fs/btrfs/tests/extent-io-tests.c

   1 /*
   2  * Copyright (C) 2013 Fusion IO.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/pagemap.h>
  20 #include <linux/sched.h>
  21 #include <linux/sizes.h>
  22 #include "btrfs-tests.h"
  23 #include "../extent_io.h"
  24
  25 #define PROCESS_UNLOCK          (1 << 0)
  26 #define PROCESS_RELEASE         (1 << 1)
  27 #define PROCESS_TEST_LOCKED     (1 << 2)
  28
  29 static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
  30                                        unsigned long flags)
  31 {
  32         int ret;
  33         struct page *pages[16];
  34         unsigned long index = start >> PAGE_CACHE_SHIFT;
  35         unsigned long end_index = end >> PAGE_CACHE_SHIFT;
  36         unsigned long nr_pages = end_index - index + 1;
  37         int i;
  38         int count = 0;
  39         int loops = 0;
  40
  41         while (nr_pages > 0) {
  42                 ret = find_get_pages_contig(inode->i_mapping, index,
  43                                      min_t(unsigned long, nr_pages,
  44                                      ARRAY_SIZE(pages)), pages);
  45                 for (i = 0; i < ret; i++) {
  46                         if (flags & PROCESS_TEST_LOCKED &&
  47                             !PageLocked(pages[i]))
  48                                 count++;
  49                         if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
  50                                 unlock_page(pages[i]);
  51                         page_cache_release(pages[i]);
  52                         if (flags & PROCESS_RELEASE)
  53                                 page_cache_release(pages[i]);
  54                 }
  55                 nr_pages -= ret;
  56                 index += ret;
  57                 cond_resched();
  58                 loops++;
  59                 if (loops > 100000) {
  60                         printk(KERN_ERR "stuck in a loop, start %Lu, end %Lu, nr_pages %lu, ret %d\n", start, end, nr_pages, ret);
  61                         break;
  62                 }
  63         }
  64         return count;
  65 }
  66
  67 static int test_find_delalloc(void)
  68 {
  69         struct inode *inode;
  70         struct extent_io_tree tmp;
  71         struct page *page;
  72         struct page *locked_page = NULL;
  73         unsigned long index = 0;
  74         u64 total_dirty = SZ_256M;
  75         u64 max_bytes = SZ_128M;
  76         u64 start, end, test_start;
  77         u64 found;
  78         int ret = -EINVAL;
  79
  80         inode = btrfs_new_test_inode();
  81         if (!inode) {
  82                 test_msg("Failed to allocate test inode\n");
  83                 return -ENOMEM;
  84         }
  85
  86         extent_io_tree_init(&tmp, &inode->i_data);
  87
  88         /*
  89          * First go through and create and mark all of our pages dirty, we pin
  90          * everything to make sure our pages don't get evicted and screw up our
  91          * test.
  92          */
  93         for (index = 0; index < (total_dirty >> PAGE_CACHE_SHIFT); index++) {
  94                 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
  95                 if (!page) {
  96                         test_msg("Failed to allocate test page\n");
  97                         ret = -ENOMEM;
  98                         goto out;
  99                 }
 100                 SetPageDirty(page);
 101                 if (index) {
 102                         unlock_page(page);
 103                 } else {
 104                         page_cache_get(page);
 105                         locked_page = page;
 106                 }
 107         }
 108
 109         /* Test this scenario
 110          * |--- delalloc ---|
 111          * |---  search  ---|
 112          */
 113         set_extent_delalloc(&tmp, 0, 4095, NULL, GFP_NOFS);
 114         start = 0;
 115         end = 0;
 116         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 117                                          &end, max_bytes);
 118         if (!found) {
 119                 test_msg("Should have found at least one delalloc\n");
 120                 goto out_bits;
 121         }
 122         if (start != 0 || end != 4095) {
 123                 test_msg("Expected start 0 end 4095, got start %Lu end %Lu\n",
 124                          start, end);
 125                 goto out_bits;
 126         }
 127         unlock_extent(&tmp, start, end);
 128         unlock_page(locked_page);
 129         page_cache_release(locked_page);
 130
 131         /*
 132          * Test this scenario
 133          *
 134          * |--- delalloc ---|
 135          *           |--- search ---|
 136          */
 137         test_start = SZ_64M;
 138         locked_page = find_lock_page(inode->i_mapping,
 139                                      test_start >> PAGE_CACHE_SHIFT);
 140         if (!locked_page) {
 141                 test_msg("Couldn't find the locked page\n");
 142                 goto out_bits;
 143         }
 144         set_extent_delalloc(&tmp, 4096, max_bytes - 1, NULL, GFP_NOFS);
 145         start = test_start;
 146         end = 0;
 147         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 148                                          &end, max_bytes);
 149         if (!found) {
 150                 test_msg("Couldn't find delalloc in our range\n");
 151                 goto out_bits;
 152         }
 153         if (start != test_start || end != max_bytes - 1) {
 154                 test_msg("Expected start %Lu end %Lu, got start %Lu, end "
 155                          "%Lu\n", test_start, max_bytes - 1, start, end);
 156                 goto out_bits;
 157         }
 158         if (process_page_range(inode, start, end,
 159                                PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 160                 test_msg("There were unlocked pages in the range\n");
 161                 goto out_bits;
 162         }
 163         unlock_extent(&tmp, start, end);
 164         /* locked_page was unlocked above */
 165         page_cache_release(locked_page);
 166
 167         /*
 168          * Test this scenario
 169          * |--- delalloc ---|
 170          *                    |--- search ---|
 171          */
 172         test_start = max_bytes + 4096;
 173         locked_page = find_lock_page(inode->i_mapping, test_start >>
 174                                      PAGE_CACHE_SHIFT);
 175         if (!locked_page) {
 176                 test_msg("Could'nt find the locked page\n");
 177                 goto out_bits;
 178         }
 179         start = test_start;
 180         end = 0;
 181         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 182                                          &end, max_bytes);
 183         if (found) {
 184                 test_msg("Found range when we shouldn't have\n");
 185                 goto out_bits;
 186         }
 187         if (end != (u64)-1) {
 188                 test_msg("Did not return the proper end offset\n");
 189                 goto out_bits;
 190         }
 191
 192         /*
 193          * Test this scenario
 194          * [------- delalloc -------|
 195          * [max_bytes]|-- search--|
 196          *
 197          * We are re-using our test_start from above since it works out well.
 198          */
 199         set_extent_delalloc(&tmp, max_bytes, total_dirty - 1, NULL, GFP_NOFS);
 200         start = test_start;
 201         end = 0;
 202         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 203                                          &end, max_bytes);
 204         if (!found) {
 205                 test_msg("Didn't find our range\n");
 206                 goto out_bits;
 207         }
 208         if (start != test_start || end != total_dirty - 1) {
 209                 test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
 210                          test_start, total_dirty - 1, start, end);
 211                 goto out_bits;
 212         }
 213         if (process_page_range(inode, start, end,
 214                                PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 215                 test_msg("Pages in range were not all locked\n");
 216                 goto out_bits;
 217         }
 218         unlock_extent(&tmp, start, end);
 219
 220         /*
 221          * Now to test where we run into a page that is no longer dirty in the
 222          * range we want to find.
 223          */
 224         page = find_get_page(inode->i_mapping,
 225                              (max_bytes + SZ_1M) >> PAGE_CACHE_SHIFT);
 226         if (!page) {
 227                 test_msg("Couldn't find our page\n");
 228                 goto out_bits;
 229         }
 230         ClearPageDirty(page);
 231         page_cache_release(page);
 232
 233         /* We unlocked it in the previous test */
 234         lock_page(locked_page);
 235         start = test_start;
 236         end = 0;
 237         /*
 238          * Currently if we fail to find dirty pages in the delalloc range we
 239          * will adjust max_bytes down to PAGE_CACHE_SIZE and then re-search.  If
 240          * this changes at any point in the future we will need to fix this
 241          * tests expected behavior.
 242          */
 243         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 244                                          &end, max_bytes);
 245         if (!found) {
 246                 test_msg("Didn't find our range\n");
 247                 goto out_bits;
 248         }
 249         if (start != test_start && end != test_start + PAGE_CACHE_SIZE - 1) {
 250                 test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
 251                          test_start, test_start + PAGE_CACHE_SIZE - 1, start,
 252                          end);
 253                 goto out_bits;
 254         }
 255         if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
 256                                PROCESS_UNLOCK)) {
 257                 test_msg("Pages in range were not all locked\n");
 258                 goto out_bits;
 259         }
 260         ret = 0;
 261 out_bits:
 262         clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_NOFS);
 263 out:
 264         if (locked_page)
 265                 page_cache_release(locked_page);
 266         process_page_range(inode, 0, total_dirty - 1,
 267                            PROCESS_UNLOCK | PROCESS_RELEASE);
 268         iput(inode);
 269         return ret;
 270 }
 271
 272 int btrfs_test_extent_io(void)
 273 {
 274         test_msg("Running find delalloc tests\n");
 275         return test_find_delalloc();
 276 }