From owner-svn-src-head@FreeBSD.ORG Tue Apr 15 15:41:58 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8B26F3F1; Tue, 15 Apr 2014 15:41:58 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 77C881A10; Tue, 15 Apr 2014 15:41:58 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s3FFfwbx000644; Tue, 15 Apr 2014 15:41:58 GMT (envelope-from marcel@svn.freebsd.org) Received: (from marcel@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s3FFfwDA000643; Tue, 15 Apr 2014 15:41:58 GMT (envelope-from marcel@svn.freebsd.org) Message-Id: <201404151541.s3FFfwDA000643@svn.freebsd.org> From: Marcel Moolenaar Date: Tue, 15 Apr 2014 15:41:58 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r264504 - head/sys/geom/uzip X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Apr 2014 15:41:58 -0000 Author: marcel Date: Tue Apr 15 15:41:57 2014 New Revision: 264504 URL: http://svnweb.freebsd.org/changeset/base/264504 Log: Make sure not to do I/O for more than MAXPHYS bytes. Doing so can cause problems in our providers, such as a KASSERT in md(4). We can initiate I/O for more than MAXPHYS bytes if we've been given a BIO for MAXPHYS bytes, the blocks from which we're reading couldn't be compressed and we had compression in preceeding blocks resulting in misalignment of the blocks we're trying to read relative to the sector. We're forced to round up the I/O length to make it an multiple of the sector size. When we detect the condition, we'll reduce the block count and perform a "short" read. In g_uzip_done() we need to consider the original I/O length and stop early if we're about to deflate a block that we didn't read. By using bio_completed in the cloned BIO and not bio_length to check for this, we automatically and gracefully handle short reads that our providers may be doing on top of the short reads we may initiate ourselves. Obtained from: Juniper Networks, Inc. Modified: head/sys/geom/uzip/g_uzip.c Modified: head/sys/geom/uzip/g_uzip.c ============================================================================== --- head/sys/geom/uzip/g_uzip.c Tue Apr 15 15:20:37 2014 (r264503) +++ head/sys/geom/uzip/g_uzip.c Tue Apr 15 15:41:57 2014 (r264504) @@ -125,7 +125,7 @@ g_uzip_done(struct bio *bp) struct g_consumer *cp; struct g_geom *gp; struct g_uzip_softc *sc; - off_t pos, upos; + off_t iolen, pos, upos; uint32_t start_blk, i; size_t bsize; @@ -153,11 +153,13 @@ g_uzip_done(struct bio *bp) } start_blk = bp2->bio_offset / sc->blksz; bsize = pp2->sectorsize; + iolen = bp->bio_completed; pos = sc->offsets[start_blk] % bsize; upos = 0; - DPRINTF(("%s: done: start_blk %d, pos %jd, upos %jd (%jd, %d, %zd)\n", + DPRINTF(("%s: done: start_blk %d, pos %jd, upos %jd, iolen %jd " + "(%jd, %d, %zd)\n", gp->name, start_blk, (intmax_t)pos, (intmax_t)upos, - (intmax_t)bp2->bio_offset, sc->blksz, bsize)); + (intmax_t)iolen, (intmax_t)bp2->bio_offset, sc->blksz, bsize)); for (i = start_blk; upos < bp2->bio_length; i++) { off_t len, ulen, uoff; @@ -172,6 +174,12 @@ g_uzip_done(struct bio *bp) bp2->bio_completed += ulen; continue; } + if (len > iolen) { + DPRINTF(("%s: done: early termination: len (%jd) > " + "iolen (%jd)\n", + gp->name, (intmax_t)len, (intmax_t)iolen)); + break; + } zs.next_in = bp->bio_data + pos; zs.avail_in = len; zs.next_out = sc->last_buf; @@ -196,6 +204,7 @@ g_uzip_done(struct bio *bp) mtx_unlock(&sc->last_mtx); pos += len; + iolen -= len; upos += ulen; bp2->bio_completed += ulen; err = inflateReset(&zs); @@ -290,8 +299,16 @@ g_uzip_start(struct bio *bp) pp2->name, pp2->sectorsize, (intmax_t)pp2->mediasize)); bsize = pp2->sectorsize; bp2->bio_offset = sc->offsets[start_blk] - sc->offsets[start_blk] % bsize; - bp2->bio_length = sc->offsets[end_blk] - bp2->bio_offset; - bp2->bio_length = (bp2->bio_length + bsize - 1) / bsize * bsize; + while (1) { + bp2->bio_length = sc->offsets[end_blk] - bp2->bio_offset; + bp2->bio_length = (bp2->bio_length + bsize - 1) / bsize * bsize; + if (bp2->bio_length < MAXPHYS) + break; + + end_blk--; + DPRINTF(("%s: bio_length (%jd) > MAXPHYS: lowering end_blk " + "to %u\n", gp->name, (intmax_t)bp2->bio_length, end_blk)); + } DPRINTF(("%s: start %jd + %jd -> %ju + %ju -> %jd + %jd\n", gp->name, (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length,