#include <linux/kthread.h>
#include <linux/freezer.h>
+STATIC void __xfs_inode_clear_reclaim_tag(struct xfs_mount *mp,
+ struct xfs_perag *pag, struct xfs_inode *ip);
+
+/*
+ * Allocate and initialise an xfs_inode.
+ */
+STATIC struct xfs_inode *
+xfs_inode_alloc(
+ struct xfs_mount *mp,
+ xfs_ino_t ino)
+{
+ struct xfs_inode *ip;
+
+ /*
+ * if this didn't occur in transactions, we could use
+ * KM_MAYFAIL and return NULL here on ENOMEM. Set the
+ * code up to do this anyway.
+ */
+ 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_pincount) == 0);
+ ASSERT(!spin_is_locked(&ip->i_flags_lock));
+ ASSERT(!xfs_isiflocked(ip));
+ ASSERT(ip->i_ino == 0);
+
+ mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
+
+ /* initialise the xfs inode */
+ ip->i_ino = ino;
+ ip->i_mount = mp;
+ memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
+ ip->i_afp = NULL;
+ memset(&ip->i_df, 0, sizeof(xfs_ifork_t));
+ ip->i_flags = 0;
+ ip->i_delayed_blks = 0;
+ memset(&ip->i_d, 0, sizeof(xfs_icdinode_t));
+
+ return ip;
+}
+
+STATIC void
+xfs_inode_free_callback(
+ struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct xfs_inode *ip = XFS_I(inode);
+
+ kmem_zone_free(xfs_inode_zone, 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);
+
+ if (ip->i_itemp) {
+ ASSERT(!(ip->i_itemp->ili_item.li_flags & XFS_LI_IN_AIL));
+ xfs_inode_item_destroy(ip);
+ ip->i_itemp = NULL;
+ }
+
+ /* asserts to verify all state is correct here */
+ ASSERT(atomic_read(&ip->i_pincount) == 0);
+ ASSERT(!spin_is_locked(&ip->i_flags_lock));
+ ASSERT(!xfs_isiflocked(ip));
+
+ /*
+ * Because we use RCU freeing we need to ensure the inode always
+ * appears to be reclaimed with an invalid inode number when in the
+ * free state. The ip->i_flags_lock provides the barrier against lookup
+ * races.
+ */
+ spin_lock(&ip->i_flags_lock);
+ ip->i_flags = XFS_IRECLAIM;
+ ip->i_ino = 0;
+ spin_unlock(&ip->i_flags_lock);
+
+ call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
+}
+
+/*
+ * Check the validity of the inode we just found it the cache
+ */
+static int
+xfs_iget_cache_hit(
+ struct xfs_perag *pag,
+ struct xfs_inode *ip,
+ xfs_ino_t ino,
+ int flags,
+ int lock_flags) __releases(RCU)
+{
+ struct inode *inode = VFS_I(ip);
+ struct xfs_mount *mp = ip->i_mount;
+ int error;
+
+ /*
+ * check for re-use of an inode within an RCU grace period due to the
+ * radix tree nodes not being updated yet. We monitor for this by
+ * setting the inode number to zero before freeing the inode structure.
+ * If the inode has been reallocated and set up, then the inode number
+ * will not match, so check for that, too.
+ */
+ spin_lock(&ip->i_flags_lock);
+ if (ip->i_ino != ino) {
+ trace_xfs_iget_skip(ip);
+ XFS_STATS_INC(xs_ig_frecycle);
+ error = EAGAIN;
+ goto out_error;
+ }
+
+
+ /*
+ * 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 (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
+ trace_xfs_iget_skip(ip);
+ XFS_STATS_INC(xs_ig_frecycle);
+ error = EAGAIN;
+ 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) {
+ trace_xfs_iget_reclaim(ip);
+
+ /*
+ * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
+ * from stomping over us while we recycle the inode. We can't
+ * clear the radix tree reclaimable tag yet as it requires
+ * pag_ici_lock to be held exclusive.
+ */
+ ip->i_flags |= XFS_IRECLAIM;
+
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+
+ 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.
+ */
+ rcu_read_lock();
+ spin_lock(&ip->i_flags_lock);
+
+ ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
+ ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
+ trace_xfs_iget_reclaim_fail(ip);
+ goto out_error;
+ }
+
+ spin_lock(&pag->pag_ici_lock);
+ spin_lock(&ip->i_flags_lock);
+
+ /*
+ * Clear the per-lifetime state in the inode as we are now
+ * effectively a new inode and need to return to the initial
+ * state before reuse occurs.
+ */
+ ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
+ ip->i_flags |= XFS_INEW;
+ __xfs_inode_clear_reclaim_tag(mp, pag, ip);
+ inode->i_state = I_NEW;
+
+ ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));
+ mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
+
+ spin_unlock(&ip->i_flags_lock);
+ spin_unlock(&pag->pag_ici_lock);
+ } else {
+ /* If the VFS inode is being torn down, pause and try again. */
+ if (!igrab(inode)) {
+ trace_xfs_iget_skip(ip);
+ error = EAGAIN;
+ goto out_error;
+ }
+
+ /* We've got a live one. */
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+ trace_xfs_iget_hit(ip);
+ }
+
+ if (lock_flags != 0)
+ xfs_ilock(ip, lock_flags);
+
+ xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE);
+ XFS_STATS_INC(xs_ig_found);
+
+ return 0;
+
+out_error:
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+ return error;
+}
+
+
+static int
+xfs_iget_cache_miss(
+ struct xfs_mount *mp,
+ struct xfs_perag *pag,
+ xfs_trans_t *tp,
+ xfs_ino_t ino,
+ struct xfs_inode **ipp,
+ int flags,
+ int lock_flags)
+{
+ struct xfs_inode *ip;
+ int error;
+ xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
+ int iflags;
+
+ ip = xfs_inode_alloc(mp, ino);
+ if (!ip)
+ return ENOMEM;
+
+ error = xfs_iread(mp, tp, ip, flags);
+ if (error)
+ goto out_destroy;
+
+ trace_xfs_iget_miss(ip);
+
+ if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
+ error = ENOENT;
+ goto out_destroy;
+ }
+
+ /*
+ * Preload the radix tree so we can insert safely under the
+ * write spinlock. Note that we cannot sleep inside the preload
+ * region. Since we can be called from transaction context, don't
+ * recurse into the file system.
+ */
+ if (radix_tree_preload(GFP_NOFS)) {
+ error = EAGAIN;
+ goto out_destroy;
+ }
+
+ /*
+ * Because the inode hasn't been added to the radix-tree yet it can't
+ * be found by another thread, so we can do the non-sleeping lock here.
+ */
+ if (lock_flags) {
+ if (!xfs_ilock_nowait(ip, lock_flags))
+ BUG();
+ }
+
+ /*
+ * These values must be set before inserting the inode into the radix
+ * tree as the moment it is inserted a concurrent lookup (allowed by the
+ * RCU locking mechanism) can find it and that lookup must see that this
+ * is an inode currently under construction (i.e. that XFS_INEW is set).
+ * The ip->i_flags_lock that protects the XFS_INEW flag forms the
+ * memory barrier that ensures this detection works correctly at lookup
+ * time.
+ */
+ iflags = XFS_INEW;
+ if (flags & XFS_IGET_DONTCACHE)
+ iflags |= XFS_IDONTCACHE;
+ ip->i_udquot = ip->i_gdquot = NULL;
+ xfs_iflags_set(ip, iflags);
+
+ /* insert the new inode */
+ spin_lock(&pag->pag_ici_lock);
+ error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
+ if (unlikely(error)) {
+ WARN_ON(error != -EEXIST);
+ XFS_STATS_INC(xs_ig_dup);
+ error = EAGAIN;
+ goto out_preload_end;
+ }
+ spin_unlock(&pag->pag_ici_lock);
+ radix_tree_preload_end();
+
+ *ipp = ip;
+ return 0;
+
+out_preload_end:
+ spin_unlock(&pag->pag_ici_lock);
+ radix_tree_preload_end();
+ if (lock_flags)
+ xfs_iunlock(ip, lock_flags);
+out_destroy:
+ __destroy_inode(VFS_I(ip));
+ xfs_inode_free(ip);
+ return error;
+}
+
+/*
+ * Look up an inode by number in the given file system.
+ * The inode is looked up in the cache held in each AG.
+ * If the inode is found in the cache, initialise the vfs inode
+ * if necessary.
+ *
+ * If it is not in core, read it in from the file system's device,
+ * add it to the cache and initialise the vfs inode.
+ *
+ * The inode is locked according to the value of the lock_flags parameter.
+ * This flag parameter indicates how and if the inode's IO lock and inode lock
+ * should be taken.
+ *
+ * mp -- the mount point structure for the current file system. It points
+ * to the inode hash table.
+ * tp -- a pointer to the current transaction if there is one. This is
+ * simply passed through to the xfs_iread() call.
+ * ino -- the number of the inode desired. This is the unique identifier
+ * within the file system for the inode being requested.
+ * lock_flags -- flags indicating how to lock the inode. See the comment
+ * for xfs_ilock() for a list of valid values.
+ */
+int
+xfs_iget(
+ xfs_mount_t *mp,
+ xfs_trans_t *tp,
+ xfs_ino_t ino,
+ uint flags,
+ uint lock_flags,
+ xfs_inode_t **ipp)
+{
+ xfs_inode_t *ip;
+ int error;
+ xfs_perag_t *pag;
+ xfs_agino_t agino;
+
+ /*
+ * xfs_reclaim_inode() uses the ILOCK to ensure an inode
+ * doesn't get freed while it's being referenced during a
+ * radix tree traversal here. It assumes this function
+ * aqcuires only the ILOCK (and therefore it has no need to
+ * involve the IOLOCK in this synchronization).
+ */
+ ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);
+
+ /* reject inode numbers outside existing AGs */
+ if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
+ return EINVAL;
+
+ /* get the perag structure and ensure that it's inode capable */
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
+ agino = XFS_INO_TO_AGINO(mp, ino);
+
+again:
+ error = 0;
+ rcu_read_lock();
+ ip = radix_tree_lookup(&pag->pag_ici_root, agino);
+
+ if (ip) {
+ error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
+ if (error)
+ goto out_error_or_again;
+ } else {
+ rcu_read_unlock();
+ XFS_STATS_INC(xs_ig_missed);
+
+ error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
+ flags, lock_flags);
+ if (error)
+ goto out_error_or_again;
+ }
+ xfs_perag_put(pag);
+
+ *ipp = ip;
+
+ /*
+ * If we have a real type for an on-disk inode, we can set ops(&unlock)
+ * now. If it's a new inode being created, xfs_ialloc will handle it.
+ */
+ if (xfs_iflags_test(ip, XFS_INEW) && ip->i_d.di_mode != 0)
+ xfs_setup_inode(ip);
+ return 0;
+
+out_error_or_again:
+ if (error == EAGAIN) {
+ delay(1);
+ goto again;
+ }
+ xfs_perag_put(pag);
+ return error;
+}
+
/*
* The inode lookup is done in batches to keep the amount of lock traffic and
* radix tree lookups to a minimum. The batch size is a trade off between
xfs_reclaim_work_queue(mp);
}
-void
+static void
__xfs_inode_set_reclaim_tag(
struct xfs_perag *pag,
struct xfs_inode *ip)
}
}
-void
+STATIC void
__xfs_inode_clear_reclaim_tag(
xfs_mount_t *mp,
xfs_perag_t *pag,
* then a shut down during filesystem unmount reclaim walk leak all the
* unreclaimed inodes.
*/
-int
+STATIC int
xfs_reclaim_inodes_ag(
struct xfs_mount *mp,
int flags,
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