78 }
  79 #endif
  80 static int ll_releasepage(struct page *page, gfp_t gfp_mask)
  81 {
  82         if (PagePrivate(page))
  83                 ll_removepage(page);
  84         return 1;
  85 }
  86
  87 static int ll_set_page_dirty(struct page *page)
  88 {
  89         struct ll_async_page *llap;
  90         ENTRY;
  91
  92         llap = llap_from_page(page, LLAP_ORIGIN_UNKNOWN);
  93         if (IS_ERR(llap))
  94                 RETURN(PTR_ERR(llap));
  95
  96         llap_write_pending(page->mapping->host, llap);
  97         RETURN(__set_page_dirty_nobuffers(page));
  98 }
  99
 100 #define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
 101
 102 static inline int ll_get_user_pages(int rw, unsigned long user_addr,
 103                                     size_t size, struct page ***pages)
 104 {
 105         int result = -ENOMEM;
 106         int page_count;
 107
 108         /* set an arbitrary limit to prevent arithmetic overflow */
 109         if (size > MAX_DIRECTIO_SIZE) {
 110                 *pages = NULL;
 111                 return -EFBIG;
 112         }
 113
 114         page_count = (user_addr + size + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
 115         page_count -= user_addr >> CFS_PAGE_SHIFT;
 116
 117         OBD_ALLOC_WAIT(*pages, page_count * sizeof(**pages));
 118         if (*pages) {
 119                 down_read(&current->mm->mmap_sem);
 120                 result = get_user_pages(current, current->mm, user_addr,
 121                                         page_count, (rw == READ), 0, *pages,
 122                                         NULL);
 123                 up_read(&current->mm->mmap_sem);
 124                 if (result < 0)
 125                         OBD_FREE(*pages, page_count * sizeof(**pages));
 126         }
 127
 128         return result;
 129 }
 130
 131 /*  ll_free_user_pages - tear down page struct array
 132  *  @pages: array of page struct pointers underlying target buffer */
 133 static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
 134 {
 135         int i;
 136
 137         for (i = 0; i < npages; i++) {
 138                 if (do_dirty)
 139                         set_page_dirty_lock(pages[i]);
 140                 page_cache_release(pages[i]);
 141         }
 142
 143         OBD_FREE(pages, npages * sizeof(*pages));
 144 }
 145
 146 static ssize_t ll_direct_IO_26_seg(int rw, struct inode *inode,
 147                                    struct address_space *mapping,
 148                                    struct lov_stripe_md *lsm,
 149                                    size_t size, loff_t file_offset,
 150                                    struct page **pages, int page_count)
 151 {
 152         struct brw_page *pga;
 153         struct obdo oa;
 154         int opc, i, rc = 0;
 155         size_t length;
 156         struct obd_capa *ocapa;
 157         loff_t file_offset_orig = file_offset;
 158         ENTRY;
 159
 160         OBD_ALLOC(pga, sizeof(*pga) * page_count);
 161         if (!pga) {
 162                 CDEBUG(D_VFSTRACE, "sizeof(*pga) = %u page_count = %u\n",
 163                        (int)sizeof(*pga), page_count);
 164                 RETURN(-ENOMEM);
 165         }
 166
 167         for (i = 0, length = size; length > 0;
 168              length -=pga[i].count, file_offset +=pga[i].count,i++) {/*i last!*/
 169                 pga[i].pg = pages[i];
 170                 pga[i].off = file_offset;
 171                 /* To the end of the page, or the length, whatever is less */
 172                 pga[i].count = min_t(int, CFS_PAGE_SIZE -
 173                                           (file_offset & ~CFS_PAGE_MASK),
 174                                      length);
 175                 pga[i].flag = 0;
 176                 if (rw == READ)
 177                         POISON_PAGE(pages[i], 0x0d);
 178         }
 179
 180         ll_inode_fill_obdo(inode, rw, &oa);
 181
 182         if (rw == WRITE) {
 183                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 184                                     LPROC_LL_DIRECT_WRITE, size);
 185                 opc = CAPA_OPC_OSS_WRITE;
 186                 llap_write_pending(inode, NULL);
 187         } else {
 188                 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
 189                                     LPROC_LL_DIRECT_READ, size);
 190                 opc = CAPA_OPC_OSS_RW;
 191         }
 192         ocapa = ll_osscapa_get(inode, current->fsuid, opc);
 193         rc = obd_brw_rqset(rw == WRITE ? OBD_BRW_WRITE : OBD_BRW_READ,
 194                            ll_i2dtexp(inode), &oa, lsm, page_count, pga, NULL,
 195                            ocapa);
 196         capa_put(ocapa);
 197         if ((rc > 0) && (rw == WRITE)) {
 198                 lov_stripe_lock(lsm);
 199                 obd_adjust_kms(ll_i2dtexp(inode), lsm, file_offset_orig + rc, 0);
 200                 lov_stripe_unlock(lsm);
 201         }
 202
 203         OBD_FREE(pga, sizeof(*pga) * page_count);
 204         RETURN(rc);
 205 }
 206
 207 /* This is the maximum size of a single O_DIRECT request, based on a 128kB
 208  * kmalloc limit.  We need to fit all of the brw_page structs, each one
 209  * representing PAGE_SIZE worth of user data, into a single buffer, and
 210  * then truncate this to be a full-sized RPC.  This is 22MB for 4kB pages. */
 211 #define MAX_DIO_SIZE ((128 * 1024 / sizeof(struct brw_page) * CFS_PAGE_SIZE) & \
 212                       ~(PTLRPC_MAX_BRW_SIZE - 1))
 213 static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
 214                                const struct iovec *iov, loff_t file_offset,
 215                                unsigned long nr_segs)
 216 {
 217         struct file *file = iocb->ki_filp;
 218         struct inode *inode = file->f_mapping->host;
 219         ssize_t count = iov_length(iov, nr_segs), tot_bytes = 0;
 220         struct ll_inode_info *lli = ll_i2info(inode);
 221         unsigned long seg = 0;
 222         size_t size = MAX_DIO_SIZE;
 223         ENTRY;
 224
 225         if (!lli->lli_smd || !lli->lli_smd->lsm_object_id)
 226                 RETURN(-EBADF);
 227
 228         /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
 229         if ((file_offset & ~CFS_PAGE_MASK) || (count & ~CFS_PAGE_MASK))
 230                 RETURN(-EINVAL);
 231
 232         CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size="LPSZ" (max %lu), "
 233                "offset=%lld=%llx, pages "LPSZ" (max %lu)\n",
 234                inode->i_ino, inode->i_generation, inode, count, MAX_DIO_SIZE,
 235                file_offset, file_offset, count >> CFS_PAGE_SHIFT,
 236                MAX_DIO_SIZE >> CFS_PAGE_SHIFT);
 237
 238         if (rw == WRITE)
 239                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_WRITE, count);
 240         else
 241                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_READ, count);
 242
 243         /* Check that all user buffers are aligned as well */
 244         for (seg = 0; seg < nr_segs; seg++) {
 245                 if (((unsigned long)iov[seg].iov_base & ~CFS_PAGE_MASK) ||
 246                     (iov[seg].iov_len & ~CFS_PAGE_MASK))
 247                         RETURN(-EINVAL);
 248         }
 249
 250         for (seg = 0; seg < nr_segs; seg++) {
 251                 size_t iov_left = iov[seg].iov_len;
 252                 unsigned long user_addr = (unsigned long)iov[seg].iov_base;
 253
 254                 while (iov_left > 0) {
 255                         struct page **pages;
 256                         int page_count;
 257                         ssize_t result;
 258
 259                         page_count = ll_get_user_pages(rw, user_addr,
 260                                                        min(size, iov_left),
 261                                                        &pages);
 262                         LASSERT(page_count != 0);
 263                         if (page_count > 0) {
 264                                 result = ll_direct_IO_26_seg(rw, inode,
 265                                                              file->f_mapping,
 266                                                              lli->lli_smd,
 267                                                              min(size,iov_left),
 268                                                              file_offset, pages,
 269                                                              page_count);
 270                                 ll_free_user_pages(pages, page_count, rw==READ);
 271                         } else {
 272                                 result = 0;
 273                         }
 274                         if (page_count < 0 || result <= 0) {
 275                                 /* If we can't allocate a large enough buffer
 276                                  * for the request, shrink it to a smaller
 277                                  * PAGE_SIZE multiple and try again.
 278                                  * We should always be able to kmalloc for a
 279                                  * page worth of page pointers = 4MB on i386. */
 280                                 if ((page_count == -ENOMEM||result == -ENOMEM)&&
 281                                     size > (CFS_PAGE_SIZE / sizeof(*pages)) *
 282                                            CFS_PAGE_SIZE) {
 283                                         size = ((((size / 2) - 1) |
 284                                                  ~CFS_PAGE_MASK) + 1) &
 285                                                 CFS_PAGE_MASK;
 286                                         CDEBUG(D_VFSTRACE, "DIO size now %u\n",
 287                                                (int)size);
 288                                         continue;
 289                                 }
 290
 291                                 if (tot_bytes > 0)
 292                                         RETURN(tot_bytes);
 293                                 RETURN(page_count < 0 ? page_count : result);
 294                         }
 295
 296                         tot_bytes += result;
 297                         file_offset += result;
 298                         iov_left -= result;
 299                         user_addr += result;
 300                 }
 301         }
 302         RETURN(tot_bytes);
 303 }
 304
 305 struct address_space_operations ll_aops = {
 306         .readpage       = ll_readpage,
 307 //        .readpages      = ll_readpages,
 308         .direct_IO      = ll_direct_IO_26,
 309         .writepage      = ll_writepage_26,
 310         .writepages     = generic_writepages,
 311         .set_page_dirty = ll_set_page_dirty,
 312         .sync_page      = NULL,
 313         .prepare_write  = ll_prepare_write,
 314         .commit_write   = ll_commit_write,
 315         .invalidatepage = ll_invalidatepage,
 316         .releasepage    = ll_releasepage,
 317         .bmap           = NULL
 318 };