Conserve stack in zfs_sa_upgrade()

As always under Linux stack space is at a premium.  Relocate two
20 element sa_bulk_attr_t arrays in zfs_sa_upgrade() from the stack
to the heap.

diff --git a/module/zfs/zfs_sa.c b/module/zfs/zfs_sa.c
index f4c599f..68bce0a 100644 (file)
--- a/module/zfs/zfs_sa.c
+++ b/module/zfs/zfs_sa.c
@@ -199,9 +199,8 @@ zfs_sa_upgrade(sa_handle_t *hdl, dmu_tx_t *tx)
        dmu_buf_t *db = sa_get_db(hdl);
        znode_t *zp = sa_get_userdata(hdl);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
-       sa_bulk_attr_t bulk[20];
        int count = 0;
-       sa_bulk_attr_t sa_attrs[20] = { 0 };
+       sa_bulk_attr_t *bulk, *sa_attrs;
        zfs_acl_locator_cb_t locate = { 0 };
        uint64_t uid, gid, mode, rdev, xattr, parent;
        uint64_t crtime[2], mtime[2], ctime[2];
@@ -237,6 +236,7 @@ zfs_sa_upgrade(sa_handle_t *hdl, dmu_tx_t *tx)
        }
 
        /* First do a bulk query of the attributes that aren't cached */
+       bulk = kmem_alloc(sizeof(sa_bulk_attr_t) * 20, KM_SLEEP);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CRTIME(zfsvfs), NULL, &crtime, 16);
@@ -249,15 +249,17 @@ zfs_sa_upgrade(sa_handle_t *hdl, dmu_tx_t *tx)
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ZNODE_ACL(zfsvfs), NULL,
            &znode_acl, 88);
 
-       if (sa_bulk_lookup_locked(hdl, bulk, count) != 0)
+       if (sa_bulk_lookup_locked(hdl, bulk, count) != 0) {
+               kmem_free(bulk, sizeof(sa_bulk_attr_t) * 20);
                goto done;
-
+       }
 
        /*
         * While the order here doesn't matter its best to try and organize
         * it is such a way to pick up an already existing layout number
         */
        count = 0;
+       sa_attrs = kmem_zalloc(sizeof(sa_bulk_attr_t) * 20, KM_SLEEP);
        SA_ADD_BULK_ATTR(sa_attrs, count, SA_ZPL_MODE(zfsvfs), NULL, &mode, 8);
        SA_ADD_BULK_ATTR(sa_attrs, count, SA_ZPL_SIZE(zfsvfs), NULL,
            &zp->z_size, 8);
@@ -316,6 +318,8 @@ zfs_sa_upgrade(sa_handle_t *hdl, dmu_tx_t *tx)
                    znode_acl.z_acl_extern_obj, tx));
 
        zp->z_is_sa = B_TRUE;
+       kmem_free(sa_attrs, sizeof(sa_bulk_attr_t) * 20);
+       kmem_free(bulk, sizeof(sa_bulk_attr_t) * 20);
 done:
        if (drop_lock)
                mutex_exit(&zp->z_lock);