X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=mm%2Fz3fold.c;h=1a029a7432ee56635f9dcde8f4c5ad2b1e2984ed;hb=81a43273045b116901e569ca27ddf55550f92caf;hp=985732c8b025eb0c4064a18243114b25b34e5e87;hpb=5b7a2095232d026d4537c4be54040c0f10525b5b;p=linux.git

diff --git a/mm/z3fold.c b/mm/z3fold.c
index 985732c8b025..1a029a7432ee 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -26,7 +26,6 @@
 #include <linux/atomic.h>
 #include <linux/sched.h>
 #include <linux/cpumask.h>
-#include <linux/dcache.h>
 #include <linux/list.h>
 #include <linux/mm.h>
 #include <linux/module.h>
@@ -36,12 +35,14 @@
 #include <linux/compaction.h>
 #include <linux/percpu.h>
 #include <linux/mount.h>
+#include <linux/pseudo_fs.h>
 #include <linux/fs.h>
 #include <linux/preempt.h>
 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/zpool.h>
+#include <linux/magic.h>
 
 /*
  * NCHUNKS_ORDER determines the internal allocation granularity, effectively
@@ -101,6 +102,7 @@ struct z3fold_buddy_slots {
  * @refcount:		reference count for the z3fold page
  * @work:		work_struct for page layout optimization
  * @slots:		pointer to the structure holding buddy slots
+ * @pool:		pointer to the containing pool
  * @cpu:		CPU which this page "belongs" to
  * @first_chunks:	the size of the first buddy in chunks, 0 if free
  * @middle_chunks:	the size of the middle buddy in chunks, 0 if free
@@ -114,6 +116,7 @@ struct z3fold_header {
 	struct kref refcount;
 	struct work_struct work;
 	struct z3fold_buddy_slots *slots;
+	struct z3fold_pool *pool;
 	short cpu;
 	unsigned short first_chunks;
 	unsigned short middle_chunks;
@@ -193,8 +196,10 @@ static void compact_page_work(struct work_struct *w);
 static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
 							gfp_t gfp)
 {
-	struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle,
-							    gfp);
+	struct z3fold_buddy_slots *slots;
+
+	slots = kmem_cache_alloc(pool->c_handle,
+				 (gfp & ~(__GFP_HIGHMEM | __GFP_MOVABLE)));
 
 	if (slots) {
 		memset(slots->slot, 0, sizeof(slots->slot));
@@ -241,19 +246,14 @@ static inline void free_handle(unsigned long handle)
 	}
 }
 
-static struct dentry *z3fold_do_mount(struct file_system_type *fs_type,
-				int flags, const char *dev_name, void *data)
+static int z3fold_init_fs_context(struct fs_context *fc)
 {
-	static const struct dentry_operations ops = {
-		.d_dname = simple_dname,
-	};
-
-	return mount_pseudo(fs_type, "z3fold:", NULL, &ops, 0x33);
+	return init_pseudo(fc, Z3FOLD_MAGIC) ? 0 : -ENOMEM;
 }
 
 static struct file_system_type z3fold_fs = {
 	.name		= "z3fold",
-	.mount		= z3fold_do_mount,
+	.init_fs_context = z3fold_init_fs_context,
 	.kill_sb	= kill_anon_super,
 };
 
@@ -320,6 +320,7 @@ static struct z3fold_header *init_z3fold_page(struct page *page,
 	zhdr->start_middle = 0;
 	zhdr->cpu = -1;
 	zhdr->slots = slots;
+	zhdr->pool = pool;
 	INIT_LIST_HEAD(&zhdr->buddy);
 	INIT_WORK(&zhdr->work, compact_page_work);
 	return zhdr;
@@ -426,7 +427,7 @@ static enum buddy handle_to_buddy(unsigned long handle)
 
 static inline struct z3fold_pool *zhdr_to_pool(struct z3fold_header *zhdr)
 {
-	return slots_to_pool(zhdr->slots);
+	return zhdr->pool;
 }
 
 static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked)
@@ -850,7 +851,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
 	enum buddy bud;
 	bool can_sleep = gfpflags_allow_blocking(gfp);
 
-	if (!size || (gfp & __GFP_HIGHMEM))
+	if (!size)
 		return -EINVAL;
 
 	if (size > PAGE_SIZE)
@@ -924,7 +925,16 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
 		set_bit(PAGE_HEADLESS, &page->private);
 		goto headless;
 	}
-	__SetPageMovable(page, pool->inode->i_mapping);
+	if (can_sleep) {
+		lock_page(page);
+		__SetPageMovable(page, pool->inode->i_mapping);
+		unlock_page(page);
+	} else {
+		if (trylock_page(page)) {
+			__SetPageMovable(page, pool->inode->i_mapping);
+			unlock_page(page);
+		}
+	}
 	z3fold_page_lock(zhdr);
 
 found:
@@ -1331,28 +1341,34 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
 
 	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	VM_BUG_ON_PAGE(!PageIsolated(page), page);
+	VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
 
 	zhdr = page_address(page);
 	pool = zhdr_to_pool(zhdr);
 
-	if (!trylock_page(page))
-		return -EAGAIN;
-
 	if (!z3fold_page_trylock(zhdr)) {
-		unlock_page(page);
 		return -EAGAIN;
 	}
 	if (zhdr->mapped_count != 0) {
 		z3fold_page_unlock(zhdr);
-		unlock_page(page);
 		return -EBUSY;
 	}
+	if (work_pending(&zhdr->work)) {
+		z3fold_page_unlock(zhdr);
+		return -EAGAIN;
+	}
 	new_zhdr = page_address(newpage);
 	memcpy(new_zhdr, zhdr, PAGE_SIZE);
 	newpage->private = page->private;
 	page->private = 0;
 	z3fold_page_unlock(zhdr);
 	spin_lock_init(&new_zhdr->page_lock);
+	INIT_WORK(&new_zhdr->work, compact_page_work);
+	/*
+	 * z3fold_page_isolate() ensures that new_zhdr->buddy is empty,
+	 * so we only have to reinitialize it.
+	 */
+	INIT_LIST_HEAD(&new_zhdr->buddy);
 	new_mapping = page_mapping(page);
 	__ClearPageMovable(page);
 	ClearPagePrivate(page);
@@ -1376,7 +1392,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
 	queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work);
 
 	page_mapcount_reset(page);
-	unlock_page(page);
 	put_page(page);
 	return 0;
 }