PM / Hibernate: Snapshot cleanup
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> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
parent
6a727b43be
commit
d3c1b24c50
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@ -97,24 +97,12 @@ extern int hibernate_preallocate_memory(void);
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*/
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*/
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struct snapshot_handle {
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struct snapshot_handle {
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loff_t offset; /* number of the last byte ready for reading
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* or writing in the sequence
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*/
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unsigned int cur; /* number of the block of PAGE_SIZE bytes the
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unsigned int cur; /* number of the block of PAGE_SIZE bytes the
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* next operation will refer to (ie. current)
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* next operation will refer to (ie. current)
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*/
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*/
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unsigned int cur_offset; /* offset with respect to the current
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* block (for the next operation)
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*/
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unsigned int prev; /* number of the block of PAGE_SIZE bytes that
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* was the current one previously
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*/
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void *buffer; /* address of the block to read from
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void *buffer; /* address of the block to read from
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* or write to
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* or write to
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*/
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*/
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unsigned int buf_offset; /* location to read from or write to,
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* given as a displacement from 'buffer'
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*/
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int sync_read; /* Set to one to notify the caller of
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int sync_read; /* Set to one to notify the caller of
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* snapshot_write_next() that it may
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* snapshot_write_next() that it may
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* need to call wait_on_bio_chain()
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* need to call wait_on_bio_chain()
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@ -125,12 +113,12 @@ struct snapshot_handle {
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* snapshot_read_next()/snapshot_write_next() is allowed to
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* snapshot_read_next()/snapshot_write_next() is allowed to
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* read/write data after the function returns
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* read/write data after the function returns
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*/
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*/
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#define data_of(handle) ((handle).buffer + (handle).buf_offset)
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#define data_of(handle) ((handle).buffer)
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extern unsigned int snapshot_additional_pages(struct zone *zone);
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extern unsigned int snapshot_additional_pages(struct zone *zone);
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extern unsigned long snapshot_get_image_size(void);
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extern unsigned long snapshot_get_image_size(void);
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extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
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extern int snapshot_read_next(struct snapshot_handle *handle);
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extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
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extern int snapshot_write_next(struct snapshot_handle *handle);
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extern void snapshot_write_finalize(struct snapshot_handle *handle);
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extern void snapshot_write_finalize(struct snapshot_handle *handle);
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extern int snapshot_image_loaded(struct snapshot_handle *handle);
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extern int snapshot_image_loaded(struct snapshot_handle *handle);
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@ -1604,14 +1604,9 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
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* snapshot_handle structure. The structure gets updated and a pointer
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* snapshot_handle structure. The structure gets updated and a pointer
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* to it should be passed to this function every next time.
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* to it should be passed to this function every next time.
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*
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*
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* The @count parameter should contain the number of bytes the caller
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* wants to read from the snapshot. It must not be zero.
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*
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* On success the function returns a positive number. Then, the caller
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* On success the function returns a positive number. Then, the caller
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* is allowed to read up to the returned number of bytes from the memory
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* is allowed to read up to the returned number of bytes from the memory
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* location computed by the data_of() macro. The number returned
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* location computed by the data_of() macro.
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* may be smaller than @count, but this only happens if the read would
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* cross a page boundary otherwise.
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*
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*
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* The function returns 0 to indicate the end of data stream condition,
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* The function returns 0 to indicate the end of data stream condition,
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* and a negative number is returned on error. In such cases the
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* and a negative number is returned on error. In such cases the
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@ -1619,7 +1614,7 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
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* any more.
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* any more.
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*/
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*/
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int snapshot_read_next(struct snapshot_handle *handle, size_t count)
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int snapshot_read_next(struct snapshot_handle *handle)
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{
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{
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if (handle->cur > nr_meta_pages + nr_copy_pages)
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if (handle->cur > nr_meta_pages + nr_copy_pages)
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return 0;
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return 0;
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@ -1630,7 +1625,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
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if (!buffer)
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if (!buffer)
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return -ENOMEM;
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return -ENOMEM;
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}
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}
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if (!handle->offset) {
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if (!handle->cur) {
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int error;
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int error;
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error = init_header((struct swsusp_info *)buffer);
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error = init_header((struct swsusp_info *)buffer);
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@ -1639,9 +1634,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
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handle->buffer = buffer;
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handle->buffer = buffer;
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memory_bm_position_reset(&orig_bm);
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memory_bm_position_reset(&orig_bm);
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memory_bm_position_reset(©_bm);
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memory_bm_position_reset(©_bm);
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}
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} else if (handle->cur <= nr_meta_pages) {
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if (handle->prev < handle->cur) {
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if (handle->cur <= nr_meta_pages) {
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memset(buffer, 0, PAGE_SIZE);
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memset(buffer, 0, PAGE_SIZE);
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pack_pfns(buffer, &orig_bm);
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pack_pfns(buffer, &orig_bm);
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} else {
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} else {
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@ -1663,18 +1656,8 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
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handle->buffer = page_address(page);
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handle->buffer = page_address(page);
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}
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}
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}
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}
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handle->prev = handle->cur;
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}
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handle->buf_offset = handle->cur_offset;
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if (handle->cur_offset + count >= PAGE_SIZE) {
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count = PAGE_SIZE - handle->cur_offset;
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handle->cur_offset = 0;
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handle->cur++;
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handle->cur++;
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} else {
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return PAGE_SIZE;
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handle->cur_offset += count;
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}
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handle->offset += count;
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return count;
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}
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}
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/**
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/**
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@ -2133,14 +2116,9 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
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* snapshot_handle structure. The structure gets updated and a pointer
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* snapshot_handle structure. The structure gets updated and a pointer
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* to it should be passed to this function every next time.
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* to it should be passed to this function every next time.
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*
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*
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* The @count parameter should contain the number of bytes the caller
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* wants to write to the image. It must not be zero.
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*
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* On success the function returns a positive number. Then, the caller
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* On success the function returns a positive number. Then, the caller
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* is allowed to write up to the returned number of bytes to the memory
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* is allowed to write up to the returned number of bytes to the memory
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* location computed by the data_of() macro. The number returned
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* location computed by the data_of() macro.
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* may be smaller than @count, but this only happens if the write would
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* cross a page boundary otherwise.
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*
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*
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* The function returns 0 to indicate the "end of file" condition,
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* The function returns 0 to indicate the "end of file" condition,
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* and a negative number is returned on error. In such cases the
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* and a negative number is returned on error. In such cases the
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@ -2148,16 +2126,18 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
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* any more.
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* any more.
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*/
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*/
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int snapshot_write_next(struct snapshot_handle *handle, size_t count)
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int snapshot_write_next(struct snapshot_handle *handle)
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{
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{
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static struct chain_allocator ca;
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static struct chain_allocator ca;
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int error = 0;
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int error = 0;
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/* Check if we have already loaded the entire image */
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/* Check if we have already loaded the entire image */
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if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
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if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
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return 0;
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return 0;
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if (handle->offset == 0) {
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handle->sync_read = 1;
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if (!handle->cur) {
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if (!buffer)
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if (!buffer)
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/* This makes the buffer be freed by swsusp_free() */
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/* This makes the buffer be freed by swsusp_free() */
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buffer = get_image_page(GFP_ATOMIC, PG_ANY);
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buffer = get_image_page(GFP_ATOMIC, PG_ANY);
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@ -2166,10 +2146,7 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
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return -ENOMEM;
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return -ENOMEM;
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handle->buffer = buffer;
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handle->buffer = buffer;
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}
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} else if (handle->cur == 1) {
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handle->sync_read = 1;
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if (handle->prev < handle->cur) {
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if (handle->prev == 0) {
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error = load_header(buffer);
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error = load_header(buffer);
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if (error)
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if (error)
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return error;
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return error;
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@ -2178,12 +2155,12 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
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if (error)
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if (error)
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return error;
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return error;
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} else if (handle->prev <= nr_meta_pages) {
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} else if (handle->cur <= nr_meta_pages + 1) {
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error = unpack_orig_pfns(buffer, ©_bm);
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error = unpack_orig_pfns(buffer, ©_bm);
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if (error)
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if (error)
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return error;
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return error;
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if (handle->prev == nr_meta_pages) {
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if (handle->cur == nr_meta_pages + 1) {
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error = prepare_image(&orig_bm, ©_bm);
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error = prepare_image(&orig_bm, ©_bm);
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if (error)
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if (error)
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return error;
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return error;
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@ -2204,18 +2181,8 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
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if (handle->buffer != buffer)
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if (handle->buffer != buffer)
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handle->sync_read = 0;
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handle->sync_read = 0;
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}
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}
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handle->prev = handle->cur;
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}
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handle->buf_offset = handle->cur_offset;
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if (handle->cur_offset + count >= PAGE_SIZE) {
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count = PAGE_SIZE - handle->cur_offset;
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handle->cur_offset = 0;
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handle->cur++;
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handle->cur++;
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} else {
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return PAGE_SIZE;
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handle->cur_offset += count;
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}
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handle->offset += count;
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return count;
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}
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}
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/**
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/**
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@ -2230,7 +2197,7 @@ void snapshot_write_finalize(struct snapshot_handle *handle)
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{
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{
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copy_last_highmem_page();
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copy_last_highmem_page();
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/* Free only if we have loaded the image entirely */
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/* Free only if we have loaded the image entirely */
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if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) {
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if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
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memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
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memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
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free_highmem_data();
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free_highmem_data();
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}
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}
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@ -431,7 +431,7 @@ static int save_image(struct swap_map_handle *handle,
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bio = NULL;
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bio = NULL;
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do_gettimeofday(&start);
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do_gettimeofday(&start);
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while (1) {
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while (1) {
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ret = snapshot_read_next(snapshot, PAGE_SIZE);
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ret = snapshot_read_next(snapshot);
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if (ret <= 0)
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if (ret <= 0)
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break;
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break;
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ret = swap_write_page(handle, data_of(*snapshot), &bio);
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ret = swap_write_page(handle, data_of(*snapshot), &bio);
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@ -492,7 +492,7 @@ int swsusp_write(unsigned int flags)
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return error;
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return error;
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}
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}
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memset(&snapshot, 0, sizeof(struct snapshot_handle));
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memset(&snapshot, 0, sizeof(struct snapshot_handle));
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error = snapshot_read_next(&snapshot, PAGE_SIZE);
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error = snapshot_read_next(&snapshot);
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if (error < PAGE_SIZE) {
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if (error < PAGE_SIZE) {
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if (error >= 0)
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if (error >= 0)
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error = -EFAULT;
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error = -EFAULT;
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@ -615,7 +615,7 @@ static int load_image(struct swap_map_handle *handle,
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bio = NULL;
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bio = NULL;
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do_gettimeofday(&start);
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do_gettimeofday(&start);
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for ( ; ; ) {
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for ( ; ; ) {
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error = snapshot_write_next(snapshot, PAGE_SIZE);
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error = snapshot_write_next(snapshot);
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if (error <= 0)
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if (error <= 0)
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break;
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break;
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error = swap_read_page(handle, data_of(*snapshot), &bio);
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error = swap_read_page(handle, data_of(*snapshot), &bio);
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@ -660,7 +660,7 @@ int swsusp_read(unsigned int *flags_p)
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*flags_p = swsusp_header->flags;
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*flags_p = swsusp_header->flags;
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memset(&snapshot, 0, sizeof(struct snapshot_handle));
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memset(&snapshot, 0, sizeof(struct snapshot_handle));
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error = snapshot_write_next(&snapshot, PAGE_SIZE);
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error = snapshot_write_next(&snapshot);
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if (error < PAGE_SIZE)
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if (error < PAGE_SIZE)
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return error < 0 ? error : -EFAULT;
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return error < 0 ? error : -EFAULT;
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header = (struct swsusp_info *)data_of(snapshot);
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header = (struct swsusp_info *)data_of(snapshot);
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@ -151,6 +151,7 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
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{
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{
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struct snapshot_data *data;
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struct snapshot_data *data;
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ssize_t res;
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ssize_t res;
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loff_t pg_offp = *offp & ~PAGE_MASK;
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mutex_lock(&pm_mutex);
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mutex_lock(&pm_mutex);
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@ -159,14 +160,19 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
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res = -ENODATA;
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res = -ENODATA;
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goto Unlock;
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goto Unlock;
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}
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}
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res = snapshot_read_next(&data->handle, count);
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if (!pg_offp) { /* on page boundary? */
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if (res > 0) {
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res = snapshot_read_next(&data->handle);
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if (copy_to_user(buf, data_of(data->handle), res))
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if (res <= 0)
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res = -EFAULT;
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goto Unlock;
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else
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} else {
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*offp = data->handle.offset;
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res = PAGE_SIZE - pg_offp;
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}
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}
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res = simple_read_from_buffer(buf, count, &pg_offp,
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data_of(data->handle), res);
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if (res > 0)
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*offp += res;
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Unlock:
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Unlock:
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mutex_unlock(&pm_mutex);
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mutex_unlock(&pm_mutex);
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@ -178,18 +184,25 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
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{
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{
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struct snapshot_data *data;
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struct snapshot_data *data;
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ssize_t res;
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ssize_t res;
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loff_t pg_offp = *offp & ~PAGE_MASK;
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mutex_lock(&pm_mutex);
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mutex_lock(&pm_mutex);
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data = filp->private_data;
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data = filp->private_data;
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res = snapshot_write_next(&data->handle, count);
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if (res > 0) {
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if (!pg_offp) {
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if (copy_from_user(data_of(data->handle), buf, res))
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res = snapshot_write_next(&data->handle);
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res = -EFAULT;
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if (res <= 0)
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else
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goto unlock;
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*offp = data->handle.offset;
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} else {
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res = PAGE_SIZE - pg_offp;
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}
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}
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res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
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buf, count);
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if (res > 0)
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*offp += res;
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unlock:
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mutex_unlock(&pm_mutex);
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mutex_unlock(&pm_mutex);
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return res;
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return res;
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