Btrfs: skip writeback of last page when truncating file to same size

[sfrench/cifs-2.6.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index be167f5ec433dbd22c7c6efe99c44e9a6d2190a4..6dbdde9a798ed6a9fc62b2ec881ddf0d25c0ab4b 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -101,7 +101,7 @@ static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
 };
 
 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
-static int btrfs_truncate(struct inode *inode);
+static int btrfs_truncate(struct inode *inode, bool skip_writeback);
 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
 static noinline int cow_file_range(struct inode *inode,
                                   struct page *locked_page,
@@ -3668,7 +3668,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
                                goto out;
                        }
 
-                       ret = btrfs_truncate(inode);
+                       ret = btrfs_truncate(inode, false);
                        if (ret)
                                btrfs_orphan_del(NULL, BTRFS_I(inode));
                } else {
@@ -5154,7 +5154,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
                inode_dio_wait(inode);
                btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
 
-               ret = btrfs_truncate(inode);
+               ret = btrfs_truncate(inode, newsize == oldsize);
                if (ret && inode->i_nlink) {
                        int err;
 
@@ -9136,7 +9136,7 @@ out_noreserve:
        return ret;
 }
 
-static int btrfs_truncate(struct inode *inode)
+static int btrfs_truncate(struct inode *inode, bool skip_writeback)
 {
        struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
        struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -9147,10 +9147,12 @@ static int btrfs_truncate(struct inode *inode)
        u64 mask = fs_info->sectorsize - 1;
        u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
 
-       ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
-                                      (u64)-1);
-       if (ret)
-               return ret;
+       if (!skip_writeback) {
+               ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
+                                              (u64)-1);
+               if (ret)
+                       return ret;
+       }
 
        /*
         * Yes ladies and gentlemen, this is indeed ugly.  The fact is we have