3 files changed, 40 insertions, 11 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index a4a5260b0279..fa5ca304148e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1712,8 +1712,35 @@ page_not_uptodate:
 }
 EXPORT_SYMBOL(filemap_fault);
 
+int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        struct page *page = vmf->page;
+        struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+        int ret = VM_FAULT_LOCKED;
+
+        sb_start_pagefault(inode->i_sb);
+        file_update_time(vma->vm_file);
+        lock_page(page);
+        if (page->mapping != inode->i_mapping) {
+                unlock_page(page);
+                ret = VM_FAULT_NOPAGE;
+                goto out;
+        }
+        /*
+         * We mark the page dirty already here so that when freeze is in
+         * progress, we are guaranteed that writeback during freezing will
+         * see the dirty page and writeprotect it again.
+         */
+        set_page_dirty(page);
+out:
+        sb_end_pagefault(inode->i_sb);
+        return ret;
+}
+EXPORT_SYMBOL(filemap_page_mkwrite);
+
 const struct vm_operations_struct generic_file_vm_ops = {
         .fault          = filemap_fault,
+        .page_mkwrite   = filemap_page_mkwrite,
 };
 
 /* This is used for a general mmap of a disk file */
@@ -2407,8 +2434,6 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         count = ocount;
         pos = *ppos;
 
-        vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
-
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = mapping->backing_dev_info;
         written = 0;
@@ -2507,6 +2532,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
         BUG_ON(iocb->ki_pos != pos);
 
+        sb_start_write(inode->i_sb);
         mutex_lock(&inode->i_mutex);
         blk_start_plug(&plug);
         ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
@@ -2520,6 +2546,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
                         ret = err;
         }
         blk_finish_plug(&plug);
+        sb_end_write(inode->i_sb);
         return ret;
 }
 EXPORT_SYMBOL(generic_file_aio_write);
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 213ca1f53409..13e013b1270c 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -304,6 +304,7 @@ out:
 
 static const struct vm_operations_struct xip_file_vm_ops = {
         .fault  = xip_file_fault,
+        .page_mkwrite   = filemap_page_mkwrite,
 };
 
 int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
@@ -401,6 +402,8 @@ xip_file_write(struct file *filp, const char __user *buf, size_t len,
         loff_t pos;
         ssize_t ret;
 
+        sb_start_write(inode->i_sb);
+
         mutex_lock(&inode->i_mutex);
 
         if (!access_ok(VERIFY_READ, buf, len)) {
@@ -411,8 +414,6 @@ xip_file_write(struct file *filp, const char __user *buf, size_t len,
         pos = *ppos;
         count = len;
 
-        vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
-
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = mapping->backing_dev_info;
 
@@ -436,6 +437,7 @@ xip_file_write(struct file *filp, const char __user *buf, size_t len,
         current->backing_dev_info = NULL;
  out_up:
         mutex_unlock(&inode->i_mutex);
+        sb_end_write(inode->i_sb);
         return ret;
 }
 EXPORT_SYMBOL_GPL(xip_file_write);
diff --git a/mm/memory.c b/mm/memory.c
index 482f089765ff..57361708d1a5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2650,6 +2650,9 @@ reuse:
                 if (!page_mkwrite) {
                         wait_on_page_locked(dirty_page);
                         set_page_dirty_balance(dirty_page, page_mkwrite);
+                        /* file_update_time outside page_lock */
+                        if (vma->vm_file)
+                                file_update_time(vma->vm_file);
                 }
                 put_page(dirty_page);
                 if (page_mkwrite) {
@@ -2667,10 +2670,6 @@ reuse:
                         }
                 }
 
-                /* file_update_time outside page_lock */
-                if (vma->vm_file)
-                        file_update_time(vma->vm_file);
-
                 return ret;
         }
 
@@ -3339,12 +3338,13 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
         if (dirty_page) {
                 struct address_space *mapping = page->mapping;
+                int dirtied = 0;
 
                 if (set_page_dirty(dirty_page))
-                        page_mkwrite = 1;
+                        dirtied = 1;
                 unlock_page(dirty_page);
                 put_page(dirty_page);
-                if (page_mkwrite && mapping) {
+                if ((dirtied || page_mkwrite) && mapping) {
                         /*
                          * Some device drivers do not set page.mapping but still
                          * dirty their pages
@@ -3353,7 +3353,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 }
 
                 /* file_update_time outside page_lock */
-                if (vma->vm_file)
+                if (vma->vm_file && !page_mkwrite)
                         file_update_time(vma->vm_file);
         } else {
                 unlock_page(vmf.page);