Module Name: src Committed By: reinoud Date: Wed Dec 22 14:05:51 UTC 2010
Modified Files: src/sys/kern: vfs_bio.c Log Message: Fix nestio's behavior on error. The mbp->b_resid is used to track if all the nested buffers have been issued and reported back. When the last buffer calls in, mbp->b_resid becomes zero and biodone(mbp) is called. This is fine as long as there are no errors. If a read-error does occure in one of the nested buffers, the mbp->b_error is set and on its call to biodone(mbp), with mbp->b_resid is zero, physio() panics since it asserts that IF an error is set on a buffer, there should be a residual amount of data left to transfered. The patch fixes this case by setting mbp->b_resid back to mbp->b_bcount on mbp->b_error just before biodone(mbp). This behaviour is consistent with normal buffer issueing. It either succeeds or doesn't succeed. To generate a diff of this commit: cvs rdiff -u -r1.225 -r1.226 src/sys/kern/vfs_bio.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.