]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/hfs/hfs_vfsutils.c
xnu-1699.32.7.tar.gz
[apple/xnu.git] / bsd / hfs / hfs_vfsutils.c
index eb721483c93907c9b45ee493f45a33739f402b78..1032324317b75165d25011e572e18ecc282272ef 100644 (file)
@@ -46,6 +46,7 @@
 #include <sys/utfconv.h>
 #include <sys/kauth.h>
 #include <sys/fcntl.h>
+#include <sys/fsctl.h>
 #include <sys/vnode_internal.h>
 #include <kern/clock.h>
 
@@ -68,6 +69,8 @@ static int  hfs_late_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *v
 
 static u_int32_t hfs_hotfile_freeblocks(struct hfsmount *);
 
+#define HFS_MOUNT_DEBUG 1
+
 
 //*******************************************************************************
 // Note: Finder information in the HFS/HFS+ metadata are considered opaque and
@@ -87,7 +90,6 @@ unsigned char hfs_attrname[] = "Attribute B-tree";
 unsigned char hfs_startupname[] = "Startup File";
 
 
-__private_extern__
 OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
                __unused struct proc *p)
 {
@@ -97,6 +99,7 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
        struct cat_desc cndesc;
        struct cat_attr cnattr;
        struct cat_fork fork;
+       int newvnode_flags = 0;
 
        /* Block size must be a multiple of 512 */
        if (SWAP_BE32(mdb->drAlBlkSiz) == 0 ||
@@ -115,7 +118,7 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
         *
         */
        vcb->vcbSigWord         = SWAP_BE16 (mdb->drSigWord);
-       vcb->vcbCrDate          = to_bsd_time(LocalToUTC(SWAP_BE32(mdb->drCrDate)));
+       vcb->hfs_itime          = to_bsd_time(LocalToUTC(SWAP_BE32(mdb->drCrDate)));
        vcb->localCreateDate    = SWAP_BE32 (mdb->drCrDate);
        vcb->vcbLsMod           = to_bsd_time(LocalToUTC(SWAP_BE32(mdb->drLsMod)));
        vcb->vcbAtrb            = SWAP_BE16 (mdb->drAtrb);
@@ -144,8 +147,13 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
         * When an HFS name cannot be encoded with the current
         * volume encoding we use MacRoman as a fallback.
         */
-       if (error || (utf8chars == 0))
-               (void) mac_roman_to_utf8(mdb->drVN, NAME_MAX, &utf8chars, vcb->vcbVN);
+       if (error || (utf8chars == 0)) {
+               error = mac_roman_to_utf8(mdb->drVN, NAME_MAX, &utf8chars, vcb->vcbVN);
+               /* If we fail to encode to UTF8 from Mac Roman, the name is bad.  Deny the mount */
+               if (error) {
+                       goto MtVolErr;
+               }
+       }
 
        hfsmp->hfs_logBlockSize = BestBlockSizeFit(vcb->blockSize, MAXBSIZE, hfsmp->hfs_logical_block_size);
        vcb->vcbVBMIOSize = kHFSBlockSize;
@@ -180,11 +188,19 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
        cnattr.ca_blocks = fork.cf_blocks;
 
        error = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &fork,
-                               &hfsmp->hfs_extents_vp);
-       if (error) goto MtVolErr;
+                               &hfsmp->hfs_extents_vp, &newvnode_flags);
+       if (error) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfs (std): error creating Ext Vnode (%d) \n", error);
+               }
+               goto MtVolErr;
+       }
        error = MacToVFSError(BTOpenPath(VTOF(hfsmp->hfs_extents_vp),
                                         (KeyCompareProcPtr)CompareExtentKeys));
        if (error) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfs (std): error opening Ext Vnode (%d) \n", error);
+               }
                hfs_unlock(VTOC(hfsmp->hfs_extents_vp));
                goto MtVolErr;
        }
@@ -209,14 +225,20 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
        cnattr.ca_blocks = fork.cf_blocks;
 
        error = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &fork,
-                               &hfsmp->hfs_catalog_vp);
+                               &hfsmp->hfs_catalog_vp, &newvnode_flags);
        if (error) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfs (std): error creating catalog Vnode (%d) \n", error);
+               }
                hfs_unlock(VTOC(hfsmp->hfs_extents_vp));
                goto MtVolErr;
        }
        error = MacToVFSError(BTOpenPath(VTOF(hfsmp->hfs_catalog_vp),
                                         (KeyCompareProcPtr)CompareCatalogKeys));
        if (error) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfs (std): error opening catalog Vnode (%d) \n", error);
+               }
                hfs_unlock(VTOC(hfsmp->hfs_catalog_vp));
                hfs_unlock(VTOC(hfsmp->hfs_extents_vp));
                goto MtVolErr;
@@ -233,8 +255,11 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
        cnattr.ca_blocks = 0;
 
        error = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &fork,
-                                &hfsmp->hfs_allocation_vp);
+                                &hfsmp->hfs_allocation_vp, &newvnode_flags);
        if (error) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfs (std): error creating bitmap Vnode (%d) \n", error);
+               }
                hfs_unlock(VTOC(hfsmp->hfs_catalog_vp));
                hfs_unlock(VTOC(hfsmp->hfs_extents_vp));
                goto MtVolErr;
@@ -244,34 +269,36 @@ OSErr hfs_MountHFSVolume(struct hfsmount *hfsmp, HFSMasterDirectoryBlock *mdb,
        /* mark the volume dirty (clear clean unmount bit) */
        vcb->vcbAtrb &= ~kHFSVolumeUnmountedMask;
 
-    if (error == noErr)
-      {
+    if (error == noErr) {
                error = cat_idlookup(hfsmp, kHFSRootFolderID, 0, NULL, NULL, NULL);
-      }
-
-    if ( error == noErr )
-      {
-        if ( !(vcb->vcbAtrb & kHFSVolumeHardwareLockMask) )            //      if the disk is not write protected
-          {
-            MarkVCBDirty( vcb );                                                               //      mark VCB dirty so it will be written
-          }
-      }
-
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfs (std): error looking up root folder (%d) \n", error);
+               }
+       }
+       
+    if (error == noErr) {
+               /* If the disk isn't write protected.. */
+        if ( !(vcb->vcbAtrb & kHFSVolumeHardwareLockMask)) {
+            MarkVCBDirty (vcb); //     mark VCB dirty so it will be written
+               }
+       }
+       
        /*
         * all done with system files so we can unlock now...
         */
        hfs_unlock(VTOC(hfsmp->hfs_allocation_vp));
        hfs_unlock(VTOC(hfsmp->hfs_catalog_vp));
        hfs_unlock(VTOC(hfsmp->hfs_extents_vp));
-
-    goto       CmdDone;
+       
+       if (error == noErr) {
+               /* If successful, then we can just return once we've unlocked the cnodes */
+               return error;
+       }
 
     //--       Release any resources allocated so far before exiting with an error:
 MtVolErr:
-       ReleaseMetaFileVNode(hfsmp->hfs_catalog_vp);
-       ReleaseMetaFileVNode(hfsmp->hfs_extents_vp);
+       hfsUnmount(hfsmp, NULL);
 
-CmdDone:
     return (error);
 }
 
@@ -281,7 +308,6 @@ CmdDone:
 //
 //*******************************************************************************
 
-__private_extern__
 OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
        off_t embeddedOffset, u_int64_t disksize, __unused struct proc *p, void *args, kauth_cred_t cred)
 {
@@ -294,8 +320,12 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
        struct BTreeInfoRec btinfo;
        u_int16_t  signature;
        u_int16_t  hfs_version;
+       int newvnode_flags = 0;
        int  i;
        OSErr retval;
+       char converted_volname[256];
+       size_t volname_length = 0;
+       size_t conv_volname_length = 0;
 
        signature = SWAP_BE16(vhp->signature);
        hfs_version = SWAP_BE16(vhp->version);
@@ -317,23 +347,38 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                /* Removed printf for invalid HFS+ signature because it gives
                 * false error for UFS root volume 
                 */
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: unknown Volume Signature\n");
+               }
                return (EINVAL);
        }
 
        /* Block size must be at least 512 and a power of 2 */
        blockSize = SWAP_BE32(vhp->blockSize);
-       if (blockSize < 512 || !powerof2(blockSize))
+       if (blockSize < 512 || !powerof2(blockSize)) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: invalid blocksize (%d) \n", blockSize);
+               }
                return (EINVAL);
+       }
    
        /* don't mount a writable volume if its dirty, it must be cleaned by fsck_hfs */
        if ((hfsmp->hfs_flags & HFS_READ_ONLY) == 0 && hfsmp->jnl == NULL &&
-           (SWAP_BE32(vhp->attributes) & kHFSVolumeUnmountedMask) == 0)
+           (SWAP_BE32(vhp->attributes) & kHFSVolumeUnmountedMask) == 0) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: cannot mount dirty non-journaled volumes\n");
+               }
                return (EINVAL);
+       }
 
        /* Make sure we can live with the physical block size. */
        if ((disksize & (hfsmp->hfs_logical_block_size - 1)) ||
            (embeddedOffset & (hfsmp->hfs_logical_block_size - 1)) ||
            (blockSize < hfsmp->hfs_logical_block_size)) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: invalid physical blocksize (%d), hfs_logical_blocksize (%d) \n", 
+                                       blockSize, hfsmp->hfs_logical_block_size);
+               }
                return (ENXIO);
        }
 
@@ -438,9 +483,12 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                SWAP_BE32 (vhp->extentsFile.extents[i].blockCount);
        }
        retval = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &cfork,
-                                &hfsmp->hfs_extents_vp);
+                                &hfsmp->hfs_extents_vp, &newvnode_flags);
        if (retval)
        {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: hfs_getnewvnode returned (%d) getting extentoverflow BT\n", retval);
+               }
                goto ErrorExit;
        }
        hfsmp->hfs_extents_cp = VTOC(hfsmp->hfs_extents_vp);
@@ -450,6 +498,9 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                          (KeyCompareProcPtr) CompareExtentKeysPlus));
        if (retval)
        {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: BTOpenPath returned (%d) getting extentoverflow BT\n", retval);
+               }
                goto ErrorExit;
        }
        /*
@@ -471,8 +522,11 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                SWAP_BE32 (vhp->catalogFile.extents[i].blockCount);
        }
        retval = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &cfork,
-                                &hfsmp->hfs_catalog_vp);
+                                &hfsmp->hfs_catalog_vp, &newvnode_flags);
        if (retval) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: hfs_getnewvnode returned (%d) getting catalog BT\n", retval);
+               }
                goto ErrorExit;
        }
        hfsmp->hfs_catalog_cp = VTOC(hfsmp->hfs_catalog_vp);
@@ -481,6 +535,9 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
        retval = MacToVFSError(BTOpenPath(VTOF(hfsmp->hfs_catalog_vp),
                                          (KeyCompareProcPtr) CompareExtendedCatalogKeys));
        if (retval) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: BTOpenPath returned (%d) getting catalog BT\n", retval);
+               }
                goto ErrorExit;
        }
        if ((hfsmp->hfs_flags & HFS_X) &&
@@ -512,8 +569,11 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                SWAP_BE32 (vhp->allocationFile.extents[i].blockCount);
        }
        retval = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &cfork,
-                                &hfsmp->hfs_allocation_vp);
+                                &hfsmp->hfs_allocation_vp, &newvnode_flags);
        if (retval) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: hfs_getnewvnode returned (%d) getting bitmap\n", retval);
+               }
                goto ErrorExit;
        }
        hfsmp->hfs_allocation_cp = VTOC(hfsmp->hfs_allocation_vp);
@@ -539,8 +599,11 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                        SWAP_BE32 (vhp->attributesFile.extents[i].blockCount);
                }
                retval = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &cfork,
-                                        &hfsmp->hfs_attribute_vp);
+                                        &hfsmp->hfs_attribute_vp, &newvnode_flags);
                if (retval) {
+                       if (HFS_MOUNT_DEBUG) {
+                               printf("hfs_mounthfsplus: hfs_getnewvnode returned (%d) getting EA BT\n", retval);
+                       }
                        goto ErrorExit;
                }
                hfsmp->hfs_attribute_cp = VTOC(hfsmp->hfs_attribute_vp);
@@ -548,6 +611,22 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                retval = MacToVFSError(BTOpenPath(VTOF(hfsmp->hfs_attribute_vp),
                                                  (KeyCompareProcPtr) hfs_attrkeycompare));
                if (retval) {
+                       if (HFS_MOUNT_DEBUG) {
+                               printf("hfs_mounthfsplus: BTOpenPath returned (%d) getting EA BT\n", retval);
+                       }
+                       goto ErrorExit;
+               }
+
+               /* Initialize vnode for virtual attribute data file that spans the 
+                * entire file system space for performing I/O to attribute btree
+                * We hold iocount on the attrdata vnode for the entire duration 
+                * of mount (similar to btree vnodes)
+                */
+               retval = init_attrdata_vnode(hfsmp);
+               if (retval) {
+                       if (HFS_MOUNT_DEBUG) {
+                               printf("hfs_mounthfsplus: init_attrdata_vnode returned (%d) for virtual EA file\n", retval);
+                       }
                        goto ErrorExit;
                }
        }
@@ -572,8 +651,11 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                        SWAP_BE32 (vhp->startupFile.extents[i].blockCount);
                }
                retval = hfs_getnewvnode(hfsmp, NULL, NULL, &cndesc, 0, &cnattr, &cfork,
-                                        &hfsmp->hfs_startup_vp);
+                                        &hfsmp->hfs_startup_vp, &newvnode_flags);
                if (retval) {
+                       if (HFS_MOUNT_DEBUG) {
+                               printf("hfs_mounthfsplus: hfs_getnewvnode returned (%d) getting startup file\n", retval);
+                       }
                        goto ErrorExit;
                }
                hfsmp->hfs_startup_cp = VTOC(hfsmp->hfs_startup_vp);
@@ -583,13 +665,29 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
        /* Pick up volume name and create date */
        retval = cat_idlookup(hfsmp, kHFSRootFolderID, 0, &cndesc, &cnattr, NULL);
        if (retval) {
+               if (HFS_MOUNT_DEBUG) {
+                       printf("hfs_mounthfsplus: cat_idlookup returned (%d) getting rootfolder \n", retval);
+               }
                goto ErrorExit;
        }
-       vcb->vcbCrDate = cnattr.ca_itime;
+       vcb->hfs_itime = cnattr.ca_itime;
        vcb->volumeNameEncodingHint = cndesc.cd_encoding;
        bcopy(cndesc.cd_nameptr, vcb->vcbVN, min(255, cndesc.cd_namelen));
+       volname_length = strlen ((const char*)vcb->vcbVN);
        cat_releasedesc(&cndesc);
+       
+#define DKIOCCSSETLVNAME _IOW('d', 198, char[1024])
+
 
+       /* Send the volume name down to CoreStorage if necessary */     
+       retval = utf8_normalizestr(vcb->vcbVN, volname_length, (u_int8_t*)converted_volname, &conv_volname_length, 256, UTF_PRECOMPOSED);
+       if (retval == 0) {
+               (void) VNOP_IOCTL (hfsmp->hfs_devvp, DKIOCCSSETLVNAME, converted_volname, 0, vfs_context_current());
+       }       
+       
+       /* reset retval == 0. we don't care about errors in volname conversion */
+       retval = 0;
+       
        /* mark the volume dirty (clear clean unmount bit) */
        vcb->vcbAtrb &= ~kHFSVolumeUnmountedMask;
        if (hfsmp->jnl && (hfsmp->hfs_flags & HFS_READ_ONLY) == 0) {
@@ -617,6 +715,9 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                // EROFS is a special error code that means the volume has an external
                                // journal which we couldn't find.  in that case we do not want to
                                // rewrite the volume header - we'll just refuse to mount the volume.
+                               if (HFS_MOUNT_DEBUG) {
+                                       printf("hfs_mounthfsplus: hfs_late_journal_init returned (%d), maybe an external jnl?\n", retval);
+                               }
                                retval = EINVAL;
                                goto ErrorExit;
                        }
@@ -656,7 +757,10 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                        bp = NULL;
                            }
                        }
-
+                       
+                       if (HFS_MOUNT_DEBUG) {
+                               printf("hfs_mounthfsplus: hfs_late_journal_init returned (%d)\n", retval);
+                       }
                        retval = EINVAL;
                        goto ErrorExit;
                } else if (hfsmp->jnl) {
@@ -690,7 +794,7 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
        /*
         * Establish a metadata allocation zone.
         */
-       hfs_metadatazone_init(hfsmp);
+       hfs_metadatazone_init(hfsmp, false);
 
        /*
         * Make any metadata zone adjustments.
@@ -719,8 +823,13 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
        if ((hfsmp->hfs_flags & HFS_READ_ONLY) == 0)
        {
                retval = hfs_erase_unused_nodes(hfsmp);
-               if (retval)
+               if (retval) {
+                       if (HFS_MOUNT_DEBUG) {
+                               printf("hfs_mounthfsplus: hfs_erase_unused_nodes returned (%d) for %s \n", retval, hfsmp->vcbVN);
+                       }
+
                        goto ErrorExit;
+               }
        }
        
        if ( !(vcb->vcbAtrb & kHFSVolumeHardwareLockMask) )     // if the disk is not write protected
@@ -732,30 +841,33 @@ OSErr hfs_MountHFSPlusVolume(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
         * Allow hot file clustering if conditions allow.
         */
        if ((hfsmp->hfs_flags & HFS_METADATA_ZONE)  &&
-           ((hfsmp->hfs_flags & HFS_READ_ONLY) == 0) &&
-           ((hfsmp->hfs_mp->mnt_kern_flag & MNTK_SSD) == 0)) {
+           ((hfsmp->hfs_flags & (HFS_READ_ONLY | HFS_SSD)) == 0)) {
                (void) hfs_recording_init(hfsmp);
        }
 
        /* Force ACLs on HFS+ file systems. */
        vfs_setextendedsecurity(HFSTOVFS(hfsmp));
 
-       /* Check if volume supports writing of extent-based extended attributes */
-       hfs_check_volxattr(hfsmp, HFS_SET_XATTREXTENTS_STATE);
+       /* Enable extent-based extended attributes by default */
+       hfsmp->hfs_flags |= HFS_XATTR_EXTENTS;
+
+       /* See if this volume should have per-file content protection enabled */
+       if (vcb->vcbAtrb & kHFSContentProtectionMask) {
+               vfs_setflags (hfsmp->hfs_mp, MNT_CPROTECT);
+       }
 
        return (0);
 
 ErrorExit:
        /*
-        * A fatal error occurred and the volume cannot be mounted
-        * release any resources that we aquired...
+        * A fatal error occurred and the volume cannot be mounted, so 
+        * release any resources that we acquired...
         */
-       if (hfsmp->hfs_attribute_vp)
-               ReleaseMetaFileVNode(hfsmp->hfs_attribute_vp);
-       ReleaseMetaFileVNode(hfsmp->hfs_allocation_vp);
-       ReleaseMetaFileVNode(hfsmp->hfs_catalog_vp);
-       ReleaseMetaFileVNode(hfsmp->hfs_extents_vp);
-
+       hfsUnmount(hfsmp, NULL);
+               
+       if (HFS_MOUNT_DEBUG) {
+               printf("hfs_mounthfsplus: encountered errorr (%d)\n", retval);
+       }
        return (retval);
 }
 
@@ -790,44 +902,47 @@ static void ReleaseMetaFileVNode(struct vnode *vp)
 *
 *************************************************************/
 
-__private_extern__
 int
 hfsUnmount( register struct hfsmount *hfsmp, __unused struct proc *p)
 {
-       /* Get rid of our attribute data vnode (if any). */
+       /* Get rid of our attribute data vnode (if any).  This is done 
+        * after the vflush() during mount, so we don't need to worry 
+        * about any locks.
+        */
        if (hfsmp->hfs_attrdata_vp) {
-               vnode_t advp = hfsmp->hfs_attrdata_vp;
-       
-               if (vnode_get(advp) == 0) {
-                       vnode_rele_ext(advp, O_EVTONLY, 0);
-                       vnode_put(advp);
-               }
+               ReleaseMetaFileVNode(hfsmp->hfs_attrdata_vp);
                hfsmp->hfs_attrdata_vp = NULLVP;
        }
 
-       if (hfsmp->hfs_startup_vp)
+       if (hfsmp->hfs_startup_vp) {
                ReleaseMetaFileVNode(hfsmp->hfs_startup_vp);
-
-       if (hfsmp->hfs_allocation_vp)
-               ReleaseMetaFileVNode(hfsmp->hfs_allocation_vp);
-
-       if (hfsmp->hfs_attribute_vp)
+               hfsmp->hfs_startup_cp = NULL;
+               hfsmp->hfs_startup_vp = NULL;
+       }
+       
+       if (hfsmp->hfs_attribute_vp) {
                ReleaseMetaFileVNode(hfsmp->hfs_attribute_vp);
+               hfsmp->hfs_attribute_cp = NULL;
+               hfsmp->hfs_attribute_vp = NULL;
+       }
 
-       ReleaseMetaFileVNode(hfsmp->hfs_catalog_vp);
-       ReleaseMetaFileVNode(hfsmp->hfs_extents_vp);
+       if (hfsmp->hfs_catalog_vp) {
+               ReleaseMetaFileVNode(hfsmp->hfs_catalog_vp);
+               hfsmp->hfs_catalog_cp = NULL;
+               hfsmp->hfs_catalog_vp = NULL;
+       }
 
-       /*
-        * Setting these pointers to NULL so that any references
-        * past this point will fail, and tell us the point of failure.
-        * Also, facilitates a check in hfs_update for a null catalog
-        * vp
-        */
-       hfsmp->hfs_allocation_vp = NULL;
-       hfsmp->hfs_attribute_vp = NULL;
-       hfsmp->hfs_catalog_vp = NULL;
-       hfsmp->hfs_extents_vp = NULL;
-       hfsmp->hfs_startup_vp = NULL;
+       if (hfsmp->hfs_extents_vp) {
+               ReleaseMetaFileVNode(hfsmp->hfs_extents_vp);
+               hfsmp->hfs_extents_cp = NULL;
+               hfsmp->hfs_extents_vp = NULL;
+       }
+
+       if (hfsmp->hfs_allocation_vp) {
+               ReleaseMetaFileVNode(hfsmp->hfs_allocation_vp);
+               hfsmp->hfs_allocation_cp = NULL;
+               hfsmp->hfs_allocation_vp = NULL;
+       }
 
        return (0);
 }
@@ -873,11 +988,56 @@ overflow_extents(struct filefork *fp)
        return (fp->ff_blocks > blocks);
 }
 
+/*
+ * Lock the HFS global journal lock 
+ */
+int 
+hfs_lock_global (struct hfsmount *hfsmp, enum hfslocktype locktype) {
+
+       void *thread = current_thread();
+
+       if (hfsmp->hfs_global_lockowner == thread) {
+               panic ("hfs_lock_global: locking against myself!");
+       }
+
+    /* HFS_SHARED_LOCK */
+       if (locktype == HFS_SHARED_LOCK) {
+               lck_rw_lock_shared (&hfsmp->hfs_global_lock);
+               hfsmp->hfs_global_lockowner = HFS_SHARED_OWNER;
+       }
+    /* HFS_EXCLUSIVE_LOCK */
+       else {
+               lck_rw_lock_exclusive (&hfsmp->hfs_global_lock);
+               hfsmp->hfs_global_lockowner = thread;
+       }
+
+       return 0;
+}
+
+
+/*
+ * Unlock the HFS global journal lock
+ */
+void 
+hfs_unlock_global (struct hfsmount *hfsmp) {
+       
+       void *thread = current_thread();
+
+    /* HFS_LOCK_EXCLUSIVE */
+       if (hfsmp->hfs_global_lockowner == thread) {
+               hfsmp->hfs_global_lockowner = NULL;
+               lck_rw_unlock_exclusive (&hfsmp->hfs_global_lock);
+       }
+    /* HFS_LOCK_SHARED */
+       else {
+               lck_rw_unlock_shared (&hfsmp->hfs_global_lock);
+       }
+}
+
 
 /*
  * Lock HFS system file(s).
  */
-__private_extern__
 int
 hfs_systemfile_lock(struct hfsmount *hfsmp, int flags, enum hfslocktype locktype)
 {
@@ -898,7 +1058,12 @@ hfs_systemfile_lock(struct hfsmount *hfsmp, int flags, enum hfslocktype locktype
                }
 #endif /* HFS_CHECK_LOCK_ORDER */
 
-               (void) hfs_lock(hfsmp->hfs_catalog_cp, locktype);
+               if (hfsmp->hfs_catalog_cp) {
+                       (void) hfs_lock(hfsmp->hfs_catalog_cp, locktype);
+               } else {
+                       flags &= ~SFL_CATALOG;
+               }
+
                /*
                 * When the catalog file has overflow extents then
                 * also acquire the extents b-tree lock if its not
@@ -942,7 +1107,12 @@ hfs_systemfile_lock(struct hfsmount *hfsmp, int flags, enum hfslocktype locktype
                }
 #endif /* HFS_CHECK_LOCK_ORDER */
 
-               (void) hfs_lock(hfsmp->hfs_startup_cp, locktype);
+               if (hfsmp->hfs_startup_cp) {
+                       (void) hfs_lock(hfsmp->hfs_startup_cp, locktype);
+               } else {
+                       flags &= ~SFL_STARTUP;
+               }
+
                /*
                 * When the startup file has overflow extents then
                 * also acquire the extents b-tree lock if its not
@@ -959,17 +1129,14 @@ hfs_systemfile_lock(struct hfsmount *hfsmp, int flags, enum hfslocktype locktype
         */
        if (flags & (SFL_BITMAP | SFL_EXTENTS)) {
                /*
-                * Since the only bitmap operations are clearing and
-                * setting bits we always need exclusive access. And
-                * when we have a journal, we can "hide" behind that
-                * lock since we can only change the bitmap from
-                * within a transaction.
+                * If there's no bitmap cnode, ignore the bitmap lock.
                 */
-               if (hfsmp->jnl || (hfsmp->hfs_allocation_cp == NULL)) {
+               if (hfsmp->hfs_allocation_cp == NULL) {
                        flags &= ~SFL_BITMAP;
                } else {
                        (void) hfs_lock(hfsmp->hfs_allocation_cp, HFS_EXCLUSIVE_LOCK);
-                       /* The bitmap lock is also grabbed when only extent lock 
+                       /* 
+                        * The bitmap lock is also grabbed when only extent lock 
                         * was requested. Set the bitmap lock bit in the lock
                         * flags which callers will use during unlock.
                         */
@@ -981,7 +1148,11 @@ hfs_systemfile_lock(struct hfsmount *hfsmp, int flags, enum hfslocktype locktype
                 * Since the extents btree lock is recursive we always
                 * need exclusive access.
                 */
-               (void) hfs_lock(hfsmp->hfs_extents_cp, HFS_EXCLUSIVE_LOCK);
+               if (hfsmp->hfs_extents_cp) {
+                       (void) hfs_lock(hfsmp->hfs_extents_cp, HFS_EXCLUSIVE_LOCK);
+               } else {
+                       flags &= ~SFL_EXTENTS;
+               }
        }
        return (flags);
 }
@@ -989,7 +1160,6 @@ hfs_systemfile_lock(struct hfsmount *hfsmp, int flags, enum hfslocktype locktype
 /*
  * unlock HFS system file(s).
  */
-__private_extern__
 void
 hfs_systemfile_unlock(struct hfsmount *hfsmp, int flags)
 {
@@ -1016,7 +1186,7 @@ hfs_systemfile_unlock(struct hfsmount *hfsmp, int flags)
                }
                hfs_unlock(hfsmp->hfs_attribute_cp);
        }
-       if (flags & SFL_CATALOG) {
+       if (flags & SFL_CATALOG && hfsmp->hfs_catalog_cp) {
                if (hfsmp->jnl == NULL) {
                        BTGetLastSync((FCB*)VTOF(hfsmp->hfs_catalog_vp), &lastfsync);
                        numOfLockedBuffs = count_lock_queue();
@@ -1028,10 +1198,10 @@ hfs_systemfile_unlock(struct hfsmount *hfsmp, int flags)
                }
                hfs_unlock(hfsmp->hfs_catalog_cp);
        }
-       if (flags & SFL_BITMAP) {
+       if (flags & SFL_BITMAP && hfsmp->hfs_allocation_cp) {
                hfs_unlock(hfsmp->hfs_allocation_cp);
        }
-       if (flags & SFL_EXTENTS) {
+       if (flags & SFL_EXTENTS && hfsmp->hfs_extents_cp) {
                if (hfsmp->jnl == NULL) {
                        BTGetLastSync((FCB*)VTOF(hfsmp->hfs_extents_vp), &lastfsync);
                        numOfLockedBuffs = count_lock_queue();
@@ -1161,7 +1331,6 @@ u_int32_t BestBlockSizeFit(u_int32_t allocationBlockSize,
 }
 
 
-__private_extern__
 u_int32_t
 GetFileInfo(ExtendedVCB *vcb, __unused u_int32_t dirid, const char *name,
                        struct cat_attr *fattr, struct cat_fork *forkinfo)
@@ -1201,7 +1370,6 @@ GetFileInfo(ExtendedVCB *vcb, __unused u_int32_t dirid, const char *name,
  * If the volume was not cleanly unmounted then some of these may
  * have persisted and need to be removed.
  */
-__private_extern__
 void
 hfs_remove_orphans(struct hfsmount * hfsmp)
 {
@@ -1279,8 +1447,9 @@ hfs_remove_orphans(struct hfsmount * hfsmp)
                 */
                if (bcmp(tempname, filename, namelen) == 0) {
                        struct filefork dfork;
-                       struct filefork rfork;
+               struct filefork rfork;
                        struct cnode cnode;
+                       int mode = 0;
 
                        bzero(&dfork, sizeof(dfork));
                        bzero(&rfork, sizeof(rfork));
@@ -1337,8 +1506,10 @@ hfs_remove_orphans(struct hfsmount * hfsmp)
                                                fsize = 0;
                                        }
 
-                                       if (TruncateFileC(vcb, (FCB*)&dfork, fsize, false) != 0) {
-                                               printf("hfs: error truncting data fork!\n");
+                                       if (TruncateFileC(vcb, (FCB*)&dfork, fsize, 1, 0, 
+                                                                         cnode.c_attr.ca_fileid, false) != 0) {
+                                               printf("hfs: error truncating data fork!\n");
+
                                                break;
                                        }
 
@@ -1369,8 +1540,8 @@ hfs_remove_orphans(struct hfsmount * hfsmp)
                                rfork.ff_cp = &cnode;
                                cnode.c_datafork = NULL;
                                cnode.c_rsrcfork = &rfork;
-                               if (TruncateFileC(vcb, (FCB*)&rfork, 0, false) != 0) {
-                                       printf("hfs: error truncting rsrc fork!\n");
+                               if (TruncateFileC(vcb, (FCB*)&rfork, 0, 1, 1, cnode.c_attr.ca_fileid, false) != 0) {
+                                       printf("hfs: error truncating rsrc fork!\n");
                                        break;
                                }
                        }
@@ -1384,7 +1555,9 @@ hfs_remove_orphans(struct hfsmount * hfsmp)
                                break;
                        }
                        
-                       if (cnode.c_attr.ca_mode & S_IFDIR) {
+                       mode = cnode.c_attr.ca_mode & S_IFMT;
+
+                       if (mode == S_IFDIR) {
                                orphaned_dirs++;
                        }
                        else {
@@ -1393,7 +1566,7 @@ hfs_remove_orphans(struct hfsmount * hfsmp)
 
                        /* Update parent and volume counts */   
                        hfsmp->hfs_private_attr[FILE_HARDLINKS].ca_entries--;
-                       if (cnode.c_attr.ca_mode & S_IFDIR) {
+                       if (mode == S_IFDIR) {
                                DEC_FOLDERCOUNT(hfsmp, hfsmp->hfs_private_attr[FILE_HARDLINKS]);
                        }
 
@@ -1409,7 +1582,7 @@ hfs_remove_orphans(struct hfsmount * hfsmp)
                           Now that Catalog is unlocked, update the volume info, making
                           sure to differentiate between files and directories
                        */
-                       if (cnode.c_attr.ca_mode & S_IFDIR) {
+                       if (mode == S_IFDIR) {
                                hfs_volupdate(hfsmp, VOL_RMDIR, 0);
                        }
                        else{
@@ -1482,7 +1655,6 @@ u_int32_t logBlockSize;
        return logBlockSize;    
 }
 
-__private_extern__
 u_int32_t
 hfs_freeblks(struct hfsmount * hfsmp, int wantreserve)
 {
@@ -1510,7 +1682,7 @@ hfs_freeblks(struct hfsmount * hfsmp, int wantreserve)
        else
                freeblks = 0;
 
-#ifdef HFS_SPARSE_DEV
+#if HFS_SPARSE_DEV
        /* 
         * When the underlying device is sparse, check the
         * available space on the backing store volume.
@@ -1834,7 +2006,7 @@ journal_open_cb(const char *bsd_dev_name, const char *uuid_str, void *arg)
        // desired uuid so let's try to open the device for writing and
        // see if it works.  if it does, we'll use it.
        
-       NDINIT(&nd, LOOKUP, LOCKLEAF, UIO_SYSSPACE32, CAST_USER_ADDR_T(bsd_name), vfs_context_kernel());
+       NDINIT(&nd, LOOKUP, OP_LOOKUP, LOCKLEAF, UIO_SYSSPACE32, CAST_USER_ADDR_T(bsd_name), vfs_context_kernel());
        if ((error = namei(&nd))) {
                printf("hfs: journal open cb: error %d looking up device %s (dev uuid %s)\n", error, bsd_name, uuid_str);
                return 1;   // keep iterating
@@ -1881,7 +2053,6 @@ journal_open_cb(const char *bsd_dev_name, const char *uuid_str, void *arg)
 
 extern dev_t IOBSDGetMediaWithUUID(const char *uuid_cstring, char *bsd_name, int bsd_name_len, int timeout);
 extern void IOBSDIterateMediaWithContent(const char *uuid_cstring, int (*func)(const char *bsd_dev_name, const char *uuid_str, void *arg), void *arg);
-extern kern_return_t IOBSDGetPlatformUUID(__darwin_uuid_t uuid, mach_timespec_t timeoutp);
 kern_return_t IOBSDGetPlatformSerialNumber(char *serial_number_str, u_int32_t len);
 
 
@@ -1933,7 +2104,6 @@ open_journal_dev(const char *vol_device,
 }
 
 
-__private_extern__
 int
 hfs_early_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                           void *_args, off_t embeddedOffset, daddr64_t mdb_offset,
@@ -2056,6 +2226,8 @@ hfs_early_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                                                        arg_flags,
                                                                        arg_tbufsz,
                                                                        hfs_sync_metadata, hfsmp->hfs_mp);
+               if (hfsmp->jnl)
+                       journal_trim_set_callback(hfsmp->jnl, hfs_trim_callback, hfsmp);
 
                // no need to start a transaction here... if this were to fail
                // we'd just re-init it on the next mount.
@@ -2077,6 +2249,8 @@ hfs_early_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp,
                                                                  arg_flags,
                                                                  arg_tbufsz,
                                                                  hfs_sync_metadata, hfsmp->hfs_mp);
+               if (hfsmp->jnl)
+                       journal_trim_set_callback(hfsmp->jnl, hfs_trim_callback, hfsmp);
 
                if (write_jibp) {
                        buf_bwrite(jinfo_bp);
@@ -2316,6 +2490,8 @@ hfs_late_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp, void *_a
                                                                        arg_flags,
                                                                        arg_tbufsz,
                                                                        hfs_sync_metadata, hfsmp->hfs_mp);
+               if (hfsmp->jnl)
+                       journal_trim_set_callback(hfsmp->jnl, hfs_trim_callback, hfsmp);
 
                // no need to start a transaction here... if this were to fail
                // we'd just re-init it on the next mount.
@@ -2345,6 +2521,8 @@ hfs_late_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp, void *_a
                                                                  arg_flags,
                                                                  arg_tbufsz,
                                                                  hfs_sync_metadata, hfsmp->hfs_mp);
+               if (hfsmp->jnl)
+                       journal_trim_set_callback(hfsmp->jnl, hfs_trim_callback, hfsmp);
        }
                        
 
@@ -2401,8 +2579,15 @@ hfs_late_journal_init(struct hfsmount *hfsmp, HFSPlusVolumeHeader *vhp, void *_a
 #define HOTBAND_MINIMUM_SIZE  (10*1024*1024)
 #define HOTBAND_MAXIMUM_SIZE  (512*1024*1024)
 
+/* Initialize the metadata zone.
+ *
+ * If the size of  the volume is less than the minimum size for
+ * metadata zone, metadata zone is disabled.
+ *
+ * If disable is true, disable metadata zone unconditionally.
+ */
 void
-hfs_metadatazone_init(struct hfsmount *hfsmp)
+hfs_metadatazone_init(struct hfsmount *hfsmp, int disable)
 {
        ExtendedVCB  *vcb;
        u_int64_t  fs_size;
@@ -2429,6 +2614,11 @@ hfs_metadatazone_init(struct hfsmount *hfsmp)
                really_do_it = 0;
        }
 
+       /* If caller wants to disable metadata zone, do it */
+       if (disable == true) {
+               really_do_it = 0;
+       }
+
        /*
         * Start with space for the boot blocks and Volume Header.
         * 1536 = byte offset from start of volume to end of volume header:
@@ -2619,7 +2809,6 @@ hfs_hotfile_freeblocks(struct hfsmount *hfsmp)
  * Determine if a file is a "virtual" metadata file.
  * This includes journal and quota files.
  */
-__private_extern__
 int
 hfs_virtualmetafile(struct cnode *cp)
 {
@@ -2691,7 +2880,6 @@ hfs_sync_ejectable(struct hfsmount *hfsmp)
 }
 
 
-__private_extern__
 int
 hfs_start_transaction(struct hfsmount *hfsmp)
 {
@@ -2716,11 +2904,11 @@ hfs_start_transaction(struct hfsmount *hfsmp)
        }
 #endif /* HFS_CHECK_LOCK_ORDER */
 
-    if (hfsmp->jnl == NULL || journal_owner(hfsmp->jnl) != thread) {
-       lck_rw_lock_shared(&hfsmp->hfs_global_lock);
-       OSAddAtomic(1, (SInt32 *)&hfsmp->hfs_active_threads);
-       unlock_on_err = 1;
-    }
+       if (hfsmp->jnl == NULL || journal_owner(hfsmp->jnl) != thread) {
+               hfs_lock_global (hfsmp, HFS_SHARED_LOCK);
+               OSAddAtomic(1, (SInt32 *)&hfsmp->hfs_active_threads);
+               unlock_on_err = 1;
+       }
 
        /* If a downgrade to read-only mount is in progress, no other
         * process than the downgrade process is allowed to modify 
@@ -2732,67 +2920,89 @@ hfs_start_transaction(struct hfsmount *hfsmp)
                goto out;
        }
 
-    if (hfsmp->jnl) {
-       ret = journal_start_transaction(hfsmp->jnl);
-       if (ret == 0) {
-           OSAddAtomic(1, &hfsmp->hfs_global_lock_nesting);
+       if (hfsmp->jnl) {
+               ret = journal_start_transaction(hfsmp->jnl);
+               if (ret == 0) {
+                       OSAddAtomic(1, &hfsmp->hfs_global_lock_nesting);
+               }
+       } else {
+               ret = 0;
        }
-    } else {
-       ret = 0;
-    }
 
 out:
-    if (ret != 0 && unlock_on_err) {
-       lck_rw_unlock_shared(&hfsmp->hfs_global_lock);
-       OSAddAtomic(-1, (SInt32 *)&hfsmp->hfs_active_threads);
-    }
+       if (ret != 0 && unlock_on_err) {
+               hfs_unlock_global (hfsmp);
+               OSAddAtomic(-1, (SInt32 *)&hfsmp->hfs_active_threads);
+       }
 
     return ret;
 }
 
-__private_extern__
 int
 hfs_end_transaction(struct hfsmount *hfsmp)
 {
     int need_unlock=0, ret;
 
-    if (    hfsmp->jnl == NULL
-       || (   journal_owner(hfsmp->jnl) == current_thread()
+    if ((hfsmp->jnl == NULL) || ( journal_owner(hfsmp->jnl) == current_thread()
            && (OSAddAtomic(-1, &hfsmp->hfs_global_lock_nesting) == 1)) ) {
-
            need_unlock = 1;
     } 
 
-    if (hfsmp->jnl) {
-       ret = journal_end_transaction(hfsmp->jnl);
-    } else {
-       ret = 0;
-    }
+       if (hfsmp->jnl) {
+               ret = journal_end_transaction(hfsmp->jnl);
+       } else {
+               ret = 0;
+       }
 
-    if (need_unlock) {
-       OSAddAtomic(-1, (SInt32 *)&hfsmp->hfs_active_threads);
-       lck_rw_unlock_shared(&hfsmp->hfs_global_lock);
-       hfs_sync_ejectable(hfsmp);
-    }
+       if (need_unlock) {
+               OSAddAtomic(-1, (SInt32 *)&hfsmp->hfs_active_threads);
+               hfs_unlock_global (hfsmp);
+               hfs_sync_ejectable(hfsmp);
+       }
 
     return ret;
 }
 
 
-__private_extern__
+/* 
+ * Flush the contents of the journal to the disk. 
+ *
+ *  Input: 
+ *     wait_for_IO - 
+ *     If TRUE, wait to write in-memory journal to the disk 
+ *     consistently, and also wait to write all asynchronous 
+ *     metadata blocks to its corresponding locations
+ *     consistently on the disk.  This means that the journal 
+ *     is empty at this point and does not contain any 
+ *     transactions.  This is overkill in normal scenarios  
+ *     but is useful whenever the metadata blocks are required 
+ *     to be consistent on-disk instead of just the journal 
+ *     being consistent; like before live verification 
+ *     and live volume resizing.  
+ *
+ *     If FALSE, only wait to write in-memory journal to the 
+ *     disk consistently.  This means that the journal still 
+ *     contains uncommitted transactions and the file system 
+ *     metadata blocks in the journal transactions might be 
+ *     written asynchronously to the disk.  But there is no 
+ *     guarantee that they are written to the disk before 
+ *     returning to the caller.  Note that this option is 
+ *     sufficient for file system data integrity as it 
+ *     guarantees consistent journal content on the disk.
+ */
 int
-hfs_journal_flush(struct hfsmount *hfsmp)
+hfs_journal_flush(struct hfsmount *hfsmp, boolean_t wait_for_IO)
 {
        int ret;
-       
+
        /* Only peek at hfsmp->jnl while holding the global lock */
-       lck_rw_lock_shared(&hfsmp->hfs_global_lock);
+       hfs_lock_global (hfsmp, HFS_SHARED_LOCK);
        if (hfsmp->jnl) {
-               ret = journal_flush(hfsmp->jnl);
+               ret = journal_flush(hfsmp->jnl, wait_for_IO);
        } else {
                ret = 0;
        }
-       lck_rw_unlock_shared(&hfsmp->hfs_global_lock);
+       hfs_unlock_global (hfsmp);
        
        return ret;
 }
@@ -2817,7 +3027,6 @@ hfs_journal_flush(struct hfsmount *hfsmp)
  * unused nodes have been repaired.  A newer newfs_hfs will set this bit.
  * As will fsck_hfs when it repairs the unused nodes.
  */
-__private_extern__
 int hfs_erase_unused_nodes(struct hfsmount *hfsmp)
 {
        int result; 
@@ -2870,3 +3079,92 @@ int hfs_erase_unused_nodes(struct hfsmount *hfsmp)
 done:
        return result;
 }
+
+
+extern time_t snapshot_timestamp;
+
+int
+check_for_tracked_file(struct vnode *vp, time_t ctime, uint64_t op_type, void *arg)
+{
+       int tracked_error = 0, snapshot_error = 0;
+       
+       if (vp == NULL) {
+               return 0;
+       }
+       
+       if (VTOC(vp)->c_flags & UF_TRACKED) {
+               // the file has the tracked bit set, so send an event to the tracked-file handler
+               int error;
+               
+               // printf("hfs: tracked-file: encountered a file with the tracked bit set! (vp %p)\n", vp);
+               error = resolve_nspace_item(vp, op_type | NAMESPACE_HANDLER_TRACK_EVENT);
+               if (error) {
+                       if (error == EAGAIN) {
+                               printf("hfs: tracked-file: timed out waiting for namespace handler...\n");
+                               
+                       } else if (error == EINTR) {
+                               // printf("hfs: tracked-file: got a signal while waiting for namespace handler...\n");
+                               tracked_error = EINTR;
+                       }
+               }
+       }
+
+       if (ctime != 0 && snapshot_timestamp != 0 && (ctime <= snapshot_timestamp || vnode_needssnapshots(vp))) {
+               // the change time is within this epoch
+               int error;
+               
+               error = resolve_nspace_item_ext(vp, op_type | NAMESPACE_HANDLER_SNAPSHOT_EVENT, arg);
+               if (error == EDEADLK) {
+                       snapshot_error = 0;
+               } else if (error) {
+                       if (error == EAGAIN) {
+                               printf("hfs: cow-snapshot: timed out waiting for namespace handler...\n");
+                       } else if (error == EINTR) {
+                               // printf("hfs: cow-snapshot: got a signal while waiting for namespace handler...\n");
+                               snapshot_error = EINTR;
+                       }
+               }
+       }
+       
+       if (tracked_error) return tracked_error;
+       if (snapshot_error) return snapshot_error;
+       
+       return 0;
+}
+
+int
+check_for_dataless_file(struct vnode *vp, uint64_t op_type)
+{
+       int error;
+
+       if (vp == NULL || (VTOC(vp)->c_flags & UF_COMPRESSED) == 0 || VTOCMP(vp) == NULL || VTOCMP(vp)->cmp_type != DATALESS_CMPFS_TYPE) {
+               // there's nothing to do, it's not dataless
+               return 0;
+       }
+                       
+       // printf("hfs: dataless: encountered a file with the dataless bit set! (vp %p)\n", vp);
+       error = resolve_nspace_item(vp, op_type | NAMESPACE_HANDLER_NSPACE_EVENT);
+       if (error == EDEADLK && op_type == NAMESPACE_HANDLER_WRITE_OP) {
+               error = 0;
+       } else if (error) {
+               if (error == EAGAIN) {
+                       printf("hfs: dataless: timed out waiting for namespace handler...\n");
+                       // XXXdbg - return the fabled ENOTPRESENT (i.e. EJUKEBOX)?
+                       return 0;                               
+               } else if (error == EINTR) {
+                       // printf("hfs: dataless: got a signal while waiting for namespace handler...\n");
+                       return EINTR;
+               }
+       } else if (VTOC(vp)->c_flags & UF_COMPRESSED) {
+               //
+               // if we're here, the dataless bit is still set on the file 
+               // which means it didn't get handled.  we return an error
+               // but it's presently ignored by all callers of this function.
+               //
+               // XXXdbg - EDATANOTPRESENT is what we really need...
+               //
+               return EBADF;
+       }                               
+
+       return error;
+}