Differential D2602 Diff 5514 sys/kern/vfs_cache.c

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sys/kern/vfs_cache.c

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SYSCTL_OPAQUE(_vfs_cache, OID_AUTO, nchstats, CTLFLAG_RD \| CTLFLAG_MPSAFE,		SYSCTL_OPAQUE(_vfs_cache, OID_AUTO, nchstats, CTLFLAG_RD \| CTLFLAG_MPSAFE,
&nchstats, sizeof(nchstats), "LU",		&nchstats, sizeof(nchstats), "LU",
"VFS cache effectiveness statistics");		"VFS cache effectiveness statistics");



static void cache_zap(struct namecache *ncp);		static void cache_zap(struct namecache *ncp);
static int vn_vptocnp_locked(struct vnode *vp, struct ucred cred, char *buf,		static int vn_vptocnp_locked(struct vnode *vp, struct ucred cred,
u_int *buflen);		int lkflags, char buf, u_int buflen);
static int vn_fullpath1(struct thread td, struct vnode vp, struct vnode *rdir,		static int vn_fullpath1(struct thread td, struct vnode vp, struct vnode *rdir,
char buf, char *retbuf, u_int buflen);		int lkflags, char buf, char *retbuf, u_int buflen);

static MALLOC_DEFINE(M_VFSCACHE, "vfscache", "VFS name cache entries");		static MALLOC_DEFINE(M_VFSCACHE, "vfscache", "VFS name cache entries");

#ifdef DIAGNOSTIC		#ifdef DIAGNOSTIC
/*		/*
* Grab an atomic snapshot of the name cache hash chain lengths		* Grab an atomic snapshot of the name cache hash chain lengths
*/		*/
static SYSCTL_NODE(_debug, OID_AUTO, hashstat, CTLFLAG_RW, NULL,		static SYSCTL_NODE(_debug, OID_AUTO, hashstat, CTLFLAG_RW, NULL,
▲ Show 20 Lines • Show All 755 Lines • ▼ Show 20 Lines	kern___getcwd(struct thread td, char buf, enum uio_seg bufseg, u_int buflen,
tmpbuf = malloc(buflen, M_TEMP, M_WAITOK);		tmpbuf = malloc(buflen, M_TEMP, M_WAITOK);
fdp = td->td_proc->p_fd;		fdp = td->td_proc->p_fd;
FILEDESC_SLOCK(fdp);		FILEDESC_SLOCK(fdp);
cdir = fdp->fd_cdir;		cdir = fdp->fd_cdir;
VREF(cdir);		VREF(cdir);
rdir = fdp->fd_rdir;		rdir = fdp->fd_rdir;
VREF(rdir);		VREF(rdir);
FILEDESC_SUNLOCK(fdp);		FILEDESC_SUNLOCK(fdp);
error = vn_fullpath1(td, cdir, rdir, tmpbuf, &bp, buflen);		error = vn_fullpath1(td, cdir, rdir, 0, tmpbuf, &bp, buflen);
vrele(rdir);		vrele(rdir);
vrele(cdir);		vrele(cdir);

if (!error) {		if (!error) {
if (bufseg == UIO_SYSSPACE)		if (bufseg == UIO_SYSSPACE)
bcopy(bp, buf, strlen(bp) + 1);		bcopy(bp, buf, strlen(bp) + 1);
else		else
error = copyout(bp, buf, strlen(bp) + 1);		error = copyout(bp, buf, strlen(bp) + 1);
Show All 27 Lines
STATNODE(numfullpathfail4, "Number of fullpath search errors (ENOMEM)");		STATNODE(numfullpathfail4, "Number of fullpath search errors (ENOMEM)");
STATNODE(numfullpathfound, "Number of successful fullpath calls");		STATNODE(numfullpathfound, "Number of successful fullpath calls");

/*		/*
* Retrieve the full filesystem path that correspond to a vnode from the name		* Retrieve the full filesystem path that correspond to a vnode from the name
* cache (if available)		* cache (if available)
*/		*/
int		int
vn_fullpath(struct thread td, struct vnode vn, char retbuf, char freebuf)		vn_fullpath(struct thread td, struct vnode vn, int lkflags, char **retbuf,
		char **freebuf)
{		{
char *buf;		char *buf;
struct filedesc *fdp;		struct filedesc *fdp;
struct vnode *rdir;		struct vnode *rdir;
int error;		int error;

		KASSERT((lkflags & ~LK_NOWAIT) == 0,
		("invalid lkflags: %08x", lkflags));

if (disablefullpath)		if (disablefullpath)
return (ENODEV);		return (ENODEV);
if (vn == NULL)		if (vn == NULL)
return (EINVAL);		return (EINVAL);

buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);		buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
fdp = td->td_proc->p_fd;		fdp = td->td_proc->p_fd;
FILEDESC_SLOCK(fdp);		FILEDESC_SLOCK(fdp);
rdir = fdp->fd_rdir;		rdir = fdp->fd_rdir;
VREF(rdir);		VREF(rdir);
FILEDESC_SUNLOCK(fdp);		FILEDESC_SUNLOCK(fdp);
error = vn_fullpath1(td, vn, rdir, buf, retbuf, MAXPATHLEN);		error = vn_fullpath1(td, vn, rdir, lkflags, buf, retbuf, MAXPATHLEN);
vrele(rdir);		vrele(rdir);

if (!error)		if (!error)
*freebuf = buf;		*freebuf = buf;
else		else
free(buf, M_TEMP);		free(buf, M_TEMP);
return (error);		return (error);
}		}
Show All 11 Lines	vn_fullpath_global(struct thread td, struct vnode vn,
char *buf;		char *buf;
int error;		int error;

if (disablefullpath)		if (disablefullpath)
return (ENODEV);		return (ENODEV);
if (vn == NULL)		if (vn == NULL)
return (EINVAL);		return (EINVAL);
buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);		buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
error = vn_fullpath1(td, vn, rootvnode, buf, retbuf, MAXPATHLEN);		error = vn_fullpath1(td, vn, rootvnode, 0, buf, retbuf, MAXPATHLEN);
if (!error)		if (!error)
*freebuf = buf;		*freebuf = buf;
else		else
free(buf, M_TEMP);		free(buf, M_TEMP);
return (error);		return (error);
}		}

int		int
vn_vptocnp(struct vnode *vp, struct ucred cred, char buf, u_int buflen)		vn_vptocnp(struct vnode *vp, struct ucred cred, char buf, u_int buflen)
{		{
int error;		int error;

CACHE_RLOCK();		CACHE_RLOCK();
error = vn_vptocnp_locked(vp, cred, buf, buflen);		error = vn_vptocnp_locked(vp, cred, 0, buf, buflen);
if (error == 0)		if (error == 0)
CACHE_RUNLOCK();		CACHE_RUNLOCK();
return (error);		return (error);
}		}

static int		static int
vn_vptocnp_locked(struct vnode *vp, struct ucred cred, char *buf,		vn_vptocnp_locked(struct vnode *vp, struct ucred cred, int lkflags,
u_int *buflen)		char buf, u_int buflen)
{		{
struct vnode *dvp;		struct vnode *dvp;
struct namecache *ncp;		struct namecache *ncp;
int error;		int error;

TAILQ_FOREACH(ncp, &((*vp)->v_cache_dst), nc_dst) {		TAILQ_FOREACH(ncp, &((*vp)->v_cache_dst), nc_dst) {
if ((ncp->nc_flag & NCF_ISDOTDOT) == 0)		if ((ncp->nc_flag & NCF_ISDOTDOT) == 0)
break;		break;
Show All 18 Lines	if (ncp != NULL) {
CACHE_RUNLOCK();		CACHE_RUNLOCK();
vrele(dvp);		vrele(dvp);
CACHE_RLOCK();		CACHE_RLOCK();
return (0);		return (0);
}		}
SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0, 0, 0);		SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0, 0, 0);

CACHE_RUNLOCK();		CACHE_RUNLOCK();
vn_lock(*vp, LK_SHARED \| LK_RETRY);
		lkflags \|= LK_SHARED;
		if ((lkflags & LK_NOWAIT) == 0)
		lkflags \|= LK_RETRY;
		error = vn_lock(*vp, lkflags);
		if (error)
		vrele(*vp);
		else {
error = VOP_VPTOCNP(*vp, &dvp, cred, buf, buflen);		error = VOP_VPTOCNP(*vp, &dvp, cred, buf, buflen);
vput(*vp);		vput(*vp);
		}
if (error) {		if (error) {
numfullpathfail2++;		numfullpathfail2++;
SDT_PROBE(vfs, namecache, fullpath, return, error, vp,		SDT_PROBE(vfs, namecache, fullpath, return, error, vp,
NULL, 0, 0);		NULL, 0, 0);
return (error);		return (error);
}		}

*vp = dvp;		*vp = dvp;
Show All 14 Lines	vn_vptocnp_locked(struct vnode *vp, struct ucred cred, int lkflags,
return (0);		return (0);
}		}

/*		/*
* The magic behind kern___getcwd() and vn_fullpath().		* The magic behind kern___getcwd() and vn_fullpath().
*/		*/
static int		static int
vn_fullpath1(struct thread td, struct vnode vp, struct vnode *rdir,		vn_fullpath1(struct thread td, struct vnode vp, struct vnode *rdir,
char buf, char *retbuf, u_int buflen)		int lkflags, char buf, char *retbuf, u_int buflen)
{		{
int error, slash_prefixed;		int error, slash_prefixed;
#ifdef KDTRACE_HOOKS		#ifdef KDTRACE_HOOKS
struct vnode *startvp = vp;		struct vnode *startvp = vp;
#endif		#endif
struct vnode *vp1;		struct vnode *vp1;

buflen--;		buflen--;
buf[buflen] = '\0';		buf[buflen] = '\0';
error = 0;		error = 0;
slash_prefixed = 0;		slash_prefixed = 0;

SDT_PROBE(vfs, namecache, fullpath, entry, vp, 0, 0, 0, 0);		SDT_PROBE(vfs, namecache, fullpath, entry, vp, 0, 0, 0, 0);
numfullpathcalls++;		numfullpathcalls++;
vref(vp);		vref(vp);
CACHE_RLOCK();		CACHE_RLOCK();
if (vp->v_type != VDIR) {		if (vp->v_type != VDIR) {
error = vn_vptocnp_locked(&vp, td->td_ucred, buf, &buflen);		error = vn_vptocnp_locked(&vp, td->td_ucred, lkflags, buf, &buflen);
if (error)		if (error)
return (error);		return (error);
if (buflen == 0) {		if (buflen == 0) {
CACHE_RUNLOCK();		CACHE_RUNLOCK();
vrele(vp);		vrele(vp);
return (ENOMEM);		return (ENOMEM);
}		}
buf[--buflen] = '/';		buf[--buflen] = '/';
Show All 21 Lines	if (vp->v_type != VDIR) {
CACHE_RUNLOCK();		CACHE_RUNLOCK();
vrele(vp);		vrele(vp);
numfullpathfail1++;		numfullpathfail1++;
error = ENOTDIR;		error = ENOTDIR;
SDT_PROBE(vfs, namecache, fullpath, return,		SDT_PROBE(vfs, namecache, fullpath, return,
error, vp, NULL, 0, 0);		error, vp, NULL, 0, 0);
break;		break;
}		}
error = vn_vptocnp_locked(&vp, td->td_ucred, buf, &buflen);		error = vn_vptocnp_locked(&vp, td->td_ucred, lkflags, buf, &buflen);
if (error)		if (error)
break;		break;
if (buflen == 0) {		if (buflen == 0) {
CACHE_RUNLOCK();		CACHE_RUNLOCK();
vrele(vp);		vrele(vp);
error = ENOMEM;		error = ENOMEM;
SDT_PROBE(vfs, namecache, fullpath, return, error,		SDT_PROBE(vfs, namecache, fullpath, return, error,
startvp, NULL, 0, 0);		startvp, NULL, 0, 0);
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