Re: [PATCH 25/28] xfs: remove unusued old inode reclaim code

Brian Foster
2019-11-06T17:21:23Z

On Fri, Nov 01, 2019 at 10:46:15AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Now that the custom AG radix tree walker has been replaced and
> removed, we don't need the radix tree tags anymore, nor the reclaim
> cursors or the locks taht protect it. Remove all remaining traces of
> these things.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

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

> fs/xfs/xfs_icache.c | 82 +--------------------------------------------
> fs/xfs/xfs_icache.h | 7 ++--
> fs/xfs/xfs_mount.c | 4 ---
> fs/xfs/xfs_mount.h | 3 --
> fs/xfs/xfs_super.c | 5 +--
> 5 files changed, 6 insertions(+), 95 deletions(-)
>
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 05dd292bfdb6..71a729e29260 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -139,83 +139,6 @@ xfs_inode_free(
> __xfs_inode_free(ip);
> }
>
> -static void
> -xfs_perag_set_reclaim_tag(
> - struct xfs_perag *pag)
> -{
> - struct xfs_mount *mp = pag->pag_mount;
> -
> - lockdep_assert_held(&pag->pag_ici_lock);
> - if (pag->pag_ici_reclaimable++)
> - return;
> -
> - /* propagate the reclaim tag up into the perag radix tree */
> - spin_lock(&mp->m_perag_lock);
> - radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno,
> - XFS_ICI_RECLAIM_TAG);
> - spin_unlock(&mp->m_perag_lock);
> -
> - trace_xfs_perag_set_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
> -}
> -
> -static void
> -xfs_perag_clear_reclaim_tag(
> - struct xfs_perag *pag)
> -{
> - struct xfs_mount *mp = pag->pag_mount;
> -
> - lockdep_assert_held(&pag->pag_ici_lock);
> - if (--pag->pag_ici_reclaimable)
> - return;
> -
> - /* clear the reclaim tag from the perag radix tree */
> - spin_lock(&mp->m_perag_lock);
> - radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno,
> - XFS_ICI_RECLAIM_TAG);
> - spin_unlock(&mp->m_perag_lock);
> - trace_xfs_perag_clear_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
> -}
> -
> -
> -/*
> - * We set the inode flag atomically with the radix tree tag.
> - * Once we get tag lookups on the radix tree, this inode flag
> - * can go away.
> - */
> -void
> -xfs_inode_set_reclaim_tag(
> - struct xfs_inode *ip)
> -{
> - struct xfs_mount *mp = ip->i_mount;
> - struct xfs_perag *pag;
> -
> - pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
> - spin_lock(&pag->pag_ici_lock);
> - spin_lock(&ip->i_flags_lock);
> -
> - radix_tree_tag_set(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino),
> - XFS_ICI_RECLAIM_TAG);
> - xfs_perag_set_reclaim_tag(pag);
> - __xfs_iflags_set(ip, XFS_IRECLAIMABLE);
> -
> - list_lru_add(&mp->m_inode_lru, &VFS_I(ip)->i_lru);
> -
> - spin_unlock(&ip->i_flags_lock);
> - spin_unlock(&pag->pag_ici_lock);
> - xfs_perag_put(pag);
> -}
> -
> -STATIC void
> -xfs_inode_clear_reclaim_tag(
> - struct xfs_perag *pag,
> - xfs_ino_t ino)
> -{
> - radix_tree_tag_clear(&pag->pag_ici_root,
> - XFS_INO_TO_AGINO(pag->pag_mount, ino),
> - XFS_ICI_RECLAIM_TAG);
> - xfs_perag_clear_reclaim_tag(pag);
> -}
> -
> static void
> xfs_inew_wait(
> struct xfs_inode *ip)
> @@ -397,18 +320,16 @@ xfs_iget_cache_hit(
> 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.
> */
> + spin_lock(&ip->i_flags_lock);
> ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
> ip->i_flags |= XFS_INEW;
> list_lru_del(&mp->m_inode_lru, &inode->i_lru);
> - xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
> inode->i_state = I_NEW;
> ip->i_sick = 0;
> ip->i_checked = 0;
> @@ -417,7 +338,6 @@ xfs_iget_cache_hit(
> init_rwsem(&inode->i_rwsem);
>
> 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)) {
> diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
> index 86e858e4a281..ec646b9e88b7 100644
> --- a/fs/xfs/xfs_icache.h
> +++ b/fs/xfs/xfs_icache.h
> @@ -25,9 +25,8 @@ struct xfs_eofblocks {
> */
> #define XFS_ICI_NO_TAG (-1) /* special flag for an untagged lookup
> in xfs_inode_ag_iterator */
> -#define XFS_ICI_RECLAIM_TAG 0 /* inode is to be reclaimed */
> -#define XFS_ICI_EOFBLOCKS_TAG 1 /* inode has blocks beyond EOF */
> -#define XFS_ICI_COWBLOCKS_TAG 2 /* inode can have cow blocks to gc */
> +#define XFS_ICI_EOFBLOCKS_TAG 0 /* inode has blocks beyond EOF */
> +#define XFS_ICI_COWBLOCKS_TAG 1 /* inode can have cow blocks to gc */
>
> /*
> * Flags for xfs_iget()
> @@ -68,8 +67,6 @@ enum lru_status xfs_inode_reclaim_isolate(struct list_head *item,
> void xfs_dispose_inodes(struct list_head *freeable);
> void xfs_reclaim_all_inodes(struct xfs_mount *mp);
>
> -void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);
> -
> void xfs_inode_set_eofblocks_tag(struct xfs_inode *ip);
> void xfs_inode_clear_eofblocks_tag(struct xfs_inode *ip);
> int xfs_icache_free_eofblocks(struct xfs_mount *, struct xfs_eofblocks *);
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 5f3fd1d8f63f..9d60a4e033a0 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -148,7 +148,6 @@ xfs_free_perag(
> ASSERT(atomic_read(&pag->pag_ref) == 0);
> xfs_iunlink_destroy(pag);
> xfs_buf_hash_destroy(pag);
> - mutex_destroy(&pag->pag_ici_reclaim_lock);
> call_rcu(&pag->rcu_head, __xfs_free_perag);
> }
> }
> @@ -200,7 +199,6 @@ xfs_initialize_perag(
> pag->pag_agno = index;
> pag->pag_mount = mp;
> spin_lock_init(&pag->pag_ici_lock);
> - mutex_init(&pag->pag_ici_reclaim_lock);
> INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
> if (xfs_buf_hash_init(pag))
> goto out_free_pag;
> @@ -242,7 +240,6 @@ xfs_initialize_perag(
> out_hash_destroy:
> xfs_buf_hash_destroy(pag);
> out_free_pag:
> - mutex_destroy(&pag->pag_ici_reclaim_lock);
> kmem_free(pag);
> out_unwind_new_pags:
> /* unwind any prior newly initialized pags */
> @@ -252,7 +249,6 @@ xfs_initialize_perag(
> break;
> xfs_buf_hash_destroy(pag);
> xfs_iunlink_destroy(pag);
> - mutex_destroy(&pag->pag_ici_reclaim_lock);
> kmem_free(pag);
> }
> return error;
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 4f153ee17e18..dea05cd867bf 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -343,9 +343,6 @@ typedef struct xfs_perag {
>
> spinlock_t pag_ici_lock; /* incore inode cache lock */
> struct radix_tree_root pag_ici_root; /* incore inode cache root */
> - int pag_ici_reclaimable; /* reclaimable inodes */
> - struct mutex pag_ici_reclaim_lock; /* serialisation point */
> - unsigned long pag_ici_reclaim_cursor; /* reclaim restart point */
>
> /* buffer cache index */
> spinlock_t pag_buf_lock; /* lock for pag_buf_hash */
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 096ae31b5436..d2200fbce139 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -916,7 +916,6 @@ xfs_fs_destroy_inode(
> spin_lock(&ip->i_flags_lock);
> ASSERT_ALWAYS(!__xfs_iflags_test(ip, XFS_IRECLAIMABLE));
> ASSERT_ALWAYS(!__xfs_iflags_test(ip, XFS_IRECLAIM));
> - spin_unlock(&ip->i_flags_lock);
>
> /*
> * We always use background reclaim here because even if the
> @@ -925,7 +924,9 @@ xfs_fs_destroy_inode(
> * this more efficiently than we can here, so simply let background
> * reclaim tear down all inodes.
> */
> - xfs_inode_set_reclaim_tag(ip);
> + __xfs_iflags_set(ip, XFS_IRECLAIMABLE);
> + list_lru_add(&mp->m_inode_lru, &VFS_I(ip)->i_lru);
> + spin_unlock(&ip->i_flags_lock);
> }
>
> static void
> --
> 2.24.0.rc0
>