Messages in this thread | | | Date | Tue, 24 Nov 2015 19:36:29 +0100 | From | Matias <> | Subject | Re: [PATCH] lightnvm: missing nvm_lock acquire |
| |
On 11/24/2015 04:24 PM, Wenwei Tao wrote: > To avoid race conditions, traverse dev, media manager, > and targeet lists and also register, unregister entries > to/from them, should be always under the nvm_lock control. > > Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com> > --- > drivers/lightnvm/core.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c > index f659e60..39aec3a 100644 > --- a/drivers/lightnvm/core.c > +++ b/drivers/lightnvm/core.c > @@ -333,19 +333,19 @@ EXPORT_SYMBOL(nvm_register); > > void nvm_unregister(char *disk_name) > { > + down_write(&nvm_lock); > struct nvm_dev *dev = nvm_find_nvm_dev(disk_name);
In nvm_find_nvm_dev, can we instead replace it with list_for_each_entry_safe. Then we are sure that we won't hit a missing element, and will make the other cases significantly cleaner.
> > if (!dev) { > pr_err("nvm: could not find device %s to unregister\n", > disk_name); > + up_write(&nvm_lock); > return; > } > > - nvm_exit(dev); > - > - down_write(&nvm_lock); > list_del(&dev->devices); > up_write(&nvm_lock); > + nvm_exit(dev); > } > EXPORT_SYMBOL(nvm_unregister); > > @@ -365,12 +365,15 @@ static int nvm_create_target(struct nvm_dev *dev, > void *targetdata; > int ret = 0; > > + down_write(&nvm_lock); > if (!dev->mt) { > /* register with device with a supported NVM manager */ > list_for_each_entry(mt, &nvm_mgrs, list) {
Same with this one?
| |