From 55e50223bf3e06abceaf68e2ad125458bb5f874f Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Thu, 13 Feb 2025 14:46:41 -0800 Subject: mm: introduce vma_iter_store_attached() to use with attached vmas vma_iter_store() functions can be used both when adding a new vma and when updating an existing one. However for existing ones we do not need to mark them attached as they are already marked that way. With vma->detached being a separate flag, double-marking a vmas as attached or detached is not an issue because the flag will simply be overwritten with the same value. However once we fold this flag into the refcount later in this series, re-attaching or re-detaching a vma becomes an issue since these operations will be incrementing/decrementing a refcount. Introduce vma_iter_store_new() and vma_iter_store_overwrite() to replace vma_iter_store() and avoid re-attaching a vma during vma update. Add assertions in vma_mark_attached()/vma_mark_detached() to catch invalid usage. Update vma tests to check for vma detached state correctness. Link: https://lkml.kernel.org/r/20250213224655.1680278-5-surenb@google.com Signed-off-by: Suren Baghdasaryan Tested-by: Shivank Garg Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com Reviewed-by: Liam R. Howlett Reviewed-by: Vlastimil Babka Cc: Christian Brauner Cc: David Hildenbrand Cc: David Howells Cc: Davidlohr Bueso Cc: Hugh Dickins Cc: Jann Horn Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Klara Modin Cc: Lokesh Gidra Cc: Lorenzo Stoakes Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko Cc: Minchan Kim Cc: Oleg Nesterov Cc: Pasha Tatashin Cc: "Paul E . McKenney" Cc: Peter Xu Cc: Peter Zijlstra (Intel) Cc: Shakeel Butt Cc: Sourav Panda Cc: Wei Yang Cc: Will Deacon Cc: Heiko Carstens Cc: Stephen Rothwell Signed-off-by: Andrew Morton --- include/linux/mm.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index d333d4070362..003c3e5c0a96 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -821,8 +821,19 @@ static inline void vma_assert_locked(struct vm_area_struct *vma) vma_assert_write_locked(vma); } +static inline void vma_assert_attached(struct vm_area_struct *vma) +{ + WARN_ON_ONCE(vma->detached); +} + +static inline void vma_assert_detached(struct vm_area_struct *vma) +{ + WARN_ON_ONCE(!vma->detached); +} + static inline void vma_mark_attached(struct vm_area_struct *vma) { + vma_assert_detached(vma); vma->detached = false; } @@ -830,6 +841,7 @@ static inline void vma_mark_detached(struct vm_area_struct *vma) { /* When detaching vma should be write-locked */ vma_assert_write_locked(vma); + vma_assert_attached(vma); vma->detached = true; } @@ -866,6 +878,8 @@ static inline void vma_end_read(struct vm_area_struct *vma) {} static inline void vma_start_write(struct vm_area_struct *vma) {} static inline void vma_assert_write_locked(struct vm_area_struct *vma) { mmap_assert_write_locked(vma->vm_mm); } +static inline void vma_assert_attached(struct vm_area_struct *vma) {} +static inline void vma_assert_detached(struct vm_area_struct *vma) {} static inline void vma_mark_attached(struct vm_area_struct *vma) {} static inline void vma_mark_detached(struct vm_area_struct *vma) {} -- cgit v1.2.3