Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 111 insertions, 0 deletions

diff --git a/mm/fadvise.c b/mm/fadvise.c
new file mode 100644
index 000000000000..57264d74b8bf
--- /dev/null
+++ b/mm/fadvise.c
@@ -0,0 +1,111 @@
+/*
+ * mm/fadvise.c
+ *
+ * Copyright (C) 2002, Linus Torvalds
+ *
+ * 11Jan2003    akpm@digeo.com
+ *              Initial version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/backing-dev.h>
+#include <linux/pagevec.h>
+#include <linux/fadvise.h>
+#include <linux/syscalls.h>
+
+#include <asm/unistd.h>
+
+/*
+ * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
+ * deactivate the pages and clear PG_Referenced.
+ */
+asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
+{
+        struct file *file = fget(fd);
+        struct address_space *mapping;
+        struct backing_dev_info *bdi;
+        loff_t endbyte;
+        pgoff_t start_index;
+        pgoff_t end_index;
+        unsigned long nrpages;
+        int ret = 0;
+
+        if (!file)
+                return -EBADF;
+
+        mapping = file->f_mapping;
+        if (!mapping || len < 0) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        /* Careful about overflows. Len == 0 means "as much as possible" */
+        endbyte = offset + len;
+        if (!len || endbyte < len)
+                endbyte = -1;
+
+        bdi = mapping->backing_dev_info;
+
+        switch (advice) {
+        case POSIX_FADV_NORMAL:
+                file->f_ra.ra_pages = bdi->ra_pages;
+                break;
+        case POSIX_FADV_RANDOM:
+                file->f_ra.ra_pages = 0;
+                break;
+        case POSIX_FADV_SEQUENTIAL:
+                file->f_ra.ra_pages = bdi->ra_pages * 2;
+                break;
+        case POSIX_FADV_WILLNEED:
+        case POSIX_FADV_NOREUSE:
+                if (!mapping->a_ops->readpage) {
+                        ret = -EINVAL;
+                        break;
+                }
+
+                /* First and last PARTIAL page! */
+                start_index = offset >> PAGE_CACHE_SHIFT;
+                end_index = (endbyte-1) >> PAGE_CACHE_SHIFT;
+
+                /* Careful about overflow on the "+1" */
+                nrpages = end_index - start_index + 1;
+                if (!nrpages)
+                        nrpages = ~0UL;
+                
+                ret = force_page_cache_readahead(mapping, file,
+                                start_index,
+                                max_sane_readahead(nrpages));
+                if (ret > 0)
+                        ret = 0;
+                break;
+        case POSIX_FADV_DONTNEED:
+                if (!bdi_write_congested(mapping->backing_dev_info))
+                        filemap_flush(mapping);
+
+                /* First and last FULL page! */
+                start_index = (offset + (PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
+                end_index = (endbyte >> PAGE_CACHE_SHIFT);
+
+                if (end_index > start_index)
+                        invalidate_mapping_pages(mapping, start_index, end_index-1);
+                break;
+        default:
+                ret = -EINVAL;
+        }
+out:
+        fput(file);
+        return ret;
+}
+
+#ifdef __ARCH_WANT_SYS_FADVISE64
+
+asmlinkage long sys_fadvise64(int fd, loff_t offset, size_t len, int advice)
+{
+        return sys_fadvise64_64(fd, offset, len, advice);
+}
+
+#endif