return last_error;
}
+/*
+ * Select the next per-ag structure to iterate during the walk. The reclaim
+ * walk is optimised only to walk AGs with reclaimable inodes in them.
+ */
+static struct xfs_perag *
+xfs_inode_ag_iter_next_pag(
+ struct xfs_mount *mp,
+ xfs_agnumber_t *first,
+ int tag)
+{
+ struct xfs_perag *pag = NULL;
+
+ if (tag == XFS_ICI_RECLAIM_TAG) {
+ int found;
+ int ref;
+
+ spin_lock(&mp->m_perag_lock);
+ found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
+ (void **)&pag, *first, 1, tag);
+ if (found <= 0) {
+ spin_unlock(&mp->m_perag_lock);
+ return NULL;
+ }
+ *first = pag->pag_agno + 1;
+ /* open coded pag reference increment */
+ ref = atomic_inc_return(&pag->pag_ref);
+ spin_unlock(&mp->m_perag_lock);
+ trace_xfs_perag_get_reclaim(mp, pag->pag_agno, ref, _RET_IP_);
+ } else {
+ pag = xfs_perag_get(mp, *first);
+ (*first)++;
+ }
+ return pag;
+}
+
int
xfs_inode_ag_iterator(
struct xfs_mount *mp,
int exclusive,
int *nr_to_scan)
{
+ struct xfs_perag *pag;
int error = 0;
int last_error = 0;
xfs_agnumber_t ag;
int nr;
nr = nr_to_scan ? *nr_to_scan : INT_MAX;
- for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
- struct xfs_perag *pag;
-
- pag = xfs_perag_get(mp, ag);
- if (!pag->pag_ici_init) {
- xfs_perag_put(pag);
- continue;
- }
+ ag = 0;
+ while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag, tag))) {
error = xfs_inode_ag_walk(mp, pag, execute, flags, tag,
exclusive, &nr);
xfs_perag_put(pag);
radix_tree_tag_set(&pag->pag_ici_root,
XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
XFS_ICI_RECLAIM_TAG);
+
+ if (!pag->pag_ici_reclaimable) {
+ /* propagate the reclaim tag up into the perag radix tree */
+ spin_lock(&ip->i_mount->m_perag_lock);
+ radix_tree_tag_set(&ip->i_mount->m_perag_tree,
+ XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
+ XFS_ICI_RECLAIM_TAG);
+ spin_unlock(&ip->i_mount->m_perag_lock);
+ trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
+ -1, _RET_IP_);
+ }
pag->pag_ici_reclaimable++;
}
radix_tree_tag_clear(&pag->pag_ici_root,
XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
pag->pag_ici_reclaimable--;
+ if (!pag->pag_ici_reclaimable) {
+ /* clear the reclaim tag from the perag radix tree */
+ spin_lock(&ip->i_mount->m_perag_lock);
+ radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
+ XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
+ XFS_ICI_RECLAIM_TAG);
+ spin_unlock(&ip->i_mount->m_perag_lock);
+ trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno,
+ -1, _RET_IP_);
+ }
}
/*
/*
* Shrinker infrastructure.
- *
- * This is all far more complex than it needs to be. It adds a global list of
- * mounts because the shrinkers can only call a global context. We need to make
- * the shrinkers pass a context to avoid the need for global state.
*/
-static LIST_HEAD(xfs_mount_list);
-static struct rw_semaphore xfs_mount_list_lock;
-
static int
xfs_reclaim_inode_shrink(
+ struct shrinker *shrink,
int nr_to_scan,
gfp_t gfp_mask)
{
struct xfs_mount *mp;
struct xfs_perag *pag;
xfs_agnumber_t ag;
- int reclaimable = 0;
+ int reclaimable;
+ mp = container_of(shrink, struct xfs_mount, m_inode_shrink);
if (nr_to_scan) {
if (!(gfp_mask & __GFP_FS))
return -1;
- down_read(&xfs_mount_list_lock);
- list_for_each_entry(mp, &xfs_mount_list, m_mplist) {
- xfs_inode_ag_iterator(mp, xfs_reclaim_inode, 0,
+ xfs_inode_ag_iterator(mp, xfs_reclaim_inode, 0,
XFS_ICI_RECLAIM_TAG, 1, &nr_to_scan);
- if (nr_to_scan <= 0)
- break;
- }
- up_read(&xfs_mount_list_lock);
- }
-
- down_read(&xfs_mount_list_lock);
- list_for_each_entry(mp, &xfs_mount_list, m_mplist) {
- for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
+ /* if we don't exhaust the scan, don't bother coming back */
+ if (nr_to_scan > 0)
+ return -1;
+ }
- pag = xfs_perag_get(mp, ag);
- if (!pag->pag_ici_init) {
- xfs_perag_put(pag);
- continue;
- }
- reclaimable += pag->pag_ici_reclaimable;
- xfs_perag_put(pag);
- }
+ reclaimable = 0;
+ ag = 0;
+ while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag,
+ XFS_ICI_RECLAIM_TAG))) {
+ reclaimable += pag->pag_ici_reclaimable;
+ xfs_perag_put(pag);
}
- up_read(&xfs_mount_list_lock);
return reclaimable;
}
-static struct shrinker xfs_inode_shrinker = {
- .shrink = xfs_reclaim_inode_shrink,
- .seeks = DEFAULT_SEEKS,
-};
-
-void __init
-xfs_inode_shrinker_init(void)
-{
- init_rwsem(&xfs_mount_list_lock);
- register_shrinker(&xfs_inode_shrinker);
-}
-
-void
-xfs_inode_shrinker_destroy(void)
-{
- ASSERT(list_empty(&xfs_mount_list));
- unregister_shrinker(&xfs_inode_shrinker);
-}
-
void
xfs_inode_shrinker_register(
struct xfs_mount *mp)
{
- down_write(&xfs_mount_list_lock);
- list_add_tail(&mp->m_mplist, &xfs_mount_list);
- up_write(&xfs_mount_list_lock);
+ mp->m_inode_shrink.shrink = xfs_reclaim_inode_shrink;
+ mp->m_inode_shrink.seeks = DEFAULT_SEEKS;
+ register_shrinker(&mp->m_inode_shrink);
}
void
xfs_inode_shrinker_unregister(
struct xfs_mount *mp)
{
- down_write(&xfs_mount_list_lock);
- list_del(&mp->m_mplist);
- up_write(&xfs_mount_list_lock);
+ unregister_shrinker(&mp->m_inode_shrink);
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff