1 files changed, 19 insertions, 1 deletions

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index c68baeb0974a..d0ab78837057 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2383,6 +2383,8 @@ xfs_bmap_btalloc(
         int             tryagain;
         int             error;
 
+        ASSERT(ap->length);
+
         mp = ap->ip->i_mount;
         align = ap->userdata ? xfs_get_extsz_hint(ap->ip) : 0;
         if (unlikely(align)) {
@@ -4629,6 +4631,8 @@ xfs_bmapi_allocate(
         int                     error;
         int                     rt;
 
+        ASSERT(bma->length > 0);
+
         rt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(bma->ip);
 
         /*
@@ -4849,6 +4853,7 @@ xfs_bmapi_write(
         ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
         ASSERT(!(flags & XFS_BMAPI_IGSTATE));
         ASSERT(tp != NULL);
+        ASSERT(len > 0);
 
         whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
                 XFS_ATTR_FORK : XFS_DATA_FORK;
@@ -4918,9 +4923,22 @@ xfs_bmapi_write(
                         bma.eof = eof;
                         bma.conv = !!(flags & XFS_BMAPI_CONVERT);
                         bma.wasdel = wasdelay;
-                        bma.length = len;
                         bma.offset = bno;
 
+                        /*
+                         * There's a 32/64 bit type mismatch between the
+                         * allocation length request (which can be 64 bits in
+                         * length) and the bma length request, which is
+                         * xfs_extlen_t and therefore 32 bits. Hence we have to
+                         * check for 32-bit overflows and handle them here.
+                         */
+                        if (len > (xfs_filblks_t)MAXEXTLEN)
+                                bma.length = MAXEXTLEN;
+                        else
+                                bma.length = len;
+
+                        ASSERT(len > 0);
+                        ASSERT(bma.length > 0);
                         error = xfs_bmapi_allocate(&bma, flags);
                         if (error)
                                 goto error0;