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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6

Browse Source 
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: PM QOS update fix
  Freezer / cgroup freezer: Update stale locking comments
  PM / platform_bus: Allow runtime PM by default
  i2c: Fix bus-level power management callbacks
  PM QOS update
  PM / Hibernate: Fix block_io.c printk warning
  PM / Hibernate: Group swap ops
  PM / Hibernate: Move the first_sector out of swsusp_write
  PM / Hibernate: Separate block_io
  PM / Hibernate: Snapshot cleanup
  FS / libfs: Implement simple_write_to_buffer
  PM / Hibernate: document open(/dev/snapshot) side effects
  PM / Runtime: Add sysfs debug files
  PM: Improve device power management document
  PM: Update device power management document
  PM: Allow runtime_suspend methods to call pm_schedule_suspend()
  PM: pm_wakeup - switch to using bool
This commit is contained in:
Linus Torvalds
2010-05-20 09:03:55 -07:00
parent fa5312d9e8 25f3a5a285
commit 46ee964509
31 changed files with 1251 additions and 949 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
kernel/cgroup_freezer.c
View File

@@ -89,10 +89,10 @@ struct cgroup_subsys freezer_subsys;
/* Locks taken and their ordering
* ------------------------------
* css_set_lock
* cgroup_mutex (AKA cgroup_lock)
* task->alloc_lock (AKA task_lock)
* freezer->lock
* css_set_lock
* task->alloc_lock (AKA task_lock)
* task->sighand->siglock
*
* cgroup code forces css_set_lock to be taken before task->alloc_lock
@@ -100,33 +100,38 @@ struct cgroup_subsys freezer_subsys;
* freezer_create(), freezer_destroy():
* cgroup_mutex [ by cgroup core ]
*
* can_attach():
* cgroup_mutex
* freezer_can_attach():
* cgroup_mutex (held by caller of can_attach)
*
* cgroup_frozen():
* cgroup_freezing_or_frozen():
* task->alloc_lock (to get task's cgroup)
*
* freezer_fork() (preserving fork() performance means can't take cgroup_mutex):
* task->alloc_lock (to get task's cgroup)
* freezer->lock
* sighand->siglock (if the cgroup is freezing)
*
* freezer_read():
* cgroup_mutex
* freezer->lock
* write_lock css_set_lock (cgroup iterator start)
* task->alloc_lock
* read_lock css_set_lock (cgroup iterator start)
*
* freezer_write() (freeze):
* cgroup_mutex
* freezer->lock
* write_lock css_set_lock (cgroup iterator start)
* task->alloc_lock
* read_lock css_set_lock (cgroup iterator start)
* sighand->siglock
* sighand->siglock (fake signal delivery inside freeze_task())
*
* freezer_write() (unfreeze):
* cgroup_mutex
* freezer->lock
* write_lock css_set_lock (cgroup iterator start)
* task->alloc_lock
* read_lock css_set_lock (cgroup iterator start)
* task->alloc_lock (to prevent races with freeze_task())
* task->alloc_lock (inside thaw_process(), prevents race with refrigerator())
* sighand->siglock
*/
static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,

216
kernel/pm_qos_params.c
View File

@@ -2,7 +2,7 @@
* This module exposes the interface to kernel space for specifying
* QoS dependencies. It provides infrastructure for registration of:
*
* Dependents on a QoS value : register requirements
* Dependents on a QoS value : register requests
* Watchers of QoS value : get notified when target QoS value changes
*
* This QoS design is best effort based. Dependents register their QoS needs.
@@ -14,19 +14,21 @@
* timeout: usec <-- currently not used.
* throughput: kbs (kilo byte / sec)
*
* There are lists of pm_qos_objects each one wrapping requirements, notifiers
* There are lists of pm_qos_objects each one wrapping requests, notifiers
*
* User mode requirements on a QOS parameter register themselves to the
* User mode requests on a QOS parameter register themselves to the
* subsystem by opening the device node /dev/... and writing there request to
* the node. As long as the process holds a file handle open to the node the
* client continues to be accounted for. Upon file release the usermode
* requirement is removed and a new qos target is computed. This way when the
* requirement that the application has is cleaned up when closes the file
* request is removed and a new qos target is computed. This way when the
* request that the application has is cleaned up when closes the file
* pointer or exits the pm_qos_object will get an opportunity to clean up.
*
* Mark Gross <mgross@linux.intel.com>
*/
/*#define DEBUG*/
#include <linux/pm_qos_params.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
@@ -42,25 +44,25 @@
#include <linux/uaccess.h>
/*
* locking rule: all changes to requirements or notifiers lists
* locking rule: all changes to requests or notifiers lists
* or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
* held, taken with _irqsave. One lock to rule them all
*/
struct requirement_list {
struct pm_qos_request_list {
struct list_head list;
union {
s32 value;
s32 usec;
s32 kbps;
};
char *name;
int pm_qos_class;
};
static s32 max_compare(s32 v1, s32 v2);
static s32 min_compare(s32 v1, s32 v2);
struct pm_qos_object {
struct requirement_list requirements;
struct pm_qos_request_list requests;
struct blocking_notifier_head *notifiers;
struct miscdevice pm_qos_power_miscdev;
char *name;
@@ -72,7 +74,7 @@ struct pm_qos_object {
static struct pm_qos_object null_pm_qos;
static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
static struct pm_qos_object cpu_dma_pm_qos = {
.requirements = {LIST_HEAD_INIT(cpu_dma_pm_qos.requirements.list)},
.requests = {LIST_HEAD_INIT(cpu_dma_pm_qos.requests.list)},
.notifiers = &cpu_dma_lat_notifier,
.name = "cpu_dma_latency",
.default_value = 2000 * USEC_PER_SEC,
@@ -82,7 +84,7 @@ static struct pm_qos_object cpu_dma_pm_qos = {
static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
static struct pm_qos_object network_lat_pm_qos = {
.requirements = {LIST_HEAD_INIT(network_lat_pm_qos.requirements.list)},
.requests = {LIST_HEAD_INIT(network_lat_pm_qos.requests.list)},
.notifiers = &network_lat_notifier,
.name = "network_latency",
.default_value = 2000 * USEC_PER_SEC,
@@ -93,8 +95,7 @@ static struct pm_qos_object network_lat_pm_qos = {
static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
static struct pm_qos_object network_throughput_pm_qos = {
.requirements =
{LIST_HEAD_INIT(network_throughput_pm_qos.requirements.list)},
.requests = {LIST_HEAD_INIT(network_throughput_pm_qos.requests.list)},
.notifiers = &network_throughput_notifier,
.name = "network_throughput",
.default_value = 0,
@@ -135,31 +136,34 @@ static s32 min_compare(s32 v1, s32 v2)
}
static void update_target(int target)
static void update_target(int pm_qos_class)
{
s32 extreme_value;
struct requirement_list *node;
struct pm_qos_request_list *node;
unsigned long flags;
int call_notifier = 0;
spin_lock_irqsave(&pm_qos_lock, flags);
extreme_value = pm_qos_array[target]->default_value;
extreme_value = pm_qos_array[pm_qos_class]->default_value;
list_for_each_entry(node,
&pm_qos_array[target]->requirements.list, list) {
extreme_value = pm_qos_array[target]->comparitor(
&pm_qos_array[pm_qos_class]->requests.list, list) {
extreme_value = pm_qos_array[pm_qos_class]->comparitor(
extreme_value, node->value);
}
if (atomic_read(&pm_qos_array[target]->target_value) != extreme_value) {
if (atomic_read(&pm_qos_array[pm_qos_class]->target_value) !=
extreme_value) {
call_notifier = 1;
atomic_set(&pm_qos_array[target]->target_value, extreme_value);
pr_debug(KERN_ERR "new target for qos %d is %d\n", target,
atomic_read(&pm_qos_array[target]->target_value));
atomic_set(&pm_qos_array[pm_qos_class]->target_value,
extreme_value);
pr_debug(KERN_ERR "new target for qos %d is %d\n", pm_qos_class,
atomic_read(&pm_qos_array[pm_qos_class]->target_value));
}
spin_unlock_irqrestore(&pm_qos_lock, flags);
if (call_notifier)
blocking_notifier_call_chain(pm_qos_array[target]->notifiers,
(unsigned long) extreme_value, NULL);
blocking_notifier_call_chain(
pm_qos_array[pm_qos_class]->notifiers,
(unsigned long) extreme_value, NULL);
}
static int register_pm_qos_misc(struct pm_qos_object *qos)
@@ -185,125 +189,112 @@ static int find_pm_qos_object_by_minor(int minor)
}
/**
* pm_qos_requirement - returns current system wide qos expectation
* pm_qos_request - returns current system wide qos expectation
* @pm_qos_class: identification of which qos value is requested
*
* This function returns the current target value in an atomic manner.
*/
int pm_qos_requirement(int pm_qos_class)
int pm_qos_request(int pm_qos_class)
{
return atomic_read(&pm_qos_array[pm_qos_class]->target_value);
}
EXPORT_SYMBOL_GPL(pm_qos_requirement);
EXPORT_SYMBOL_GPL(pm_qos_request);
/**
* pm_qos_add_requirement - inserts new qos request into the list
* pm_qos_add_request - inserts new qos request into the list
* @pm_qos_class: identifies which list of qos request to us
* @name: identifies the request
* @value: defines the qos request
*
* This function inserts a new entry in the pm_qos_class list of requested qos
* performance characteristics. It recomputes the aggregate QoS expectations
* for the pm_qos_class of parameters.
* for the pm_qos_class of parameters, and returns the pm_qos_request list
* element as a handle for use in updating and removal. Call needs to save
* this handle for later use.
*/
int pm_qos_add_requirement(int pm_qos_class, char *name, s32 value)
struct pm_qos_request_list *pm_qos_add_request(int pm_qos_class, s32 value)
{
struct requirement_list *dep;
struct pm_qos_request_list *dep;
unsigned long flags;
dep = kzalloc(sizeof(struct requirement_list), GFP_KERNEL);
dep = kzalloc(sizeof(struct pm_qos_request_list), GFP_KERNEL);
if (dep) {
if (value == PM_QOS_DEFAULT_VALUE)
dep->value = pm_qos_array[pm_qos_class]->default_value;
else
dep->value = value;
dep->name = kstrdup(name, GFP_KERNEL);
if (!dep->name)
goto cleanup;
dep->pm_qos_class = pm_qos_class;
spin_lock_irqsave(&pm_qos_lock, flags);
list_add(&dep->list,
&pm_qos_array[pm_qos_class]->requirements.list);
&pm_qos_array[pm_qos_class]->requests.list);
spin_unlock_irqrestore(&pm_qos_lock, flags);
update_target(pm_qos_class);
return 0;
}
cleanup:
kfree(dep);
return -ENOMEM;
return dep;
}
EXPORT_SYMBOL_GPL(pm_qos_add_requirement);
EXPORT_SYMBOL_GPL(pm_qos_add_request);
/**
* pm_qos_update_requirement - modifies an existing qos request
* @pm_qos_class: identifies which list of qos request to us
* @name: identifies the request
* pm_qos_update_request - modifies an existing qos request
* @pm_qos_req : handle to list element holding a pm_qos request to use
* @value: defines the qos request
*
* Updates an existing qos requirement for the pm_qos_class of parameters along
* Updates an existing qos request for the pm_qos_class of parameters along
* with updating the target pm_qos_class value.
*
* If the named request isn't in the list then no change is made.
* Attempts are made to make this code callable on hot code paths.
*/
int pm_qos_update_requirement(int pm_qos_class, char *name, s32 new_value)
void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
s32 new_value)
{
unsigned long flags;
struct requirement_list *node;
int pending_update = 0;
s32 temp;
spin_lock_irqsave(&pm_qos_lock, flags);
list_for_each_entry(node,
&pm_qos_array[pm_qos_class]->requirements.list, list) {
if (strcmp(node->name, name) == 0) {
if (new_value == PM_QOS_DEFAULT_VALUE)
node->value =
pm_qos_array[pm_qos_class]->default_value;
else
node->value = new_value;
if (pm_qos_req) { /*guard against callers passing in null */
spin_lock_irqsave(&pm_qos_lock, flags);
if (new_value == PM_QOS_DEFAULT_VALUE)
temp = pm_qos_array[pm_qos_req->pm_qos_class]->default_value;
else
temp = new_value;
if (temp != pm_qos_req->value) {
pending_update = 1;
break;
pm_qos_req->value = temp;
}
spin_unlock_irqrestore(&pm_qos_lock, flags);
if (pending_update)
update_target(pm_qos_req->pm_qos_class);
}
spin_unlock_irqrestore(&pm_qos_lock, flags);
if (pending_update)
update_target(pm_qos_class);
return 0;
}
EXPORT_SYMBOL_GPL(pm_qos_update_requirement);
EXPORT_SYMBOL_GPL(pm_qos_update_request);
/**
* pm_qos_remove_requirement - modifies an existing qos request
* @pm_qos_class: identifies which list of qos request to us
* @name: identifies the request
* pm_qos_remove_request - modifies an existing qos request
* @pm_qos_req: handle to request list element
*
* Will remove named qos request from pm_qos_class list of parameters and
* recompute the current target value for the pm_qos_class.
* Will remove pm qos request from the list of requests and
* recompute the current target value for the pm_qos_class. Call this
* on slow code paths.
*/
void pm_qos_remove_requirement(int pm_qos_class, char *name)
void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req)
{
unsigned long flags;
struct requirement_list *node;
int pending_update = 0;
int qos_class;
if (pm_qos_req == NULL)
return;
/* silent return to keep pcm code cleaner */
qos_class = pm_qos_req->pm_qos_class;
spin_lock_irqsave(&pm_qos_lock, flags);
list_for_each_entry(node,
&pm_qos_array[pm_qos_class]->requirements.list, list) {
if (strcmp(node->name, name) == 0) {
kfree(node->name);
list_del(&node->list);
kfree(node);
pending_update = 1;
break;
}
}
list_del(&pm_qos_req->list);
kfree(pm_qos_req);
spin_unlock_irqrestore(&pm_qos_lock, flags);
if (pending_update)
update_target(pm_qos_class);
update_target(qos_class);
}
EXPORT_SYMBOL_GPL(pm_qos_remove_requirement);
EXPORT_SYMBOL_GPL(pm_qos_remove_request);
/**
* pm_qos_add_notifier - sets notification entry for changes to target value
@@ -313,7 +304,7 @@ EXPORT_SYMBOL_GPL(pm_qos_remove_requirement);
* will register the notifier into a notification chain that gets called
* upon changes to the pm_qos_class target value.
*/
int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
{
int retval;
@@ -343,21 +334,16 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
}
EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
#define PID_NAME_LEN 32
static int pm_qos_power_open(struct inode *inode, struct file *filp)
{
int ret;
long pm_qos_class;
char name[PID_NAME_LEN];
pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
if (pm_qos_class >= 0) {
filp->private_data = (void *)pm_qos_class;
snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
ret = pm_qos_add_requirement(pm_qos_class, name,
PM_QOS_DEFAULT_VALUE);
if (ret >= 0)
filp->private_data = (void *) pm_qos_add_request(pm_qos_class,
PM_QOS_DEFAULT_VALUE);
if (filp->private_data)
return 0;
}
return -EPERM;
@@ -365,32 +351,40 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp)
static int pm_qos_power_release(struct inode *inode, struct file *filp)
{
int pm_qos_class;
char name[PID_NAME_LEN];
struct pm_qos_request_list *req;
pm_qos_class = (long)filp->private_data;
snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
pm_qos_remove_requirement(pm_qos_class, name);
req = (struct pm_qos_request_list *)filp->private_data;
pm_qos_remove_request(req);
return 0;
}
static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
size_t count, loff_t *f_pos)
{
s32 value;
int pm_qos_class;
char name[PID_NAME_LEN];
int x;
char ascii_value[11];
struct pm_qos_request_list *pm_qos_req;
pm_qos_class = (long)filp->private_data;
if (count != sizeof(s32))
if (count == sizeof(s32)) {
if (copy_from_user(&value, buf, sizeof(s32)))
return -EFAULT;
} else if (count == 11) { /* len('0x12345678/0') */
if (copy_from_user(ascii_value, buf, 11))
return -EFAULT;
x = sscanf(ascii_value, "%x", &value);
if (x != 1)
return -EINVAL;
pr_debug(KERN_ERR "%s, %d, 0x%x\n", ascii_value, x, value);
} else
return -EINVAL;
if (copy_from_user(&value, buf, sizeof(s32)))
return -EFAULT;
snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
pm_qos_update_requirement(pm_qos_class, name, value);
return sizeof(s32);
pm_qos_req = (struct pm_qos_request_list *)filp->private_data;
pm_qos_update_request(pm_qos_req, value);
return count;
}

3
kernel/power/Makefile
View File

@@ -8,7 +8,8 @@ obj-$(CONFIG_PM_SLEEP) += console.o
obj-$(CONFIG_FREEZER) += process.o
obj-$(CONFIG_SUSPEND) += suspend.o
obj-$(CONFIG_PM_TEST_SUSPEND) += suspend_test.o
obj-$(CONFIG_HIBERNATION) += hibernate.o snapshot.o swap.o user.o
obj-$(CONFIG_HIBERNATION) += hibernate.o snapshot.o swap.o user.o \
block_io.o
obj-$(CONFIG_HIBERNATION_NVS) += hibernate_nvs.o
obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o

103
kernel/power/block_io.c Normal file
View File

@@ -0,0 +1,103 @@
/*
* This file provides functions for block I/O operations on swap/file.
*
* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
*
* This file is released under the GPLv2.
*/
#include <linux/bio.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include "power.h"
/**
* submit - submit BIO request.
* @rw: READ or WRITE.
* @off physical offset of page.
* @page: page we're reading or writing.
* @bio_chain: list of pending biod (for async reading)
*
* Straight from the textbook - allocate and initialize the bio.
* If we're reading, make sure the page is marked as dirty.
* Then submit it and, if @bio_chain == NULL, wait.
*/
static int submit(int rw, struct block_device *bdev, sector_t sector,
struct page *page, struct bio **bio_chain)
{
const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
struct bio *bio;
bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
bio->bi_sector = sector;
bio->bi_bdev = bdev;
bio->bi_end_io = end_swap_bio_read;
if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
(unsigned long long)sector);
bio_put(bio);
return -EFAULT;
}
lock_page(page);
bio_get(bio);
if (bio_chain == NULL) {
submit_bio(bio_rw, bio);
wait_on_page_locked(page);
if (rw == READ)
bio_set_pages_dirty(bio);
bio_put(bio);
} else {
if (rw == READ)
get_page(page); /* These pages are freed later */
bio->bi_private = *bio_chain;
*bio_chain = bio;
submit_bio(bio_rw, bio);
}
return 0;
}
int hib_bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
{
return submit(READ, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
virt_to_page(addr), bio_chain);
}
int hib_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
{
return submit(WRITE, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
virt_to_page(addr), bio_chain);
}
int hib_wait_on_bio_chain(struct bio **bio_chain)
{
struct bio *bio;
struct bio *next_bio;
int ret = 0;
if (bio_chain == NULL)
return 0;
bio = *bio_chain;
if (bio == NULL)
return 0;
while (bio) {
struct page *page;
next_bio = bio->bi_private;
page = bio->bi_io_vec[0].bv_page;
wait_on_page_locked(page);
if (!PageUptodate(page) || PageError(page))
ret = -EIO;
put_page(page);
bio_put(bio);
bio = next_bio;
}
*bio_chain = NULL;
return ret;
}

27
kernel/power/power.h
View File

@@ -97,24 +97,12 @@ extern int hibernate_preallocate_memory(void);
*/
struct snapshot_handle {
loff_t offset; /* number of the last byte ready for reading
* or writing in the sequence
*/
unsigned int cur; /* number of the block of PAGE_SIZE bytes the
* next operation will refer to (ie. current)
*/
unsigned int cur_offset; /* offset with respect to the current
* block (for the next operation)
*/
unsigned int prev; /* number of the block of PAGE_SIZE bytes that
* was the current one previously
*/
void *buffer; /* address of the block to read from
* or write to
*/
unsigned int buf_offset; /* location to read from or write to,
* given as a displacement from 'buffer'
*/
int sync_read; /* Set to one to notify the caller of
* snapshot_write_next() that it may
* need to call wait_on_bio_chain()
@@ -125,12 +113,12 @@ struct snapshot_handle {
* snapshot_read_next()/snapshot_write_next() is allowed to
* read/write data after the function returns
*/
#define data_of(handle) ((handle).buffer + (handle).buf_offset)
#define data_of(handle) ((handle).buffer)
extern unsigned int snapshot_additional_pages(struct zone *zone);
extern unsigned long snapshot_get_image_size(void);
extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_read_next(struct snapshot_handle *handle);
extern int snapshot_write_next(struct snapshot_handle *handle);
extern void snapshot_write_finalize(struct snapshot_handle *handle);
extern int snapshot_image_loaded(struct snapshot_handle *handle);
@@ -154,6 +142,15 @@ extern int swsusp_read(unsigned int *flags_p);
extern int swsusp_write(unsigned int flags);
extern void swsusp_close(fmode_t);
/* kernel/power/block_io.c */
extern struct block_device *hib_resume_bdev;
extern int hib_bio_read_page(pgoff_t page_off, void *addr,
struct bio **bio_chain);
extern int hib_bio_write_page(pgoff_t page_off, void *addr,
struct bio **bio_chain);
extern int hib_wait_on_bio_chain(struct bio **bio_chain);
struct timeval;
/* kernel/power/swsusp.c */
extern void swsusp_show_speed(struct timeval *, struct timeval *,

153
kernel/power/snapshot.c
View File

@@ -1604,14 +1604,9 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
* snapshot_handle structure. The structure gets updated and a pointer
* to it should be passed to this function every next time.
*
* The @count parameter should contain the number of bytes the caller
* wants to read from the snapshot. It must not be zero.
*
* On success the function returns a positive number. Then, the caller
* is allowed to read up to the returned number of bytes from the memory
* location computed by the data_of() macro. The number returned
* may be smaller than @count, but this only happens if the read would
* cross a page boundary otherwise.
* location computed by the data_of() macro.
*
* The function returns 0 to indicate the end of data stream condition,
* and a negative number is returned on error. In such cases the
@@ -1619,7 +1614,7 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
* any more.
*/
int snapshot_read_next(struct snapshot_handle *handle, size_t count)
int snapshot_read_next(struct snapshot_handle *handle)
{
if (handle->cur > nr_meta_pages + nr_copy_pages)
return 0;
@@ -1630,7 +1625,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
if (!buffer)
return -ENOMEM;
}
if (!handle->offset) {
if (!handle->cur) {
int error;
error = init_header((struct swsusp_info *)buffer);
@@ -1639,42 +1634,30 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
handle->buffer = buffer;
memory_bm_position_reset(&orig_bm);
memory_bm_position_reset(&copy_bm);
}
if (handle->prev < handle->cur) {
if (handle->cur <= nr_meta_pages) {
memset(buffer, 0, PAGE_SIZE);
pack_pfns(buffer, &orig_bm);
} else {
struct page *page;
page = pfn_to_page(memory_bm_next_pfn(&copy_bm));
if (PageHighMem(page)) {
/* Highmem pages are copied to the buffer,
* because we can't return with a kmapped
* highmem page (we may not be called again).
*/
void *kaddr;
kaddr = kmap_atomic(page, KM_USER0);
memcpy(buffer, kaddr, PAGE_SIZE);
kunmap_atomic(kaddr, KM_USER0);
handle->buffer = buffer;
} else {
handle->buffer = page_address(page);
}
}
handle->prev = handle->cur;
}
handle->buf_offset = handle->cur_offset;
if (handle->cur_offset + count >= PAGE_SIZE) {
count = PAGE_SIZE - handle->cur_offset;
handle->cur_offset = 0;
handle->cur++;
} else if (handle->cur <= nr_meta_pages) {
memset(buffer, 0, PAGE_SIZE);
pack_pfns(buffer, &orig_bm);
} else {
handle->cur_offset += count;
struct page *page;
page = pfn_to_page(memory_bm_next_pfn(&copy_bm));
if (PageHighMem(page)) {
/* Highmem pages are copied to the buffer,
* because we can't return with a kmapped
* highmem page (we may not be called again).
*/
void *kaddr;
kaddr = kmap_atomic(page, KM_USER0);
memcpy(buffer, kaddr, PAGE_SIZE);
kunmap_atomic(kaddr, KM_USER0);
handle->buffer = buffer;
} else {
handle->buffer = page_address(page);
}
}
handle->offset += count;
return count;
handle->cur++;
return PAGE_SIZE;
}
/**
@@ -2133,14 +2116,9 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
* snapshot_handle structure. The structure gets updated and a pointer
* to it should be passed to this function every next time.
*
* The @count parameter should contain the number of bytes the caller
* wants to write to the image. It must not be zero.
*
* On success the function returns a positive number. Then, the caller
* is allowed to write up to the returned number of bytes to the memory
* location computed by the data_of() macro. The number returned
* may be smaller than @count, but this only happens if the write would
* cross a page boundary otherwise.
* location computed by the data_of() macro.
*
* The function returns 0 to indicate the "end of file" condition,
* and a negative number is returned on error. In such cases the
@@ -2148,16 +2126,18 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
* any more.
*/
int snapshot_write_next(struct snapshot_handle *handle, size_t count)
int snapshot_write_next(struct snapshot_handle *handle)
{
static struct chain_allocator ca;
int error = 0;
/* Check if we have already loaded the entire image */
if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
return 0;
if (handle->offset == 0) {
handle->sync_read = 1;
if (!handle->cur) {
if (!buffer)
/* This makes the buffer be freed by swsusp_free() */
buffer = get_image_page(GFP_ATOMIC, PG_ANY);
@@ -2166,56 +2146,43 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
return -ENOMEM;
handle->buffer = buffer;
}
handle->sync_read = 1;
if (handle->prev < handle->cur) {
if (handle->prev == 0) {
error = load_header(buffer);
} else if (handle->cur == 1) {
error = load_header(buffer);
if (error)
return error;
error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
if (error)
return error;
} else if (handle->cur <= nr_meta_pages + 1) {
error = unpack_orig_pfns(buffer, &copy_bm);
if (error)
return error;
if (handle->cur == nr_meta_pages + 1) {
error = prepare_image(&orig_bm, &copy_bm);
if (error)
return error;
error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
if (error)
return error;
} else if (handle->prev <= nr_meta_pages) {
error = unpack_orig_pfns(buffer, &copy_bm);
if (error)
return error;
if (handle->prev == nr_meta_pages) {
error = prepare_image(&orig_bm, &copy_bm);
if (error)
return error;
chain_init(&ca, GFP_ATOMIC, PG_SAFE);
memory_bm_position_reset(&orig_bm);
restore_pblist = NULL;
handle->buffer = get_buffer(&orig_bm, &ca);
handle->sync_read = 0;
if (IS_ERR(handle->buffer))
return PTR_ERR(handle->buffer);
}
} else {
copy_last_highmem_page();
chain_init(&ca, GFP_ATOMIC, PG_SAFE);
memory_bm_position_reset(&orig_bm);
restore_pblist = NULL;
handle->buffer = get_buffer(&orig_bm, &ca);
handle->sync_read = 0;
if (IS_ERR(handle->buffer))
return PTR_ERR(handle->buffer);
if (handle->buffer != buffer)
handle->sync_read = 0;
}
handle->prev = handle->cur;
}
handle->buf_offset = handle->cur_offset;
if (handle->cur_offset + count >= PAGE_SIZE) {
count = PAGE_SIZE - handle->cur_offset;
handle->cur_offset = 0;
handle->cur++;
} else {
handle->cur_offset += count;
copy_last_highmem_page();
handle->buffer = get_buffer(&orig_bm, &ca);
if (IS_ERR(handle->buffer))
return PTR_ERR(handle->buffer);
if (handle->buffer != buffer)
handle->sync_read = 0;
}
handle->offset += count;
return count;
handle->cur++;
return PAGE_SIZE;
}
/**
@@ -2230,7 +2197,7 @@ void snapshot_write_finalize(struct snapshot_handle *handle)
{
copy_last_highmem_page();
/* Free only if we have loaded the image entirely */
if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) {
if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
free_highmem_data();
}

333
kernel/power/swap.c
View File

@@ -29,6 +29,40 @@
#define SWSUSP_SIG "S1SUSPEND"
/*
* The swap map is a data structure used for keeping track of each page
* written to a swap partition. It consists of many swap_map_page
* structures that contain each an array of MAP_PAGE_SIZE swap entries.
* These structures are stored on the swap and linked together with the
* help of the .next_swap member.
*
* The swap map is created during suspend. The swap map pages are
* allocated and populated one at a time, so we only need one memory
* page to set up the entire structure.
*
* During resume we also only need to use one swap_map_page structure
* at a time.
*/
#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
struct swap_map_page {
sector_t entries[MAP_PAGE_ENTRIES];
sector_t next_swap;
};
/**
* The swap_map_handle structure is used for handling swap in
* a file-alike way
*/
struct swap_map_handle {
struct swap_map_page *cur;
sector_t cur_swap;
sector_t first_sector;
unsigned int k;
};
struct swsusp_header {
char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)];
sector_t image;
@@ -145,110 +179,24 @@ int swsusp_swap_in_use(void)
*/
static unsigned short root_swap = 0xffff;
static struct block_device *resume_bdev;
/**
* submit - submit BIO request.
* @rw: READ or WRITE.
* @off physical offset of page.
* @page: page we're reading or writing.
* @bio_chain: list of pending biod (for async reading)
*
* Straight from the textbook - allocate and initialize the bio.
* If we're reading, make sure the page is marked as dirty.
* Then submit it and, if @bio_chain == NULL, wait.
*/
static int submit(int rw, pgoff_t page_off, struct page *page,
struct bio **bio_chain)
{
const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
struct bio *bio;
bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
bio->bi_sector = page_off * (PAGE_SIZE >> 9);
bio->bi_bdev = resume_bdev;
bio->bi_end_io = end_swap_bio_read;
if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
printk(KERN_ERR "PM: Adding page to bio failed at %ld\n",
page_off);
bio_put(bio);
return -EFAULT;
}
lock_page(page);
bio_get(bio);
if (bio_chain == NULL) {
submit_bio(bio_rw, bio);
wait_on_page_locked(page);
if (rw == READ)
bio_set_pages_dirty(bio);
bio_put(bio);
} else {
if (rw == READ)
get_page(page); /* These pages are freed later */
bio->bi_private = *bio_chain;
*bio_chain = bio;
submit_bio(bio_rw, bio);
}
return 0;
}
static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
{
return submit(READ, page_off, virt_to_page(addr), bio_chain);
}
static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
{
return submit(WRITE, page_off, virt_to_page(addr), bio_chain);
}
static int wait_on_bio_chain(struct bio **bio_chain)
{
struct bio *bio;
struct bio *next_bio;
int ret = 0;
if (bio_chain == NULL)
return 0;
bio = *bio_chain;
if (bio == NULL)
return 0;
while (bio) {
struct page *page;
next_bio = bio->bi_private;
page = bio->bi_io_vec[0].bv_page;
wait_on_page_locked(page);
if (!PageUptodate(page) || PageError(page))
ret = -EIO;
put_page(page);
bio_put(bio);
bio = next_bio;
}
*bio_chain = NULL;
return ret;
}
struct block_device *hib_resume_bdev;
/*
* Saving part
*/
static int mark_swapfiles(sector_t start, unsigned int flags)
static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
{
int error;
bio_read_page(swsusp_resume_block, swsusp_header, NULL);
hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
!memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
memcpy(swsusp_header->sig,SWSUSP_SIG, 10);
swsusp_header->image = start;
swsusp_header->image = handle->first_sector;
swsusp_header->flags = flags;
error = bio_write_page(swsusp_resume_block,
error = hib_bio_write_page(swsusp_resume_block,
swsusp_header, NULL);
} else {
printk(KERN_ERR "PM: Swap header not found!\n");
@@ -260,25 +208,26 @@ static int mark_swapfiles(sector_t start, unsigned int flags)
/**
* swsusp_swap_check - check if the resume device is a swap device
* and get its index (if so)
*
* This is called before saving image
*/
static int swsusp_swap_check(void) /* This is called before saving image */
static int swsusp_swap_check(void)
{
int res;
res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
&resume_bdev);
&hib_resume_bdev);
if (res < 0)
return res;
root_swap = res;
res = blkdev_get(resume_bdev, FMODE_WRITE);
res = blkdev_get(hib_resume_bdev, FMODE_WRITE);
if (res)
return res;
res = set_blocksize(resume_bdev, PAGE_SIZE);
res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
if (res < 0)
blkdev_put(resume_bdev, FMODE_WRITE);
blkdev_put(hib_resume_bdev, FMODE_WRITE);
return res;
}
@@ -309,42 +258,9 @@ static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
} else {
src = buf;
}
return bio_write_page(offset, src, bio_chain);
return hib_bio_write_page(offset, src, bio_chain);
}
/*
* The swap map is a data structure used for keeping track of each page
* written to a swap partition. It consists of many swap_map_page
* structures that contain each an array of MAP_PAGE_SIZE swap entries.
* These structures are stored on the swap and linked together with the
* help of the .next_swap member.
*
* The swap map is created during suspend. The swap map pages are
* allocated and populated one at a time, so we only need one memory
* page to set up the entire structure.
*
* During resume we also only need to use one swap_map_page structure
* at a time.
*/
#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
struct swap_map_page {
sector_t entries[MAP_PAGE_ENTRIES];
sector_t next_swap;
};
/**
* The swap_map_handle structure is used for handling swap in
* a file-alike way
*/
struct swap_map_handle {
struct swap_map_page *cur;
sector_t cur_swap;
unsigned int k;
};
static void release_swap_writer(struct swap_map_handle *handle)
{
if (handle->cur)
@@ -354,16 +270,33 @@ static void release_swap_writer(struct swap_map_handle *handle)
static int get_swap_writer(struct swap_map_handle *handle)
{
int ret;
ret = swsusp_swap_check();
if (ret) {
if (ret != -ENOSPC)
printk(KERN_ERR "PM: Cannot find swap device, try "
"swapon -a.\n");
return ret;
}
handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
if (!handle->cur)
return -ENOMEM;
if (!handle->cur) {
ret = -ENOMEM;
goto err_close;
}
handle->cur_swap = alloc_swapdev_block(root_swap);
if (!handle->cur_swap) {
release_swap_writer(handle);
return -ENOSPC;
ret = -ENOSPC;
goto err_rel;
}
handle->k = 0;
handle->first_sector = handle->cur_swap;
return 0;
err_rel:
release_swap_writer(handle);
err_close:
swsusp_close(FMODE_WRITE);
return ret;
}
static int swap_write_page(struct swap_map_handle *handle, void *buf,
@@ -380,7 +313,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
return error;
handle->cur->entries[handle->k++] = offset;
if (handle->k >= MAP_PAGE_ENTRIES) {
error = wait_on_bio_chain(bio_chain);
error = hib_wait_on_bio_chain(bio_chain);
if (error)
goto out;
offset = alloc_swapdev_block(root_swap);
@@ -406,6 +339,24 @@ static int flush_swap_writer(struct swap_map_handle *handle)
return -EINVAL;
}
static int swap_writer_finish(struct swap_map_handle *handle,
unsigned int flags, int error)
{
if (!error) {
flush_swap_writer(handle);
printk(KERN_INFO "PM: S");
error = mark_swapfiles(handle, flags);
printk("|\n");
}
if (error)
free_all_swap_pages(root_swap);
release_swap_writer(handle);
swsusp_close(FMODE_WRITE);
return error;
}
/**
* save_image - save the suspend image data
*/
@@ -431,7 +382,7 @@ static int save_image(struct swap_map_handle *handle,
bio = NULL;
do_gettimeofday(&start);
while (1) {
ret = snapshot_read_next(snapshot, PAGE_SIZE);
ret = snapshot_read_next(snapshot);
if (ret <= 0)
break;
ret = swap_write_page(handle, data_of(*snapshot), &bio);
@@ -441,7 +392,7 @@ static int save_image(struct swap_map_handle *handle,
printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m);
nr_pages++;
}
err2 = wait_on_bio_chain(&bio);
err2 = hib_wait_on_bio_chain(&bio);
do_gettimeofday(&stop);
if (!ret)
ret = err2;
@@ -483,50 +434,34 @@ int swsusp_write(unsigned int flags)
struct swap_map_handle handle;
struct snapshot_handle snapshot;
struct swsusp_info *header;
unsigned long pages;
int error;
error = swsusp_swap_check();
pages = snapshot_get_image_size();
error = get_swap_writer(&handle);
if (error) {
printk(KERN_ERR "PM: Cannot find swap device, try "
"swapon -a.\n");
printk(KERN_ERR "PM: Cannot get swap writer\n");
return error;
}
if (!enough_swap(pages)) {
printk(KERN_ERR "PM: Not enough free swap\n");
error = -ENOSPC;
goto out_finish;
}
memset(&snapshot, 0, sizeof(struct snapshot_handle));
error = snapshot_read_next(&snapshot, PAGE_SIZE);
error = snapshot_read_next(&snapshot);
if (error < PAGE_SIZE) {
if (error >= 0)
error = -EFAULT;
goto out;
goto out_finish;
}
header = (struct swsusp_info *)data_of(snapshot);
if (!enough_swap(header->pages)) {
printk(KERN_ERR "PM: Not enough free swap\n");
error = -ENOSPC;
goto out;
}
error = get_swap_writer(&handle);
if (!error) {
sector_t start = handle.cur_swap;
error = swap_write_page(&handle, header, NULL);
if (!error)
error = save_image(&handle, &snapshot,
header->pages - 1);
if (!error) {
flush_swap_writer(&handle);
printk(KERN_INFO "PM: S");
error = mark_swapfiles(start, flags);
printk("|\n");
}
}
if (error)
free_all_swap_pages(root_swap);
release_swap_writer(&handle);
out:
swsusp_close(FMODE_WRITE);
error = swap_write_page(&handle, header, NULL);
if (!error)
error = save_image(&handle, &snapshot, pages - 1);
out_finish:
error = swap_writer_finish(&handle, flags, error);
return error;
}
@@ -542,18 +477,21 @@ static void release_swap_reader(struct swap_map_handle *handle)
handle->cur = NULL;
}
static int get_swap_reader(struct swap_map_handle *handle, sector_t start)
static int get_swap_reader(struct swap_map_handle *handle,
unsigned int *flags_p)
{
int error;
if (!start)
*flags_p = swsusp_header->flags;
if (!swsusp_header->image) /* how can this happen? */
return -EINVAL;
handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH);
if (!handle->cur)
return -ENOMEM;
error = bio_read_page(start, handle->cur, NULL);
error = hib_bio_read_page(swsusp_header->image, handle->cur, NULL);
if (error) {
release_swap_reader(handle);
return error;
@@ -573,21 +511,28 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf,
offset = handle->cur->entries[handle->k];
if (!offset)
return -EFAULT;
error = bio_read_page(offset, buf, bio_chain);
error = hib_bio_read_page(offset, buf, bio_chain);
if (error)
return error;
if (++handle->k >= MAP_PAGE_ENTRIES) {
error = wait_on_bio_chain(bio_chain);
error = hib_wait_on_bio_chain(bio_chain);
handle->k = 0;
offset = handle->cur->next_swap;
if (!offset)
release_swap_reader(handle);
else if (!error)
error = bio_read_page(offset, handle->cur, NULL);
error = hib_bio_read_page(offset, handle->cur, NULL);
}
return error;
}
static int swap_reader_finish(struct swap_map_handle *handle)
{
release_swap_reader(handle);
return 0;
}
/**
* load_image - load the image using the swap map handle
* @handle and the snapshot handle @snapshot
@@ -615,21 +560,21 @@ static int load_image(struct swap_map_handle *handle,
bio = NULL;
do_gettimeofday(&start);
for ( ; ; ) {
error = snapshot_write_next(snapshot, PAGE_SIZE);
error = snapshot_write_next(snapshot);
if (error <= 0)
break;
error = swap_read_page(handle, data_of(*snapshot), &bio);
if (error)
break;
if (snapshot->sync_read)
error = wait_on_bio_chain(&bio);
error = hib_wait_on_bio_chain(&bio);
if (error)
break;
if (!(nr_pages % m))
printk("\b\b\b\b%3d%%", nr_pages / m);
nr_pages++;
}
err2 = wait_on_bio_chain(&bio);
err2 = hib_wait_on_bio_chain(&bio);
do_gettimeofday(&stop);
if (!error)
error = err2;
@@ -657,20 +602,20 @@ int swsusp_read(unsigned int *flags_p)
struct snapshot_handle snapshot;
struct swsusp_info *header;
*flags_p = swsusp_header->flags;
memset(&snapshot, 0, sizeof(struct snapshot_handle));
error = snapshot_write_next(&snapshot, PAGE_SIZE);
error = snapshot_write_next(&snapshot);
if (error < PAGE_SIZE)
return error < 0 ? error : -EFAULT;
header = (struct swsusp_info *)data_of(snapshot);
error = get_swap_reader(&handle, swsusp_header->image);
error = get_swap_reader(&handle, flags_p);
if (error)
goto end;
if (!error)
error = swap_read_page(&handle, header, NULL);
if (!error)
error = load_image(&handle, &snapshot, header->pages - 1);
release_swap_reader(&handle);
swap_reader_finish(&handle);
end:
if (!error)
pr_debug("PM: Image successfully loaded\n");
else
@@ -686,11 +631,11 @@ int swsusp_check(void)
{
int error;
resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
if (!IS_ERR(resume_bdev)) {
set_blocksize(resume_bdev, PAGE_SIZE);
hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
if (!IS_ERR(hib_resume_bdev)) {
set_blocksize(hib_resume_bdev, PAGE_SIZE);
memset(swsusp_header, 0, PAGE_SIZE);
error = bio_read_page(swsusp_resume_block,
error = hib_bio_read_page(swsusp_resume_block,
swsusp_header, NULL);
if (error)
goto put;
@@ -698,7 +643,7 @@ int swsusp_check(void)
if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
/* Reset swap signature now */
error = bio_write_page(swsusp_resume_block,
error = hib_bio_write_page(swsusp_resume_block,
swsusp_header, NULL);
} else {
error = -EINVAL;
@@ -706,11 +651,11 @@ int swsusp_check(void)
put:
if (error)
blkdev_put(resume_bdev, FMODE_READ);
blkdev_put(hib_resume_bdev, FMODE_READ);
else
pr_debug("PM: Signature found, resuming\n");
} else {
error = PTR_ERR(resume_bdev);
error = PTR_ERR(hib_resume_bdev);
}
if (error)
@@ -725,12 +670,12 @@ put:
void swsusp_close(fmode_t mode)
{
if (IS_ERR(resume_bdev)) {
if (IS_ERR(hib_resume_bdev)) {
pr_debug("PM: Image device not initialised\n");
return;
}
blkdev_put(resume_bdev, mode);
blkdev_put(hib_resume_bdev, mode);
}
static int swsusp_header_init(void)

37
kernel/power/user.c
View File

@@ -151,6 +151,7 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
{
struct snapshot_data *data;
ssize_t res;
loff_t pg_offp = *offp & ~PAGE_MASK;
mutex_lock(&pm_mutex);
@@ -159,14 +160,19 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
res = -ENODATA;
goto Unlock;
}
res = snapshot_read_next(&data->handle, count);
if (res > 0) {
if (copy_to_user(buf, data_of(data->handle), res))
res = -EFAULT;
else
*offp = data->handle.offset;
if (!pg_offp) { /* on page boundary? */
res = snapshot_read_next(&data->handle);
if (res <= 0)
goto Unlock;
} else {
res = PAGE_SIZE - pg_offp;
}
res = simple_read_from_buffer(buf, count, &pg_offp,
data_of(data->handle), res);
if (res > 0)
*offp += res;
Unlock:
mutex_unlock(&pm_mutex);
@@ -178,18 +184,25 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
{
struct snapshot_data *data;
ssize_t res;
loff_t pg_offp = *offp & ~PAGE_MASK;
mutex_lock(&pm_mutex);
data = filp->private_data;
res = snapshot_write_next(&data->handle, count);
if (res > 0) {
if (copy_from_user(data_of(data->handle), buf, res))
res = -EFAULT;
else
*offp = data->handle.offset;
if (!pg_offp) {
res = snapshot_write_next(&data->handle);
if (res <= 0)
goto unlock;
} else {
res = PAGE_SIZE - pg_offp;
}
res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
buf, count);
if (res > 0)
*offp += res;
unlock:
mutex_unlock(&pm_mutex);
return res;