changes for whiteouts and union filesystem

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

diff --git a/usr/src/sys/miscfs/union/union_vnops.c b/usr/src/sys/miscfs/union/union_vnops.c
index 75c237c..fa576fb 100644 (file)
--- a/usr/src/sys/miscfs/union/union_vnops.c
+++ b/usr/src/sys/miscfs/union/union_vnops.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union_vnops.c       8.18 (Berkeley) %G%
+ *     @(#)union_vnops.c       8.19 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -16,6 +16,7 @@
 #include <sys/proc.h>
 #include <sys/file.h>
 #include <sys/time.h>
 #include <sys/proc.h>
 #include <sys/file.h>
 #include <sys/time.h>

+#include <sys/stat.h>

 #include <sys/types.h>
 #include <sys/vnode.h>
 #include <sys/mount.h>
 #include <sys/types.h>
 #include <sys/vnode.h>
 #include <sys/mount.h>


@@ -137,6 +138,8 @@ union_lookup(ap)
        int rdonly = cnp->cn_flags & RDONLY;
        struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount);
        struct ucred *saved_cred;
        int rdonly = cnp->cn_flags & RDONLY;
        struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount);
        struct ucred *saved_cred;

+       int iswhiteout;
+       struct vattr va;

 
 #ifdef notyet
        if (cnp->cn_namelen == 3 &&
 
 #ifdef notyet
        if (cnp->cn_namelen == 3 &&


@@ -160,6 +163,7 @@ union_lookup(ap)
        lowerdvp = dun->un_lowervp;
        uppervp = NULLVP;
        lowervp = NULLVP;
        lowerdvp = dun->un_lowervp;
        uppervp = NULLVP;
        lowervp = NULLVP;

+       iswhiteout = 0;

 
        /*
         * do the lookup in the upper level.
 
        /*
         * do the lookup in the upper level.


@@ -180,6 +184,16 @@ union_lookup(ap)
                                cnp->cn_flags &= ~LOCKPARENT;
                        return (uerror);
                }
                                cnp->cn_flags &= ~LOCKPARENT;
                        return (uerror);
                }

+               if (uerror == ENOENT || uerror == EJUSTRETURN) {
+                       if (cnp->cn_flags & ISWHITEOUT) {
+                               iswhiteout = 1;
+                       } else if (lowerdvp != NULLVP) {
+                               lerror = VOP_GETATTR(upperdvp, &va,
+                                       cnp->cn_cred, cnp->cn_proc);
+                               if (lerror == 0 && (va.va_flags & OPAQUE))
+                                       iswhiteout = 1;
+                       }
+               }

        } else {
                uerror = ENOENT;
        }
        } else {
                uerror = ENOENT;
        }


@@ -191,7 +205,7 @@ union_lookup(ap)
         * back from the upper layer and return the lower vnode
         * instead.
         */
         * back from the upper layer and return the lower vnode
         * instead.
         */

-       if (lowerdvp != NULLVP) {
+       if (lowerdvp != NULLVP && !iswhiteout) {

                int nameiop;
 
                VOP_LOCK(lowerdvp);
                int nameiop;
 
                VOP_LOCK(lowerdvp);


@@ -355,6 +369,23 @@ union_create(ap)
        return (EROFS);
 }
 
        return (EROFS);
 }
 

+int
+union_whiteout(ap)
+       struct vop_whiteout_args /* {
+               struct vnode *a_dvp;
+               struct componentname *a_cnp;
+               int a_flags;
+       } */ *ap;
+{
+       struct union_node *un = VTOUNION(ap->a_dvp);
+
+       if (un->un_uppervp == NULLVP)
+               return (EOPNOTSUPP);
+
+       FIXUP(un);
+       return (VOP_WHITEOUT(un->un_uppervp, ap->a_cnp, ap->a_flags));
+}
+

 int
 union_mknod(ap)
        struct vop_mknod_args /* {
 int
 union_mknod(ap)
        struct vop_mknod_args /* {


@@ -617,21 +648,11 @@ union_setattr(ap)
         */
        if ((un->un_uppervp == NULLVP) &&
            /* assert(un->un_lowervp != NULLVP) */
         */
        if ((un->un_uppervp == NULLVP) &&
            /* assert(un->un_lowervp != NULLVP) */

-           (un->un_lowervp->v_type == VREG) &&
-           (ap->a_vap->va_size == 0)) {
-               struct vnode *vp;
-
-               error = union_vn_create(&vp, un, ap->a_p);
+           (un->un_lowervp->v_type == VREG)) {
+               error = union_copyup(un, (ap->a_vap->va_size != 0),
+                                               ap->a_cred, ap->a_p);

                if (error)
                        return (error);
                if (error)
                        return (error);

-
-               /* at this point, uppervp is locked */
-               union_newupper(un, vp);
-
-               VOP_UNLOCK(vp);
-               union_vn_close(un->un_uppervp, FWRITE, ap->a_cred, ap->a_p);
-               VOP_LOCK(vp);
-               un->un_flags |= UN_ULOCK;

        }
 
        /*
        }
 
        /*


@@ -704,32 +725,25 @@ union_write(ap)
        } */ *ap;
 {
        int error;
        } */ *ap;
 {
        int error;

-       struct vnode *vp = OTHERVP(ap->a_vp);
-       int dolock = (vp == LOWERVP(ap->a_vp));
+       struct vnode *vp;
+       struct union_node *un = VTOUNION(ap->a_vp);

 
 

-       if (dolock)
-               VOP_LOCK(vp);
-       else
-               FIXUP(VTOUNION(ap->a_vp));
+       vp = UPPERVP(ap->a_vp);
+       if (vp == NULLVP)
+               panic("union: missing upper layer in write");
+
+       FIXUP(un);

        error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
        error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);

-       if (dolock)
-               VOP_UNLOCK(vp);

 
        /*
         * the size of the underlying object may be changed by the
         * write.
         */
        if (error == 0) {
 
        /*
         * the size of the underlying object may be changed by the
         * write.
         */
        if (error == 0) {

-               struct union_node *un = VTOUNION(ap->a_vp);

                off_t cur = ap->a_uio->uio_offset;
 
                off_t cur = ap->a_uio->uio_offset;
 

-               if (vp == un->un_uppervp) {
-                       if (cur > un->un_uppersz)
-                               union_newsize(ap->a_vp, cur, VNOVAL);
-               } else {
-                       if (cur > un->un_lowersz)
-                               union_newsize(ap->a_vp, VNOVAL, cur);
-               }
+               if (cur > un->un_uppersz)
+                       union_newsize(ap->a_vp, cur, VNOVAL);

        }
 
        return (error);
        }
 
        return (error);


@@ -833,7 +847,10 @@ union_remove(ap)
        struct union_node *dun = VTOUNION(ap->a_dvp);
        struct union_node *un = VTOUNION(ap->a_vp);
 
        struct union_node *dun = VTOUNION(ap->a_dvp);
        struct union_node *un = VTOUNION(ap->a_vp);
 

-       if (dun->un_uppervp != NULLVP && un->un_uppervp != NULLVP) {
+       if (dun->un_uppervp == NULLVP)
+               panic("union remove: null upper vnode");
+
+       if (un->un_uppervp != NULLVP) {

                struct vnode *dvp = dun->un_uppervp;
                struct vnode *vp = un->un_uppervp;
 
                struct vnode *dvp = dun->un_uppervp;
                struct vnode *vp = un->un_uppervp;
 


@@ -846,20 +863,18 @@ union_remove(ap)
                un->un_flags |= UN_KLOCK;
                vput(ap->a_vp);
 
                un->un_flags |= UN_KLOCK;
                vput(ap->a_vp);
 

+               if (un->un_lowervp != NULLVP)
+                       ap->a_cnp->cn_flags |= DOWHITEOUT;

                error = VOP_REMOVE(dvp, vp, ap->a_cnp);
                if (!error)
                        union_removed_upper(un);
                error = VOP_REMOVE(dvp, vp, ap->a_cnp);
                if (!error)
                        union_removed_upper(un);

-
-               /*
-                * XXX: should create a whiteout here
-                */

        } else {
        } else {

-               /*
-                * XXX: should create a whiteout here
-                */
+               FIXUP(dun);
+               error = union_mkwhiteout(
+                       MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount),
+                       dun->un_uppervp, ap->a_cnp, un->un_path);

                vput(ap->a_dvp);
                vput(ap->a_vp);
                vput(ap->a_dvp);
                vput(ap->a_vp);

-               error = EROFS;

        }
 
        return (error);
        }
 
        return (error);


@@ -939,7 +954,13 @@ union_rename(ap)
        if (fdvp->v_op == union_vnodeop_p) {    /* always true */
                struct union_node *un = VTOUNION(fdvp);
                if (un->un_uppervp == NULLVP) {
        if (fdvp->v_op == union_vnodeop_p) {    /* always true */
                struct union_node *un = VTOUNION(fdvp);
                if (un->un_uppervp == NULLVP) {

-                       error = EROFS;
+                       /*
+                        * this should never happen in normal
+                        * operation but might if there was
+                        * a problem creating the top-level shadow
+                        * directory.
+                        */
+                       error = EXDEV;

                        goto bad;
                }
 
                        goto bad;
                }
 


@@ -951,10 +972,14 @@ union_rename(ap)
        if (fvp->v_op == union_vnodeop_p) {     /* always true */
                struct union_node *un = VTOUNION(fvp);
                if (un->un_uppervp == NULLVP) {
        if (fvp->v_op == union_vnodeop_p) {     /* always true */
                struct union_node *un = VTOUNION(fvp);
                if (un->un_uppervp == NULLVP) {

-                       error = EROFS;
+                       /* XXX: should do a copyup */
+                       error = EXDEV;

                        goto bad;
                }
 
                        goto bad;
                }
 

+               if (un->un_lowervp != NULLVP)
+                       ap->a_fcnp->cn_flags |= DOWHITEOUT;
+

                fvp = un->un_uppervp;
                VREF(fvp);
                vrele(ap->a_fvp);
                fvp = un->un_uppervp;
                VREF(fvp);
                vrele(ap->a_fvp);


@@ -969,7 +994,7 @@ union_rename(ap)
                         * a problem creating the top-level shadow
                         * directory.
                         */
                         * a problem creating the top-level shadow
                         * directory.
                         */

-                       error = EROFS;
+                       error = EXDEV;

                        goto bad;
                }
 
                        goto bad;
                }
 


@@ -1055,7 +1080,10 @@ union_rmdir(ap)
        struct union_node *dun = VTOUNION(ap->a_dvp);
        struct union_node *un = VTOUNION(ap->a_vp);
 
        struct union_node *dun = VTOUNION(ap->a_dvp);
        struct union_node *un = VTOUNION(ap->a_vp);
 

-       if (dun->un_uppervp != NULLVP && un->un_uppervp != NULLVP) {
+       if (dun->un_uppervp == NULLVP)
+               panic("union rmdir: null upper vnode");
+
+       if (un->un_uppervp != NULLVP) {

                struct vnode *dvp = dun->un_uppervp;
                struct vnode *vp = un->un_uppervp;
 
                struct vnode *dvp = dun->un_uppervp;
                struct vnode *vp = un->un_uppervp;
 


@@ -1068,20 +1096,18 @@ union_rmdir(ap)
                un->un_flags |= UN_KLOCK;
                vput(ap->a_vp);
 
                un->un_flags |= UN_KLOCK;
                vput(ap->a_vp);
 

+               if (un->un_lowervp != NULLVP)
+                       ap->a_cnp->cn_flags |= DOWHITEOUT;

                error = VOP_RMDIR(dvp, vp, ap->a_cnp);
                if (!error)
                        union_removed_upper(un);
                error = VOP_RMDIR(dvp, vp, ap->a_cnp);
                if (!error)
                        union_removed_upper(un);

-
-               /*
-                * XXX: should create a whiteout here
-                */

        } else {
        } else {

-               /*
-                * XXX: should create a whiteout here
-                */
+               FIXUP(dun);
+               error = union_mkwhiteout(
+                       MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount),
+                       dun->un_uppervp, ap->a_cnp, un->un_path);

                vput(ap->a_dvp);
                vput(ap->a_vp);
                vput(ap->a_dvp);
                vput(ap->a_vp);

-               error = EROFS;

        }
 
        return (error);
        }
 
        return (error);


@@ -1453,6 +1479,7 @@ struct vnodeopv_entry_desc union_vnodeop_entries[] = {
        { &vop_default_desc, vn_default_error },
        { &vop_lookup_desc, union_lookup },             /* lookup */
        { &vop_create_desc, union_create },             /* create */
        { &vop_default_desc, vn_default_error },
        { &vop_lookup_desc, union_lookup },             /* lookup */
        { &vop_create_desc, union_create },             /* create */

+       { &vop_whiteout_desc, union_whiteout },         /* whiteout */

        { &vop_mknod_desc, union_mknod },               /* mknod */
        { &vop_open_desc, union_open },                 /* open */
        { &vop_close_desc, union_close },               /* close */
        { &vop_mknod_desc, union_mknod },               /* mknod */
        { &vop_open_desc, union_open },                 /* open */
        { &vop_close_desc, union_close },               /* close */