> Il giorno 1 apr 2022, alle ore 12:27, Jan Kara <jack@xxxxxxx> ha scritto: > > Hello, > > here is the seventh version of my patches to fix use-after-free issues in BFQ > when processes with merged queues get moved to different cgroups. Kuai has > confirmed that patches now fix all the issues his reproducer was able to > trigger so I've just added some tags, codewise this is the same as v6. Paolo, > can you please check whether the patches look good to you so that Jens can > merge them? I think this is not needed any longer :) At any rate, your patches do fix an evident problem, in a correct way. Thank you, Paolo > Thanks! > > Changes since v6: > * Added some Tested-by, Fixes, and CC tags > > Changes since v5: > * Added handling of situation when bio is submitted for a cgroup that has > already went through bfq_pd_offline() > * Convert bfq to avoid using deprecated __bio_blkcg() and thus fix possible > races when returned cgroup can change while bfq is working with a request > > Changes since v4: > * Even more aggressive splitting of merged bfq queues to avoid problems with > long merge chains. > > Changes since v3: > * Changed handling of bfq group move to handle the case when target of the > merge has moved. > > Changes since v2: > * Improved handling of bfq queue splitting on move between cgroups > * Removed broken change to bfq_put_cooperator() > > Changes since v1: > * Added fix for bfq_put_cooperator() > * Added fix to handle move between cgroups in bfq_merge_bio() > > Honza > Previous versions: > Link: http://lore.kernel.org/r/20211223171425.3551-1-jack@xxxxxxx # v1 > Link: http://lore.kernel.org/r/20220105143037.20542-1-jack@xxxxxxx # v2 > Link: http://lore.kernel.org/r/20220112113529.6355-1-jack@xxxxxxx # v3 > Link: http://lore.kernel.org/r/20220114164215.28972-1-jack@xxxxxxx # v4 > Link: http://lore.kernel.org/r/20220121105503.14069-1-jack@xxxxxxx # v5 > Link: http://lore.kernel.org/r/20220330123438.32719-1-jack@xxxxxxx # v6
