Commit a303b0ac authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
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f2fs: fix to avoid GC/mmap race with f2fs_truncate() 



It missed to hold i_gc_rwsem and i_map_sem around f2fs_truncate()
in f2fs_file_write_iter() to avoid racing with background GC and
mmap, fix it.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent b5d15199

fs/f2fs/file.c

+6 −1
Original line number Diff line number Diff line
@@ -4443,8 +4443,13 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 
		clear_inode_flag(inode, FI_NO_PREALLOC);



		/* if we couldn't write data, we should deallocate blocks. */

		if (preallocated && i_size_read(inode) < target_size)

		if (preallocated && i_size_read(inode) < target_size) {

			down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

			down_write(&F2FS_I(inode)->i_mmap_sem);

			f2fs_truncate(inode);

			up_write(&F2FS_I(inode)->i_mmap_sem);

			up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);

		}



		if (ret > 0)

			f2fs_update_iostat(F2FS_I_SB(inode), APP_WRITE_IO, ret);