1 files changed, 26 insertions, 0 deletions

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index aa238c8fbd7a..8b6812f66a15 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -1838,6 +1838,12 @@ again:
 #endif
 }
 
+/*
+ * xfs_lock_two_inodes() can only be used to lock one type of lock
+ * at a time - the iolock or the ilock, but not both at once. If
+ * we lock both at once, lockdep will report false positives saying
+ * we have violated locking orders.
+ */
 void
 xfs_lock_two_inodes(
         xfs_inode_t             *ip0,
@@ -1848,6 +1854,8 @@ xfs_lock_two_inodes(
         int                     attempts = 0;
         xfs_log_item_t          *lp;
 
+        if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))
+                ASSERT((lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) == 0);
         ASSERT(ip0->i_ino != ip1->i_ino);
 
         if (ip0->i_ino > ip1->i_ino) {
@@ -3152,6 +3160,13 @@ error1:	/* Just cancel transaction */
 /*
  * Zero file bytes between startoff and endoff inclusive.
  * The iolock is held exclusive and no blocks are buffered.
+ *
+ * This function is used by xfs_free_file_space() to zero
+ * partial blocks when the range to free is not block aligned.
+ * When unreserving space with boundaries that are not block
+ * aligned we round up the start and round down the end
+ * boundaries and then use this function to zero the parts of
+ * the blocks that got dropped during the rounding.
  */
 STATIC int
 xfs_zero_remaining_bytes(
@@ -3168,6 +3183,17 @@ xfs_zero_remaining_bytes(
         int                     nimap;
         int                     error = 0;
 
+        /*
+         * Avoid doing I/O beyond eof - it's not necessary
+         * since nothing can read beyond eof.  The space will
+         * be zeroed when the file is extended anyway.
+         */
+        if (startoff >= ip->i_size)
+                return 0;
+
+        if (endoff > ip->i_size)
+                endoff = ip->i_size;
+
         bp = xfs_buf_get_noaddr(mp->m_sb.sb_blocksize,
                                 XFS_IS_REALTIME_INODE(ip) ?
                                 mp->m_rtdev_targp : mp->m_ddev_targp);