6 files changed, 27 insertions, 9 deletions

diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 3b9e626f7cd1..03aa908a9cb9 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -1301,7 +1301,8 @@ xfs_file_ioctl(
         case XFS_IOC_ALLOCSP64:
         case XFS_IOC_FREESP64:
         case XFS_IOC_RESVSP64:
-        case XFS_IOC_UNRESVSP64: {
+        case XFS_IOC_UNRESVSP64:
+        case XFS_IOC_ZERO_RANGE: {
                 xfs_flock64_t           bf;
 
                 if (copy_from_user(&bf, arg, sizeof(bf)))
diff --git a/fs/xfs/linux-2.6/xfs_ioctl32.c b/fs/xfs/linux-2.6/xfs_ioctl32.c
index 6c83f7f62dc9..464bcc76e980 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl32.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl32.c
@@ -574,6 +574,7 @@ xfs_file_compat_ioctl(
         case XFS_IOC_FSGEOMETRY_V1:
         case XFS_IOC_FSGROWFSDATA:
         case XFS_IOC_FSGROWFSRT:
+        case XFS_IOC_ZERO_RANGE:
                 return xfs_file_ioctl(filp, cmd, p);
 #else
         case XFS_IOC_ALLOCSP_32:
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index f90dadd5a968..5e33b7862d41 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -4744,8 +4744,12 @@ xfs_bmapi(
                  * Check if writing previously allocated but
                  * unwritten extents.
                  */
-                if (wr && mval->br_state == XFS_EXT_UNWRITTEN &&
-                    ((flags & (XFS_BMAPI_PREALLOC|XFS_BMAPI_DELAY)) == 0)) {
+                if (wr &&
+                    ((mval->br_state == XFS_EXT_UNWRITTEN &&
+                      ((flags & (XFS_BMAPI_PREALLOC|XFS_BMAPI_DELAY)) == 0)) ||
+                     (mval->br_state == XFS_EXT_NORM &&
+                      ((flags & (XFS_BMAPI_PREALLOC|XFS_BMAPI_CONVERT)) ==
+                                (XFS_BMAPI_PREALLOC|XFS_BMAPI_CONVERT))))) {
                         /*
                          * Modify (by adding) the state flag, if writing.
                          */
@@ -4757,7 +4761,9 @@ xfs_bmapi(
                                         *firstblock;
                                 cur->bc_private.b.flist = flist;
                         }
-                        mval->br_state = XFS_EXT_NORM;
+                        mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
+                                                ? XFS_EXT_NORM
+                                                : XFS_EXT_UNWRITTEN;
                         error = xfs_bmap_add_extent(ip, lastx, &cur, mval,
                                 firstblock, flist, &tmp_logflags,
                                 whichfork, (flags & XFS_BMAPI_RSVBLOCKS));
diff --git a/fs/xfs/xfs_bmap.h b/fs/xfs/xfs_bmap.h
index b13569a6179b..71ec9b6ecdfc 100644
--- a/fs/xfs/xfs_bmap.h
+++ b/fs/xfs/xfs_bmap.h
@@ -74,9 +74,12 @@ typedef	struct xfs_bmap_free
 #define XFS_BMAPI_IGSTATE       0x080   /* Ignore state - */
                                         /* combine contig. space */
 #define XFS_BMAPI_CONTIG        0x100   /* must allocate only one extent */
-#define XFS_BMAPI_CONVERT       0x200   /* unwritten extent conversion - */
-                                        /* need write cache flushing and no */
-                                        /* additional allocation alignments */
+/*
+ * unwritten extent conversion - this needs write cache flushing and no additional
+ * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
+ * from written to unwritten, otherwise convert from unwritten to written.
+ */
+#define XFS_BMAPI_CONVERT       0x200
 
 #define XFS_BMAPI_FLAGS \
         { XFS_BMAPI_WRITE,      "WRITE" }, \
diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index 87c2e9d02288..10f6093671b0 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -448,6 +448,7 @@ typedef struct xfs_handle {
 /*      XFS_IOC_SETBIOSIZE ---- deprecated 46      */
 /*      XFS_IOC_GETBIOSIZE ---- deprecated 47      */
 #define XFS_IOC_GETBMAPX        _IOWR('X', 56, struct getbmap)
+#define XFS_IOC_ZERO_RANGE      _IOW ('X', 57, struct xfs_flock64)
 
 /*
  * ioctl commands that replace IRIX syssgi()'s
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 4c7c7bfb2b2f..dc6e4fb8bbc9 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -2272,7 +2272,7 @@ xfs_alloc_file_space(
         count = len;
         imapp = &imaps[0];
         nimaps = 1;
-        bmapi_flag = XFS_BMAPI_WRITE | (alloc_type ? XFS_BMAPI_PREALLOC : 0);
+        bmapi_flag = XFS_BMAPI_WRITE | alloc_type;
         startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
         allocatesize_fsb = XFS_B_TO_FSB(mp, count);
 
@@ -2711,6 +2711,7 @@ xfs_change_file_space(
         xfs_off_t       llen;
         xfs_trans_t     *tp;
         struct iattr    iattr;
+        int             prealloc_type;
 
         if (!S_ISREG(ip->i_d.di_mode))
                 return XFS_ERROR(EINVAL);
@@ -2753,12 +2754,17 @@ xfs_change_file_space(
          * size to be changed.
          */
         setprealloc = clrprealloc = 0;
+        prealloc_type = XFS_BMAPI_PREALLOC;
 
         switch (cmd) {
+        case XFS_IOC_ZERO_RANGE:
+                prealloc_type |= XFS_BMAPI_CONVERT;
+                xfs_tosspages(ip, startoffset, startoffset + bf->l_len, 0);
+                /* FALLTHRU */
         case XFS_IOC_RESVSP:
         case XFS_IOC_RESVSP64:
                 error = xfs_alloc_file_space(ip, startoffset, bf->l_len,
-                                                                1, attr_flags);
+                                                prealloc_type, attr_flags);
                 if (error)
                         return error;
                 setprealloc = 1;