1 files changed, 104 insertions, 0 deletions
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
new file mode 100644
index 000000000..fdd9d6ede
--- /dev/null
+++ b/fs/xfs/kmem.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include <linux/mm.h>
+#include <linux/sched/mm.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include "kmem.h"
+#include "xfs_message.h"
+
+void *
+kmem_alloc(size_t size, xfs_km_flags_t flags)
+{
+	int	retries = 0;
+	gfp_t	lflags = kmem_flags_convert(flags);
+	void	*ptr;
+
+	do {
+		ptr = kmalloc(size, lflags);
+		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
+			return ptr;
+		if (!(++retries % 100))
+			xfs_err(NULL,
+	"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
+				current->comm, current->pid,
+				(unsigned int)size, __func__, lflags);
+		congestion_wait(BLK_RW_ASYNC, HZ/50);
+	} while (1);
+}
+
+void *
+kmem_alloc_large(size_t size, xfs_km_flags_t flags)
+{
+	unsigned nofs_flag = 0;
+	void	*ptr;
+	gfp_t	lflags;
+
+	ptr = kmem_alloc(size, flags | KM_MAYFAIL);
+	if (ptr)
+		return ptr;
+
+	/*
+	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
+	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
+	 * here. Hence we need to tell memory reclaim that we are in such a
+	 * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
+	 * the filesystem here and potentially deadlocking.
+	 */
+	if (flags & KM_NOFS)
+		nofs_flag = memalloc_nofs_save();
+
+	lflags = kmem_flags_convert(flags);
+	ptr = __vmalloc(size, lflags, PAGE_KERNEL);
+
+	if (flags & KM_NOFS)
+		memalloc_nofs_restore(nofs_flag);
+
+	return ptr;
+}
+
+void *
+kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
+{
+	int	retries = 0;
+	gfp_t	lflags = kmem_flags_convert(flags);
+	void	*ptr;
+
+	do {
+		ptr = krealloc(old, newsize, lflags);
+		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
+			return ptr;
+		if (!(++retries % 100))
+			xfs_err(NULL,
+	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
+				current->comm, current->pid,
+				newsize, __func__, lflags);
+		congestion_wait(BLK_RW_ASYNC, HZ/50);
+	} while (1);
+}
+
+void *
+kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
+{
+	int	retries = 0;
+	gfp_t	lflags = kmem_flags_convert(flags);
+	void	*ptr;
+
+	do {
+		ptr = kmem_cache_alloc(zone, lflags);
+		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
+			return ptr;
+		if (!(++retries % 100))
+			xfs_err(NULL,
+		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
+				current->comm, current->pid,
+				__func__, lflags);
+		congestion_wait(BLK_RW_ASYNC, HZ/50);
+	} while (1);
+}