Re: [PATCH 4/7] xfs: Remove icsb infrastructure

Brian Foster
2015-02-05T14:10:35Z

On Thu, Feb 05, 2015 at 07:54:06AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Now that the in-core superblock infrastructure has been replaced with
> generic per-cpu counters, we don't need it anymore. Nuke it from
> orbit so we are sure that it won't haunt us again...
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/libxfs/xfs_sb.c | 8 +-
> fs/xfs/xfs_fsops.c | 2 -
> fs/xfs/xfs_iomap.c | 1 -
> fs/xfs/xfs_linux.h | 9 -
> fs/xfs/xfs_log_recover.c | 4 +-
> fs/xfs/xfs_mount.c | 516 +----------------------------------------------
> fs/xfs/xfs_mount.h | 67 ------
> fs/xfs/xfs_super.c | 84 ++++++--
> fs/xfs/xfs_super.h | 2 +
> 9 files changed, 72 insertions(+), 621 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index 31a3e97..a270095 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -743,17 +743,15 @@ xfs_initialize_perag_data(
> btree += pag->pagf_btreeblks;
> xfs_perag_put(pag);
> }
> - /*
> - * Overwrite incore superblock counters with just-read data
> - */
> +
> + /* Overwrite incore superblock counters with just-read data */
> spin_lock(&mp->m_sb_lock);
> sbp->sb_ifree = ifree;
> sbp->sb_icount = ialloc;
> sbp->sb_fdblocks = bfree + bfreelst + btree;
> spin_unlock(&mp->m_sb_lock);
>
> - /* Fixup the per-cpu counters as well. */
> - xfs_icsb_reinit_counters(mp);
> + xfs_reinit_percpu_counters(mp);
>
> return 0;
> }
> diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> index fed97a9..a45c82b4 100644
> --- a/fs/xfs/xfs_fsops.c
> +++ b/fs/xfs/xfs_fsops.c
> @@ -630,7 +630,6 @@ xfs_fs_counts(
> xfs_mount_t *mp,
> xfs_fsop_counts_t *cnt)
> {
> - xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
> cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
> cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
> cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
> @@ -694,7 +693,6 @@ xfs_reserve_blocks(
> */
> retry:
> spin_lock(&mp->m_sb_lock);
> - xfs_icsb_sync_counters_locked(mp, 0);
>
> /*
> * If our previous reservation was larger than the current value,
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 205b948..38e633b 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -460,7 +460,6 @@ xfs_iomap_prealloc_size(
> alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN),
> alloc_blocks);
>
> - xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
> freesp = percpu_counter_read_positive(&mp->m_fdblocks);
> if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) {
> shift = 2;
> diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
> index c31d2c2..7c7842c 100644
> --- a/fs/xfs/xfs_linux.h
> +++ b/fs/xfs/xfs_linux.h
> @@ -116,15 +116,6 @@ typedef __uint64_t __psunsigned_t;
> #undef XFS_NATIVE_HOST
> #endif
>
> -/*
> - * Feature macros (disable/enable)
> - */
> -#ifdef CONFIG_SMP
> -#define HAVE_PERCPU_SB /* per cpu superblock counters are a 2.6 feature */
> -#else
> -#undef HAVE_PERCPU_SB /* per cpu superblock counters are a 2.6 feature */
> -#endif
> -
> #define irix_sgid_inherit xfs_params.sgid_inherit.val
> #define irix_symlink_mode xfs_params.symlink_mode.val
> #define xfs_panic_mask xfs_params.panic_mask.val
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index a5a945f..4f5784f 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -4463,10 +4463,10 @@ xlog_do_recover(
> xfs_sb_from_disk(sbp, XFS_BUF_TO_SBP(bp));
> ASSERT(sbp->sb_magicnum == XFS_SB_MAGIC);
> ASSERT(xfs_sb_good_version(sbp));
> + xfs_reinit_percpu_counters(log->l_mp);
> +
> xfs_buf_relse(bp);
>
> - /* We've re-read the superblock so re-initialize per-cpu counters */
> - xfs_icsb_reinit_counters(log->l_mp);
>
> xlog_recover_check_summary(log);
>
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 9e433b2..1d26200 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -43,18 +43,6 @@
> #include "xfs_sysfs.h"
>
>
> -#ifdef HAVE_PERCPU_SB
> -STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
> - int);
> -STATIC void xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
> - int);
> -STATIC void xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
> -#else
> -
> -#define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
> -#define xfs_icsb_balance_counter_locked(mp, a, b) do { } while (0)
> -#endif
> -
> static DEFINE_MUTEX(xfs_uuid_table_mutex);
> static int xfs_uuid_table_size;
> static uuid_t *xfs_uuid_table;
> @@ -347,8 +335,7 @@ reread:
> goto reread;
> }
>
> - /* Initialize per-cpu counters */
> - xfs_icsb_reinit_counters(mp);
> + xfs_reinit_percpu_counters(mp);
>
> /* no need to be quiet anymore, so reset the buf ops */
> bp->b_ops = &xfs_sb_buf_ops;
> @@ -1087,8 +1074,6 @@ xfs_log_sbcount(xfs_mount_t *mp)
> if (!xfs_fs_writable(mp, SB_FREEZE_COMPLETE))
> return 0;
>
> - xfs_icsb_sync_counters(mp, 0);
> -
> /*
> * we don't need to do this if we are updating the superblock
> * counters on every modification.
> @@ -1467,502 +1452,3 @@ xfs_dev_is_read_only(
> }
> return 0;
> }
> -
> -#ifdef HAVE_PERCPU_SB
> -/*
> - * Per-cpu incore superblock counters
> - *
> - * Simple concept, difficult implementation
> - *
> - * Basically, replace the incore superblock counters with a distributed per cpu
> - * counter for contended fields (e.g. free block count).
> - *
> - * Difficulties arise in that the incore sb is used for ENOSPC checking, and
> - * hence needs to be accurately read when we are running low on space. Hence
> - * there is a method to enable and disable the per-cpu counters based on how
> - * much "stuff" is available in them.
> - *
> - * Basically, a counter is enabled if there is enough free resource to justify
> - * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
> - * ENOSPC), then we disable the counters to synchronise all callers and
> - * re-distribute the available resources.
> - *
> - * If, once we redistributed the available resources, we still get a failure,
> - * we disable the per-cpu counter and go through the slow path.
> - *
> - * The slow path is the current xfs_mod_incore_sb() function. This means that
> - * when we disable a per-cpu counter, we need to drain its resources back to
> - * the global superblock. We do this after disabling the counter to prevent
> - * more threads from queueing up on the counter.
> - *
> - * Essentially, this means that we still need a lock in the fast path to enable
> - * synchronisation between the global counters and the per-cpu counters. This
> - * is not a problem because the lock will be local to a CPU almost all the time
> - * and have little contention except when we get to ENOSPC conditions.
> - *
> - * Basically, this lock becomes a barrier that enables us to lock out the fast
> - * path while we do things like enabling and disabling counters and
> - * synchronising the counters.
> - *
> - * Locking rules:
> - *
> - * 1. m_sb_lock before picking up per-cpu locks
> - * 2. per-cpu locks always picked up via for_each_online_cpu() order
> - * 3. accurate counter sync requires m_sb_lock + per cpu locks
> - * 4. modifying per-cpu counters requires holding per-cpu lock
> - * 5. modifying global counters requires holding m_sb_lock
> - * 6. enabling or disabling a counter requires holding the m_sb_lock
> - * and _none_ of the per-cpu locks.
> - *
> - * Disabled counters are only ever re-enabled by a balance operation
> - * that results in more free resources per CPU than a given threshold.
> - * To ensure counters don't remain disabled, they are rebalanced when
> - * the global resource goes above a higher threshold (i.e. some hysteresis
> - * is present to prevent thrashing).
> - */
> -
> -#ifdef CONFIG_HOTPLUG_CPU
> -/*
> - * hot-plug CPU notifier support.
> - *
> - * We need a notifier per filesystem as we need to be able to identify
> - * the filesystem to balance the counters out. This is achieved by
> - * having a notifier block embedded in the xfs_mount_t and doing pointer
> - * magic to get the mount pointer from the notifier block address.
> - */
> -STATIC int
> -xfs_icsb_cpu_notify(
> - struct notifier_block *nfb,
> - unsigned long action,
> - void *hcpu)
> -{
> - xfs_icsb_cnts_t *cntp;
> - xfs_mount_t *mp;
> -
> - mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
> - cntp = (xfs_icsb_cnts_t *)
> - per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
> - switch (action) {
> - case CPU_UP_PREPARE:
> - case CPU_UP_PREPARE_FROZEN:
> - /* Easy Case - initialize the area and locks, and
> - * then rebalance when online does everything else for us. */
> - memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
> - break;
> - case CPU_ONLINE:
> - case CPU_ONLINE_FROZEN:
> - xfs_icsb_lock(mp);
> - xfs_icsb_unlock(mp);
> - break;
> - case CPU_DEAD:
> - case CPU_DEAD_FROZEN:
> - /* Disable all the counters, then fold the dead cpu's
> - * count into the total on the global superblock and
> - * re-enable the counters. */
> - xfs_icsb_lock(mp);
> - spin_lock(&mp->m_sb_lock);
> -
> - memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
> -
> - spin_unlock(&mp->m_sb_lock);
> - xfs_icsb_unlock(mp);
> - break;
> - }
> -
> - return NOTIFY_OK;
> -}
> -#endif /* CONFIG_HOTPLUG_CPU */
> -
> -int
> -xfs_icsb_init_counters(
> - xfs_mount_t *mp)
> -{
> - xfs_icsb_cnts_t *cntp;
> - int error;
> - int i;
> -
> - error = percpu_counter_init(&mp->m_icount, 0, GFP_KERNEL);
> - if (error)
> - return error;
> -
> - error = percpu_counter_init(&mp->m_ifree, 0, GFP_KERNEL);
> - if (error)
> - goto free_icount;
> -
> - error = percpu_counter_init(&mp->m_fdblocks, 0, GFP_KERNEL);
> - if (error)
> - goto free_ifree;
> -
> - mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
> - if (!mp->m_sb_cnts) {
> - error = -ENOMEM;
> - goto free_fdblocks;
> - }
> -
> - for_each_online_cpu(i) {
> - cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
> - memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
> - }
> -
> - mutex_init(&mp->m_icsb_mutex);
> -
> - /*
> - * start with all counters disabled so that the
> - * initial balance kicks us off correctly
> - */
> - mp->m_icsb_counters = -1;
> -
> -#ifdef CONFIG_HOTPLUG_CPU
> - mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
> - mp->m_icsb_notifier.priority = 0;
> - register_hotcpu_notifier(&mp->m_icsb_notifier);
> -#endif /* CONFIG_HOTPLUG_CPU */
> -
> - return 0;
> -
> -free_fdblocks:
> - percpu_counter_destroy(&mp->m_fdblocks);
> -free_ifree:
> - percpu_counter_destroy(&mp->m_ifree);
> -free_icount:
> - percpu_counter_destroy(&mp->m_icount);
> - return error;
> -}
> -
> -void
> -xfs_icsb_reinit_counters(
> - 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);
> - percpu_counter_set(&mp->m_fdblocks, mp->m_sb.sb_fdblocks);
> -
> - xfs_icsb_lock(mp);
> - /*
> - * start with all counters disabled so that the
> - * initial balance kicks us off correctly
> - */
> - mp->m_icsb_counters = -1;
> - xfs_icsb_unlock(mp);
> -}
> -
> -void
> -xfs_icsb_destroy_counters(
> - xfs_mount_t *mp)
> -{
> - if (mp->m_sb_cnts) {
> - unregister_hotcpu_notifier(&mp->m_icsb_notifier);
> - free_percpu(mp->m_sb_cnts);
> - }
> -
> - percpu_counter_destroy(&mp->m_icount);
> - percpu_counter_destroy(&mp->m_ifree);
> - percpu_counter_destroy(&mp->m_fdblocks);
> -
> - mutex_destroy(&mp->m_icsb_mutex);
> -}
> -
> -STATIC void
> -xfs_icsb_lock_cntr(
> - xfs_icsb_cnts_t *icsbp)
> -{
> - while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
> - ndelay(1000);
> - }
> -}
> -
> -STATIC void
> -xfs_icsb_unlock_cntr(
> - xfs_icsb_cnts_t *icsbp)
> -{
> - clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
> -}
> -
> -
> -STATIC void
> -xfs_icsb_lock_all_counters(
> - xfs_mount_t *mp)
> -{
> - xfs_icsb_cnts_t *cntp;
> - int i;
> -
> - for_each_online_cpu(i) {
> - cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
> - xfs_icsb_lock_cntr(cntp);
> - }
> -}
> -
> -STATIC void
> -xfs_icsb_unlock_all_counters(
> - xfs_mount_t *mp)
> -{
> - xfs_icsb_cnts_t *cntp;
> - int i;
> -
> - for_each_online_cpu(i) {
> - cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
> - xfs_icsb_unlock_cntr(cntp);
> - }
> -}
> -
> -STATIC void
> -xfs_icsb_count(
> - xfs_mount_t *mp,
> - xfs_icsb_cnts_t *cnt,
> - int flags)
> -{
> - memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
> -
> - if (!(flags & XFS_ICSB_LAZY_COUNT))
> - xfs_icsb_lock_all_counters(mp);
> -
> -
> - if (!(flags & XFS_ICSB_LAZY_COUNT))
> - xfs_icsb_unlock_all_counters(mp);
> -}
> -
> -STATIC int
> -xfs_icsb_counter_disabled(
> - xfs_mount_t *mp,
> - xfs_sb_field_t field)
> -{
> - return test_bit(field, &mp->m_icsb_counters);
> -}
> -
> -STATIC void
> -xfs_icsb_disable_counter(
> - xfs_mount_t *mp,
> - xfs_sb_field_t field)
> -{
> - xfs_icsb_cnts_t cnt;
> -
> - /*
> - * If we are already disabled, then there is nothing to do
> - * here. We check before locking all the counters to avoid
> - * the expensive lock operation when being called in the
> - * slow path and the counter is already disabled. This is
> - * safe because the only time we set or clear this state is under
> - * the m_icsb_mutex.
> - */
> - if (xfs_icsb_counter_disabled(mp, field))
> - return;
> -
> - xfs_icsb_lock_all_counters(mp);
> - if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
> - /* drain back to superblock */
> -
> - xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
> - switch(field) {
> - default:
> - BUG();
> - }
> - }
> -
> - xfs_icsb_unlock_all_counters(mp);
> -}
> -
> -STATIC void
> -xfs_icsb_enable_counter(
> - xfs_mount_t *mp,
> - xfs_sb_field_t field,
> - uint64_t count,
> - uint64_t resid)
> -{
> - int i;
> -
> - xfs_icsb_lock_all_counters(mp);
> - for_each_online_cpu(i) {
> - switch (field) {
> - default:
> - BUG();
> - break;
> - }
> - resid = 0;
> - }
> - clear_bit(field, &mp->m_icsb_counters);
> - xfs_icsb_unlock_all_counters(mp);
> -}
> -
> -void
> -xfs_icsb_sync_counters_locked(
> - xfs_mount_t *mp,
> - int flags)
> -{
> - xfs_icsb_cnts_t cnt;
> -
> - xfs_icsb_count(mp, &cnt, flags);
> -}
> -
> -/*
> - * Accurate update of per-cpu counters to incore superblock
> - */
> -void
> -xfs_icsb_sync_counters(
> - xfs_mount_t *mp,
> - int flags)
> -{
> - spin_lock(&mp->m_sb_lock);
> - xfs_icsb_sync_counters_locked(mp, flags);
> - spin_unlock(&mp->m_sb_lock);
> -}
> -
> -/*
> - * Balance and enable/disable counters as necessary.
> - *
> - * Thresholds for re-enabling counters are somewhat magic. inode counts are
> - * chosen to be the same number as single on disk allocation chunk per CPU, and
> - * free blocks is something far enough zero that we aren't going thrash when we
> - * get near ENOSPC. We also need to supply a minimum we require per cpu to
> - * prevent looping endlessly when xfs_alloc_space asks for more than will
> - * be distributed to a single CPU but each CPU has enough blocks to be
> - * reenabled.
> - *
> - * Note that we can be called when counters are already disabled.
> - * xfs_icsb_disable_counter() optimises the counter locking in this case to
> - * prevent locking every per-cpu counter needlessly.
> - */
> -
> -#define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
> -#define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
> - (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
> -STATIC void
> -xfs_icsb_balance_counter_locked(
> - xfs_mount_t *mp,
> - xfs_sb_field_t field,
> - int min_per_cpu)
> -{
> - uint64_t count, resid;
> -
> - /* disable counter and sync counter */
> - xfs_icsb_disable_counter(mp, field);
> -
> - /* update counters - first CPU gets residual*/
> - switch (field) {
> - default:
> - BUG();
> - count = resid = 0; /* quiet, gcc */
> - break;
> - }
> -
> - xfs_icsb_enable_counter(mp, field, count, resid);
> -}
> -
> -STATIC void
> -xfs_icsb_balance_counter(
> - xfs_mount_t *mp,
> - xfs_sb_field_t fields,
> - int min_per_cpu)
> -{
> - spin_lock(&mp->m_sb_lock);
> - xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
> - spin_unlock(&mp->m_sb_lock);
> -}
> -
> -int
> -xfs_icsb_modify_counters(
> - xfs_mount_t *mp,
> - xfs_sb_field_t field,
> - int64_t delta,
> - int rsvd)
> -{
> - xfs_icsb_cnts_t *icsbp;
> - int ret = 0;
> -
> - might_sleep();
> -again:
> - preempt_disable();
> - icsbp = this_cpu_ptr(mp->m_sb_cnts);
> -
> - /*
> - * if the counter is disabled, go to slow path
> - */
> - if (unlikely(xfs_icsb_counter_disabled(mp, field)))
> - goto slow_path;
> - xfs_icsb_lock_cntr(icsbp);
> - if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
> - xfs_icsb_unlock_cntr(icsbp);
> - goto slow_path;
> - }
> -
> - switch (field) {
> - default:
> - BUG();
> - goto balance_counter; /* be still, gcc */
> - }
> - xfs_icsb_unlock_cntr(icsbp);
> - preempt_enable();
> - return 0;
> -
> -slow_path:
> - preempt_enable();
> -
> - /*
> - * serialise with a mutex so we don't burn lots of cpu on
> - * the superblock lock. We still need to hold the superblock
> - * lock, however, when we modify the global structures.
> - */
> - xfs_icsb_lock(mp);
> -
> - /*
> - * Now running atomically.
> - *
> - * If the counter is enabled, someone has beaten us to rebalancing.
> - * Drop the lock and try again in the fast path....
> - */
> - if (!(xfs_icsb_counter_disabled(mp, field))) {
> - xfs_icsb_unlock(mp);
> - goto again;
> - }
> -
> - /*
> - * The counter is currently disabled. Because we are
> - * running atomically here, we know a rebalance cannot
> - * be in progress. Hence we can go straight to operating
> - * on the global superblock. We do not call xfs_mod_incore_sb()
> - * here even though we need to get the m_sb_lock. Doing so
> - * will cause us to re-enter this function and deadlock.
> - * Hence we get the m_sb_lock ourselves and then call
> - * xfs_mod_incore_sb_unlocked() as the unlocked path operates
> - * directly on the global counters.
> - */
> - spin_lock(&mp->m_sb_lock);
> - ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
> - spin_unlock(&mp->m_sb_lock);
> -
> - /*
> - * Now that we've modified the global superblock, we
> - * may be able to re-enable the distributed counters
> - * (e.g. lots of space just got freed). After that
> - * we are done.
> - */
> - if (ret != -ENOSPC)
> - xfs_icsb_balance_counter(mp, field, 0);
> - xfs_icsb_unlock(mp);
> - return ret;
> -
> -balance_counter:
> - xfs_icsb_unlock_cntr(icsbp);
> - preempt_enable();
> -
> - /*
> - * We may have multiple threads here if multiple per-cpu
> - * counters run dry at the same time. This will mean we can
> - * do more balances than strictly necessary but it is not
> - * the common slowpath case.
> - */
> - xfs_icsb_lock(mp);
> -
> - /*
> - * running atomically.
> - *
> - * This will leave the counter in the correct state for future
> - * accesses. After the rebalance, we simply try again and our retry
> - * will either succeed through the fast path or slow path without
> - * another balance operation being required.
> - */
> - xfs_icsb_balance_counter(mp, field, delta);
> - xfs_icsb_unlock(mp);
> - goto again;
> -}
> -
> -#endif
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 76f5d25..ff1d1d5 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -18,8 +18,6 @@
> #ifndef __XFS_MOUNT_H__
> #define __XFS_MOUNT_H__
>
> -#ifdef __KERNEL__
> -
> struct xlog;
> struct xfs_inode;
> struct xfs_mru_cache;
> @@ -29,43 +27,6 @@ struct xfs_quotainfo;
> struct xfs_dir_ops;
> struct xfs_da_geometry;
>
> -#ifdef HAVE_PERCPU_SB
> -
> -/*
> - * Valid per-cpu incore superblock counters. Note that if you add new counters,
> - * you may need to define new counter disabled bit field descriptors as there
> - * are more possible fields in the superblock that can fit in a bitfield on a
> - * 32 bit platform. The XFS_SBS_* values for the current current counters just
> - * fit.
> - */
> -typedef struct xfs_icsb_cnts {
> - uint64_t icsb_fdblocks;
> - uint64_t icsb_ifree;
> - unsigned long icsb_flags;
> -} xfs_icsb_cnts_t;
> -
> -#define XFS_ICSB_FLAG_LOCK (1 << 0) /* counter lock bit */
> -
> -#define XFS_ICSB_LAZY_COUNT (1 << 1) /* accuracy not needed */
> -
> -extern int xfs_icsb_init_counters(struct xfs_mount *);
> -extern void xfs_icsb_reinit_counters(struct xfs_mount *);
> -extern void xfs_icsb_destroy_counters(struct xfs_mount *);
> -extern void xfs_icsb_sync_counters(struct xfs_mount *, int);
> -extern void xfs_icsb_sync_counters_locked(struct xfs_mount *, int);
> -extern int xfs_icsb_modify_counters(struct xfs_mount *, xfs_sb_field_t,
> - int64_t, int);
> -
> -#else
> -#define xfs_icsb_init_counters(mp) (0)
> -#define xfs_icsb_destroy_counters(mp) do { } while (0)
> -#define xfs_icsb_reinit_counters(mp) do { } while (0)
> -#define xfs_icsb_sync_counters(mp, flags) do { } while (0)
> -#define xfs_icsb_sync_counters_locked(mp, flags) do { } while (0)
> -#define xfs_icsb_modify_counters(mp, field, delta, rsvd) \
> - xfs_mod_incore_sb(mp, field, delta, rsvd)
> -#endif
> -
> /* dynamic preallocation free space thresholds, 5% down to 1% */
> enum {
> XFS_LOWSP_1_PCNT = 0,
> @@ -156,12 +117,6 @@ typedef struct xfs_mount {
> const struct xfs_dir_ops *m_nondir_inode_ops; /* !dir inode ops */
> uint m_chsize; /* size of next field */
> atomic_t m_active_trans; /* number trans frozen */
> -#ifdef HAVE_PERCPU_SB
> - xfs_icsb_cnts_t __percpu *m_sb_cnts; /* per-cpu superblock counters */
> - unsigned long m_icsb_counters; /* disabled per-cpu counters */
> - struct notifier_block m_icsb_notifier; /* hotplug cpu notifier */
> - struct mutex m_icsb_mutex; /* balancer sync lock */
> -#endif
> struct xfs_mru_cache *m_filestream; /* per-mount filestream data */
> struct delayed_work m_reclaim_work; /* background inode reclaim */
> struct delayed_work m_eofblocks_work; /* background eof blocks
> @@ -294,26 +249,6 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d)
> }
>
> /*
> - * Per-cpu superblock locking functions
> - */
> -#ifdef HAVE_PERCPU_SB
> -static inline void
> -xfs_icsb_lock(xfs_mount_t *mp)
> -{
> - mutex_lock(&mp->m_icsb_mutex);
> -}
> -
> -static inline void
> -xfs_icsb_unlock(xfs_mount_t *mp)
> -{
> - mutex_unlock(&mp->m_icsb_mutex);
> -}
> -#else
> -#define xfs_icsb_lock(mp)
> -#define xfs_icsb_unlock(mp)
> -#endif
> -
> -/*
> * This structure is for use by the xfs_mod_incore_sb_batch() routine.
> * xfs_growfs can specify a few fields which are more than int limit
> */
> @@ -396,6 +331,4 @@ extern int xfs_dev_is_read_only(struct xfs_mount *, char *);
>
> extern void xfs_set_low_space_thresholds(struct xfs_mount *);
>
> -#endif /* __KERNEL__ */
> -
> #endif /* __XFS_MOUNT_H__ */
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 4c6af31..af6d268 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1035,23 +1035,6 @@ xfs_free_fsname(
> kfree(mp->m_logname);
> }
>
> -STATIC void
> -xfs_fs_put_super(
> - struct super_block *sb)
> -{
> - struct xfs_mount *mp = XFS_M(sb);
> -
> - xfs_filestream_unmount(mp);
> - xfs_unmountfs(mp);
> -
> - xfs_freesb(mp);
> - xfs_icsb_destroy_counters(mp);
> - xfs_destroy_mount_workqueues(mp);
> - xfs_close_devices(mp);
> - xfs_free_fsname(mp);
> - kfree(mp);
> -}
> -
> STATIC int
> xfs_fs_sync_fs(
> struct super_block *sb,
> @@ -1100,7 +1083,6 @@ xfs_fs_statfs(
> statp->f_fsid.val[0] = (u32)id;
> statp->f_fsid.val[1] = (u32)(id >> 32);
>
> - xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
> icount = percpu_counter_sum(&mp->m_icount);
> ifree = percpu_counter_sum(&mp->m_ifree);
> fdblocks = percpu_counter_sum(&mp->m_fdblocks);
> @@ -1405,6 +1387,51 @@ xfs_finish_flags(
> return 0;
> }
>
> +static int
> +xfs_init_percpu_counters(
> + struct xfs_mount *mp)
> +{
> + int error;
> +
> + error = percpu_counter_init(&mp->m_icount, 0, GFP_KERNEL);
> + if (error)
> + return ENOMEM;
> +
> + error = percpu_counter_init(&mp->m_ifree, 0, GFP_KERNEL);
> + if (error)
> + goto free_icount;
> +
> + error = percpu_counter_init(&mp->m_fdblocks, 0, GFP_KERNEL);
> + if (error)
> + goto free_ifree;
> +
> + return 0;
> +
> +free_ifree:
> + percpu_counter_destroy(&mp->m_ifree);
> +free_icount:
> + percpu_counter_destroy(&mp->m_icount);
> + return -ENOMEM;
> +}
> +
> +void
> +xfs_reinit_percpu_counters(
> + struct xfs_mount *mp)
> +{
> + percpu_counter_set(&mp->m_icount, mp->m_sb.sb_icount);
> + percpu_counter_set(&mp->m_ifree, mp->m_sb.sb_ifree);
> + percpu_counter_set(&mp->m_fdblocks, mp->m_sb.sb_fdblocks);
> +}
> +
> +static void
> +xfs_destroy_percpu_counters(
> + struct xfs_mount *mp)
> +{
> + percpu_counter_destroy(&mp->m_icount);
> + percpu_counter_destroy(&mp->m_ifree);
> + percpu_counter_destroy(&mp->m_fdblocks);
> +}
> +
> STATIC int
> xfs_fs_fill_super(
> struct super_block *sb,
> @@ -1453,7 +1480,7 @@ xfs_fs_fill_super(
> if (error)
> goto out_close_devices;
>
> - error = xfs_icsb_init_counters(mp);
> + error = xfs_init_percpu_counters(mp);
> if (error)
> goto out_destroy_workqueues;
>
> @@ -1511,7 +1538,7 @@ xfs_fs_fill_super(
> out_free_sb:
> xfs_freesb(mp);
> out_destroy_counters:
> - xfs_icsb_destroy_counters(mp);
> + xfs_destroy_percpu_counters(mp);
> out_destroy_workqueues:
> xfs_destroy_mount_workqueues(mp);
> out_close_devices:
> @@ -1528,6 +1555,23 @@ out_destroy_workqueues:
> goto out_free_sb;
> }
>
> +STATIC void
> +xfs_fs_put_super(
> + struct super_block *sb)
> +{
> + struct xfs_mount *mp = XFS_M(sb);
> +
> + xfs_filestream_unmount(mp);
> + xfs_unmountfs(mp);
> +
> + xfs_freesb(mp);
> + xfs_destroy_percpu_counters(mp);
> + xfs_destroy_mount_workqueues(mp);
> + xfs_close_devices(mp);
> + xfs_free_fsname(mp);
> + kfree(mp);
> +}
> +
> STATIC struct dentry *
> xfs_fs_mount(
> struct file_system_type *fs_type,
> diff --git a/fs/xfs/xfs_super.h b/fs/xfs/xfs_super.h
> index 2b830c2..499058f 100644
> --- a/fs/xfs/xfs_super.h
> +++ b/fs/xfs/xfs_super.h
> @@ -72,6 +72,8 @@ extern const struct export_operations xfs_export_operations;
> extern const struct xattr_handler *xfs_xattr_handlers[];
> extern const struct quotactl_ops xfs_quotactl_operations;
>
> +extern void xfs_reinit_percpu_counters(struct xfs_mount *mp);
> +
> #define XFS_M(sb) ((struct xfs_mount *)((sb)->s_fs_info))
>
> #endif /* __XFS_SUPER_H__ */
> --
> 2.0.0
>
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