const: constify remaining file_operations
[safe/jmp/linux-2.6] / fs / btrfs / file.c
index 84ecf3a..9ed17db 100644 (file)
 #include <linux/time.h>
 #include <linux/init.h>
 #include <linux/string.h>
-#include <linux/smp_lock.h>
 #include <linux/backing-dev.h>
 #include <linux/mpage.h>
 #include <linux/swap.h>
 #include <linux/writeback.h>
 #include <linux/statfs.h>
 #include <linux/compat.h>
-#include <linux/version.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
 #include "compat.h"
 
 
-static int noinline btrfs_copy_from_user(loff_t pos, int num_pages,
+/* simple helper to fault in pages and copy.  This should go away
+ * and be replaced with calls into generic code.
+ */
+static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
                                         int write_bytes,
                                         struct page **prepared_pages,
-                                        const char __user * buf)
+                                        const char __user *buf)
 {
        long page_fault = 0;
        int i;
@@ -72,12 +73,19 @@ static int noinline btrfs_copy_from_user(loff_t pos, int num_pages,
        return page_fault ? -EFAULT : 0;
 }
 
-static void noinline btrfs_drop_pages(struct page **pages, size_t num_pages)
+/*
+ * unlocks pages after btrfs_file_write is done with them
+ */
+static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages)
 {
        size_t i;
        for (i = 0; i < num_pages; i++) {
                if (!pages[i])
                        break;
+               /* page checked is some magic around finding pages that
+                * have been modified without going through btrfs_set_page_dirty
+                * clear it here
+                */
                ClearPageChecked(pages[i]);
                unlock_page(pages[i]);
                mark_page_accessed(pages[i]);
@@ -85,150 +93,15 @@ static void noinline btrfs_drop_pages(struct page **pages, size_t num_pages)
        }
 }
 
-static int noinline insert_inline_extent(struct btrfs_trans_handle *trans,
-                               struct btrfs_root *root, struct inode *inode,
-                               u64 offset, size_t size,
-                               struct page **pages, size_t page_offset,
-                               int num_pages)
-{
-       struct btrfs_key key;
-       struct btrfs_path *path;
-       struct extent_buffer *leaf;
-       char *kaddr;
-       unsigned long ptr;
-       struct btrfs_file_extent_item *ei;
-       struct page *page;
-       u32 datasize;
-       int err = 0;
-       int ret;
-       int i;
-       ssize_t cur_size;
-
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
-
-       btrfs_set_trans_block_group(trans, inode);
-
-       key.objectid = inode->i_ino;
-       key.offset = offset;
-       btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
-
-       ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
-       if (ret < 0) {
-               err = ret;
-               goto fail;
-       }
-       if (ret == 1) {
-               struct btrfs_key found_key;
-
-               if (path->slots[0] == 0)
-                       goto insert;
-
-               path->slots[0]--;
-               leaf = path->nodes[0];
-               btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-
-               if (found_key.objectid != inode->i_ino)
-                       goto insert;
-
-               if (found_key.type != BTRFS_EXTENT_DATA_KEY)
-                       goto insert;
-               ei = btrfs_item_ptr(leaf, path->slots[0],
-                                   struct btrfs_file_extent_item);
-
-               if (btrfs_file_extent_type(leaf, ei) !=
-                   BTRFS_FILE_EXTENT_INLINE) {
-                       goto insert;
-               }
-               btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-               ret = 0;
-       }
-       if (ret == 0) {
-               u32 found_size;
-               u64 found_end;
-
-               leaf = path->nodes[0];
-               ei = btrfs_item_ptr(leaf, path->slots[0],
-                                   struct btrfs_file_extent_item);
-
-               if (btrfs_file_extent_type(leaf, ei) !=
-                   BTRFS_FILE_EXTENT_INLINE) {
-                       err = ret;
-                       btrfs_print_leaf(root, leaf);
-                       printk("found wasn't inline offset %Lu inode %lu\n",
-                              offset, inode->i_ino);
-                       goto fail;
-               }
-               found_size = btrfs_file_extent_inline_len(leaf,
-                                         btrfs_item_nr(leaf, path->slots[0]));
-               found_end = key.offset + found_size;
-
-               if (found_end < offset + size) {
-                       btrfs_release_path(root, path);
-                       ret = btrfs_search_slot(trans, root, &key, path,
-                                               offset + size - found_end, 1);
-                       BUG_ON(ret != 0);
-
-                       ret = btrfs_extend_item(trans, root, path,
-                                               offset + size - found_end);
-                       if (ret) {
-                               err = ret;
-                               goto fail;
-                       }
-                       leaf = path->nodes[0];
-                       ei = btrfs_item_ptr(leaf, path->slots[0],
-                                           struct btrfs_file_extent_item);
-                       inode->i_blocks += (offset + size - found_end) >> 9;
-               }
-               if (found_end < offset) {
-                       ptr = btrfs_file_extent_inline_start(ei) + found_size;
-                       memset_extent_buffer(leaf, 0, ptr, offset - found_end);
-               }
-       } else {
-insert:
-               btrfs_release_path(root, path);
-               datasize = offset + size - key.offset;
-               inode->i_blocks += datasize >> 9;
-               datasize = btrfs_file_extent_calc_inline_size(datasize);
-               ret = btrfs_insert_empty_item(trans, root, path, &key,
-                                             datasize);
-               if (ret) {
-                       err = ret;
-                       printk("got bad ret %d\n", ret);
-                       goto fail;
-               }
-               leaf = path->nodes[0];
-               ei = btrfs_item_ptr(leaf, path->slots[0],
-                                   struct btrfs_file_extent_item);
-               btrfs_set_file_extent_generation(leaf, ei, trans->transid);
-               btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
-       }
-       ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
-
-       cur_size = size;
-       i = 0;
-       while (size > 0) {
-               page = pages[i];
-               kaddr = kmap_atomic(page, KM_USER0);
-               cur_size = min_t(size_t, PAGE_CACHE_SIZE - page_offset, size);
-               write_extent_buffer(leaf, kaddr + page_offset, ptr, cur_size);
-               kunmap_atomic(kaddr, KM_USER0);
-               page_offset = 0;
-               ptr += cur_size;
-               size -= cur_size;
-               if (i >= num_pages) {
-                       printk("i %d num_pages %d\n", i, num_pages);
-               }
-               i++;
-       }
-       btrfs_mark_buffer_dirty(leaf);
-fail:
-       btrfs_free_path(path);
-       return err;
-}
-
-static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
+/*
+ * after copy_from_user, pages need to be dirtied and we need to make
+ * sure holes are created between the current EOF and the start of
+ * any next extents (if required).
+ *
+ * this also makes the decision about creating an inline extent vs
+ * doing real data extents, marking pages dirty and delalloc as required.
+ */
+static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                                   struct btrfs_root *root,
                                   struct file *file,
                                   struct page **pages,
@@ -239,14 +112,10 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
        int err = 0;
        int i;
        struct inode *inode = fdentry(file)->d_inode;
-       struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
-       u64 hint_byte;
        u64 num_bytes;
        u64 start_pos;
        u64 end_of_last_block;
        u64 end_pos = pos + write_bytes;
-       u64 inline_size;
-       int did_inline = 0;
        loff_t isize = i_size_read(inode);
 
        start_pos = pos & ~((u64)root->sectorsize - 1);
@@ -254,115 +123,29 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
                    root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
 
        end_of_last_block = start_pos + num_bytes - 1;
-
-       lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
-       trans = btrfs_join_transaction(root, 1);
-       if (!trans) {
-               err = -ENOMEM;
-               goto out_unlock;
-       }
-       btrfs_set_trans_block_group(trans, inode);
-       hint_byte = 0;
-
-       if ((end_of_last_block & 4095) == 0) {
-               printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
-       }
-       set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS);
-
-       /* FIXME...EIEIO, ENOSPC and more */
-       /* insert any holes we need to create */
-       if (isize < start_pos) {
-               u64 last_pos_in_file;
-               u64 hole_size;
-               u64 mask = root->sectorsize - 1;
-               last_pos_in_file = (isize + mask) & ~mask;
-               hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
-               if (hole_size > 0) {
-                       btrfs_wait_ordered_range(inode, last_pos_in_file,
-                                                last_pos_in_file + hole_size);
-                       mutex_lock(&BTRFS_I(inode)->extent_mutex);
-                       err = btrfs_drop_extents(trans, root, inode,
-                                                last_pos_in_file,
-                                                last_pos_in_file + hole_size,
-                                                last_pos_in_file,
-                                                &hint_byte);
-                       if (err)
-                               goto failed;
-
-                       err = btrfs_insert_file_extent(trans, root,
-                                                      inode->i_ino,
-                                                      last_pos_in_file,
-                                                      0, 0, hole_size, 0);
-                       btrfs_drop_extent_cache(inode, last_pos_in_file,
-                                       last_pos_in_file + hole_size -1);
-                       mutex_unlock(&BTRFS_I(inode)->extent_mutex);
-                       btrfs_check_file(root, inode);
-               }
-               if (err)
-                       goto failed;
-       }
-
-       /*
-        * either allocate an extent for the new bytes or setup the key
-        * to show we are doing inline data in the extent
-        */
-       inline_size = end_pos;
-       if (isize >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
-           inline_size > root->fs_info->max_inline ||
-           (inline_size & (root->sectorsize -1)) == 0 ||
-           inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
-               /* check for reserved extents on each page, we don't want
-                * to reset the delalloc bit on things that already have
-                * extents reserved.
-                */
-               btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block);
-               for (i = 0; i < num_pages; i++) {
-                       struct page *p = pages[i];
-                       SetPageUptodate(p);
-                       ClearPageChecked(p);
-                       set_page_dirty(p);
-               }
-       } else {
-               u64 aligned_end;
-               /* step one, delete the existing extents in this range */
-               aligned_end = (pos + write_bytes + root->sectorsize - 1) &
-                       ~((u64)root->sectorsize - 1);
-               mutex_lock(&BTRFS_I(inode)->extent_mutex);
-               err = btrfs_drop_extents(trans, root, inode, start_pos,
-                                        aligned_end, aligned_end, &hint_byte);
-               if (err)
-                       goto failed;
-               if (isize > inline_size)
-                       inline_size = min_t(u64, isize, aligned_end);
-               inline_size -= start_pos;
-               err = insert_inline_extent(trans, root, inode, start_pos,
-                                          inline_size, pages, 0, num_pages);
-               btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
-               BUG_ON(err);
-               mutex_unlock(&BTRFS_I(inode)->extent_mutex);
-
-               /*
-                * an ugly way to do all the prop accounting around
-                * the page bits and mapping tags
-                */
-               set_page_writeback(pages[0]);
-               end_page_writeback(pages[0]);
-               did_inline = 1;
+       btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block);
+       for (i = 0; i < num_pages; i++) {
+               struct page *p = pages[i];
+               SetPageUptodate(p);
+               ClearPageChecked(p);
+               set_page_dirty(p);
        }
        if (end_pos > isize) {
                i_size_write(inode, end_pos);
-               if (did_inline)
-                       BTRFS_I(inode)->disk_i_size = end_pos;
-               btrfs_update_inode(trans, root, inode);
+               /* we've only changed i_size in ram, and we haven't updated
+                * the disk i_size.  There is no need to log the inode
+                * at this time.
+                */
        }
-failed:
-       err = btrfs_end_transaction(trans, root);
-out_unlock:
-       unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
        return err;
 }
 
-int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
+/*
+ * this drops all the extents in the cache that intersect the range
+ * [start, end].  Existing extents are split as required.
+ */
+int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
+                           int skip_pinned)
 {
        struct extent_map *em;
        struct extent_map *split = NULL;
@@ -371,24 +154,45 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
        u64 len = end - start + 1;
        int ret;
        int testend = 1;
+       unsigned long flags;
+       int compressed = 0;
 
        WARN_ON(end < start);
        if (end == (u64)-1) {
                len = (u64)-1;
                testend = 0;
        }
-       while(1) {
+       while (1) {
                if (!split)
                        split = alloc_extent_map(GFP_NOFS);
                if (!split2)
                        split2 = alloc_extent_map(GFP_NOFS);
 
-               spin_lock(&em_tree->lock);
+               write_lock(&em_tree->lock);
                em = lookup_extent_mapping(em_tree, start, len);
                if (!em) {
-                       spin_unlock(&em_tree->lock);
+                       write_unlock(&em_tree->lock);
                        break;
                }
+               flags = em->flags;
+               if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
+                       if (em->start <= start &&
+                           (!testend || em->start + em->len >= start + len)) {
+                               free_extent_map(em);
+                               write_unlock(&em_tree->lock);
+                               break;
+                       }
+                       if (start < em->start) {
+                               len = em->start - start;
+                       } else {
+                               len = start + len - (em->start + em->len);
+                               start = em->start + em->len;
+                       }
+                       free_extent_map(em);
+                       write_unlock(&em_tree->lock);
+                       continue;
+               }
+               compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
                clear_bit(EXTENT_FLAG_PINNED, &em->flags);
                remove_extent_mapping(em_tree, em);
 
@@ -396,9 +200,16 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
                    em->start < start) {
                        split->start = em->start;
                        split->len = start - em->start;
+                       split->orig_start = em->orig_start;
                        split->block_start = em->block_start;
+
+                       if (compressed)
+                               split->block_len = em->block_len;
+                       else
+                               split->block_len = split->len;
+
                        split->bdev = em->bdev;
-                       split->flags = em->flags;
+                       split->flags = flags;
                        ret = add_extent_mapping(em_tree, split);
                        BUG_ON(ret);
                        free_extent_map(split);
@@ -412,16 +223,24 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
                        split->start = start + len;
                        split->len = em->start + em->len - (start + len);
                        split->bdev = em->bdev;
-                       split->flags = em->flags;
+                       split->flags = flags;
 
-                       split->block_start = em->block_start + diff;
+                       if (compressed) {
+                               split->block_len = em->block_len;
+                               split->block_start = em->block_start;
+                               split->orig_start = em->orig_start;
+                       } else {
+                               split->block_len = split->len;
+                               split->block_start = em->block_start + diff;
+                               split->orig_start = split->start;
+                       }
 
                        ret = add_extent_mapping(em_tree, split);
                        BUG_ON(ret);
                        free_extent_map(split);
                        split = NULL;
                }
-               spin_unlock(&em_tree->lock);
+               write_unlock(&em_tree->lock);
 
                /* once for us */
                free_extent_map(em);
@@ -435,80 +254,6 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
        return 0;
 }
 
-int btrfs_check_file(struct btrfs_root *root, struct inode *inode)
-{
-       return 0;
-#if 0
-       struct btrfs_path *path;
-       struct btrfs_key found_key;
-       struct extent_buffer *leaf;
-       struct btrfs_file_extent_item *extent;
-       u64 last_offset = 0;
-       int nritems;
-       int slot;
-       int found_type;
-       int ret;
-       int err = 0;
-       u64 extent_end = 0;
-
-       path = btrfs_alloc_path();
-       ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino,
-                                      last_offset, 0);
-       while(1) {
-               nritems = btrfs_header_nritems(path->nodes[0]);
-               if (path->slots[0] >= nritems) {
-                       ret = btrfs_next_leaf(root, path);
-                       if (ret)
-                               goto out;
-                       nritems = btrfs_header_nritems(path->nodes[0]);
-               }
-               slot = path->slots[0];
-               leaf = path->nodes[0];
-               btrfs_item_key_to_cpu(leaf, &found_key, slot);
-               if (found_key.objectid != inode->i_ino)
-                       break;
-               if (found_key.type != BTRFS_EXTENT_DATA_KEY)
-                       goto out;
-
-               if (found_key.offset < last_offset) {
-                       WARN_ON(1);
-                       btrfs_print_leaf(root, leaf);
-                       printk("inode %lu found offset %Lu expected %Lu\n",
-                              inode->i_ino, found_key.offset, last_offset);
-                       err = 1;
-                       goto out;
-               }
-               extent = btrfs_item_ptr(leaf, slot,
-                                       struct btrfs_file_extent_item);
-               found_type = btrfs_file_extent_type(leaf, extent);
-               if (found_type == BTRFS_FILE_EXTENT_REG) {
-                       extent_end = found_key.offset +
-                            btrfs_file_extent_num_bytes(leaf, extent);
-               } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
-                       struct btrfs_item *item;
-                       item = btrfs_item_nr(leaf, slot);
-                       extent_end = found_key.offset +
-                            btrfs_file_extent_inline_len(leaf, item);
-                       extent_end = (extent_end + root->sectorsize - 1) &
-                               ~((u64)root->sectorsize -1 );
-               }
-               last_offset = extent_end;
-               path->slots[0]++;
-       }
-       if (0 && last_offset < inode->i_size) {
-               WARN_ON(1);
-               btrfs_print_leaf(root, leaf);
-               printk("inode %lu found offset %Lu size %Lu\n", inode->i_ino,
-                      last_offset, inode->i_size);
-               err = 1;
-
-       }
-out:
-       btrfs_free_path(path);
-       return err;
-#endif
-}
-
 /*
  * this is very complex, but the basic idea is to drop all extents
  * in the range start - end.  hint_block is filled in with a block number
@@ -517,13 +262,23 @@ out:
  * If an extent intersects the range but is not entirely inside the range
  * it is either truncated or split.  Anything entirely inside the range
  * is deleted from the tree.
+ *
+ * inline_limit is used to tell this code which offsets in the file to keep
+ * if they contain inline extents.
  */
-int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans,
+noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, struct inode *inode,
-                      u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
+                      u64 start, u64 end, u64 locked_end,
+                      u64 inline_limit, u64 *hint_byte, int drop_cache)
 {
        u64 extent_end = 0;
        u64 search_start = start;
+       u64 ram_bytes = 0;
+       u64 disk_bytenr = 0;
+       u64 orig_locked_end = locked_end;
+       u8 compression;
+       u8 encryption;
+       u16 other_encoding = 0;
        struct extent_buffer *leaf;
        struct btrfs_file_extent_item *extent;
        struct btrfs_path *path;
@@ -532,18 +287,20 @@ int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans,
        int keep;
        int slot;
        int bookend;
-       int found_type;
+       int found_type = 0;
        int found_extent;
        int found_inline;
        int recow;
        int ret;
 
-       btrfs_drop_extent_cache(inode, start, end - 1);
+       inline_limit = 0;
+       if (drop_cache)
+               btrfs_drop_extent_cache(inode, start, end - 1, 0);
 
        path = btrfs_alloc_path();
        if (!path)
                return -ENOMEM;
-       while(1) {
+       while (1) {
                recow = 0;
                btrfs_release_path(root, path);
                ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
@@ -562,6 +319,8 @@ next_slot:
                bookend = 0;
                found_extent = 0;
                found_inline = 0;
+               compression = 0;
+               encryption = 0;
                extent = NULL;
                leaf = path->nodes[0];
                slot = path->slots[0];
@@ -576,14 +335,21 @@ next_slot:
                        goto out;
                }
                if (recow) {
-                       search_start = key.offset;
+                       search_start = max(key.offset, start);
                        continue;
                }
                if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
                        extent = btrfs_item_ptr(leaf, slot,
                                                struct btrfs_file_extent_item);
                        found_type = btrfs_file_extent_type(leaf, extent);
-                       if (found_type == BTRFS_FILE_EXTENT_REG) {
+                       compression = btrfs_file_extent_compression(leaf,
+                                                                   extent);
+                       encryption = btrfs_file_extent_encryption(leaf,
+                                                                 extent);
+                       other_encoding = btrfs_file_extent_other_encoding(leaf,
+                                                                 extent);
+                       if (found_type == BTRFS_FILE_EXTENT_REG ||
+                           found_type == BTRFS_FILE_EXTENT_PREALLOC) {
                                extent_end =
                                     btrfs_file_extent_disk_bytenr(leaf,
                                                                   extent);
@@ -592,13 +358,13 @@ next_slot:
 
                                extent_end = key.offset +
                                     btrfs_file_extent_num_bytes(leaf, extent);
+                               ram_bytes = btrfs_file_extent_ram_bytes(leaf,
+                                                               extent);
                                found_extent = 1;
                        } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
-                               struct btrfs_item *item;
-                               item = btrfs_item_nr(leaf, slot);
                                found_inline = 1;
                                extent_end = key.offset +
-                                    btrfs_file_extent_inline_len(leaf, item);
+                                    btrfs_file_extent_inline_len(leaf, extent);
                        }
                } else {
                        extent_end = search_start;
@@ -621,38 +387,53 @@ next_slot:
                        goto next_slot;
                }
 
-               if (found_inline) {
-                       u64 mask = root->sectorsize - 1;
-                       search_start = (extent_end + mask) & ~mask;
-               } else
-                       search_start = extent_end;
-               if (end <= extent_end && start >= key.offset && found_inline) {
+               if (end <= extent_end && start >= key.offset && found_inline)
                        *hint_byte = EXTENT_MAP_INLINE;
-                       continue;
+
+               if (found_extent) {
+                       read_extent_buffer(leaf, &old, (unsigned long)extent,
+                                          sizeof(old));
                }
+
                if (end < extent_end && end >= key.offset) {
-                       if (found_extent) {
-                               u64 disk_bytenr =
-                                   btrfs_file_extent_disk_bytenr(leaf, extent);
-                               u64 disk_num_bytes =
-                                   btrfs_file_extent_disk_num_bytes(leaf,
-                                                                     extent);
-                               read_extent_buffer(leaf, &old,
-                                                  (unsigned long)extent,
-                                                  sizeof(old));
-                               if (disk_bytenr != 0) {
-                                       ret = btrfs_inc_extent_ref(trans, root,
-                                                disk_bytenr, disk_num_bytes,
-                                                root->root_key.objectid,
-                                                trans->transid,
-                                                key.objectid, end);
-                                       BUG_ON(ret);
-                               }
-                       }
                        bookend = 1;
                        if (found_inline && start <= key.offset)
                                keep = 1;
                }
+
+               if (bookend && found_extent) {
+                       if (locked_end < extent_end) {
+                               ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
+                                               locked_end, extent_end - 1,
+                                               GFP_NOFS);
+                               if (!ret) {
+                                       btrfs_release_path(root, path);
+                                       lock_extent(&BTRFS_I(inode)->io_tree,
+                                               locked_end, extent_end - 1,
+                                               GFP_NOFS);
+                                       locked_end = extent_end;
+                                       continue;
+                               }
+                               locked_end = extent_end;
+                       }
+                       disk_bytenr = le64_to_cpu(old.disk_bytenr);
+                       if (disk_bytenr != 0) {
+                               ret = btrfs_inc_extent_ref(trans, root,
+                                          disk_bytenr,
+                                          le64_to_cpu(old.disk_num_bytes), 0,
+                                          root->root_key.objectid,
+                                          key.objectid, key.offset -
+                                          le64_to_cpu(old.offset));
+                               BUG_ON(ret);
+                       }
+               }
+
+               if (found_inline) {
+                       u64 mask = root->sectorsize - 1;
+                       search_start = (extent_end + mask) & ~mask;
+               } else
+                       search_start = extent_end;
+
                /* truncate existing extent */
                if (start > key.offset) {
                        u64 new_num;
@@ -668,10 +449,11 @@ next_slot:
                                                                      extent);
                                if (btrfs_file_extent_disk_bytenr(leaf,
                                                                  extent)) {
-                                       dec_i_blocks(inode, old_num - new_num);
+                                       inode_sub_bytes(inode, old_num -
+                                                       new_num);
                                }
-                               btrfs_set_file_extent_num_bytes(leaf, extent,
-                                                               new_num);
+                               btrfs_set_file_extent_num_bytes(leaf,
+                                                       extent, new_num);
                                btrfs_mark_buffer_dirty(leaf);
                        } else if (key.offset < inline_limit &&
                                   (end > extent_end) &&
@@ -679,65 +461,39 @@ next_slot:
                                u32 new_size;
                                new_size = btrfs_file_extent_calc_inline_size(
                                                   inline_limit - key.offset);
-                               dec_i_blocks(inode, (extent_end - key.offset) -
-                                       (inline_limit - key.offset));
-                               btrfs_truncate_item(trans, root, path,
-                                                   new_size, 1);
+                               inode_sub_bytes(inode, extent_end -
+                                               inline_limit);
+                               btrfs_set_file_extent_ram_bytes(leaf, extent,
+                                                       new_size);
+                               if (!compression && !encryption) {
+                                       btrfs_truncate_item(trans, root, path,
+                                                           new_size, 1);
+                               }
                        }
                }
                /* delete the entire extent */
                if (!keep) {
-                       u64 disk_bytenr = 0;
-                       u64 disk_num_bytes = 0;
-                       u64 extent_num_bytes = 0;
-                       u64 root_gen;
-                       u64 root_owner;
-
-                       root_gen = btrfs_header_generation(leaf);
-                       root_owner = btrfs_header_owner(leaf);
-                       if (found_extent) {
-                               disk_bytenr =
-                                     btrfs_file_extent_disk_bytenr(leaf,
-                                                                    extent);
-                               disk_num_bytes =
-                                     btrfs_file_extent_disk_num_bytes(leaf,
-                                                                      extent);
-                               extent_num_bytes =
-                                     btrfs_file_extent_num_bytes(leaf, extent);
-                               *hint_byte =
-                                       btrfs_file_extent_disk_bytenr(leaf,
-                                                                     extent);
-                       }
+                       if (found_inline)
+                               inode_sub_bytes(inode, extent_end -
+                                               key.offset);
                        ret = btrfs_del_item(trans, root, path);
                        /* TODO update progress marker and return */
                        BUG_ON(ret);
-                       btrfs_release_path(root, path);
                        extent = NULL;
-                       if (found_extent && disk_bytenr != 0) {
-                               dec_i_blocks(inode, extent_num_bytes);
-                               ret = btrfs_free_extent(trans, root,
-                                               disk_bytenr,
-                                               disk_num_bytes,
-                                               root_owner,
-                                               root_gen, inode->i_ino,
-                                               key.offset, 0);
-                       }
-
-                       BUG_ON(ret);
-                       if (!bookend && search_start >= end) {
-                               ret = 0;
-                               goto out;
-                       }
-                       if (!bookend)
-                               continue;
+                       btrfs_release_path(root, path);
+                       /* the extent will be freed later */
                }
                if (bookend && found_inline && start <= key.offset) {
                        u32 new_size;
                        new_size = btrfs_file_extent_calc_inline_size(
                                                   extent_end - end);
-                       dec_i_blocks(inode, (extent_end - key.offset) -
-                                       (extent_end - end));
-                       btrfs_truncate_item(trans, root, path, new_size, 0);
+                       inode_sub_bytes(inode, end - key.offset);
+                       btrfs_set_file_extent_ram_bytes(leaf, extent,
+                                                       new_size);
+                       if (!compression && !encryption)
+                               ret = btrfs_truncate_item(trans, root, path,
+                                                         new_size, 0);
+                       BUG_ON(ret);
                }
                /* create bookend, splitting the extent in two */
                if (bookend && found_extent) {
@@ -745,50 +501,326 @@ next_slot:
                        ins.objectid = inode->i_ino;
                        ins.offset = end;
                        btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
+
                        btrfs_release_path(root, path);
+                       path->leave_spinning = 1;
                        ret = btrfs_insert_empty_item(trans, root, path, &ins,
                                                      sizeof(*extent));
+                       BUG_ON(ret);
 
                        leaf = path->nodes[0];
-                       if (ret) {
-                               btrfs_print_leaf(root, leaf);
-                               printk("got %d on inserting %Lu %u %Lu start %Lu end %Lu found %Lu %Lu keep was %d\n", ret , ins.objectid, ins.type, ins.offset, start, end, key.offset, extent_end, keep);
-                       }
-                       BUG_ON(ret);
                        extent = btrfs_item_ptr(leaf, path->slots[0],
                                                struct btrfs_file_extent_item);
                        write_extent_buffer(leaf, &old,
                                            (unsigned long)extent, sizeof(old));
 
+                       btrfs_set_file_extent_compression(leaf, extent,
+                                                         compression);
+                       btrfs_set_file_extent_encryption(leaf, extent,
+                                                        encryption);
+                       btrfs_set_file_extent_other_encoding(leaf, extent,
+                                                            other_encoding);
                        btrfs_set_file_extent_offset(leaf, extent,
                                    le64_to_cpu(old.offset) + end - key.offset);
                        WARN_ON(le64_to_cpu(old.num_bytes) <
                                (extent_end - end));
                        btrfs_set_file_extent_num_bytes(leaf, extent,
                                                        extent_end - end);
-                       btrfs_set_file_extent_type(leaf, extent,
-                                                  BTRFS_FILE_EXTENT_REG);
 
+                       /*
+                        * set the ram bytes to the size of the full extent
+                        * before splitting.  This is a worst case flag,
+                        * but its the best we can do because we don't know
+                        * how splitting affects compression
+                        */
+                       btrfs_set_file_extent_ram_bytes(leaf, extent,
+                                                       ram_bytes);
+                       btrfs_set_file_extent_type(leaf, extent, found_type);
+
+                       btrfs_unlock_up_safe(path, 1);
                        btrfs_mark_buffer_dirty(path->nodes[0]);
-                       if (le64_to_cpu(old.disk_bytenr) != 0) {
-                               inode->i_blocks +=
-                                     btrfs_file_extent_num_bytes(leaf,
-                                                                 extent) >> 9;
+                       btrfs_set_lock_blocking(path->nodes[0]);
+
+                       path->leave_spinning = 0;
+                       btrfs_release_path(root, path);
+                       if (disk_bytenr != 0)
+                               inode_add_bytes(inode, extent_end - end);
+               }
+
+               if (found_extent && !keep) {
+                       u64 old_disk_bytenr = le64_to_cpu(old.disk_bytenr);
+
+                       if (old_disk_bytenr != 0) {
+                               inode_sub_bytes(inode,
+                                               le64_to_cpu(old.num_bytes));
+                               ret = btrfs_free_extent(trans, root,
+                                               old_disk_bytenr,
+                                               le64_to_cpu(old.disk_num_bytes),
+                                               0, root->root_key.objectid,
+                                               key.objectid, key.offset -
+                                               le64_to_cpu(old.offset));
+                               BUG_ON(ret);
+                               *hint_byte = old_disk_bytenr;
                        }
+               }
+
+               if (search_start >= end) {
                        ret = 0;
                        goto out;
                }
        }
 out:
        btrfs_free_path(path);
-       btrfs_check_file(root, inode);
+       if (locked_end > orig_locked_end) {
+               unlock_extent(&BTRFS_I(inode)->io_tree, orig_locked_end,
+                             locked_end - 1, GFP_NOFS);
+       }
        return ret;
 }
 
+static int extent_mergeable(struct extent_buffer *leaf, int slot,
+                           u64 objectid, u64 bytenr, u64 *start, u64 *end)
+{
+       struct btrfs_file_extent_item *fi;
+       struct btrfs_key key;
+       u64 extent_end;
+
+       if (slot < 0 || slot >= btrfs_header_nritems(leaf))
+               return 0;
+
+       btrfs_item_key_to_cpu(leaf, &key, slot);
+       if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
+               return 0;
+
+       fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+       if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
+           btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
+           btrfs_file_extent_compression(leaf, fi) ||
+           btrfs_file_extent_encryption(leaf, fi) ||
+           btrfs_file_extent_other_encoding(leaf, fi))
+               return 0;
+
+       extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+       if ((*start && *start != key.offset) || (*end && *end != extent_end))
+               return 0;
+
+       *start = key.offset;
+       *end = extent_end;
+       return 1;
+}
+
 /*
- * this gets pages into the page cache and locks them down
+ * Mark extent in the range start - end as written.
+ *
+ * This changes extent type from 'pre-allocated' to 'regular'. If only
+ * part of extent is marked as written, the extent will be split into
+ * two or three.
  */
-static int noinline prepare_pages(struct btrfs_root *root, struct file *file,
+int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct inode *inode, u64 start, u64 end)
+{
+       struct extent_buffer *leaf;
+       struct btrfs_path *path;
+       struct btrfs_file_extent_item *fi;
+       struct btrfs_key key;
+       u64 bytenr;
+       u64 num_bytes;
+       u64 extent_end;
+       u64 orig_offset;
+       u64 other_start;
+       u64 other_end;
+       u64 split = start;
+       u64 locked_end = end;
+       int extent_type;
+       int split_end = 1;
+       int ret;
+
+       btrfs_drop_extent_cache(inode, start, end - 1, 0);
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+again:
+       key.objectid = inode->i_ino;
+       key.type = BTRFS_EXTENT_DATA_KEY;
+       if (split == start)
+               key.offset = split;
+       else
+               key.offset = split - 1;
+
+       ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+       if (ret > 0 && path->slots[0] > 0)
+               path->slots[0]--;
+
+       leaf = path->nodes[0];
+       btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+       BUG_ON(key.objectid != inode->i_ino ||
+              key.type != BTRFS_EXTENT_DATA_KEY);
+       fi = btrfs_item_ptr(leaf, path->slots[0],
+                           struct btrfs_file_extent_item);
+       extent_type = btrfs_file_extent_type(leaf, fi);
+       BUG_ON(extent_type != BTRFS_FILE_EXTENT_PREALLOC);
+       extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+       BUG_ON(key.offset > start || extent_end < end);
+
+       bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+       num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+       orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
+
+       if (key.offset == start)
+               split = end;
+
+       if (key.offset == start && extent_end == end) {
+               int del_nr = 0;
+               int del_slot = 0;
+               other_start = end;
+               other_end = 0;
+               if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino,
+                                    bytenr, &other_start, &other_end)) {
+                       extent_end = other_end;
+                       del_slot = path->slots[0] + 1;
+                       del_nr++;
+                       ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
+                                               0, root->root_key.objectid,
+                                               inode->i_ino, orig_offset);
+                       BUG_ON(ret);
+               }
+               other_start = 0;
+               other_end = start;
+               if (extent_mergeable(leaf, path->slots[0] - 1, inode->i_ino,
+                                    bytenr, &other_start, &other_end)) {
+                       key.offset = other_start;
+                       del_slot = path->slots[0];
+                       del_nr++;
+                       ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
+                                               0, root->root_key.objectid,
+                                               inode->i_ino, orig_offset);
+                       BUG_ON(ret);
+               }
+               split_end = 0;
+               if (del_nr == 0) {
+                       btrfs_set_file_extent_type(leaf, fi,
+                                                  BTRFS_FILE_EXTENT_REG);
+                       goto done;
+               }
+
+               fi = btrfs_item_ptr(leaf, del_slot - 1,
+                                   struct btrfs_file_extent_item);
+               btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
+               btrfs_set_file_extent_num_bytes(leaf, fi,
+                                               extent_end - key.offset);
+               btrfs_mark_buffer_dirty(leaf);
+
+               ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
+               BUG_ON(ret);
+               goto release;
+       } else if (split == start) {
+               if (locked_end < extent_end) {
+                       ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
+                                       locked_end, extent_end - 1, GFP_NOFS);
+                       if (!ret) {
+                               btrfs_release_path(root, path);
+                               lock_extent(&BTRFS_I(inode)->io_tree,
+                                       locked_end, extent_end - 1, GFP_NOFS);
+                               locked_end = extent_end;
+                               goto again;
+                       }
+                       locked_end = extent_end;
+               }
+               btrfs_set_file_extent_num_bytes(leaf, fi, split - key.offset);
+       } else  {
+               BUG_ON(key.offset != start);
+               key.offset = split;
+               btrfs_set_file_extent_offset(leaf, fi, key.offset -
+                                            orig_offset);
+               btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - split);
+               btrfs_set_item_key_safe(trans, root, path, &key);
+               extent_end = split;
+       }
+
+       if (extent_end == end) {
+               split_end = 0;
+               extent_type = BTRFS_FILE_EXTENT_REG;
+       }
+       if (extent_end == end && split == start) {
+               other_start = end;
+               other_end = 0;
+               if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino,
+                                    bytenr, &other_start, &other_end)) {
+                       path->slots[0]++;
+                       fi = btrfs_item_ptr(leaf, path->slots[0],
+                                           struct btrfs_file_extent_item);
+                       key.offset = split;
+                       btrfs_set_item_key_safe(trans, root, path, &key);
+                       btrfs_set_file_extent_offset(leaf, fi, key.offset -
+                                                    orig_offset);
+                       btrfs_set_file_extent_num_bytes(leaf, fi,
+                                                       other_end - split);
+                       goto done;
+               }
+       }
+       if (extent_end == end && split == end) {
+               other_start = 0;
+               other_end = start;
+               if (extent_mergeable(leaf, path->slots[0] - 1 , inode->i_ino,
+                                    bytenr, &other_start, &other_end)) {
+                       path->slots[0]--;
+                       fi = btrfs_item_ptr(leaf, path->slots[0],
+                                           struct btrfs_file_extent_item);
+                       btrfs_set_file_extent_num_bytes(leaf, fi, extent_end -
+                                                       other_start);
+                       goto done;
+               }
+       }
+
+       btrfs_mark_buffer_dirty(leaf);
+
+       ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
+                                  root->root_key.objectid,
+                                  inode->i_ino, orig_offset);
+       BUG_ON(ret);
+       btrfs_release_path(root, path);
+
+       key.offset = start;
+       ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*fi));
+       BUG_ON(ret);
+
+       leaf = path->nodes[0];
+       fi = btrfs_item_ptr(leaf, path->slots[0],
+                           struct btrfs_file_extent_item);
+       btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+       btrfs_set_file_extent_type(leaf, fi, extent_type);
+       btrfs_set_file_extent_disk_bytenr(leaf, fi, bytenr);
+       btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
+       btrfs_set_file_extent_offset(leaf, fi, key.offset - orig_offset);
+       btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - key.offset);
+       btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
+       btrfs_set_file_extent_compression(leaf, fi, 0);
+       btrfs_set_file_extent_encryption(leaf, fi, 0);
+       btrfs_set_file_extent_other_encoding(leaf, fi, 0);
+done:
+       btrfs_mark_buffer_dirty(leaf);
+
+release:
+       btrfs_release_path(root, path);
+       if (split_end && split == start) {
+               split = end;
+               goto again;
+       }
+       if (locked_end > end) {
+               unlock_extent(&BTRFS_I(inode)->io_tree, end, locked_end - 1,
+                             GFP_NOFS);
+       }
+       btrfs_free_path(path);
+       return 0;
+}
+
+/*
+ * this gets pages into the page cache and locks them down, it also properly
+ * waits for data=ordered extents to finish before allowing the pages to be
+ * modified.
+ */
+static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
                         struct page **pages, size_t num_pages,
                         loff_t pos, unsigned long first_index,
                         unsigned long last_index, size_t write_bytes)
@@ -803,6 +835,12 @@ static int noinline prepare_pages(struct btrfs_root *root, struct file *file,
        start_pos = pos & ~((u64)root->sectorsize - 1);
        last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
 
+       if (start_pos > inode->i_size) {
+               err = btrfs_cont_expand(inode, start_pos);
+               if (err)
+                       return err;
+       }
+
        memset(pages, 0, num_pages * sizeof(struct page *));
 again:
        for (i = 0; i < num_pages; i++) {
@@ -817,7 +855,8 @@ again:
                struct btrfs_ordered_extent *ordered;
                lock_extent(&BTRFS_I(inode)->io_tree,
                            start_pos, last_pos - 1, GFP_NOFS);
-               ordered = btrfs_lookup_first_ordered_extent(inode, last_pos -1);
+               ordered = btrfs_lookup_first_ordered_extent(inode,
+                                                           last_pos - 1);
                if (ordered &&
                    ordered->file_offset + ordered->len > start_pos &&
                    ordered->file_offset < last_pos) {
@@ -864,6 +903,10 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        struct page *pinned[2];
        unsigned long first_index;
        unsigned long last_index;
+       int will_write;
+
+       will_write = ((file->f_flags & O_SYNC) || IS_SYNC(inode) ||
+                     (file->f_flags & O_DIRECT));
 
        nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
                     PAGE_CACHE_SIZE / (sizeof(struct page *)));
@@ -880,15 +923,8 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                goto out_nolock;
        if (count == 0)
                goto out_nolock;
-#ifdef REMOVE_SUID_PATH
-       err = remove_suid(&file->f_path);
-#else
-# if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
+
        err = file_remove_suid(file);
-# else
-       err = remove_suid(fdentry(file));
-# endif
-#endif
        if (err)
                goto out_nolock;
        file_update_time(file);
@@ -896,18 +932,11 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
 
        mutex_lock(&inode->i_mutex);
+       BTRFS_I(inode)->sequence++;
        first_index = pos >> PAGE_CACHE_SHIFT;
        last_index = (pos + count) >> PAGE_CACHE_SHIFT;
 
        /*
-        * if this is a nodatasum mount, force summing off for the inode
-        * all the time.  That way a later mount with summing on won't
-        * get confused
-        */
-       if (btrfs_test_opt(root, NODATASUM))
-               btrfs_set_flag(inode, NODATASUM);
-
-       /*
         * there are lots of better ways to do this, but this code
         * makes sure the first and last page in the file range are
         * up to date and ready for cow
@@ -933,7 +962,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                }
        }
 
-       while(count > 0) {
+       while (count > 0) {
                size_t offset = pos & (PAGE_CACHE_SIZE - 1);
                size_t write_bytes = min(count, nrptrs *
                                        (size_t)PAGE_CACHE_SIZE -
@@ -942,21 +971,26 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                                        PAGE_CACHE_SHIFT;
 
                WARN_ON(num_pages > nrptrs);
-               memset(pages, 0, sizeof(pages));
+               memset(pages, 0, sizeof(struct page *) * nrptrs);
 
-               ret = btrfs_check_free_space(root, write_bytes, 0);
+               ret = btrfs_check_data_free_space(root, inode, write_bytes);
                if (ret)
                        goto out;
 
                ret = prepare_pages(root, file, pages, num_pages,
                                    pos, first_index, last_index,
                                    write_bytes);
-               if (ret)
+               if (ret) {
+                       btrfs_free_reserved_data_space(root, inode,
+                                                      write_bytes);
                        goto out;
+               }
 
                ret = btrfs_copy_from_user(pos, num_pages,
                                           write_bytes, pages, buf);
                if (ret) {
+                       btrfs_free_reserved_data_space(root, inode,
+                                                      write_bytes);
                        btrfs_drop_pages(pages, num_pages);
                        goto out;
                }
@@ -964,22 +998,36 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                ret = dirty_and_release_pages(NULL, root, file, pages,
                                              num_pages, pos, write_bytes);
                btrfs_drop_pages(pages, num_pages);
-               if (ret)
+               if (ret) {
+                       btrfs_free_reserved_data_space(root, inode,
+                                                      write_bytes);
                        goto out;
+               }
+
+               if (will_write) {
+                       btrfs_fdatawrite_range(inode->i_mapping, pos,
+                                              pos + write_bytes - 1,
+                                              WB_SYNC_ALL);
+               } else {
+                       balance_dirty_pages_ratelimited_nr(inode->i_mapping,
+                                                          num_pages);
+                       if (num_pages <
+                           (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
+                               btrfs_btree_balance_dirty(root, 1);
+                       btrfs_throttle(root);
+               }
 
                buf += write_bytes;
                count -= write_bytes;
                pos += write_bytes;
                num_written += write_bytes;
 
-               balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
-               if (num_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
-                       btrfs_btree_balance_dirty(root, 1);
-               btrfs_throttle(root);
                cond_resched();
        }
 out:
        mutex_unlock(&inode->i_mutex);
+       if (ret)
+               err = ret;
 
 out_nolock:
        kfree(pages);
@@ -989,55 +1037,81 @@ out_nolock:
                page_cache_release(pinned[1]);
        *ppos = pos;
 
-       if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
-               struct btrfs_trans_handle *trans;
+       /*
+        * we want to make sure fsync finds this change
+        * but we haven't joined a transaction running right now.
+        *
+        * Later on, someone is sure to update the inode and get the
+        * real transid recorded.
+        *
+        * We set last_trans now to the fs_info generation + 1,
+        * this will either be one more than the running transaction
+        * or the generation used for the next transaction if there isn't
+        * one running right now.
+        */
+       BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
 
-               err = btrfs_fdatawrite_range(inode->i_mapping, start_pos,
-                                            start_pos + num_written -1,
-                                            WB_SYNC_NONE);
-               if (err < 0)
-                       num_written = err;
+       if (num_written > 0 && will_write) {
+               struct btrfs_trans_handle *trans;
 
-               err = btrfs_wait_on_page_writeback_range(inode->i_mapping,
-                                start_pos, start_pos + num_written - 1);
-               if (err < 0)
+               err = btrfs_wait_ordered_range(inode, start_pos, num_written);
+               if (err)
                        num_written = err;
 
-               trans = btrfs_start_transaction(root, 1);
-               ret = btrfs_log_dentry_safe(trans, root, file->f_dentry);
-               if (ret == 0) {
-                       btrfs_sync_log(trans, root);
-                       btrfs_end_transaction(trans, root);
-               } else {
-                       btrfs_commit_transaction(trans, root);
+               if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {
+                       trans = btrfs_start_transaction(root, 1);
+                       ret = btrfs_log_dentry_safe(trans, root,
+                                                   file->f_dentry);
+                       if (ret == 0) {
+                               ret = btrfs_sync_log(trans, root);
+                               if (ret == 0)
+                                       btrfs_end_transaction(trans, root);
+                               else
+                                       btrfs_commit_transaction(trans, root);
+                       } else {
+                               btrfs_commit_transaction(trans, root);
+                       }
+               }
+               if (file->f_flags & O_DIRECT) {
+                       invalidate_mapping_pages(inode->i_mapping,
+                             start_pos >> PAGE_CACHE_SHIFT,
+                            (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
                }
-       } else if (num_written > 0 && (file->f_flags & O_DIRECT)) {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
-               do_sync_file_range(file, start_pos,
-                                     start_pos + num_written - 1,
-                                     SYNC_FILE_RANGE_WRITE |
-                                     SYNC_FILE_RANGE_WAIT_AFTER);
-#else
-               do_sync_mapping_range(inode->i_mapping, start_pos,
-                                     start_pos + num_written - 1,
-                                     SYNC_FILE_RANGE_WRITE |
-                                     SYNC_FILE_RANGE_WAIT_AFTER);
-#endif
-               invalidate_mapping_pages(inode->i_mapping,
-                     start_pos >> PAGE_CACHE_SHIFT,
-                    (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
        }
        current->backing_dev_info = NULL;
        return num_written ? num_written : err;
 }
 
-int btrfs_release_file(struct inode * inode, struct file * filp)
+int btrfs_release_file(struct inode *inode, struct file *filp)
 {
+       /*
+        * ordered_data_close is set by settattr when we are about to truncate
+        * a file from a non-zero size to a zero size.  This tries to
+        * flush down new bytes that may have been written if the
+        * application were using truncate to replace a file in place.
+        */
+       if (BTRFS_I(inode)->ordered_data_close) {
+               BTRFS_I(inode)->ordered_data_close = 0;
+               btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
+               if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
+                       filemap_flush(inode->i_mapping);
+       }
        if (filp->private_data)
                btrfs_ioctl_trans_end(filp);
        return 0;
 }
 
+/*
+ * fsync call for both files and directories.  This logs the inode into
+ * the tree log instead of forcing full commits whenever possible.
+ *
+ * It needs to call filemap_fdatawait so that all ordered extent updates are
+ * in the metadata btree are up to date for copying to the log.
+ *
+ * It drops the inode mutex before doing the tree log commit.  This is an
+ * important optimization for directories because holding the mutex prevents
+ * new operations on the dir while we write to disk.
+ */
 int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
 {
        struct inode *inode = dentry->d_inode;
@@ -1061,12 +1135,17 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
        }
        mutex_unlock(&root->fs_info->trans_mutex);
 
-       filemap_fdatawait(inode->i_mapping);
+       root->log_batch++;
+       filemap_fdatawrite(inode->i_mapping);
+       btrfs_wait_ordered_range(inode, 0, (u64)-1);
+       root->log_batch++;
 
+       if (datasync && !(inode->i_state & I_DIRTY_PAGES))
+               goto out;
        /*
         * ok we haven't committed the transaction yet, lets do a commit
         */
-       if (file->private_data)
+       if (file && file->private_data)
                btrfs_ioctl_trans_end(file);
 
        trans = btrfs_start_transaction(root, 1);
@@ -1075,26 +1154,38 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
                goto out;
        }
 
-       ret = btrfs_log_dentry_safe(trans, root, file->f_dentry);
+       ret = btrfs_log_dentry_safe(trans, root, dentry);
        if (ret < 0)
                goto out;
+
+       /* we've logged all the items and now have a consistent
+        * version of the file in the log.  It is possible that
+        * someone will come in and modify the file, but that's
+        * fine because the log is consistent on disk, and we
+        * have references to all of the file's extents
+        *
+        * It is possible that someone will come in and log the
+        * file again, but that will end up using the synchronization
+        * inside btrfs_sync_log to keep things safe.
+        */
+       mutex_unlock(&dentry->d_inode->i_mutex);
+
        if (ret > 0) {
                ret = btrfs_commit_transaction(trans, root);
        } else {
-               btrfs_sync_log(trans, root);
-               ret = btrfs_end_transaction(trans, root);
+               ret = btrfs_sync_log(trans, root);
+               if (ret == 0)
+                       ret = btrfs_end_transaction(trans, root);
+               else
+                       ret = btrfs_commit_transaction(trans, root);
        }
+       mutex_lock(&dentry->d_inode->i_mutex);
 out:
        return ret > 0 ? EIO : ret;
 }
 
-static struct vm_operations_struct btrfs_file_vm_ops = {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
-       .nopage         = filemap_nopage,
-       .populate       = filemap_populate,
-#else
+static const struct vm_operations_struct btrfs_file_vm_ops = {
        .fault          = filemap_fault,
-#endif
        .page_mkwrite   = btrfs_page_mkwrite,
 };
 
@@ -1105,14 +1196,11 @@ static int btrfs_file_mmap(struct file  *filp, struct vm_area_struct *vma)
        return 0;
 }
 
-struct file_operations btrfs_file_operations = {
+const struct file_operations btrfs_file_operations = {
        .llseek         = generic_file_llseek,
        .read           = do_sync_read,
        .aio_read       = generic_file_aio_read,
        .splice_read    = generic_file_splice_read,
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
-       .sendfile       = generic_file_sendfile,
-#endif
        .write          = btrfs_file_write,
        .mmap           = btrfs_file_mmap,
        .open           = generic_file_open,