Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/mm/msync.c b/mm/msync.c
new file mode 100644
index 0000000..090f426
--- /dev/null
+++ b/mm/msync.c
@@ -0,0 +1,236 @@
+/*
+ * linux/mm/msync.c
+ *
+ * Copyright (C) 1994-1999 Linus Torvalds
+ */
+
+/*
+ * The msync() system call.
+ */
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/hugetlb.h>
+#include <linux/syscalls.h>
+
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+
+/*
+ * Called with mm->page_table_lock held to protect against other
+ * threads/the swapper from ripping pte's out from under us.
+ */
+
+static void sync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end)
+{
+ pte_t *pte;
+
+ pte = pte_offset_map(pmd, addr);
+ do {
+ unsigned long pfn;
+ struct page *page;
+
+ if (!pte_present(*pte))
+ continue;
+ pfn = pte_pfn(*pte);
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+ if (PageReserved(page))
+ continue;
+
+ if (ptep_clear_flush_dirty(vma, addr, pte) ||
+ page_test_and_clear_dirty(page))
+ set_page_dirty(page);
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ pte_unmap(pte - 1);
+}
+
+static inline void sync_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ sync_pte_range(vma, pmd, addr, next);
+ } while (pmd++, addr = next, addr != end);
+}
+
+static inline void sync_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ sync_pmd_range(vma, pud, addr, next);
+ } while (pud++, addr = next, addr != end);
+}
+
+static void sync_page_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ unsigned long next;
+
+ /* For hugepages we can't go walking the page table normally,
+ * but that's ok, hugetlbfs is memory based, so we don't need
+ * to do anything more on an msync() */
+ if (is_vm_hugetlb_page(vma))
+ return;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset(mm, addr);
+ flush_cache_range(vma, addr, end);
+ spin_lock(&mm->page_table_lock);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ sync_pud_range(vma, pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+ spin_unlock(&mm->page_table_lock);
+}
+
+#ifdef CONFIG_PREEMPT
+static inline void filemap_sync(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ const size_t chunk = 64 * 1024; /* bytes */
+ unsigned long next;
+
+ do {
+ next = addr + chunk;
+ if (next > end || next < addr)
+ next = end;
+ sync_page_range(vma, addr, next);
+ cond_resched();
+ } while (addr = next, addr != end);
+}
+#else
+static inline void filemap_sync(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ sync_page_range(vma, addr, end);
+}
+#endif
+
+/*
+ * MS_SYNC syncs the entire file - including mappings.
+ *
+ * MS_ASYNC does not start I/O (it used to, up to 2.5.67). Instead, it just
+ * marks the relevant pages dirty. The application may now run fsync() to
+ * write out the dirty pages and wait on the writeout and check the result.
+ * Or the application may run fadvise(FADV_DONTNEED) against the fd to start
+ * async writeout immediately.
+ * So my _not_ starting I/O in MS_ASYNC we provide complete flexibility to
+ * applications.
+ */
+static int msync_interval(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end, int flags)
+{
+ int ret = 0;
+ struct file *file = vma->vm_file;
+
+ if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED))
+ return -EBUSY;
+
+ if (file && (vma->vm_flags & VM_SHARED)) {
+ filemap_sync(vma, addr, end);
+
+ if (flags & MS_SYNC) {
+ struct address_space *mapping = file->f_mapping;
+ int err;
+
+ ret = filemap_fdatawrite(mapping);
+ if (file->f_op && file->f_op->fsync) {
+ /*
+ * We don't take i_sem here because mmap_sem
+ * is already held.
+ */
+ err = file->f_op->fsync(file,file->f_dentry,1);
+ if (err && !ret)
+ ret = err;
+ }
+ err = filemap_fdatawait(mapping);
+ if (!ret)
+ ret = err;
+ }
+ }
+ return ret;
+}
+
+asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
+{
+ unsigned long end;
+ struct vm_area_struct *vma;
+ int unmapped_error, error = -EINVAL;
+
+ if (flags & MS_SYNC)
+ current->flags |= PF_SYNCWRITE;
+
+ down_read(¤t->mm->mmap_sem);
+ if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
+ goto out;
+ if (start & ~PAGE_MASK)
+ goto out;
+ if ((flags & MS_ASYNC) && (flags & MS_SYNC))
+ goto out;
+ error = -ENOMEM;
+ len = (len + ~PAGE_MASK) & PAGE_MASK;
+ end = start + len;
+ if (end < start)
+ goto out;
+ error = 0;
+ if (end == start)
+ goto out;
+ /*
+ * If the interval [start,end) covers some unmapped address ranges,
+ * just ignore them, but return -ENOMEM at the end.
+ */
+ vma = find_vma(current->mm, start);
+ unmapped_error = 0;
+ for (;;) {
+ /* Still start < end. */
+ error = -ENOMEM;
+ if (!vma)
+ goto out;
+ /* Here start < vma->vm_end. */
+ if (start < vma->vm_start) {
+ unmapped_error = -ENOMEM;
+ start = vma->vm_start;
+ }
+ /* Here vma->vm_start <= start < vma->vm_end. */
+ if (end <= vma->vm_end) {
+ if (start < end) {
+ error = msync_interval(vma, start, end, flags);
+ if (error)
+ goto out;
+ }
+ error = unmapped_error;
+ goto out;
+ }
+ /* Here vma->vm_start <= start < vma->vm_end < end. */
+ error = msync_interval(vma, start, vma->vm_end, flags);
+ if (error)
+ goto out;
+ start = vma->vm_end;
+ vma = vma->vm_next;
+ }
+out:
+ up_read(¤t->mm->mmap_sem);
+ current->flags &= ~PF_SYNCWRITE;
+ return error;
+}