From: Dmitry Safonov <dima@xxxxxxxxxx> Subject: vm_ops: rename .split() callback to .may_split() Rename the callback to reflect that it's not called *on* or *after* split, but rather some time before the splitting to check if it's possible. Link: https://lkml.kernel.org/r/20201013013416.390574-5-dima@xxxxxxxxxx Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/dax/device.c | 4 ++-- include/linux/mm.h | 3 ++- ipc/shm.c | 8 ++++---- mm/hugetlb.c | 2 +- mm/mmap.c | 4 ++-- 5 files changed, 11 insertions(+), 10 deletions(-) --- a/drivers/dax/device.c~vm_ops-rename-split-callback-to-may_split +++ a/drivers/dax/device.c @@ -256,7 +256,7 @@ static vm_fault_t dev_dax_fault(struct v return dev_dax_huge_fault(vmf, PE_SIZE_PTE); } -static int dev_dax_split(struct vm_area_struct *vma, unsigned long addr) +static int dev_dax_may_split(struct vm_area_struct *vma, unsigned long addr) { struct file *filp = vma->vm_file; struct dev_dax *dev_dax = filp->private_data; @@ -277,7 +277,7 @@ static unsigned long dev_dax_pagesize(st static const struct vm_operations_struct dax_vm_ops = { .fault = dev_dax_fault, .huge_fault = dev_dax_huge_fault, - .split = dev_dax_split, + .may_split = dev_dax_may_split, .pagesize = dev_dax_pagesize, }; --- a/include/linux/mm.h~vm_ops-rename-split-callback-to-may_split +++ a/include/linux/mm.h @@ -557,7 +557,8 @@ enum page_entry_size { struct vm_operations_struct { void (*open)(struct vm_area_struct * area); void (*close)(struct vm_area_struct * area); - int (*split)(struct vm_area_struct * area, unsigned long addr); + /* Called any time before splitting to check if it's allowed */ + int (*may_split)(struct vm_area_struct *area, unsigned long addr); int (*mremap)(struct vm_area_struct *area, unsigned long flags); vm_fault_t (*fault)(struct vm_fault *vmf); vm_fault_t (*huge_fault)(struct vm_fault *vmf, --- a/ipc/shm.c~vm_ops-rename-split-callback-to-may_split +++ a/ipc/shm.c @@ -434,13 +434,13 @@ static vm_fault_t shm_fault(struct vm_fa return sfd->vm_ops->fault(vmf); } -static int shm_split(struct vm_area_struct *vma, unsigned long addr) +static int shm_may_split(struct vm_area_struct *vma, unsigned long addr) { struct file *file = vma->vm_file; struct shm_file_data *sfd = shm_file_data(file); - if (sfd->vm_ops->split) - return sfd->vm_ops->split(vma, addr); + if (sfd->vm_ops->may_split) + return sfd->vm_ops->may_split(vma, addr); return 0; } @@ -582,7 +582,7 @@ static const struct vm_operations_struct .open = shm_open, /* callback for a new vm-area open */ .close = shm_close, /* callback for when the vm-area is released */ .fault = shm_fault, - .split = shm_split, + .may_split = shm_may_split, .pagesize = shm_pagesize, #if defined(CONFIG_NUMA) .set_policy = shm_set_policy, --- a/mm/hugetlb.c~vm_ops-rename-split-callback-to-may_split +++ a/mm/hugetlb.c @@ -3673,7 +3673,7 @@ const struct vm_operations_struct hugetl .fault = hugetlb_vm_op_fault, .open = hugetlb_vm_op_open, .close = hugetlb_vm_op_close, - .split = hugetlb_vm_op_split, + .may_split = hugetlb_vm_op_split, .pagesize = hugetlb_vm_op_pagesize, }; --- a/mm/mmap.c~vm_ops-rename-split-callback-to-may_split +++ a/mm/mmap.c @@ -2731,8 +2731,8 @@ int __split_vma(struct mm_struct *mm, st struct vm_area_struct *new; int err; - if (vma->vm_ops && vma->vm_ops->split) { - err = vma->vm_ops->split(vma, addr); + if (vma->vm_ops && vma->vm_ops->may_split) { + err = vma->vm_ops->may_split(vma, addr); if (err) return err; } _
