Merge branch 'topic/oss' into for-linus
[pandora-kernel.git] / fs / xfs / xfs_iget.c
index 5fcec6f..ecbf8b4 100644 (file)
@@ -64,6 +64,10 @@ xfs_inode_alloc(
        ip = kmem_zone_alloc(xfs_inode_zone, KM_SLEEP);
        if (!ip)
                return NULL;
+       if (inode_init_always(mp->m_super, VFS_I(ip))) {
+               kmem_zone_free(xfs_inode_zone, ip);
+               return NULL;
+       }
 
        ASSERT(atomic_read(&ip->i_iocount) == 0);
        ASSERT(atomic_read(&ip->i_pincount) == 0);
@@ -105,17 +109,6 @@ xfs_inode_alloc(
 #ifdef XFS_DIR2_TRACE
        ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_NOFS);
 #endif
-       /*
-       * Now initialise the VFS inode. We do this after the xfs_inode
-       * initialisation as internal failures will result in ->destroy_inode
-       * being called and that will pass down through the reclaim path and
-       * free the XFS inode. This path requires the XFS inode to already be
-       * initialised. Hence if this call fails, the xfs_inode has already
-       * been freed and we should not reference it at all in the error
-       * handling.
-       */
-       if (!inode_init_always(mp->m_super, VFS_I(ip)))
-               return NULL;
 
        /* prevent anyone from using this yet */
        VFS_I(ip)->i_state = I_NEW|I_LOCK;
@@ -123,6 +116,71 @@ xfs_inode_alloc(
        return ip;
 }
 
+STATIC void
+xfs_inode_free(
+       struct xfs_inode        *ip)
+{
+       switch (ip->i_d.di_mode & S_IFMT) {
+       case S_IFREG:
+       case S_IFDIR:
+       case S_IFLNK:
+               xfs_idestroy_fork(ip, XFS_DATA_FORK);
+               break;
+       }
+
+       if (ip->i_afp)
+               xfs_idestroy_fork(ip, XFS_ATTR_FORK);
+
+#ifdef XFS_INODE_TRACE
+       ktrace_free(ip->i_trace);
+#endif
+#ifdef XFS_BMAP_TRACE
+       ktrace_free(ip->i_xtrace);
+#endif
+#ifdef XFS_BTREE_TRACE
+       ktrace_free(ip->i_btrace);
+#endif
+#ifdef XFS_RW_TRACE
+       ktrace_free(ip->i_rwtrace);
+#endif
+#ifdef XFS_ILOCK_TRACE
+       ktrace_free(ip->i_lock_trace);
+#endif
+#ifdef XFS_DIR2_TRACE
+       ktrace_free(ip->i_dir_trace);
+#endif
+
+       if (ip->i_itemp) {
+               /*
+                * Only if we are shutting down the fs will we see an
+                * inode still in the AIL. If it is there, we should remove
+                * it to prevent a use-after-free from occurring.
+                */
+               xfs_log_item_t  *lip = &ip->i_itemp->ili_item;
+               struct xfs_ail  *ailp = lip->li_ailp;
+
+               ASSERT(((lip->li_flags & XFS_LI_IN_AIL) == 0) ||
+                                      XFS_FORCED_SHUTDOWN(ip->i_mount));
+               if (lip->li_flags & XFS_LI_IN_AIL) {
+                       spin_lock(&ailp->xa_lock);
+                       if (lip->li_flags & XFS_LI_IN_AIL)
+                               xfs_trans_ail_delete(ailp, lip);
+                       else
+                               spin_unlock(&ailp->xa_lock);
+               }
+               xfs_inode_item_destroy(ip);
+               ip->i_itemp = NULL;
+       }
+
+       /* asserts to verify all state is correct here */
+       ASSERT(atomic_read(&ip->i_iocount) == 0);
+       ASSERT(atomic_read(&ip->i_pincount) == 0);
+       ASSERT(!spin_is_locked(&ip->i_flags_lock));
+       ASSERT(completion_done(&ip->i_flush));
+
+       kmem_zone_free(xfs_inode_zone, ip);
+}
+
 /*
  * Check the validity of the inode we just found it the cache
  */
@@ -133,80 +191,82 @@ xfs_iget_cache_hit(
        int                     flags,
        int                     lock_flags) __releases(pag->pag_ici_lock)
 {
+       struct inode            *inode = VFS_I(ip);
        struct xfs_mount        *mp = ip->i_mount;
-       int                     error = EAGAIN;
+       int                     error;
+
+       spin_lock(&ip->i_flags_lock);
 
        /*
-        * If INEW is set this inode is being set up
-        * If IRECLAIM is set this inode is being torn down
-        * Pause and try again.
+        * If we are racing with another cache hit that is currently
+        * instantiating this inode or currently recycling it out of
+        * reclaimabe state, wait for the initialisation to complete
+        * before continuing.
+        *
+        * XXX(hch): eventually we should do something equivalent to
+        *           wait_on_inode to wait for these flags to be cleared
+        *           instead of polling for it.
         */
-       if (xfs_iflags_test(ip, (XFS_INEW|XFS_IRECLAIM))) {
+       if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
                XFS_STATS_INC(xs_ig_frecycle);
+               error = EAGAIN;
                goto out_error;
        }
 
-       /* If IRECLAIMABLE is set, we've torn down the vfs inode part */
-       if (xfs_iflags_test(ip, XFS_IRECLAIMABLE)) {
-
-               /*
-                * If lookup is racing with unlink, then we should return an
-                * error immediately so we don't remove it from the reclaim
-                * list and potentially leak the inode.
-                */
-               if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
-                       error = ENOENT;
-                       goto out_error;
-               }
+       /*
+        * If lookup is racing with unlink return an error immediately.
+        */
+       if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
+               error = ENOENT;
+               goto out_error;
+       }
 
+       /*
+        * If IRECLAIMABLE is set, we've torn down the VFS inode already.
+        * Need to carefully get it back into useable state.
+        */
+       if (ip->i_flags & XFS_IRECLAIMABLE) {
                xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
 
                /*
-                * We need to re-initialise the VFS inode as it has been
-                * 'freed' by the VFS. Do this here so we can deal with
-                * errors cleanly, then tag it so it can be set up correctly
-                * later.
+                * We need to set XFS_INEW atomically with clearing the
+                * reclaimable tag so that we do have an indicator of the
+                * inode still being initialized.
                 */
-               if (!inode_init_always(mp->m_super, VFS_I(ip))) {
-                       error = ENOMEM;
-                       goto out_error;
-               }
+               ip->i_flags |= XFS_INEW;
+               ip->i_flags &= ~XFS_IRECLAIMABLE;
+               __xfs_inode_clear_reclaim_tag(mp, pag, ip);
 
-               /*
-                * We must set the XFS_INEW flag before clearing the
-                * XFS_IRECLAIMABLE flag so that if a racing lookup does
-                * not find the XFS_IRECLAIMABLE above but has the igrab()
-                * below succeed we can safely check XFS_INEW to detect
-                * that this inode is still being initialised.
-                */
-               xfs_iflags_set(ip, XFS_INEW);
-               xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
+               spin_unlock(&ip->i_flags_lock);
+               read_unlock(&pag->pag_ici_lock);
 
-               /* clear the radix tree reclaim flag as well. */
-               __xfs_inode_clear_reclaim_tag(mp, pag, ip);
-       } else if (!igrab(VFS_I(ip))) {
+               error = -inode_init_always(mp->m_super, inode);
+               if (error) {
+                       /*
+                        * Re-initializing the inode failed, and we are in deep
+                        * trouble.  Try to re-add it to the reclaim list.
+                        */
+                       read_lock(&pag->pag_ici_lock);
+                       spin_lock(&ip->i_flags_lock);
+
+                       ip->i_flags &= ~XFS_INEW;
+                       ip->i_flags |= XFS_IRECLAIMABLE;
+                       __xfs_inode_set_reclaim_tag(pag, ip);
+                       goto out_error;
+               }
+               inode->i_state = I_LOCK|I_NEW;
+       } else {
                /* If the VFS inode is being torn down, pause and try again. */
-               XFS_STATS_INC(xs_ig_frecycle);
-               goto out_error;
-       } else if (xfs_iflags_test(ip, XFS_INEW)) {
-               /*
-                * We are racing with another cache hit that is
-                * currently recycling this inode out of the XFS_IRECLAIMABLE
-                * state. Wait for the initialisation to complete before
-                * continuing.
-                */
-               wait_on_inode(VFS_I(ip));
-       }
+               if (!igrab(inode)) {
+                       error = EAGAIN;
+                       goto out_error;
+               }
 
-       if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
-               error = ENOENT;
-               iput(VFS_I(ip));
-               goto out_error;
+               /* We've got a live one. */
+               spin_unlock(&ip->i_flags_lock);
+               read_unlock(&pag->pag_ici_lock);
        }
 
-       /* We've got a live one. */
-       read_unlock(&pag->pag_ici_lock);
-
        if (lock_flags != 0)
                xfs_ilock(ip, lock_flags);
 
@@ -216,6 +276,7 @@ xfs_iget_cache_hit(
        return 0;
 
 out_error:
+       spin_unlock(&ip->i_flags_lock);
        read_unlock(&pag->pag_ici_lock);
        return error;
 }
@@ -299,7 +360,8 @@ out_preload_end:
        if (lock_flags)
                xfs_iunlock(ip, lock_flags);
 out_destroy:
-       xfs_destroy_inode(ip);
+       __destroy_inode(VFS_I(ip));
+       xfs_inode_free(ip);
        return error;
 }
 
@@ -504,62 +566,7 @@ xfs_ireclaim(
        xfs_qm_dqdetach(ip);
        xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
 
-       switch (ip->i_d.di_mode & S_IFMT) {
-       case S_IFREG:
-       case S_IFDIR:
-       case S_IFLNK:
-               xfs_idestroy_fork(ip, XFS_DATA_FORK);
-               break;
-       }
-
-       if (ip->i_afp)
-               xfs_idestroy_fork(ip, XFS_ATTR_FORK);
-
-#ifdef XFS_INODE_TRACE
-       ktrace_free(ip->i_trace);
-#endif
-#ifdef XFS_BMAP_TRACE
-       ktrace_free(ip->i_xtrace);
-#endif
-#ifdef XFS_BTREE_TRACE
-       ktrace_free(ip->i_btrace);
-#endif
-#ifdef XFS_RW_TRACE
-       ktrace_free(ip->i_rwtrace);
-#endif
-#ifdef XFS_ILOCK_TRACE
-       ktrace_free(ip->i_lock_trace);
-#endif
-#ifdef XFS_DIR2_TRACE
-       ktrace_free(ip->i_dir_trace);
-#endif
-       if (ip->i_itemp) {
-               /*
-                * Only if we are shutting down the fs will we see an
-                * inode still in the AIL. If it is there, we should remove
-                * it to prevent a use-after-free from occurring.
-                */
-               xfs_log_item_t  *lip = &ip->i_itemp->ili_item;
-               struct xfs_ail  *ailp = lip->li_ailp;
-
-               ASSERT(((lip->li_flags & XFS_LI_IN_AIL) == 0) ||
-                                      XFS_FORCED_SHUTDOWN(ip->i_mount));
-               if (lip->li_flags & XFS_LI_IN_AIL) {
-                       spin_lock(&ailp->xa_lock);
-                       if (lip->li_flags & XFS_LI_IN_AIL)
-                               xfs_trans_ail_delete(ailp, lip);
-                       else
-                               spin_unlock(&ailp->xa_lock);
-               }
-               xfs_inode_item_destroy(ip);
-               ip->i_itemp = NULL;
-       }
-       /* asserts to verify all state is correct here */
-       ASSERT(atomic_read(&ip->i_iocount) == 0);
-       ASSERT(atomic_read(&ip->i_pincount) == 0);
-       ASSERT(!spin_is_locked(&ip->i_flags_lock));
-       ASSERT(completion_done(&ip->i_flush));
-       kmem_zone_free(xfs_inode_zone, ip);
+       xfs_inode_free(ip);
 }
 
 /*