xnu-6153.141.1.tar.gz

[apple/xnu.git] / bsd / miscfs / nullfs / null_vnops.c

diff --git a/bsd/miscfs/nullfs/null_vnops.c b/bsd/miscfs/nullfs/null_vnops.c
index 389adb7e4b3b34a12a76560c998ab92b5ac8e13f..6afadbfab808bd2253271253f6f39636808e0b98 100644 (file)
--- a/bsd/miscfs/nullfs/null_vnops.c
+++ b/bsd/miscfs/nullfs/null_vnops.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2016 Apple Inc. All rights reserved.
+ * Copyright (c) 2019 Apple Inc. All rights reserved.

  *
  * @APPLE_LICENSE_HEADER_START@
  *
  *
  * @APPLE_LICENSE_HEADER_START@
  *


@@ -179,14 +179,14 @@ nullfs_special_getattr(struct vnop_getattr_args * args)
        VATTR_RETURN(args->a_vap, va_filerev, 0);
        VATTR_RETURN(args->a_vap, va_gen, 0);
        VATTR_RETURN(args->a_vap, va_flags, UF_HIDDEN); /* mark our fake directories as hidden. People
        VATTR_RETURN(args->a_vap, va_filerev, 0);
        VATTR_RETURN(args->a_vap, va_gen, 0);
        VATTR_RETURN(args->a_vap, va_flags, UF_HIDDEN); /* mark our fake directories as hidden. People

-                                                          shouldn't be enocouraged to poke around in them */
+                                                        *  shouldn't be enocouraged to poke around in them */

 
        if (ino == NULL_SECOND_INO) {
                VATTR_RETURN(args->a_vap, va_parentid, NULL_ROOT_INO); /* no parent at the root, so
 
        if (ino == NULL_SECOND_INO) {
                VATTR_RETURN(args->a_vap, va_parentid, NULL_ROOT_INO); /* no parent at the root, so

-                                                                         the only other vnode that
-                                                                         goes through this path is
-                                                                         second and its parent is
-                                                                         1.*/
+                                                                       *  the only other vnode that
+                                                                       *  goes through this path is
+                                                                       *  second and its parent is
+                                                                       *  1.*/

        }
 
        if (VATTR_IS_ACTIVE(args->a_vap, va_mode)) {
        }
 
        if (VATTR_IS_ACTIVE(args->a_vap, va_mode)) {


@@ -298,10 +298,10 @@ nullfs_close(struct vnop_close_args * args)
 }
 
 /* get lvp's parent, if possible, even if it isn't set.
 }
 
 /* get lvp's parent, if possible, even if it isn't set.

-
-   lvp is expected to have an iocount before and after this call.
-
-   if a dvpp is populated the returned vnode has an iocount. */
+ *
+ *  lvp is expected to have an iocount before and after this call.
+ *
+ *  if a dvpp is populated the returned vnode has an iocount. */

 static int
 null_get_lowerparent(vnode_t lvp, vnode_t * dvpp, vfs_context_t ctx)
 {
 static int
 null_get_lowerparent(vnode_t lvp, vnode_t * dvpp, vfs_context_t ctx)
 {


@@ -379,7 +379,6 @@ null_special_lookup(struct vnop_lookup_args * ap)
                                error = vnode_get(vp);
                        }
                }
                                error = vnode_get(vp);
                        }
                }

-

        } else if (dvp == null_mp->nullm_secondvp) {
                /* handle . and .. */
                if (cnp->cn_nameptr[0] == '.') {
        } else if (dvp == null_mp->nullm_secondvp) {
                /* handle . and .. */
                if (cnp->cn_nameptr[0] == '.') {


@@ -397,21 +396,21 @@ null_special_lookup(struct vnop_lookup_args * ap)
                /* nullmp->nullm_lowerrootvp was set at mount time so don't need to lock to
                 * access it */
                /* v_name should be null terminated but cn_nameptr is not necessarily.
                /* nullmp->nullm_lowerrootvp was set at mount time so don't need to lock to
                 * access it */
                /* v_name should be null terminated but cn_nameptr is not necessarily.

-                  cn_namelen is the number of characters before the null in either case */
+                *  cn_namelen is the number of characters before the null in either case */

                error = vnode_getwithvid(null_mp->nullm_lowerrootvp, null_mp->nullm_lowerrootvid);
                if (error) {
                        goto end;
                }
 
                /* We don't want to mess with case insensitivity and unicode, so the plan to
                error = vnode_getwithvid(null_mp->nullm_lowerrootvp, null_mp->nullm_lowerrootvid);
                if (error) {
                        goto end;
                }
 
                /* We don't want to mess with case insensitivity and unicode, so the plan to

-                  check here is
-                   1. try to get the lower root's parent
-                   2. If we get a parent, then perform a lookup on the lower file system
-                  using the parent and the passed in cnp
-                   3. If that worked and we got a vp, then see if the vp is lowerrootvp. If
-                  so we got a match
-                   4. Anything else results in ENOENT.
-                   */
+                *  check here is
+                *   1. try to get the lower root's parent
+                *   2. If we get a parent, then perform a lookup on the lower file system
+                *  using the parent and the passed in cnp
+                *   3. If that worked and we got a vp, then see if the vp is lowerrootvp. If
+                *  so we got a match
+                *   4. Anything else results in ENOENT.
+                */

                error = null_get_lowerparent(null_mp->nullm_lowerrootvp, &ldvp, ap->a_context);
 
                if (error == 0) {
                error = null_get_lowerparent(null_mp->nullm_lowerrootvp, &ldvp, ap->a_context);
 
                if (error == 0) {


@@ -464,7 +463,7 @@ null_lookup(struct vnop_lookup_args * ap)
        mp = vnode_mount(dvp);
        /* rename and delete are not allowed. this is a read only file system */
        if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME || cnp->cn_nameiop == CREATE) {
        mp = vnode_mount(dvp);
        /* rename and delete are not allowed. this is a read only file system */
        if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME || cnp->cn_nameiop == CREATE) {

-               return (EROFS);
+               return EROFS;

        }
        null_mp = MOUNTTONULLMOUNT(mp);
 
        }
        null_mp = MOUNTTONULLMOUNT(mp);
 


@@ -530,7 +529,7 @@ notdot:
                vnode_put(lvp);
        }
 
                vnode_put(lvp);
        }
 

-       return (error);
+       return error;

 }
 
 /*
 }
 
 /*


@@ -541,7 +540,7 @@ null_inactive(__unused struct vnop_inactive_args * ap)
 {
        NULLFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
 
 {
        NULLFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
 

-       return (0);
+       return 0;

 }
 
 static int
 }
 
 static int


@@ -568,9 +567,9 @@ null_reclaim(struct vnop_reclaim_args * ap)
                 * got hashed */
                if (xp->null_flags & NULL_FLAG_HASHED) {
                        /* only call this if we actually made it into the hash list. reclaim gets
                 * got hashed */
                if (xp->null_flags & NULL_FLAG_HASHED) {
                        /* only call this if we actually made it into the hash list. reclaim gets

-                          called also to
-                          clean up a vnode that got created when it didn't need to under race
-                          conditions */
+                        *  called also to
+                        *  clean up a vnode that got created when it didn't need to under race
+                        *  conditions */

                        null_hashrem(xp);
                }
                vnode_getwithref(lowervp);
                        null_hashrem(xp);
                }
                vnode_getwithref(lowervp);


@@ -635,15 +634,15 @@ nullfs_special_readdir(struct vnop_readdir_args * ap)
        ino_t ino                   = 0;
        const char * name           = NULL;
 
        ino_t ino                   = 0;
        const char * name           = NULL;
 

-       if (ap->a_flags & (VNODE_READDIR_EXTENDED | VNODE_READDIR_REQSEEKOFF))
-               return (EINVAL);
+       if (ap->a_flags & (VNODE_READDIR_EXTENDED | VNODE_READDIR_REQSEEKOFF)) {
+               return EINVAL;
+       }

 
        if (offset == 0) {
                /* . case */
                if (vp == null_mp->nullm_rootvp) {
                        ino = NULL_ROOT_INO;
 
        if (offset == 0) {
                /* . case */
                if (vp == null_mp->nullm_rootvp) {
                        ino = NULL_ROOT_INO;

-               } else /* only get here if vp matches nullm_rootvp or nullm_secondvp */
-               {
+               } else { /* only get here if vp matches nullm_rootvp or nullm_secondvp */

                        ino = NULL_SECOND_INO;
                }
                error = store_entry_special(ino, ".", uio);
                        ino = NULL_SECOND_INO;
                }
                error = store_entry_special(ino, ".", uio);


@@ -670,13 +669,12 @@ nullfs_special_readdir(struct vnop_readdir_args * ap)
                if (vp == null_mp->nullm_rootvp) {
                        ino  = NULL_SECOND_INO;
                        name = "d";
                if (vp == null_mp->nullm_rootvp) {
                        ino  = NULL_SECOND_INO;
                        name = "d";

-               } else /* only get here if vp matches nullm_rootvp or nullm_secondvp */
-               {
+               } else { /* only get here if vp matches nullm_rootvp or nullm_secondvp */

                        ino = NULL_THIRD_INO;
                        if (vnode_getwithvid(null_mp->nullm_lowerrootvp, null_mp->nullm_lowerrootvid)) {
                                /* In this case the lower file system has been ripped out from under us,
                        ino = NULL_THIRD_INO;
                        if (vnode_getwithvid(null_mp->nullm_lowerrootvp, null_mp->nullm_lowerrootvid)) {
                                /* In this case the lower file system has been ripped out from under us,

-                                  but we don't want to error out
-                                  Instead we just want d to look empty. */
+                                *  but we don't want to error out
+                                *  Instead we just want d to look empty. */

                                error = 0;
                                goto out;
                        }
                                error = 0;
                                goto out;
                        }


@@ -699,7 +697,7 @@ nullfs_special_readdir(struct vnop_readdir_args * ap)
 out:
        if (error == EMSGSIZE) {
                error = 0; /* return success if we ran out of space, but we wanted to make
 out:
        if (error == EMSGSIZE) {
                error = 0; /* return success if we ran out of space, but we wanted to make

-                             sure that we didn't update offset and items incorrectly */
+                           *  sure that we didn't update offset and items incorrectly */

        }
        uio_setoffset(uio, offset);
        if (ap->a_numdirent) {
        }
        uio_setoffset(uio, offset);
        if (ap->a_numdirent) {


@@ -834,7 +832,7 @@ nullfs_getxattr(struct vnop_getxattr_args * args)
        NULLFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
 
        if (nullfs_checkspecialvp(args->a_vp)) {
        NULLFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
 
        if (nullfs_checkspecialvp(args->a_vp)) {

-               return 0; /* nothing extra needed */
+               return ENOATTR; /* no xattrs on the special vnodes */

        }
 
        vp    = args->a_vp;
        }
 
        vp    = args->a_vp;


@@ -857,7 +855,7 @@ nullfs_listxattr(struct vnop_listxattr_args * args)
        NULLFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
 
        if (nullfs_checkspecialvp(args->a_vp)) {
        NULLFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
 
        if (nullfs_checkspecialvp(args->a_vp)) {

-               return 0; /* nothing extra needed */
+               return 0; /* no xattrs on the special vnodes */

        }
 
        vp    = args->a_vp;
        }
 
        vp    = args->a_vp;


@@ -925,13 +923,12 @@ nullfs_pagein(struct vnop_pagein_args * ap)
                error = VNOP_READ(lvp, auio, ((ap->a_flags & UPL_IOSYNC) ? IO_SYNC : 0), ap->a_context);
 
                bytes_remaining = uio_resid(auio);
                error = VNOP_READ(lvp, auio, ((ap->a_flags & UPL_IOSYNC) ? IO_SYNC : 0), ap->a_context);
 
                bytes_remaining = uio_resid(auio);

-               if (bytes_remaining > 0 && bytes_remaining <= (user_ssize_t)ap->a_size)
-               {
+               if (bytes_remaining > 0 && bytes_remaining <= (user_ssize_t)ap->a_size) {

                        /* zero bytes that weren't read in to the upl */
                        bzero((void*)((uintptr_t)(ioaddr + ap->a_size - bytes_remaining)), (size_t) bytes_remaining);
                }
 
                        /* zero bytes that weren't read in to the upl */
                        bzero((void*)((uintptr_t)(ioaddr + ap->a_size - bytes_remaining)), (size_t) bytes_remaining);
                }
 

-       exit:
+exit:

                kret = ubc_upl_unmap(upl);
                if (KERN_SUCCESS != kret) {
                        panic("nullfs_pagein: ubc_upl_unmap() failed with (%d)", kret);
                kret = ubc_upl_unmap(upl);
                if (KERN_SUCCESS != kret) {
                        panic("nullfs_pagein: ubc_upl_unmap() failed with (%d)", kret);


@@ -941,16 +938,14 @@ nullfs_pagein(struct vnop_pagein_args * ap)
                        uio_free(auio);
                }
 
                        uio_free(auio);
                }
 

-       exit_no_unmap:
+exit_no_unmap:

                if ((ap->a_flags & UPL_NOCOMMIT) == 0) {
                        if (!error && (bytes_remaining >= 0) && (bytes_remaining <= (user_ssize_t)ap->a_size)) {
                                /* only commit what was read in (page aligned)*/
                                bytes_to_commit = ap->a_size - bytes_remaining;
                if ((ap->a_flags & UPL_NOCOMMIT) == 0) {
                        if (!error && (bytes_remaining >= 0) && (bytes_remaining <= (user_ssize_t)ap->a_size)) {
                                /* only commit what was read in (page aligned)*/
                                bytes_to_commit = ap->a_size - bytes_remaining;

-                               if (bytes_to_commit)
-                               {
+                               if (bytes_to_commit) {

                                        /* need to make sure bytes_to_commit and byte_remaining are page aligned before calling ubc_upl_commit_range*/
                                        /* need to make sure bytes_to_commit and byte_remaining are page aligned before calling ubc_upl_commit_range*/

-                                       if (bytes_to_commit & PAGE_MASK)
-                                       {
+                                       if (bytes_to_commit & PAGE_MASK) {

                                                bytes_to_commit = (bytes_to_commit & (~PAGE_MASK)) + (PAGE_MASK + 1);
                                                assert(bytes_to_commit <= (off_t)ap->a_size);
 
                                                bytes_to_commit = (bytes_to_commit & (~PAGE_MASK)) + (PAGE_MASK + 1);
                                                assert(bytes_to_commit <= (off_t)ap->a_size);
 


@@ -958,7 +953,7 @@ nullfs_pagein(struct vnop_pagein_args * ap)
                                        }
                                        ubc_upl_commit_range(upl, ap->a_pl_offset, (upl_size_t)bytes_to_commit, UPL_COMMIT_FREE_ON_EMPTY);
                                }
                                        }
                                        ubc_upl_commit_range(upl, ap->a_pl_offset, (upl_size_t)bytes_to_commit, UPL_COMMIT_FREE_ON_EMPTY);
                                }

-                               
+

                                /* abort anything thats left */
                                if (bytes_remaining) {
                                        ubc_upl_abort_range(upl, ap->a_pl_offset + bytes_to_commit, (upl_size_t)bytes_remaining, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);
                                /* abort anything thats left */
                                if (bytes_remaining) {
                                        ubc_upl_abort_range(upl, ap->a_pl_offset + bytes_to_commit, (upl_size_t)bytes_remaining, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);


@@ -968,7 +963,7 @@ nullfs_pagein(struct vnop_pagein_args * ap)
                        }
                }
                vnode_put(lvp);
                        }
                }
                vnode_put(lvp);

-       } else if((ap->a_flags & UPL_NOCOMMIT) == 0) {
+       } else if ((ap->a_flags & UPL_NOCOMMIT) == 0) {

                ubc_upl_abort_range(ap->a_pl, ap->a_pl_offset, (upl_size_t)ap->a_size, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);
        }
        return error;
                ubc_upl_abort_range(ap->a_pl, ap->a_pl_offset, (upl_size_t)ap->a_size, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);
        }
        return error;


@@ -1012,7 +1007,7 @@ nullfs_read(struct vnop_read_args * ap)
                if (error) {
                        NULLFSDEBUG("VNOP_READ failed: %d\n", error);
                }
                if (error) {
                        NULLFSDEBUG("VNOP_READ failed: %d\n", error);
                }

-       end:
+end:

                vnode_put(lvp);
        }
        return error;
                vnode_put(lvp);
        }
        return error;


@@ -1022,16 +1017,49 @@ nullfs_read(struct vnop_read_args * ap)
  * Global vfs data structures
  */
 
  * Global vfs data structures
  */
 

-static struct vnodeopv_entry_desc nullfs_vnodeop_entries[] = {
-    {&vnop_default_desc, (vop_t)nullfs_default},     {&vnop_getattr_desc, (vop_t)nullfs_getattr},
-    {&vnop_open_desc, (vop_t)nullfs_open},           {&vnop_close_desc, (vop_t)nullfs_close},
-    {&vnop_inactive_desc, (vop_t)null_inactive},     {&vnop_reclaim_desc, (vop_t)null_reclaim},
-    {&vnop_lookup_desc, (vop_t)null_lookup},         {&vnop_readdir_desc, (vop_t)nullfs_readdir},
-    {&vnop_readlink_desc, (vop_t)nullfs_readlink},   {&vnop_pathconf_desc, (vop_t)nullfs_pathconf},
-    {&vnop_fsync_desc, (vop_t)nullfs_fsync},         {&vnop_mmap_desc, (vop_t)nullfs_mmap},
-    {&vnop_mnomap_desc, (vop_t)nullfs_mnomap},       {&vnop_getxattr_desc, (vop_t)nullfs_getxattr},
-    {&vnop_pagein_desc, (vop_t)nullfs_pagein},       {&vnop_read_desc, (vop_t)nullfs_read},
-    {&vnop_listxattr_desc, (vop_t)nullfs_listxattr}, {NULL, NULL},
+static const struct vnodeopv_entry_desc nullfs_vnodeop_entries[] = {
+       {.opve_op = &vnop_default_desc, .opve_impl = (vop_t)nullfs_default}, {.opve_op = &vnop_getattr_desc, .opve_impl = (vop_t)nullfs_getattr},
+       {.opve_op = &vnop_open_desc, .opve_impl = (vop_t)nullfs_open}, {.opve_op = &vnop_close_desc, .opve_impl = (vop_t)nullfs_close},
+       {.opve_op = &vnop_inactive_desc, .opve_impl = (vop_t)null_inactive}, {.opve_op = &vnop_reclaim_desc, .opve_impl = (vop_t)null_reclaim},
+       {.opve_op = &vnop_lookup_desc, .opve_impl = (vop_t)null_lookup}, {.opve_op = &vnop_readdir_desc, .opve_impl = (vop_t)nullfs_readdir},
+       {.opve_op = &vnop_readlink_desc, .opve_impl = (vop_t)nullfs_readlink}, {.opve_op = &vnop_pathconf_desc, .opve_impl = (vop_t)nullfs_pathconf},
+       {.opve_op = &vnop_fsync_desc, .opve_impl = (vop_t)nullfs_fsync}, {.opve_op = &vnop_mmap_desc, .opve_impl = (vop_t)nullfs_mmap},
+       {.opve_op = &vnop_mnomap_desc, .opve_impl = (vop_t)nullfs_mnomap}, {.opve_op = &vnop_getxattr_desc, .opve_impl = (vop_t)nullfs_getxattr},
+       {.opve_op = &vnop_pagein_desc, .opve_impl = (vop_t)nullfs_pagein}, {.opve_op = &vnop_read_desc, .opve_impl = (vop_t)nullfs_read},
+       {.opve_op = &vnop_listxattr_desc, .opve_impl = (vop_t)nullfs_listxattr}, {.opve_op = NULL, .opve_impl = NULL},

 };
 
 };
 

-struct vnodeopv_desc nullfs_vnodeop_opv_desc = {&nullfs_vnodeop_p, nullfs_vnodeop_entries};
+const struct vnodeopv_desc nullfs_vnodeop_opv_desc = {.opv_desc_vector_p = &nullfs_vnodeop_p, .opv_desc_ops = nullfs_vnodeop_entries};
+
+//NULLFS Specific helper function
+
+int
+nullfs_getbackingvnode(vnode_t in_vp, vnode_t* out_vpp)
+{
+       int result = EINVAL;
+
+       if (out_vpp == NULL || in_vp == NULL) {
+               goto end;
+       }
+
+       struct vfsstatfs * sp   = NULL;
+       mount_t mp = vnode_mount(in_vp);
+
+       sp = vfs_statfs(mp);
+       //If this isn't a nullfs vnode or it is but it's a special vnode
+       if (strcmp(sp->f_fstypename, "nullfs") != 0 || nullfs_checkspecialvp(in_vp)) {
+               *out_vpp = NULLVP;
+               result = ENOENT;
+               goto end;
+       }
+
+       vnode_t lvp = NULLVPTOLOWERVP(in_vp);
+       if ((result = vnode_getwithvid(lvp, NULLVPTOLOWERVID(in_vp)))) {
+               goto end;
+       }
+
+       *out_vpp = lvp;
+
+end:
+       return result;
+}