Merge commit '4cb38750d49010ae72e718d46605ac9ba5a851b4' into stable/for-linus-3.6

* commit '4cb38750d49010ae72e718d46605ac9ba5a851b4': (6849 commits)
  bcma: fix invalid PMU chip control masks
  [libata] pata_cmd64x: whitespace cleanup
  libata-acpi: fix up for acpi_pm_device_sleep_state API
  sata_dwc_460ex: device tree may specify dma_channel
  ahci, trivial: fixed coding style issues related to braces
  ahci_platform: add hibernation callbacks
  libata-eh.c: local functions should not be exposed globally
  libata-transport.c: local functions should not be exposed globally
  sata_dwc_460ex: support hardreset
  ata: use module_pci_driver
  drivers/ata/pata_pcmcia.c: adjust suspicious bit operation
  pata_imx: Convert to clk_prepare_enable/clk_disable_unprepare
  ahci: Enable SB600 64bit DMA on MSI K9AGM2 (MS-7327) v2
  [libata] Prevent interface errors with Seagate FreeAgent GoFlex
  drivers/acpi/glue: revert accidental license-related 6b66d95895c bits
  libata-acpi: add missing inlines in libata.h
  i2c-omap: Add support for I2C_M_STOP message flag
  i2c: Fall back to emulated SMBus if the operation isn't supported natively
  i2c: Add SCCB support
  i2c-tiny-usb: Add support for the Robofuzz OSIF USB/I2C converter
  ...

1 files changed, 39 insertions, 24 deletions

diff --git a/fs/sync.c b/fs/sync.c
index 11e3d1c4490..eb8722dc556 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -29,16 +29,6 @@
  */
 static int __sync_filesystem(struct super_block *sb, int wait)
 {
-	/*
-	 * This should be safe, as we require bdi backing to actually
-	 * write out data in the first place
-	 */
-	if (sb->s_bdi == &noop_backing_dev_info)
-		return 0;
-
-	if (sb->s_qcop && sb->s_qcop->quota_sync)
-		sb->s_qcop->quota_sync(sb, -1, wait);
-
 	if (wait)
 		sync_inodes_sb(sb);
 	else
@@ -77,29 +67,48 @@ int sync_filesystem(struct super_block *sb)
 }
 EXPORT_SYMBOL_GPL(sync_filesystem);
 
-static void sync_one_sb(struct super_block *sb, void *arg)
+static void sync_inodes_one_sb(struct super_block *sb, void *arg)
 {
 	if (!(sb->s_flags & MS_RDONLY))
-		__sync_filesystem(sb, *(int *)arg);
+		sync_inodes_sb(sb);
 }
-/*
- * Sync all the data for all the filesystems (called by sys_sync() and
- * emergency sync)
- */
-static void sync_filesystems(int wait)
+
+static void sync_fs_one_sb(struct super_block *sb, void *arg)
 {
-	iterate_supers(sync_one_sb, &wait);
+	if (!(sb->s_flags & MS_RDONLY) && sb->s_op->sync_fs)
+		sb->s_op->sync_fs(sb, *(int *)arg);
+}
+
+static void fdatawrite_one_bdev(struct block_device *bdev, void *arg)
+{
+	filemap_fdatawrite(bdev->bd_inode->i_mapping);
+}
+
+static void fdatawait_one_bdev(struct block_device *bdev, void *arg)
+{
+	filemap_fdatawait(bdev->bd_inode->i_mapping);
 }
 
 /*
- * sync everything.  Start out by waking pdflush, because that writes back
- * all queues in parallel.
+ * Sync everything. We start by waking flusher threads so that most of
+ * writeback runs on all devices in parallel. Then we sync all inodes reliably
+ * which effectively also waits for all flusher threads to finish doing
+ * writeback. At this point all data is on disk so metadata should be stable
+ * and we tell filesystems to sync their metadata via ->sync_fs() calls.
+ * Finally, we writeout all block devices because some filesystems (e.g. ext2)
+ * just write metadata (such as inodes or bitmaps) to block device page cache
+ * and do not sync it on their own in ->sync_fs().
  */
 SYSCALL_DEFINE0(sync)
 {
+	int nowait = 0, wait = 1;
+
 	wakeup_flusher_threads(0, WB_REASON_SYNC);
-	sync_filesystems(0);
-	sync_filesystems(1);
+	iterate_supers(sync_inodes_one_sb, NULL);
+	iterate_supers(sync_fs_one_sb, &nowait);
+	iterate_supers(sync_fs_one_sb, &wait);
+	iterate_bdevs(fdatawrite_one_bdev, NULL);
+	iterate_bdevs(fdatawait_one_bdev, NULL);
 	if (unlikely(laptop_mode))
 		laptop_sync_completion();
 	return 0;
@@ -107,12 +116,18 @@ SYSCALL_DEFINE0(sync)
 
 static void do_sync_work(struct work_struct *work)
 {
+	int nowait = 0;
+
 	/*
 	 * Sync twice to reduce the possibility we skipped some inodes / pages
 	 * because they were temporarily locked
 	 */
-	sync_filesystems(0);
-	sync_filesystems(0);
+	iterate_supers(sync_inodes_one_sb, &nowait);
+	iterate_supers(sync_fs_one_sb, &nowait);
+	iterate_bdevs(fdatawrite_one_bdev, NULL);
+	iterate_supers(sync_inodes_one_sb, &nowait);
+	iterate_supers(sync_fs_one_sb, &nowait);
+	iterate_bdevs(fdatawrite_one_bdev, NULL);
 	printk("Emergency Sync complete\n");
 	kfree(work);
 }