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@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 25e0b84..5da2980 100644 (file)
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -256,7 +256,7 @@ static vm_fault_t dev_dax_fault(struct vm_fault *vmf)
        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(struct vm_area_struct *vma)
 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,
 };
 

diff --git a/include/linux/mm.h b/include/linux/mm.h
index dacc889..5d188b8 100644 (file)
--- a/include/linux/mm.h
+++ b/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,

diff --git a/ipc/shm.c b/ipc/shm.c
index e25c7c6..febd88d 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -434,13 +434,13 @@ static vm_fault_t shm_fault(struct vm_fault *vmf)
        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 shm_vm_ops = {
        .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,

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d029d93..4b809cc 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3673,7 +3673,7 @@ const struct vm_operations_struct hugetlb_vm_ops = {
        .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,
 };
 

diff --git a/mm/mmap.c b/mm/mmap.c
index 8950c20..886de79 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2731,8 +2731,8 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
        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;
        }