NTFS: Enable ATTR_SIZE attribute changes in ntfs_setattr(). This completes

      the initial implementation of file truncation.  Now both open(2)ing
      a file with the O_TRUNC flag and the {,f}truncate(2) system calls
      will resize a file appropriately.  The limitations are that only
      uncompressed and unencrypted files are supported.  Also, there is
      only very limited support for highly fragmented files (the ones whose
      $DATA attribute is split into multiple attribute extents).

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>

2 files changed, 22 insertions, 8 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 70ad4be7a7fe..9f4674a026f2 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -50,6 +50,13 @@ ToDo/Notes:
           but not the initialized size can be extended, too.
         - Implement fs/ntfs/inode.[hc]::ntfs_truncate().  It only supports
           uncompressed and unencrypted files.
+        - Enable ATTR_SIZE attribute changes in ntfs_setattr().  This completes
+          the initial implementation of file truncation.  Now both open(2)ing
+          a file with the O_TRUNC flag and the {,f}truncate(2) system calls
+          will resize a file appropriately.  The limitations are that only
+          uncompressed and unencrypted files are supported.  Also, there is
+          only very limited support for highly fragmented files (the ones whose
+          $DATA attribute is split into multiple attribute extents).
 
 2.1.24 - Lots of bug fixes and support more clean journal states.
 
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index a1682342baa6..b24f4c4b2c5c 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -2845,8 +2845,7 @@ int ntfs_setattr(struct dentry *dentry, struct iattr *attr)
 
         err = inode_change_ok(vi, attr);
         if (err)
-                return err;
-
+                goto out;
         /* We do not support NTFS ACLs yet. */
         if (ia_valid & (ATTR_UID | ATTR_GID | ATTR_MODE)) {
                 ntfs_warning(vi->i_sb, "Changes in user/group/mode are not "
@@ -2854,14 +2853,22 @@ int ntfs_setattr(struct dentry *dentry, struct iattr *attr)
                 err = -EOPNOTSUPP;
                 goto out;
         }
-
         if (ia_valid & ATTR_SIZE) {
                 if (attr->ia_size != i_size_read(vi)) {
-                        ntfs_warning(vi->i_sb, "Changes in inode size are not "
-                                        "supported yet, ignoring.");
-                        err = -EOPNOTSUPP;
-                        // TODO: Implement...
-                        // err = vmtruncate(vi, attr->ia_size);
+                        ntfs_inode *ni = NTFS_I(vi);
+                        /*
+                         * FIXME: For now we do not support resizing of
+                         * compressed or encrypted files yet.
+                         */
+                        if (NInoCompressed(ni) || NInoEncrypted(ni)) {
+                                ntfs_warning(vi->i_sb, "Changes in inode size "
+                                                "are not supported yet for "
+                                                "%s files, ignoring.",
+                                                NInoCompressed(ni) ?
+                                                "compressed" : "encrypted");
+                                err = -EOPNOTSUPP;
+                        } else
+                                err = vmtruncate(vi, attr->ia_size);
                         if (err || ia_valid == ATTR_SIZE)
                                 goto out;
                 } else {