suspend: simplify block I/O handling

Stop abusing struct page functionality and the swap end_io handler, and
instead add a modified version of the blk-lib.c bio_batch helpers.

Also move the block I/O code into swap.c as they are directly tied into
each other.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Ming Lin <mlin@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/include/linux/swap.h b/include/linux/swap.h
index cee108cbe2d52e15ada2c399a800145797e37eff..38874729dc5fd8989af223debcb9bd0ddb86199c 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -377,7 +377,6 @@ extern void end_swap_bio_write(struct bio *bio, int err);
 extern int __swap_writepage(struct page *page, struct writeback_control *wbc,
        void (*end_write_func)(struct bio *, int));
 extern int swap_set_page_dirty(struct page *page);
-extern void end_swap_bio_read(struct bio *bio, int err);
 
 int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
                unsigned long nr_pages, sector_t start_block);

diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 29472bff11ef9b1c902e71a7ae9823a9e36c06e6..cb880a14cc396eec6af959007011fd6830b14baa 100644 (file)
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -7,8 +7,7 @@ obj-$(CONFIG_VT_CONSOLE_SLEEP)  += console.o
 obj-$(CONFIG_FREEZER)          += process.o
 obj-$(CONFIG_SUSPEND)          += suspend.o
 obj-$(CONFIG_PM_TEST_SUSPEND)  += suspend_test.o
-obj-$(CONFIG_HIBERNATION)      += hibernate.o snapshot.o swap.o user.o \
-                                  block_io.o
+obj-$(CONFIG_HIBERNATION)      += hibernate.o snapshot.o swap.o user.o
 obj-$(CONFIG_PM_AUTOSLEEP)     += autosleep.o
 obj-$(CONFIG_PM_WAKELOCKS)     += wakelock.o
 

diff --git a/kernel/power/block_io.c b/kernel/power/block_io.c
deleted file mode 100644 (file)
index 9a58bc2..0000000
--- a/kernel/power/block_io.c
+++ /dev/null
@@ -1,103 +0,0 @@
-/*
- * This file provides functions for block I/O operations on swap/file.
- *
- * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
- * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
- *
- * This file is released under the GPLv2.
- */
-
-#include <linux/bio.h>
-#include <linux/kernel.h>
-#include <linux/pagemap.h>
-#include <linux/swap.h>
-
-#include "power.h"
-
-/**
- *     submit - submit BIO request.
- *     @rw:    READ or WRITE.
- *     @off    physical offset of page.
- *     @page:  page we're reading or writing.
- *     @bio_chain: list of pending biod (for async reading)
- *
- *     Straight from the textbook - allocate and initialize the bio.
- *     If we're reading, make sure the page is marked as dirty.
- *     Then submit it and, if @bio_chain == NULL, wait.
- */
-static int submit(int rw, struct block_device *bdev, sector_t sector,
-               struct page *page, struct bio **bio_chain)
-{
-       const int bio_rw = rw | REQ_SYNC;
-       struct bio *bio;
-
-       bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
-       bio->bi_iter.bi_sector = sector;
-       bio->bi_bdev = bdev;
-       bio->bi_end_io = end_swap_bio_read;
-
-       if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
-               printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
-                       (unsigned long long)sector);
-               bio_put(bio);
-               return -EFAULT;
-       }
-
-       lock_page(page);
-       bio_get(bio);
-
-       if (bio_chain == NULL) {
-               submit_bio(bio_rw, bio);
-               wait_on_page_locked(page);
-               if (rw == READ)
-                       bio_set_pages_dirty(bio);
-               bio_put(bio);
-       } else {
-               if (rw == READ)
-                       get_page(page); /* These pages are freed later */
-               bio->bi_private = *bio_chain;
-               *bio_chain = bio;
-               submit_bio(bio_rw, bio);
-       }
-       return 0;
-}
-
-int hib_bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
-{
-       return submit(READ, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
-                       virt_to_page(addr), bio_chain);
-}
-
-int hib_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
-{
-       return submit(WRITE, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
-                       virt_to_page(addr), bio_chain);
-}
-
-int hib_wait_on_bio_chain(struct bio **bio_chain)
-{
-       struct bio *bio;
-       struct bio *next_bio;
-       int ret = 0;
-
-       if (bio_chain == NULL)
-               return 0;
-
-       bio = *bio_chain;
-       if (bio == NULL)
-               return 0;
-       while (bio) {
-               struct page *page;
-
-               next_bio = bio->bi_private;
-               page = bio->bi_io_vec[0].bv_page;
-               wait_on_page_locked(page);
-               if (!PageUptodate(page) || PageError(page))
-                       ret = -EIO;
-               put_page(page);
-               bio_put(bio);
-               bio = next_bio;
-       }
-       *bio_chain = NULL;
-       return ret;
-}

diff --git a/kernel/power/power.h b/kernel/power/power.h
index ce9b8328a689111ca26c1ed5e46c95b58de7fb6e..caadb566e82bb51a5348d6ba67a73bda8c99f37d 100644 (file)
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -163,15 +163,6 @@ extern void swsusp_close(fmode_t);
 extern int swsusp_unmark(void);
 #endif
 
-/* 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(ktime_t, ktime_t, unsigned int, char *);

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 570aff817543fc8484b08ecdba09da4751acf060..2f30ca91e4fadfa7fa91cc8e62bf1ac7b9e35556 100644 (file)
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -212,7 +212,84 @@ int swsusp_swap_in_use(void)
  */
 
 static unsigned short root_swap = 0xffff;
-struct block_device *hib_resume_bdev;
+static struct block_device *hib_resume_bdev;
+
+struct hib_bio_batch {
+       atomic_t                count;
+       wait_queue_head_t       wait;
+       int                     error;
+};
+
+static void hib_init_batch(struct hib_bio_batch *hb)
+{
+       atomic_set(&hb->count, 0);
+       init_waitqueue_head(&hb->wait);
+       hb->error = 0;
+}
+
+static void hib_end_io(struct bio *bio, int error)
+{
+       struct hib_bio_batch *hb = bio->bi_private;
+       const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+       struct page *page = bio->bi_io_vec[0].bv_page;
+
+       if (!uptodate || error) {
+               printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
+                               imajor(bio->bi_bdev->bd_inode),
+                               iminor(bio->bi_bdev->bd_inode),
+                               (unsigned long long)bio->bi_iter.bi_sector);
+
+               if (!error)
+                       error = -EIO;
+       }
+
+       if (bio_data_dir(bio) == WRITE)
+               put_page(page);
+
+       if (error && !hb->error)
+               hb->error = error;
+       if (atomic_dec_and_test(&hb->count))
+               wake_up(&hb->wait);
+
+       bio_put(bio);
+}
+
+static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
+               struct hib_bio_batch *hb)
+{
+       struct page *page = virt_to_page(addr);
+       struct bio *bio;
+       int error = 0;
+
+       bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
+       bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
+       bio->bi_bdev = hib_resume_bdev;
+
+       if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+               printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
+                       (unsigned long long)bio->bi_iter.bi_sector);
+               bio_put(bio);
+               return -EFAULT;
+       }
+
+       if (hb) {
+               bio->bi_end_io = hib_end_io;
+               bio->bi_private = hb;
+               atomic_inc(&hb->count);
+               submit_bio(rw, bio);
+       } else {
+               error = submit_bio_wait(rw, bio);
+               bio_put(bio);
+       }
+
+       return error;
+}
+
+static int hib_wait_io(struct hib_bio_batch *hb)
+{
+       wait_event(hb->wait, atomic_read(&hb->count) == 0);
+       return hb->error;
+}
 
 /*
  * Saving part
@@ -222,7 +299,7 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 {
        int error;
 
-       hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
+       hib_submit_io(READ_SYNC, 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);
@@ -231,7 +308,7 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
                swsusp_header->flags = flags;
                if (flags & SF_CRC32_MODE)
                        swsusp_header->crc32 = handle->crc32;
-               error = hib_bio_write_page(swsusp_resume_block,
+               error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
                                        swsusp_header, NULL);
        } else {
                printk(KERN_ERR "PM: Swap header not found!\n");
@@ -271,10 +348,10 @@ static int swsusp_swap_check(void)
  *     write_page - Write one page to given swap location.
  *     @buf:           Address we're writing.
  *     @offset:        Offset of the swap page we're writing to.
- *     @bio_chain:     Link the next write BIO here
+ *     @hb:            bio completion batch
  */
 
-static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
+static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 {
        void *src;
        int ret;
@@ -282,13 +359,13 @@ static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
        if (!offset)
                return -ENOSPC;
 
-       if (bio_chain) {
+       if (hb) {
                src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
                                              __GFP_NORETRY);
                if (src) {
                        copy_page(src, buf);
                } else {
-                       ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
+                       ret = hib_wait_io(hb); /* Free pages */
                        if (ret)
                                return ret;
                        src = (void *)__get_free_page(__GFP_WAIT |
@@ -298,14 +375,14 @@ static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
                                copy_page(src, buf);
                        } else {
                                WARN_ON_ONCE(1);
-                               bio_chain = NULL;       /* Go synchronous */
+                               hb = NULL;      /* Go synchronous */
                                src = buf;
                        }
                }
        } else {
                src = buf;
        }
-       return hib_bio_write_page(offset, src, bio_chain);
+       return hib_submit_io(WRITE_SYNC, offset, src, hb);
 }
 
 static void release_swap_writer(struct swap_map_handle *handle)
@@ -348,7 +425,7 @@ err_close:
 }
 
 static int swap_write_page(struct swap_map_handle *handle, void *buf,
-                               struct bio **bio_chain)
+               struct hib_bio_batch *hb)
 {
        int error = 0;
        sector_t offset;
@@ -356,7 +433,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
        if (!handle->cur)
                return -EINVAL;
        offset = alloc_swapdev_block(root_swap);
-       error = write_page(buf, offset, bio_chain);
+       error = write_page(buf, offset, hb);
        if (error)
                return error;
        handle->cur->entries[handle->k++] = offset;
@@ -365,15 +442,15 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
                if (!offset)
                        return -ENOSPC;
                handle->cur->next_swap = offset;
-               error = write_page(handle->cur, handle->cur_swap, bio_chain);
+               error = write_page(handle->cur, handle->cur_swap, hb);
                if (error)
                        goto out;
                clear_page(handle->cur);
                handle->cur_swap = offset;
                handle->k = 0;
 
-               if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
-                       error = hib_wait_on_bio_chain(bio_chain);
+               if (hb && low_free_pages() <= handle->reqd_free_pages) {
+                       error = hib_wait_io(hb);
                        if (error)
                                goto out;
                        /*
@@ -445,23 +522,24 @@ static int save_image(struct swap_map_handle *handle,
        int ret;
        int nr_pages;
        int err2;
-       struct bio *bio;
+       struct hib_bio_batch hb;
        ktime_t start;
        ktime_t stop;
 
+       hib_init_batch(&hb);
+
        printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
                nr_to_write);
        m = nr_to_write / 10;
        if (!m)
                m = 1;
        nr_pages = 0;
-       bio = NULL;
        start = ktime_get();
        while (1) {
                ret = snapshot_read_next(snapshot);
                if (ret <= 0)
                        break;
-               ret = swap_write_page(handle, data_of(*snapshot), &bio);
+               ret = swap_write_page(handle, data_of(*snapshot), &hb);
                if (ret)
                        break;
                if (!(nr_pages % m))
@@ -469,7 +547,7 @@ static int save_image(struct swap_map_handle *handle,
                               nr_pages / m * 10);
                nr_pages++;
        }
-       err2 = hib_wait_on_bio_chain(&bio);
+       err2 = hib_wait_io(&hb);
        stop = ktime_get();
        if (!ret)
                ret = err2;
@@ -580,7 +658,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
        int ret = 0;
        int nr_pages;
        int err2;
-       struct bio *bio;
+       struct hib_bio_batch hb;
        ktime_t start;
        ktime_t stop;
        size_t off;
@@ -589,6 +667,8 @@ static int save_image_lzo(struct swap_map_handle *handle,
        struct cmp_data *data = NULL;
        struct crc_data *crc = NULL;
 
+       hib_init_batch(&hb);
+
        /*
         * We'll limit the number of threads for compression to limit memory
         * footprint.
@@ -674,7 +754,6 @@ static int save_image_lzo(struct swap_map_handle *handle,
        if (!m)
                m = 1;
        nr_pages = 0;
-       bio = NULL;
        start = ktime_get();
        for (;;) {
                for (thr = 0; thr < nr_threads; thr++) {
@@ -748,7 +827,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
                             off += PAGE_SIZE) {
                                memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 
-                               ret = swap_write_page(handle, page, &bio);
+                               ret = swap_write_page(handle, page, &hb);
                                if (ret)
                                        goto out_finish;
                        }
@@ -759,7 +838,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
        }
 
 out_finish:
-       err2 = hib_wait_on_bio_chain(&bio);
+       err2 = hib_wait_io(&hb);
        stop = ktime_get();
        if (!ret)
                ret = err2;
@@ -906,7 +985,7 @@ static int get_swap_reader(struct swap_map_handle *handle,
                        return -ENOMEM;
                }
 
-               error = hib_bio_read_page(offset, tmp->map, NULL);
+               error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
                if (error) {
                        release_swap_reader(handle);
                        return error;
@@ -919,7 +998,7 @@ static int get_swap_reader(struct swap_map_handle *handle,
 }
 
 static int swap_read_page(struct swap_map_handle *handle, void *buf,
-                               struct bio **bio_chain)
+               struct hib_bio_batch *hb)
 {
        sector_t offset;
        int error;
@@ -930,7 +1009,7 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf,
        offset = handle->cur->entries[handle->k];
        if (!offset)
                return -EFAULT;
-       error = hib_bio_read_page(offset, buf, bio_chain);
+       error = hib_submit_io(READ_SYNC, offset, buf, hb);
        if (error)
                return error;
        if (++handle->k >= MAP_PAGE_ENTRIES) {
@@ -968,27 +1047,28 @@ static int load_image(struct swap_map_handle *handle,
        int ret = 0;
        ktime_t start;
        ktime_t stop;
-       struct bio *bio;
+       struct hib_bio_batch hb;
        int err2;
        unsigned nr_pages;
 
+       hib_init_batch(&hb);
+
        printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
                nr_to_read);
        m = nr_to_read / 10;
        if (!m)
                m = 1;
        nr_pages = 0;
-       bio = NULL;
        start = ktime_get();
        for ( ; ; ) {
                ret = snapshot_write_next(snapshot);
                if (ret <= 0)
                        break;
-               ret = swap_read_page(handle, data_of(*snapshot), &bio);
+               ret = swap_read_page(handle, data_of(*snapshot), &hb);
                if (ret)
                        break;
                if (snapshot->sync_read)
-                       ret = hib_wait_on_bio_chain(&bio);
+                       ret = hib_wait_io(&hb);
                if (ret)
                        break;
                if (!(nr_pages % m))
@@ -996,7 +1076,7 @@ static int load_image(struct swap_map_handle *handle,
                               nr_pages / m * 10);
                nr_pages++;
        }
-       err2 = hib_wait_on_bio_chain(&bio);
+       err2 = hib_wait_io(&hb);
        stop = ktime_get();
        if (!ret)
                ret = err2;
@@ -1067,7 +1147,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
        unsigned int m;
        int ret = 0;
        int eof = 0;
-       struct bio *bio;
+       struct hib_bio_batch hb;
        ktime_t start;
        ktime_t stop;
        unsigned nr_pages;
@@ -1080,6 +1160,8 @@ static int load_image_lzo(struct swap_map_handle *handle,
        struct dec_data *data = NULL;
        struct crc_data *crc = NULL;
 
+       hib_init_batch(&hb);
+
        /*
         * We'll limit the number of threads for decompression to limit memory
         * footprint.
@@ -1190,7 +1272,6 @@ static int load_image_lzo(struct swap_map_handle *handle,
        if (!m)
                m = 1;
        nr_pages = 0;
-       bio = NULL;
        start = ktime_get();
 
        ret = snapshot_write_next(snapshot);
@@ -1199,7 +1280,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 
        for(;;) {
                for (i = 0; !eof && i < want; i++) {
-                       ret = swap_read_page(handle, page[ring], &bio);
+                       ret = swap_read_page(handle, page[ring], &hb);
                        if (ret) {
                                /*
                                 * On real read error, finish. On end of data,
@@ -1226,7 +1307,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
                        if (!asked)
                                break;
 
-                       ret = hib_wait_on_bio_chain(&bio);
+                       ret = hib_wait_io(&hb);
                        if (ret)
                                goto out_finish;
                        have += asked;
@@ -1281,7 +1362,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
                 * Wait for more data while we are decompressing.
                 */
                if (have < LZO_CMP_PAGES && asked) {
-                       ret = hib_wait_on_bio_chain(&bio);
+                       ret = hib_wait_io(&hb);
                        if (ret)
                                goto out_finish;
                        have += asked;
@@ -1430,7 +1511,7 @@ int swsusp_check(void)
        if (!IS_ERR(hib_resume_bdev)) {
                set_blocksize(hib_resume_bdev, PAGE_SIZE);
                clear_page(swsusp_header);
-               error = hib_bio_read_page(swsusp_resume_block,
+               error = hib_submit_io(READ_SYNC, swsusp_resume_block,
                                        swsusp_header, NULL);
                if (error)
                        goto put;
@@ -1438,7 +1519,7 @@ int swsusp_check(void)
                if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
                        memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
                        /* Reset swap signature now */
-                       error = hib_bio_write_page(swsusp_resume_block,
+                       error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
                                                swsusp_header, NULL);
                } else {
                        error = -EINVAL;
@@ -1482,10 +1563,10 @@ int swsusp_unmark(void)
 {
        int error;
 
-       hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
+       hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
        if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
                memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
-               error = hib_bio_write_page(swsusp_resume_block,
+               error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
                                        swsusp_header, NULL);
        } else {
                printk(KERN_ERR "PM: Cannot find swsusp signature!\n");

diff --git a/mm/page_io.c b/mm/page_io.c
index 6424869e275e2aa2d09debfa791ea08302ac68be..520baa4b04d75db5acd8711e6a693db634fb8990 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -69,7 +69,7 @@ void end_swap_bio_write(struct bio *bio, int err)
        bio_put(bio);
 }
 
-void end_swap_bio_read(struct bio *bio, int err)
+static void end_swap_bio_read(struct bio *bio, int err)
 {
        const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
        struct page *page = bio->bi_io_vec[0].bv_page;