Fix 'arc_c < arc_c_min' panic

Strictly enforce keeping 'arc_c >= arc_c_min'.  The ASSERTs are
left in place to catch this in a debug build but logic has been
added to gracefully handle in a production build.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3904
This commit is contained in:
Brian Behlendorf 2015-10-13 09:17:01 -07:00
parent 8f90f7372a
commit 935434ef01

View File

@ -3757,7 +3757,8 @@ arc_adapt(int bytes, arc_state_t *state)
* If we're within (2 * maxblocksize) bytes of the target * If we're within (2 * maxblocksize) bytes of the target
* cache size, increment the target cache size * cache size, increment the target cache size
*/ */
VERIFY3U(arc_c, >=, 2ULL << SPA_MAXBLOCKSHIFT); ASSERT3U(arc_c, >=, 2ULL << SPA_MAXBLOCKSHIFT);
arc_c = MAX(arc_c, 2ULL << SPA_MAXBLOCKSHIFT);
if (arc_size >= arc_c - (2ULL << SPA_MAXBLOCKSHIFT)) { if (arc_size >= arc_c - (2ULL << SPA_MAXBLOCKSHIFT)) {
atomic_add_64(&arc_c, (int64_t)bytes); atomic_add_64(&arc_c, (int64_t)bytes);
if (arc_c > arc_c_max) if (arc_c > arc_c_max)