@@ -878,12 +878,12 @@ static inline unsigned int afs_page_dirty_from(unsigned long priv)
static inline unsigned int afs_page_dirty_to(unsigned long priv)
{
- return (priv >> __AFS_PAGE_PRIV_SHIFT) & __AFS_PAGE_PRIV_MASK;
+ return ((priv >> __AFS_PAGE_PRIV_SHIFT) & __AFS_PAGE_PRIV_MASK) + 1;
}
static inline unsigned long afs_page_dirty(unsigned int from, unsigned int to)
{
- return ((unsigned long)to << __AFS_PAGE_PRIV_SHIFT) | from;
+ return ((unsigned long)(to - 1) << __AFS_PAGE_PRIV_SHIFT) | from;
}
#include <trace/events/afs.h>
Currently, page->private on an afs page is used to store the range of dirtied data within the page, where the range includes the lower bound, but excludes the upper bound (e.g. 0-1 is a range covering a single byte). This, however, requires a superfluous bit for the last-byte bound so that on a 4KiB page, it can say 0-4096 to indicate the whole page, the idea being that having both numbers the same would indicate an empty range. This is unnecessary as the PG_private bit is clear if it's an empty range (as is PG_dirty). Alter the way the dirty range is encoded in page->private such that the upper bound is reduced by 1 (e.g. 0-0 is then specified the same single byte range mentioned above). Applying this to both bounds frees up two bits, one of which can be used in a future commit. Signed-off-by: David Howells <dhowells@redhat.com> --- fs/afs/internal.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)