1 files changed, 214 insertions, 4 deletions

diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h
index 5166322807e7..191b22b9a35b 100644
--- a/fs/xfs/libxfs/xfs_ag.h
+++ b/fs/xfs/libxfs/xfs_ag.h
@@ -9,6 +9,215 @@
 
 struct xfs_mount;
 struct xfs_trans;
+struct xfs_perag;
+
+/*
+ * Per-ag infrastructure
+ */
+
+/* per-AG block reservation data structures*/
+struct xfs_ag_resv {
+	/* number of blocks originally reserved here */
+	xfs_extlen_t			ar_orig_reserved;
+	/* number of blocks reserved here */
+	xfs_extlen_t			ar_reserved;
+	/* number of blocks originally asked for */
+	xfs_extlen_t			ar_asked;
+};
+
+/*
+ * Per-ag incore structure, copies of information in agf and agi, to improve the
+ * performance of allocation group selection.
+ */
+struct xfs_perag {
+	struct xfs_mount *pag_mount;	/* owner filesystem */
+	xfs_agnumber_t	pag_agno;	/* AG this structure belongs to */
+	atomic_t	pag_ref;	/* perag reference count */
+	char		pagf_init;	/* this agf's entry is initialized */
+	char		pagi_init;	/* this agi's entry is initialized */
+	char		pagf_metadata;	/* the agf is preferred to be metadata */
+	char		pagi_inodeok;	/* The agi is ok for inodes */
+	uint8_t		pagf_levels[XFS_BTNUM_AGF];
+					/* # of levels in bno & cnt btree */
+	bool		pagf_agflreset; /* agfl requires reset before use */
+	uint32_t	pagf_flcount;	/* count of blocks in freelist */
+	xfs_extlen_t	pagf_freeblks;	/* total free blocks */
+	xfs_extlen_t	pagf_longest;	/* longest free space */
+	uint32_t	pagf_btreeblks;	/* # of blocks held in AGF btrees */
+	xfs_agino_t	pagi_freecount;	/* number of free inodes */
+	xfs_agino_t	pagi_count;	/* number of allocated inodes */
+
+	/*
+	 * Inode allocation search lookup optimisation.
+	 * If the pagino matches, the search for new inodes
+	 * doesn't need to search the near ones again straight away
+	 */
+	xfs_agino_t	pagl_pagino;
+	xfs_agino_t	pagl_leftrec;
+	xfs_agino_t	pagl_rightrec;
+
+	int		pagb_count;	/* pagb slots in use */
+	uint8_t		pagf_refcount_level; /* recount btree height */
+
+	/* Blocks reserved for all kinds of metadata. */
+	struct xfs_ag_resv	pag_meta_resv;
+	/* Blocks reserved for the reverse mapping btree. */
+	struct xfs_ag_resv	pag_rmapbt_resv;
+
+	/* for rcu-safe freeing */
+	struct rcu_head	rcu_head;
+
+	/* Precalculated geometry info */
+	xfs_agblock_t		block_count;
+	xfs_agblock_t		min_block;
+	xfs_agino_t		agino_min;
+	xfs_agino_t		agino_max;
+
+#ifdef __KERNEL__
+	/* -- kernel only structures below this line -- */
+
+	/*
+	 * Bitsets of per-ag metadata that have been checked and/or are sick.
+	 * Callers should hold pag_state_lock before accessing this field.
+	 */
+	uint16_t	pag_checked;
+	uint16_t	pag_sick;
+	spinlock_t	pag_state_lock;
+
+	spinlock_t	pagb_lock;	/* lock for pagb_tree */
+	struct rb_root	pagb_tree;	/* ordered tree of busy extents */
+	unsigned int	pagb_gen;	/* generation count for pagb_tree */
+	wait_queue_head_t pagb_wait;	/* woken when pagb_gen changes */
+
+	atomic_t        pagf_fstrms;    /* # of filestreams active in this AG */
+
+	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 */
+	unsigned long	pag_ici_reclaim_cursor;	/* reclaim restart point */
+
+	/* buffer cache index */
+	spinlock_t	pag_buf_lock;	/* lock for pag_buf_hash */
+	struct rhashtable pag_buf_hash;
+
+	/* background prealloc block trimming */
+	struct delayed_work	pag_blockgc_work;
+
+#endif /* __KERNEL__ */
+};
+
+int xfs_initialize_perag(struct xfs_mount *mp, xfs_agnumber_t agcount,
+			xfs_rfsblock_t dcount, xfs_agnumber_t *maxagi);
+int xfs_initialize_perag_data(struct xfs_mount *mp, xfs_agnumber_t agno);
+void xfs_free_perag(struct xfs_mount *mp);
+
+struct xfs_perag *xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno);
+struct xfs_perag *xfs_perag_get_tag(struct xfs_mount *mp, xfs_agnumber_t agno,
+		unsigned int tag);
+void xfs_perag_put(struct xfs_perag *pag);
+
+/*
+ * Per-ag geometry infomation and validation
+ */
+xfs_agblock_t xfs_ag_block_count(struct xfs_mount *mp, xfs_agnumber_t agno);
+void xfs_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,
+		xfs_agino_t *first, xfs_agino_t *last);
+
+static inline bool
+xfs_verify_agbno(struct xfs_perag *pag, xfs_agblock_t agbno)
+{
+	if (agbno >= pag->block_count)
+		return false;
+	if (agbno <= pag->min_block)
+		return false;
+	return true;
+}
+
+static inline bool
+xfs_verify_agbext(
+	struct xfs_perag	*pag,
+	xfs_agblock_t		agbno,
+	xfs_agblock_t		len)
+{
+	if (agbno + len <= agbno)
+		return false;
+
+	if (!xfs_verify_agbno(pag, agbno))
+		return false;
+
+	return xfs_verify_agbno(pag, agbno + len - 1);
+}
+
+/*
+ * Verify that an AG inode number pointer neither points outside the AG
+ * nor points at static metadata.
+ */
+static inline bool
+xfs_verify_agino(struct xfs_perag *pag, xfs_agino_t agino)
+{
+	if (agino < pag->agino_min)
+		return false;
+	if (agino > pag->agino_max)
+		return false;
+	return true;
+}
+
+/*
+ * Verify that an AG inode number pointer neither points outside the AG
+ * nor points at static metadata, or is NULLAGINO.
+ */
+static inline bool
+xfs_verify_agino_or_null(struct xfs_perag *pag, xfs_agino_t agino)
+{
+	if (agino == NULLAGINO)
+		return true;
+	return xfs_verify_agino(pag, agino);
+}
+
+static inline bool
+xfs_ag_contains_log(struct xfs_mount *mp, xfs_agnumber_t agno)
+{
+	return mp->m_sb.sb_logstart > 0 &&
+	       agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
+}
+
+/*
+ * Perag iteration APIs
+ */
+static inline struct xfs_perag *
+xfs_perag_next(
+	struct xfs_perag	*pag,
+	xfs_agnumber_t		*agno,
+	xfs_agnumber_t		end_agno)
+{
+	struct xfs_mount	*mp = pag->pag_mount;
+
+	*agno = pag->pag_agno + 1;
+	xfs_perag_put(pag);
+	if (*agno > end_agno)
+		return NULL;
+	return xfs_perag_get(mp, *agno);
+}
+
+#define for_each_perag_range(mp, agno, end_agno, pag) \
+	for ((pag) = xfs_perag_get((mp), (agno)); \
+		(pag) != NULL; \
+		(pag) = xfs_perag_next((pag), &(agno), (end_agno)))
+
+#define for_each_perag_from(mp, agno, pag) \
+	for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount - 1, (pag))
+
+
+#define for_each_perag(mp, agno, pag) \
+	(agno) = 0; \
+	for_each_perag_from((mp), (agno), (pag))
+
+#define for_each_perag_tag(mp, agno, pag, tag) \
+	for ((agno) = 0, (pag) = xfs_perag_get_tag((mp), 0, (tag)); \
+		(pag) != NULL; \
+		(agno) = (pag)->pag_agno + 1, \
+		xfs_perag_put(pag), \
+		(pag) = xfs_perag_get_tag((mp), (agno), (tag)))
 
 struct aghdr_init_data {
 	/* per ag data */
@@ -24,9 +233,10 @@ struct aghdr_init_data {
 };
 
 int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
-int xfs_ag_extend_space(struct xfs_mount *mp, struct xfs_trans *tp,
-			struct aghdr_init_data *id, xfs_extlen_t len);
-int xfs_ag_get_geometry(struct xfs_mount *mp, xfs_agnumber_t agno,
-			struct xfs_ag_geometry *ageo);
+int xfs_ag_shrink_space(struct xfs_perag *pag, struct xfs_trans **tpp,
+			xfs_extlen_t delta);
+int xfs_ag_extend_space(struct xfs_perag *pag, struct xfs_trans *tp,
+			xfs_extlen_t len);
+int xfs_ag_get_geometry(struct xfs_perag *pag, struct xfs_ag_geometry *ageo);
 
 #endif /* __LIBXFS_AG_H */