diff --git a/include/linux/fadvise.h b/include/linux/fadvise.h
index e8e747139b9a1483897f8c4b0aa9e8b9f4a49588..b2913bba35d87dafbb042b086face216609cb107 100644
--- a/include/linux/fadvise.h
+++ b/include/linux/fadvise.h
@@ -18,4 +18,10 @@
#define POSIX_FADV_NOREUSE 5 /* Data will be accessed once. */
#endif
+/*
+ * Linux-specific fadvise() extensions:
+ */
+#define LINUX_FADV_ASYNC_WRITE 32 /* Start writeout on range */
+#define LINUX_FADV_WRITE_WAIT 33 /* Wait upon writeout to range */
+
#endif /* FADVISE_H_INCLUDED */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 65e6df247ea559c3c40e22c8593926a8962ccb45..0ad70c1e5e5573cc27e9dbd86bed77eca7aeecc9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1473,6 +1473,11 @@ extern int filemap_fdatawait(struct address_space *);
extern int filemap_write_and_wait(struct address_space *mapping);
extern int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend);
+extern int wait_on_page_writeback_range(struct address_space *mapping,
+ pgoff_t start, pgoff_t end);
+extern int __filemap_fdatawrite_range(struct address_space *mapping,
+ loff_t start, loff_t end, int sync_mode);
+
extern void sync_supers(void);
extern void sync_filesystems(int wait);
extern void emergency_sync(void);
diff --git a/mm/fadvise.c b/mm/fadvise.c
index d257c89e7704c60d8decf405c89c46f8de262153..907c39257ca06aea630915c9a46103518a4d631a 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -15,6 +15,7 @@
#include <linux/backing-dev.h>
#include <linux/pagevec.h>
#include <linux/fadvise.h>
+#include <linux/writeback.h>
#include <linux/syscalls.h>
#include <asm/unistd.h>
@@ -22,13 +23,36 @@
/*
* POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
* deactivate the pages and clear PG_Referenced.
+ *
+ * LINUX_FADV_ASYNC_WRITE: start async writeout of any dirty pages between file
+ * offsets `offset' and `offset+len' inclusive. Any pages which are currently
+ * under writeout are skipped, whether or not they are dirty.
+ *
+ * LINUX_FADV_WRITE_WAIT: wait upon writeout of any dirty pages between file
+ * offsets `offset' and `offset+len'.
+ *
+ * By combining these two operations the application may do several things:
+ *
+ * LINUX_FADV_ASYNC_WRITE: push some or all of the dirty pages at the disk.
+ *
+ * LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE: push all of the currently
+ * dirty pages at the disk.
+ *
+ * LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE, LINUX_FADV_WRITE_WAIT: push
+ * all of the currently dirty pages at the disk, wait until they have been
+ * written.
+ *
+ * It should be noted that none of these operations write out the file's
+ * metadata. So unless the application is strictly performing overwrites of
+ * already-instantiated disk blocks, there are no guarantees here that the data
+ * will be available after a crash.
*/
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;
+ loff_t endbyte; /* inclusive */
pgoff_t start_index;
pgoff_t end_index;
unsigned long nrpages;
@@ -56,6 +80,8 @@ asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
endbyte = offset + len;
if (!len || endbyte < len)
endbyte = -1;
+ else
+ endbyte--; /* inclusive */
bdi = mapping->backing_dev_info;
@@ -78,7 +104,7 @@ asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
/* First and last PARTIAL page! */
start_index = offset >> PAGE_CACHE_SHIFT;
- end_index = (endbyte-1) >> PAGE_CACHE_SHIFT;
+ end_index = endbyte >> PAGE_CACHE_SHIFT;
/* Careful about overflow on the "+1" */
nrpages = end_index - start_index + 1;
@@ -96,11 +122,21 @@ asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
filemap_flush(mapping);
/* First and last FULL page! */
- start_index = (offset + (PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
+ 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);
+ if (end_index >= start_index)
+ invalidate_mapping_pages(mapping, start_index,
+ end_index);
+ break;
+ case LINUX_FADV_ASYNC_WRITE:
+ ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
+ WB_SYNC_NONE);
+ break;
+ case LINUX_FADV_WRITE_WAIT:
+ ret = wait_on_page_writeback_range(mapping,
+ offset >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
break;
default:
ret = -EINVAL;
diff --git a/mm/filemap.c b/mm/filemap.c
index c1b1708cc95de637a7fc18f88ac2f04f6a8353aa..3ef20739e7252232c5822cbeed6e22eaa5247d0c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -183,8 +183,8 @@ static int sync_page(void *word)
* these two operations is that if a dirty page/buffer is encountered, it must
* be waited upon, and not just skipped over.
*/
-static int __filemap_fdatawrite_range(struct address_space *mapping,
- loff_t start, loff_t end, int sync_mode)
+int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end, int sync_mode)
{
int ret;
struct writeback_control wbc = {
@@ -213,8 +213,8 @@ int filemap_fdatawrite(struct address_space *mapping)
}
EXPORT_SYMBOL(filemap_fdatawrite);
-static int filemap_fdatawrite_range(struct address_space *mapping,
- loff_t start, loff_t end)
+static int filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end)
{
return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_ALL);
}
@@ -233,7 +233,7 @@ EXPORT_SYMBOL(filemap_flush);
* Wait for writeback to complete against pages indexed by start->end
* inclusive
*/
-static int wait_on_page_writeback_range(struct address_space *mapping,
+int wait_on_page_writeback_range(struct address_space *mapping,
pgoff_t start, pgoff_t end)
{
struct pagevec pvec;