From: Joe Talbott <josepht@dragonflybsd.org>
Date: Tue, 7 Sep 2010 04:17:00 +0000 (-0400)
Subject: msdosfs - Fix panic when mounting msdos filesystems.
X-Git-Url: https://gitweb.dragonflybsd.org/~lentferj/dragonfly.git/commitdiff_plain/12d442975420e1da3daae44f5c20a3c1dce055df

msdosfs - Fix panic when mounting msdos filesystems.

bread()ing different sizes from the same address requires this
flag before b[q]relse() is called.

Discussed-With: dillon
---

diff --git a/sys/vfs/msdosfs/msdosfs_vfsops.c b/sys/vfs/msdosfs/msdosfs_vfsops.c
index f7abfc6929..743279d23e 100644
--- a/sys/vfs/msdosfs/msdosfs_vfsops.c
+++ b/sys/vfs/msdosfs/msdosfs_vfsops.c
@@ -522,6 +522,7 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
 	/*
 	 * Release the bootsector buffer.
 	 */
+	bp->b_flags |= B_RELBUF;
 	brelse(bp);
 	bp = NULL;
 
@@ -543,6 +544,7 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
 				pmp->pm_nxtfree = CLUST_FIRST;
 		} else
 			pmp->pm_fsinfo = 0;
+		bp->b_flags |= B_RELBUF;
 		brelse(bp);
 		bp = NULL;
 	}
@@ -605,8 +607,10 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
 	return 0;
 
 error_exit:
-	if (bp)
+	if (bp) {
+		bp->b_flags |= B_RELBUF;
 		brelse(bp);
+	}
 	VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE);
 	if (pmp) {
 		if (pmp->pm_inusemap)