[Cocci] [bug] exists do not work if file group is too big (>49)

[jglisse@redhat.com (Jerome Glisse)]

When operating on too many files the exists keyword no longer work. For
instance:

@exists@
expression E1;
@@
set_page_dirty(
+NULL,
E1)

Using linux kernel as playground and looking at at fs/f2fs/gc.c where
there is set_page_dirty() calls in nested blocks.

Works:

spatch --no-includes --sp-file test.spatch arch/powerpc/kvm/book3s_64_mmu_radix.c arch/powerpc/kvm/e500_mmu.c arch/s390/kvm/interrupt.c arch/x86/kvm/svm.c block/bio.c drivers/block/zram/zram_drv.c drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c drivers/gpu/drm/drm_gem.c drivers/gpu/drm/exynos/exynos_drm_g2d.c drivers/gpu/drm/i915/i915_gem.c drivers/gpu/drm/i915/i915_gem_fence_reg.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/gpu/drm/radeon/radeon_ttm.c drivers/gpu/drm/ttm/ttm_tt.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/hw/hfi1/user_pages.c drivers/infiniband/hw/qib/qib_user_pages.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/media/common/videobuf2/videobuf2-dma-contig.c drivers/media/common/videobuf2/videobuf2-dma-sg.c drivers/media/common/videobuf2/videobuf2-vmalloc.c drivers/misc/genwqe/card_utils.c drivers/misc/vmw_vmci/vmci_queue_pair.c drivers/mtd/devices/block2mtd.c drivers/platform/goldfish/goldfish_pipe.c drivers/sbus/char/oradax.c drivers/staging/lustre/lustre/llite/rw26.c drivers/staging/lustre/lustre/llite/vvp_io.c drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c drivers/vhost/vhost.c drivers/video/fbdev/core/fb_defio.c fs/9p/vfs_addr.c fs/afs/dir.c fs/afs/file.c --include fs/afs/internal.h fs/afs/write.c fs/aio.c fs/block_dev.c fs/btrfs/disk-io.c fs/btrfs/extent_io.c fs/btrfs/file.c fs/btrfs/inode.c fs/btrfs/ioctl.c fs/btrfs/relocation.c fs/buffer.c fs/ceph/addr.c fs/f2fs/gc.c > toto


Don't works:

spatch --no-includes --sp-file test.spatch arch/powerpc/kvm/book3s_64_mmu_radix.c arch/powerpc/kvm/e500_mmu.c arch/s390/kvm/interrupt.c arch/x86/kvm/svm.c block/bio.c drivers/block/zram/zram_drv.c drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c drivers/gpu/drm/drm_gem.c drivers/gpu/drm/exynos/exynos_drm_g2d.c drivers/gpu/drm/i915/i915_gem.c drivers/gpu/drm/i915/i915_gem_fence_reg.c drivers/gpu/drm/i915/i915_gem_userptr.c drivers/gpu/drm/radeon/radeon_ttm.c drivers/gpu/drm/ttm/ttm_tt.c drivers/infiniband/core/umem.c drivers/infiniband/core/umem_odp.c drivers/infiniband/hw/hfi1/user_pages.c drivers/infiniband/hw/qib/qib_user_pages.c drivers/infiniband/hw/usnic/usnic_uiom.c drivers/media/common/videobuf2/videobuf2-dma-contig.c drivers/media/common/videobuf2/videobuf2-dma-sg.c drivers/media/common/videobuf2/videobuf2-vmalloc.c drivers/misc/genwqe/card_utils.c drivers/misc/vmw_vmci/vmci_queue_pair.c drivers/mtd/devices/block2mtd.c drivers/platform/goldfish/goldfish_pipe.c drivers/sbus/char/oradax.c drivers/staging/lustre/lustre/llite/rw26.c drivers/staging/lustre/lustre/llite/vvp_io.c drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c drivers/vhost/vhost.c drivers/video/fbdev/core/fb_defio.c fs/9p/vfs_addr.c fs/afs/dir.c fs/afs/file.c --include fs/afs/internal.h fs/afs/write.c fs/aio.c fs/block_dev.c fs/btrfs/disk-io.c fs/btrfs/extent_io.c fs/btrfs/file.c fs/btrfs/inode.c fs/btrfs/ioctl.c fs/btrfs/relocation.c fs/buffer.c fs/ceph/addr.c fs/cifs/cifssmb.c fs/f2fs/gc.c > toto


Exact same command line except the latter have 49 files before
fs/f2fs/gc.c while the former has 48 (and it works then). Note
that it seems that running the script multiple times even when
they are too many files will eventualy work.

Cheers,
J?r?me