vfs_ceph: remove ceph_fallocate/ceph_ftruncate fallback

Both libcephfs functions are supported and capable of extending files,
so fallback can be dropped.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13807

Signed-off-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
(cherry picked from commit 155f1289ba7a4802fbb99fbc9ea90d8bc6cff0c9)
[ddiss@samba.org: rebase atop 48t without 532ff3a5b958]

Autobuild-User(v4-8-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-8-test): Tue Mar  5 13:01:15 UTC 2019 on sn-devel-144

1 files changed, 8 insertions, 94 deletions

diff --git a/source3/modules/vfs_ceph.c b/source3/modules/vfs_ceph.c
index c68a98f97e8..5d67142997d 100644
--- a/source3/modules/vfs_ceph.c
+++ b/source3/modules/vfs_ceph.c
@@ -1124,9 +1124,7 @@ static struct smb_filename *cephwrap_getwd(struct vfs_handle_struct *handle,
 static int strict_allocate_ftruncate(struct vfs_handle_struct *handle, files_struct *fsp, off_t len)
 {
 	off_t space_to_write;
-	uint64_t space_avail;
-	uint64_t bsize,dfree,dsize;
-	int ret;
+	int result;
 	NTSTATUS status;
 	SMB_STRUCT_STAT *pst;
 
@@ -1146,112 +1144,28 @@ static int strict_allocate_ftruncate(struct vfs_handle_struct *handle, files_str
 
 	/* Shrink - just ftruncate. */
 	if (pst->st_ex_size > len) {
-		ret = ceph_ftruncate(handle->data, fsp->fh->fd, len);
-		WRAP_RETURN(ret);
+		result = ceph_ftruncate(handle->data, fsp->fh->fd, len);
+		WRAP_RETURN(result);
 	}
 
 	space_to_write = len - pst->st_ex_size;
-
-	/* for allocation try fallocate first. This can fail on some
-	   platforms e.g. when the filesystem doesn't support it and no
-	   emulation is being done by the libc (like on AIX with JFS1). In that
-	   case we do our own emulation. fallocate implementations can
-	   return ENOTSUP or EINVAL in cases like that. */
-	ret = SMB_VFS_FALLOCATE(fsp, 0, pst->st_ex_size, space_to_write);
-	if (ret == -1 && errno == ENOSPC) {
-		return -1;
-	}
-	if (ret == 0) {
-		return 0;
-	}
-	DEBUG(10,("[CEPH] strict_allocate_ftruncate: SMB_VFS_FALLOCATE failed with "
-		"error %d. Falling back to slow manual allocation\n", errno));
-
-	/* available disk space is enough or not? */
-	space_avail =
-	    get_dfree_info(fsp->conn, fsp->fsp_name, &bsize, &dfree, &dsize);
-	/* space_avail is 1k blocks */
-	if (space_avail == (uint64_t)-1 ||
-			((uint64_t)space_to_write/1024 > space_avail) ) {
-		errno = ENOSPC;
-		return -1;
-	}
-
-	/* Write out the real space on disk. */
-	return vfs_slow_fallocate(fsp, pst->st_ex_size, space_to_write);
+	result = ceph_fallocate(handle->data, fsp->fh->fd, 0, pst->st_ex_size,
+				space_to_write);
+	WRAP_RETURN(result);
 }
 
 static int cephwrap_ftruncate(struct vfs_handle_struct *handle, files_struct *fsp, off_t len)
 {
 	int result = -1;
-	SMB_STRUCT_STAT st;
-	char c = 0;
-	off_t currpos;
 
 	DBG_DEBUG("[CEPH] ftruncate(%p, %p, %llu\n", handle, fsp, llu(len));
 
 	if (lp_strict_allocate(SNUM(fsp->conn))) {
-		result = strict_allocate_ftruncate(handle, fsp, len);
-		return result;
+		return strict_allocate_ftruncate(handle, fsp, len);
 	}
 
-	/* we used to just check HAVE_FTRUNCATE_EXTEND and only use
-	   sys_ftruncate if the system supports it. Then I discovered that
-	   you can have some filesystems that support ftruncate
-	   expansion and some that don't! On Linux fat can't do
-	   ftruncate extend but ext2 can. */
-
 	result = ceph_ftruncate(handle->data, fsp->fh->fd, len);
-	if (result == 0)
-		goto done;
-
-	/* According to W. R. Stevens advanced UNIX prog. Pure 4.3 BSD cannot
-	   extend a file with ftruncate. Provide alternate implementation
-	   for this */
-	currpos = SMB_VFS_LSEEK(fsp, 0, SEEK_CUR);
-	if (currpos == -1) {
-		goto done;
-	}
-
-	/* Do an fstat to see if the file is longer than the requested
-	   size in which case the ftruncate above should have
-	   succeeded or shorter, in which case seek to len - 1 and
-	   write 1 byte of zero */
-	if (SMB_VFS_FSTAT(fsp, &st) == -1) {
-		goto done;
-	}
-
-#ifdef S_ISFIFO
-	if (S_ISFIFO(st.st_ex_mode)) {
-		result = 0;
-		goto done;
-	}
-#endif
-
-	if (st.st_ex_size == len) {
-		result = 0;
-		goto done;
-	}
-
-	if (st.st_ex_size > len) {
-		/* the sys_ftruncate should have worked */
-		goto done;
-	}
-
-	if (SMB_VFS_LSEEK(fsp, len-1, SEEK_SET) != len -1)
-		goto done;
-
-	if (SMB_VFS_WRITE(fsp, &c, 1)!=1)
-		goto done;
-
-	/* Seek to where we were */
-	if (SMB_VFS_LSEEK(fsp, currpos, SEEK_SET) != currpos)
-		goto done;
-	result = 0;
-
-  done:
-
-	return result;
+	WRAP_RETURN(result);
 }
 
 static int cephwrap_fallocate(struct vfs_handle_struct *handle,