Re: Linux 3.0.51

[Greg KH <gregkh@linuxfoundation.org>]

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index b1c921c..6ff5af4 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -6,14 +6,6 @@ be removed from this file.
 
 ---------------------------
 
-What:	x86 floppy disable_hlt
-When:	2012
-Why:	ancient workaround of dubious utility clutters the
-	code used by everybody else.
-Who:	Len Brown <len.brown@intel.com>
-
----------------------------
-
 What:	CONFIG_APM_CPU_IDLE, and its ability to call APM BIOS in idle
 When:	2012
 Why:	This optional sub-feature of APM is of dubious reliability,
diff --git a/Makefile b/Makefile
index 0210b63..9ec465b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 3
 PATCHLEVEL = 0
-SUBLEVEL = 50
+SUBLEVEL = 51
 EXTRAVERSION =
 NAME = Sneaky Weasel
 
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index c2ff2a1..f0d89d9 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -93,10 +93,6 @@ do {									\
 			"memory");					\
 } while (0)
 
-/*
- * disable hlt during certain critical i/o operations
- */
-#define HAVE_DISABLE_HLT
 #else
 
 /* frame pointer must be last for get_wchan */
@@ -392,9 +388,6 @@ static inline void clflush(volatile void *__p)
 
 #define nop() asm volatile ("nop")
 
-void disable_hlt(void);
-void enable_hlt(void);
-
 void cpu_idle_wait(void);
 
 extern unsigned long arch_align_stack(unsigned long sp);
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index e1ba8cb..4272502 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -341,34 +341,10 @@ void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);
 #endif
 
-#ifdef CONFIG_X86_32
-/*
- * This halt magic was a workaround for ancient floppy DMA
- * wreckage. It should be safe to remove.
- */
-static int hlt_counter;
-void disable_hlt(void)
-{
-	hlt_counter++;
-}
-EXPORT_SYMBOL(disable_hlt);
-
-void enable_hlt(void)
-{
-	hlt_counter--;
-}
-EXPORT_SYMBOL(enable_hlt);
-
-static inline int hlt_use_halt(void)
-{
-	return (!hlt_counter && boot_cpu_data.hlt_works_ok);
-}
-#else
 static inline int hlt_use_halt(void)
 {
 	return 1;
 }
-#endif
 
 /*
  * We use this if we don't have any better
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 9955a53..215ddc8 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -1032,37 +1032,6 @@ static int fd_wait_for_completion(unsigned long delay, timeout_fn function)
 	return 0;
 }
 
-static DEFINE_SPINLOCK(floppy_hlt_lock);
-static int hlt_disabled;
-static void floppy_disable_hlt(void)
-{
-	unsigned long flags;
-
-	WARN_ONCE(1, "floppy_disable_hlt() scheduled for removal in 2012");
-	spin_lock_irqsave(&floppy_hlt_lock, flags);
-	if (!hlt_disabled) {
-		hlt_disabled = 1;
-#ifdef HAVE_DISABLE_HLT
-		disable_hlt();
-#endif
-	}
-	spin_unlock_irqrestore(&floppy_hlt_lock, flags);
-}
-
-static void floppy_enable_hlt(void)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&floppy_hlt_lock, flags);
-	if (hlt_disabled) {
-		hlt_disabled = 0;
-#ifdef HAVE_DISABLE_HLT
-		enable_hlt();
-#endif
-	}
-	spin_unlock_irqrestore(&floppy_hlt_lock, flags);
-}
-
 static void setup_DMA(void)
 {
 	unsigned long f;
@@ -1107,7 +1076,6 @@ static void setup_DMA(void)
 	fd_enable_dma();
 	release_dma_lock(f);
 #endif
-	floppy_disable_hlt();
 }
 
 static void show_floppy(void);
@@ -1709,7 +1677,6 @@ irqreturn_t floppy_interrupt(int irq, void *dev_id)
 	fd_disable_dma();
 	release_dma_lock(f);
 
-	floppy_enable_hlt();
 	do_floppy = NULL;
 	if (fdc >= N_FDC || FDCS->address == -1) {
 		/* we don't even know which FDC is the culprit */
@@ -1858,8 +1825,6 @@ static void floppy_shutdown(unsigned long data)
 		show_floppy();
 	cancel_activity();
 
-	floppy_enable_hlt();
-
 	flags = claim_dma_lock();
 	fd_disable_dma();
 	release_dma_lock(flags);
@@ -4198,6 +4163,7 @@ static int __init floppy_init(void)
 
 		disks[dr]->queue = blk_init_queue(do_fd_request, &floppy_lock);
 		if (!disks[dr]->queue) {
+			put_disk(disks[dr]);
 			err = -ENOMEM;
 			goto out_put_disk;
 		}
@@ -4504,7 +4470,6 @@ static void floppy_release_irq_and_dma(void)
 #if N_FDC > 1
 	set_dor(1, ~8, 0);
 #endif
-	floppy_enable_hlt();
 
 	if (floppy_track_buffer && max_buffer_sectors) {
 		tmpsize = max_buffer_sectors * 1024;
diff --git a/drivers/gpu/drm/nouveau/nv04_dac.c b/drivers/gpu/drm/nouveau/nv04_dac.c
index e000455..2d6bfd0 100644
--- a/drivers/gpu/drm/nouveau/nv04_dac.c
+++ b/drivers/gpu/drm/nouveau/nv04_dac.c
@@ -209,7 +209,7 @@ out:
 	NVWriteVgaCrtc(dev, 0, NV_CIO_CR_MODE_INDEX, saved_cr_mode);
 
 	if (blue == 0x18) {
-		NV_INFO(dev, "Load detected on head A\n");
+		NV_DEBUG(dev, "Load detected on head A\n");
 		return connector_status_connected;
 	}
 
@@ -323,7 +323,7 @@ nv17_dac_detect(struct drm_encoder *encoder, struct drm_connector *connector)
 
 	if (nv17_dac_sample_load(encoder) &
 	    NV_PRAMDAC_TEST_CONTROL_SENSEB_ALLHI) {
-		NV_INFO(dev, "Load detected on output %c\n",
+		NV_DEBUG(dev, "Load detected on output %c\n",
 			'@' + ffs(dcb->or));
 		return connector_status_connected;
 	} else {
@@ -398,7 +398,7 @@ static void nv04_dac_commit(struct drm_encoder *encoder)
 
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
-	NV_INFO(dev, "Output %s is running on CRTC %d using output %c\n",
+	NV_DEBUG(dev, "Output %s is running on CRTC %d using output %c\n",
 		drm_get_connector_name(&nouveau_encoder_connector_get(nv_encoder)->base),
 		nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
 }
@@ -447,7 +447,7 @@ static void nv04_dac_dpms(struct drm_encoder *encoder, int mode)
 		return;
 	nv_encoder->last_dpms = mode;
 
-	NV_INFO(dev, "Setting dpms mode %d on vga encoder (output %d)\n",
+	NV_DEBUG(dev, "Setting dpms mode %d on vga encoder (output %d)\n",
 		     mode, nv_encoder->dcb->index);
 
 	nv04_dac_update_dacclk(encoder, mode == DRM_MODE_DPMS_ON);
diff --git a/drivers/gpu/drm/nouveau/nv04_dfp.c b/drivers/gpu/drm/nouveau/nv04_dfp.c
index 12098bf..752440c 100644
--- a/drivers/gpu/drm/nouveau/nv04_dfp.c
+++ b/drivers/gpu/drm/nouveau/nv04_dfp.c
@@ -468,7 +468,7 @@ static void nv04_dfp_commit(struct drm_encoder *encoder)
 
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
-	NV_INFO(dev, "Output %s is running on CRTC %d using output %c\n",
+	NV_DEBUG(dev, "Output %s is running on CRTC %d using output %c\n",
 		drm_get_connector_name(&nouveau_encoder_connector_get(nv_encoder)->base),
 		nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
 }
@@ -511,7 +511,7 @@ static void nv04_lvds_dpms(struct drm_encoder *encoder, int mode)
 		return;
 	nv_encoder->last_dpms = mode;
 
-	NV_INFO(dev, "Setting dpms mode %d on lvds encoder (output %d)\n",
+	NV_DEBUG(dev, "Setting dpms mode %d on lvds encoder (output %d)\n",
 		     mode, nv_encoder->dcb->index);
 
 	if (was_powersaving && is_powersaving_dpms(mode))
@@ -556,7 +556,7 @@ static void nv04_tmds_dpms(struct drm_encoder *encoder, int mode)
 		return;
 	nv_encoder->last_dpms = mode;
 
-	NV_INFO(dev, "Setting dpms mode %d on tmds encoder (output %d)\n",
+	NV_DEBUG(dev, "Setting dpms mode %d on tmds encoder (output %d)\n",
 		     mode, nv_encoder->dcb->index);
 
 	nv04_dfp_update_backlight(encoder, mode);
diff --git a/drivers/gpu/drm/nouveau/nv04_tv.c b/drivers/gpu/drm/nouveau/nv04_tv.c
index 3eb605d..4de1fbe 100644
--- a/drivers/gpu/drm/nouveau/nv04_tv.c
+++ b/drivers/gpu/drm/nouveau/nv04_tv.c
@@ -69,7 +69,7 @@ static void nv04_tv_dpms(struct drm_encoder *encoder, int mode)
 	struct nv04_mode_state *state = &dev_priv->mode_reg;
 	uint8_t crtc1A;
 
-	NV_INFO(dev, "Setting dpms mode %d on TV encoder (output %d)\n",
+	NV_DEBUG(dev, "Setting dpms mode %d on TV encoder (output %d)\n",
 		mode, nv_encoder->dcb->index);
 
 	state->pllsel &= ~(PLLSEL_TV_CRTC1_MASK | PLLSEL_TV_CRTC2_MASK);
@@ -162,7 +162,7 @@ static void nv04_tv_commit(struct drm_encoder *encoder)
 
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
-	NV_INFO(dev, "Output %s is running on CRTC %d using output %c\n",
+	NV_DEBUG(dev, "Output %s is running on CRTC %d using output %c\n",
 		      drm_get_connector_name(&nouveau_encoder_connector_get(nv_encoder)->base), nv_crtc->index,
 		      '@' + ffs(nv_encoder->dcb->or));
 }
diff --git a/mm/rmap.c b/mm/rmap.c
index 23295f65..30e44cb 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -57,6 +57,7 @@
 #include <linux/mmu_notifier.h>
 #include <linux/migrate.h>
 #include <linux/hugetlb.h>
+#include <linux/backing-dev.h>
 
 #include <asm/tlbflush.h>
 
@@ -936,11 +937,8 @@ int page_mkclean(struct page *page)
 
 	if (page_mapped(page)) {
 		struct address_space *mapping = page_mapping(page);
-		if (mapping) {
+		if (mapping)
 			ret = page_mkclean_file(mapping, page);
-			if (page_test_and_clear_dirty(page_to_pfn(page), 1))
-				ret = 1;
-		}
 	}
 
 	return ret;
@@ -1121,6 +1119,8 @@ void page_add_file_rmap(struct page *page)
  */
 void page_remove_rmap(struct page *page)
 {
+	struct address_space *mapping = page_mapping(page);
+
 	/* page still mapped by someone else? */
 	if (!atomic_add_negative(-1, &page->_mapcount))
 		return;
@@ -1131,8 +1131,19 @@ void page_remove_rmap(struct page *page)
 	 * this if the page is anon, so about to be freed; but perhaps
 	 * not if it's in swapcache - there might be another pte slot
 	 * containing the swap entry, but page not yet written to swap.
+	 *
+	 * And we can skip it on file pages, so long as the filesystem
+	 * participates in dirty tracking; but need to catch shm and tmpfs
+	 * and ramfs pages which have been modified since creation by read
+	 * fault.
+	 *
+	 * Note that mapping must be decided above, before decrementing
+	 * mapcount (which luckily provides a barrier): once page is unmapped,
+	 * it could be truncated and page->mapping reset to NULL at any moment.
+	 * Note also that we are relying on page_mapping(page) to set mapping
+	 * to &swapper_space when PageSwapCache(page).
 	 */
-	if ((!PageAnon(page) || PageSwapCache(page)) &&
+	if (mapping && !mapping_cap_account_dirty(mapping) &&
 	    page_test_and_clear_dirty(page_to_pfn(page), 1))
 		set_page_dirty(page);
 	/*