ocfs2: use allocation reservations for directory data

Use the reservations system for unindexed dir tree allocations. We don't
bother with the indexed tree as reads from it are mostly random anyway.
Directory reservations are marked seperately, to allow the reservations code
a chance to optimize their window sizes. This patch allocates only 8 bits
for directory windows as they generally are not expected to grow as quickly
as file data. Future improvements to dir window sizing can trivially be
made.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/ocfs2/reservations.c b/fs/ocfs2/reservations.c
index 79642d608210..7fc6cfee95f1 100644
--- a/fs/ocfs2/reservations.c
+++ b/fs/ocfs2/reservations.c
@@ -44,6 +44,7 @@ DEFINE_SPINLOCK(resv_lock);
 
 #define OCFS2_MIN_RESV_WINDOW_BITS      8
 #define OCFS2_MAX_RESV_WINDOW_BITS      1024
+#define OCFS2_RESV_DIR_WINDOW_BITS      OCFS2_MIN_RESV_WINDOW_BITS
 
 static unsigned int ocfs2_resv_window_bits(struct ocfs2_reservation_map *resmap,
                                            struct ocfs2_alloc_reservation *resv)
@@ -51,8 +52,11 @@ static unsigned int ocfs2_resv_window_bits(struct ocfs2_reservation_map *resmap,
         struct ocfs2_super *osb = resmap->m_osb;
         unsigned int bits;
 
-        /* 8, 16, 32, 64, 128, 256, 512, 1024 */
-        bits = 4 << osb->osb_resv_level;
+        if (!(resv->r_flags & OCFS2_RESV_FLAG_DIR)) {
+                /* 8, 16, 32, 64, 128, 256, 512, 1024 */
+                bits = 4 << osb->osb_resv_level;
+        } else
+                bits = OCFS2_RESV_DIR_WINDOW_BITS;
 
         return bits;
 }