[PATCH] xfs: lseek SEEK_DATA/SEEK_HOLE consolidation

[Jeff Liu]

From: Jie Liu <jeff.liu at oracle.com>

Consolidate lseek(2) SEEK_DATA/SEEK_HOLE according to the
implementation of VFS lseek_execute():
- if end up with a negative offset, return EINVAL if file
  is not huge.
- if end up with an offset larger than s_maxbytes, return
  EINVAL as well.
- reset file version to 0 if end up with an offset that is
  not equal to the current file offset.

Signed-off-by: Jie Liu <jeff.liu at oracle.com>

---
 fs/xfs/xfs_file.c |   26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index a5f2042..dc42751 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1270,8 +1270,19 @@ xfs_seek_data(
 	}
 
 out:
-	if (offset != file->f_pos)
+	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
+		error = EINVAL;
+		goto out_unlock;
+	}
+	if (offset > inode->i_sb->s_maxbytes) {
+		error = EINVAL;
+		goto out_unlock;
+	}
+
+	if (offset != file->f_pos) {
 		file->f_pos = offset;
+		file->f_version = 0;
+	}
 
 out_unlock:
 	xfs_iunlock_map_shared(ip, lock);
@@ -1372,6 +1383,15 @@ xfs_seek_hole(
 	}
 
 out:
+	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
+		error = EINVAL;
+		goto out_unlock;
+	}
+	if (offset > inode->i_sb->s_maxbytes) {
+		error = EINVAL;
+		goto out_unlock;
+	}
+
 	/*
 	 * At this point, we must have found a hole.  However, the returned
 	 * offset may be bigger than the file size as it may be aligned to
@@ -1379,8 +1399,10 @@ out:
 	 * situation in particular.
 	 */
 	offset = min_t(loff_t, offset, isize);
-	if (offset != file->f_pos)
+	if (offset != file->f_pos) {
 		file->f_pos = offset;
+		file->f_version = 0;
+	}
 
 out_unlock:
 	xfs_iunlock_map_shared(ip, lock);
-- 
1.7.9.5