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-rw-r--r--mm/Kconfig15
-rw-r--r--mm/backing-dev.c11
-rw-r--r--mm/bounce.c48
-rw-r--r--mm/filemap.c5
-rw-r--r--mm/mmap.c1
-rw-r--r--mm/mremap.c1
-rw-r--r--mm/nommu.c1
-rw-r--r--mm/page-writeback.c25
-rw-r--r--mm/page_alloc.c16
9 files changed, 110 insertions, 13 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index 278e3ab1f169..0b23db9a8791 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1,6 +1,6 @@
config SELECT_MEMORY_MODEL
def_bool y
- depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
+ depends on ARCH_SELECT_MEMORY_MODEL
choice
prompt "Memory model"
@@ -258,6 +258,19 @@ config BOUNCE
def_bool y
depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM)
+# On the 'tile' arch, USB OHCI needs the bounce pool since tilegx will often
+# have more than 4GB of memory, but we don't currently use the IOTLB to present
+# a 32-bit address to OHCI. So we need to use a bounce pool instead.
+#
+# We also use the bounce pool to provide stable page writes for jbd. jbd
+# initiates buffer writeback without locking the page or setting PG_writeback,
+# and fixing that behavior (a second time; jbd2 doesn't have this problem) is
+# a major rework effort. Instead, use the bounce buffer to snapshot pages
+# (until jbd goes away). The only jbd user is ext3.
+config NEED_BOUNCE_POOL
+ bool
+ default y if (TILE && USB_OHCI_HCD) || (BLK_DEV_INTEGRITY && JBD)
+
config NR_QUICK
int
depends on QUICKLIST
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index d3ca2b3ee176..41733c5dc820 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -221,12 +221,23 @@ static ssize_t max_ratio_store(struct device *dev,
}
BDI_SHOW(max_ratio, bdi->max_ratio)
+static ssize_t stable_pages_required_show(struct device *dev,
+ struct device_attribute *attr,
+ char *page)
+{
+ struct backing_dev_info *bdi = dev_get_drvdata(dev);
+
+ return snprintf(page, PAGE_SIZE-1, "%d\n",
+ bdi_cap_stable_pages_required(bdi) ? 1 : 0);
+}
+
#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)
static struct device_attribute bdi_dev_attrs[] = {
__ATTR_RW(read_ahead_kb),
__ATTR_RW(min_ratio),
__ATTR_RW(max_ratio),
+ __ATTR_RO(stable_pages_required),
__ATTR_NULL,
};
diff --git a/mm/bounce.c b/mm/bounce.c
index 042086775561..5f8901768602 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -178,8 +178,45 @@ static void bounce_end_io_read_isa(struct bio *bio, int err)
__bounce_end_io_read(bio, isa_page_pool, err);
}
+#ifdef CONFIG_NEED_BOUNCE_POOL
+static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio)
+{
+ struct page *page;
+ struct backing_dev_info *bdi;
+ struct address_space *mapping;
+ struct bio_vec *from;
+ int i;
+
+ if (bio_data_dir(bio) != WRITE)
+ return 0;
+
+ if (!bdi_cap_stable_pages_required(&q->backing_dev_info))
+ return 0;
+
+ /*
+ * Based on the first page that has a valid mapping, decide whether or
+ * not we have to employ bounce buffering to guarantee stable pages.
+ */
+ bio_for_each_segment(from, bio, i) {
+ page = from->bv_page;
+ mapping = page_mapping(page);
+ if (!mapping)
+ continue;
+ bdi = mapping->backing_dev_info;
+ return mapping->host->i_sb->s_flags & MS_SNAP_STABLE;
+ }
+
+ return 0;
+}
+#else
+static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio)
+{
+ return 0;
+}
+#endif /* CONFIG_NEED_BOUNCE_POOL */
+
static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
- mempool_t *pool)
+ mempool_t *pool, int force)
{
struct page *page;
struct bio *bio = NULL;
@@ -192,7 +229,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
/*
* is destination page below bounce pfn?
*/
- if (page_to_pfn(page) <= queue_bounce_pfn(q))
+ if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force)
continue;
/*
@@ -270,6 +307,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
{
+ int must_bounce;
mempool_t *pool;
/*
@@ -278,13 +316,15 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
if (!bio_has_data(*bio_orig))
return;
+ must_bounce = must_snapshot_stable_pages(q, *bio_orig);
+
/*
* for non-isa bounce case, just check if the bounce pfn is equal
* to or bigger than the highest pfn in the system -- in that case,
* don't waste time iterating over bio segments
*/
if (!(q->bounce_gfp & GFP_DMA)) {
- if (queue_bounce_pfn(q) >= blk_max_pfn)
+ if (queue_bounce_pfn(q) >= blk_max_pfn && !must_bounce)
return;
pool = page_pool;
} else {
@@ -295,7 +335,7 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
/*
* slow path
*/
- __blk_queue_bounce(q, bio_orig, pool);
+ __blk_queue_bounce(q, bio_orig, pool, must_bounce);
}
EXPORT_SYMBOL(blk_queue_bounce);
diff --git a/mm/filemap.c b/mm/filemap.c
index 83efee76a5c0..c610076c30e1 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1728,6 +1728,7 @@ int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
* see the dirty page and writeprotect it again.
*/
set_page_dirty(page);
+ wait_for_stable_page(page);
out:
sb_end_pagefault(inode->i_sb);
return ret;
@@ -2056,7 +2057,7 @@ EXPORT_SYMBOL(iov_iter_fault_in_readable);
/*
* Return the count of just the current iov_iter segment.
*/
-size_t iov_iter_single_seg_count(struct iov_iter *i)
+size_t iov_iter_single_seg_count(const struct iov_iter *i)
{
const struct iovec *iov = i->iov;
if (i->nr_segs == 1)
@@ -2274,7 +2275,7 @@ repeat:
return NULL;
}
found:
- wait_on_page_writeback(page);
+ wait_for_stable_page(page);
return page;
}
EXPORT_SYMBOL(grab_cache_page_write_begin);
diff --git a/mm/mmap.c b/mm/mmap.c
index d1e4124f3d0e..09da0b264982 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -32,6 +32,7 @@
#include <linux/khugepaged.h>
#include <linux/uprobes.h>
#include <linux/rbtree_augmented.h>
+#include <linux/sched/sysctl.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
diff --git a/mm/mremap.c b/mm/mremap.c
index e1031e1f6a61..f9766f460299 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -19,6 +19,7 @@
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/mmu_notifier.h>
+#include <linux/sched/sysctl.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
diff --git a/mm/nommu.c b/mm/nommu.c
index 79c3cac87afa..b20db4e22263 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -29,6 +29,7 @@
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/audit.h>
+#include <linux/sched/sysctl.h>
#include <asm/uaccess.h>
#include <asm/tlb.h>
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0713bfbf0954..7300c9d5e1d9 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -35,6 +35,7 @@
#include <linux/buffer_head.h> /* __set_page_dirty_buffers */
#include <linux/pagevec.h>
#include <linux/timer.h>
+#include <linux/sched/rt.h>
#include <trace/events/writeback.h>
/*
@@ -2289,3 +2290,27 @@ int mapping_tagged(struct address_space *mapping, int tag)
return radix_tree_tagged(&mapping->page_tree, tag);
}
EXPORT_SYMBOL(mapping_tagged);
+
+/**
+ * wait_for_stable_page() - wait for writeback to finish, if necessary.
+ * @page: The page to wait on.
+ *
+ * This function determines if the given page is related to a backing device
+ * that requires page contents to be held stable during writeback. If so, then
+ * it will wait for any pending writeback to complete.
+ */
+void wait_for_stable_page(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+
+ if (!bdi_cap_stable_pages_required(bdi))
+ return;
+#ifdef CONFIG_NEED_BOUNCE_POOL
+ if (mapping->host->i_sb->s_flags & MS_SNAP_STABLE)
+ return;
+#endif /* CONFIG_NEED_BOUNCE_POOL */
+
+ wait_on_page_writeback(page);
+}
+EXPORT_SYMBOL_GPL(wait_for_stable_page);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9673d96b1ba7..d1107adf174a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -58,6 +58,7 @@
#include <linux/prefetch.h>
#include <linux/migrate.h>
#include <linux/page-debug-flags.h>
+#include <linux/sched/rt.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -4420,10 +4421,11 @@ static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
* round what is now in bits to nearest long in bits, then return it in
* bytes.
*/
-static unsigned long __init usemap_size(unsigned long zonesize)
+static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
{
unsigned long usemapsize;
+ zonesize += zone_start_pfn & (pageblock_nr_pages-1);
usemapsize = roundup(zonesize, pageblock_nr_pages);
usemapsize = usemapsize >> pageblock_order;
usemapsize *= NR_PAGEBLOCK_BITS;
@@ -4433,17 +4435,19 @@ static unsigned long __init usemap_size(unsigned long zonesize)
}
static void __init setup_usemap(struct pglist_data *pgdat,
- struct zone *zone, unsigned long zonesize)
+ struct zone *zone,
+ unsigned long zone_start_pfn,
+ unsigned long zonesize)
{
- unsigned long usemapsize = usemap_size(zonesize);
+ unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
zone->pageblock_flags = NULL;
if (usemapsize)
zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
usemapsize);
}
#else
-static inline void setup_usemap(struct pglist_data *pgdat,
- struct zone *zone, unsigned long zonesize) {}
+static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
+ unsigned long zone_start_pfn, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
@@ -4594,7 +4598,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
continue;
set_pageblock_order();
- setup_usemap(pgdat, zone, size);
+ setup_usemap(pgdat, zone, zone_start_pfn, size);
ret = init_currently_empty_zone(zone, zone_start_pfn,
size, MEMMAP_EARLY);
BUG_ON(ret);