Merge tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs

Pull xfs bug fixes from Dave Chinner:
 "The fixes are for data corruption issues, memory corruption and
  regressions for changes merged in -rc1.

  Data corruption fixes:
   - fix a bunch of delayed allocation state mismatches
   - fix collapse/zero range bugs
   - fix a direct IO block mapping bug @ EOF

  Other fixes:
   - fix a use after free on metadata IO error
   - fix a use after free on IO error during unmount
   - fix an incorrect error sign on direct IO write errors
   - add missing O_TMPFILE inode security context initialisation"

* tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs:
  xfs: fix tmpfile/selinux deadlock and initialize security
  xfs: fix buffer use after free on IO error
  xfs: wrong error sign conversion during failed DIO writes
  xfs: unmount does not wait for shutdown during unmount
  xfs: collapse range is delalloc challenged
  xfs: don't map ranges that span EOF for direct IO
  xfs: zeroing space needs to punch delalloc blocks
  xfs: xfs_vm_write_end truncates too much on failure
  xfs: write failure beyond EOF truncates too much data
  xfs: kill buffers over failed write ranges properly

1 files changed, 12 insertions, 4 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 107f2fdfe41..cb10a0aaab3 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1372,21 +1372,29 @@ xfs_buf_iorequest(
 		xfs_buf_wait_unpin(bp);
 	xfs_buf_hold(bp);
 
-	/* Set the count to 1 initially, this will stop an I/O
+	/*
+	 * Set the count to 1 initially, this will stop an I/O
 	 * completion callout which happens before we have started
 	 * all the I/O from calling xfs_buf_ioend too early.
 	 */
 	atomic_set(&bp->b_io_remaining, 1);
 	_xfs_buf_ioapply(bp);
-	_xfs_buf_ioend(bp, 1);
+	/*
+	 * If _xfs_buf_ioapply failed, we'll get back here with
+	 * only the reference we took above.  _xfs_buf_ioend will
+	 * drop it to zero, so we'd better not queue it for later,
+	 * or we'll free it before it's done.
+	 */
+	_xfs_buf_ioend(bp, bp->b_error ? 0 : 1);
 
 	xfs_buf_rele(bp);
 }
 
 /*
  * Waits for I/O to complete on the buffer supplied.  It returns immediately if
- * no I/O is pending or there is already a pending error on the buffer.  It
- * returns the I/O error code, if any, or 0 if there was no error.
+ * no I/O is pending or there is already a pending error on the buffer, in which
+ * case nothing will ever complete.  It returns the I/O error code, if any, or
+ * 0 if there was no error.
  */
 int
 xfs_buf_iowait(