Commit 2687a356 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Matthew Wilcox
Browse files

Add lock_page_killable 



This routine is like lock_page, but can be interrupted by a fatal signal

Signed-off-by: default avatarMatthew Wilcox <willy@linux.intel.com>
parent f776d12d

include/linux/pagemap.h

+14 −0
Original line number Diff line number Diff line
@@ -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.

mm/filemap.c

+14 −0
Original line number Diff line number Diff line
@@ -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.