4 files changed, 145 insertions, 13 deletions

diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index 0d1973ea32b0..1f17a4d08287 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -840,6 +840,12 @@ static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
 
         mlog(0, "Allocating %u clusters for a new window.\n",
              ocfs2_local_alloc_window_bits(osb));
+
+        /* Instruct the allocation code to try the most recently used
+         * cluster group. We'll re-record the group used this pass
+         * below. */
+        ac->ac_last_group = osb->la_last_gd;
+
         /* we used the generic suballoc reserve function, but we set
          * everything up nicely, so there's no reason why we can't use
          * the more specific cluster api to claim bits. */
@@ -852,6 +858,8 @@ static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
                 goto bail;
         }
 
+        osb->la_last_gd = ac->ac_last_group;
+
         la->la_bm_off = cpu_to_le32(cluster_off);
         alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
         /* just in case... In the future when we find space ourselves,
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index d52100d49b6c..0462a7f4e21b 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -236,6 +236,7 @@ struct ocfs2_super
 
         enum ocfs2_local_alloc_state local_alloc_state;
         struct buffer_head *local_alloc_bh;
+        u64 la_last_gd;
 
         /* Next two fields are for local node slot recovery during
          * mount. */
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 7ac68cac041d..9d91e66f51a9 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -70,12 +70,6 @@ static int ocfs2_block_group_search(struct inode *inode,
                                     struct buffer_head *group_bh,
                                     u32 bits_wanted, u32 min_bits,
                                     u16 *bit_off, u16 *bits_found);
-static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
-                              u32 bits_wanted,
-                              u32 min_bits,
-                              u16 *bit_off,
-                              unsigned int *num_bits,
-                              u64 *bg_blkno);
 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
                                      struct ocfs2_alloc_context *ac,
                                      u32 bits_wanted,
@@ -1030,12 +1024,103 @@ static int ocfs2_block_group_search(struct inode *inode,
         return ret;
 }
 
+static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
+                                       struct ocfs2_journal_handle *handle,
+                                       struct buffer_head *di_bh,
+                                       u32 num_bits,
+                                       u16 chain)
+{
+        int ret;
+        u32 tmp_used;
+        struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
+        struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
+
+        ret = ocfs2_journal_access(handle, inode, di_bh,
+                                   OCFS2_JOURNAL_ACCESS_WRITE);
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto out;
+        }
+
+        tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
+        di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
+        le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
+
+        ret = ocfs2_journal_dirty(handle, di_bh);
+        if (ret < 0)
+                mlog_errno(ret);
+
+out:
+        return ret;
+}
+
+static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
+                                  u32 bits_wanted,
+                                  u32 min_bits,
+                                  u16 *bit_off,
+                                  unsigned int *num_bits,
+                                  u64 gd_blkno,
+                                  u16 *bits_left)
+{
+        int ret;
+        u16 found;
+        struct buffer_head *group_bh = NULL;
+        struct ocfs2_group_desc *gd;
+        struct inode *alloc_inode = ac->ac_inode;
+        struct ocfs2_journal_handle *handle = ac->ac_handle;
+
+        ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
+                               &group_bh, OCFS2_BH_CACHED, alloc_inode);
+        if (ret < 0) {
+                mlog_errno(ret);
+                return ret;
+        }
+
+        gd = (struct ocfs2_group_desc *) group_bh->b_data;
+        if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
+                OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
+                ret = -EIO;
+                goto out;
+        }
+
+        ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
+                                  bit_off, &found);
+        if (ret < 0) {
+                if (ret != -ENOSPC)
+                        mlog_errno(ret);
+                goto out;
+        }
+
+        *num_bits = found;
+
+        ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
+                                               *num_bits,
+                                               le16_to_cpu(gd->bg_chain));
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto out;
+        }
+
+        ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
+                                         *bit_off, *num_bits);
+        if (ret < 0)
+                mlog_errno(ret);
+
+        *bits_left = le16_to_cpu(gd->bg_free_bits_count);
+
+out:
+        brelse(group_bh);
+
+        return ret;
+}
+
 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
                               u32 bits_wanted,
                               u32 min_bits,
                               u16 *bit_off,
                               unsigned int *num_bits,
-                              u64 *bg_blkno)
+                              u64 *bg_blkno,
+                              u16 *bits_left)
 {
         int status;
         u16 chain, tmp_bits;
@@ -1173,6 +1258,7 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
              (unsigned long long)fe->i_blkno);
 
         *bg_blkno = le64_to_cpu(bg->bg_blkno);
+        *bits_left = le16_to_cpu(bg->bg_free_bits_count);
 bail:
         if (group_bh)
                 brelse(group_bh);
@@ -1194,6 +1280,8 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
 {
         int status;
         u16 victim, i;
+        u16 bits_left = 0;
+        u64 hint_blkno = ac->ac_last_group;
         struct ocfs2_chain_list *cl;
         struct ocfs2_dinode *fe;
 
@@ -1220,6 +1308,28 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
                 goto bail;
         }
 
+        if (hint_blkno) {
+                /* Attempt to short-circuit the usual search mechanism
+                 * by jumping straight to the most recently used
+                 * allocation group. This helps us mantain some
+                 * contiguousness across allocations. */
+                status = ocfs2_search_one_group(ac, bits_wanted, min_bits,
+                                                bit_off, num_bits,
+                                                hint_blkno, &bits_left);
+                if (!status) {
+                        /* Be careful to update *bg_blkno here as the
+                         * caller is expecting it to be filled in, and
+                         * ocfs2_search_one_group() won't do that for
+                         * us. */
+                        *bg_blkno = hint_blkno;
+                        goto set_hint;
+                }
+                if (status < 0 && status != -ENOSPC) {
+                        mlog_errno(status);
+                        goto bail;
+                }
+        }
+
         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
 
         victim = ocfs2_find_victim_chain(cl);
@@ -1227,9 +1337,9 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
         ac->ac_allow_chain_relink = 1;
 
         status = ocfs2_search_chain(ac, bits_wanted, min_bits, bit_off,
-                                    num_bits, bg_blkno);
+                                    num_bits, bg_blkno, &bits_left);
         if (!status)
-                goto bail;
+                goto set_hint;
         if (status < 0 && status != -ENOSPC) {
                 mlog_errno(status);
                 goto bail;
@@ -1251,8 +1361,8 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
 
                 ac->ac_chain = i;
                 status = ocfs2_search_chain(ac, bits_wanted, min_bits,
-                                            bit_off, num_bits,
-                                            bg_blkno);
+                                            bit_off, num_bits, bg_blkno,
+                                            &bits_left);
                 if (!status)
                         break;
                 if (status < 0 && status != -ENOSPC) {
@@ -1260,8 +1370,19 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
                         goto bail;
                 }
         }
-bail:
 
+set_hint:
+        if (status != -ENOSPC) {
+                /* If the next search of this group is not likely to
+                 * yield a suitable extent, then we reset the last
+                 * group hint so as to not waste a disk read */
+                if (bits_left < min_bits)
+                        ac->ac_last_group = 0;
+                else
+                        ac->ac_last_group = *bg_blkno;
+        }
+
+bail:
         mlog_exit(status);
         return status;
 }
@@ -1415,7 +1536,7 @@ int ocfs2_claim_clusters(struct ocfs2_super *osb,
 {
         int status;
         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
-        u64 bg_blkno;
+        u64 bg_blkno = 0;
         u16 bg_bit_off;
 
         mlog_entry_void();
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index a76c82a7ceac..c787838d1052 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -49,6 +49,8 @@ struct ocfs2_alloc_context {
         u16    ac_chain;
         int    ac_allow_chain_relink;
         group_search_t *ac_group_search;
+
+        u64    ac_last_group;
 };
 
 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac);