From 2687a3569e40b1302f96698bcd6329aeb0ce3dd2 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <matthew@wil.cx>
Date: Thu, 6 Dec 2007 11:18:49 -0500
Subject: [PATCH] Add lock_page_killable
This routine is like lock_page, but can be interrupted by a fatal signal
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
include/linux/pagemap.h | 14 ++++++++++++++
mm/filemap.c | 14 ++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index db8a410ae9e1..4b62a105622b 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -157,6 +157,7 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
}
extern void FASTCALL(__lock_page(struct page *page));
+extern int FASTCALL(__lock_page_killable(struct page *page));
extern void FASTCALL(__lock_page_nosync(struct page *page));
extern void FASTCALL(unlock_page(struct page *page));
@@ -170,6 +171,19 @@ static inline void lock_page(struct page *page)
__lock_page(page);
}
+/*
+ * lock_page_killable is like lock_page but can be interrupted by fatal
+ * signals. It returns 0 if it locked the page and -EINTR if it was
+ * killed while waiting.
+ */
+static inline int lock_page_killable(struct page *page)
+{
+ might_sleep();
+ if (TestSetPageLocked(page))
+ return __lock_page_killable(page);
+ return 0;
+}
+
/*
* lock_page_nosync should only be used if we can't pin the page's inode.
* Doesn't play quite so well with block device plugging.
diff --git a/mm/filemap.c b/mm/filemap.c
index 188cf5fd3e8d..ac8f690d2885 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -173,6 +173,12 @@ static int sync_page(void *word)
return 0;
}
+static int sync_page_killable(void *word)
+{
+ sync_page(word);
+ return fatal_signal_pending(current) ? -EINTR : 0;
+}
+
/**
* __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
* @mapping: address space structure to write
@@ -577,6 +583,14 @@ void fastcall __lock_page(struct page *page)
}
EXPORT_SYMBOL(__lock_page);
+int fastcall __lock_page_killable(struct page *page)
+{
+ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
+
+ return __wait_on_bit_lock(page_waitqueue(page), &wait,
+ sync_page_killable, TASK_KILLABLE);
+}
+
/*
* Variant of lock_page that does not require the caller to hold a reference
* on the page's mapping.
--
2.20.1