Messages in this thread Patch in this message |  | | From | Chao Yu <> | Subject | [PATCH 1/5] f2fs: fix race in between GC and atomic open | Date | Wed, 18 Apr 2018 17:45:01 +0800 |
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Thread GC thread - f2fs_ioc_start_atomic_write - get_dirty_pages - filemap_write_and_wait_range - f2fs_gc - do_garbage_collect - gc_data_segment - move_data_page - f2fs_is_atomic_file - set_page_dirty - set_inode_flag(, FI_ATOMIC_FILE)
Dirty data page can still be generated by GC in race condition as above call stack.
This patch adds fi->dio_rwsem[WRITE] in f2fs_ioc_start_atomic_write to avoid such race.
Signed-off-by: Chao Yu <yuchao0@huawei.com> --- fs/f2fs/file.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 78b3a58cfe21..408471bf4799 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1677,6 +1677,8 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) inode_lock(inode); + down_write(&F2FS_I(inode)->dio_rwsem[WRITE]); + if (f2fs_is_atomic_file(inode)) goto out; @@ -1702,6 +1704,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) stat_inc_atomic_write(inode); stat_update_max_atomic_write(inode); out: + up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); inode_unlock(inode); mnt_drop_write_file(filp); return ret; -- 2.15.0.55.gc2ece9dc4de6
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