[GIT,PULL] KVM updates for the 2.6.38 merge window

Commit Message

Linus Torvalds Jan. 12, 2011, 8:53 p.m. UTC

None

Patch

 include/linux/mm.h |    1 +
 mm/filemap.c       |    6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 721f451..dc83565 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -145,6 +145,7 @@  extern pgprot_t protection_map[16];
 #define FAULT_FLAG_NONLINEAR	0x02	/* Fault was via a nonlinear mapping */
 #define FAULT_FLAG_MKWRITE	0x04	/* Fault was mkwrite of existing pte */
 #define FAULT_FLAG_ALLOW_RETRY	0x08	/* Retry fault if blocking */
+#define FAULT_FLAG_RETRY_NOWAIT	0x10	/* Don't drop mmap_sem and wait when retrying */
 
 /*
  * This interface is used by x86 PAT code to identify a pfn mapping that is
diff --git a/mm/filemap.c b/mm/filemap.c
index ca38939..10eecf7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -621,8 +621,10 @@  int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
 		__lock_page(page);
 		return 1;
 	} else {
-		up_read(&mm->mmap_sem);
-		wait_on_page_locked(page);
+		if (!(flags & FAULT_FLAG_RETRY_NOWAIT)) {
+			up_read(&mm->mmap_sem);
+			wait_on_page_locked(page);
+		}
 		return 0;
 	}
 }