Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes...
[pandora-kernel.git] / fs / btrfs / free-space-cache.c
index 0037427..11d2e9c 100644 (file)
@@ -24,6 +24,7 @@
 #include "free-space-cache.h"
 #include "transaction.h"
 #include "disk-io.h"
+#include "extent_io.h"
 
 #define BITS_PER_BITMAP                (PAGE_CACHE_SIZE * 8)
 #define MAX_CACHE_BYTES_PER_GIG        (32 * 1024)
@@ -81,6 +82,8 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root,
                return ERR_PTR(-ENOENT);
        }
 
+       inode->i_mapping->flags &= ~__GFP_FS;
+
        spin_lock(&block_group->lock);
        if (!root->fs_info->closing) {
                block_group->inode = igrab(inode);
@@ -222,6 +225,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
        u64 num_entries;
        u64 num_bitmaps;
        u64 generation;
+       u64 used = btrfs_block_group_used(&block_group->item);
        u32 cur_crc = ~(u32)0;
        pgoff_t index = 0;
        unsigned long first_page_offset;
@@ -467,6 +471,17 @@ next:
                index++;
        }
 
+       spin_lock(&block_group->tree_lock);
+       if (block_group->free_space != (block_group->key.offset - used -
+                                       block_group->bytes_super)) {
+               spin_unlock(&block_group->tree_lock);
+               printk(KERN_ERR "block group %llu has an wrong amount of free "
+                      "space\n", block_group->key.objectid);
+               ret = 0;
+               goto free_cache;
+       }
+       spin_unlock(&block_group->tree_lock);
+
        ret = 1;
 out:
        kfree(checksums);
@@ -493,18 +508,23 @@ int btrfs_write_out_cache(struct btrfs_root *root,
        struct inode *inode;
        struct rb_node *node;
        struct list_head *pos, *n;
+       struct page **pages;
        struct page *page;
        struct extent_state *cached_state = NULL;
+       struct btrfs_free_cluster *cluster = NULL;
+       struct extent_io_tree *unpin = NULL;
        struct list_head bitmap_list;
        struct btrfs_key key;
+       u64 start, end, len;
        u64 bytes = 0;
        u32 *crc, *checksums;
-       pgoff_t index = 0, last_index = 0;
        unsigned long first_page_offset;
-       int num_checksums;
+       int index = 0, num_pages = 0;
        int entries = 0;
        int bitmaps = 0;
        int ret = 0;
+       bool next_page = false;
+       bool out_of_space = false;
 
        root = root->fs_info->tree_root;
 
@@ -532,24 +552,43 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                return 0;
        }
 
-       last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
+       num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+               PAGE_CACHE_SHIFT;
        filemap_write_and_wait(inode->i_mapping);
        btrfs_wait_ordered_range(inode, inode->i_size &
                                 ~(root->sectorsize - 1), (u64)-1);
 
        /* We need a checksum per page. */
-       num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE;
-       crc = checksums  = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS);
+       crc = checksums = kzalloc(sizeof(u32) * num_pages, GFP_NOFS);
        if (!crc) {
                iput(inode);
                return 0;
        }
 
+       pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
+       if (!pages) {
+               kfree(crc);
+               iput(inode);
+               return 0;
+       }
+
        /* Since the first page has all of our checksums and our generation we
         * need to calculate the offset into the page that we can start writing
         * our entries.
         */
-       first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64);
+       first_page_offset = (sizeof(u32) * num_pages) + sizeof(u64);
+
+       /* Get the cluster for this block_group if it exists */
+       if (!list_empty(&block_group->cluster_list))
+               cluster = list_entry(block_group->cluster_list.next,
+                                    struct btrfs_free_cluster,
+                                    block_group_list);
+
+       /*
+        * We shouldn't have switched the pinned extents yet so this is the
+        * right one
+        */
+       unpin = root->fs_info->pinned_extents;
 
        /*
         * Lock all pages first so we can lock the extent safely.
@@ -559,20 +598,18 @@ int btrfs_write_out_cache(struct btrfs_root *root,
         * after find_get_page at this point.  Just putting this here so people
         * know and don't freak out.
         */
-       while (index <= last_index) {
+       while (index < num_pages) {
                page = grab_cache_page(inode->i_mapping, index);
                if (!page) {
-                       pgoff_t i = 0;
+                       int i;
 
-                       while (i < index) {
-                               page = find_get_page(inode->i_mapping, i);
-                               unlock_page(page);
-                               page_cache_release(page);
-                               page_cache_release(page);
-                               i++;
+                       for (i = 0; i < num_pages; i++) {
+                               unlock_page(pages[i]);
+                               page_cache_release(pages[i]);
                        }
                        goto out_free;
                }
+               pages[index] = page;
                index++;
        }
 
@@ -580,6 +617,12 @@ int btrfs_write_out_cache(struct btrfs_root *root,
        lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
                         0, &cached_state, GFP_NOFS);
 
+       /*
+        * When searching for pinned extents, we need to start at our start
+        * offset.
+        */
+       start = block_group->key.objectid;
+
        /* Write out the extent entries */
        do {
                struct btrfs_free_space_entry *entry;
@@ -587,18 +630,25 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                unsigned long offset = 0;
                unsigned long start_offset = 0;
 
+               next_page = false;
+
                if (index == 0) {
                        start_offset = first_page_offset;
                        offset = start_offset;
                }
 
-               page = find_get_page(inode->i_mapping, index);
+               if (index >= num_pages) {
+                       out_of_space = true;
+                       break;
+               }
+
+               page = pages[index];
 
                addr = kmap(page);
                entry = addr + start_offset;
 
                memset(addr, 0, PAGE_CACHE_SIZE);
-               while (1) {
+               while (node && !next_page) {
                        struct btrfs_free_space *e;
 
                        e = rb_entry(node, struct btrfs_free_space, offset_index);
@@ -614,12 +664,49 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                                entry->type = BTRFS_FREE_SPACE_EXTENT;
                        }
                        node = rb_next(node);
-                       if (!node)
-                               break;
+                       if (!node && cluster) {
+                               node = rb_first(&cluster->root);
+                               cluster = NULL;
+                       }
                        offset += sizeof(struct btrfs_free_space_entry);
                        if (offset + sizeof(struct btrfs_free_space_entry) >=
                            PAGE_CACHE_SIZE)
+                               next_page = true;
+                       entry++;
+               }
+
+               /*
+                * We want to add any pinned extents to our free space cache
+                * so we don't leak the space
+                */
+               while (!next_page && (start < block_group->key.objectid +
+                                     block_group->key.offset)) {
+                       ret = find_first_extent_bit(unpin, start, &start, &end,
+                                                   EXTENT_DIRTY);
+                       if (ret) {
+                               ret = 0;
                                break;
+                       }
+
+                       /* This pinned extent is out of our range */
+                       if (start >= block_group->key.objectid +
+                           block_group->key.offset)
+                               break;
+
+                       len = block_group->key.objectid +
+                               block_group->key.offset - start;
+                       len = min(len, end + 1 - start);
+
+                       entries++;
+                       entry->offset = cpu_to_le64(start);
+                       entry->bytes = cpu_to_le64(len);
+                       entry->type = BTRFS_FREE_SPACE_EXTENT;
+
+                       start = end + 1;
+                       offset += sizeof(struct btrfs_free_space_entry);
+                       if (offset + sizeof(struct btrfs_free_space_entry) >=
+                           PAGE_CACHE_SIZE)
+                               next_page = true;
                        entry++;
                }
                *crc = ~(u32)0;
@@ -632,25 +719,8 @@ int btrfs_write_out_cache(struct btrfs_root *root,
 
                bytes += PAGE_CACHE_SIZE;
 
-               ClearPageChecked(page);
-               set_page_extent_mapped(page);
-               SetPageUptodate(page);
-               set_page_dirty(page);
-
-               /*
-                * We need to release our reference we got for grab_cache_page,
-                * except for the first page which will hold our checksums, we
-                * do that below.
-                */
-               if (index != 0) {
-                       unlock_page(page);
-                       page_cache_release(page);
-               }
-
-               page_cache_release(page);
-
                index++;
-       } while (node);
+       } while (node || next_page);
 
        /* Write out the bitmaps */
        list_for_each_safe(pos, n, &bitmap_list) {
@@ -658,7 +728,11 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                struct btrfs_free_space *entry =
                        list_entry(pos, struct btrfs_free_space, list);
 
-               page = find_get_page(inode->i_mapping, index);
+               if (index >= num_pages) {
+                       out_of_space = true;
+                       break;
+               }
+               page = pages[index];
 
                addr = kmap(page);
                memcpy(addr, entry->bitmap, PAGE_CACHE_SIZE);
@@ -669,64 +743,58 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                crc++;
                bytes += PAGE_CACHE_SIZE;
 
-               ClearPageChecked(page);
-               set_page_extent_mapped(page);
-               SetPageUptodate(page);
-               set_page_dirty(page);
-               unlock_page(page);
-               page_cache_release(page);
-               page_cache_release(page);
                list_del_init(&entry->list);
                index++;
        }
 
+       if (out_of_space) {
+               btrfs_drop_pages(pages, num_pages);
+               unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+                                    i_size_read(inode) - 1, &cached_state,
+                                    GFP_NOFS);
+               ret = 0;
+               goto out_free;
+       }
+
        /* Zero out the rest of the pages just to make sure */
-       while (index <= last_index) {
+       while (index < num_pages) {
                void *addr;
 
-               page = find_get_page(inode->i_mapping, index);
-
+               page = pages[index];
                addr = kmap(page);
                memset(addr, 0, PAGE_CACHE_SIZE);
                kunmap(page);
-               ClearPageChecked(page);
-               set_page_extent_mapped(page);
-               SetPageUptodate(page);
-               set_page_dirty(page);
-               unlock_page(page);
-               page_cache_release(page);
-               page_cache_release(page);
                bytes += PAGE_CACHE_SIZE;
                index++;
        }
 
-       btrfs_set_extent_delalloc(inode, 0, bytes - 1, &cached_state);
-
        /* Write the checksums and trans id to the first page */
        {
                void *addr;
                u64 *gen;
 
-               page = find_get_page(inode->i_mapping, 0);
+               page = pages[0];
 
                addr = kmap(page);
-               memcpy(addr, checksums, sizeof(u32) * num_checksums);
-               gen = addr + (sizeof(u32) * num_checksums);
+               memcpy(addr, checksums, sizeof(u32) * num_pages);
+               gen = addr + (sizeof(u32) * num_pages);
                *gen = trans->transid;
                kunmap(page);
-               ClearPageChecked(page);
-               set_page_extent_mapped(page);
-               SetPageUptodate(page);
-               set_page_dirty(page);
-               unlock_page(page);
-               page_cache_release(page);
-               page_cache_release(page);
        }
-       BTRFS_I(inode)->generation = trans->transid;
 
+       ret = btrfs_dirty_pages(root, inode, pages, num_pages, 0,
+                                           bytes, &cached_state);
+       btrfs_drop_pages(pages, num_pages);
        unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
                             i_size_read(inode) - 1, &cached_state, GFP_NOFS);
 
+       if (ret) {
+               ret = 0;
+               goto out_free;
+       }
+
+       BTRFS_I(inode)->generation = trans->transid;
+
        filemap_write_and_wait(inode->i_mapping);
 
        key.objectid = BTRFS_FREE_SPACE_OBJECTID;
@@ -777,6 +845,7 @@ out_free:
                BTRFS_I(inode)->generation = 0;
        }
        kfree(checksums);
+       kfree(pages);
        btrfs_update_inode(trans, root, inode);
        iput(inode);
        return ret;