page cache: use xa_lock
Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root. Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.
[willy@infradead.org: fix nds32, fs/dax.c]
Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index 4424fc0..9d6c7e5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -332,12 +332,12 @@ static int shmem_radix_tree_replace(struct address_space *mapping,
VM_BUG_ON(!expected);
VM_BUG_ON(!replacement);
- item = __radix_tree_lookup(&mapping->page_tree, index, &node, &pslot);
+ item = __radix_tree_lookup(&mapping->i_pages, index, &node, &pslot);
if (!item)
return -ENOENT;
if (item != expected)
return -ENOENT;
- __radix_tree_replace(&mapping->page_tree, node, pslot,
+ __radix_tree_replace(&mapping->i_pages, node, pslot,
replacement, NULL);
return 0;
}
@@ -355,7 +355,7 @@ static bool shmem_confirm_swap(struct address_space *mapping,
void *item;
rcu_read_lock();
- item = radix_tree_lookup(&mapping->page_tree, index);
+ item = radix_tree_lookup(&mapping->i_pages, index);
rcu_read_unlock();
return item == swp_to_radix_entry(swap);
}
@@ -590,14 +590,14 @@ static int shmem_add_to_page_cache(struct page *page,
page->mapping = mapping;
page->index = index;
- spin_lock_irq(&mapping->tree_lock);
+ xa_lock_irq(&mapping->i_pages);
if (PageTransHuge(page)) {
void __rcu **results;
pgoff_t idx;
int i;
error = 0;
- if (radix_tree_gang_lookup_slot(&mapping->page_tree,
+ if (radix_tree_gang_lookup_slot(&mapping->i_pages,
&results, &idx, index, 1) &&
idx < index + HPAGE_PMD_NR) {
error = -EEXIST;
@@ -605,14 +605,14 @@ static int shmem_add_to_page_cache(struct page *page,
if (!error) {
for (i = 0; i < HPAGE_PMD_NR; i++) {
- error = radix_tree_insert(&mapping->page_tree,
+ error = radix_tree_insert(&mapping->i_pages,
index + i, page + i);
VM_BUG_ON(error);
}
count_vm_event(THP_FILE_ALLOC);
}
} else if (!expected) {
- error = radix_tree_insert(&mapping->page_tree, index, page);
+ error = radix_tree_insert(&mapping->i_pages, index, page);
} else {
error = shmem_radix_tree_replace(mapping, index, expected,
page);
@@ -624,10 +624,10 @@ static int shmem_add_to_page_cache(struct page *page,
__inc_node_page_state(page, NR_SHMEM_THPS);
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
__mod_node_page_state(page_pgdat(page), NR_SHMEM, nr);
- spin_unlock_irq(&mapping->tree_lock);
+ xa_unlock_irq(&mapping->i_pages);
} else {
page->mapping = NULL;
- spin_unlock_irq(&mapping->tree_lock);
+ xa_unlock_irq(&mapping->i_pages);
page_ref_sub(page, nr);
}
return error;
@@ -643,13 +643,13 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
VM_BUG_ON_PAGE(PageCompound(page), page);
- spin_lock_irq(&mapping->tree_lock);
+ xa_lock_irq(&mapping->i_pages);
error = shmem_radix_tree_replace(mapping, page->index, page, radswap);
page->mapping = NULL;
mapping->nrpages--;
__dec_node_page_state(page, NR_FILE_PAGES);
__dec_node_page_state(page, NR_SHMEM);
- spin_unlock_irq(&mapping->tree_lock);
+ xa_unlock_irq(&mapping->i_pages);
put_page(page);
BUG_ON(error);
}
@@ -662,9 +662,9 @@ static int shmem_free_swap(struct address_space *mapping,
{
void *old;
- spin_lock_irq(&mapping->tree_lock);
- old = radix_tree_delete_item(&mapping->page_tree, index, radswap);
- spin_unlock_irq(&mapping->tree_lock);
+ xa_lock_irq(&mapping->i_pages);
+ old = radix_tree_delete_item(&mapping->i_pages, index, radswap);
+ xa_unlock_irq(&mapping->i_pages);
if (old != radswap)
return -ENOENT;
free_swap_and_cache(radix_to_swp_entry(radswap));
@@ -675,7 +675,7 @@ static int shmem_free_swap(struct address_space *mapping,
* Determine (in bytes) how many of the shmem object's pages mapped by the
* given offsets are swapped out.
*
- * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU,
+ * This is safe to call without i_mutex or the i_pages lock thanks to RCU,
* as long as the inode doesn't go away and racy results are not a problem.
*/
unsigned long shmem_partial_swap_usage(struct address_space *mapping,
@@ -688,7 +688,7 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
+ radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
if (iter.index >= end)
break;
@@ -717,7 +717,7 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
* Determine (in bytes) how many of the shmem object's pages mapped by the
* given vma is swapped out.
*
- * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU,
+ * This is safe to call without i_mutex or the i_pages lock thanks to RCU,
* as long as the inode doesn't go away and racy results are not a problem.
*/
unsigned long shmem_swap_usage(struct vm_area_struct *vma)
@@ -1132,7 +1132,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
int error = 0;
radswap = swp_to_radix_entry(swap);
- index = find_swap_entry(&mapping->page_tree, radswap);
+ index = find_swap_entry(&mapping->i_pages, radswap);
if (index == -1)
return -EAGAIN; /* tell shmem_unuse we found nothing */
@@ -1448,7 +1448,7 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp,
hindex = round_down(index, HPAGE_PMD_NR);
rcu_read_lock();
- if (radix_tree_gang_lookup_slot(&mapping->page_tree, &results, &idx,
+ if (radix_tree_gang_lookup_slot(&mapping->i_pages, &results, &idx,
hindex, 1) && idx < hindex + HPAGE_PMD_NR) {
rcu_read_unlock();
return NULL;
@@ -1561,14 +1561,14 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
* Our caller will very soon move newpage out of swapcache, but it's
* a nice clean interface for us to replace oldpage by newpage there.
*/
- spin_lock_irq(&swap_mapping->tree_lock);
+ xa_lock_irq(&swap_mapping->i_pages);
error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage,
newpage);
if (!error) {
__inc_node_page_state(newpage, NR_FILE_PAGES);
__dec_node_page_state(oldpage, NR_FILE_PAGES);
}
- spin_unlock_irq(&swap_mapping->tree_lock);
+ xa_unlock_irq(&swap_mapping->i_pages);
if (unlikely(error)) {
/*
@@ -2634,7 +2634,7 @@ static void shmem_tag_pins(struct address_space *mapping)
start = 0;
rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
+ radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
page = radix_tree_deref_slot(slot);
if (!page || radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
@@ -2642,10 +2642,10 @@ static void shmem_tag_pins(struct address_space *mapping)
continue;
}
} else if (page_count(page) - page_mapcount(page) > 1) {
- spin_lock_irq(&mapping->tree_lock);
- radix_tree_tag_set(&mapping->page_tree, iter.index,
+ xa_lock_irq(&mapping->i_pages);
+ radix_tree_tag_set(&mapping->i_pages, iter.index,
SHMEM_TAG_PINNED);
- spin_unlock_irq(&mapping->tree_lock);
+ xa_unlock_irq(&mapping->i_pages);
}
if (need_resched()) {
@@ -2677,7 +2677,7 @@ static int shmem_wait_for_pins(struct address_space *mapping)
error = 0;
for (scan = 0; scan <= LAST_SCAN; scan++) {
- if (!radix_tree_tagged(&mapping->page_tree, SHMEM_TAG_PINNED))
+ if (!radix_tree_tagged(&mapping->i_pages, SHMEM_TAG_PINNED))
break;
if (!scan)
@@ -2687,7 +2687,7 @@ static int shmem_wait_for_pins(struct address_space *mapping)
start = 0;
rcu_read_lock();
- radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter,
+ radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter,
start, SHMEM_TAG_PINNED) {
page = radix_tree_deref_slot(slot);
@@ -2713,10 +2713,10 @@ static int shmem_wait_for_pins(struct address_space *mapping)
error = -EBUSY;
}
- spin_lock_irq(&mapping->tree_lock);
- radix_tree_tag_clear(&mapping->page_tree,
+ xa_lock_irq(&mapping->i_pages);
+ radix_tree_tag_clear(&mapping->i_pages,
iter.index, SHMEM_TAG_PINNED);
- spin_unlock_irq(&mapping->tree_lock);
+ xa_unlock_irq(&mapping->i_pages);
continue_resched:
if (need_resched()) {
slot = radix_tree_iter_resume(slot, &iter);
