Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / xfs / kmem.c

diff --git a/kernel/fs/xfs/kmem.c b/kernel/fs/xfs/kmem.c
new file mode 100644 (file)
index 0000000..a7a3a63
--- /dev/null
+++ b/kernel/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);
+}