From: Dave Chinner Date: Tue, 12 Mar 2013 12:30:34 +0000 (+1100) Subject: xfs: ensure we capture IO errors correctly X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c163f9a1760229a95d04e37b332de7d5c1c225cd;p=linux-beck.git xfs: ensure we capture IO errors correctly Failed buffer readahead can leave the buffer in the cache marked with an error. Most callers that then issue a subsequent read on the buffer do not zero the b_error field out, and so we may incorectly detect an error during IO completion due to the stale error value left on the buffer. Avoid this problem by zeroing the error before IO submission. This ensures that the only IO errors that are detected those captured from are those captured from bio submission or completion. Signed-off-by: Dave Chinner Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 50eb603e0cc1..82b70bda9f47 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1336,6 +1336,12 @@ _xfs_buf_ioapply( int size; int i; + /* + * Make sure we capture only current IO errors rather than stale errors + * left over from previous use of the buffer (e.g. failed readahead). + */ + bp->b_error = 0; + if (bp->b_flags & XBF_WRITE) { if (bp->b_flags & XBF_SYNCIO) rw = WRITE_SYNC;