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-rw-r--r--mm/page-writeback.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2970e35fd03f..eb277bdd4c5d 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -868,9 +868,10 @@ int write_cache_pages(struct address_space *mapping,
868 int done = 0; 868 int done = 0;
869 struct pagevec pvec; 869 struct pagevec pvec;
870 int nr_pages; 870 int nr_pages;
871 pgoff_t uninitialized_var(writeback_index);
871 pgoff_t index; 872 pgoff_t index;
872 pgoff_t end; /* Inclusive */ 873 pgoff_t end; /* Inclusive */
873 int scanned = 0; 874 int cycled;
874 int range_whole = 0; 875 int range_whole = 0;
875 long nr_to_write = wbc->nr_to_write; 876 long nr_to_write = wbc->nr_to_write;
876 877
@@ -881,14 +882,19 @@ int write_cache_pages(struct address_space *mapping,
881 882
882 pagevec_init(&pvec, 0); 883 pagevec_init(&pvec, 0);
883 if (wbc->range_cyclic) { 884 if (wbc->range_cyclic) {
884 index = mapping->writeback_index; /* Start from prev offset */ 885 writeback_index = mapping->writeback_index; /* prev offset */
886 index = writeback_index;
887 if (index == 0)
888 cycled = 1;
889 else
890 cycled = 0;
885 end = -1; 891 end = -1;
886 } else { 892 } else {
887 index = wbc->range_start >> PAGE_CACHE_SHIFT; 893 index = wbc->range_start >> PAGE_CACHE_SHIFT;
888 end = wbc->range_end >> PAGE_CACHE_SHIFT; 894 end = wbc->range_end >> PAGE_CACHE_SHIFT;
889 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) 895 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
890 range_whole = 1; 896 range_whole = 1;
891 scanned = 1; 897 cycled = 1; /* ignore range_cyclic tests */
892 } 898 }
893retry: 899retry:
894 while (!done && (index <= end) && 900 while (!done && (index <= end) &&
@@ -897,7 +903,6 @@ retry:
897 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { 903 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
898 unsigned i; 904 unsigned i;
899 905
900 scanned = 1;
901 for (i = 0; i < nr_pages; i++) { 906 for (i = 0; i < nr_pages; i++) {
902 struct page *page = pvec.pages[i]; 907 struct page *page = pvec.pages[i];
903 908
@@ -915,7 +920,11 @@ retry:
915 continue; 920 continue;
916 } 921 }
917 922
918 if (!wbc->range_cyclic && page->index > end) { 923 if (page->index > end) {
924 /*
925 * can't be range_cyclic (1st pass) because
926 * end == -1 in that case.
927 */
919 done = 1; 928 done = 1;
920 unlock_page(page); 929 unlock_page(page);
921 continue; 930 continue;
@@ -946,13 +955,15 @@ retry:
946 pagevec_release(&pvec); 955 pagevec_release(&pvec);
947 cond_resched(); 956 cond_resched();
948 } 957 }
949 if (!scanned && !done) { 958 if (!cycled) {
950 /* 959 /*
960 * range_cyclic:
951 * We hit the last page and there is more work to be done: wrap 961 * We hit the last page and there is more work to be done: wrap
952 * back to the start of the file 962 * back to the start of the file
953 */ 963 */
954 scanned = 1; 964 cycled = 1;
955 index = 0; 965 index = 0;
966 end = writeback_index - 1;
956 goto retry; 967 goto retry;
957 } 968 }
958 if (!wbc->no_nrwrite_index_update) { 969 if (!wbc->no_nrwrite_index_update) {