Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / btrfs / tests / extent-io-tests.c
diff --git a/kernel/fs/btrfs/tests/extent-io-tests.c b/kernel/fs/btrfs/tests/extent-io-tests.c
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+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include "btrfs-tests.h"
+#include "../extent_io.h"
+
+#define PROCESS_UNLOCK         (1 << 0)
+#define PROCESS_RELEASE                (1 << 1)
+#define PROCESS_TEST_LOCKED    (1 << 2)
+
+static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
+                                      unsigned long flags)
+{
+       int ret;
+       struct page *pages[16];
+       unsigned long index = start >> PAGE_CACHE_SHIFT;
+       unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+       unsigned long nr_pages = end_index - index + 1;
+       int i;
+       int count = 0;
+       int loops = 0;
+
+       while (nr_pages > 0) {
+               ret = find_get_pages_contig(inode->i_mapping, index,
+                                    min_t(unsigned long, nr_pages,
+                                    ARRAY_SIZE(pages)), pages);
+               for (i = 0; i < ret; i++) {
+                       if (flags & PROCESS_TEST_LOCKED &&
+                           !PageLocked(pages[i]))
+                               count++;
+                       if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
+                               unlock_page(pages[i]);
+                       page_cache_release(pages[i]);
+                       if (flags & PROCESS_RELEASE)
+                               page_cache_release(pages[i]);
+               }
+               nr_pages -= ret;
+               index += ret;
+               cond_resched();
+               loops++;
+               if (loops > 100000) {
+                       printk(KERN_ERR "stuck in a loop, start %Lu, end %Lu, nr_pages %lu, ret %d\n", start, end, nr_pages, ret);
+                       break;
+               }
+       }
+       return count;
+}
+
+static int test_find_delalloc(void)
+{
+       struct inode *inode;
+       struct extent_io_tree tmp;
+       struct page *page;
+       struct page *locked_page = NULL;
+       unsigned long index = 0;
+       u64 total_dirty = 256 * 1024 * 1024;
+       u64 max_bytes = 128 * 1024 * 1024;
+       u64 start, end, test_start;
+       u64 found;
+       int ret = -EINVAL;
+
+       inode = btrfs_new_test_inode();
+       if (!inode) {
+               test_msg("Failed to allocate test inode\n");
+               return -ENOMEM;
+       }
+
+       extent_io_tree_init(&tmp, &inode->i_data);
+
+       /*
+        * First go through and create and mark all of our pages dirty, we pin
+        * everything to make sure our pages don't get evicted and screw up our
+        * test.
+        */
+       for (index = 0; index < (total_dirty >> PAGE_CACHE_SHIFT); index++) {
+               page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+               if (!page) {
+                       test_msg("Failed to allocate test page\n");
+                       ret = -ENOMEM;
+                       goto out;
+               }
+               SetPageDirty(page);
+               if (index) {
+                       unlock_page(page);
+               } else {
+                       page_cache_get(page);
+                       locked_page = page;
+               }
+       }
+
+       /* Test this scenario
+        * |--- delalloc ---|
+        * |---  search  ---|
+        */
+       set_extent_delalloc(&tmp, 0, 4095, NULL, GFP_NOFS);
+       start = 0;
+       end = 0;
+       found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
+                                        &end, max_bytes);
+       if (!found) {
+               test_msg("Should have found at least one delalloc\n");
+               goto out_bits;
+       }
+       if (start != 0 || end != 4095) {
+               test_msg("Expected start 0 end 4095, got start %Lu end %Lu\n",
+                        start, end);
+               goto out_bits;
+       }
+       unlock_extent(&tmp, start, end);
+       unlock_page(locked_page);
+       page_cache_release(locked_page);
+
+       /*
+        * Test this scenario
+        *
+        * |--- delalloc ---|
+        *           |--- search ---|
+        */
+       test_start = 64 * 1024 * 1024;
+       locked_page = find_lock_page(inode->i_mapping,
+                                    test_start >> PAGE_CACHE_SHIFT);
+       if (!locked_page) {
+               test_msg("Couldn't find the locked page\n");
+               goto out_bits;
+       }
+       set_extent_delalloc(&tmp, 4096, max_bytes - 1, NULL, GFP_NOFS);
+       start = test_start;
+       end = 0;
+       found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
+                                        &end, max_bytes);
+       if (!found) {
+               test_msg("Couldn't find delalloc in our range\n");
+               goto out_bits;
+       }
+       if (start != test_start || end != max_bytes - 1) {
+               test_msg("Expected start %Lu end %Lu, got start %Lu, end "
+                        "%Lu\n", test_start, max_bytes - 1, start, end);
+               goto out_bits;
+       }
+       if (process_page_range(inode, start, end,
+                              PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
+               test_msg("There were unlocked pages in the range\n");
+               goto out_bits;
+       }
+       unlock_extent(&tmp, start, end);
+       /* locked_page was unlocked above */
+       page_cache_release(locked_page);
+
+       /*
+        * Test this scenario
+        * |--- delalloc ---|
+        *                    |--- search ---|
+        */
+       test_start = max_bytes + 4096;
+       locked_page = find_lock_page(inode->i_mapping, test_start >>
+                                    PAGE_CACHE_SHIFT);
+       if (!locked_page) {
+               test_msg("Could'nt find the locked page\n");
+               goto out_bits;
+       }
+       start = test_start;
+       end = 0;
+       found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
+                                        &end, max_bytes);
+       if (found) {
+               test_msg("Found range when we shouldn't have\n");
+               goto out_bits;
+       }
+       if (end != (u64)-1) {
+               test_msg("Did not return the proper end offset\n");
+               goto out_bits;
+       }
+
+       /*
+        * Test this scenario
+        * [------- delalloc -------|
+        * [max_bytes]|-- search--|
+        *
+        * We are re-using our test_start from above since it works out well.
+        */
+       set_extent_delalloc(&tmp, max_bytes, total_dirty - 1, NULL, GFP_NOFS);
+       start = test_start;
+       end = 0;
+       found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
+                                        &end, max_bytes);
+       if (!found) {
+               test_msg("Didn't find our range\n");
+               goto out_bits;
+       }
+       if (start != test_start || end != total_dirty - 1) {
+               test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
+                        test_start, total_dirty - 1, start, end);
+               goto out_bits;
+       }
+       if (process_page_range(inode, start, end,
+                              PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
+               test_msg("Pages in range were not all locked\n");
+               goto out_bits;
+       }
+       unlock_extent(&tmp, start, end);
+
+       /*
+        * Now to test where we run into a page that is no longer dirty in the
+        * range we want to find.
+        */
+       page = find_get_page(inode->i_mapping, (max_bytes + (1 * 1024 * 1024))
+                            >> PAGE_CACHE_SHIFT);
+       if (!page) {
+               test_msg("Couldn't find our page\n");
+               goto out_bits;
+       }
+       ClearPageDirty(page);
+       page_cache_release(page);
+
+       /* We unlocked it in the previous test */
+       lock_page(locked_page);
+       start = test_start;
+       end = 0;
+       /*
+        * Currently if we fail to find dirty pages in the delalloc range we
+        * will adjust max_bytes down to PAGE_CACHE_SIZE and then re-search.  If
+        * this changes at any point in the future we will need to fix this
+        * tests expected behavior.
+        */
+       found = find_lock_delalloc_range(inode, &tmp, locked_page, &start,
+                                        &end, max_bytes);
+       if (!found) {
+               test_msg("Didn't find our range\n");
+               goto out_bits;
+       }
+       if (start != test_start && end != test_start + PAGE_CACHE_SIZE - 1) {
+               test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
+                        test_start, test_start + PAGE_CACHE_SIZE - 1, start,
+                        end);
+               goto out_bits;
+       }
+       if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
+                              PROCESS_UNLOCK)) {
+               test_msg("Pages in range were not all locked\n");
+               goto out_bits;
+       }
+       ret = 0;
+out_bits:
+       clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_NOFS);
+out:
+       if (locked_page)
+               page_cache_release(locked_page);
+       process_page_range(inode, 0, total_dirty - 1,
+                          PROCESS_UNLOCK | PROCESS_RELEASE);
+       iput(inode);
+       return ret;
+}
+
+int btrfs_test_extent_io(void)
+{
+       test_msg("Running find delalloc tests\n");
+       return test_find_delalloc();
+}