Abort transaction if there's not enough free space on disk.

Close #7.

NEWS

@@ -1,5 +1,10 @@
 xbps-0.38 (???):
 
+ * Before accepting a transaction, xbps now checks if there's enough free space
+   on the target rootdir (on disk) to proceed with the operation. In code terms,
+   xbps_transaction_prepare() now returns ENOSPC if the size of the transaction
+   exceeds the size of the free space. Close issue #7.
+
  * When installing or updating packages, now proper statistics are generated
    when a binary package from a repository repository exists in the cachedir,
    and when a package has the "preserve" property.

bin/xbps-install/transaction.c

@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2009-2013 Juan Romero Pardines.
+ * Copyright (c) 2009-2014 Juan Romero Pardines.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -97,7 +97,7 @@ show_package_list(xbps_object_iterator_t iter, const char *match, int cols)
 static int
 show_transaction_sizes(struct transaction *trans, int cols)
 {
-	uint64_t dlsize = 0, instsize = 0, rmsize = 0;
+	uint64_t dlsize = 0, instsize = 0, rmsize = 0, disk_free_size = 0;
 	char size[8];
 
 	/*
@@ -139,10 +139,10 @@ show_transaction_sizes(struct transaction *trans, int cols)
 	 * Show total download/installed/removed size for all required packages.
 	 */
 	xbps_dictionary_get_uint64(trans->d, "total-download-size", &dlsize);
-	xbps_dictionary_get_uint64(trans->d, "total-installed-size",
-	    &instsize);
+	xbps_dictionary_get_uint64(trans->d, "total-installed-size", &instsize);
 	xbps_dictionary_get_uint64(trans->d, "total-removed-size", &rmsize);
-	if (dlsize || instsize || rmsize)
+	xbps_dictionary_get_uint64(trans->d, "disk-free-size", &disk_free_size);
+	if (dlsize || instsize || rmsize || disk_free_size)
 		printf("\n");
 
 	if (dlsize) {
@@ -169,6 +169,14 @@ show_transaction_sizes(struct transaction *trans, int cols)
 		}
 		printf("Size freed on disk:           %6s\n", size);
 	}
+	if (disk_free_size) {
+		if (xbps_humanize_number(size, (int64_t)disk_free_size) == -1) {
+			xbps_error_printf("humanize_number3 returns "
+			    "%s\n", strerror(errno));
+			return -1;
+		}
+		printf("Free space on disk:           %6s\n", size);
+	}
 	printf("\n");
 
 	return 0;

include/xbps.h.in

@@ -1121,6 +1121,8 @@ int xbps_transaction_autoremove_pkgs(struct xbps_handle *xhp);
  *  array of strings object in xhp->transd dictionary).
  * @retval EAGAIN if there are package conflicts in transaction ("conflicts"
  *  array of strings object in xhp->transd dictionary).
+ * @retval ENOSPC Not enough free space on target rootdir to continue with the
+ *  transaction.
  * @retval EINVAL There was an error sorting packages or computing the transaction
  * sizes.
  */

lib/transaction_dictionary.c

@@ -28,6 +28,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/statvfs.h>
 
 #include "xbps_api_impl.h"
 
@@ -58,6 +59,8 @@ compute_transaction_stats(struct xbps_handle *xhp)
 	xbps_dictionary_t pkg_metad;
 	xbps_object_iterator_t iter;
 	xbps_object_t obj;
+	struct statvfs svfs;
+	unsigned long rootdir_free_size;
 	uint64_t tsize, dlsize, instsize, rmsize;
 	uint32_t inst_pkgcnt, up_pkgcnt, cf_pkgcnt, rm_pkgcnt;
 	const char *tract, *pkgver, *repo;
@@ -101,6 +104,8 @@ compute_transaction_stats(struct xbps_handle *xhp)
 			    !xbps_binpkg_exists(xhp, obj)) {
 				xbps_dictionary_get_uint64(obj,
 				    "filename-size", &tsize);
+				/* signature file: 512 bytes */
+				tsize += 512;
 				dlsize += tsize;
 				instsize += tsize;
 			}
@@ -159,6 +164,21 @@ compute_transaction_stats(struct xbps_handle *xhp)
 				"total-removed-size", rmsize))
 		return EINVAL;
 
+	/* Get free space from target rootdir: return ENOSPC if there's not enough space */
+	if (statvfs(xhp->rootdir, &svfs) == -1) {
+		xbps_dbg_printf(xhp, "%s: statvfs failed: %s\n", __func__, strerror(errno));
+		return EINVAL;
+	}
+	/* compute free space on disk */
+	rootdir_free_size = svfs.f_bfree * svfs.f_bsize - instsize;
+
+	if (!xbps_dictionary_set_uint64(xhp->transd,
+				"disk-free-size", rootdir_free_size))
+		return EINVAL;
+
+	if (instsize > rootdir_free_size)
+		return ENOSPC;
+
 	return 0;
 }