Freeze all filesystems during system suspend/hibernate.

Rebased http://marc.info/?l=linux-kernel&m=132775832509351&w=4 to 3.3-rc3

1 files changed, 287 insertions, 0 deletions

diff --git a/hibernate-freeze-filesystems.patch b/hibernate-freeze-filesystems.patch
new file mode 100644
index 000000000..841cab643
--- /dev/null
+++ b/hibernate-freeze-filesystems.patch
@@ -0,0 +1,287 @@
+commit b94887bbc0621e1e8402e7f0ec4bc3adf46c9a6e
+Author: Rafael J. Wysocki <rjw@sisk.pl>
+Date:   Fri Feb 17 12:42:08 2012 -0500
+
+    Freeze all filesystems during system suspend and (kernel-driven)
+    hibernation by calling freeze_supers() for all superblocks and thaw
+    them during the subsequent resume with the help of thaw_supers().
+    
+    This makes filesystems stay in a consistent state in case something
+    goes wrong between system suspend (or hibernation) and the subsequent
+    resume (e.g. journal replays won't be necessary in those cases).  In
+    particular, this should help to solve a long-standing issue that, in
+    some cases, during resume from hibernation the boot loader causes the
+    journal to be replied for the filesystem containing the kernel image
+    and/or initrd causing it to become inconsistent with the information
+    stored in the hibernation image.
+    
+    The user-space-driven hibernation (s2disk) is not covered by this
+    change, because the freezing of filesystems prevents s2disk from
+    accessing device special files it needs to do its job.
+    
+    This change is based on earlier work by Nigel Cunningham.
+    
+    Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
+    
+    Rebased to 3.3-rc3 by Josh Boyer <jwboyer@redhat.com>
+
+diff --git a/fs/super.c b/fs/super.c
+index 6015c02..c8057fa 100644
+--- a/fs/super.c
++++ b/fs/super.c
+@@ -594,6 +594,79 @@ void iterate_supers_type(struct file_system_type *type,
+ EXPORT_SYMBOL(iterate_supers_type);
+ 
+ /**
++ *	thaw_supers - call thaw_super() for all superblocks
++ */
++void thaw_supers(void)
++{
++	struct super_block *sb, *p = NULL;
++
++	spin_lock(&sb_lock);
++	list_for_each_entry(sb, &super_blocks, s_list) {
++		if (hlist_unhashed(&sb->s_instances))
++			continue;
++		sb->s_count++;
++		spin_unlock(&sb_lock);
++
++		if (sb->s_flags & MS_FROZEN) {
++			thaw_super(sb);
++			sb->s_flags &= ~MS_FROZEN;
++		}
++
++		spin_lock(&sb_lock);
++		if (p)
++			__put_super(p);
++		p = sb;
++	}
++	if (p)
++		__put_super(p);
++	spin_unlock(&sb_lock);
++}
++
++/**
++ *	freeze_supers - call freeze_super() for all superblocks
++ */
++int freeze_supers(void)
++{
++	struct super_block *sb, *p = NULL;
++	int error = 0;
++
++	spin_lock(&sb_lock);
++	/*
++	 * Freeze in reverse order so filesystems depending on others are
++	 * frozen in the right order (eg. loopback on ext3).
++	 */
++	list_for_each_entry_reverse(sb, &super_blocks, s_list) {
++		if (hlist_unhashed(&sb->s_instances))
++			continue;
++		sb->s_count++;
++		spin_unlock(&sb_lock);
++
++		if (sb->s_root && sb->s_frozen != SB_FREEZE_TRANS
++		    && !(sb->s_flags & MS_RDONLY)) {
++			error = freeze_super(sb);
++			if (!error)
++				sb->s_flags |= MS_FROZEN;
++		}
++
++		spin_lock(&sb_lock);
++		if (error)
++			break;
++		if (p)
++			__put_super(p);
++		p = sb;
++	}
++	if (p)
++		__put_super(p);
++	spin_unlock(&sb_lock);
++
++	if (error)
++		thaw_supers();
++
++	return error;
++}
++
++
++/**
+  *	get_super - get the superblock of a device
+  *	@bdev: device to get the superblock for
+  *	
+diff --git a/include/linux/fs.h b/include/linux/fs.h
+index 386da09..a164f4a 100644
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -210,6 +210,7 @@ struct inodes_stat_t {
+ #define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
+ #define MS_I_VERSION	(1<<23) /* Update inode I_version field */
+ #define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
++#define MS_FROZEN	(1<<25) /* Frozen filesystem */
+ #define MS_NOSEC	(1<<28)
+ #define MS_BORN		(1<<29)
+ #define MS_ACTIVE	(1<<30)
+@@ -2501,6 +2502,8 @@ extern void drop_super(struct super_block *sb);
+ extern void iterate_supers(void (*)(struct super_block *, void *), void *);
+ extern void iterate_supers_type(struct file_system_type *,
+ 			        void (*)(struct super_block *, void *), void *);
++extern int freeze_supers(void);
++extern void thaw_supers(void);
+ 
+ extern int dcache_dir_open(struct inode *, struct file *);
+ extern int dcache_dir_close(struct inode *, struct file *);
+diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
+index 6d6d288..492fc62 100644
+--- a/kernel/power/hibernate.c
++++ b/kernel/power/hibernate.c
+@@ -626,12 +626,17 @@ int hibernate(void)
+ 	if (error)
+ 		goto Finish;
+ 
+-	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
++	error = freeze_supers();
+ 	if (error)
+ 		goto Thaw;
++
++	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
++	if (error)
++		goto Thaw_fs;
++
+ 	if (freezer_test_done) {
+ 		freezer_test_done = false;
+-		goto Thaw;
++		goto Thaw_fs;
+ 	}
+ 
+ 	if (in_suspend) {
+@@ -655,6 +660,8 @@ int hibernate(void)
+ 		pr_debug("PM: Image restored successfully.\n");
+ 	}
+ 
++ Thaw_fs:
++	thaw_supers();
+  Thaw:
+ 	thaw_processes();
+  Finish:
+diff --git a/kernel/power/power.h b/kernel/power/power.h
+index 21724ee..40d6f64 100644
+--- a/kernel/power/power.h
++++ b/kernel/power/power.h
+@@ -1,3 +1,4 @@
++#include <linux/fs.h>
+ #include <linux/suspend.h>
+ #include <linux/suspend_ioctls.h>
+ #include <linux/utsname.h>
+@@ -227,45 +228,3 @@ enum {
+ #define TEST_MAX	(__TEST_AFTER_LAST - 1)
+ 
+ extern int pm_test_level;
+-
+-#ifdef CONFIG_SUSPEND_FREEZER
+-static inline int suspend_freeze_processes(void)
+-{
+-	int error;
+-
+-	error = freeze_processes();
+-
+-	/*
+-	 * freeze_processes() automatically thaws every task if freezing
+-	 * fails. So we need not do anything extra upon error.
+-	 */
+-	if (error)
+-		goto Finish;
+-
+-	error = freeze_kernel_threads();
+-
+-	/*
+-	 * freeze_kernel_threads() thaws only kernel threads upon freezing
+-	 * failure. So we have to thaw the userspace tasks ourselves.
+-	 */
+-	if (error)
+-		thaw_processes();
+-
+- Finish:
+-	return error;
+-}
+-
+-static inline void suspend_thaw_processes(void)
+-{
+-	thaw_processes();
+-}
+-#else
+-static inline int suspend_freeze_processes(void)
+-{
+-	return 0;
+-}
+-
+-static inline void suspend_thaw_processes(void)
+-{
+-}
+-#endif
+diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
+index 4fd51be..5f51fc7 100644
+--- a/kernel/power/suspend.c
++++ b/kernel/power/suspend.c
+@@ -29,6 +29,62 @@
+ 
+ #include "power.h"
+ 
++#ifdef CONFIG_SUSPEND_FREEZER
++
++static inline int suspend_freeze_processes(void)
++{
++	int error;
++
++	error = freeze_processes();
++
++	/*
++	 * freeze_processes() automatically thaws every task if freezing
++	 * fails. So we need not do anything extra upon error.
++	 */
++
++	if (error)
++		goto Finish;
++
++	error = freeze_supers();
++	if (error) {
++		thaw_processes();
++		goto Finish;
++	}
++
++	error = freeze_kernel_threads();
++
++	/*
++	 * freeze_kernel_threads() thaws only kernel threads upon freezing
++	 * failure. So we have to thaw the userspace tasks ourselves.
++	 */
++	if (error) {
++		thaw_supers();
++		thaw_processes();
++	}
++
++Finish:
++	return error;
++}
++
++static inline void suspend_thaw_processes(void)
++{
++	thaw_supers();
++	thaw_processes();
++}
++
++#else /* !CONFIG_SUSPEND_FREEZER */
++
++static inline int suspend_freeze_processes(void)
++{
++	return 0;
++}
++
++static inline void suspend_thaw_processes(void)
++{
++}
++
++#endif /* !CONFIG_SUSPEND_FREEZER */
++
+ const char *const pm_states[PM_SUSPEND_MAX] = {
+ 	[PM_SUSPEND_STANDBY]	= "standby",
+ 	[PM_SUSPEND_MEM]	= "mem",