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-rw-r--r--usr/src/uts/common/fs/mntfs/mntvnops.c84
-rw-r--r--usr/src/uts/common/sys/fs/mntdata.h10
2 files changed, 73 insertions, 21 deletions
diff --git a/usr/src/uts/common/fs/mntfs/mntvnops.c b/usr/src/uts/common/fs/mntfs/mntvnops.c
index dcfce13ab5..33a9561ee2 100644
--- a/usr/src/uts/common/fs/mntfs/mntvnops.c
+++ b/usr/src/uts/common/fs/mntfs/mntvnops.c
@@ -23,8 +23,6 @@
* Use is subject to license terms.
*/
-#pragma ident "%Z%%M% %I% %E% SMI"
-
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/atomic.h>
@@ -722,9 +720,11 @@ mntread(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cred, caller_context_t *ct)
size_t len = uio->uio_resid;
mntnode_t *mnp = VTOM(vp);
char *buf;
- mntsnap_t *snap = &mnp->mnt_read;
+ mntsnap_t *snap;
int datamodel;
+ rw_enter(&mnp->mnt_contents, RW_READER);
+ snap = &mnp->mnt_read;
if (off == (off_t)0 || snap->mnts_count == 0) {
/*
* It is assumed that any kernel callers wishing
@@ -738,17 +738,28 @@ mntread(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cred, caller_context_t *ct)
datamodel = DATAMODEL_LP64;
else
datamodel = get_udatamodel();
- if ((error = mntfs_snapshot(mnp, 1, datamodel)) != 0)
+ if (!rw_tryupgrade(&mnp->mnt_contents)) {
+ rw_exit(&mnp->mnt_contents);
+ rw_enter(&mnp->mnt_contents, RW_WRITER);
+ }
+ if ((error = mntfs_snapshot(mnp, 1, datamodel)) != 0) {
+ rw_exit(&mnp->mnt_contents);
return (error);
+ }
+ rw_downgrade(&mnp->mnt_contents);
}
if ((size_t)(off + len) > snap->mnts_textsize)
len = snap->mnts_textsize - off;
- if (off < 0 || len > snap->mnts_textsize)
+ if (off < 0 || len > snap->mnts_textsize) {
+ rw_exit(&mnp->mnt_contents);
return (EFAULT);
+ }
- if (len == 0)
+ if (len == 0) {
+ rw_exit(&mnp->mnt_contents);
return (0);
+ }
/*
* The mnttab image is stored in the user's address space,
@@ -763,6 +774,7 @@ mntread(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cred, caller_context_t *ct)
}
kmem_free(buf, len);
vfs_mnttab_readop();
+ rw_exit(&mnp->mnt_contents);
return (error);
}
@@ -776,9 +788,10 @@ mntgetattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
vnode_t *rvp;
extern timespec_t vfs_mnttab_ctime;
mntdata_t *mntdata = MTOD(VTOM(vp));
- mntsnap_t *snap = mnp->mnt_read.mnts_count ?
- &mnp->mnt_read : &mnp->mnt_ioctl;
+ mntsnap_t *snap;
+ rw_enter(&mnp->mnt_contents, RW_READER);
+ snap = mnp->mnt_read.mnts_count ? &mnp->mnt_read : &mnp->mnt_ioctl;
/*
* Return all the attributes. Should be refined
* so that it returns only those asked for.
@@ -814,6 +827,7 @@ mntgetattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
*/
vap->va_size = snap->mnts_textsize ? snap->mnts_textsize :
mntdata->mnt_size;
+ rw_exit(&mnp->mnt_contents);
/*
* Fetch mtime from the vfs mnttab timestamp
*/
@@ -859,6 +873,7 @@ mntgetnode(vnode_t *dp)
mnp = kmem_zalloc(sizeof (mntnode_t), KM_SLEEP);
mnp->mnt_vnode = vn_alloc(KM_SLEEP);
mnp->mnt_mountvp = VTOM(dp)->mnt_mountvp;
+ rw_init(&mnp->mnt_contents, NULL, RW_DEFAULT, NULL);
vp = MTOV(mnp);
vp->v_flag = VNOCACHE|VNOMAP|VNOSWAP|VNOMOUNT;
vn_setops(vp, mntvnodeops);
@@ -877,6 +892,7 @@ mntfreenode(mntnode_t *mnp)
{
vnode_t *vp = MTOV(mnp);
+ rw_destroy(&mnp->mnt_contents);
vn_invalid(vp);
vn_free(vp);
kmem_free(mnp, sizeof (*mnp));
@@ -904,8 +920,13 @@ static int
mntseek(vnode_t *vp, offset_t ooff, offset_t *noffp,
caller_context_t *ct)
{
- if (*noffp == 0)
+ mntnode_t *mnp = VTOM(vp);
+
+ if (*noffp == 0) {
+ rw_enter(&mnp->mnt_contents, RW_WRITER);
VTOM(vp)->mnt_offset = 0;
+ rw_exit(&mnp->mnt_contents);
+ }
return (0);
}
@@ -921,8 +942,10 @@ mntpoll(vnode_t *vp, short ev, int any, short *revp, pollhead_t **phpp,
caller_context_t *ct)
{
mntnode_t *mnp = VTOM(vp);
- mntsnap_t *snap = &mnp->mnt_read;
+ mntsnap_t *snap;
+ rw_enter(&mnp->mnt_contents, RW_READER);
+ snap = &mnp->mnt_read;
if (mnp->mnt_ioctl.mnts_time.tv_sec > snap->mnts_time.tv_sec ||
(mnp->mnt_ioctl.mnts_time.tv_sec == snap->mnts_time.tv_sec &&
mnp->mnt_ioctl.mnts_time.tv_nsec > snap->mnts_time.tv_nsec))
@@ -941,6 +964,8 @@ mntpoll(vnode_t *vp, short ev, int any, short *revp, pollhead_t **phpp,
if (*phpp == (pollhead_t *)NULL)
*revp |= POLLRDBAND;
}
+ rw_exit(&mnp->mnt_contents);
+
if (*revp || *phpp != NULL || any) {
return (0);
}
@@ -960,17 +985,27 @@ mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag,
{
uint_t *up = (uint_t *)arg;
mntnode_t *mnp = VTOM(vp);
- mntsnap_t *snap = &mnp->mnt_ioctl;
+ mntsnap_t *snap;
int error;
error = 0;
+ rw_enter(&mnp->mnt_contents, RW_READER);
+ snap = &mnp->mnt_ioctl;
switch (cmd) {
case MNTIOC_NMNTS: { /* get no. of mounted resources */
if (snap->mnts_count == 0) {
+ if (!rw_tryupgrade(&mnp->mnt_contents)) {
+ rw_exit(&mnp->mnt_contents);
+ rw_enter(&mnp->mnt_contents, RW_WRITER);
+ }
if ((error =
- mntfs_snapshot(mnp, 0, flag & DATAMODEL_MASK)) != 0)
+ mntfs_snapshot(mnp, 0, flag & DATAMODEL_MASK))
+ != 0) {
+ rw_exit(&mnp->mnt_contents);
return (error);
+ }
+ rw_downgrade(&mnp->mnt_contents);
}
if (suword32(up, snap->mnts_count) != 0)
error = EFAULT;
@@ -983,9 +1018,17 @@ mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag,
size_t len;
if (snap->mnts_count == 0) {
+ if (!rw_tryupgrade(&mnp->mnt_contents)) {
+ rw_exit(&mnp->mnt_contents);
+ rw_enter(&mnp->mnt_contents, RW_WRITER);
+ }
if ((error =
- mntfs_snapshot(mnp, 0, flag & DATAMODEL_MASK)) != 0)
+ mntfs_snapshot(mnp, 0, flag & DATAMODEL_MASK))
+ != 0) {
+ rw_exit(&mnp->mnt_contents);
return (error);
+ }
+ rw_downgrade(&mnp->mnt_contents);
}
len = 2 * snap->mnts_count * sizeof (uint_t);
@@ -1090,11 +1133,18 @@ mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag,
size_t idx;
uintptr_t addr;
+ if (!rw_tryupgrade(&mnp->mnt_contents)) {
+ rw_exit(&mnp->mnt_contents);
+ rw_enter(&mnp->mnt_contents, RW_WRITER);
+ }
idx = mnp->mnt_offset;
if (snap->mnts_count == 0 || idx == 0) {
if ((error =
- mntfs_snapshot(mnp, 0, flag & DATAMODEL_MASK)) != 0)
+ mntfs_snapshot(mnp, 0, flag & DATAMODEL_MASK))
+ != 0) {
+ rw_exit(&mnp->mnt_contents);
return (error);
+ }
}
/*
* If the next index is beyond the end of the current mnttab,
@@ -1102,6 +1152,7 @@ mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag,
*/
if (idx >= snap->mnts_count) {
*rvalp = 1;
+ rw_exit(&mnp->mnt_contents);
return (0);
}
@@ -1119,8 +1170,10 @@ mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag,
}
#endif
- if (error != 0)
+ if (error != 0) {
+ rw_exit(&mnp->mnt_contents);
return (error);
+ }
mnp->mnt_offset++;
break;
@@ -1131,6 +1184,7 @@ mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag,
break;
}
+ rw_exit(&mnp->mnt_contents);
return (error);
}
diff --git a/usr/src/uts/common/sys/fs/mntdata.h b/usr/src/uts/common/sys/fs/mntdata.h
index d15c64d1b4..1536b6c712 100644
--- a/usr/src/uts/common/sys/fs/mntdata.h
+++ b/usr/src/uts/common/sys/fs/mntdata.h
@@ -2,9 +2,8 @@
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (the "License"). You may not use this file except in compliance
- * with the License.
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
@@ -20,15 +19,13 @@
* CDDL HEADER END
*/
/*
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_MNTFS_MNTDATA_H
#define _SYS_MNTFS_MNTDATA_H
-#pragma ident "%Z%%M% %I% %E% SMI"
-
#include <sys/vnode.h>
#include <sys/poll.h>
@@ -52,6 +49,7 @@ typedef struct mntnode {
mntsnap_t mnt_read; /* Data for read() */
mntsnap_t mnt_ioctl; /* Data for ioctl() */
uint_t mnt_offset; /* offset within ioctl() snapshot */
+ krwlock_t mnt_contents; /* protects mnt_read, mnt_ioctl, mnt_offset */
} mntnode_t;
struct zone;
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-26 19:44:18 +0000