diff options
| -rw-r--r-- | mm/swapfile.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 9c85bd46ab7f..b0a9071cfe1d 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -664,12 +664,15 @@ static bool cluster_scan_range(struct swap_info_struct *si, return true; } -static void cluster_alloc_range(struct swap_info_struct *si, struct swap_cluster_info *ci, +static bool cluster_alloc_range(struct swap_info_struct *si, struct swap_cluster_info *ci, unsigned int start, unsigned char usage, unsigned int order) { unsigned int nr_pages = 1 << order; + if (!(si->flags & SWP_WRITEOK)) + return false; + if (cluster_is_free(ci)) { if (nr_pages < SWAPFILE_CLUSTER) { list_move_tail(&ci->list, &si->nonfull_clusters[order]); @@ -690,6 +693,8 @@ static void cluster_alloc_range(struct swap_info_struct *si, struct swap_cluster list_move_tail(&ci->list, &si->full_clusters); ci->flags = CLUSTER_FLAG_FULL; } + + return true; } static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, unsigned long offset, @@ -713,7 +718,10 @@ static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, unsigne while (offset <= end) { if (cluster_scan_range(si, ci, offset, nr_pages)) { - cluster_alloc_range(si, ci, offset, usage, order); + if (!cluster_alloc_range(si, ci, offset, usage, order)) { + offset = SWAP_NEXT_INVALID; + goto done; + } *foundp = offset; if (ci->count == SWAPFILE_CLUSTER) { offset = SWAP_NEXT_INVALID; @@ -805,7 +813,11 @@ new_cluster: if (!list_empty(&si->free_clusters)) { ci = list_first_entry(&si->free_clusters, struct swap_cluster_info, list); offset = alloc_swap_scan_cluster(si, cluster_offset(si, ci), &found, order, usage); - VM_BUG_ON(!found); + /* + * Either we didn't touch the cluster due to swapoff, + * or the allocation must success. + */ + VM_BUG_ON((si->flags & SWP_WRITEOK) && !found); goto done; } @@ -1041,6 +1053,8 @@ static int cluster_alloc_swap(struct swap_info_struct *si, VM_BUG_ON(!si->cluster_info); + si->flags += SWP_SCANNING; + while (n_ret < nr) { unsigned long offset = cluster_alloc_swap_entry(si, order, usage); @@ -1049,6 +1063,8 @@ static int cluster_alloc_swap(struct swap_info_struct *si, slots[n_ret++] = swp_entry(si->type, offset); } + si->flags -= SWP_SCANNING; + return n_ret; } |