prune: update free-space filter when no max-space set

tonistiigi · jedevc · commit 36852ce82849 · 2025-04-08T10:44:36.000+01:00
When free-space filter is set without max-space or reserved-space
filter, the behaviour is that if the filter matches some records
then these records would be pruned, but if it doesn't match any
(there are more free space than filter sets already) then the keepBytes
would be left to 0, resulting records to be deleted as if no storage
constraint was set at all.

Signed-off-by: Tonis Tiigi &lt;tonistiigi@gmail.com&gt;
diff --git a/cache/manager.go b/cache/manager.go
@@ -1092,6 +1092,9 @@ func calculateKeepBytes(totalSize int64, dstat disk.DiskStat, opt client.PruneIn
 		} else {
 			keepBytes = min(keepBytes, totalSize-excess)
 		}
+	} else if opt.MinFreeSpace != 0 && keepBytes == 0 {
+		// if only minFreeSpace is set and it doesn't match then we don't delete anything
+		keepBytes = totalSize
 	}
 
 	// but make sure we don't take the total below the reserved space

Original file line number	Diff line number	Diff line change
`@@ -1092,6 +1092,9 @@ func calculateKeepBytes(totalSize int64, dstat disk.DiskStat, opt client.PruneIn`
`1092`	`1092`	`} else {`
`1093`	`1093`	`keepBytes = min(keepBytes, totalSize-excess)`
`1094`	`1094`	`}`
	`1095`	`+ } else if opt.MinFreeSpace != 0 && keepBytes == 0 {`
	`1096`	`+ // if only minFreeSpace is set and it doesn't match then we don't delete anything`
	`1097`	`+ keepBytes = totalSize`
`1095`	`1098`	`}`
`1096`	`1099`
`1097`	`1100`	`// but make sure we don't take the total below the reserved space`