]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/hfs/hfs_xattr.c
xnu-1228.tar.gz
[apple/xnu.git] / bsd / hfs / hfs_xattr.c
index c795bf72aa0b04f7f2bf7ec556bb65d0f5422045..37dca768bd6a6a8c3905882e7f0bdaf7ff312fe0 100644 (file)
@@ -1,14 +1,19 @@
 /*
- * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2004-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/malloc.h>
+#include <sys/ubc.h>
 #include <sys/utfconv.h>
 #include <sys/vnode.h>
 #include <sys/xattr.h>
+#include <sys/fcntl.h>
+#include <sys/vnode_internal.h>
+#include <sys/kauth.h>
 
 #include "hfs.h"
 #include "hfs_cnode.h"
 #include "hfs_mount.h"
 #include "hfs_format.h"
 #include "hfs_endian.h"
+#include "hfs_btreeio.h"
+#include "hfs_fsctl.h"
 
 #include "hfscommon/headers/BTreesInternal.h"
 
+#define HFS_XATTR_VERBOSE  0
 
 #define  ATTRIBUTE_FILE_NODE_SIZE   8192
 
@@ -49,37 +61,145 @@ struct listattr_callback_state {
        size_t      size;
 };
 
-#define HFS_MAXATTRIBUTESIZE    (1024*1024)
+#define HFS_MAXATTRIBUTESIZE    (128 * 1024)
+#define HFS_MAXATTRBLKS         (32 * 1024)
+
 
 /* HFS Internal Names */
 #define        XATTR_EXTENDEDSECURITY_NAME   "system.extendedsecurity"
+#define XATTR_XATTREXTENTS_NAME              "system.xattrextents"
 
-
-#define RESOURCE_FORK_EXISTS(VP)   \
-       ((VTOC((VP))->c_blocks - VTOF((VP))->ff_blocks) > 0)
+/* Faster version if we already know this is the data fork. */
+#define RSRC_FORK_EXISTS(CP)   \
+       (((CP)->c_attr.ca_blocks - (CP)->c_datafork->ff_data.cf_blocks) > 0)
 
 static u_int32_t emptyfinfo[8] = {0};
 
+const char hfs_attrdatafilename[] = "Attribute Data";
+
+static int  listattr_callback(const HFSPlusAttrKey *key, const HFSPlusAttrData *data,
+                       struct listattr_callback_state *state);
 
-extern int  hfs_create_attr_btree(struct hfsmount *hfsmp, uint32_t nodesize, uint32_t nodecnt);
+static int  remove_attribute_records(struct hfsmount *hfsmp, BTreeIterator * iterator);
 
+static int  getnodecount(struct hfsmount *hfsmp, size_t nodesize);
 
-int  hfs_vnop_getxattr(struct vnop_getxattr_args *ap);
-int  hfs_vnop_setxattr(struct vnop_setxattr_args *ap);
-int  hfs_vnop_removexattr(struct vnop_removexattr_args *ap);
-int  hfs_vnop_listxattr(struct vnop_listxattr_args *ap);
-int  hfs_attrkeycompare(HFSPlusAttrKey *searchKey, HFSPlusAttrKey *trialKey);
+static size_t  getmaxinlineattrsize(struct vnode * attrvp);
 
+static int  read_attr_data(struct hfsmount *hfsmp, uio_t uio, size_t datasize, HFSPlusExtentDescriptor *extents);
 
+static int  write_attr_data(struct hfsmount *hfsmp, uio_t uio, size_t datasize, HFSPlusExtentDescriptor *extents);
 
-static int  listattr_callback(const HFSPlusAttrKey *key, const HFSPlusAttrData *data,
-                       struct listattr_callback_state *state);
+static int  alloc_attr_blks(struct hfsmount *hfsmp, size_t attrsize, size_t extentbufsize, HFSPlusExtentDescriptor *extents, int *blocks);
 
-static int  buildkey(u_int32_t fileID, const char *attrname, HFSPlusAttrKey *key);
+static void  free_attr_blks(struct hfsmount *hfsmp, int blkcnt, HFSPlusExtentDescriptor *extents);
 
-static int  getnodecount(struct hfsmount *hfsmp, size_t nodesize);
+static int  has_overflow_extents(HFSPlusForkData *forkdata);
+
+static int  count_extent_blocks(int maxblks, HFSPlusExtentRecord extents);
+
+#if NAMEDSTREAMS
+/*
+ * Obtain the vnode for a stream.
+ */
+int
+hfs_vnop_getnamedstream(struct vnop_getnamedstream_args* ap)
+{
+       vnode_t vp = ap->a_vp;
+       vnode_t *svpp = ap->a_svpp;
+       struct cnode *cp;
+       int error = 0;
+
+       *svpp = NULL;
+
+       /*
+        * We only support the "com.apple.ResourceFork" stream.
+        */
+       if (bcmp(ap->a_name, XATTR_RESOURCEFORK_NAME, sizeof(XATTR_RESOURCEFORK_NAME)) != 0) {
+               return (ENOATTR);
+       }
+       cp = VTOC(vp);
+       if ( !S_ISREG(cp->c_mode) ) {
+               return (EPERM);
+       }
+       if ((error = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK))) {
+               return (error);
+       }
+       if (!RSRC_FORK_EXISTS(cp) && (ap->a_operation != NS_OPEN)) {
+               hfs_unlock(cp);
+               return (ENOATTR);
+       }
+       error = hfs_vgetrsrc(VTOHFS(vp), vp, svpp, TRUE);
+       hfs_unlock(cp);
+
+       return (error);
+}
+
+/*
+ * Create a stream.
+ */
+int
+hfs_vnop_makenamedstream(struct vnop_makenamedstream_args* ap)
+{
+       vnode_t vp = ap->a_vp;
+       vnode_t *svpp = ap->a_svpp;
+       struct cnode *cp;
+       int error = 0;
+
+       *svpp = NULL;
+
+       /*
+        * We only support the "com.apple.ResourceFork" stream.
+        */
+       if (bcmp(ap->a_name, XATTR_RESOURCEFORK_NAME, sizeof(XATTR_RESOURCEFORK_NAME)) != 0) {
+               return (ENOATTR);
+       }
+       cp = VTOC(vp);
+       if ( !S_ISREG(cp->c_mode) ) {
+               return (EPERM);
+       }
+       if ((error = hfs_lock(cp, HFS_EXCLUSIVE_LOCK))) {
+               return (error);
+       }
+       error = hfs_vgetrsrc(VTOHFS(vp), vp, svpp, TRUE);
+       hfs_unlock(cp);
+
+       return (error);
+}
+
+/*
+ * Remove a stream.
+ */
+int
+hfs_vnop_removenamedstream(struct vnop_removenamedstream_args* ap)
+{
+       vnode_t svp = ap->a_svp;
+       struct cnode *scp;
+       int error = 0;
+
+       /*
+        * We only support the "com.apple.ResourceFork" stream.
+        */
+       if (bcmp(ap->a_name, XATTR_RESOURCEFORK_NAME, sizeof(XATTR_RESOURCEFORK_NAME)) != 0) {
+               return (ENOATTR);
+       }
+       scp = VTOC(svp);
+
+       /* Take truncate lock before taking cnode lock. */
+       hfs_lock_truncate(scp, TRUE);
+       if ((error = hfs_lock(scp, HFS_EXCLUSIVE_LOCK))) {
+               goto out;
+       }
+       if (VTOF(svp)->ff_size != 0) {
+               error = hfs_truncate(svp, 0, IO_NDELAY, 0, ap->a_context);
+       }
+       hfs_unlock(scp);
+out:
+       hfs_unlock_truncate(scp, TRUE);
+       return (error);
+}
+#endif
 
-static size_t  getmaxinlineattrsize(struct vnode * attrvp);
 
 /*
  * Retrieve the data of an extended attribute.
@@ -100,29 +220,42 @@ hfs_vnop_getxattr(struct vnop_getxattr_args *ap)
 */
 {
        struct vnode *vp = ap->a_vp;
+       struct cnode *cp;
        struct hfsmount *hfsmp;
        uio_t uio = ap->a_uio;
        struct BTreeIterator * iterator = NULL;
        struct filefork *btfile;
        FSBufferDescriptor btdata;
-       HFSPlusAttrData * datap = NULL;
+       HFSPlusAttrRecord * recp = NULL;
        size_t bufsize;
-       UInt16 datasize;
+       u_int16_t datasize;
        int lockflags;
        int result;
 
-       if (ap->a_name == NULL || ap->a_name[0] == '\0') {
-               return (EINVAL);  /* invalid name */
-       }
-       hfsmp = VTOHFS(vp);
-
-       if (!VNODE_IS_RSRC(vp)) {
+       cp = VTOC(vp);
+       if (vp == cp->c_vp) {
                /* Get the Finder Info. */
                if (bcmp(ap->a_name, XATTR_FINDERINFO_NAME, sizeof(XATTR_FINDERINFO_NAME)) == 0) {
+                       u_int8_t finderinfo[32];
                        bufsize = 32;
 
+                       if ((result = hfs_lock(cp, HFS_SHARED_LOCK))) {
+                               return (result);
+                       }
+                       /* Make a copy since we may not export all of it. */
+                       bcopy(cp->c_finderinfo, finderinfo, sizeof(finderinfo));
+                       hfs_unlock(cp);
+
+                       /* Don't expose a symlink's private type/creator. */
+                       if (vnode_islnk(vp)) {
+                               struct FndrFileInfo *fip;
+
+                               fip = (struct FndrFileInfo *)&finderinfo;
+                               fip->fdType = 0;
+                               fip->fdCreator = 0;
+                       }
                        /* If Finder Info is empty then it doesn't exist. */
-                       if (bcmp(VTOC(vp)->c_finderinfo, emptyfinfo, sizeof(emptyfinfo)) == 0) {
+                       if (bcmp(finderinfo, emptyfinfo, sizeof(emptyfinfo)) == 0) {
                                return (ENOATTR);
                        }
                        if (uio == NULL) {
@@ -132,7 +265,7 @@ hfs_vnop_getxattr(struct vnop_getxattr_args *ap)
                        if (uio_resid(uio) < bufsize)
                                return (ERANGE);
 
-                       result = uiomove((caddr_t) &VTOC(vp)->c_finderinfo , bufsize, uio);
+                       result = uiomove((caddr_t)&finderinfo , bufsize, uio);
 
                        return (result);
                }
@@ -140,13 +273,20 @@ hfs_vnop_getxattr(struct vnop_getxattr_args *ap)
                if (bcmp(ap->a_name, XATTR_RESOURCEFORK_NAME, sizeof(XATTR_RESOURCEFORK_NAME)) == 0) {
                        struct vnode *rvp = NULL;
 
-                       if ( !vnode_isreg(vp) ) {
+                       if ( !S_ISREG(cp->c_mode) ) {
                                return (EPERM);
                        }
-                       if ( !RESOURCE_FORK_EXISTS(vp)) {
+                       if ((result = hfs_lock(cp, HFS_EXCLUSIVE_LOCK))) {
+                               return (result);
+                       }
+                       if ( !RSRC_FORK_EXISTS(cp)) {
+                               hfs_unlock(cp);
                                return (ENOATTR);
                        }
-                       if ((result = hfs_vgetrsrc(hfsmp, vp, &rvp, vfs_context_proc(ap->a_context)))) {
+                       hfsmp = VTOHFS(vp);
+                       result = hfs_vgetrsrc(hfsmp, vp, &rvp, TRUE);
+                       hfs_unlock(cp);
+                       if (result) {
                                return (result);
                        }
                        if (uio == NULL) {
@@ -158,31 +298,46 @@ hfs_vnop_getxattr(struct vnop_getxattr_args *ap)
                        return (result);
                }
        }
+       hfsmp = VTOHFS(vp);
        /*
         * Standard HFS only supports native FinderInfo and Resource Forks.
         */
        if (hfsmp->hfs_flags & HFS_STANDARD) {
                return (EPERM);
        }
+
+       if ((result = hfs_lock(cp, HFS_SHARED_LOCK))) {
+               return (result);
+       }
        /* Bail if we don't have any extended attributes. */
        if ((hfsmp->hfs_attribute_vp == NULL) ||
-           (VTOC(vp)->c_attr.ca_recflags & kHFSHasAttributesMask) == 0) {
-               return (ENOATTR);
+           (cp->c_attr.ca_recflags & kHFSHasAttributesMask) == 0) {
+               result = ENOATTR;
+               goto exit;
        }
        btfile = VTOF(hfsmp->hfs_attribute_vp);
 
        MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               result = ENOMEM;
+               goto exit;
+       }
        bzero(iterator, sizeof(*iterator));
 
        bufsize = sizeof(HFSPlusAttrData) - 2;
        if (uio)
                bufsize += uio_resid(uio);
-       MALLOC(datap, HFSPlusAttrData *, bufsize, M_TEMP, M_WAITOK);
-       btdata.bufferAddress = datap;
+       bufsize = MAX(bufsize, sizeof(HFSPlusAttrRecord));
+       MALLOC(recp, HFSPlusAttrRecord *, bufsize, M_TEMP, M_WAITOK);
+       if (recp == NULL) {
+               result = ENOMEM;
+               goto exit;
+       }
+       btdata.bufferAddress = recp;
        btdata.itemSize = bufsize;
        btdata.itemCount = 1;
 
-       result = buildkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
+       result = hfs_buildattrkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
        if (result)
                goto exit;      
 
@@ -197,19 +352,123 @@ hfs_vnop_getxattr(struct vnop_getxattr_args *ap)
                goto exit;
        }
 
-       *ap->a_size = datap->attrSize;
+       switch (recp->recordType) {
+       case kHFSPlusAttrInlineData:
+               /*
+                * Sanity check record size. It's not required to have any
+                * user data, so the minimum size is 2 bytes less that the
+                * size of HFSPlusAttrData (since HFSPlusAttrData struct
+                * has 2 bytes set aside for attribute data).
+                */
+               if (datasize < (sizeof(HFSPlusAttrData) - 2)) {
+                       printf("hfs_getxattr: %d,%s invalid record size %d (expecting %lu)\n", 
+                               VTOC(vp)->c_fileid, ap->a_name, datasize, sizeof(HFSPlusAttrData));
+                       result = ENOATTR;
+                       break;
+               }
+               *ap->a_size = recp->attrData.attrSize;
+               if (uio && recp->attrData.attrSize != 0) {
+                       if (*ap->a_size > uio_resid(uio))
+                               result = ERANGE;
+                       else
+                               result = uiomove((caddr_t) &recp->attrData.attrData , recp->attrData.attrSize, uio);
+               }
+               break;
 
-       /* Copy out the attribute data. */
-       if (uio) {
-               if (datap->attrSize > uio_resid(uio))
+       case kHFSPlusAttrForkData:
+               if (datasize < sizeof(HFSPlusAttrForkData)) {
+                       printf("hfs_getxattr: %d,%s invalid record size %d (expecting %lu)\n", 
+                               VTOC(vp)->c_fileid, ap->a_name, datasize, sizeof(HFSPlusAttrForkData));
+                       result = ENOATTR;
+                       break;
+               }
+               *ap->a_size = recp->forkData.theFork.logicalSize;
+               if (uio == NULL) {
+                       break;
+               }
+               if (*ap->a_size > uio_resid(uio)) {
                        result = ERANGE;
-               else
-                       result = uiomove((caddr_t) &datap->attrData , datap->attrSize, uio);
+                       break;
+               }
+               /* Process overflow extents if necessary. */
+               if (has_overflow_extents(&recp->forkData.theFork)) {
+                       HFSPlusExtentDescriptor *extentbuf;
+                       HFSPlusExtentDescriptor *extentptr;
+                       size_t extentbufsize;
+                       u_int32_t totalblocks;
+                       u_int32_t blkcnt;
+                       u_int32_t attrlen;
+
+                       totalblocks = recp->forkData.theFork.totalBlocks;
+                       /* Ignore bogus block counts. */
+                       if (totalblocks > HFS_MAXATTRBLKS) {
+                               result = ERANGE;
+                               break;
+                       }
+                       attrlen = recp->forkData.theFork.logicalSize;
+
+                       /* Get a buffer to hold the worst case amount of extents. */
+                       extentbufsize = totalblocks * sizeof(HFSPlusExtentDescriptor);
+                       extentbufsize = roundup(extentbufsize, sizeof(HFSPlusExtentRecord));
+                       MALLOC(extentbuf, HFSPlusExtentDescriptor *, extentbufsize, M_TEMP, M_WAITOK);
+                       if (extentbuf == NULL) {
+                               result = ENOMEM;
+                               break;
+                       }
+                       bzero(extentbuf, extentbufsize);
+                       extentptr = extentbuf;
+
+                       /* Grab the first 8 extents. */
+                       bcopy(&recp->forkData.theFork.extents[0], extentptr, sizeof(HFSPlusExtentRecord));
+                       extentptr += kHFSPlusExtentDensity;
+                       blkcnt = count_extent_blocks(totalblocks, recp->forkData.theFork.extents);
+
+                       /* Now lookup the overflow extents. */
+                       lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE, HFS_SHARED_LOCK);
+                       while (blkcnt < totalblocks) {
+                               ((HFSPlusAttrKey *)&iterator->key)->startBlock = blkcnt;
+                               result = BTSearchRecord(btfile, iterator, &btdata, &datasize, NULL);
+                               if (result ||
+                                   (recp->recordType != kHFSPlusAttrExtents) ||
+                                   (datasize < sizeof(HFSPlusAttrExtents))) {
+                                       printf("hfs_getxattr: %s missing extents, only %d blks of %d found\n",
+                                               ap->a_name, blkcnt, totalblocks);
+                                       result = ENOATTR;
+                                       break;   /* break from while */
+                               }
+                               /* Grab the next 8 extents. */
+                               bcopy(&recp->overflowExtents.extents[0], extentptr, sizeof(HFSPlusExtentRecord));
+                               extentptr += kHFSPlusExtentDensity;
+                               blkcnt += count_extent_blocks(totalblocks, recp->overflowExtents.extents);
+                       }
+                       hfs_systemfile_unlock(hfsmp, lockflags);
+
+                       if (blkcnt < totalblocks) {
+                               result = ENOATTR;
+                       } else {
+                               result = read_attr_data(hfsmp, uio, attrlen, extentbuf);
+                       }
+                       FREE(extentbuf, M_TEMP);
+
+               } else /* No overflow extents. */ {
+                       result = read_attr_data(hfsmp, uio, recp->forkData.theFork.logicalSize, recp->forkData.theFork.extents);
+               }
+               break;
+
+       default:
+               result = ENOATTR;
+               break;          
        }
 exit:
-       FREE(datap, M_TEMP);
-       FREE(iterator, M_TEMP);
+       hfs_unlock(cp);
 
+       if (iterator) {
+               FREE(iterator, M_TEMP);
+       }
+       if (recp) {
+               FREE(recp, M_TEMP);
+       }
+       
        return MacToVFSError(result);
 }
 
@@ -231,15 +490,21 @@ hfs_vnop_setxattr(struct vnop_setxattr_args *ap)
 */
 {
        struct vnode *vp = ap->a_vp;
+       struct cnode *cp = NULL;
        struct hfsmount *hfsmp;
        uio_t uio = ap->a_uio;
        struct BTreeIterator * iterator = NULL;
-       struct filefork *btfile;
+       struct filefork *btfile = NULL;
        size_t attrsize;
        FSBufferDescriptor btdata;
-       HFSPlusAttrData * datap = NULL;
-       UInt16 datasize;
-       int lockflags;
+       HFSPlusAttrRecord *recp = NULL;
+       HFSPlusExtentDescriptor *extentptr = NULL;
+       HFSPlusAttrRecord attrdata;  /* 90 bytes */
+       void * user_data_ptr = NULL;
+       int started_transaction = 0;
+       int lockflags = 0;
+       int exists;
+       int allocatedblks = 0;
        int result;
 
        if (ap->a_name == NULL || ap->a_name[0] == '\0') {
@@ -251,28 +516,83 @@ hfs_vnop_setxattr(struct vnop_setxattr_args *ap)
        }
        /* Set the Finder Info. */
        if (bcmp(ap->a_name, XATTR_FINDERINFO_NAME, sizeof(XATTR_FINDERINFO_NAME)) == 0) {
-               attrsize = 32;
+               u_int8_t finderinfo[32];
+               struct FndrFileInfo *fip;
+               void * finderinfo_start;
+               u_int16_t fdFlags;
+
+               attrsize = sizeof(VTOC(vp)->c_finderinfo);
+
+               if (uio_resid(uio) != attrsize) {
+                       return (ERANGE);
+               }
+               /* Grab the new Finder Info data. */
+               if ((result = uiomove((caddr_t)&finderinfo , attrsize, uio))) {
+                       return (result);
+               }
+               fip = (struct FndrFileInfo *)&finderinfo;
+
+               if ((result = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK))) {
+                       return (result);
+               }
+               cp = VTOC(vp);
+
+               /* Symlink's don't have an external type/creator. */
+               if (vnode_islnk(vp)) {
+                       /* Skip over type/creator fields. */
+                       finderinfo_start = &cp->c_finderinfo[8];
+                       attrsize -= 8;
+               } else {
+                       finderinfo_start = &cp->c_finderinfo[0];
+                       /*
+                        * Don't allow the external setting of
+                        * file type to kHardLinkFileType.
+                        */
+                       if (fip->fdType == SWAP_BE32(kHardLinkFileType)) {
+                               hfs_unlock(cp);
+                               return (EPERM);
+                       } 
+               }
 
-               if (bcmp(VTOC(vp)->c_finderinfo, emptyfinfo, sizeof(emptyfinfo))) {
+               if (bcmp(finderinfo_start, emptyfinfo, attrsize)) {
                        /* attr exists and "create" was specified. */
                        if (ap->a_options & XATTR_CREATE) {
+                               hfs_unlock(cp);
                                return (EEXIST);
                        }
-               } else {
+               } else /* empty */ {
                        /* attr doesn't exists and "replace" was specified. */
                        if (ap->a_options & XATTR_REPLACE) {
+                               hfs_unlock(cp);
                                return (ENOATTR);
                        }
                }
-               if (uio_resid(uio) != attrsize)
-                       return (ERANGE);
+               /* Set the cnode's Finder Info. */
+               if (attrsize == sizeof(cp->c_finderinfo))
+                       bcopy(&finderinfo[0], finderinfo_start, attrsize);
+               else
+                       bcopy(&finderinfo[8], finderinfo_start, attrsize);
 
-               result = uiomove((caddr_t) &VTOC(vp)->c_finderinfo , attrsize, uio);
-               if (result == 0) {
-                       VTOC(vp)->c_touch_chgtime = TRUE;
-                       VTOC(vp)->c_flag |= C_MODIFIED;
-                       result = hfs_update(vp, FALSE);
-               }
+               /* Updating finderInfo updates change time and modified time */
+               cp->c_touch_chgtime = TRUE;
+               cp->c_flag |= C_MODIFIED;
+
+               /*
+                * Mirror the invisible bit to the UF_HIDDEN flag.
+                *
+                * The fdFlags for files and frFlags for folders are both 8 bytes
+                * into the userInfo (the first 16 bytes of the Finder Info).  They
+                * are both 16-bit fields.
+                */
+               fdFlags = *((u_int16_t *) &cp->c_finderinfo[8]);
+               if (fdFlags & OSSwapHostToBigConstInt16(kFinderInvisibleMask))
+                       cp->c_flags |= UF_HIDDEN;
+               else
+                       cp->c_flags &= ~UF_HIDDEN;
+
+               result = hfs_update(vp, FALSE);
+
+               hfs_unlock(cp);
                return (result);
        }
        /* Write the Resource Fork. */
@@ -282,20 +602,30 @@ hfs_vnop_setxattr(struct vnop_setxattr_args *ap)
                if (!vnode_isreg(vp)) {
                        return (EPERM);
                }
-               if (RESOURCE_FORK_EXISTS(vp)) {
+               if ((result = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK))) {
+                       return (result);
+               }
+               cp = VTOC(vp);
+
+               if (RSRC_FORK_EXISTS(cp)) {
                        /* attr exists and "create" was specified. */
                        if (ap->a_options & XATTR_CREATE) {
+                               hfs_unlock(cp);
                                return (EEXIST);
                        }
                } else {
                        /* attr doesn't exists and "replace" was specified. */
                        if (ap->a_options & XATTR_REPLACE) {
+                               hfs_unlock(cp);
                                return (ENOATTR);
                        }
                }
-               if ((result = hfs_vgetrsrc(hfsmp, vp, &rvp, vfs_context_proc(ap->a_context)))) {
+               result = hfs_vgetrsrc(hfsmp, vp, &rvp, TRUE);
+               hfs_unlock(cp);
+               if (result) {
                        return (result);
                }
+               /* VNOP_WRITE will update timestamps accordingly */
                result = VNOP_WRITE(rvp, uio, 0, ap->a_context);
                vnode_put(rvp);
                return (result);
@@ -306,123 +636,279 @@ hfs_vnop_setxattr(struct vnop_setxattr_args *ap)
        if (hfsmp->hfs_flags & HFS_STANDARD) {
                return (EPERM);
        }
-       if (hfsmp->hfs_max_inline_attrsize == 0) {
-               hfsmp->hfs_max_inline_attrsize = getmaxinlineattrsize(hfsmp->hfs_attribute_vp);
-       }
        attrsize = uio_resid(uio);
-       if (attrsize > hfsmp->hfs_max_inline_attrsize) {
-               /*
-                * XXX Need to support extent-based attributes XXX
-                */
+
+       /* Enforce an upper limit. */
+       if (attrsize > HFS_MAXATTRIBUTESIZE) {
                return (E2BIG);
        }
-       /* Calculate size of record rounded up to multiple of 2 bytes. */
-       datasize = sizeof(HFSPlusAttrData) - 2 + attrsize + ((attrsize & 1) ? 1 : 0);
-
-       MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
-       bzero(iterator, sizeof(*iterator));
 
-       MALLOC(datap, HFSPlusAttrData *, datasize, M_TEMP, M_WAITOK);
-       btdata.bufferAddress = datap;
-       btdata.itemSize = datasize;
-       btdata.itemCount = 1;
-       datap->recordType = kHFSPlusAttrInlineData;
-       datap->reserved[0] = 0;
-       datap->reserved[1] = 0;
-       datap->attrSize = attrsize;
+       /*
+        * Attempt to copy the users attr data before taking any locks.
+        */
+       if (attrsize > 0 &&
+           hfsmp->hfs_max_inline_attrsize != 0 &&
+           attrsize < hfsmp->hfs_max_inline_attrsize) {
+               MALLOC(user_data_ptr, void *, attrsize, M_TEMP, M_WAITOK);
+               if (user_data_ptr == NULL) {
+                       return (ENOMEM);
+               }
 
-       /* Copy in the attribute data. */
-       result = uiomove((caddr_t) &datap->attrData , attrsize, uio);
-       if (result) {
-               goto exit2;
+               result = uiomove((caddr_t)user_data_ptr, attrsize, uio);
+               if (result) {
+                       goto exit;
+               }
        }
-       /* Build a b-tree key. */
-       result = buildkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
+
+       result = hfs_lock(VTOC(vp), HFS_EXCLUSIVE_LOCK);
        if (result) {
-               goto exit2;
+               goto exit;
        }
+       cp = VTOC(vp);
+
        /* Start a transaction for our changes. */
        if (hfs_start_transaction(hfsmp) != 0) {
            result = EINVAL;
-           goto exit2;
+           goto exit;
        }
+       started_transaction = 1;
 
-       /* once we started the transaction, nobody can compete with us, so make sure this file is still there */
-       struct cnode *cp;
-       cp = VTOC(vp);
-       if (cp->c_flag & C_NOEXISTS) {                           /* this file has already been removed */
+       /*
+        * Once we started the transaction, nobody can compete
+        * with us, so make sure this file is still there.
+        */
+       if (cp->c_flag & C_NOEXISTS) {
                result = ENOENT;
-               goto exit1;
+               goto exit;
        }
 
        /*
         * If there isn't an attributes b-tree then create one.
         */
        if (hfsmp->hfs_attribute_vp == NULL) {
-               lockflags = hfs_systemfile_lock(hfsmp, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK);
                result = hfs_create_attr_btree(hfsmp, ATTRIBUTE_FILE_NODE_SIZE,
                                               getnodecount(hfsmp, ATTRIBUTE_FILE_NODE_SIZE));
-               hfs_systemfile_unlock(hfsmp, lockflags);
                if (result) {
-                       goto exit1;
+                       goto exit;
                }
        }
-       btfile = VTOF(hfsmp->hfs_attribute_vp);
+       if (hfsmp->hfs_max_inline_attrsize == 0) {
+               hfsmp->hfs_max_inline_attrsize = getmaxinlineattrsize(hfsmp->hfs_attribute_vp);
+       }
 
+       /* Take exclusive access to the attributes b-tree. */
        lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK);
 
-       if (ap->a_options & XATTR_REPLACE) {
-               result = BTReplaceRecord(btfile, iterator, &btdata, datasize);
-               if (result)
-                       goto exit0;
-               else
-                       goto exit;
+       /* Build the b-tree key. */
+       MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               result = ENOMEM;
+               goto exit;
        }
-
-       /* Insert the attribute. */
-       result = BTInsertRecord(btfile, iterator, &btdata, datasize);
+       bzero(iterator, sizeof(*iterator));
+       result = hfs_buildattrkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
        if (result) {
-               if (result != btExists) {
-                       goto exit0;
+               goto exit;
+       }
+
+       /* Preflight for replace/create semantics. */
+       btfile = VTOF(hfsmp->hfs_attribute_vp);
+       btdata.bufferAddress = &attrdata;
+       btdata.itemSize = sizeof(attrdata);
+       btdata.itemCount = 1;
+       exists = BTSearchRecord(btfile, iterator, &btdata, NULL, NULL) == 0;
+
+       /* Replace requires that the attribute already exists. */
+       if ((ap->a_options & XATTR_REPLACE) && !exists) {
+               result = ENOATTR;
+               goto exit;      
+       }
+       /* Create requires that the attribute doesn't exist. */
+       if ((ap->a_options & XATTR_CREATE) && exists) {
+               result = EEXIST;
+               goto exit;      
+       }
+       /* If it won't fit inline then use extent-based attributes. */
+       if (attrsize > hfsmp->hfs_max_inline_attrsize) {
+               size_t extentbufsize;
+               int blkcnt;
+               int extentblks;
+               u_int32_t *keystartblk;
+               int i;
+
+               /* Check if volume supports extent-based attributes */
+               if ((hfsmp->hfs_flags & HFS_XATTR_EXTENTS) == 0) {
+                       result = E2BIG;
+                       goto exit;
+               } 
+
+               /* Get some blocks. */
+               blkcnt = howmany(attrsize, hfsmp->blockSize);
+               extentbufsize = blkcnt * sizeof(HFSPlusExtentDescriptor);
+               extentbufsize = roundup(extentbufsize, sizeof(HFSPlusExtentRecord));
+               MALLOC(extentptr, HFSPlusExtentDescriptor *, extentbufsize, M_TEMP, M_WAITOK);
+               if (extentptr == NULL) {
+                       result = ENOMEM;
+                       goto exit;
+               }
+               bzero(extentptr, extentbufsize);
+               result = alloc_attr_blks(hfsmp, attrsize, extentbufsize, extentptr, &allocatedblks);
+               if (result) {
+                       allocatedblks = 0;
+                       goto exit;  /* no more space */
+               }
+               /* Copy data into the blocks. */
+               result = write_attr_data(hfsmp, uio, attrsize, extentptr);
+               if (result) {
+                       printf("hfs_setxattr: write_attr_data err (%d) %s:%s\n",
+                               result, vnode_name(vp) ? vnode_name(vp) : "", ap->a_name);
+                       goto exit;
+               }
+
+               /* Now remove any previous attribute. */
+               if (exists) {
+                       result = remove_attribute_records(hfsmp, iterator);
+                       if (result) {
+                               printf("hfs_setxattr: remove_attribute_records err (%d) %s:%s\n",
+                                       result, vnode_name(vp) ? vnode_name(vp) : "", ap->a_name);
+                               goto exit; 
+                       }
+               }
+
+               /* Create attribute fork data record. */
+               MALLOC(recp, HFSPlusAttrRecord *, sizeof(HFSPlusAttrRecord), M_TEMP, M_WAITOK);
+               if (recp == NULL) {
+                       result = ENOMEM;
+                       goto exit;
+               }
+               btdata.bufferAddress = recp;
+               btdata.itemCount = 1;
+               btdata.itemSize = sizeof(HFSPlusAttrForkData);
+
+               recp->recordType = kHFSPlusAttrForkData;
+               recp->forkData.reserved = 0;
+               recp->forkData.theFork.logicalSize = attrsize;
+               recp->forkData.theFork.clumpSize = 0;
+               recp->forkData.theFork.totalBlocks = blkcnt;
+               bcopy(extentptr, recp->forkData.theFork.extents, sizeof(HFSPlusExtentRecord));
+
+               (void) hfs_buildattrkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
+
+               result = BTInsertRecord(btfile, iterator, &btdata, btdata.itemSize);
+               if (result) {
+#if HFS_XATTR_VERBOSE
+                       printf("hfs_setxattr: BTInsertRecord err (%d) %s:%s\n",
+                              MacToVFSError(result), vnode_name(vp) ? vnode_name(vp) : "", ap->a_name);
+#endif
+                       goto exit; 
+               }
+               extentblks = count_extent_blocks(blkcnt, recp->forkData.theFork.extents);
+               blkcnt -= extentblks;
+               keystartblk = &((HFSPlusAttrKey *)&iterator->key)->startBlock;
+               i = 0;
+
+               /* Create overflow extents as needed. */
+               while (blkcnt > 0) {
+                       /* Initialize the key and record. */
+                       *keystartblk += (u_int32_t)extentblks;
+                       btdata.itemSize = sizeof(HFSPlusAttrExtents);
+                       recp->recordType = kHFSPlusAttrExtents;
+                       recp->overflowExtents.reserved = 0;
+
+                       /* Copy the next set of extents. */
+                       i += kHFSPlusExtentDensity;
+                       bcopy(&extentptr[i], recp->overflowExtents.extents, sizeof(HFSPlusExtentRecord));
+
+                       result = BTInsertRecord(btfile, iterator, &btdata, btdata.itemSize);
+                       if (result) {
+                               printf("hfs_setxattr: BTInsertRecord err (%d) %s:%s\n",
+                                       MacToVFSError(result), vnode_name(vp) ? vnode_name(vp) : "", ap->a_name);
+                               goto exit;
+                       }
+                       extentblks = count_extent_blocks(blkcnt, recp->overflowExtents.extents);
+                       blkcnt -= extentblks;
+               }
+       } else /* Inline data */ {
+               if (exists) {
+                       result = remove_attribute_records(hfsmp, iterator);
+                       if (result) {
+                               goto exit;
+                       }
                }
 
-               // if it exists and XATTR_CREATE was specified,
-               // the spec says to return EEXIST
-               if (ap->a_options & XATTR_CREATE) {
-                       result = EEXIST;
-                       goto exit0;
+               /* Calculate size of record rounded up to multiple of 2 bytes. */
+               btdata.itemSize = sizeof(HFSPlusAttrData) - 2 + attrsize + ((attrsize & 1) ? 1 : 0);
+               MALLOC(recp, HFSPlusAttrRecord *, btdata.itemSize, M_TEMP, M_WAITOK);
+               if (recp == NULL) {
+                       result = ENOMEM;
+                       goto exit;
+               }
+               recp->recordType = kHFSPlusAttrInlineData;
+               recp->attrData.reserved[0] = 0;
+               recp->attrData.reserved[1] = 0;
+               recp->attrData.attrSize = attrsize;
+       
+               /* Copy in the attribute data (if any). */
+               if (attrsize > 0) {
+                       if (user_data_ptr)
+                               bcopy(user_data_ptr, &recp->attrData.attrData, attrsize);
+                       else
+                               result = uiomove((caddr_t)&recp->attrData.attrData, attrsize, uio);
+                       if (result) {
+                               goto exit;
+                       }
                }
-               /* XXX need to account for old size in c_attrblks */
-               result = BTReplaceRecord(btfile, iterator, &btdata, datasize);
+
+               (void) hfs_buildattrkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
+
+               btdata.bufferAddress = recp;
+               btdata.itemCount = 1;
+               result = BTInsertRecord(btfile, iterator, &btdata, btdata.itemSize);
        }
 exit:
-       (void) BTFlushPath(btfile);
-exit0:
-       hfs_systemfile_unlock(hfsmp, lockflags);
+       if (btfile && started_transaction) {
+               (void) BTFlushPath(btfile);
+       }
+       if (lockflags) {
+               hfs_systemfile_unlock(hfsmp, lockflags);
+       }
        if (result == 0) {
-               struct cnode * cp;
-
                cp = VTOC(vp);
+               /* Setting an attribute only updates change time and not 
+                * modified time of the file.
+                */
                cp->c_touch_chgtime = TRUE;
-               if ((cp->c_attr.ca_recflags & kHFSHasAttributesMask) == 0) {
-                       cp->c_attr.ca_recflags |= kHFSHasAttributesMask;
-                       (void) hfs_update(vp, 0);
+               cp->c_attr.ca_recflags |= kHFSHasAttributesMask;
+               if ((bcmp(ap->a_name, KAUTH_FILESEC_XATTR, sizeof(KAUTH_FILESEC_XATTR)) == 0)) {
+                       cp->c_attr.ca_recflags |= kHFSHasSecurityMask;
                }
+               (void) hfs_update(vp, 0);
+       }
+       if (started_transaction) {
+               if (result && allocatedblks) {
+                       free_attr_blks(hfsmp, allocatedblks, extentptr);
+               }
+               hfs_end_transaction(hfsmp);
+       }
+       if (cp) {
+               hfs_unlock(cp);
+       }
+       if (result == 0) {
                HFS_KNOTE(vp, NOTE_ATTRIB);
        }
-exit1:
-       /* Finish the transaction of our changes. */
-       hfs_end_transaction(hfsmp);
-exit2:
-       FREE(datap, M_TEMP);
-       FREE(iterator, M_TEMP);
-
-       if (result == btNotFound)
-               result = ENOATTR;
-       else
-               result = MacToVFSError(result);
-
-       return (result);
+       if (user_data_ptr) {
+               FREE(user_data_ptr, M_TEMP);
+       }
+       if (recp) {
+               FREE(recp, M_TEMP);
+       }
+       if (extentptr) {
+               FREE(extentptr, M_TEMP);
+       }
+       if (iterator) {
+               FREE(iterator, M_TEMP);
+       }
+       return (result == btNotFound ? ENOATTR : MacToVFSError(result));
 }
 
 /*
@@ -442,12 +928,9 @@ hfs_vnop_removexattr(struct vnop_removexattr_args *ap)
 */
 {
        struct vnode *vp = ap->a_vp;
+       struct cnode *cp = VTOC(vp);
        struct hfsmount *hfsmp;
        struct BTreeIterator * iterator = NULL;
-       struct filefork *btfile;
-       struct proc *p = vfs_context_proc(ap->a_context);
-       FSBufferDescriptor btdata;
-       HFSPlusAttrData attrdata;
        int lockflags;
        int result;
 
@@ -466,21 +949,45 @@ hfs_vnop_removexattr(struct vnop_removexattr_args *ap)
                if ( !vnode_isreg(vp) ) {
                        return (EPERM);
                }
-               if ( !RESOURCE_FORK_EXISTS(vp) ) {
+               if ((result = hfs_lock(cp, HFS_EXCLUSIVE_LOCK))) {
+                       return (result);
+               }
+               if ( !RSRC_FORK_EXISTS(cp)) {
+                       hfs_unlock(cp);
                        return (ENOATTR);
                }
-               if ((result = hfs_vgetrsrc(hfsmp, vp, &rvp, p))) {
+               result = hfs_vgetrsrc(hfsmp, vp, &rvp, TRUE);
+               hfs_unlock(cp);
+               if (result) {
                        return (result);
                }
+
                hfs_lock_truncate(VTOC(rvp), TRUE);
                if ((result = hfs_lock(VTOC(rvp), HFS_EXCLUSIVE_LOCK))) {
-                       hfs_unlock_truncate(VTOC(vp));
+                       hfs_unlock_truncate(cp, TRUE);
+                       vnode_put(rvp);
+                       return (result);
+               }
+
+               /* Start a transaction for encapsulating changes in 
+                * hfs_truncate() and hfs_update()
+                */
+               if ((result = hfs_start_transaction(hfsmp))) {
+                       hfs_unlock_truncate(cp, TRUE);
+                       hfs_unlock(cp);
                        vnode_put(rvp);
                        return (result);
                }
+
                result = hfs_truncate(rvp, (off_t)0, IO_NDELAY, 0, ap->a_context);
+               if (result == 0) {
+                       cp->c_touch_chgtime = TRUE;
+                       cp->c_flag |= C_MODIFIED;
+                       result = hfs_update(vp, FALSE);
+               }
 
-               hfs_unlock_truncate(VTOC(rvp));
+               hfs_end_transaction(hfsmp);
+               hfs_unlock_truncate(VTOC(rvp), TRUE);
                hfs_unlock(VTOC(rvp));
 
                vnode_put(rvp);
@@ -488,10 +995,36 @@ hfs_vnop_removexattr(struct vnop_removexattr_args *ap)
        }
        /* Clear out the Finder Info. */
        if (bcmp(ap->a_name, XATTR_FINDERINFO_NAME, sizeof(XATTR_FINDERINFO_NAME)) == 0) {
-               if (bcmp(VTOC(vp)->c_finderinfo, emptyfinfo, sizeof(emptyfinfo)) == 0) {
+               void * finderinfo_start;
+               int finderinfo_size;
+
+               if ((result = hfs_lock(cp, HFS_EXCLUSIVE_LOCK))) {
+                       return (result);
+               }
+
+               /* Symlink's don't have an external type/creator. */
+               if (vnode_islnk(vp)) {
+                       /* Skip over type/creator fields. */
+                       finderinfo_start = &cp->c_finderinfo[8];
+                       finderinfo_size = sizeof(cp->c_finderinfo) - 8;
+               } else {
+                       finderinfo_start = &cp->c_finderinfo[0];
+                       finderinfo_size = sizeof(cp->c_finderinfo);
+               }
+               if (bcmp(finderinfo_start, emptyfinfo, finderinfo_size) == 0) {
+                       hfs_unlock(cp);
                        return (ENOATTR);
                }
-               bzero(VTOC(vp)->c_finderinfo, sizeof(emptyfinfo));
+
+               bzero(finderinfo_start, finderinfo_size);
+
+               /* Updating finderInfo updates change time and modified time */
+               cp->c_touch_chgtime = TRUE;
+               cp->c_flag |= C_MODIFIED;
+               hfs_update(vp, FALSE);
+
+               hfs_unlock(cp);
+
                return (0);
        }
        /*
@@ -503,46 +1036,211 @@ hfs_vnop_removexattr(struct vnop_removexattr_args *ap)
        if (hfsmp->hfs_attribute_vp == NULL) {
                return (ENOATTR);
        }
-       btfile = VTOF(hfsmp->hfs_attribute_vp);
 
        MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               return (ENOMEM);
+       }
        bzero(iterator, sizeof(*iterator));
 
+       if ((result = hfs_lock(cp, HFS_EXCLUSIVE_LOCK))) {
+               return (result);
+       }
+
+       result = hfs_buildattrkey(cp->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
+       if (result) {
+               goto exit;      
+       }
+
        if (hfs_start_transaction(hfsmp) != 0) {
            result = EINVAL;
-           goto exit2;
+           goto exit;
        }
+       lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE | SFL_BITMAP, HFS_EXCLUSIVE_LOCK);
+       
+       result = remove_attribute_records(hfsmp, iterator);
 
-       result = buildkey(VTOC(vp)->c_fileid, ap->a_name, (HFSPlusAttrKey *)&iterator->key);
-       if (result)
-               goto exit2;     
+       hfs_systemfile_unlock(hfsmp, lockflags);
+
+       if (result == 0) {
+               cp->c_touch_chgtime = TRUE;
+
+               lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE, HFS_SHARED_LOCK);
+
+               /* If no more attributes exist, clear attribute bit */
+               result = file_attribute_exist(hfsmp, cp->c_fileid);
+               if (result == 0) {
+                       cp->c_attr.ca_recflags &= ~kHFSHasAttributesMask;
+               }
+               if (result == EEXIST) {
+                       result = 0;
+               }
+
+               hfs_systemfile_unlock(hfsmp, lockflags);
+
+               /* If ACL was removed, clear security bit */
+               if ((bcmp(ap->a_name, KAUTH_FILESEC_XATTR, sizeof(KAUTH_FILESEC_XATTR)) == 0)) {
+                       cp->c_attr.ca_recflags &= ~kHFSHasSecurityMask;
+               }
+               (void) hfs_update(vp, 0);
+       }
+
+       hfs_end_transaction(hfsmp);
+exit:
+       hfs_unlock(cp);
+       if (result == 0) {
+               HFS_KNOTE(vp, NOTE_ATTRIB);
+       }
+       FREE(iterator, M_TEMP);
+       return MacToVFSError(result);
+}
+
+/* Check if any attribute record exist for given fileID.  This function 
+ * is called by hfs_vnop_removexattr to determine if it should clear the 
+ * attribute bit in the catalog record or not.
+ * 
+ * Note - you must acquire a shared lock on the attribute btree before
+ *        calling this function.
+ * 
+ * Output: 
+ *     EEXIST  - If attribute record was found
+ *     0       - Attribute was not found
+ *     (other) - Other error (such as EIO) 
+ */
+int
+file_attribute_exist(struct hfsmount *hfsmp, uint32_t fileID)
+{
+       HFSPlusAttrKey *key;
+       struct BTreeIterator * iterator = NULL;
+       struct filefork *btfile;
+       int result = 0;
+
+       // if there's no attribute b-tree we sure as heck
+       // can't have any attributes!
+       if (hfsmp->hfs_attribute_vp == NULL) {
+           return false;
+       }
+
+       MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               result = ENOMEM;
+               goto out;
+       } 
+       bzero(iterator, sizeof(*iterator));
+       key = (HFSPlusAttrKey *)&iterator->key;
+
+       result = hfs_buildattrkey(fileID, NULL, key);
+       if (result) {
+               goto out;
+       }
+
+       btfile = VTOF(hfsmp->hfs_attribute_vp);
+       result = BTSearchRecord(btfile, iterator, NULL, NULL, NULL);
+       if (result && (result != btNotFound)) {
+               goto out;
+       }
+
+       result = BTIterateRecord(btfile, kBTreeNextRecord, iterator, NULL, NULL);
+       /* If no next record was found or fileID for next record did not match,
+        * no more attributes exist for this fileID
+        */
+       if ((result && (result == btNotFound)) || (key->fileID != fileID)) {
+               result = 0;     
+       } else {
+               result = EEXIST;
+       }
+
+out:
+       if (iterator) {
+               FREE(iterator, M_TEMP);
+       }
+       return result;
+}
+
+
+/*
+ * Remove all the records for a given attribute.
+ *
+ * - Used by hfs_vnop_removexattr, hfs_vnop_setxattr and hfs_removeallattr.
+ * - A transaction must have been started.
+ * - The Attribute b-tree file must be locked exclusive.
+ * - The Allocation Bitmap file must be locked exclusive.
+ * - The iterator key must be initialized.
+ */
+static int
+remove_attribute_records(struct hfsmount *hfsmp, BTreeIterator * iterator)
+{
+       struct filefork *btfile;
+       FSBufferDescriptor btdata;
+       HFSPlusAttrRecord attrdata;  /* 90 bytes */
+       u_int16_t datasize;
+       int result;
 
-       lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK);
+       btfile = VTOF(hfsmp->hfs_attribute_vp);
 
        btdata.bufferAddress = &attrdata;
        btdata.itemSize = sizeof(attrdata);
        btdata.itemCount = 1;
-       result = BTSearchRecord(btfile, iterator, &btdata, NULL, NULL);
-       if (result)
-               goto exit1;     
-
-       result = BTDeleteRecord(btfile, iterator);
-       (void) BTFlushPath(btfile);
-exit1:
-       hfs_systemfile_unlock(hfsmp, lockflags);
-       if (result == 0) {
-               VTOC(vp)->c_touch_chgtime = TRUE;
-               HFS_KNOTE(vp, NOTE_ATTRIB);
+       result = BTSearchRecord(btfile, iterator, &btdata, &datasize, NULL);
+       if (result) {
+               goto exit; /* no records. */
        }
-exit2:
-       if (result == btNotFound) {
-               result = ENOATTR;
+       /*
+        * Free the blocks from extent based attributes.
+        *
+        * Note that the block references (btree records) are removed
+        * before releasing the blocks in the allocation bitmap.
+        */
+       if (attrdata.recordType == kHFSPlusAttrForkData) {
+               int totalblks;
+               int extentblks;
+               u_int32_t *keystartblk;
+
+#if HFS_XATTR_VERBOSE
+               if (datasize < sizeof(HFSPlusAttrForkData)) {
+                       printf("remove_attribute_records: bad record size %d (expecting %d)\n", datasize, sizeof(HFSPlusAttrForkData));
+               }
+#endif
+               totalblks = attrdata.forkData.theFork.totalBlocks;
+
+               /* Process the first 8 extents. */
+               extentblks = count_extent_blocks(totalblks, attrdata.forkData.theFork.extents);
+               if (extentblks > totalblks)
+                       panic("remove_attribute_records: corruption...");
+               if (BTDeleteRecord(btfile, iterator) == 0) {
+                       free_attr_blks(hfsmp, extentblks, attrdata.forkData.theFork.extents);
+               }
+               totalblks -= extentblks;
+               keystartblk = &((HFSPlusAttrKey *)&iterator->key)->startBlock;
+
+               /* Process any overflow extents. */
+               while (totalblks) {
+                       *keystartblk += (u_int32_t)extentblks;
+
+                       result = BTSearchRecord(btfile, iterator, &btdata, &datasize, NULL);
+                       if (result ||
+                           (attrdata.recordType != kHFSPlusAttrExtents) ||
+                           (datasize < sizeof(HFSPlusAttrExtents))) {
+                               printf("remove_attribute_records: BTSearchRecord %d (%d), totalblks %d\n",
+                                       MacToVFSError(result), attrdata.recordType != kHFSPlusAttrExtents, totalblks);
+                               result = ENOATTR;
+                               break;   /* break from while */
+                       }
+                       /* Process the next 8 extents. */
+                       extentblks = count_extent_blocks(totalblks, attrdata.overflowExtents.extents);
+                       if (extentblks > totalblks)
+                               panic("remove_attribute_records: corruption...");
+                       if (BTDeleteRecord(btfile, iterator) == 0) {
+                               free_attr_blks(hfsmp, extentblks, attrdata.overflowExtents.extents);
+                       }
+                       totalblks -= extentblks;
+               }
+       } else {
+               result = BTDeleteRecord(btfile, iterator);
        }
-       hfs_end_transaction(hfsmp);
-
-       FREE(iterator, M_TEMP);
-
-       return MacToVFSError(result);
+       (void) BTFlushPath(btfile);
+exit:
+       return (result == btNotFound ? ENOATTR :  MacToVFSError(result));
 }
 
 
@@ -563,11 +1261,16 @@ hfs_vnop_listxattr(struct vnop_listxattr_args *ap)
 */
 {
        struct vnode *vp = ap->a_vp;
+       struct cnode *cp = VTOC(vp);
        struct hfsmount *hfsmp;
        uio_t uio = ap->a_uio;
        struct BTreeIterator * iterator = NULL;
        struct filefork *btfile;
        struct listattr_callback_state state;
+       void * finderinfo_start;
+       int finderinfo_size;
+       user_addr_t user_start = 0;
+       user_size_t user_len = 0;
        int lockflags;
        int result;
 
@@ -577,30 +1280,45 @@ hfs_vnop_listxattr(struct vnop_listxattr_args *ap)
        hfsmp = VTOHFS(vp);
        *ap->a_size = 0;
 
-       /* If Finder Info is non-empty then export it. */
-       if (bcmp(VTOC(vp)->c_finderinfo, emptyfinfo, sizeof(emptyfinfo)) != 0) {
+       if ((result = hfs_lock(cp, HFS_SHARED_LOCK))) {
+               return (result);
+       }
+
+       /* Don't expose a symlink's private type/creator. */
+       if (vnode_islnk(vp)) {
+               /* Skip over type/creator fields. */
+               finderinfo_start = &cp->c_finderinfo[8];
+               finderinfo_size = sizeof(cp->c_finderinfo) - 8;
+       } else {
+               finderinfo_start = &cp->c_finderinfo[0];
+               finderinfo_size = sizeof(cp->c_finderinfo);
+       }
+       /* If Finder Info is non-empty then export it's name. */
+       if (bcmp(finderinfo_start, emptyfinfo, finderinfo_size) != 0) {
                if (uio == NULL) {
                        *ap->a_size += sizeof(XATTR_FINDERINFO_NAME);
                } else if (uio_resid(uio) < sizeof(XATTR_FINDERINFO_NAME)) {
-                       return (ERANGE);
+                       result = ERANGE;
+                       goto exit;
                } else {
-                       result = uiomove((caddr_t)XATTR_FINDERINFO_NAME,
+                       result = uiomove(XATTR_FINDERINFO_NAME,
                                          sizeof(XATTR_FINDERINFO_NAME), uio);
                        if (result)
-                               return (result);
+                               goto exit;
                }
        }
-       /* If Resource Fork is non-empty then export it. */
-       if (vnode_isreg(vp) && RESOURCE_FORK_EXISTS(vp)) {
+       /* If Resource Fork is non-empty then export it's name. */
+       if (S_ISREG(cp->c_mode) && RSRC_FORK_EXISTS(cp)) {
                if (uio == NULL) {
                        *ap->a_size += sizeof(XATTR_RESOURCEFORK_NAME);
                } else if (uio_resid(uio) < sizeof(XATTR_RESOURCEFORK_NAME)) {
-                       return (ERANGE);
+                       result = ERANGE;
+                       goto exit;
                } else {
-                       result = uiomove((caddr_t)XATTR_RESOURCEFORK_NAME,
+                       result = uiomove(XATTR_RESOURCEFORK_NAME,
                                         sizeof(XATTR_RESOURCEFORK_NAME), uio);
                        if (result)
-                               return (result);
+                               goto exit;
                }
        }
        /*
@@ -608,21 +1326,40 @@ hfs_vnop_listxattr(struct vnop_listxattr_args *ap)
         * Return at this point.
         */
        if (hfsmp->hfs_flags & HFS_STANDARD) {
-               return (0);
+               result = 0;
+               goto exit;
        }
        /* Bail if we don't have any extended attributes. */
        if ((hfsmp->hfs_attribute_vp == NULL) ||
-           (VTOC(vp)->c_attr.ca_recflags & kHFSHasAttributesMask) == 0) {
-               return (0);
+           (cp->c_attr.ca_recflags & kHFSHasAttributesMask) == 0) {
+               result = 0;
+               goto exit;
        }
        btfile = VTOF(hfsmp->hfs_attribute_vp);
 
        MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               result = ENOMEM;
+               goto exit;
+       }
        bzero(iterator, sizeof(*iterator));
-       result = buildkey(VTOC(vp)->c_fileid, NULL, (HFSPlusAttrKey *)&iterator->key);
+       result = hfs_buildattrkey(cp->c_fileid, NULL, (HFSPlusAttrKey *)&iterator->key);
        if (result)
                goto exit;      
 
+       /*
+        * Lock the user's buffer here so that we won't fault on
+        * it in uiomove while holding the attributes b-tree lock.
+        */
+       if (uio && uio_isuserspace(uio)) {
+               user_start = uio_curriovbase(uio);
+               user_len = uio_curriovlen(uio);
+
+               if ((result = vslock(user_start, user_len)) != 0) {
+                       user_start = 0;
+                       goto exit;
+               }
+       }
        lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE, HFS_SHARED_LOCK);
 
        result = BTSearchRecord(btfile, iterator, NULL, NULL, NULL);
@@ -631,7 +1368,7 @@ hfs_vnop_listxattr(struct vnop_listxattr_args *ap)
                goto exit;
        }
 
-       state.fileID = VTOC(vp)->c_fileid;
+       state.fileID = cp->c_fileid;
        state.result = 0;
        state.uio = uio;
        state.size = 0;
@@ -645,12 +1382,18 @@ hfs_vnop_listxattr(struct vnop_listxattr_args *ap)
        if (uio == NULL) {
                *ap->a_size += state.size;
        }
-exit:
-       FREE(iterator, M_TEMP);
-       
+
        if (state.result || result == btNotFound)
                result = state.result;
 
+exit:
+       if (user_start) {
+               vsunlock(user_start, user_len, TRUE);
+       }
+       FREE(iterator, M_TEMP);
+
+       hfs_unlock(cp);
+       
        return MacToVFSError(result);
 }
 
@@ -676,8 +1419,9 @@ listattr_callback(const HFSPlusAttrKey *key, __unused const HFSPlusAttrData *dat
                return (1);     /* continue */
        }
 
+       /* Convert the attribute name into UTF-8. */
        result = utf8_encodestr(key->attrName, key->attrNameLen * sizeof(UniChar),
-                               attrname, &bytecount, sizeof(attrname), 0, 0);
+                               (u_int8_t *)attrname, &bytecount, sizeof(attrname), '/', 0);
        if (result) {
                state->result = result;
                return (0);     /* stop */
@@ -703,77 +1447,95 @@ listattr_callback(const HFSPlusAttrKey *key, __unused const HFSPlusAttrData *dat
        return (1); /* continue */
 }
 
-
 /*
  * Remove all the attributes from a cnode.
  *
- * A jornal transaction must be already started.
- * Attributes b-Tree must have exclusive lock held.
+ * This function creates/ends its own transaction so that each
+ * attribute is deleted in its own transaction (to avoid having
+ * a transaction grow too large).
+ *
+ * This function takes the necessary locks on the attribute
+ * b-tree file and the allocation (bitmap) file.
  */
 __private_extern__
 int
 hfs_removeallattr(struct hfsmount *hfsmp, u_int32_t fileid)
 {
-       BTreeIterator *next_iterator, *del_iterator;
-       HFSPlusAttrKey *next_key;
+       BTreeIterator *iterator;
+       HFSPlusAttrKey *key;
        struct filefork *btfile;
-       int result, iter_result;
+       int result, lockflags;
 
        if (hfsmp->hfs_attribute_vp == NULL) {
                return (0);
        }
        btfile = VTOF(hfsmp->hfs_attribute_vp);
 
-       MALLOC(next_iterator, BTreeIterator *, sizeof(BTreeIterator) * 2, M_TEMP, M_WAITOK);
-       bzero(next_iterator, sizeof(BTreeIterator) * 2);
-       del_iterator = &next_iterator[1];
-       next_key = (HFSPlusAttrKey *)&next_iterator->key;
-
-       /*
-        * Go to first possible attribute key/record pair
-        */
-       (void) buildkey(fileid, NULL, next_key);
-       result = BTIterateRecord(btfile, kBTreeNextRecord, next_iterator, NULL, NULL);
-       if (result || next_key->fileID != fileid) {
-               goto exit;
-       }
-       /* Remember iterator of attribute to delete */
-       bcopy(next_iterator, del_iterator, sizeof(BTreeIterator));
+       MALLOC(iterator, BTreeIterator *, sizeof(BTreeIterator), M_TEMP, M_WAITOK);
+       bzero(iterator, sizeof(BTreeIterator));
+       key = (HFSPlusAttrKey *)&iterator->key;
 
        /* Loop until there are no more attributes for this file id */
        for(;;) {
-               iter_result = BTIterateRecord(btfile, kBTreeNextRecord, next_iterator, NULL, NULL);
-
-               /* XXX need to free and extents for record types 0x20 and 0x30 */
-               result = BTDeleteRecord(btfile, del_iterator);
-               if (result) {
+               if (hfs_start_transaction(hfsmp) != 0) {
+                       result = EINVAL;
                        goto exit;
                }
-               if (iter_result) {
-                       result = iter_result;
-                       break;
+
+               /* Lock the attribute b-tree and the allocation (bitmap) files */
+               lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE | SFL_BITMAP, HFS_EXCLUSIVE_LOCK);
+
+               /*
+                * Go to first possible attribute key/record pair
+                */
+               (void) hfs_buildattrkey(fileid, NULL, key);
+               result = BTIterateRecord(btfile, kBTreeNextRecord, iterator, NULL, NULL);
+               if (result || key->fileID != fileid) {
+                       hfs_systemfile_unlock(hfsmp, lockflags);
+                       hfs_end_transaction(hfsmp);
+                       goto exit;
                }
-               if (iter_result || next_key->fileID != fileid) {
-                       break;  /* end of attributes for this file id */
+               result = remove_attribute_records(hfsmp, iterator);
+
+#if HFS_XATTR_VERBOSE
+               if (result) {
+                       printf("hfs_removeallattr: unexpected err %d\n", result);
                }
-               bcopy(next_iterator, del_iterator, sizeof(BTreeIterator));
+#endif
+               hfs_systemfile_unlock(hfsmp, lockflags);
+               hfs_end_transaction(hfsmp);
        }
 exit:
-       (void) BTFlushPath(btfile);
+       FREE(iterator, M_TEMP);
+       return (result == btNotFound ? 0: MacToVFSError(result));
+}
 
-       if (result == btNotFound) {
-               result = 0;
+__private_extern__
+void
+hfs_xattr_init(struct hfsmount * hfsmp)
+{
+       /*
+        * If there isn't an attributes b-tree then create one.
+        */
+       if (!(hfsmp->hfs_flags & HFS_STANDARD) &&
+           (hfsmp->hfs_attribute_vp == NULL) &&
+           !(hfsmp->hfs_flags & HFS_READ_ONLY)) {
+               (void) hfs_create_attr_btree(hfsmp, ATTRIBUTE_FILE_NODE_SIZE,
+                                            getnodecount(hfsmp, ATTRIBUTE_FILE_NODE_SIZE));
        }
-       FREE(next_iterator, M_TEMP);
-       return (result);
+       if (hfsmp->hfs_attribute_vp)
+               hfsmp->hfs_max_inline_attrsize = getmaxinlineattrsize(hfsmp->hfs_attribute_vp);
 }
 
 /*
- * Enable/Disable extended security (ACLs).
+ * Enable/Disable volume attributes stored as EA for root file system.
+ * Supported attributes are - 
+ *     1. ACLs
+ *     2. Extent-based Extended Attributes 
  */
 __private_extern__
 int
-hfs_setextendedsecurity(struct hfsmount *hfsmp, int state)
+hfs_set_volxattr(struct hfsmount *hfsmp, unsigned int xattrtype, int state)
 {
        struct BTreeIterator * iterator = NULL;
        struct filefork *btfile;
@@ -784,32 +1546,44 @@ hfs_setextendedsecurity(struct hfsmount *hfsmp, int state)
                return (ENOTSUP);
        }
 
+       /*
+        * If there isn't an attributes b-tree then create one.
+        */
+       if (hfsmp->hfs_attribute_vp == NULL) {
+               result = hfs_create_attr_btree(hfsmp, ATTRIBUTE_FILE_NODE_SIZE,
+                                              getnodecount(hfsmp, ATTRIBUTE_FILE_NODE_SIZE));
+               if (result) {
+                       return (result);
+               }
+       }
+
        MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               return (ENOMEM);
+       } 
        bzero(iterator, sizeof(*iterator));
 
        /*
         * Build a b-tree key.
         * We use the root's parent id (1) to hold this volume attribute.
         */
-       (void) buildkey(kHFSRootParentID, XATTR_EXTENDEDSECURITY_NAME,
-                         (HFSPlusAttrKey *)&iterator->key);
+       if (xattrtype == HFS_SETACLSTATE) {
+               /* ACL */
+               (void) hfs_buildattrkey(kHFSRootParentID, XATTR_EXTENDEDSECURITY_NAME,
+                                     (HFSPlusAttrKey *)&iterator->key);
+       } else if (xattrtype == HFS_SET_XATTREXTENTS_STATE) {
+               /* Extent-based extended attributes */
+               (void) hfs_buildattrkey(kHFSRootParentID, XATTR_XATTREXTENTS_NAME,
+                                     (HFSPlusAttrKey *)&iterator->key);
+       } else {
+               result = EINVAL;
+               goto exit;
+       }
 
        /* Start a transaction for our changes. */
        if (hfs_start_transaction(hfsmp) != 0) {
                result = EINVAL;
-               goto exit2;
-       }
-       /*
-        * If there isn't an attributes b-tree then create one.
-        */
-       if (hfsmp->hfs_attribute_vp == NULL) {
-               lockflags = hfs_systemfile_lock(hfsmp, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK);
-               result = hfs_create_attr_btree(hfsmp, ATTRIBUTE_FILE_NODE_SIZE,
-                                              getnodecount(hfsmp, ATTRIBUTE_FILE_NODE_SIZE));
-               hfs_systemfile_unlock(hfsmp, lockflags);
-               if (result) {
-                       goto exit1;
-               }
+               goto exit;
        }
        btfile = VTOF(hfsmp->hfs_attribute_vp);
 
@@ -823,7 +1597,7 @@ hfs_setextendedsecurity(struct hfsmount *hfsmp, int state)
        } else {
                FSBufferDescriptor btdata;
                HFSPlusAttrData attrdata;
-               UInt16 datasize;
+               u_int16_t datasize;
 
                datasize = sizeof(attrdata);
                btdata.bufferAddress = &attrdata;
@@ -844,30 +1618,45 @@ hfs_setextendedsecurity(struct hfsmount *hfsmp, int state)
        (void) BTFlushPath(btfile);
 
        hfs_systemfile_unlock(hfsmp, lockflags);
-exit1:
+
        /* Finish the transaction of our changes. */
        hfs_end_transaction(hfsmp);
-exit2:
-       FREE(iterator, M_TEMP);
-
+exit:
+       if (iterator) {
+               FREE(iterator, M_TEMP);
+       }
        if (result == 0) {
-               if (state == 0)
-                       vfs_clearextendedsecurity(HFSTOVFS(hfsmp));
-               else
-                       vfs_setextendedsecurity(HFSTOVFS(hfsmp));
-               printf("hfs: %s extended security on %s\n",
-                      state == 0 ? "disabling" : "enabling", hfsmp->vcbVN);
+               if (xattrtype == HFS_SETACLSTATE) {
+                       if (state == 0) {
+                               vfs_clearextendedsecurity(HFSTOVFS(hfsmp));
+                       } else {
+                               vfs_setextendedsecurity(HFSTOVFS(hfsmp));
+                       }
+               } else { 
+                       /* HFS_SET_XATTREXTENTS_STATE */
+                       HFS_MOUNT_LOCK(hfsmp, TRUE);
+                       if (state == 0) {
+                               hfsmp->hfs_flags &= ~HFS_XATTR_EXTENTS; 
+                       } else {
+                               hfsmp->hfs_flags |= HFS_XATTR_EXTENTS; 
+                       }
+                       HFS_MOUNT_UNLOCK(hfsmp, TRUE); 
+               }
        }
 
        return MacToVFSError(result);
 }
 
-/*
- * Check for extended security (ACLs).
+
+ /*
+ * Check for volume attributes stored as EA for root file system.
+ * Supported attributes are - 
+ *     1. ACLs
+ *     2. Extent-based Extended Attributes 
  */
 __private_extern__
 void
-hfs_checkextendedsecurity(struct hfsmount *hfsmp)
+hfs_check_volxattr(struct hfsmount *hfsmp, unsigned int xattrtype)
 {
        struct BTreeIterator * iterator;
        struct filefork *btfile;
@@ -880,15 +1669,24 @@ hfs_checkextendedsecurity(struct hfsmount *hfsmp)
        }
 
        MALLOC(iterator, BTreeIterator *, sizeof(*iterator), M_TEMP, M_WAITOK);
+       if (iterator == NULL) {
+               return;
+       }
        bzero(iterator, sizeof(*iterator));
 
        /*
         * Build a b-tree key.
         * We use the root's parent id (1) to hold this volume attribute.
         */
-       (void) buildkey(kHFSRootParentID, XATTR_EXTENDEDSECURITY_NAME,
-                         (HFSPlusAttrKey *)&iterator->key);
-
+       if (xattrtype == HFS_SETACLSTATE) {
+               /* ACLs */
+               (void) hfs_buildattrkey(kHFSRootParentID, XATTR_EXTENDEDSECURITY_NAME,
+                                     (HFSPlusAttrKey *)&iterator->key);
+       } else {
+               /* Extent-based extended attributes */
+               (void) hfs_buildattrkey(kHFSRootParentID, XATTR_XATTREXTENTS_NAME,
+                                     (HFSPlusAttrKey *)&iterator->key);
+       }
        btfile = VTOF(hfsmp->hfs_attribute_vp);
 
        lockflags = hfs_systemfile_lock(hfsmp, SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK);
@@ -900,8 +1698,13 @@ hfs_checkextendedsecurity(struct hfsmount *hfsmp)
        FREE(iterator, M_TEMP);
 
        if (result == 0) {
-               vfs_setextendedsecurity(HFSTOVFS(hfsmp));
-               printf("hfs mount: enabling extended security on %s\n", hfsmp->vcbVN);
+               if (xattrtype == HFS_SETACLSTATE) {
+                       vfs_setextendedsecurity(HFSTOVFS(hfsmp));
+               } else {
+                       HFS_MOUNT_LOCK(hfsmp, TRUE);
+                       hfsmp->hfs_flags |= HFS_XATTR_EXTENTS; 
+                       HFS_MOUNT_UNLOCK(hfsmp, TRUE); 
+               }
        }
 }
 
@@ -974,10 +1777,11 @@ hfs_attrkeycompare(HFSPlusAttrKey *searchKey, HFSPlusAttrKey *trialKey)
 
 
 /*
- * buildkey - build an Attribute b-tree key
+ * hfs_buildattrkey - build an Attribute b-tree key
  */
-static int
-buildkey(u_int32_t fileID, const char *attrname, HFSPlusAttrKey *key)
+__private_extern__
+int
+hfs_buildattrkey(u_int32_t fileID, const char *attrname, HFSPlusAttrKey *key)
 {
        int result = 0;
        size_t unicodeBytes = 0;
@@ -986,7 +1790,7 @@ buildkey(u_int32_t fileID, const char *attrname, HFSPlusAttrKey *key)
                /*
                 * Convert filename from UTF-8 into Unicode
                 */     
-               result = utf8_decodestr(attrname, strlen(attrname), key->attrName,
+               result = utf8_decodestr((const u_int8_t *)attrname, strlen(attrname), key->attrName,
                                        &unicodeBytes, sizeof(key->attrName), 0, 0);
                if (result) {
                        if (result != ENAMETOOLONG)
@@ -1012,22 +1816,24 @@ buildkey(u_int32_t fileID, const char *attrname, HFSPlusAttrKey *key)
 static int
 getnodecount(struct hfsmount *hfsmp, size_t nodesize)
 {
-       int avedatasize;
-       int recpernode;
-       int count;
+       u_int64_t freebytes;
+       u_int64_t calcbytes;
 
-       avedatasize = sizeof(u_int16_t);  /* index slot */
-       avedatasize += kHFSPlusAttrKeyMinimumLength + HFS_AVERAGE_NAME_SIZE * sizeof(u_int16_t);
-       avedatasize += sizeof(HFSPlusAttrData) + 32;
-
-       recpernode = (nodesize - sizeof(BTNodeDescriptor)) / avedatasize;
+       /*
+        * 10.4: Scale base on current catalog file size (20 %) up to 20 MB.
+        * 10.5: Attempt to be as big as the catalog clump size.
+        *
+        * Use no more than 10 % of the remaining free space.
+        */
+       freebytes = (u_int64_t)hfs_freeblks(hfsmp, 0) * (u_int64_t)hfsmp->blockSize;
 
-       count = (hfsmp->hfs_filecount + hfsmp->hfs_dircount) / 8;
-       count /= recpernode;
+       calcbytes = MIN(hfsmp->hfs_catalog_cp->c_datafork->ff_size / 5, 20 * 1024 * 1024);
 
-       /* XXX should also consider volume size XXX */
+       calcbytes = MAX(calcbytes, hfsmp->hfs_catalog_cp->c_datafork->ff_clumpsize);
+       
+       calcbytes = MIN(calcbytes, freebytes / 10);
 
-       return (MAX(count, (int)(1024 * 1024) / (int)nodesize));
+       return (MAX(2, (int)(calcbytes / nodesize)));
 }
 
 
@@ -1051,7 +1857,7 @@ getmaxinlineattrsize(struct vnode * attrvp)
        }
        maxsize = nodesize;
        maxsize -= sizeof(BTNodeDescriptor);     /* minus node descriptor */
-       maxsize -= 3 * sizeof(UInt16);           /* minus 3 index slots */
+       maxsize -= 3 * sizeof(u_int16_t);        /* minus 3 index slots */
        maxsize /= 2;                            /* 2 key/rec pairs minumum */
        maxsize -= sizeof(HFSPlusAttrKey);       /* minus maximum key size */
        maxsize -= sizeof(HFSPlusAttrData) - 2;  /* minus data header */
@@ -1060,4 +1866,334 @@ getmaxinlineattrsize(struct vnode * attrvp)
        return (maxsize);
 }
 
+/*
+ * Get a referenced vnode for attribute data I/O.
+ */
+static int
+get_attr_data_vnode(struct hfsmount *hfsmp, vnode_t *vpp)
+{
+       vnode_t vp;
+       int result = 0;
+
+       vp = hfsmp->hfs_attrdata_vp;
+       if (vp == NULLVP) {
+               struct cat_desc cat_desc;
+               struct cat_attr cat_attr;
+               struct cat_fork cat_fork;
+
+               /* We don't tag it as a system file since we intend to use cluster I/O. */
+               bzero(&cat_desc, sizeof(cat_desc));
+               cat_desc.cd_parentcnid = kHFSRootParentID;
+               cat_desc.cd_nameptr = (const u_int8_t *)hfs_attrdatafilename;
+               cat_desc.cd_namelen = strlen(hfs_attrdatafilename);
+               cat_desc.cd_cnid = kHFSAttributeDataFileID;
+
+               bzero(&cat_attr, sizeof(cat_attr));
+               cat_attr.ca_linkcount = 1;
+               cat_attr.ca_mode = S_IFREG;
+               cat_attr.ca_fileid = cat_desc.cd_cnid;
+               cat_attr.ca_blocks = hfsmp->totalBlocks;
+
+               /*
+                * The attribute data file is a virtual file that spans the
+                * entire file system space.
+                *
+                * Each extent-based attribute occupies a unique portion of
+                * in this virtual file.  The cluster I/O is done using actual
+                * allocation block offsets so no additional mapping is needed
+                * for the VNOP_BLOCKMAP call.
+                *
+                * This approach allows the attribute data to be cached without
+                * incurring the high cost of using a separate vnode per attribute.
+                *
+                * Since we need to acquire the attribute b-tree file lock anyways,
+                * the virtual file doesn't introduce any additional serialization.
+                */
+               bzero(&cat_fork, sizeof(cat_fork));
+               cat_fork.cf_size = (u_int64_t)hfsmp->totalBlocks * (u_int64_t)hfsmp->blockSize;
+               cat_fork.cf_blocks = hfsmp->totalBlocks;
+               cat_fork.cf_extents[0].startBlock = 0;
+               cat_fork.cf_extents[0].blockCount = cat_fork.cf_blocks;
+       
+               result = hfs_getnewvnode(hfsmp, NULL, NULL, &cat_desc, 0, &cat_attr, &cat_fork, &vp);
+               if (result == 0) {
+                       HFS_MOUNT_LOCK(hfsmp, 1);
+                       /* Check if someone raced us for creating this vnode. */
+                       if (hfsmp->hfs_attrdata_vp != NULLVP) {
+                               HFS_MOUNT_UNLOCK(hfsmp, 1);
+                               vnode_put(vp);
+                               vnode_recycle(vp);
+                               vp = hfsmp->hfs_attrdata_vp;
+                       } else {
+                               hfsmp->hfs_attrdata_vp = vp;
+                               HFS_MOUNT_UNLOCK(hfsmp, 1);
+                               /* Keep a reference on this vnode until unmount */
+                               vnode_ref_ext(vp, O_EVTONLY);
+                               hfs_unlock(VTOC(vp));
+                       }
+               }
+       } else {
+               if ((result = vnode_get(vp)))
+                       vp = NULLVP;
+       }
+       *vpp = vp;
+       return (result);
+}
+
+/*
+ * Read an extent based attribute.
+ */
+static int
+read_attr_data(struct hfsmount *hfsmp, uio_t uio, size_t datasize, HFSPlusExtentDescriptor *extents)
+{
+       vnode_t evp = NULLVP;
+       int bufsize;
+       int iosize;
+       int attrsize;
+       int blksize;
+       int i;
+       int result = 0;
+
+       if ((result = get_attr_data_vnode(hfsmp, &evp))) {
+               return (result);
+       }
+       hfs_lock_truncate(VTOC(evp), 0);
+
+       bufsize = (int)uio_resid(uio);
+       attrsize = (int)datasize;
+       blksize = (int)hfsmp->blockSize;
+
+       /*
+        * Read the attribute data one extent at a time.
+        * For the typical case there is only one extent.
+        */
+       for (i = 0; (attrsize > 0) && (bufsize > 0) && (extents[i].startBlock != 0); ++i) {
+               iosize = (int)extents[i].blockCount * blksize;
+               iosize = MIN(iosize, attrsize);
+               iosize = MIN(iosize, bufsize);
+               uio_setresid(uio, iosize);
+               uio_setoffset(uio, (u_int64_t)extents[i].startBlock * (u_int64_t)blksize);
+
+               result = cluster_read(evp, uio, VTOF(evp)->ff_size, IO_SYNC | IO_UNIT);
+
+#if HFS_XATTR_VERBOSE
+               printf("read_attr_data: cr iosize %d [%d, %d] (%d)\n",
+                       iosize, extents[i].startBlock, extents[i].blockCount, result);
+#endif
+               if (result)
+                       break;
+               attrsize -= iosize;
+               bufsize -= iosize;
+       }
+       uio_setresid(uio, bufsize);
+       uio_setoffset(uio, datasize);
+
+       hfs_unlock_truncate(VTOC(evp), 0);
+       vnode_put(evp);
+       return (result);
+}
+
+/*
+ * Write an extent based attribute.
+ */
+static int
+write_attr_data(struct hfsmount *hfsmp, uio_t uio, size_t datasize, HFSPlusExtentDescriptor *extents)
+{
+       vnode_t evp = NULLVP;
+       off_t filesize;
+       int bufsize;
+       int attrsize;
+       int iosize;
+       int blksize;
+       int i;
+       int result = 0;
+
+       /* Get exclusive use of attribute data vnode. */
+       if ((result = get_attr_data_vnode(hfsmp, &evp))) {
+               return (result);
+       }
+       hfs_lock_truncate(VTOC(evp), 0);
+
+       bufsize = uio_resid(uio);
+       attrsize = (int) datasize;
+       blksize = (int) hfsmp->blockSize;
+       filesize = VTOF(evp)->ff_size;
+
+       /*
+        * Write the attribute data one extent at a time.
+        */
+       for (i = 0; (attrsize > 0) && (bufsize > 0) && (extents[i].startBlock != 0); ++i) {
+               iosize = (int)extents[i].blockCount * blksize;
+               iosize = MIN(iosize, attrsize);
+               iosize = MIN(iosize, bufsize);
+               uio_setresid(uio, iosize);
+               uio_setoffset(uio, (u_int64_t)extents[i].startBlock * (u_int64_t)blksize);
+
+               result = cluster_write(evp, uio, filesize, filesize, filesize,
+                                      (off_t) 0, IO_SYNC | IO_UNIT);
+#if HFS_XATTR_VERBOSE
+               printf("write_attr_data: cw iosize %d [%d, %d] (%d)\n",
+                       iosize, extents[i].startBlock, extents[i].blockCount, result);
+#endif
+               if (result)
+                       break;
+               attrsize -= iosize;
+               bufsize -= iosize;
+       }
+       uio_setresid(uio, bufsize);
+       uio_setoffset(uio, datasize);
+
+       hfs_unlock_truncate(VTOC(evp), 0);
+       vnode_put(evp);
+       return (result);
+}
+
+/*
+ * Allocate blocks for an extent based attribute.
+ */
+static int
+alloc_attr_blks(struct hfsmount *hfsmp, size_t attrsize, size_t extentbufsize, HFSPlusExtentDescriptor *extents, int *blocks)
+{
+       int blkcnt;
+       int startblk;
+       int lockflags;
+       int i;
+       int maxextents;
+       int result = 0;
+
+       startblk = hfsmp->hfs_metazone_end;
+       blkcnt = howmany(attrsize, hfsmp->blockSize);
+       if (blkcnt > (int)hfs_freeblks(hfsmp, 0)) {
+               return (ENOSPC);
+       }
+       *blocks = blkcnt;
+       maxextents = extentbufsize / sizeof(HFSPlusExtentDescriptor);
+
+       lockflags = hfs_systemfile_lock(hfsmp, SFL_BITMAP, HFS_EXCLUSIVE_LOCK);
+
+       for (i = 0; (blkcnt > 0) && (i < maxextents); i++) {
+               result = BlockAllocate(hfsmp, startblk, blkcnt, blkcnt, 0, 0,
+                                      &extents[i].startBlock, &extents[i].blockCount);
+#if HFS_XATTR_VERBOSE
+               printf("alloc_attr_blks: BA blkcnt %d [%d, %d] (%d)\n",
+                       blkcnt, extents[i].startBlock, extents[i].blockCount, result);
+#endif
+               if (result) {
+                       extents[i].startBlock = 0;
+                       extents[i].blockCount = 0;
+                       break;
+               }
+               blkcnt -= extents[i].blockCount;
+               startblk = extents[i].startBlock + extents[i].blockCount;
+       }
+       /*
+        * If it didn't fit in the extents buffer then bail.
+        */
+       if (blkcnt) {
+               result = ENOSPC;
+
+#if HFS_XATTR_VERBOSE
+               printf("alloc_attr_blks: unexpected failure, %d blocks unallocated\n", blkcnt);
+#endif
+               for (; i <= 0; i--) {
+                       if ((blkcnt = extents[i].blockCount) != 0) {
+                               (void) BlockDeallocate(hfsmp, extents[i].startBlock, blkcnt);
+                               extents[i].startBlock = 0;
+                               extents[i].blockCount = 0;
+                   }
+               }
+       }
+
+       hfs_systemfile_unlock(hfsmp, lockflags);
+       return MacToVFSError(result);
+}
+
+/*
+ * Release blocks from an extent based attribute.
+ */
+static void
+free_attr_blks(struct hfsmount *hfsmp, int blkcnt, HFSPlusExtentDescriptor *extents)
+{
+       vnode_t evp = NULLVP;
+       int remblks = blkcnt;
+       int lockflags;
+       int i;
+
+       if (get_attr_data_vnode(hfsmp, &evp) != 0) {
+               evp = NULLVP;
+       }
+       lockflags = hfs_systemfile_lock(hfsmp, SFL_BITMAP, HFS_EXCLUSIVE_LOCK);
+
+       for (i = 0; (remblks > 0) && (extents[i].blockCount != 0); i++) {
+               if (extents[i].blockCount > (u_int32_t)blkcnt) {
+#if HFS_XATTR_VERBOSE
+                       printf("free_attr_blks: skipping bad extent [%d, %d]\n",
+                               extents[i].startBlock, extents[i].blockCount);
+#endif
+                       extents[i].blockCount = 0;
+                       continue;
+               }
+               if (extents[i].startBlock == 0) {
+                       break;
+               }
+               (void)BlockDeallocate(hfsmp, extents[i].startBlock, extents[i].blockCount);
+               extents[i].startBlock = 0;
+               extents[i].blockCount = 0;
+               remblks -= extents[i].blockCount;
+
+#if HFS_XATTR_VERBOSE
+               printf("free_attr_blks: BlockDeallocate [%d, %d]\n",
+                      extents[i].startBlock, extents[i].blockCount);
+#endif
+               /* Discard any resident pages for this block range. */
+               if (evp) {
+                       off_t  start, end;
+
+                       start = (u_int64_t)extents[i].startBlock * (u_int64_t)hfsmp->blockSize;
+                       end = start + (u_int64_t)extents[i].blockCount * (u_int64_t)hfsmp->blockSize;
+                       (void) ubc_msync(hfsmp->hfs_attrdata_vp, start, end, &start, UBC_INVALIDATE);
+               }
+       }
+
+       hfs_systemfile_unlock(hfsmp, lockflags);
+       if (evp) {
+               vnode_put(evp);
+       }
+}
+
+static int
+has_overflow_extents(HFSPlusForkData *forkdata)
+{
+       u_int32_t blocks;
+
+       if (forkdata->extents[7].blockCount == 0)
+               return (0);
+
+       blocks = forkdata->extents[0].blockCount +
+                forkdata->extents[1].blockCount +
+                forkdata->extents[2].blockCount +
+                forkdata->extents[3].blockCount +
+                forkdata->extents[4].blockCount +
+                forkdata->extents[5].blockCount +
+                forkdata->extents[6].blockCount +
+                forkdata->extents[7].blockCount;       
+
+       return (forkdata->totalBlocks > blocks);
+}
 
+static int
+count_extent_blocks(int maxblks, HFSPlusExtentRecord extents)
+{
+       int blocks;
+       int i;
+
+       for (i = 0, blocks = 0; i < kHFSPlusExtentDensity; ++i) {
+               /* Ignore obvious bogus extents. */
+               if (extents[i].blockCount > (u_int32_t)maxblks)
+                       continue;
+               if (extents[i].startBlock == 0 || extents[i].blockCount == 0)
+                       break;
+               blocks += extents[i].blockCount;
+       }
+       return (blocks);
+}