It's useful to be able to determine the size of a VMA descriptor range used on f_op->mmap_prepare, expressed both in bytes and pages, so add helpers for both and update code that could make use of it to do so. Signed-off-by: Lorenzo Stoakes --- fs/ntfs3/file.c | 2 +- include/linux/mm.h | 10 ++++++++++ mm/secretmem.c | 2 +- 3 files changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c index c1ece707b195..86eb88f62714 100644 --- a/fs/ntfs3/file.c +++ b/fs/ntfs3/file.c @@ -304,7 +304,7 @@ static int ntfs_file_mmap_prepare(struct vm_area_desc *desc) if (rw) { u64 to = min_t(loff_t, i_size_read(inode), - from + desc->end - desc->start); + from + vma_desc_size(desc)); if (is_sparsed(ni)) { /* Allocate clusters for rw map. */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 892fe5dbf9de..0b97589aec6d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3572,6 +3572,16 @@ static inline unsigned long vma_pages(const struct vm_area_struct *vma) return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; } +static inline unsigned long vma_desc_size(struct vm_area_desc *desc) +{ + return desc->end - desc->start; +} + +static inline unsigned long vma_desc_pages(struct vm_area_desc *desc) +{ + return vma_desc_size(desc) >> PAGE_SHIFT; +} + /* Look up the first VMA which exactly match the interval vm_start ... vm_end */ static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm, unsigned long vm_start, unsigned long vm_end) diff --git a/mm/secretmem.c b/mm/secretmem.c index 60137305bc20..62066ddb1e9c 100644 --- a/mm/secretmem.c +++ b/mm/secretmem.c @@ -120,7 +120,7 @@ static int secretmem_release(struct inode *inode, struct file *file) static int secretmem_mmap_prepare(struct vm_area_desc *desc) { - const unsigned long len = desc->end - desc->start; + const unsigned long len = vma_desc_size(desc); if ((desc->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0) return -EINVAL; -- 2.51.0