diff options
| author | Zhenzhong Duan <zhenzhong.duan@intel.com> | 2022-10-17 15:53:50 +0800 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2023-02-06 19:22:57 +0100 |
| commit | ddbe628c97c3a2d211c6d96383cb4063ac3ad0f9 (patch) | |
| tree | 24b3525ac18877715b0c449304aa29ca14b234c2 | |
| parent | 6720c2b32725e6ac404f22851a0ecd0a71d0cbe2 (diff) | |
multifd: Fix a race on reading MultiFDPages_t.block
In multifd_queue_page() MultiFDPages_t.block is checked twice.
Between the two checks, MultiFDPages_t.block may be reset to NULL
by multifd thread. This lead to the 2nd check always true then a
redundant page submitted to multifd thread again.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
| -rw-r--r-- | migration/multifd.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/migration/multifd.c b/migration/multifd.c index eeb4fb87ee..ad89293b4e 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -442,6 +442,7 @@ static int multifd_send_pages(QEMUFile *f) int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset) { MultiFDPages_t *pages = multifd_send_state->pages; + bool changed = false; if (!pages->block) { pages->block = block; @@ -454,14 +455,16 @@ int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset) if (pages->num < pages->allocated) { return 1; } + } else { + changed = true; } if (multifd_send_pages(f) < 0) { return -1; } - if (pages->block != block) { - return multifd_queue_page(f, block, offset); + if (changed) { + return multifd_queue_page(f, block, offset); } return 1; |