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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/xfs/kmem.c
Initial import
Diffstat (limited to 'fs/xfs/kmem.c')
-rw-r--r--fs/xfs/kmem.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
new file mode 100644
index 000000000..a7a3a63bb
--- /dev/null
+++ b/fs/xfs/kmem.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/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"
+
+/*
+ * Greedy allocation. May fail and may return vmalloced memory.
+ */
+void *
+kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
+{
+ void *ptr;
+ size_t kmsize = maxsize;
+
+ while (!(ptr = vzalloc(kmsize))) {
+ if ((kmsize >>= 1) <= minsize)
+ kmsize = minsize;
+ }
+ if (ptr)
+ *size = kmsize;
+ return ptr;
+}
+
+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,
+ "possible memory allocation deadlock in %s (mode:0x%x)",
+ __func__, lflags);
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
+ } while (1);
+}
+
+void *
+kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
+{
+ unsigned noio_flag = 0;
+ void *ptr;
+ gfp_t lflags;
+
+ ptr = kmem_zalloc(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_NOIO to prevent memory reclaim re-entering
+ * the filesystem here and potentially deadlocking.
+ */
+ if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
+ noio_flag = memalloc_noio_save();
+
+ lflags = kmem_flags_convert(flags);
+ ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
+
+ if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
+ memalloc_noio_restore(noio_flag);
+
+ return ptr;
+}
+
+void *
+kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
+ xfs_km_flags_t flags)
+{
+ void *new;
+
+ new = kmem_alloc(newsize, flags);
+ if (ptr) {
+ if (new)
+ memcpy(new, ptr,
+ ((oldsize < newsize) ? oldsize : newsize));
+ kmem_free(ptr);
+ }
+ return new;
+}
+
+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,
+ "possible memory allocation deadlock in %s (mode:0x%x)",
+ __func__, lflags);
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
+ } while (1);
+}