xfs: factor out buffer I/O failure code

We use the same buffer I/O failure code in a few different places. It's not much code, but it's not necessarily self-explanatory. Factor it into a helper and document it in one place. Signed-off-by: Brian Foster <[email protected]> Reviewed-by: Allison Collins <[email protected]> Reviewed-by: Dave Chinner <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]>
torvalds · May 7, 2020 · 54b3b1f · 54b3b1f
1 parent cb6ad09
commit 54b3b1f
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Showing 4 changed files with 22 additions and 27 deletions.
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
@@ -1248,6 +1248,22 @@ xfs_buf_ioerror_alert(
  -bp->b_error);
 }
 
+/*
+ * To simulate an I/O failure, the buffer must be locked and held with at least
+ * three references. The LRU reference is dropped by the stale call. The buf
+ * item reference is dropped via ioend processing. The third reference is owned
+ * by the caller and is dropped on I/O completion if the buffer is XBF_ASYNC.
+ */
+void
+xfs_buf_ioend_fail(
+ struct xfs_buf *bp)
+{
+ bp->b_flags &= ~XBF_DONE;
+ xfs_buf_stale(bp);
+ xfs_buf_ioerror(bp, -EIO);
+ xfs_buf_ioend(bp);
+}
+
 int
 xfs_bwrite(
  struct xfs_buf *bp)
@@ -1480,10 +1496,7 @@ __xfs_buf_submit(
 
  /* on shutdown we stale and complete the buffer immediately */
  if (XFS_FORCED_SHUTDOWN(bp->b_mount)) {
- xfs_buf_ioerror(bp, -EIO);
- bp->b_flags &= ~XBF_DONE;
- xfs_buf_stale(bp);
- xfs_buf_ioend(bp);
+ xfs_buf_ioend_fail(bp);
  return -EIO;
  }
 

diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
@@ -263,6 +263,7 @@ extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
  xfs_failaddr_t failaddr);
 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
 extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
+void xfs_buf_ioend_fail(struct xfs_buf *);
 
 extern int __xfs_buf_submit(struct xfs_buf *bp, bool);
 static inline int xfs_buf_submit(struct xfs_buf *bp)

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
@@ -471,28 +471,13 @@ xfs_buf_item_unpin(
  xfs_buf_relse(bp);
  } else if (freed && remove) {
  /*
- * There are currently two references to the buffer - the active
- * LRU reference and the buf log item. What we are about to do
- * here - simulate a failed IO completion - requires 3
- * references.
- *
- * The LRU reference is removed by the xfs_buf_stale() call. The
- * buf item reference is removed by the xfs_buf_iodone()
- * callback that is run by xfs_buf_do_callbacks() during ioend
- * processing (via the bp->b_iodone callback), and then finally
- * the ioend processing will drop the IO reference if the buffer
- * is marked XBF_ASYNC.
- *
- * Hence we need to take an additional reference here so that IO
- * completion processing doesn't free the buffer prematurely.
+ * The buffer must be locked and held by the caller to simulate
+ * an async I/O failure.
  */
  xfs_buf_lock(bp);
  xfs_buf_hold(bp);
  bp->b_flags |= XBF_ASYNC;
- xfs_buf_ioerror(bp, -EIO);
- bp->b_flags &= ~XBF_DONE;
- xfs_buf_stale(bp);
- xfs_buf_ioend(bp);
+ xfs_buf_ioend_fail(bp);
  }
 }
 

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
@@ -3630,11 +3630,7 @@ xfs_iflush_cluster(
  */
  ASSERT(bp->b_iodone);
  bp->b_flags |= XBF_ASYNC;
- bp->b_flags &= ~XBF_DONE;
- xfs_buf_stale(bp);
- xfs_buf_ioerror(bp, -EIO);
- xfs_buf_ioend(bp);
-
+ xfs_buf_ioend_fail(bp);
  xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
 
  /* abort the corrupt inode, as it was not attached to the buffer */