6 files changed, 116 insertions, 5 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 7d81aa6f5672..a26882144e8f 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -5150,6 +5150,8 @@ static void ocfs2_truncate_log_worker(struct work_struct *work)
         status = ocfs2_flush_truncate_log(osb);
         if (status < 0)
                 mlog_errno(status);
+        else
+                ocfs2_init_inode_steal_slot(osb);
 
         mlog_exit(status);
 }
diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index b6d07198118c..ce0dc147602a 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -447,6 +447,8 @@ out_mutex:
         iput(main_bm_inode);
 
 out:
+        if (!status)
+                ocfs2_init_inode_steal_slot(osb);
         mlog_exit(status);
         return status;
 }
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index ae9ad9587516..ab5a2272d0eb 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -424,7 +424,7 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
         fe->i_fs_generation = cpu_to_le32(osb->fs_generation);
         fe->i_blkno = cpu_to_le64(fe_blkno);
         fe->i_suballoc_bit = cpu_to_le16(suballoc_bit);
-        fe->i_suballoc_slot = cpu_to_le16(osb->slot_num);
+        fe->i_suballoc_slot = cpu_to_le16(inode_ac->ac_alloc_slot);
         fe->i_uid = cpu_to_le32(current->fsuid);
         if (dir->i_mode & S_ISGID) {
                 fe->i_gid = cpu_to_le32(dir->i_gid);
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
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 33d55734c514..d2d278fb9819 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -49,6 +49,8 @@
 #define NOT_ALLOC_NEW_GROUP             0
 #define ALLOC_NEW_GROUP                 1
 
+#define OCFS2_MAX_INODES_TO_STEAL       1024
+
 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
@@ -109,7 +111,7 @@ static inline void ocfs2_block_to_cluster_group(struct inode *inode,
                                                 u64 *bg_blkno,
                                                 u16 *bg_bit_off);
 
-void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
+static void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 {
         struct inode *inode = ac->ac_inode;
 
@@ -120,9 +122,17 @@ void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
                 mutex_unlock(&inode->i_mutex);
 
                 iput(inode);
+                ac->ac_inode = NULL;
         }
-        if (ac->ac_bh)
+        if (ac->ac_bh) {
                 brelse(ac->ac_bh);
+                ac->ac_bh = NULL;
+        }
+}
+
+void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
+{
+        ocfs2_free_ac_resource(ac);
         kfree(ac);
 }
 
@@ -522,10 +532,42 @@ bail:
         return status;
 }
 
+static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
+                                              struct ocfs2_alloc_context *ac)
+{
+        int i, status = -ENOSPC;
+        s16 slot = ocfs2_get_inode_steal_slot(osb);
+
+        /* Start to steal inodes from the first slot after ours. */
+        if (slot == OCFS2_INVALID_SLOT)
+                slot = osb->slot_num + 1;
+
+        for (i = 0; i < osb->max_slots; i++, slot++) {
+                if (slot == osb->max_slots)
+                        slot = 0;
+
+                if (slot == osb->slot_num)
+                        continue;
+
+                status = ocfs2_reserve_suballoc_bits(osb, ac,
+                                                     INODE_ALLOC_SYSTEM_INODE,
+                                                     slot, NOT_ALLOC_NEW_GROUP);
+                if (status >= 0) {
+                        ocfs2_set_inode_steal_slot(osb, slot);
+                        break;
+                }
+
+                ocfs2_free_ac_resource(ac);
+        }
+
+        return status;
+}
+
 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
                             struct ocfs2_alloc_context **ac)
 {
         int status;
+        s16 slot = ocfs2_get_inode_steal_slot(osb);
 
         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
         if (!(*ac)) {
@@ -539,9 +581,43 @@ int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 
         (*ac)->ac_group_search = ocfs2_block_group_search;
 
+        /*
+         * slot is set when we successfully steal inode from other nodes.
+         * It is reset in 3 places:
+         * 1. when we flush the truncate log
+         * 2. when we complete local alloc recovery.
+         * 3. when we successfully allocate from our own slot.
+         * After it is set, we will go on stealing inodes until we find the
+         * need to check our slots to see whether there is some space for us.
+         */
+        if (slot != OCFS2_INVALID_SLOT &&
+            atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
+                goto inode_steal;
+
+        atomic_set(&osb->s_num_inodes_stolen, 0);
         status = ocfs2_reserve_suballoc_bits(osb, *ac,
                                              INODE_ALLOC_SYSTEM_INODE,
                                              osb->slot_num, ALLOC_NEW_GROUP);
+        if (status >= 0) {
+                status = 0;
+
+                /*
+                 * Some inodes must be freed by us, so try to allocate
+                 * from our own next time.
+                 */
+                if (slot != OCFS2_INVALID_SLOT)
+                        ocfs2_init_inode_steal_slot(osb);
+                goto bail;
+        } else if (status < 0 && status != -ENOSPC) {
+                mlog_errno(status);
+                goto bail;
+        }
+
+        ocfs2_free_ac_resource(*ac);
+
+inode_steal:
+        status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
+        atomic_inc(&osb->s_num_inodes_stolen);
         if (status < 0) {
                 if (status != -ENOSPC)
                         mlog_errno(status);
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 96ebe36d5d77..df63ba20ae90 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1394,6 +1394,7 @@ static int ocfs2_initialize_super(struct super_block *sb,
         INIT_LIST_HEAD(&osb->blocked_lock_list);
         osb->blocked_lock_count = 0;
         spin_lock_init(&osb->osb_lock);
+        ocfs2_init_inode_steal_slot(osb);
 
         atomic_set(&osb->alloc_stats.moves, 0);
         atomic_set(&osb->alloc_stats.local_data, 0);