xfs: Replace per-ag array with a radix tree

[firefly-linux-kernel-4.4.55.git] / fs / xfs / xfs_mount.c

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index eb403b40e120d5f20661445b7fab21a58a8c31bd..c04dd83cb57c0b82b812f86c0c717ad220b79bc3 100644 (file)
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -209,13 +209,16 @@ STATIC void
 xfs_free_perag(
        xfs_mount_t     *mp)
 {
-       if (mp->m_perag) {
-               int     agno;
+       xfs_agnumber_t  agno;
+       struct xfs_perag *pag;
 
-               for (agno = 0; agno < mp->m_maxagi; agno++)
-                       if (mp->m_perag[agno].pagb_list)
-                               kmem_free(mp->m_perag[agno].pagb_list);
-               kmem_free(mp->m_perag);
+       for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
+               spin_lock(&mp->m_perag_lock);
+               pag = radix_tree_delete(&mp->m_perag_tree, agno);
+               spin_unlock(&mp->m_perag_lock);
+               ASSERT(pag);
+               kmem_free(pag->pagb_list);
+               kmem_free(pag);
        }
 }
 
@@ -389,10 +392,11 @@ xfs_initialize_perag_icache(
        }
 }
 
-xfs_agnumber_t
+int
 xfs_initialize_perag(
        xfs_mount_t     *mp,
-       xfs_agnumber_t  agcount)
+       xfs_agnumber_t  agcount,
+       xfs_agnumber_t  *maxagi)
 {
        xfs_agnumber_t  index, max_metadata;
        xfs_perag_t     *pag;
@@ -405,6 +409,33 @@ xfs_initialize_perag(
        agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
        ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
 
+       /*
+        * Walk the current per-ag tree so we don't try to initialise AGs
+        * that already exist (growfs case). Allocate and insert all the
+        * AGs we don't find ready for initialisation.
+        */
+       for (index = 0; index < agcount; index++) {
+               pag = xfs_perag_get(mp, index);
+               if (pag) {
+                       xfs_perag_put(pag);
+                       continue;
+               }
+               pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
+               if (!pag)
+                       return -ENOMEM;
+               if (radix_tree_preload(GFP_NOFS))
+                       return -ENOMEM;
+               spin_lock(&mp->m_perag_lock);
+               if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
+                       BUG();
+                       spin_unlock(&mp->m_perag_lock);
+                       kmem_free(pag);
+                       return -EEXIST;
+               }
+               spin_unlock(&mp->m_perag_lock);
+               radix_tree_preload_end();
+       }
+
        /* Clear the mount flag if no inode can overflow 32 bits
         * on this filesystem, or if specifically requested..
         */
@@ -438,21 +469,25 @@ xfs_initialize_perag(
                        }
 
                        /* This ag is preferred for inodes */
-                       pag = &mp->m_perag[index];
+                       pag = xfs_perag_get(mp, index);
                        pag->pagi_inodeok = 1;
                        if (index < max_metadata)
                                pag->pagf_metadata = 1;
                        xfs_initialize_perag_icache(pag);
+                       xfs_perag_put(pag);
                }
        } else {
                /* Setup default behavior for smaller filesystems */
                for (index = 0; index < agcount; index++) {
-                       pag = &mp->m_perag[index];
+                       pag = xfs_perag_get(mp, index);
                        pag->pagi_inodeok = 1;
                        xfs_initialize_perag_icache(pag);
+                       xfs_perag_put(pag);
                }
        }
-       return index;
+       if (maxagi)
+               *maxagi = index;
+       return 0;
 }
 
 void
@@ -731,12 +766,13 @@ xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
                error = xfs_ialloc_pagi_init(mp, NULL, index);
                if (error)
                        return error;
-               pag = &mp->m_perag[index];
+               pag = xfs_perag_get(mp, index);
                ifree += pag->pagi_freecount;
                ialloc += pag->pagi_count;
                bfree += pag->pagf_freeblks;
                bfreelst += pag->pagf_flcount;
                btree += pag->pagf_btreeblks;
+               xfs_perag_put(pag);
        }
        /*
         * Overwrite incore superblock counters with just-read data
@@ -1152,13 +1188,13 @@ xfs_mountfs(
        /*
         * Allocate and initialize the per-ag data.
         */
-       init_rwsem(&mp->m_peraglock);
-       mp->m_perag = kmem_zalloc(sbp->sb_agcount * sizeof(xfs_perag_t),
-                                 KM_MAYFAIL);
-       if (!mp->m_perag)
+       spin_lock_init(&mp->m_perag_lock);
+       INIT_RADIX_TREE(&mp->m_perag_tree, GFP_NOFS);
+       error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
+       if (error) {
+               cmn_err(CE_WARN, "XFS: Failed per-ag init: %d", error);
                goto out_remove_uuid;
-
-       mp->m_maxagi = xfs_initialize_perag(mp, sbp->sb_agcount);
+       }
 
        if (!sbp->sb_logblocks) {
                cmn_err(CE_WARN, "XFS: no log defined");