From: Jonathan Lebon <jonathan@jlebon.com>
Date: Thu, 4 Jan 2024 16:14:40 +0000 (-0500)
Subject: lib/deploy: Add safety margin in early prune space check
X-Git-Tag: archive/raspbian/2024.8-1+rpi1^2~7^2~7^2~8^2
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=cc5747a60561db0b6c8a534d1556605599192a03;p=ostree.git

lib/deploy: Add safety margin in early prune space check

There are a few things the estimator doesn't account for, e.g. writing
the new BLS entries. Rather than trying to perfect it (since I think we
should change approach entirely -- see previous commit message), just
add a 1M margin to the space check.
---

diff --git a/src/libostree/ostree-sysroot-deploy.c b/src/libostree/ostree-sysroot-deploy.c
index d6f3dcb6..5c941d51 100644
--- a/src/libostree/ostree-sysroot-deploy.c
+++ b/src/libostree/ostree-sysroot-deploy.c
@@ -59,6 +59,12 @@
   SD_ID128_MAKE (e8, 64, 6c, d6, 3d, ff, 46, 25, b7, 79, 09, a8, e7, a4, 09, 94)
 #endif
 
+/* How much additional space we require available on top of what we accounted
+ * during the early prune fallocate space check. This accounts for anything not
+ * captured directly by `get_kernel_layout_size()` like writing new BLS entries.
+ */
+#define EARLY_PRUNE_SAFETY_MARGIN_SIZE (1 << 20) /* 1 MB */
+
 /*
  * Like symlinkat() but overwrites (atomically) an existing
  * symlink.
@@ -2541,6 +2547,9 @@ dfd_fallocate_check (int dfd, off_t len, gboolean *out_passed, GError **error)
   if (!glnx_open_tmpfile_linkable_at (dfd, ".", O_WRONLY | O_CLOEXEC, &tmpf, error))
     return FALSE;
 
+  /* add the safety margin */
+  len += EARLY_PRUNE_SAFETY_MARGIN_SIZE;
+
   *out_passed = TRUE;
   /* There's glnx_try_fallocate, but not with the same error semantics. */
   if (TEMP_FAILURE_RETRY (fallocate (tmpf.fd, 0, 0, len)) < 0)