Date: Wed, 29 Aug 2012 15:50:09 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r239845 - stable/9/sys/fs/nfsclient Message-ID: <201208291550.q7TFo9mQ071260@svn.freebsd.org>
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Author: kib Date: Wed Aug 29 15:50:09 2012 New Revision: 239845 URL: http://svn.freebsd.org/changeset/base/239845 Log: MFC r236687: Improve handling of uiomove(9) errors for the NFS client. Modified: stable/9/sys/fs/nfsclient/nfs_clbio.c Directory Properties: stable/9/sys/ (props changed) stable/9/sys/fs/ (props changed) Modified: stable/9/sys/fs/nfsclient/nfs_clbio.c ============================================================================== --- stable/9/sys/fs/nfsclient/nfs_clbio.c Wed Aug 29 15:46:01 2012 (r239844) +++ stable/9/sys/fs/nfsclient/nfs_clbio.c Wed Aug 29 15:50:09 2012 (r239845) @@ -873,8 +873,9 @@ ncl_write(struct vop_write_args *ap) struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr_t lbn; int bcount; - int n, on, error = 0; - off_t tmp_off; + int bp_cached, n, on, error = 0; + size_t orig_resid, local_resid; + off_t orig_size, tmp_off; KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode")); KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, @@ -926,6 +927,11 @@ flush_and_restart: mtx_unlock(&np->n_mtx); } + orig_resid = uio->uio_resid; + mtx_lock(&np->n_mtx); + orig_size = np->n_size; + mtx_unlock(&np->n_mtx); + /* * If IO_APPEND then load uio_offset. We restart here if we cannot * get the append lock. @@ -1103,7 +1109,10 @@ again: * normally. */ + bp_cached = 1; if (on == 0 && n == bcount) { + if ((bp->b_flags & B_CACHE) == 0) + bp_cached = 0; bp->b_flags |= B_CACHE; bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; @@ -1169,8 +1178,24 @@ again: goto again; } + local_resid = uio->uio_resid; error = uiomove((char *)bp->b_data + on, n, uio); + if (error != 0 && !bp_cached) { + /* + * This block has no other content then what + * possibly was written by the faulty uiomove. + * Release it, forgetting the data pages, to + * prevent the leak of uninitialized data to + * usermode. + */ + bp->b_ioflags |= BIO_ERROR; + brelse(bp); + uio->uio_offset -= local_resid - uio->uio_resid; + uio->uio_resid = local_resid; + break; + } + /* * Since this block is being modified, it must be written * again and not just committed. Since write clustering does @@ -1179,17 +1204,18 @@ again: */ bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); - if (error) { - bp->b_ioflags |= BIO_ERROR; - brelse(bp); - break; - } + /* + * Get the partial update on the progress made from + * uiomove, if an error occured. + */ + if (error != 0) + n = local_resid - uio->uio_resid; /* * Only update dirtyoff/dirtyend if not a degenerate * condition. */ - if (n) { + if (n > 0) { if (bp->b_dirtyend > 0) { bp->b_dirtyoff = min(on, bp->b_dirtyoff); bp->b_dirtyend = max((on + n), bp->b_dirtyend); @@ -1218,8 +1244,22 @@ again: } else { bdwrite(bp); } + + if (error != 0) + break; } while (uio->uio_resid > 0 && n > 0); + if (error != 0) { + if (ioflag & IO_UNIT) { + VATTR_NULL(&vattr); + vattr.va_size = orig_size; + /* IO_SYNC is handled implicitely */ + (void)VOP_SETATTR(vp, &vattr, cred); + uio->uio_offset -= orig_resid - uio->uio_resid; + uio->uio_resid = orig_resid; + } + } + return (error); }
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