Hi Chao, On 06/26, Chao Yu wrote: > Hi Jaegeuk, > > On 2017/6/25 0:25, Jaegeuk Kim wrote: > > - punch_hole > > - fill_zero > > - f2fs_lock_op > > - get_new_data_page > > - lock_page > > > > - f2fs_write_data_pages > > - lock_page > > - do_write_data_page > > - f2fs_lock_op > > Good catch! > > With this implementation, page writeback can fail due to concurrent > checkpoint, > this will make fsync/atomic_commit which trigger synchronous write failed > randomly. > > How about unifying the lock order in punch_hole as one in writepages for > regular > inode? We can add one more parameter in get_new_data_page to indicate whether > callee needs to lock cp_rwsem.
Currently, there would be some places to keep cp_rwsem -> page.lock, which seems not simple to change the lock order with page.lock -> cp_rwsem. IMO, we can retry flushing data in f2fs_sync_file, once it gets -EAGAIN. Any thoughts? > > Thanks, > > > > > Signed-off-by: Jaegeuk Kim <[email protected]> > > --- > > fs/f2fs/data.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > index 7d3af48d34a9..9141bd19a902 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -1404,8 +1404,9 @@ int do_write_data_page(struct f2fs_io_info *fio) > > } > > } > > > > - if (fio->need_lock == LOCK_REQ) > > - f2fs_lock_op(fio->sbi); > > + /* Deadlock due to between page->lock and f2fs_lock_op */ > > + if (fio->need_lock == LOCK_REQ && !f2fs_trylock_op(fio->sbi)) > > + return -EAGAIN; > > > > err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE); > > if (err) > >
