Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Don't try to reacquire root vnode if vflush() in smbfs_unmount() fails. 

This is potentially fragile, since the vnode may have been reclaimed
in vflush(), and used by different filesystem. This wouldn't actually
happen due to n_parent link to parent directory, but better safe
than sorry.

Since sm_root is only and strictly cache to speed up VFS_ROOT(),
it can be acquired/dropped any time. Rearrange code to not
require sm_root set, and change smbfs_root() back to set
sm_root if it's not set yet. smbfs_unmount() now only vrele()s
the root vnode if sm_root is set, and doesn't try reacquire it
if vflush() fails.

problem with vref() after vflush() pointed out by Bill Studenmund
This commit is contained in:
jdolecek 2003-02-26 20:21:40 +00:00
parent 4f88b74062
commit 88db5b512b
1 changed files with 27 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
sys/fs/smbfs/smbfs_vfsops.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: smbfs_vfsops.c,v 1.21 2003/02/26 18:16:37 jdolecek Exp $ */
/* $NetBSD: smbfs_vfsops.c,v 1.22 2003/02/26 20:21:40 jdolecek Exp $ */
/*
* Copyright (c) 2000-2001, Boris Popov
@ -35,7 +35,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: smbfs_vfsops.c,v 1.21 2003/02/26 18:16:37 jdolecek Exp $");
__KERNEL_RCSID(0, "$NetBSD: smbfs_vfsops.c,v 1.22 2003/02/26 20:21:40 jdolecek Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@ -184,10 +184,6 @@ smbfs_mount(struct mount *mp, const char *path, void *data,
ssp->ss_name);
vfs_getnewfsid(mp);
error = smbfs_setroot(mp);
if (error)
goto bad;
return (0);
bad:
@ -223,14 +219,14 @@ smbfs_unmount(struct mount *mp, int mntflags, struct proc *p)
#ifdef QUOTA
#endif
/* Drop the extra reference to root vnode. */
KASSERT(smp->sm_root != NULL && SMBTOV(smp->sm_root) != NULL);
if (smp->sm_root) {
vrele(SMBTOV(smp->sm_root));
smp->sm_root = NULL;
}
/* Flush all vnodes. */
if ((error = vflush(mp, NULLVP, flags)) != 0) {
vref(SMBTOV(smp->sm_root));
if ((error = vflush(mp, NULLVP, flags)) != 0)
return error;
}
smb_makescred(&scred, p, p->p_ucred);
smb_share_lock(smp->sm_share, 0);
@ -270,11 +266,20 @@ smbfs_setroot(struct mount *mp)
error = smbfs_nget(mp, NULL, "TheRooT", 7, &fattr, &vp);
if (error)
return error;
/*
* Someone might have already set sm_root while we slept
* in smb_lookup or malloc/getnewvnode.
*/
if (smp->sm_root)
vput(vp);
else {
vp->v_flag |= VROOT;
smp->sm_root = VTOSMB(vp);
/* Keep reference, but unlock */
VOP_UNLOCK(vp, 0);
}
return (0);
}
@ -287,6 +292,13 @@ smbfs_root(struct mount *mp, struct vnode **vpp)
{
struct smbmount *smp = VFSTOSMBFS(mp);
if (__predict_false(!smp->sm_root)) {
int error = smbfs_setroot(mp);
if (error)
return (error);
/* fallthrough */
}
KASSERT(smp->sm_root != NULL && SMBTOV(smp->sm_root) != NULL);
*vpp = SMBTOV(smp->sm_root);
return vget(*vpp, LK_EXCLUSIVE | LK_RETRY);
@ -358,8 +370,6 @@ smbfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p)
struct smb_cred scred;
int error = 0;
KASSERT(smp->sm_root != NULL);
sbp->f_iosize = SSTOVC(ssp)->vc_txmax; /* optimal transfer block size */
smb_makescred(&scred, p, p->p_ucred);