[XFS] replace vn_get usage by ihold

SGI-PV: 938306
SGI-Modid: xfs-linux:xfs-kern:194627a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

4 files changed, 15 insertions, 82 deletions

diff --git a/fs/xfs/linux-2.6/xfs_vnode.c b/fs/xfs/linux-2.6/xfs_vnode.c
index 250cad54e892..353276bda344 100644
--- a/fs/xfs/linux-2.6/xfs_vnode.c
+++ b/fs/xfs/linux-2.6/xfs_vnode.c
@@ -163,30 +163,6 @@ vn_initialize(
 }
 
 /*
- * Get a reference on a vnode.
- */
-vnode_t *
-vn_get(
-        struct vnode    *vp,
-        vmap_t          *vmap)
-{
-        struct inode    *inode;
-
-        XFS_STATS_INC(vn_get);
-        inode = LINVFS_GET_IP(vp);
-        if (inode->i_state & I_FREEING)
-                return NULL;
-
-        inode = ilookup(vmap->v_vfsp->vfs_super, vmap->v_ino);
-        if (!inode)     /* Inode not present */
-                return NULL;
-
-        vn_trace_exit(vp, "vn_get", (inst_t *)__return_address);
-
-        return vp;
-}
-
-/*
  * Revalidate the Linux inode from the vattr.
  * Note: i_size _not_ updated; we must hold the inode
  * semaphore when doing that - callers responsibility.
diff --git a/fs/xfs/linux-2.6/xfs_vnode.h b/fs/xfs/linux-2.6/xfs_vnode.h
index 56d85d85fb05..6cb0a01df25d 100644
--- a/fs/xfs/linux-2.6/xfs_vnode.h
+++ b/fs/xfs/linux-2.6/xfs_vnode.h
@@ -505,20 +505,6 @@ extern int	vn_wait(struct vnode *);
 extern vnode_t  *vn_initialize(struct inode *);
 
 /*
- * Acquiring and invalidating vnodes:
- *
- *      if (vn_get(vp, version, 0))
- *              ...;
- *      vn_purge(vp, version);
- *
- * vn_get and vn_purge must be called with vmap_t arguments, sampled
- * while a lock that the vnode's VOP_RECLAIM function acquires is
- * held, to ensure that the vnode sampled with the lock held isn't
- * recycled (VOP_RECLAIMed) or deallocated between the release of the lock
- * and the subsequent vn_get or vn_purge.
- */
-
-/*
  * vnode_map structures _must_ match vn_epoch and vnode structure sizes.
  */
 typedef struct vnode_map {
@@ -532,7 +518,6 @@ typedef struct vnode_map {
                          (vmap).v_ino    = (vp)->v_inode.i_ino; }
 
 extern void     vn_purge(struct vnode *, vmap_t *);
-extern vnode_t  *vn_get(struct vnode *, vmap_t *);
 extern int      vn_revalidate(struct vnode *);
 extern void     vn_revalidate_core(struct vnode *, vattr_t *);
 extern void     vn_remove(struct vnode *);
@@ -560,6 +545,12 @@ extern void	vn_rele(struct vnode *);
 #define VN_RELE(vp)             (iput(LINVFS_GET_IP(vp)))
 #endif
 
+static inline struct vnode *vn_grab(struct vnode *vp)
+{
+        struct inode *inode = igrab(LINVFS_GET_IP(vp));
+        return inode ? LINVFS_GET_VP(inode) : NULL;
+}
+
 /*
  * Vname handling macros.
  */
diff --git a/fs/xfs/quota/xfs_qm_syscalls.c b/fs/xfs/quota/xfs_qm_syscalls.c
index 68e98962dbef..15e02e8a9d4f 100644
--- a/fs/xfs/quota/xfs_qm_syscalls.c
+++ b/fs/xfs/quota/xfs_qm_syscalls.c
@@ -1053,7 +1053,6 @@ xfs_qm_dqrele_all_inodes(
         struct xfs_mount *mp,
         uint             flags)
 {
-        vmap_t          vmap;
         xfs_inode_t     *ip, *topino;
         uint            ireclaims;
         vnode_t         *vp;
@@ -1061,8 +1060,8 @@ xfs_qm_dqrele_all_inodes(
 
         ASSERT(mp->m_quotainfo);
 
-again:
         XFS_MOUNT_ILOCK(mp);
+again:
         ip = mp->m_inodes;
         if (ip == NULL) {
                 XFS_MOUNT_IUNLOCK(mp);
@@ -1090,18 +1089,14 @@ again:
                 }
                 vnode_refd = B_FALSE;
                 if (xfs_ilock_nowait(ip, XFS_ILOCK_EXCL) == 0) {
-                        /*
-                         * Sample vp mapping while holding the mplock, lest
-                         * we come across a non-existent vnode.
-                         */
-                        VMAP(vp, vmap);
                         ireclaims = mp->m_ireclaims;
                         topino = mp->m_inodes;
-                        XFS_MOUNT_IUNLOCK(mp);
+                        vp = vn_grab(vp);
+                        if (!vp)
+                                goto again;
 
+                        XFS_MOUNT_IUNLOCK(mp);
                         /* XXX restart limit ? */
-                        if ( ! (vp = vn_get(vp, &vmap)))
-                                goto again;
                         xfs_ilock(ip, XFS_ILOCK_EXCL);
                         vnode_refd = B_TRUE;
                 } else {
@@ -1137,7 +1132,6 @@ again:
                  */
                 if (topino != mp->m_inodes || mp->m_ireclaims != ireclaims) {
                         /* XXX use a sentinel */
-                        XFS_MOUNT_IUNLOCK(mp);
                         goto again;
                 }
                 ip = ip->i_mnext;
diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c
index 42bcc0215203..b8ce6cad2b71 100644
--- a/fs/xfs/xfs_vfsops.c
+++ b/fs/xfs/xfs_vfsops.c
@@ -906,7 +906,6 @@ xfs_sync_inodes(
         xfs_inode_t     *ip_next;
         xfs_buf_t       *bp;
         vnode_t         *vp = NULL;
-        vmap_t          vmap;
         int             error;
         int             last_error;
         uint64_t        fflag;
@@ -1101,48 +1100,21 @@ xfs_sync_inodes(
                  * lock in xfs_ireclaim() after the inode is pulled from
                  * the mount list will sleep until we release it here.
                  * This keeps the vnode from being freed while we reference
-                 * it.  It is also cheaper and simpler than actually doing
-                 * a vn_get() for every inode we touch here.
+                 * it.
                  */
                 if (xfs_ilock_nowait(ip, lock_flags) == 0) {
-
                         if ((flags & SYNC_BDFLUSH) || (vp == NULL)) {
                                 ip = ip->i_mnext;
                                 continue;
                         }
 
-                        /*
-                         * We need to unlock the inode list lock in order
-                         * to lock the inode. Insert a marker record into
-                         * the inode list to remember our position, dropping
-                         * the lock is now done inside the IPOINTER_INSERT
-                         * macro.
-                         *
-                         * We also use the inode list lock to protect us
-                         * in taking a snapshot of the vnode version number
-                         * for use in calling vn_get().
-                         */
-                        VMAP(vp, vmap);
-                        IPOINTER_INSERT(ip, mp);
-
-                        vp = vn_get(vp, &vmap);
+                        vp = vn_grab(vp);
                         if (vp == NULL) {
-                                /*
-                                 * The vnode was reclaimed once we let go
-                                 * of the inode list lock.  Skip to the
-                                 * next list entry. Remove the marker.
-                                 */
-
-                                XFS_MOUNT_ILOCK(mp);
-
-                                mount_locked = B_TRUE;
-                                vnode_refed  = B_FALSE;
-
-                                IPOINTER_REMOVE(ip, mp);
-
+                                ip = ip->i_mnext;
                                 continue;
                         }
 
+                        IPOINTER_INSERT(ip, mp);
                         xfs_ilock(ip, lock_flags);
 
                         ASSERT(vp == XFS_ITOV(ip));