| Message ID | 20220503221728.185449-3-david@fromorbit.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | xfs: intent whiteouts | expand |
On Wed, 2022-05-04 at 08:17 +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > Ever since we added shadown format buffers to the log items, log > items need to handle the item being released with shadow buffers > attached. Due to the fact this requirement was added at the same > time we added new rmap/reflink intents, we missed the cleanup of > those items. > > In theory, this means shadow buffers can be leaked in a very small > window when a shutdown is initiated. Testing with KASAN shows this > leak does not happen in practice - we haven't identified a single > leak in several years of shutdown testing since ~v4.8 kernels. > > However, the intent whiteout cleanup mechanism results in every > cancelled intent in exactly the same state as this tiny race window > creates and so if intents down clean up shadow buffers on final > release we will leak the shadow buffer for just about every intent > we create. > > Hence we start with this patch to close this condition off and > ensure that when whiteouts start to be used we don't leak lots of > memory. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> Ok, looks good to me Reviewed-by: Allison Henderson <allison.henderson@oracle.com> > --- > fs/xfs/xfs_bmap_item.c | 2 ++ > fs/xfs/xfs_icreate_item.c | 1 + > fs/xfs/xfs_refcount_item.c | 2 ++ > fs/xfs/xfs_rmap_item.c | 2 ++ > 4 files changed, 7 insertions(+) > > diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c > index 593ac29cffc7..2c8b686e2a11 100644 > --- a/fs/xfs/xfs_bmap_item.c > +++ b/fs/xfs/xfs_bmap_item.c > @@ -39,6 +39,7 @@ STATIC void > xfs_bui_item_free( > struct xfs_bui_log_item *buip) > { > + kmem_free(buip->bui_item.li_lv_shadow); > kmem_cache_free(xfs_bui_cache, buip); > } > > @@ -198,6 +199,7 @@ xfs_bud_item_release( > struct xfs_bud_log_item *budp = BUD_ITEM(lip); > > xfs_bui_release(budp->bud_buip); > + kmem_free(budp->bud_item.li_lv_shadow); > kmem_cache_free(xfs_bud_cache, budp); > } > > diff --git a/fs/xfs/xfs_icreate_item.c b/fs/xfs/xfs_icreate_item.c > index 508e184e3b8f..b05314d48176 100644 > --- a/fs/xfs/xfs_icreate_item.c > +++ b/fs/xfs/xfs_icreate_item.c > @@ -63,6 +63,7 @@ STATIC void > xfs_icreate_item_release( > struct xfs_log_item *lip) > { > + kmem_free(ICR_ITEM(lip)->ic_item.li_lv_shadow); > kmem_cache_free(xfs_icreate_cache, ICR_ITEM(lip)); > } > > diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c > index 0d868c93144d..10474fe389e1 100644 > --- a/fs/xfs/xfs_refcount_item.c > +++ b/fs/xfs/xfs_refcount_item.c > @@ -35,6 +35,7 @@ STATIC void > xfs_cui_item_free( > struct xfs_cui_log_item *cuip) > { > + kmem_free(cuip->cui_item.li_lv_shadow); > if (cuip->cui_format.cui_nextents > XFS_CUI_MAX_FAST_EXTENTS) > kmem_free(cuip); > else > @@ -204,6 +205,7 @@ xfs_cud_item_release( > struct xfs_cud_log_item *cudp = CUD_ITEM(lip); > > xfs_cui_release(cudp->cud_cuip); > + kmem_free(cudp->cud_item.li_lv_shadow); > kmem_cache_free(xfs_cud_cache, cudp); > } > > diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c > index a22b2d19ef91..6c0b56ebdbe1 100644 > --- a/fs/xfs/xfs_rmap_item.c > +++ b/fs/xfs/xfs_rmap_item.c > @@ -35,6 +35,7 @@ STATIC void > xfs_rui_item_free( > struct xfs_rui_log_item *ruip) > { > + kmem_free(ruip->rui_item.li_lv_shadow); > if (ruip->rui_format.rui_nextents > XFS_RUI_MAX_FAST_EXTENTS) > kmem_free(ruip); > else > @@ -227,6 +228,7 @@ xfs_rud_item_release( > struct xfs_rud_log_item *rudp = RUD_ITEM(lip); > > xfs_rui_release(rudp->rud_ruip); > + kmem_free(rudp->rud_item.li_lv_shadow); > kmem_cache_free(xfs_rud_cache, rudp); > } >
On Wed, May 04, 2022 at 08:17:20AM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > Ever since we added shadown format buffers to the log items, log > items need to handle the item being released with shadow buffers > attached. Due to the fact this requirement was added at the same > time we added new rmap/reflink intents, we missed the cleanup of > those items. > > In theory, this means shadow buffers can be leaked in a very small > window when a shutdown is initiated. Testing with KASAN shows this > leak does not happen in practice - we haven't identified a single > leak in several years of shutdown testing since ~v4.8 kernels. > > However, the intent whiteout cleanup mechanism results in every > cancelled intent in exactly the same state as this tiny race window > creates and so if intents down clean up shadow buffers on final > release we will leak the shadow buffer for just about every intent > we create. > > Hence we start with this patch to close this condition off and > ensure that when whiteouts start to be used we don't leak lots of > memory. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> > --- > fs/xfs/xfs_bmap_item.c | 2 ++ > fs/xfs/xfs_icreate_item.c | 1 + > fs/xfs/xfs_refcount_item.c | 2 ++ > fs/xfs/xfs_rmap_item.c | 2 ++ > 4 files changed, 7 insertions(+) > > diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c > index 593ac29cffc7..2c8b686e2a11 100644 > --- a/fs/xfs/xfs_bmap_item.c > +++ b/fs/xfs/xfs_bmap_item.c > @@ -39,6 +39,7 @@ STATIC void > xfs_bui_item_free( > struct xfs_bui_log_item *buip) > { > + kmem_free(buip->bui_item.li_lv_shadow); > kmem_cache_free(xfs_bui_cache, buip); > } > > @@ -198,6 +199,7 @@ xfs_bud_item_release( > struct xfs_bud_log_item *budp = BUD_ITEM(lip); > > xfs_bui_release(budp->bud_buip); > + kmem_free(budp->bud_item.li_lv_shadow); > kmem_cache_free(xfs_bud_cache, budp); > } > > diff --git a/fs/xfs/xfs_icreate_item.c b/fs/xfs/xfs_icreate_item.c > index 508e184e3b8f..b05314d48176 100644 > --- a/fs/xfs/xfs_icreate_item.c > +++ b/fs/xfs/xfs_icreate_item.c > @@ -63,6 +63,7 @@ STATIC void > xfs_icreate_item_release( > struct xfs_log_item *lip) > { > + kmem_free(ICR_ITEM(lip)->ic_item.li_lv_shadow); Oh hey, I missed one. Good catch! Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > kmem_cache_free(xfs_icreate_cache, ICR_ITEM(lip)); > } > > diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c > index 0d868c93144d..10474fe389e1 100644 > --- a/fs/xfs/xfs_refcount_item.c > +++ b/fs/xfs/xfs_refcount_item.c > @@ -35,6 +35,7 @@ STATIC void > xfs_cui_item_free( > struct xfs_cui_log_item *cuip) > { > + kmem_free(cuip->cui_item.li_lv_shadow); > if (cuip->cui_format.cui_nextents > XFS_CUI_MAX_FAST_EXTENTS) > kmem_free(cuip); > else > @@ -204,6 +205,7 @@ xfs_cud_item_release( > struct xfs_cud_log_item *cudp = CUD_ITEM(lip); > > xfs_cui_release(cudp->cud_cuip); > + kmem_free(cudp->cud_item.li_lv_shadow); > kmem_cache_free(xfs_cud_cache, cudp); > } > > diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c > index a22b2d19ef91..6c0b56ebdbe1 100644 > --- a/fs/xfs/xfs_rmap_item.c > +++ b/fs/xfs/xfs_rmap_item.c > @@ -35,6 +35,7 @@ STATIC void > xfs_rui_item_free( > struct xfs_rui_log_item *ruip) > { > + kmem_free(ruip->rui_item.li_lv_shadow); > if (ruip->rui_format.rui_nextents > XFS_RUI_MAX_FAST_EXTENTS) > kmem_free(ruip); > else > @@ -227,6 +228,7 @@ xfs_rud_item_release( > struct xfs_rud_log_item *rudp = RUD_ITEM(lip); > > xfs_rui_release(rudp->rud_ruip); > + kmem_free(rudp->rud_item.li_lv_shadow); > kmem_cache_free(xfs_rud_cache, rudp); > } > > -- > 2.35.1 >
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c index 593ac29cffc7..2c8b686e2a11 100644 --- a/fs/xfs/xfs_bmap_item.c +++ b/fs/xfs/xfs_bmap_item.c @@ -39,6 +39,7 @@ STATIC void xfs_bui_item_free( struct xfs_bui_log_item *buip) { + kmem_free(buip->bui_item.li_lv_shadow); kmem_cache_free(xfs_bui_cache, buip); } @@ -198,6 +199,7 @@ xfs_bud_item_release( struct xfs_bud_log_item *budp = BUD_ITEM(lip); xfs_bui_release(budp->bud_buip); + kmem_free(budp->bud_item.li_lv_shadow); kmem_cache_free(xfs_bud_cache, budp); } diff --git a/fs/xfs/xfs_icreate_item.c b/fs/xfs/xfs_icreate_item.c index 508e184e3b8f..b05314d48176 100644 --- a/fs/xfs/xfs_icreate_item.c +++ b/fs/xfs/xfs_icreate_item.c @@ -63,6 +63,7 @@ STATIC void xfs_icreate_item_release( struct xfs_log_item *lip) { + kmem_free(ICR_ITEM(lip)->ic_item.li_lv_shadow); kmem_cache_free(xfs_icreate_cache, ICR_ITEM(lip)); } diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c index 0d868c93144d..10474fe389e1 100644 --- a/fs/xfs/xfs_refcount_item.c +++ b/fs/xfs/xfs_refcount_item.c @@ -35,6 +35,7 @@ STATIC void xfs_cui_item_free( struct xfs_cui_log_item *cuip) { + kmem_free(cuip->cui_item.li_lv_shadow); if (cuip->cui_format.cui_nextents > XFS_CUI_MAX_FAST_EXTENTS) kmem_free(cuip); else @@ -204,6 +205,7 @@ xfs_cud_item_release( struct xfs_cud_log_item *cudp = CUD_ITEM(lip); xfs_cui_release(cudp->cud_cuip); + kmem_free(cudp->cud_item.li_lv_shadow); kmem_cache_free(xfs_cud_cache, cudp); } diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c index a22b2d19ef91..6c0b56ebdbe1 100644 --- a/fs/xfs/xfs_rmap_item.c +++ b/fs/xfs/xfs_rmap_item.c @@ -35,6 +35,7 @@ STATIC void xfs_rui_item_free( struct xfs_rui_log_item *ruip) { + kmem_free(ruip->rui_item.li_lv_shadow); if (ruip->rui_format.rui_nextents > XFS_RUI_MAX_FAST_EXTENTS) kmem_free(ruip); else @@ -227,6 +228,7 @@ xfs_rud_item_release( struct xfs_rud_log_item *rudp = RUD_ITEM(lip); xfs_rui_release(rudp->rud_ruip); + kmem_free(rudp->rud_item.li_lv_shadow); kmem_cache_free(xfs_rud_cache, rudp); }