On Wed 08-05-19 19:09:56, Amir Goldstein wrote: > On Tue, May 7, 2019 at 10:12 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > Yes, I much prefer this solution myself and I will follow up with it, > > but it would not be honest to suggest said solution as a stable fix > > to the performance regression that was introduced in v5.1. > > I think is it better if you choose between lesser evil: > > v1 with ifdef CONFIG_FSNOTIFY to fix build issue > > v2 as subtle as it is > > OR another obviously safe stable fix that you can think of > > > > The change of cleansing d_delete() from fsnotify_nameremove() > > requires more research and is anyway not stable tree material - > > if not for the level of complexity, then because all the users of > > FS_DELETE from pseudo and clustered filesystems need more time > > to find regressions (we do not have test coverage for those in LTP). > > > > Something like this: > https://github.com/amir73il/linux/commits/fsnotify_nameremove > > Only partially tested. Obviously haven't tested all callers. Not quite. I'd add the fsnotify_nameremove() call also to simple_rmdir() and simple_unlink(). That takes care of: arch/s390/hypfs/inode.c, drivers/infiniband/hw/qib/qib_fs.c, fs/configfs/dir.c, fs/debugfs/inode.c, fs/tracefs/inode.c, net/sunrpc/rpc_pipe.c So you're left only with: drivers/usb/gadget/function/f_fs.c, fs/btrfs/ioctl.c, fs/devpts/inode.c, fs/reiserfs/xattr.c Out of these drivers/usb/gadget/function/f_fs.c and fs/reiserfs/xattr.c actually also don't want the notifications to be generated. They don't generate events on file creation AFAICS and at least in case of reiserfs I know that xattrs are handled in "hidden" system files so notification does not make any sense. So we are left with exactly *two* places that need explicit fsnotify_nameremove() call. Since both these callers already take care of calling fsnotify_create() I think that having explicit fsnotify_nameremove() calls there is clearer than the current state. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
