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author | Pawel Jakub Dawidek <pjd@FreeBSD.org> | 2010-08-28 08:57:15 +0000 |
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committer | Pawel Jakub Dawidek <pjd@FreeBSD.org> | 2010-08-28 08:57:15 +0000 |
commit | c87f1ad43ce664de499084f7662dd59b1c180eff (patch) | |
tree | 5216e09d1d3ceb4e2984d034b547bc157ff7fbb3 /sys | |
parent | 4d02a00a57d8ce2bd81efc6c9b65ab7ce241bc5e (diff) | |
download | src-c87f1ad43ce664de499084f7662dd59b1c180eff.tar.gz src-c87f1ad43ce664de499084f7662dd59b1c180eff.zip |
There is a bug in vfs_allocate_syncvnode() failure handling in mount code.
Actually it is hard to properly handle such a failure, especially in MNT_UPDATE
case. The only reason for the vfs_allocate_syncvnode() function to fail is
getnewvnode() failure. Fortunately it is impossible for current implementation
of getnewvnode() to fail, so we can assert this and make
vfs_allocate_syncvnode() void. This in turn free us from handling its failures
in the mount code.
Reviewed by: kib
MFC after: 1 month
Notes
Notes:
svn path=/head/; revision=211930
Diffstat (limited to 'sys')
-rw-r--r-- | sys/kern/vfs_mount.c | 8 | ||||
-rw-r--r-- | sys/kern/vfs_subr.c | 12 | ||||
-rw-r--r-- | sys/sys/mount.h | 2 |
3 files changed, 9 insertions, 13 deletions
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index 088d93973bd7..fe9f16c33555 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -1036,7 +1036,7 @@ vfs_domount( MNT_IUNLOCK(mp); if ((mp->mnt_flag & MNT_RDONLY) == 0) { if (mp->mnt_syncer == NULL) - error = vfs_allocate_syncvnode(mp); + vfs_allocate_syncvnode(mp); } else { if (mp->mnt_syncer != NULL) vrele(mp->mnt_syncer); @@ -1078,10 +1078,8 @@ vfs_domount( mountcheckdirs(vp, newdp); vrele(newdp); if ((mp->mnt_flag & MNT_RDONLY) == 0) - error = vfs_allocate_syncvnode(mp); + vfs_allocate_syncvnode(mp); vfs_unbusy(mp); - if (error) - vrele(vp); } else { vfs_unbusy(mp); vfs_mount_destroy(mp); @@ -1311,7 +1309,7 @@ dounmount(mp, flags, td) mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ; if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) { MNT_IUNLOCK(mp); - (void) vfs_allocate_syncvnode(mp); + vfs_allocate_syncvnode(mp); MNT_ILOCK(mp); } mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index 985d73bc54fb..9bb365fcaae6 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -3365,7 +3365,7 @@ static struct vop_vector sync_vnodeops = { /* * Create a new filesystem syncer vnode for the specified mount point. */ -int +void vfs_allocate_syncvnode(struct mount *mp) { struct vnode *vp; @@ -3374,16 +3374,15 @@ vfs_allocate_syncvnode(struct mount *mp) int error; /* Allocate a new vnode */ - if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) { - mp->mnt_syncer = NULL; - return (error); - } + error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); + if (error != 0) + panic("vfs_allocate_syncvnode: getnewvnode() failed"); vp->v_type = VNON; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_vflag |= VV_FORCEINSMQ; error = insmntque(vp, mp); if (error != 0) - panic("vfs_allocate_syncvnode: insmntque failed"); + panic("vfs_allocate_syncvnode: insmntque() failed"); vp->v_vflag &= ~VV_FORCEINSMQ; VOP_UNLOCK(vp, 0); /* @@ -3411,7 +3410,6 @@ vfs_allocate_syncvnode(struct mount *mp) mtx_unlock(&sync_mtx); BO_UNLOCK(bo); mp->mnt_syncer = vp; - return (0); } /* diff --git a/sys/sys/mount.h b/sys/sys/mount.h index 20dcf641c7bd..85f16ff28020 100644 --- a/sys/sys/mount.h +++ b/sys/sys/mount.h @@ -730,7 +730,7 @@ void vfs_msync(struct mount *, int); int vfs_busy(struct mount *, int); int vfs_export /* process mount export info */ (struct mount *, struct export_args *); -int vfs_allocate_syncvnode(struct mount *); +void vfs_allocate_syncvnode(struct mount *); int vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions); void vfs_getnewfsid(struct mount *); struct cdev *vfs_getrootfsid(struct mount *); |