use miscfs include path

[unix-history] / usr / src / sys / miscfs / union / union_vfsops.c

diff --git a/usr/src/sys/miscfs/union/union_vfsops.c b/usr/src/sys/miscfs/union/union_vfsops.c
index c99f096..1fdf2b2 100644 (file)
--- a/usr/src/sys/miscfs/union/union_vfsops.c
+++ b/usr/src/sys/miscfs/union/union_vfsops.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union_vfsops.c      1.5 (Berkeley) %G%
+ *     @(#)union_vfsops.c      8.2 (Berkeley) %G%

  */
 
 /*
  */
 
 /*


@@ -24,7 +24,9 @@
 #include <sys/mount.h>
 #include <sys/namei.h>
 #include <sys/malloc.h>
 #include <sys/mount.h>
 #include <sys/namei.h>
 #include <sys/malloc.h>

-#include "union.h"
+#include <sys/filedesc.h>
+#include <sys/queue.h>
+#include <miscfs/union/union.h>

 
 /*
  * Mount union filesystem
 
 /*
  * Mount union filesystem


@@ -39,9 +41,12 @@ union_mount(mp, path, data, ndp, p)
 {
        int error = 0;
        struct union_args args;
 {
        int error = 0;
        struct union_args args;

-       struct vnode *lowerrootvp;
-       struct vnode *upperrootvp;
+       struct vnode *lowerrootvp = NULLVP;
+       struct vnode *upperrootvp = NULLVP;

        struct union_mount *um;
        struct union_mount *um;

+       struct ucred *cred = 0;
+       char *cp;
+       int len;

        u_int size;
 
 #ifdef UNION_DIAGNOSTIC
        u_int size;
 
 #ifdef UNION_DIAGNOSTIC


@@ -57,14 +62,35 @@ union_mount(mp, path, data, ndp, p)
                 * 1. a way to convert between rdonly and rdwr mounts.
                 * 2. support for nfs exports.
                 */
                 * 1. a way to convert between rdonly and rdwr mounts.
                 * 2. support for nfs exports.
                 */

-               return (EOPNOTSUPP);
+               error = EOPNOTSUPP;
+               goto bad;

        }
 
        }
 

+       /*
+        * Take a copy of the process's credentials.  This isn't
+        * quite right since the euid will always be zero and we
+        * want to get the "real" users credentials.  So fix up
+        * the uid field after taking the copy.
+        */
+       cred = crdup(p->p_ucred);
+       cred->cr_uid = p->p_cred->p_ruid;
+
+       /*
+        * Ensure the *real* user has write permission on the
+        * mounted-on directory.  This allows the mount_union
+        * command to be made setuid root so allowing anyone
+        * to do union mounts onto any directory on which they
+        * have write permission.
+        */
+       error = VOP_ACCESS(mp->mnt_vnodecovered, VWRITE, cred, p);
+       if (error)
+               goto bad;
+

        /*
         * Get argument
         */
        if (error = copyin(data, (caddr_t)&args, sizeof(struct union_args)))
        /*
         * Get argument
         */
        if (error = copyin(data, (caddr_t)&args, sizeof(struct union_args)))

-               return (error);
+               goto bad;

 
        lowerrootvp = mp->mnt_vnodecovered;
        VREF(lowerrootvp);
 
        lowerrootvp = mp->mnt_vnodecovered;
        VREF(lowerrootvp);


@@ -74,17 +100,16 @@ union_mount(mp, path, data, ndp, p)
         */
        NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT,
               UIO_USERSPACE, args.target, p);
         */
        NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT,
               UIO_USERSPACE, args.target, p);

-       if (error = namei(ndp)) {
-               vrele(lowerrootvp);
-               return (error);
-       }
+       if (error = namei(ndp))
+               goto bad;
+

        upperrootvp = ndp->ni_vp;
        vrele(ndp->ni_dvp);
        ndp->ni_dvp = NULL;
 
        if (upperrootvp->v_type != VDIR) {
        upperrootvp = ndp->ni_vp;
        vrele(ndp->ni_dvp);
        ndp->ni_dvp = NULL;
 
        if (upperrootvp->v_type != VDIR) {

-               vrele(upperrootvp);
-               return (EINVAL);
+               error = EINVAL;
+               goto bad;

        }
        
        um = (struct union_mount *) malloc(sizeof(struct union_mount),
        }
        
        um = (struct union_mount *) malloc(sizeof(struct union_mount),


@@ -93,21 +118,52 @@ union_mount(mp, path, data, ndp, p)
        /*
         * Keep a held reference to the target vnodes.
         * They are vrele'd in union_unmount.
        /*
         * Keep a held reference to the target vnodes.
         * They are vrele'd in union_unmount.

+        *
+        * Depending on the _BELOW flag, the filesystems are
+        * viewed in a different order.  In effect, this is the
+        * same as providing a mount under option to the mount syscall.

         */
         */

-       um->um_lowervp = lowerrootvp;
-       um->um_uppervp = upperrootvp;
+
+       switch (args.mntflags & UNMNT_OPMASK) {
+       case UNMNT_ABOVE:
+               um->um_lowervp = lowerrootvp;
+               um->um_uppervp = upperrootvp;
+               break;
+
+       case UNMNT_BELOW:
+               um->um_lowervp = upperrootvp;
+               um->um_uppervp = lowerrootvp;
+               break;
+
+       case UNMNT_REPLACE:
+               vrele(lowerrootvp);
+               lowerrootvp = NULLVP;
+               um->um_uppervp = upperrootvp;
+               um->um_lowervp = lowerrootvp;
+               break;
+
+       default:
+               error = EINVAL;
+               goto bad;
+       }
+
+       um->um_cred = cred;
+       um->um_cmode = UN_DIRMODE &~ p->p_fd->fd_cmask;
+

        /*
        /*

-        * Take a copy of the process's credentials.  This isn't
-        * quite right since the euid will always be zero and we
-        * want to get the "real" users credentials.  So fix up
-        * the uid field after taking the copy.
+        * Depending on what you think the MNT_LOCAL flag might mean,
+        * you may want the && to be || on the conditional below.
+        * At the moment it has been defined that the filesystem is
+        * only local if it is all local, ie the MNT_LOCAL flag implies
+        * that the entire namespace is local.  If you think the MNT_LOCAL
+        * flag implies that some of the files might be stored locally
+        * then you will want to change the conditional.

         */
         */

-       um->um_cred = crdup(p->p_ucred);
-       um->um_cred->cr_uid = p->p_cred->p_ruid;
-
-       if ((lowerrootvp->v_mount->mnt_flag & MNT_LOCAL) &&
-           (upperrootvp->v_mount->mnt_flag & MNT_LOCAL))
+       if (((um->um_lowervp == NULLVP) ||
+            (um->um_lowervp->v_mount->mnt_flag & MNT_LOCAL)) &&
+           (um->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))

                mp->mnt_flag |= MNT_LOCAL;
                mp->mnt_flag |= MNT_LOCAL;

+

        /*
         * Copy in the upper layer's RDONLY flag.  This is for the benefit
         * of lookup() which explicitly checks the flag, rather than asking
        /*
         * Copy in the upper layer's RDONLY flag.  This is for the benefit
         * of lookup() which explicitly checks the flag, rather than asking


@@ -115,21 +171,47 @@ union_mount(mp, path, data, ndp, p)
         * mount of the underlying filesystem to go from rdonly to rdwr
         * will leave the unioned view as read-only.
         */
         * mount of the underlying filesystem to go from rdonly to rdwr
         * will leave the unioned view as read-only.
         */

-       mp->mnt_flag |= (upperrootvp->v_mount->mnt_flag & MNT_RDONLY);
+       mp->mnt_flag |= (um->um_uppervp->v_mount->mnt_flag & MNT_RDONLY);

        mp->mnt_data = (qaddr_t) um;
        getnewfsid(mp, MOUNT_UNION);
 
        (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
        bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
        mp->mnt_data = (qaddr_t) um;
        getnewfsid(mp, MOUNT_UNION);
 
        (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
        bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);

-       bcopy("union:", mp->mnt_stat.f_mntfromname, 6);
-       (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname + 6,
-                       MNAMELEN - 1 - 6, &size);
-       bzero(mp->mnt_stat.f_mntfromname + 6 + size, MNAMELEN - 6 - size);
+
+       switch (args.mntflags & UNMNT_OPMASK) {
+       case UNMNT_ABOVE:
+               cp = "un-above:";
+               break;
+       case UNMNT_BELOW:
+               cp = "un-below:";
+               break;
+       case UNMNT_REPLACE:
+               cp = "replace:";
+               break;
+       }
+       len = strlen(cp);
+       bcopy(cp, mp->mnt_stat.f_mntfromname, len);
+
+       cp = mp->mnt_stat.f_mntfromname + len;
+       len = MNAMELEN - len;
+
+       (void) copyinstr(args.target, cp, len - 1, &size);
+       bzero(cp + size, len - size);
+

 #ifdef UNION_DIAGNOSTIC
 #ifdef UNION_DIAGNOSTIC

-       printf("union_mount: upper %s, lower at %s\n",
+       printf("union_mount: from %s, on %s\n",

                mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
 #endif
        return (0);
                mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
 #endif
        return (0);

+
+bad:
+       if (cred)
+               crfree(cred);
+       if (upperrootvp)
+               vrele(upperrootvp);
+       if (lowerrootvp)
+               vrele(lowerrootvp);
+       return (error);

 }
 
 /*
 }
 
 /*


@@ -190,7 +272,8 @@ union_unmount(mp, mntflags, p)
        /*
         * Discard references to upper and lower target vnodes.
         */
        /*
         * Discard references to upper and lower target vnodes.
         */

-       vrele(um->um_lowervp);
+       if (um->um_lowervp)
+               vrele(um->um_lowervp);

        vrele(um->um_uppervp);
        crfree(um->um_cred);
        /*
        vrele(um->um_uppervp);
        crfree(um->um_cred);
        /*


@@ -206,7 +289,7 @@ union_unmount(mp, mntflags, p)
         */
        free(mp->mnt_data, M_UFSMNT);   /* XXX */
        mp->mnt_data = 0;
         */
        free(mp->mnt_data, M_UFSMNT);   /* XXX */
        mp->mnt_data = 0;

-       return 0;
+       return (0);

 }
 
 int
 }
 
 int


@@ -227,7 +310,9 @@ union_root(mp, vpp)
         * Return locked reference to root.
         */
        VREF(um->um_uppervp);
         * Return locked reference to root.
         */
        VREF(um->um_uppervp);

-       VREF(um->um_lowervp);
+       VOP_LOCK(um->um_uppervp);
+       if (um->um_lowervp)
+               VREF(um->um_lowervp);

        error = union_allocvp(vpp, mp,
                              (struct vnode *) 0,
                              (struct vnode *) 0,
        error = union_allocvp(vpp, mp,
                              (struct vnode *) 0,
                              (struct vnode *) 0,


@@ -237,7 +322,8 @@ union_root(mp, vpp)
 
        if (error) {
                vrele(um->um_uppervp);
 
        if (error) {
                vrele(um->um_uppervp);

-               vrele(um->um_lowervp);
+               if (um->um_lowervp)
+                       vrele(um->um_lowervp);

        } else {
                (*vpp)->v_flag |= VROOT;
        }
        } else {
                (*vpp)->v_flag |= VROOT;
        }


@@ -276,9 +362,11 @@ union_statfs(mp, sbp, p)
 
        bzero(&mstat, sizeof(mstat));
 
 
        bzero(&mstat, sizeof(mstat));
 

-       error = VFS_STATFS(um->um_lowervp->v_mount, &mstat, p);
-       if (error)
-               return (error);
+       if (um->um_lowervp) {
+               error = VFS_STATFS(um->um_lowervp->v_mount, &mstat, p);
+               if (error)
+                       return (error);
+       }

 
        /* now copy across the "interesting" information and fake the rest */
 #if 0
 
        /* now copy across the "interesting" information and fake the rest */
 #if 0