Split out "msync" logic into a file of its own. No actual code

changes.

mm/Makefile

@@ -14,6 +14,6 @@ export-objs := shmem.o filemap.o mempool.o page_alloc.o
 obj-y	 := memory.o mmap.o filemap.o mprotect.o mlock.o mremap.o \
 	    vmalloc.o slab.o bootmem.o swap.o vmscan.o page_io.o \
 	    page_alloc.o swap_state.o swapfile.o numa.o oom_kill.o \
-	    shmem.o highmem.o mempool.o
+	    shmem.o highmem.o mempool.o msync.o
 
 include $(TOPDIR)/Rules.make

mm/filemap.c

@@ -2082,107 +2082,6 @@ struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address
 	return NULL;
 }
 
-/* Called with mm->page_table_lock held to protect against other
- * threads/the swapper from ripping pte's out from under us.
- */
-static inline int filemap_sync_pte(pte_t *ptep, pmd_t *pmdp, struct vm_area_struct *vma,
-	unsigned long address, unsigned int flags)
-{
-	pte_t pte = *ptep;
-
-	if (pte_present(pte)) {
-		struct page *page = pte_page(pte);
-		if (VALID_PAGE(page) && !PageReserved(page) && ptep_test_and_clear_dirty(ptep)) {
-			flush_tlb_page(vma, address);
-			set_page_dirty(page);
-		}
-	}
-	return 0;
-}
-
-static inline int filemap_sync_pte_range(pmd_t * pmd,
-	unsigned long address, unsigned long end, 
-	struct vm_area_struct *vma, unsigned int flags)
-{
-	pte_t *pte;
-	int error;
-
-	if (pmd_none(*pmd))
-		return 0;
-	if (pmd_bad(*pmd)) {
-		pmd_ERROR(*pmd);
-		pmd_clear(pmd);
-		return 0;
-	}
-	pte = pte_offset_map(pmd, address);
-	if ((address & PMD_MASK) != (end & PMD_MASK))
-		end = (address & PMD_MASK) + PMD_SIZE;
-	error = 0;
-	do {
-		error |= filemap_sync_pte(pte, pmd, vma, address, flags);
-		address += PAGE_SIZE;
-		pte++;
-	} while (address && (address < end));
-
-	pte_unmap(pte - 1);
-
-	return error;
-}
-
-static inline int filemap_sync_pmd_range(pgd_t * pgd,
-	unsigned long address, unsigned long end, 
-	struct vm_area_struct *vma, unsigned int flags)
-{
-	pmd_t * pmd;
-	int error;
-
-	if (pgd_none(*pgd))
-		return 0;
-	if (pgd_bad(*pgd)) {
-		pgd_ERROR(*pgd);
-		pgd_clear(pgd);
-		return 0;
-	}
-	pmd = pmd_offset(pgd, address);
-	if ((address & PGDIR_MASK) != (end & PGDIR_MASK))
-		end = (address & PGDIR_MASK) + PGDIR_SIZE;
-	error = 0;
-	do {
-		error |= filemap_sync_pte_range(pmd, address, end, vma, flags);
-		address = (address + PMD_SIZE) & PMD_MASK;
-		pmd++;
-	} while (address && (address < end));
-	return error;
-}
-
-int filemap_sync(struct vm_area_struct * vma, unsigned long address,
-	size_t size, unsigned int flags)
-{
-	pgd_t * dir;
-	unsigned long end = address + size;
-	int error = 0;
-
-	/* Aquire the lock early; it may be possible to avoid dropping
-	 * and reaquiring it repeatedly.
-	 */
-	spin_lock(&vma->vm_mm->page_table_lock);
-
-	dir = pgd_offset(vma->vm_mm, address);
-	flush_cache_range(vma, address, end);
-	if (address >= end)
-		BUG();
-	do {
-		error |= filemap_sync_pmd_range(dir, address, end, vma, flags);
-		address = (address + PGDIR_SIZE) & PGDIR_MASK;
-		dir++;
-	} while (address && (address < end));
-	flush_tlb_range(vma, end - size, end);
-
-	spin_unlock(&vma->vm_mm->page_table_lock);
-
-	return error;
-}
-
 static struct vm_operations_struct generic_file_vm_ops = {
 	nopage:		filemap_nopage,
 };
@@ -2205,107 +2104,6 @@ int generic_file_mmap(struct file * file, struct vm_area_struct * vma)
 	return 0;
 }
 
-/*
- * The msync() system call.
- */
-
-/*
- * MS_SYNC syncs the entire file - including mappings.
- *
- * MS_ASYNC initiates writeout of just the dirty mapped data.
- * This provides no guarantee of file integrity - things like indirect
- * blocks may not have started writeout.  MS_ASYNC is primarily useful
- * where the application knows that it has finished with the data and
- * wishes to intelligently schedule its own I/O traffic.
- */
-static int msync_interval(struct vm_area_struct * vma,
-	unsigned long start, unsigned long end, int flags)
-{
-	int ret = 0;
-	struct file * file = vma->vm_file;
-
-	if (file && (vma->vm_flags & VM_SHARED)) {
-		ret = filemap_sync(vma, start, end-start, flags);
-
-		if (!ret && (flags & (MS_SYNC|MS_ASYNC))) {
-			struct inode * inode = file->f_dentry->d_inode;
-
-			down(&inode->i_sem);
-			ret = filemap_fdatasync(inode->i_mapping);
-			if (flags & MS_SYNC) {
-				int err;
-
-				if (file->f_op && file->f_op->fsync) {
-					err = file->f_op->fsync(file, file->f_dentry, 1);
-					if (err && !ret)
-						ret = err;
-				}
-				err = filemap_fdatawait(inode->i_mapping);
-				if (err && !ret)
-					ret = err;
-			}
-			up(&inode->i_sem);
-		}
-	}
-	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;
-
-	down_read(&current->mm->mmap_sem);
-	if (start & ~PAGE_MASK)
-		goto out;
-	len = (len + ~PAGE_MASK) & PAGE_MASK;
-	end = start + len;
-	if (end < start)
-		goto out;
-	if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
-		goto out;
-	error = 0;
-	if (end == start)
-		goto out;
-	/*
-	 * If the interval [start,end) covers some unmapped address ranges,
-	 * just ignore them, but return -EFAULT at the end.
-	 */
-	vma = find_vma(current->mm, start);
-	unmapped_error = 0;
-	for (;;) {
-		/* Still start < end. */
-		error = -EFAULT;
-		if (!vma)
-			goto out;
-		/* Here start < vma->vm_end. */
-		if (start < vma->vm_start) {
-			unmapped_error = -EFAULT;
-			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);
-	return error;
-}
-
 static inline void setup_read_behavior(struct vm_area_struct * vma,
 	int behavior)
 {

mm/msync.c

+/*
+ *	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 <asm/pgtable.h>
+#include <asm/pgalloc.h>
+
+/*
+ * Called with mm->page_table_lock held to protect against other
+ * threads/the swapper from ripping pte's out from under us.
+ */
+static inline int filemap_sync_pte(pte_t *ptep, pmd_t *pmdp, struct vm_area_struct *vma,
+	unsigned long address, unsigned int flags)
+{
+	pte_t pte = *ptep;
+
+	if (pte_present(pte)) {
+		struct page *page = pte_page(pte);
+		if (VALID_PAGE(page) && !PageReserved(page) && ptep_test_and_clear_dirty(ptep)) {
+			flush_tlb_page(vma, address);
+			set_page_dirty(page);
+		}
+	}
+	return 0;
+}
+
+static inline int filemap_sync_pte_range(pmd_t * pmd,
+	unsigned long address, unsigned long end, 
+	struct vm_area_struct *vma, unsigned int flags)
+{
+	pte_t *pte;
+	int error;
+
+	if (pmd_none(*pmd))
+		return 0;
+	if (pmd_bad(*pmd)) {
+		pmd_ERROR(*pmd);
+		pmd_clear(pmd);
+		return 0;
+	}
+	pte = pte_offset_map(pmd, address);
+	if ((address & PMD_MASK) != (end & PMD_MASK))
+		end = (address & PMD_MASK) + PMD_SIZE;
+	error = 0;
+	do {
+		error |= filemap_sync_pte(pte, pmd, vma, address, flags);
+		address += PAGE_SIZE;
+		pte++;
+	} while (address && (address < end));
+
+	pte_unmap(pte - 1);
+
+	return error;
+}
+
+static inline int filemap_sync_pmd_range(pgd_t * pgd,
+	unsigned long address, unsigned long end, 
+	struct vm_area_struct *vma, unsigned int flags)
+{
+	pmd_t * pmd;
+	int error;
+
+	if (pgd_none(*pgd))
+		return 0;
+	if (pgd_bad(*pgd)) {
+		pgd_ERROR(*pgd);
+		pgd_clear(pgd);
+		return 0;
+	}
+	pmd = pmd_offset(pgd, address);
+	if ((address & PGDIR_MASK) != (end & PGDIR_MASK))
+		end = (address & PGDIR_MASK) + PGDIR_SIZE;
+	error = 0;
+	do {
+		error |= filemap_sync_pte_range(pmd, address, end, vma, flags);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address && (address < end));
+	return error;
+}
+
+int filemap_sync(struct vm_area_struct * vma, unsigned long address,
+	size_t size, unsigned int flags)
+{
+	pgd_t * dir;
+	unsigned long end = address + size;
+	int error = 0;
+
+	/* Aquire the lock early; it may be possible to avoid dropping
+	 * and reaquiring it repeatedly.
+	 */
+	spin_lock(&vma->vm_mm->page_table_lock);
+
+	dir = pgd_offset(vma->vm_mm, address);
+	flush_cache_range(vma, address, end);
+	if (address >= end)
+		BUG();
+	do {
+		error |= filemap_sync_pmd_range(dir, address, end, vma, flags);
+		address = (address + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	} while (address && (address < end));
+	flush_tlb_range(vma, end - size, end);
+
+	spin_unlock(&vma->vm_mm->page_table_lock);
+
+	return error;
+}
+
+/*
+ * MS_SYNC syncs the entire file - including mappings.
+ *
+ * MS_ASYNC initiates writeout of just the dirty mapped data.
+ * This provides no guarantee of file integrity - things like indirect
+ * blocks may not have started writeout.  MS_ASYNC is primarily useful
+ * where the application knows that it has finished with the data and
+ * wishes to intelligently schedule its own I/O traffic.
+ */
+static int msync_interval(struct vm_area_struct * vma,
+	unsigned long start, unsigned long end, int flags)
+{
+	int ret = 0;
+	struct file * file = vma->vm_file;
+
+	if (file && (vma->vm_flags & VM_SHARED)) {
+		ret = filemap_sync(vma, start, end-start, flags);
+
+		if (!ret && (flags & (MS_SYNC|MS_ASYNC))) {
+			struct inode * inode = file->f_dentry->d_inode;
+
+			down(&inode->i_sem);
+			ret = filemap_fdatasync(inode->i_mapping);
+			if (flags & MS_SYNC) {
+				int err;
+
+				if (file->f_op && file->f_op->fsync) {
+					err = file->f_op->fsync(file, file->f_dentry, 1);
+					if (err && !ret)
+						ret = err;
+				}
+				err = filemap_fdatawait(inode->i_mapping);
+				if (err && !ret)
+					ret = err;
+			}
+			up(&inode->i_sem);
+		}
+	}
+	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;
+
+	down_read(&current->mm->mmap_sem);
+	if (start & ~PAGE_MASK)
+		goto out;
+	len = (len + ~PAGE_MASK) & PAGE_MASK;
+	end = start + len;
+	if (end < start)
+		goto out;
+	if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
+		goto out;
+	error = 0;
+	if (end == start)
+		goto out;
+	/*
+	 * If the interval [start,end) covers some unmapped address ranges,
+	 * just ignore them, but return -EFAULT at the end.
+	 */
+	vma = find_vma(current->mm, start);
+	unmapped_error = 0;
+	for (;;) {
+		/* Still start < end. */
+		error = -EFAULT;
+		if (!vma)
+			goto out;
+		/* Here start < vma->vm_end. */
+		if (start < vma->vm_start) {
+			unmapped_error = -EFAULT;
+			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);
+	return error;
+}
+
+