From d3c1b24c50e8b2bbc840322caf26c7eada594d21 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Sat, 1 May 2010 23:52:02 +0200 Subject: 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 Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki --- 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(-) (limited to 'kernel') diff --git a/kernel/power/power.h b/kernel/power/power.h index 46c5a26630a3..b1e207dde1c2 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 be861c26dda7..25ce010e9f8b 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(©_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(©_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(©_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(©_bm, GFP_ATOMIC, PG_ANY); - if (error) - return error; + error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); + if (error) + return error; + + } else if (handle->cur <= nr_meta_pages + 1) { + error = unpack_orig_pfns(buffer, ©_bm); + if (error) + return error; - } else if (handle->prev <= nr_meta_pages) { - error = unpack_orig_pfns(buffer, ©_bm); + if (handle->cur == nr_meta_pages + 1) { + error = prepare_image(&orig_bm, ©_bm); if (error) return error; - if (handle->prev == nr_meta_pages) { - error = prepare_image(&orig_bm, ©_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 66824d71983a..7f2a17e4067b 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 a8c96212bc1b..e819e17877ca 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; -- cgit v1.2.3