xfs: use generic percpu counters for free inode counter
XFS has hand-rolled per-cpu counters for the superblock since before
there was any generic implementation. The free inode counter is not
used for any limit enforcement - the per-AG free inode counters are
used during allocation to determine if there are inode available for
allocation.
Hence we don't need any of the complexity of the hand-rolled
counters and we can simply replace them with generic per-cpu
counters similar to the inode counter.
This version introduces a xfs_mod_ifree() helper function from
Christoph Hellwig.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 702ea6a..650e8f1 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1114,6 +1114,20 @@
return 0;
}
+
+int
+xfs_mod_ifree(
+ struct xfs_mount *mp,
+ int64_t delta)
+{
+ percpu_counter_add(&mp->m_ifree, delta);
+ if (percpu_counter_compare(&mp->m_ifree, 0) < 0) {
+ ASSERT(0);
+ percpu_counter_add(&mp->m_ifree, -delta);
+ return -EINVAL;
+ }
+ return 0;
+}
/*
* xfs_mod_incore_sb_unlocked() is a utility routine commonly used to apply
* a delta to a specified field in the in-core superblock. Simply
@@ -1142,17 +1156,9 @@
*/
switch (field) {
case XFS_SBS_ICOUNT:
- ASSERT(0);
- return -ENOSPC;
case XFS_SBS_IFREE:
- lcounter = (long long)mp->m_sb.sb_ifree;
- lcounter += delta;
- if (lcounter < 0) {
- ASSERT(0);
- return -EINVAL;
- }
- mp->m_sb.sb_ifree = lcounter;
- return 0;
+ ASSERT(0);
+ return -EINVAL;
case XFS_SBS_FDBLOCKS:
lcounter = (long long)
mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
@@ -1502,7 +1508,6 @@
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
xfs_icsb_lock(mp);
- xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
xfs_icsb_unlock(mp);
break;
@@ -1513,15 +1518,12 @@
* re-enable the counters. */
xfs_icsb_lock(mp);
spin_lock(&mp->m_sb_lock);
- xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
- mp->m_sb.sb_ifree += cntp->icsb_ifree;
mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
- xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
spin_unlock(&mp->m_sb_lock);
xfs_icsb_unlock(mp);
@@ -1544,10 +1546,14 @@
if (error)
return error;
+ error = percpu_counter_init(&mp->m_ifree, 0, GFP_KERNEL);
+ if (error)
+ goto free_icount;
+
mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
if (!mp->m_sb_cnts) {
- percpu_counter_destroy(&mp->m_icount);
- return -ENOMEM;
+ error = -ENOMEM;
+ goto free_ifree;
}
for_each_online_cpu(i) {
@@ -1570,6 +1576,12 @@
#endif /* CONFIG_HOTPLUG_CPU */
return 0;
+
+free_ifree:
+ percpu_counter_destroy(&mp->m_ifree);
+free_icount:
+ percpu_counter_destroy(&mp->m_icount);
+ return error;
}
void
@@ -1577,6 +1589,7 @@
xfs_mount_t *mp)
{
percpu_counter_set(&mp->m_icount, mp->m_sb.sb_icount);
+ percpu_counter_set(&mp->m_ifree, mp->m_sb.sb_ifree);
xfs_icsb_lock(mp);
/*
@@ -1584,7 +1597,6 @@
* initial balance kicks us off correctly
*/
mp->m_icsb_counters = -1;
- xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
xfs_icsb_unlock(mp);
}
@@ -1599,6 +1611,7 @@
}
percpu_counter_destroy(&mp->m_icount);
+ percpu_counter_destroy(&mp->m_ifree);
mutex_destroy(&mp->m_icsb_mutex);
}
@@ -1662,7 +1675,6 @@
for_each_online_cpu(i) {
cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
- cnt->icsb_ifree += cntp->icsb_ifree;
cnt->icsb_fdblocks += cntp->icsb_fdblocks;
}
@@ -1675,7 +1687,7 @@
xfs_mount_t *mp,
xfs_sb_field_t field)
{
- ASSERT((field >= XFS_SBS_IFREE) && (field <= XFS_SBS_FDBLOCKS));
+ ASSERT(field == XFS_SBS_FDBLOCKS);
return test_bit(field, &mp->m_icsb_counters);
}
@@ -1686,7 +1698,7 @@
{
xfs_icsb_cnts_t cnt;
- ASSERT((field >= XFS_SBS_IFREE) && (field <= XFS_SBS_FDBLOCKS));
+ ASSERT(field == XFS_SBS_FDBLOCKS);
/*
* If we are already disabled, then there is nothing to do
@@ -1705,9 +1717,6 @@
xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
switch(field) {
- case XFS_SBS_IFREE:
- mp->m_sb.sb_ifree = cnt.icsb_ifree;
- break;
case XFS_SBS_FDBLOCKS:
mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
break;
@@ -1729,15 +1738,12 @@
xfs_icsb_cnts_t *cntp;
int i;
- ASSERT((field >= XFS_SBS_IFREE) && (field <= XFS_SBS_FDBLOCKS));
+ ASSERT(field == XFS_SBS_FDBLOCKS);
xfs_icsb_lock_all_counters(mp);
for_each_online_cpu(i) {
cntp = per_cpu_ptr(mp->m_sb_cnts, i);
switch (field) {
- case XFS_SBS_IFREE:
- cntp->icsb_ifree = count + resid;
- break;
case XFS_SBS_FDBLOCKS:
cntp->icsb_fdblocks = count + resid;
break;
@@ -1760,8 +1766,6 @@
xfs_icsb_count(mp, &cnt, flags);
- if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
- mp->m_sb.sb_ifree = cnt.icsb_ifree;
if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
}
@@ -1813,12 +1817,6 @@
/* update counters - first CPU gets residual*/
switch (field) {
- case XFS_SBS_IFREE:
- count = mp->m_sb.sb_ifree;
- resid = do_div(count, weight);
- if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
- return;
- break;
case XFS_SBS_FDBLOCKS:
count = mp->m_sb.sb_fdblocks;
resid = do_div(count, weight);
@@ -1873,14 +1871,6 @@
}
switch (field) {
- case XFS_SBS_IFREE:
- lcounter = icsbp->icsb_ifree;
- lcounter += delta;
- if (unlikely(lcounter < 0))
- goto balance_counter;
- icsbp->icsb_ifree = lcounter;
- break;
-
case XFS_SBS_FDBLOCKS:
BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);