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 "btrfs-tests.h"
  22 #include "../extent_io.h"
  23
  24 #define PROCESS_UNLOCK          (1 << 0)
  25 #define PROCESS_RELEASE         (1 << 1)
  26 #define PROCESS_TEST_LOCKED     (1 << 2)
  27
  28 static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
  29                                        unsigned long flags)
  30 {
  31         int ret;
  32         struct page *pages[16];
  33         unsigned long index = start >> PAGE_CACHE_SHIFT;
  34         unsigned long end_index = end >> PAGE_CACHE_SHIFT;
  35         unsigned long nr_pages = end_index - index + 1;
  36         int i;
  37         int count = 0;
  38         int loops = 0;
  39
  40         while (nr_pages > 0) {
  41                 ret = find_get_pages_contig(inode->i_mapping, index,
  42                                      min_t(unsigned long, nr_pages,
  43                                      ARRAY_SIZE(pages)), pages);
  44                 for (i = 0; i < ret; i++) {
  45                         if (flags & PROCESS_TEST_LOCKED &&
  46                             !PageLocked(pages[i]))
  47                                 count++;
  48                         if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
  49                                 unlock_page(pages[i]);
  50                         page_cache_release(pages[i]);
  51                         if (flags & PROCESS_RELEASE)
  52                                 page_cache_release(pages[i]);
  53                 }
  54                 nr_pages -= ret;
  55                 index += ret;
  56                 cond_resched();
  57                 loops++;
  58                 if (loops > 100000) {
  59                         printk(KERN_ERR "stuck in a loop, start %Lu, end %Lu, nr_pages %lu, ret %d\n", start, end, nr_pages, ret);
  60                         break;
  61                 }
  62         }
  63         return count;
  64 }
  65
  66 static int test_find_delalloc(void)
  67 {
  68         struct inode *inode;
  69         struct extent_io_tree tmp;
  70         struct page *page;
  71         struct page *locked_page = NULL;
  72         unsigned long index = 0;
  73         u64 total_dirty = 256 * 1024 * 1024;
  74         u64 max_bytes = 128 * 1024 * 1024;
  75         u64 start, end, test_start;
  76         u64 found;
  77         int ret = -EINVAL;
  78
  79         inode = btrfs_new_test_inode();
  80         if (!inode) {
  81                 test_msg("Failed to allocate test inode\n");
  82                 return -ENOMEM;
  83         }
  84
  85         extent_io_tree_init(&tmp, &inode->i_data);
  86
  87         /*
  88          * First go through and create and mark all of our pages dirty, we pin
  89          * everything to make sure our pages don't get evicted and screw up our
  90          * test.
  91          */
  92         for (index = 0; index < (total_dirty >> PAGE_CACHE_SHIFT); index++) {
  93                 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
  94                 if (!page) {
  95                         test_msg("Failed to allocate test page\n");
  96                         ret = -ENOMEM;
  97                         goto out;
  98                 }
  99                 SetPageDirty(page);
 100                 if (index) {
 101                         unlock_page(page);
 102                 } else {
 103                         page_cache_get(page);
 104                         locked_page = page;
 105                 }
 106         }
 107
 108         /* Test this scenario
 109          * |--- delalloc ---|
 110          * |---  search  ---|
 111          */
 112         set_extent_delalloc(&tmp, 0, 4095, NULL, GFP_NOFS);
 113         start = 0;
 114         end = 0;
 115         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 116                                          &end, max_bytes);
 117         if (!found) {
 118                 test_msg("Should have found at least one delalloc\n");
 119                 goto out_bits;
 120         }
 121         if (start != 0 || end != 4095) {
 122                 test_msg("Expected start 0 end 4095, got start %Lu end %Lu\n",
 123                          start, end);
 124                 goto out_bits;
 125         }
 126         unlock_extent(&tmp, start, end);
 127         unlock_page(locked_page);
 128         page_cache_release(locked_page);
 129
 130         /*
 131          * Test this scenario
 132          *
 133          * |--- delalloc ---|
 134          *           |--- search ---|
 135          */
 136         test_start = 64 * 1024 * 1024;
 137         locked_page = find_lock_page(inode->i_mapping,
 138                                      test_start >> PAGE_CACHE_SHIFT);
 139         if (!locked_page) {
 140                 test_msg("Couldn't find the locked page\n");
 141                 goto out_bits;
 142         }
 143         set_extent_delalloc(&tmp, 4096, max_bytes - 1, NULL, GFP_NOFS);
 144         start = test_start;
 145         end = 0;
 146         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 147                                          &end, max_bytes);
 148         if (!found) {
 149                 test_msg("Couldn't find delalloc in our range\n");
 150                 goto out_bits;
 151         }
 152         if (start != test_start || end != max_bytes - 1) {
 153                 test_msg("Expected start %Lu end %Lu, got start %Lu, end "
 154                          "%Lu\n", test_start, max_bytes - 1, start, end);
 155                 goto out_bits;
 156         }
 157         if (process_page_range(inode, start, end,
 158                                PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 159                 test_msg("There were unlocked pages in the range\n");
 160                 goto out_bits;
 161         }
 162         unlock_extent(&tmp, start, end);
 163         /* locked_page was unlocked above */
 164         page_cache_release(locked_page);
 165
 166         /*
 167          * Test this scenario
 168          * |--- delalloc ---|
 169          *                    |--- search ---|
 170          */
 171         test_start = max_bytes + 4096;
 172         locked_page = find_lock_page(inode->i_mapping, test_start >>
 173                                      PAGE_CACHE_SHIFT);
 174         if (!locked_page) {
 175                 test_msg("Could'nt find the locked page\n");
 176                 goto out_bits;
 177         }
 178         start = test_start;
 179         end = 0;
 180         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 181                                          &end, max_bytes);
 182         if (found) {
 183                 test_msg("Found range when we shouldn't have\n");
 184                 goto out_bits;
 185         }
 186         if (end != (u64)-1) {
 187                 test_msg("Did not return the proper end offset\n");
 188                 goto out_bits;
 189         }
 190
 191         /*
 192          * Test this scenario
 193          * [------- delalloc -------|
 194          * [max_bytes]|-- search--|
 195          *
 196          * We are re-using our test_start from above since it works out well.
 197          */
 198         set_extent_delalloc(&tmp, max_bytes, total_dirty - 1, NULL, GFP_NOFS);
 199         start = test_start;
 200         end = 0;
 201         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 202                                          &end, max_bytes);
 203         if (!found) {
 204                 test_msg("Didn't find our range\n");
 205                 goto out_bits;
 206         }
 207         if (start != test_start || end != total_dirty - 1) {
 208                 test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
 209                          test_start, total_dirty - 1, start, end);
 210                 goto out_bits;
 211         }
 212         if (process_page_range(inode, start, end,
 213                                PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 214                 test_msg("Pages in range were not all locked\n");
 215                 goto out_bits;
 216         }
 217         unlock_extent(&tmp, start, end);
 218
 219         /*
 220          * Now to test where we run into a page that is no longer dirty in the
 221          * range we want to find.
 222          */
 223         page = find_get_page(inode->i_mapping, (max_bytes + (1 * 1024 * 1024))
 224                              >> PAGE_CACHE_SHIFT);
 225         if (!page) {
 226                 test_msg("Couldn't find our page\n");
 227                 goto out_bits;
 228         }
 229         ClearPageDirty(page);
 230         page_cache_release(page);
 231
 232         /* We unlocked it in the previous test */
 233         lock_page(locked_page);
 234         start = test_start;
 235         end = 0;
 236         /*
 237          * Currently if we fail to find dirty pages in the delalloc range we
 238          * will adjust max_bytes down to PAGE_CACHE_SIZE and then re-search.  If
 239          * this changes at any point in the future we will need to fix this
 240          * tests expected behavior.
 241          */
 242         found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
 243                                          &end, max_bytes);
 244         if (!found) {
 245                 test_msg("Didn't find our range\n");
 246                 goto out_bits;
 247         }
 248         if (start != test_start && end != test_start + PAGE_CACHE_SIZE - 1) {
 249                 test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
 250                          test_start, test_start + PAGE_CACHE_SIZE - 1, start,
 251                          end);
 252                 goto out_bits;
 253         }
 254         if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
 255                                PROCESS_UNLOCK)) {
 256                 test_msg("Pages in range were not all locked\n");
 257                 goto out_bits;
 258         }
 259         ret = 0;
 260 out_bits:
 261         clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_NOFS);
 262 out:
 263         if (locked_page)
 264                 page_cache_release(locked_page);
 265         process_page_range(inode, 0, total_dirty - 1,
 266                            PROCESS_UNLOCK | PROCESS_RELEASE);
 267         iput(inode);
 268         return ret;
 269 }
 270
 271 int btrfs_test_extent_io(void)
 272 {
 273         test_msg("Running find delalloc tests\n");
 274         return test_find_delalloc();
 275 }