afs: Fix order-1 allocation in afs_do_lookup()

afs_do_lookup() will do an order-1 allocation to allocate status records if
there are more than 39 vnodes to stat.

Fix this by allocating an array of {status,callback} records for each vnode
we want to examine using vmalloc() if larger than a page.

This not only gets rid of the order-1 allocation, but makes it easier to
grow beyond 50 records for YFS servers.  It also allows us to move to
{status,callback} tuples for other calls too and makes it easier to lock
across the application of the status and the callback to the vnode.

Fixes: 5cf9dd55a0ec ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 16 insertions, 21 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index c15550310f62..0f14bcfe233d 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -102,8 +102,7 @@ struct afs_lookup_cookie {
         bool                    found;
         bool                    one_only;
         unsigned short          nr_fids;
-        struct afs_file_status  *statuses;
-        struct afs_callback     *callbacks;
+        struct afs_status_cb    *statuses;
         struct afs_fid          fids[50];
 };
 
@@ -640,6 +639,7 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
         struct afs_lookup_cookie *cookie;
         struct afs_cb_interest *cbi = NULL;
         struct afs_super_info *as = dir->i_sb->s_fs_info;
+        struct afs_status_cb *scb;
         struct afs_iget_data data;
         struct afs_fs_cursor fc;
         struct afs_vnode *dvnode = AFS_FS_I(dir);
@@ -686,16 +686,11 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
 
         /* Need space for examining all the selected files */
         inode = ERR_PTR(-ENOMEM);
-        cookie->statuses = kcalloc(cookie->nr_fids, sizeof(struct afs_file_status),
-                                   GFP_KERNEL);
+        cookie->statuses = kvcalloc(cookie->nr_fids, sizeof(struct afs_status_cb),
+                                    GFP_KERNEL);
         if (!cookie->statuses)
                 goto out;
 
-        cookie->callbacks = kcalloc(cookie->nr_fids, sizeof(struct afs_callback),
-                                    GFP_KERNEL);
-        if (!cookie->callbacks)
-                goto out_s;
-
         /* Try FS.InlineBulkStatus first.  Abort codes for the individual
          * lookups contained therein are stored in the reply without aborting
          * the whole operation.
@@ -716,7 +711,6 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
                                                   afs_v2net(dvnode),
                                                   cookie->fids,
                                                   cookie->statuses,
-                                                  cookie->callbacks,
                                                   cookie->nr_fids, NULL);
                 }
 
@@ -741,11 +735,12 @@ no_inline_bulk_status:
         inode = ERR_PTR(-ERESTARTSYS);
         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
                 while (afs_select_fileserver(&fc)) {
+                        scb = &cookie->statuses[0];
                         afs_fs_fetch_status(&fc,
                                             afs_v2net(dvnode),
                                             cookie->fids,
-                                            cookie->statuses,
-                                            cookie->callbacks,
+                                            &scb->status,
+                                            &scb->callback,
                                             NULL);
                 }
 
@@ -758,24 +753,26 @@ no_inline_bulk_status:
                 goto out_c;
 
         for (i = 0; i < cookie->nr_fids; i++)
-                cookie->statuses[i].abort_code = 0;
+                cookie->statuses[i].status.abort_code = 0;
 
 success:
         /* Turn all the files into inodes and save the first one - which is the
          * one we actually want.
          */
-        if (cookie->statuses[0].abort_code != 0)
-                inode = ERR_PTR(afs_abort_to_error(cookie->statuses[0].abort_code));
+        scb = &cookie->statuses[0];
+        if (scb->status.abort_code != 0)
+                inode = ERR_PTR(afs_abort_to_error(scb->status.abort_code));
 
         for (i = 0; i < cookie->nr_fids; i++) {
+                struct afs_status_cb *scb = &cookie->statuses[i];
                 struct inode *ti;
 
-                if (cookie->statuses[i].abort_code != 0)
+                if (scb->status.abort_code != 0)
                         continue;
 
                 ti = afs_iget(dir->i_sb, key, &cookie->fids[i],
-                              &cookie->statuses[i],
-                              &cookie->callbacks[i],
+                              &scb->status,
+                              &scb->callback,
                               cbi, dvnode);
                 if (i == 0) {
                         inode = ti;
@@ -787,9 +784,7 @@ success:
 
 out_c:
         afs_put_cb_interest(afs_v2net(dvnode), cbi);
-        kfree(cookie->callbacks);
-out_s:
-        kfree(cookie->statuses);
+        kvfree(cookie->statuses);
 out:
         kfree(cookie);
         return inode;