Merge master.kernel.org:/home/rmk/linux-2.6-arm
[safe/jmp/linux-2.6] / fs / btrfs / file.c
index 71bfe3a..f19e125 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"
 /* simple helper to fault in pages and copy.  This should go away
  * and be replaced with calls into generic code.
  */
-static int noinline btrfs_copy_from_user(loff_t pos, int num_pages,
+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;
@@ -78,7 +76,7 @@ static int noinline btrfs_copy_from_user(loff_t pos, int num_pages,
 /*
  * unlocks pages after btrfs_file_write is done with them
  */
-static void noinline btrfs_drop_pages(struct page **pages, size_t num_pages)
+static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages)
 {
        size_t i;
        for (i = 0; i < num_pages; i++) {
@@ -103,7 +101,7 @@ static void noinline btrfs_drop_pages(struct page **pages, size_t num_pages)
  * this also makes the decision about creating an inline extent vs
  * doing real data extents, marking pages dirty and delalloc as required.
  */
-static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
+static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
                                   struct btrfs_root *root,
                                   struct file *file,
                                   struct page **pages,
@@ -114,8 +112,6 @@ 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;
@@ -127,26 +123,10 @@ 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;
+       err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block);
+       if (err)
+               return err;
 
-       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);
-
-       /* 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);
@@ -155,11 +135,11 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
        }
        if (end_pos > isize) {
                i_size_write(inode, 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.
+                */
        }
-       err = btrfs_end_transaction(trans, root);
-out_unlock:
-       unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
        return err;
 }
 
@@ -185,24 +165,24 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
                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)) {
-                       spin_unlock(&em_tree->lock);
                        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) {
@@ -212,6 +192,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
                                start = em->start + em->len;
                        }
                        free_extent_map(em);
+                       write_unlock(&em_tree->lock);
                        continue;
                }
                compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
@@ -262,7 +243,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
                        free_extent_map(split);
                        split = NULL;
                }
-               spin_unlock(&em_tree->lock);
+               write_unlock(&em_tree->lock);
 
                /* once for us */
                free_extent_map(em);
@@ -276,80 +257,6 @@ int 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, extent);
-                       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
@@ -362,22 +269,19 @@ out:
  * 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 locked_end = end;
        u64 search_start = start;
-       u64 leaf_start;
        u64 ram_bytes = 0;
-       u64 orig_parent = 0;
        u64 disk_bytenr = 0;
+       u64 orig_locked_end = locked_end;
        u8 compression;
        u8 encryption;
        u16 other_encoding = 0;
-       u64 root_gen;
-       u64 root_owner;
        struct extent_buffer *leaf;
        struct btrfs_file_extent_item *extent;
        struct btrfs_path *path;
@@ -393,12 +297,13 @@ int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans,
        int ret;
 
        inline_limit = 0;
-       btrfs_drop_extent_cache(inode, start, end - 1, 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,
@@ -417,9 +322,6 @@ next_slot:
                bookend = 0;
                found_extent = 0;
                found_inline = 0;
-               leaf_start = 0;
-               root_gen = 0;
-               root_owner = 0;
                compression = 0;
                encryption = 0;
                extent = NULL;
@@ -494,9 +396,6 @@ next_slot:
                if (found_extent) {
                        read_extent_buffer(leaf, &old, (unsigned long)extent,
                                           sizeof(old));
-                       root_gen = btrfs_header_generation(leaf);
-                       root_owner = btrfs_header_owner(leaf);
-                       leaf_start = leaf->start;
                }
 
                if (end < extent_end && end >= key.offset) {
@@ -520,14 +419,14 @@ next_slot:
                                }
                                locked_end = extent_end;
                        }
-                       orig_parent = path->nodes[0]->start;
                        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),
-                                          orig_parent, root->root_key.objectid,
-                                          trans->transid, inode->i_ino);
+                                          le64_to_cpu(old.disk_num_bytes), 0,
+                                          root->root_key.objectid,
+                                          key.objectid, key.offset -
+                                          le64_to_cpu(old.offset));
                                BUG_ON(ret);
                        }
                }
@@ -556,10 +455,6 @@ next_slot:
                                        inode_sub_bytes(inode, old_num -
                                                        new_num);
                                }
-                               if (!compression && !encryption) {
-                                       btrfs_set_file_extent_ram_bytes(leaf,
-                                                       extent, new_num);
-                               }
                                btrfs_set_file_extent_num_bytes(leaf,
                                                        extent, new_num);
                                btrfs_mark_buffer_dirty(leaf);
@@ -611,6 +506,7 @@ next_slot:
                        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);
@@ -644,21 +540,14 @@ next_slot:
                                                        ram_bytes);
                        btrfs_set_file_extent_type(leaf, extent, found_type);
 
+                       btrfs_unlock_up_safe(path, 1);
                        btrfs_mark_buffer_dirty(path->nodes[0]);
+                       btrfs_set_lock_blocking(path->nodes[0]);
 
-                       if (disk_bytenr != 0) {
-                               ret = btrfs_update_extent_ref(trans, root,
-                                               disk_bytenr, orig_parent,
-                                               leaf->start,
-                                               root->root_key.objectid,
-                                               trans->transid, ins.objectid);
-
-                               BUG_ON(ret);
-                       }
+                       path->leave_spinning = 0;
                        btrfs_release_path(root, path);
-                       if (disk_bytenr != 0) {
+                       if (disk_bytenr != 0)
                                inode_add_bytes(inode, extent_end - end);
-                       }
                }
 
                if (found_extent && !keep) {
@@ -670,8 +559,9 @@ next_slot:
                                ret = btrfs_free_extent(trans, root,
                                                old_disk_bytenr,
                                                le64_to_cpu(old.disk_num_bytes),
-                                               leaf_start, root_owner,
-                                               root_gen, key.objectid, 0);
+                                               0, root->root_key.objectid,
+                                               key.objectid, key.offset -
+                                               le64_to_cpu(old.offset));
                                BUG_ON(ret);
                                *hint_byte = old_disk_bytenr;
                        }
@@ -684,11 +574,10 @@ next_slot:
        }
 out:
        btrfs_free_path(path);
-       if (locked_end > end) {
-               unlock_extent(&BTRFS_I(inode)->io_tree, end, locked_end - 1,
-                             GFP_NOFS);
+       if (locked_end > orig_locked_end) {
+               unlock_extent(&BTRFS_I(inode)->io_tree, orig_locked_end,
+                             locked_end - 1, GFP_NOFS);
        }
-       btrfs_check_file(root, inode);
        return ret;
 }
 
@@ -741,12 +630,11 @@ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
        u64 bytenr;
        u64 num_bytes;
        u64 extent_end;
-       u64 extent_offset;
+       u64 orig_offset;
        u64 other_start;
        u64 other_end;
        u64 split = start;
        u64 locked_end = end;
-       u64 orig_parent;
        int extent_type;
        int split_end = 1;
        int ret;
@@ -780,7 +668,7 @@ again:
 
        bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
        num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
-       extent_offset = btrfs_file_extent_offset(leaf, fi);
+       orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
 
        if (key.offset == start)
                split = end;
@@ -788,8 +676,6 @@ again:
        if (key.offset == start && extent_end == end) {
                int del_nr = 0;
                int del_slot = 0;
-               u64 leaf_owner = btrfs_header_owner(leaf);
-               u64 leaf_gen = btrfs_header_generation(leaf);
                other_start = end;
                other_end = 0;
                if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino,
@@ -798,8 +684,8 @@ again:
                        del_slot = path->slots[0] + 1;
                        del_nr++;
                        ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
-                                               leaf->start, leaf_owner,
-                                               leaf_gen, inode->i_ino, 0);
+                                               0, root->root_key.objectid,
+                                               inode->i_ino, orig_offset);
                        BUG_ON(ret);
                }
                other_start = 0;
@@ -810,8 +696,8 @@ again:
                        del_slot = path->slots[0];
                        del_nr++;
                        ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
-                                               leaf->start, leaf_owner,
-                                               leaf_gen, inode->i_ino, 0);
+                                               0, root->root_key.objectid,
+                                               inode->i_ino, orig_offset);
                        BUG_ON(ret);
                }
                split_end = 0;
@@ -830,7 +716,7 @@ again:
 
                ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
                BUG_ON(ret);
-               goto done;
+               goto release;
        } else if (split == start) {
                if (locked_end < extent_end) {
                        ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
@@ -845,13 +731,12 @@ again:
                        locked_end = extent_end;
                }
                btrfs_set_file_extent_num_bytes(leaf, fi, split - key.offset);
-               extent_offset += split - key.offset;
        } else  {
                BUG_ON(key.offset != start);
-               btrfs_set_file_extent_offset(leaf, fi, extent_offset +
-                                            split - key.offset);
-               btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - split);
                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;
        }
@@ -870,7 +755,8 @@ again:
                                            struct btrfs_file_extent_item);
                        key.offset = split;
                        btrfs_set_item_key_safe(trans, root, path, &key);
-                       btrfs_set_file_extent_offset(leaf, fi, extent_offset);
+                       btrfs_set_file_extent_offset(leaf, fi, key.offset -
+                                                    orig_offset);
                        btrfs_set_file_extent_num_bytes(leaf, fi,
                                                        other_end - split);
                        goto done;
@@ -892,10 +778,9 @@ again:
 
        btrfs_mark_buffer_dirty(leaf);
 
-       orig_parent = leaf->start;
-       ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
-                                  orig_parent, root->root_key.objectid,
-                                  trans->transid, inode->i_ino);
+       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);
 
@@ -910,22 +795,16 @@ again:
        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, extent_offset);
+       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);
-
-       if (orig_parent != leaf->start) {
-               ret = btrfs_update_extent_ref(trans, root, bytenr,
-                                             orig_parent, leaf->start,
-                                             root->root_key.objectid,
-                                             trans->transid, inode->i_ino);
-               BUG_ON(ret);
-       }
 done:
        btrfs_mark_buffer_dirty(leaf);
+
+release:
        btrfs_release_path(root, path);
        if (split_end && split == start) {
                split = end;
@@ -944,7 +823,7 @@ done:
  * waits for data=ordered extents to finish before allowing the pages to be
  * modified.
  */
-static int noinline prepare_pages(struct btrfs_root *root, struct file *file,
+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)
@@ -979,7 +858,8 @@ 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) {
@@ -1040,34 +920,40 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        start_pos = pos;
 
        vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
+       /* do the reserve before the mutex lock in case we have to do some
+        * flushing.  We wouldn't deadlock, but this is more polite.
+        */
+       err = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
+       if (err)
+               goto out_nolock;
+
+       mutex_lock(&inode->i_mutex);
+
        current->backing_dev_info = inode->i_mapping->backing_dev_info;
        err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
        if (err)
-               goto out_nolock;
+               goto out;
+
        if (count == 0)
-               goto out_nolock;
+               goto out;
 
        err = file_remove_suid(file);
        if (err)
-               goto out_nolock;
+               goto out;
+
        file_update_time(file);
 
        pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
 
-       mutex_lock(&inode->i_mutex);
+       /* generic_write_checks can change our pos */
+       start_pos = pos;
+
        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
@@ -1093,7 +979,7 @@ 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 -
@@ -1102,21 +988,26 @@ 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;
                }
@@ -1124,13 +1015,15 @@ 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_NONE);
+                       filemap_fdatawrite_range(inode->i_mapping, pos,
+                                                pos + write_bytes - 1);
                } else {
                        balance_dirty_pages_ratelimited_nr(inode->i_mapping,
                                                           num_pages);
@@ -1149,6 +1042,9 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
        }
 out:
        mutex_unlock(&inode->i_mutex);
+       if (ret)
+               err = ret;
+       btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
 
 out_nolock:
        kfree(pages);
@@ -1158,6 +1054,20 @@ out_nolock:
                page_cache_release(pinned[1]);
        *ppos = pos;
 
+       /*
+        * 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;
+
        if (num_written > 0 && will_write) {
                struct btrfs_trans_handle *trans;
 
@@ -1170,8 +1080,11 @@ out_nolock:
                        ret = btrfs_log_dentry_safe(trans, root,
                                                    file->f_dentry);
                        if (ret == 0) {
-                               btrfs_sync_log(trans, root);
-                               btrfs_end_transaction(trans, root);
+                               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);
                        }
@@ -1186,8 +1099,20 @@ out_nolock:
        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;
@@ -1227,15 +1152,17 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
        }
        mutex_unlock(&root->fs_info->trans_mutex);
 
-       root->fs_info->tree_log_batch++;
+       root->log_batch++;
        filemap_fdatawrite(inode->i_mapping);
        btrfs_wait_ordered_range(inode, 0, (u64)-1);
-       root->fs_info->tree_log_batch++;
+       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);
@@ -1244,10 +1171,9 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
                goto out;
        }
 
-       ret = btrfs_log_dentry_safe(trans, root, file->f_dentry);
-       if (ret < 0) {
+       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
@@ -1259,20 +1185,23 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
         * file again, but that will end up using the synchronization
         * inside btrfs_sync_log to keep things safe.
         */
-       mutex_unlock(&file->f_dentry->d_inode->i_mutex);
+       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(&file->f_dentry->d_inode->i_mutex);
+       mutex_lock(&dentry->d_inode->i_mutex);
 out:
        return ret > 0 ? EIO : ret;
 }
 
-static struct vm_operations_struct btrfs_file_vm_ops = {
+static const struct vm_operations_struct btrfs_file_vm_ops = {
        .fault          = filemap_fault,
        .page_mkwrite   = btrfs_page_mkwrite,
 };
@@ -1284,7 +1213,7 @@ 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,