[PATCH 1/5] FS: libfs, implement simple_write_to_buffer

[PATCH 1/5] FS: libfs, implement simple_write_to_buffer

[Jiri Slaby]

It will be used in suspend code and serves as an easy wrap around
copy_from_user. Similar to simple_read_from_buffer, it takes care
of transfers with proper lengths depending on available and count
parameters and advances ppos appropriately.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Nigel Cunningham <ncunningham@crca.org.au>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
---
 fs/libfs.c         |   35 +++++++++++++++++++++++++++++++++++
 include/linux/fs.h |    2 ++
 2 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index ea9a6cc..cfab42a 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -547,6 +547,40 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
 }
 
 /**
+ * simple_write_to_buffer - copy data from user space to the buffer
+ * @to: the buffer to write to
+ * @available: the size of the buffer
+ * @ppos: the current position in the buffer
+ * @from: the user space buffer to read from
+ * @count: the maximum number of bytes to read
+ *
+ * The simple_write_to_buffer() function reads up to @count bytes from the user
+ * space address starting at @from into the buffer @to at offset @ppos.
+ *
+ * On success, the number of bytes written is returned and the offset @ppos is
+ * advanced by this number, or negative value is returned on error.
+ **/
+ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
+		const void __user *from, size_t count)
+{
+	loff_t pos = *ppos;
+	size_t ret;
+
+	if (pos < 0)
+		return -EINVAL;
+	if (pos >= available || !count)
+		return 0;
+	if (count > available - pos)
+		count = available - pos;
+	ret = copy_from_user(to + pos, from, count);
+	if (ret == count)
+		return -EFAULT;
+	count -= ret;
+	*ppos = pos + count;
+	return count;
+}
+
+/**
  * memory_read_from_buffer - copy data from the buffer
  * @to: the kernel space buffer to read to
  * @count: the maximum number of bytes to read
@@ -864,6 +898,7 @@ EXPORT_SYMBOL(simple_statfs);
 EXPORT_SYMBOL(simple_sync_file);
 EXPORT_SYMBOL(simple_unlink);
 EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(simple_write_to_buffer);
 EXPORT_SYMBOL(memory_read_from_buffer);
 EXPORT_SYMBOL(simple_transaction_set);
 EXPORT_SYMBOL(simple_transaction_get);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 66f3caa..e594a8d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2372,6 +2372,8 @@ extern void simple_release_fs(struct vfsmount **mount, int *count);
 
 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
 			loff_t *ppos, const void *from, size_t available);
+extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
+		const void __user *from, size_t count);
 
 extern int simple_fsync(struct file *, struct dentry *, int);
 
-- 
1.7.0.3

[PATCH 2/5] PM / Hibernate: snapshot cleanup

[Jiri Slaby]

From: Jiri Slaby <jirislaby@gmail.com>

Remove support of reads with offset. This means snapshot_read/write_next
now does not accept count parameter. It allows to clean up the functions
and snapshot handle which no longer needs to care about offsets.

/dev/snapshot handler is converted to simple_{read_from,write_to}_buffer
which take care of offsets.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Nigel Cunningham <ncunningham@crca.org.au>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
---
 kernel/power/power.h    |   18 +-----
 kernel/power/snapshot.c |  145 ++++++++++++++++++-----------------------------
 kernel/power/swap.c     |    8 +-
 kernel/power/user.c     |   37 ++++++++----
 4 files changed, 88 insertions(+), 120 deletions(-)

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 46c5a26..b1e207d 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -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);
 
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index be861c2..25ce010 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -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;
+	} else 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;
+		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);
-			}
+			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 {
-		handle->cur_offset += count;
 	}
-	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);
-			if (error)
-				return error;
+	} 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;
+		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;
 
-		} else if (handle->prev <= nr_meta_pages) {
-			error = unpack_orig_pfns(buffer, &copy_bm);
+		if (handle->cur == nr_meta_pages + 1) {
+			error = prepare_image(&orig_bm, &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();
 	}
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 66824d7..7f2a17e 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -431,7 +431,7 @@ 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);
@@ -492,7 +492,7 @@ int swsusp_write(unsigned int flags)
 		return error;
 	}
 	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;
@@ -615,7 +615,7 @@ 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);
@@ -660,7 +660,7 @@ int swsusp_read(unsigned int *flags_p)
 	*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);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index a8c9621..e819e17 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -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;
-- 
1.7.0.3

[PATCH 3/5] PM / Hibernate: separate block_io

[Jiri Slaby]

Move block I/O operations to a separate file. It is because it will
be used later not only by the swap writer.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Nigel Cunningham <ncunningham@crca.org.au>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
---
 kernel/power/Makefile   |    3 +-
 kernel/power/block_io.c |  103 +++++++++++++++++++++++++++++++++++
 kernel/power/power.h    |    9 +++
 kernel/power/swap.c     |  136 +++++++++--------------------------------------
 4 files changed, 139 insertions(+), 112 deletions(-)
 create mode 100644 kernel/power/block_io.c

diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 4319181..524e058 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -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
diff --git a/kernel/power/block_io.c b/kernel/power/block_io.c
new file mode 100644
index 0000000..3ba57e0
--- /dev/null
+++ b/kernel/power/block_io.c
@@ -0,0 +1,103 @@
+/*
+ * This file provides functions for block I/O operations on swap/file.
+ *
+ * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.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 %ld\n",
+			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;
+}
diff --git a/kernel/power/power.h b/kernel/power/power.h
index b1e207d..006270f 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -142,6 +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 *,
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 7f2a17e..1b1ab6f 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -145,93 +145,7 @@ 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
@@ -241,14 +155,14 @@ static int mark_swapfiles(sector_t start, 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->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");
@@ -267,18 +181,18 @@ static int swsusp_swap_check(void) /* This is called before saving image */
 	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;
 }
@@ -309,7 +223,7 @@ 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);
 }
 
 /*
@@ -380,7 +294,7 @@ 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);
@@ -441,7 +355,7 @@ 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;
@@ -553,7 +467,7 @@ static int get_swap_reader(struct swap_map_handle *handle, sector_t start)
 	if (!handle->cur)
 		return -ENOMEM;
 
-	error = bio_read_page(start, handle->cur, NULL);
+	error = hib_bio_read_page(start, handle->cur, NULL);
 	if (error) {
 		release_swap_reader(handle);
 		return error;
@@ -573,17 +487,17 @@ 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;
 }
@@ -622,14 +536,14 @@ static int load_image(struct swap_map_handle *handle,
 		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;
@@ -686,11 +600,11 @@ 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 +612,7 @@ 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 +620,11 @@ 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 +639,12 @@ 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)
-- 
1.7.0.3

[PATCH 4/5] PM / Hibernate: move the first_sector out of swsusp_write

[Jiri Slaby]

From: Jiri Slaby <jirislaby@gmail.com>

The first sector knowledge is swap-only specific. Move it into the
swap handle. This will be needed for later non-swap specific code
moving into snapshot.c.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Nigel Cunningham <ncunningham@crca.org.au>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 kernel/power/swap.c |   76 +++++++++++++++++++++++++-------------------------
 1 files changed, 38 insertions(+), 38 deletions(-)

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 1b1ab6f..63e8062 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -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;
@@ -151,7 +185,7 @@ 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;
 
@@ -160,7 +194,7 @@ static int mark_swapfiles(sector_t start, unsigned int flags)
 	    !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 = hib_bio_write_page(swsusp_resume_block,
 					swsusp_header, NULL);
@@ -226,39 +260,6 @@ static int write_page(void *buf, sector_t offset, struct bio **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)
@@ -277,6 +278,7 @@ static int get_swap_writer(struct swap_map_handle *handle)
 		return -ENOSPC;
 	}
 	handle->k = 0;
+	handle->first_sector = handle->cur_swap;
 	return 0;
 }
 
@@ -421,8 +423,6 @@ int swsusp_write(unsigned int flags)
 	}
 	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,
@@ -431,7 +431,7 @@ int swsusp_write(unsigned int flags)
 		if (!error) {
 			flush_swap_writer(&handle);
 			printk(KERN_INFO "PM: S");
-			error = mark_swapfiles(start, flags);
+			error = mark_swapfiles(&handle, flags);
 			printk("|\n");
 		}
 	}
-- 
1.7.0.3

[PATCH 5/5] PM / Hibernate: group swap ops

[Jiri Slaby]

Move all the swap processing into one function. It will make swap
calls from a non-swap code easier.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Nigel Cunningham <ncunningham@crca.org.au>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
---
 kernel/power/swap.c |  117 ++++++++++++++++++++++++++++++++-------------------
 1 files changed, 74 insertions(+), 43 deletions(-)

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 63e8062..b0bb217 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -208,9 +208,10 @@ static int mark_swapfiles(struct swap_map_handle *handle, 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;
 
@@ -269,17 +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,
@@ -322,6 +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
  */
@@ -399,48 +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);
 	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) {
-		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(&handle, 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;
 }
 
@@ -456,18 +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 = hib_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;
@@ -502,6 +526,13 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf,
 	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
@@ -571,20 +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);
 	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
-- 
1.7.0.3

Re: [PATCH 1/5] FS: libfs, implement simple_write_to_buffer

[Rafael J. Wysocki]

On Tuesday 27 April 2010, Jiri Slaby wrote:
> It will be used in suspend code and serves as an easy wrap around
> copy_from_user. Similar to simple_read_from_buffer, it takes care
> of transfers with proper lengths depending on available and count
> parameters and advances ppos appropriately.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Nigel Cunningham <ncunningham@crca.org.au>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: linux-fsdevel@vger.kernel.org

Thanks for the patches, I'll review them as soon as I can.

Rafael

Re: [PATCH 2/5] PM / Hibernate: snapshot cleanup

[Pavel Machek]

On Tue 2010-04-27 10:15:15, Jiri Slaby wrote:
> From: Jiri Slaby <jirislaby@gmail.com>
> 
> Remove support of reads with offset. This means snapshot_read/write_next
> now does not accept count parameter. It allows to clean up the functions
> and snapshot handle which no longer needs to care about offsets.
> 
> /dev/snapshot handler is converted to simple_{read_from,write_to}_buffer
> which take care of offsets.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Nigel Cunningham <ncunningham@crca.org.au>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>

ack.

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH 3/5] PM / Hibernate: separate block_io

[Pavel Machek]

Hi!

> Move block I/O operations to a separate file. It is because it will
> be used later not only by the swap writer.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Nigel Cunningham <ncunningham@crca.org.au>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>

> +++ b/kernel/power/block_io.c
> @@ -0,0 +1,103 @@
> +/*
> + * This file provides functions for block I/O operations on swap/file.
> + *
> + * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>

That address no longer works, but keeps popping up....

> diff --git a/kernel/power/power.h b/kernel/power/power.h
> index b1e207d..006270f 100644
> --- a/kernel/power/power.h
> +++ b/kernel/power/power.h
> @@ -142,6 +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;

It is slightly sad that this is now not only static, but also
cross-module...


> +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);
> +

Does the documentation usually go to the header in these cases?

								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH 1/5] FS: libfs, implement simple_write_to_buffer

[Rafael J. Wysocki]

On Tuesday 27 April 2010, Jiri Slaby wrote:
> It will be used in suspend code and serves as an easy wrap around
> copy_from_user. Similar to simple_read_from_buffer, it takes care
> of transfers with proper lengths depending on available and count
> parameters and advances ppos appropriately.

Will anyone object if I take this one into the suspend-2.6 tree?

Rafael


> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Nigel Cunningham <ncunningham@crca.org.au>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: linux-fsdevel@vger.kernel.org
> ---
>  fs/libfs.c         |   35 +++++++++++++++++++++++++++++++++++
>  include/linux/fs.h |    2 ++
>  2 files changed, 37 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/libfs.c b/fs/libfs.c
> index ea9a6cc..cfab42a 100644
> --- a/fs/libfs.c
> +++ b/fs/libfs.c
> @@ -547,6 +547,40 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
>  }
>  
>  /**
> + * simple_write_to_buffer - copy data from user space to the buffer
> + * @to: the buffer to write to
> + * @available: the size of the buffer
> + * @ppos: the current position in the buffer
> + * @from: the user space buffer to read from
> + * @count: the maximum number of bytes to read
> + *
> + * The simple_write_to_buffer() function reads up to @count bytes from the user
> + * space address starting at @from into the buffer @to at offset @ppos.
> + *
> + * On success, the number of bytes written is returned and the offset @ppos is
> + * advanced by this number, or negative value is returned on error.
> + **/
> +ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
> +		const void __user *from, size_t count)
> +{
> +	loff_t pos = *ppos;
> +	size_t ret;
> +
> +	if (pos < 0)
> +		return -EINVAL;
> +	if (pos >= available || !count)
> +		return 0;
> +	if (count > available - pos)
> +		count = available - pos;
> +	ret = copy_from_user(to + pos, from, count);
> +	if (ret == count)
> +		return -EFAULT;
> +	count -= ret;
> +	*ppos = pos + count;
> +	return count;
> +}
> +
> +/**
>   * memory_read_from_buffer - copy data from the buffer
>   * @to: the kernel space buffer to read to
>   * @count: the maximum number of bytes to read
> @@ -864,6 +898,7 @@ EXPORT_SYMBOL(simple_statfs);
>  EXPORT_SYMBOL(simple_sync_file);
>  EXPORT_SYMBOL(simple_unlink);
>  EXPORT_SYMBOL(simple_read_from_buffer);
> +EXPORT_SYMBOL(simple_write_to_buffer);
>  EXPORT_SYMBOL(memory_read_from_buffer);
>  EXPORT_SYMBOL(simple_transaction_set);
>  EXPORT_SYMBOL(simple_transaction_get);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 66f3caa..e594a8d 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2372,6 +2372,8 @@ extern void simple_release_fs(struct vfsmount **mount, int *count);
>  
>  extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
>  			loff_t *ppos, const void *from, size_t available);
> +extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
> +		const void __user *from, size_t count);
>  
>  extern int simple_fsync(struct file *, struct dentry *, int);
>  
> 

Re: [PATCH 1/5] FS: libfs, implement simple_write_to_buffer

[Rafael J. Wysocki]

On Tuesday 27 April 2010, Rafael J. Wysocki wrote:
> On Tuesday 27 April 2010, Jiri Slaby wrote:
> > It will be used in suspend code and serves as an easy wrap around
> > copy_from_user. Similar to simple_read_from_buffer, it takes care
> > of transfers with proper lengths depending on available and count
> > parameters and advances ppos appropriately.
> > 
> > Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> > Cc: Nigel Cunningham <ncunningham@crca.org.au>
> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> > Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> > Cc: linux-fsdevel@vger.kernel.org
> 
> Thanks for the patches, I'll review them as soon as I can.

They look good.  If there are no objections from the other people, I'll add
them to suspend-2.6/linux-next in the next few days.

Rafael

Re: [PATCH 3/5] PM / Hibernate: separate block_io

[Jiri Slaby]

On 04/28/2010 07:52 AM, Pavel Machek wrote:
>> + * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
> 
> That address no longer works, but keeps popping up....

Oops, it's a cut&paste from swap.c:
$ grep -r pavel.*suse kernel/power/
kernel/power/snapshot.c: * Copyright (C) 1998-2005 Pavel Machek
<pavel@suse.cz>
kernel/power/swap.c: * Copyright (C) 1998,2001-2005 Pavel Machek
<pavel@suse.cz>
kernel/power/hibernate.c: * Copyright (c) 2004 Pavel Machek <pavel@suse.cz>

-- 
js

Re: [PATCH 1/5] FS: libfs, implement simple_write_to_buffer

[Rafael J. Wysocki]

On Thursday 29 April 2010, Rafael J. Wysocki wrote:
> On Tuesday 27 April 2010, Rafael J. Wysocki wrote:
> > On Tuesday 27 April 2010, Jiri Slaby wrote:
> > > It will be used in suspend code and serves as an easy wrap around
> > > copy_from_user. Similar to simple_read_from_buffer, it takes care
> > > of transfers with proper lengths depending on available and count
> > > parameters and advances ppos appropriately.
> > > 
> > > Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> > > Cc: Nigel Cunningham <ncunningham@crca.org.au>
> > > Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> > > Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> > > Cc: linux-fsdevel@vger.kernel.org
> > 
> > Thanks for the patches, I'll review them as soon as I can.
> 
> They look good.  If there are no objections from the other people, I'll add
> them to suspend-2.6/linux-next in the next few days.

All patches in this series applied to suspend-2.6/linux-next.

I fixed up the Pavel's address in the copyright notice in kernel/power/block_io.c.

Thanks,
Rafael