ocfs2: Add inode stealing for ocfs2_reserve_new_inode

Inode allocation is modified to look in other nodes allocators during
extreme out of space situations. We retry our own slot when space is freed
back to the global bitmap, or whenever we've allocated more than 1024 inodes
from another slot.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 32 insertions, 2 deletions

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 9ff5811345a9..31692379c170 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -208,11 +208,14 @@ struct ocfs2_super
         u32 s_feature_incompat;
         u32 s_feature_ro_compat;
 
-        /* Protects s_next_generaion, osb_flags. Could protect more on
-         * osb as it's very short lived. */
+        /* Protects s_next_generation, osb_flags and s_inode_steal_slot.
+         * Could protect more on osb as it's very short lived.
+         */
         spinlock_t osb_lock;
         u32 s_next_generation;
         unsigned long osb_flags;
+        s16 s_inode_steal_slot;
+        atomic_t s_num_inodes_stolen;
 
         unsigned long s_mount_opt;
         unsigned int s_atime_quantum;
@@ -537,6 +540,33 @@ static inline unsigned int ocfs2_pages_per_cluster(struct super_block *sb)
         return pages_per_cluster;
 }
 
+static inline void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
+{
+        spin_lock(&osb->osb_lock);
+        osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
+        spin_unlock(&osb->osb_lock);
+        atomic_set(&osb->s_num_inodes_stolen, 0);
+}
+
+static inline void ocfs2_set_inode_steal_slot(struct ocfs2_super *osb,
+                                              s16 slot)
+{
+        spin_lock(&osb->osb_lock);
+        osb->s_inode_steal_slot = slot;
+        spin_unlock(&osb->osb_lock);
+}
+
+static inline s16 ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
+{
+        s16 slot;
+
+        spin_lock(&osb->osb_lock);
+        slot = osb->s_inode_steal_slot;
+        spin_unlock(&osb->osb_lock);
+
+        return slot;
+}
+
 #define ocfs2_set_bit ext2_set_bit
 #define ocfs2_clear_bit ext2_clear_bit
 #define ocfs2_test_bit ext2_test_bit