Module Name: src Committed By: riz Date: Mon Apr 16 15:37:12 UTC 2012
Modified Files: src/sys/fs/msdosfs [netbsd-6]: msdosfs_fat.c Log Message: Pull up following revision(s) (requested by hannken in ticket #183): sys/fs/msdosfs/msdosfs_fat.c: revision 1.20 pcbmap(): We cannot use bread() here as for the pagedaemon getblk() may fail leading to a panic in bread(). Replace bread() with getblk() / VOP_STRATEGY() and return an error if getblk() fails. Fixes PR#46282: 6.0_BETA crash: msdosfs_bmap -> pcbmap -> bread -> bio_doread This is an interim solution for easy pullup. The final solution is be to change bread() to not return a buffer on error. As we have to change all callers of bread() this will not qualify for a pullup. To generate a diff of this commit: cvs rdiff -u -r1.19 -r1.19.18.1 src/sys/fs/msdosfs/msdosfs_fat.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/fs/msdosfs/msdosfs_fat.c diff -u src/sys/fs/msdosfs/msdosfs_fat.c:1.19 src/sys/fs/msdosfs/msdosfs_fat.c:1.19.18.1 --- src/sys/fs/msdosfs/msdosfs_fat.c:1.19 Tue Jan 26 20:25:52 2010 +++ src/sys/fs/msdosfs/msdosfs_fat.c Mon Apr 16 15:37:12 2012 @@ -1,4 +1,4 @@ -/* $NetBSD: msdosfs_fat.c,v 1.19 2010/01/26 20:25:52 joerg Exp $ */ +/* $NetBSD: msdosfs_fat.c,v 1.19.18.1 2012/04/16 15:37:12 riz Exp $ */ /*- * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. @@ -48,7 +48,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: msdosfs_fat.c,v 1.19 2010/01/26 20:25:52 joerg Exp $"); +__KERNEL_RCSID(0, "$NetBSD: msdosfs_fat.c,v 1.19.18.1 2012/04/16 15:37:12 riz Exp $"); /* * kernel include files. @@ -254,11 +254,26 @@ pcbmap(struct denode *dep, u_long findcn if (bn != bp_bn) { if (bp) brelse(bp, 0); - error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn), bsize, - NOCRED, 0, &bp); - if (error) { - brelse(bp, 0); - return (error); + bp = getblk(pmp->pm_devvp, de_bn2kb(pmp, bn), bsize, + 0, 0); + if (bp == NULL) { + /* + * getblk() above returns NULL only iff we are + * pagedaemon. See the implementation of getblk + * for detail. + */ + return ENOMEM; + } + if (!ISSET(bp->b_oflags, (BO_DONE | BO_DELWRI))) { + SET(bp->b_flags, B_READ); + BIO_SETPRIO(bp, BPRIO_TIMECRITICAL); + VOP_STRATEGY(pmp->pm_devvp, bp); + curlwp->l_ru.ru_inblock++; + error = biowait(bp); + if (error) { + brelse(bp, 0); + return error; + } } bp_bn = bn; }