Merge commit 'v3.6-rc1' into linux-next

* commit 'v3.6-rc1': (9532 commits)
  Linux 3.6-rc1
  mm: remove node_start_pfn checking in new WARN_ON for now
  ARM: mmp: add missing irqs.h
  arm: mvebu: fix typo in .dtsi comment for Armada XP SoCs
  ARM: PRIMA2: delete redundant codes to restore LATCHED when timer resumes
  libceph: fix crypto key null deref, memory leak
  ceph: simplify+fix atomic_open
  sh: explicitly include sh_dma.h in setup-sh7722.c
  um: Add arch/x86/um to MAINTAINERS
  um: pass siginfo to guest process
  um: fix ubd_file_size for read-only files
  md/dm-raid: DM_RAID should select MD_RAID10
  md/raid1: submit IO from originating thread instead of md thread.
  raid5: raid5d handle stripe in batch way
  raid5: make_request use batch stripe release
  um: pull interrupt_end() into userspace()
  um: split syscall_trace(), pass pt_regs to it
  um: switch UPT_SET_RETURN_VALUE and regs_return_value to pt_regs
  MIPS: Loongson 2: Sort out clock managment.
  locks: remove unused lm_release_private
  ...

1 files changed, 23 insertions, 27 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 838a9cf246bd..9f6d2e41281d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1036,6 +1036,9 @@ grow_buffers(struct block_device *bdev, sector_t block, int size)
 static struct buffer_head *
 __getblk_slow(struct block_device *bdev, sector_t block, int size)
 {
+	int ret;
+	struct buffer_head *bh;
+
 	/* Size must be multiple of hard sectorsize */
 	if (unlikely(size & (bdev_logical_block_size(bdev)-1) ||
 			(size < 512 || size > PAGE_SIZE))) {
@@ -1048,20 +1051,21 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size)
 		return NULL;
 	}
 
-	for (;;) {
-		struct buffer_head * bh;
-		int ret;
+retry:
+	bh = __find_get_block(bdev, block, size);
+	if (bh)
+		return bh;
 
+	ret = grow_buffers(bdev, block, size);
+	if (ret == 0) {
+		free_more_memory();
+		goto retry;
+	} else if (ret > 0) {
 		bh = __find_get_block(bdev, block, size);
 		if (bh)
 			return bh;
-
-		ret = grow_buffers(bdev, block, size);
-		if (ret < 0)
-			return NULL;
-		if (ret == 0)
-			free_more_memory();
 	}
+	return NULL;
 }
 
 /*
@@ -2302,8 +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)
@@ -2314,6 +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) ||
@@ -2335,18 +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:
@@ -2361,12 +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);