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Diffstat (limited to 'sys/kern/vfs_cache.c')
-rw-r--r--sys/kern/vfs_cache.c121
1 files changed, 94 insertions, 27 deletions
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index fff50248470a..0e5bfbbf5f6f 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -113,6 +113,12 @@ SYSCTL_ULONG(_debug, OID_AUTO, numcachepl, CTLFLAG_RD, &numcachepl, 0, "");
#endif
struct nchstats nchstats; /* cache effectiveness statistics */
+struct mtx cache_lock;
+MTX_SYSINIT(vfscache, &cache_lock, "Name Cache", MTX_DEF);
+
+#define CACHE_LOCK() mtx_lock(&cache_lock)
+#define CACHE_UNLOCK() mtx_unlock(&cache_lock)
+
/*
* UMA zones for the VFS cache.
*
@@ -166,7 +172,7 @@ SYSCTL_OPAQUE(_vfs_cache, OID_AUTO, nchstats, CTLFLAG_RD, &nchstats,
-static void cache_zap(struct namecache *ncp);
+static void cache_zap(struct namecache *ncp, int locked);
static MALLOC_DEFINE(M_VFSCACHE, "vfscache", "VFS name cache entries");
@@ -261,13 +267,19 @@ SYSCTL_PROC(_debug_hashstat, OID_AUTO, nchash, CTLTYPE_INT|CTLFLAG_RD,
* pointer to a vnode or if it is just a negative cache entry.
*/
static void
-cache_zap(ncp)
+cache_zap(ncp, locked)
struct namecache *ncp;
+ int locked;
{
+ struct vnode *vp;
+
+ vp = NULL;
+ if (!locked)
+ CACHE_LOCK();
LIST_REMOVE(ncp, nc_hash);
LIST_REMOVE(ncp, nc_src);
if (LIST_EMPTY(&ncp->nc_dvp->v_cache_src)) {
- vdrop(ncp->nc_dvp);
+ vp = ncp->nc_dvp;
numcachehv--;
}
if (ncp->nc_vp) {
@@ -277,7 +289,12 @@ cache_zap(ncp)
numneg--;
}
numcache--;
+ CACHE_UNLOCK();
cache_free(ncp);
+ if (vp)
+ vdrop(vp);
+ if (locked)
+ CACHE_LOCK();
}
/*
@@ -294,15 +311,21 @@ int
cache_leaf_test(struct vnode *vp)
{
struct namecache *ncpc;
+ int leaf;
+ leaf = 0;
+ CACHE_LOCK();
for (ncpc = LIST_FIRST(&vp->v_cache_src);
ncpc != NULL;
ncpc = LIST_NEXT(ncpc, nc_src)
- ) {
- if (ncpc->nc_vp != NULL && ncpc->nc_vp->v_type == VDIR)
- return(-1);
+ ) {
+ if (ncpc->nc_vp != NULL && ncpc->nc_vp->v_type == VDIR) {
+ leaf = -1;
+ break;
+ }
}
- return(0);
+ CACHE_UNLOCK();
+ return (leaf);
}
/*
@@ -330,12 +353,14 @@ cache_lookup(dvp, vpp, cnp)
return (0);
}
+ CACHE_LOCK();
numcalls++;
if (cnp->cn_nameptr[0] == '.') {
if (cnp->cn_namelen == 1) {
*vpp = dvp;
dothits++;
+ CACHE_UNLOCK();
return (-1);
}
if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.') {
@@ -343,9 +368,11 @@ cache_lookup(dvp, vpp, cnp)
if (dvp->v_dd->v_id != dvp->v_ddid ||
(cnp->cn_flags & MAKEENTRY) == 0) {
dvp->v_ddid = 0;
+ CACHE_UNLOCK();
return (0);
}
*vpp = dvp->v_dd;
+ CACHE_UNLOCK();
return (-1);
}
}
@@ -367,6 +394,7 @@ cache_lookup(dvp, vpp, cnp)
nummiss++;
}
nchstats.ncs_miss++;
+ CACHE_UNLOCK();
return (0);
}
@@ -374,7 +402,8 @@ cache_lookup(dvp, vpp, cnp)
if ((cnp->cn_flags & MAKEENTRY) == 0) {
numposzaps++;
nchstats.ncs_badhits++;
- cache_zap(ncp);
+ CACHE_UNLOCK();
+ cache_zap(ncp, 0);
return (0);
}
@@ -383,6 +412,7 @@ cache_lookup(dvp, vpp, cnp)
numposhits++;
nchstats.ncs_goodhits++;
*vpp = ncp->nc_vp;
+ CACHE_UNLOCK();
return (-1);
}
@@ -390,7 +420,8 @@ cache_lookup(dvp, vpp, cnp)
if (cnp->cn_nameiop == CREATE) {
numnegzaps++;
nchstats.ncs_badhits++;
- cache_zap(ncp);
+ CACHE_UNLOCK();
+ cache_zap(ncp, 0);
return (0);
}
@@ -406,6 +437,7 @@ cache_lookup(dvp, vpp, cnp)
nchstats.ncs_neghits++;
if (ncp->nc_flag & NCF_WHITE)
cnp->cn_flags |= ISWHITEOUT;
+ CACHE_UNLOCK();
return (ENOENT);
}
@@ -421,6 +453,8 @@ cache_enter(dvp, vp, cnp)
struct namecache *ncp;
struct nchashhead *ncpp;
u_int32_t hash;
+ int hold;
+ int zap;
int len;
if (!doingcache)
@@ -442,8 +476,10 @@ cache_enter(dvp, vp, cnp)
}
}
+ hold = 0;
+ zap = 0;
ncp = cache_alloc(cnp->cn_namelen);
- /* XXX can uma_zalloc(..., M_WAITOK) fail? */
+ CACHE_LOCK();
numcache++;
if (!vp) {
numneg++;
@@ -467,7 +503,7 @@ cache_enter(dvp, vp, cnp)
ncpp = NCHHASH(hash);
LIST_INSERT_HEAD(ncpp, ncp, nc_hash);
if (LIST_EMPTY(&dvp->v_cache_src)) {
- vhold(dvp);
+ hold = 1;
numcachehv++;
}
LIST_INSERT_HEAD(&dvp->v_cache_src, ncp, nc_src);
@@ -483,8 +519,13 @@ cache_enter(dvp, vp, cnp)
}
if (numneg * ncnegfactor > numcache) {
ncp = TAILQ_FIRST(&ncneg);
- cache_zap(ncp);
+ zap = 1;
}
+ CACHE_UNLOCK();
+ if (hold)
+ vhold(dvp);
+ if (zap)
+ cache_zap(ncp, 0);
}
/*
@@ -522,16 +563,21 @@ SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nchinit, NULL)
* XXX: using the global v_id.
*/
+/*
+ * XXX This is sometimes called when a vnode may still be re-used, in which
+ * case v_dd may be invalid. Need to look this up.
+ */
void
cache_purge(vp)
struct vnode *vp;
{
static u_long nextid;
+ CACHE_LOCK();
while (!LIST_EMPTY(&vp->v_cache_src))
- cache_zap(LIST_FIRST(&vp->v_cache_src));
+ cache_zap(LIST_FIRST(&vp->v_cache_src), 1);
while (!TAILQ_EMPTY(&vp->v_cache_dst))
- cache_zap(TAILQ_FIRST(&vp->v_cache_dst));
+ cache_zap(TAILQ_FIRST(&vp->v_cache_dst), 1);
do
nextid++;
@@ -539,6 +585,7 @@ cache_purge(vp)
vp->v_id = nextid;
vp->v_dd = vp;
vp->v_ddid = 0;
+ CACHE_UNLOCK();
}
/*
@@ -553,16 +600,25 @@ cache_purgevfs(mp)
{
struct nchashhead *ncpp;
struct namecache *ncp, *nnp;
+ struct nchashhead mplist;
+
+ LIST_INIT(&mplist);
+ ncp = NULL;
/* Scan hash tables for applicable entries */
+ CACHE_LOCK();
for (ncpp = &nchashtbl[nchash]; ncpp >= nchashtbl; ncpp--) {
for (ncp = LIST_FIRST(ncpp); ncp != 0; ncp = nnp) {
nnp = LIST_NEXT(ncp, nc_hash);
if (ncp->nc_dvp->v_mount == mp) {
- cache_zap(ncp);
+ LIST_REMOVE(ncp, nc_hash);
+ LIST_INSERT_HEAD(&mplist, ncp, nc_hash);
}
}
}
+ CACHE_UNLOCK();
+ while (!LIST_EMPTY(&mplist))
+ cache_zap(LIST_FIRST(&mplist), 0);
}
/*
@@ -774,7 +830,6 @@ kern___getcwd(struct thread *td, u_char *buf, enum uio_seg bufseg, u_int buflen)
fdp = td->td_proc->p_fd;
slash_prefixed = 0;
FILEDESC_LOCK(fdp);
- mp_fixme("No vnode locking done!");
for (vp = fdp->fd_cdir; vp != fdp->fd_rdir && vp != rootvnode;) {
if (vp->v_vflag & VV_ROOT) {
if (vp->v_mount == NULL) { /* forced unmount */
@@ -791,37 +846,43 @@ kern___getcwd(struct thread *td, u_char *buf, enum uio_seg bufseg, u_int buflen)
free(tmpbuf, M_TEMP);
return (ENOTDIR);
}
+ CACHE_LOCK();
ncp = TAILQ_FIRST(&vp->v_cache_dst);
if (!ncp) {
- FILEDESC_UNLOCK(fdp);
numcwdfail2++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(tmpbuf, M_TEMP);
return (ENOENT);
}
if (ncp->nc_dvp != vp->v_dd) {
- FILEDESC_UNLOCK(fdp);
numcwdfail3++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(tmpbuf, M_TEMP);
return (EBADF);
}
for (i = ncp->nc_nlen - 1; i >= 0; i--) {
if (bp == tmpbuf) {
- FILEDESC_UNLOCK(fdp);
numcwdfail4++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(tmpbuf, M_TEMP);
return (ENOMEM);
}
*--bp = ncp->nc_name[i];
}
if (bp == tmpbuf) {
- FILEDESC_UNLOCK(fdp);
numcwdfail4++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(tmpbuf, M_TEMP);
return (ENOMEM);
}
*--bp = '/';
slash_prefixed = 1;
vp = vp->v_dd;
+ CACHE_UNLOCK();
}
FILEDESC_UNLOCK(fdp);
if (!slash_prefixed) {
@@ -884,9 +945,9 @@ vn_fullpath(struct thread *td, struct vnode *vn, char **retbuf, char **freebuf)
*bp = '\0';
fdp = td->td_proc->p_fd;
slash_prefixed = 0;
+ ASSERT_VOP_LOCKED(vn, "vn_fullpath");
FILEDESC_LOCK(fdp);
for (vp = vn; vp != fdp->fd_rdir && vp != rootvnode;) {
- ASSERT_VOP_LOCKED(vp, "vn_fullpath");
if (vp->v_vflag & VV_ROOT) {
if (vp->v_mount == NULL) { /* forced unmount */
FILEDESC_UNLOCK(fdp);
@@ -898,46 +959,52 @@ vn_fullpath(struct thread *td, struct vnode *vn, char **retbuf, char **freebuf)
}
if (vp != vn && vp->v_dd->v_id != vp->v_ddid) {
FILEDESC_UNLOCK(fdp);
- numfullpathfail1++;
free(buf, M_TEMP);
+ numfullpathfail1++;
return (ENOTDIR);
}
+ CACHE_LOCK();
ncp = TAILQ_FIRST(&vp->v_cache_dst);
if (!ncp) {
- FILEDESC_UNLOCK(fdp);
numfullpathfail2++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(buf, M_TEMP);
return (ENOENT);
}
if (vp != vn && ncp->nc_dvp != vp->v_dd) {
- FILEDESC_UNLOCK(fdp);
numfullpathfail3++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(buf, M_TEMP);
return (EBADF);
}
for (i = ncp->nc_nlen - 1; i >= 0; i--) {
if (bp == buf) {
- FILEDESC_UNLOCK(fdp);
numfullpathfail4++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(buf, M_TEMP);
return (ENOMEM);
}
*--bp = ncp->nc_name[i];
}
if (bp == buf) {
- FILEDESC_UNLOCK(fdp);
numfullpathfail4++;
+ CACHE_UNLOCK();
+ FILEDESC_UNLOCK(fdp);
free(buf, M_TEMP);
return (ENOMEM);
}
*--bp = '/';
slash_prefixed = 1;
vp = ncp->nc_dvp;
+ CACHE_UNLOCK();
}
if (!slash_prefixed) {
if (bp == buf) {
- FILEDESC_UNLOCK(fdp);
numfullpathfail4++;
+ FILEDESC_UNLOCK(fdp);
free(buf, M_TEMP);
return (ENOMEM);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-28 06:34:48 +0000