f2fs: fix a deadlock for summary page lock vs. sentry_lock

In f2fs_gc:                      In f2fs_replace_block:
 - lock_page(sum_page)
  - check_valid_map()            - mutex_lock(sentry_lock)
   - mutex_lock(sentry_lock)     - change_curseg()
                                  - lock_page(sum_page)

This patch fixes the deadlock condition.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2015-05-28 18:19:17 -07:00
parent e5e0906b6b
commit 9236cac566
1 changed files with 10 additions and 1 deletions

View File

@ -750,6 +750,15 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
sum = page_address(sum_page);
/*
* this is to avoid deadlock:
* - lock_page(sum_page) - f2fs_replace_block
* - check_valid_map() - mutex_lock(sentry_lock)
* - mutex_lock(sentry_lock) - change_curseg()
* - lock_page(sum_page)
*/
unlock_page(sum_page);
switch (GET_SUM_TYPE((&sum->footer))) {
case SUM_TYPE_NODE:
gc_node_segment(sbi, sum->entries, segno, gc_type);
@ -763,7 +772,7 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type);
stat_inc_call_count(sbi->stat_info);
f2fs_put_page(sum_page, 1);
f2fs_put_page(sum_page, 0);
}
int f2fs_gc(struct f2fs_sb_info *sbi)