Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 236 insertions, 0 deletions

diff --git a/mm/msync.c b/mm/msync.c
new file mode 100644
index 000000000000..090f426bca7d
--- /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(&current->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(&current->mm->mmap_sem);
+        current->flags &= ~PF_SYNCWRITE;
+        return error;
+}