On 2017/7/26 9:29, Jaegeuk Kim wrote: > This patch resolves the below scenario. > > == Process 1 == == Process 2 == > open(w) open(rw) > begin > write(new_#1) > process_crash > f_op->flush > locks_remove_posix > f_op>release > read (new_#1) > > In order to avoid corrupted database caused by new_#1, we must do roll-back > at process_crash time. In order to check that, this patch keeps task which > triggers transaction begin, and does roll-back in f_op->flush before removing > file locks. > > Signed-off-by: Jaegeuk Kim <[email protected]>
Reviewed-by: Chao Yu <[email protected]> Thanks, > --- > fs/f2fs/f2fs.h | 1 + > fs/f2fs/file.c | 18 ++++++++++++++++++ > 2 files changed, 19 insertions(+) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index a336021b777f..3e48c2ac2f21 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -565,6 +565,7 @@ struct f2fs_inode_info { > struct list_head dirty_list; /* dirty list for dirs and files */ > struct list_head gdirty_list; /* linked in global dirty list */ > struct list_head inmem_pages; /* inmemory pages managed by f2fs */ > + struct task_struct *inmem_task; /* store inmemory task */ > struct mutex inmem_lock; /* lock for inmemory pages */ > struct extent_tree *extent_tree; /* cached extent_tree entry */ > struct rw_semaphore dio_rwsem[2];/* avoid racing between dio and gc */ > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index 0f4dbeb61845..cb0a013859e6 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -1502,6 +1502,22 @@ static int f2fs_release_file(struct inode *inode, > struct file *filp) > return 0; > } > > +static int f2fs_file_flush(struct file *file, fl_owner_t id) > +{ > + struct inode *inode = file_inode(file); > + > + /* > + * If the process doing a transaction is crashed, we should do > + * roll-back. Otherwise, other reader/write can see corrupted database > + * until all the writers close its file. Since this should be done > + * before dropping file lock, it needs to do in ->flush. > + */ > + if (f2fs_is_atomic_file(inode) && > + F2FS_I(inode)->inmem_task == current) > + drop_inmem_pages(inode); > + return 0; > +} > + > static int f2fs_ioc_getflags(struct file *filp, unsigned long arg) > { > struct inode *inode = file_inode(filp); > @@ -1608,6 +1624,7 @@ static int f2fs_ioc_start_atomic_write(struct file > *filp) > } > > inc_stat: > + F2FS_I(inode)->inmem_task = current; > stat_inc_atomic_write(inode); > stat_update_max_atomic_write(inode); > out: > @@ -2514,6 +2531,7 @@ const struct file_operations f2fs_file_operations = { > .open = f2fs_file_open, > .release = f2fs_release_file, > .mmap = f2fs_file_mmap, > + .flush = f2fs_file_flush, > .fsync = f2fs_sync_file, > .fallocate = f2fs_fallocate, > .unlocked_ioctl = f2fs_ioctl, >
