On Thu, Nov 08, 2012 at 12:08:49PM +0100, Lukas Czerner wrote: > + down_read(&EXT4_I(inode)->i_data_sem); > error = ext4_ext_walk_space(inode, start_blk, len_blks, > ext4_ext_fiemap_cb, fieinfo); > + up_read(&EXT4_I(inode)->i_data_sem); Can this deadlock? ext4_ext_fiemap_cb() seems to be doing all kinds of exciting things that might also try and acquire the i_data_sem, like GFP_KERNEL allocs (reclaim -> writepage) and copying to userspace (mmap fault -> readpage -> get blocks). It seems like the safer fix is to broaden the sampling lock coverage to include referencing all the extent data but to release it around the callback. No? - z -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
