Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / fs / buffer.c

diff --git a/fs/buffer.c b/fs/buffer.c
index c7062c8..9f6d2e4 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2306,8 +2306,8 @@ EXPORT_SYMBOL(block_commit_write);
  * beyond EOF, then the page is guaranteed safe against truncation until we
  * unlock the page.
  *
- * Direct callers of this function should call vfs_check_frozen() so that page
- * fault does not busyloop until the fs is thawed.
+ * Direct callers of this function should protect against filesystem freezing
+ * using sb_start_write() - sb_end_write() functions.
  */
 int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
                         get_block_t get_block)
@@ -2318,6 +2318,12 @@ int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
        loff_t size;
        int ret;
 
+       /*
+        * Update file times before taking page lock. We may end up failing the
+        * fault so this update may be superfluous but who really cares...
+        */
+       file_update_time(vma->vm_file);
+
        lock_page(page);
        size = i_size_read(inode);
        if ((page->mapping != inode->i_mapping) ||
@@ -2339,18 +2345,7 @@ int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 
        if (unlikely(ret < 0))
                goto out_unlock;
-       /*
-        * Freezing in progress? We check after the page is marked dirty and
-        * with page lock held so if the test here fails, we are sure freezing
-        * code will wait during syncing until the page fault is done - at that
-        * point page will be dirty and unlocked so freezing code will write it
-        * and writeprotect it again.
-        */
        set_page_dirty(page);
-       if (inode->i_sb->s_frozen != SB_UNFROZEN) {
-               ret = -EAGAIN;
-               goto out_unlock;
-       }
        wait_on_page_writeback(page);
        return 0;
 out_unlock:
@@ -2365,12 +2360,9 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
        int ret;
        struct super_block *sb = vma->vm_file->f_path.dentry->d_inode->i_sb;
 
-       /*
-        * This check is racy but catches the common case. The check in
-        * __block_page_mkwrite() is reliable.
-        */
-       vfs_check_frozen(sb, SB_FREEZE_WRITE);
+       sb_start_pagefault(sb);
        ret = __block_page_mkwrite(vma, vmf, get_block);
+       sb_end_pagefault(sb);
        return block_page_mkwrite_return(ret);
 }
 EXPORT_SYMBOL(block_page_mkwrite);