f2fs: avoid race for summary information

In order to do GC more reliably, I'd like to lock the vicitm summary page
until its GC is completed, and also prevent any checkpoint process.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 54aceb2e1d090ec5dde9cbfe8155dc865e3ac71c..54ac13da950d04036094b5311523772943925e98 100644 (file)
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -641,12 +641,6 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
        if (IS_ERR(sum_page))
                return;
 
-       /*
-        * CP needs to lock sum_page. In this time, we don't need
-        * to lock this page, because this summary page is not gone anywhere.
-        * Also, this page is not gonna be updated before GC is done.
-        */
-       unlock_page(sum_page);
        sum = page_address(sum_page);
 
        switch (GET_SUM_TYPE((&sum->footer))) {
@@ -660,7 +654,7 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
        stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
        stat_inc_call_count(sbi->stat_info);
 
-       f2fs_put_page(sum_page, 0);
+       f2fs_put_page(sum_page, 1);
 }
 
 int f2fs_gc(struct f2fs_sb_info *sbi)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index c5360b743fec7388bc045829a2f96135da3d6f31..7555fb79d85bcf7dbf8d15132e77c5321ecaedf1 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1148,7 +1148,7 @@ static int f2fs_write_node_pages(struct address_space *mapping,
 
        /* First check balancing cached NAT entries */
        if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK)) {
-               write_checkpoint(sbi, false);
+               f2fs_sync_fs(sbi->sb, true);
                return 0;
        }
 

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index ea325c8cf8166ad5676d803f5e3c7f47debf0a09..161e6c6cebf79bc62466525373774a9cdc384390 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -137,10 +137,13 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
        if (!sbi->s_dirty && !get_pages(sbi, F2FS_DIRTY_NODES))
                return 0;
 
-       if (sync)
+       if (sync) {
+               mutex_lock(&sbi->gc_mutex);
                write_checkpoint(sbi, false);
-       else
+               mutex_unlock(&sbi->gc_mutex);
+       } else {
                f2fs_balance_fs(sbi);
+       }
 
        return 0;
 }