1 files changed, 63 insertions, 23 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index eb2bee8b7fbf..05a1c42e25bf 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -50,7 +50,10 @@ struct extent_page_data {
         /* tells writepage not to lock the state bits for this range
          * it still does the unlocking
          */
-        int extent_locked;
+        unsigned int extent_locked:1;
+
+        /* tells the submit_bio code to use a WRITE_SYNC */
+        unsigned int sync_io:1;
 };
 
 int __init extent_io_init(void)
@@ -2101,6 +2104,16 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
         return ret;
 }
 
+static noinline void update_nr_written(struct page *page,
+                                      struct writeback_control *wbc,
+                                      unsigned long nr_written)
+{
+        wbc->nr_to_write -= nr_written;
+        if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
+            wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
+                page->mapping->writeback_index = page->index + nr_written;
+}
+
 /*
  * the writepage semantics are similar to regular writepage.  extent
  * records are inserted to lock ranges in the tree, and as dirty areas
@@ -2136,8 +2149,14 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
         u64 delalloc_end;
         int page_started;
         int compressed;
+        int write_flags;
         unsigned long nr_written = 0;
 
+        if (wbc->sync_mode == WB_SYNC_ALL)
+                write_flags = WRITE_SYNC_PLUG;
+        else
+                write_flags = WRITE;
+
         WARN_ON(!PageLocked(page));
         pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
         if (page->index > end_index ||
@@ -2164,6 +2183,12 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
         delalloc_end = 0;
         page_started = 0;
         if (!epd->extent_locked) {
+                /*
+                 * make sure the wbc mapping index is at least updated
+                 * to this page.
+                 */
+                update_nr_written(page, wbc, 0);
+
                 while (delalloc_end < page_end) {
                         nr_delalloc = find_lock_delalloc_range(inode, tree,
                                                        page,
@@ -2185,7 +2210,13 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                  */
                 if (page_started) {
                         ret = 0;
-                        goto update_nr_written;
+                        /*
+                         * we've unlocked the page, so we can't update
+                         * the mapping's writeback index, just update
+                         * nr_to_write.
+                         */
+                        wbc->nr_to_write -= nr_written;
+                        goto done_unlocked;
                 }
         }
         lock_extent(tree, start, page_end, GFP_NOFS);
@@ -2198,13 +2229,18 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                 if (ret == -EAGAIN) {
                         unlock_extent(tree, start, page_end, GFP_NOFS);
                         redirty_page_for_writepage(wbc, page);
+                        update_nr_written(page, wbc, nr_written);
                         unlock_page(page);
                         ret = 0;
-                        goto update_nr_written;
+                        goto done_unlocked;
                 }
         }
 
-        nr_written++;
+        /*
+         * we don't want to touch the inode after unlocking the page,
+         * so we update the mapping writeback index now
+         */
+        update_nr_written(page, wbc, nr_written + 1);
 
         end = page_end;
         if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0))
@@ -2314,9 +2350,9 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                                        (unsigned long long)end);
                         }
 
-                        ret = submit_extent_page(WRITE, tree, page, sector,
-                                                 iosize, pg_offset, bdev,
-                                                 &epd->bio, max_nr,
+                        ret = submit_extent_page(write_flags, tree, page,
+                                                 sector, iosize, pg_offset,
+                                                 bdev, &epd->bio, max_nr,
                                                  end_bio_extent_writepage,
                                                  0, 0, 0);
                         if (ret)
@@ -2336,11 +2372,8 @@ done:
                 unlock_extent(tree, unlock_start, page_end, GFP_NOFS);
         unlock_page(page);
 
-update_nr_written:
-        wbc->nr_to_write -= nr_written;
-        if (wbc->range_cyclic || (wbc->nr_to_write > 0 &&
-            wbc->range_start == 0 && wbc->range_end == LLONG_MAX))
-                page->mapping->writeback_index = page->index + nr_written;
+done_unlocked:
+
         return 0;
 }
 
@@ -2460,15 +2493,23 @@ retry:
         return ret;
 }
 
-static noinline void flush_write_bio(void *data)
+static void flush_epd_write_bio(struct extent_page_data *epd)
 {
-        struct extent_page_data *epd = data;
         if (epd->bio) {
-                submit_one_bio(WRITE, epd->bio, 0, 0);
+                if (epd->sync_io)
+                        submit_one_bio(WRITE_SYNC, epd->bio, 0, 0);
+                else
+                        submit_one_bio(WRITE, epd->bio, 0, 0);
                 epd->bio = NULL;
         }
 }
 
+static noinline void flush_write_bio(void *data)
+{
+        struct extent_page_data *epd = data;
+        flush_epd_write_bio(epd);
+}
+
 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
                           get_extent_t *get_extent,
                           struct writeback_control *wbc)
@@ -2480,23 +2521,22 @@ int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
                 .tree = tree,
                 .get_extent = get_extent,
                 .extent_locked = 0,
+                .sync_io = wbc->sync_mode == WB_SYNC_ALL,
         };
         struct writeback_control wbc_writepages = {
                 .bdi            = wbc->bdi,
-                .sync_mode      = WB_SYNC_NONE,
+                .sync_mode      = wbc->sync_mode,
                 .older_than_this = NULL,
                 .nr_to_write    = 64,
                 .range_start    = page_offset(page) + PAGE_CACHE_SIZE,
                 .range_end      = (loff_t)-1,
         };
 
-
         ret = __extent_writepage(page, wbc, &epd);
 
         extent_write_cache_pages(tree, mapping, &wbc_writepages,
                                  __extent_writepage, &epd, flush_write_bio);
-        if (epd.bio)
-                submit_one_bio(WRITE, epd.bio, 0, 0);
+        flush_epd_write_bio(&epd);
         return ret;
 }
 
@@ -2515,6 +2555,7 @@ int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
                 .tree = tree,
                 .get_extent = get_extent,
                 .extent_locked = 1,
+                .sync_io = mode == WB_SYNC_ALL,
         };
         struct writeback_control wbc_writepages = {
                 .bdi            = inode->i_mapping->backing_dev_info,
@@ -2540,8 +2581,7 @@ int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
                 start += PAGE_CACHE_SIZE;
         }
 
-        if (epd.bio)
-                submit_one_bio(WRITE, epd.bio, 0, 0);
+        flush_epd_write_bio(&epd);
         return ret;
 }
 
@@ -2556,13 +2596,13 @@ int extent_writepages(struct extent_io_tree *tree,
                 .tree = tree,
                 .get_extent = get_extent,
                 .extent_locked = 0,
+                .sync_io = wbc->sync_mode == WB_SYNC_ALL,
         };
 
         ret = extent_write_cache_pages(tree, mapping, wbc,
                                        __extent_writepage, &epd,
                                        flush_write_bio);
-        if (epd.bio)
-                submit_one_bio(WRITE, epd.bio, 0, 0);
+        flush_epd_write_bio(&epd);
         return ret;
 }