1 files changed, 258 insertions, 0 deletions
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
new file mode 100644
index 000000000..4ec30a798
--- /dev/null
+++ b/fs/ext4/extents_status.h
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  fs/ext4/extents_status.h
+ *
+ * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
+ * Modified by
+ *	Allison Henderson <achender@linux.vnet.ibm.com>
+ *	Zheng Liu <wenqing.lz@taobao.com>
+ *
+ */
+
+#ifndef _EXT4_EXTENTS_STATUS_H
+#define _EXT4_EXTENTS_STATUS_H
+
+/*
+ * Turn on ES_DEBUG__ to get lots of info about extent status operations.
+ */
+#ifdef ES_DEBUG__
+#define es_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
+#else
+#define es_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/*
+ * With ES_AGGRESSIVE_TEST defined, the result of es caching will be
+ * checked with old map_block's result.
+ */
+#define ES_AGGRESSIVE_TEST__
+
+/*
+ * These flags live in the high bits of extent_status.es_pblk
+ */
+enum {
+	ES_WRITTEN_B,
+	ES_UNWRITTEN_B,
+	ES_DELAYED_B,
+	ES_HOLE_B,
+	ES_REFERENCED_B,
+	ES_FLAGS
+};
+
+#define ES_SHIFT (sizeof(ext4_fsblk_t)*8 - ES_FLAGS)
+#define ES_MASK (~((ext4_fsblk_t)0) << ES_SHIFT)
+
+#define EXTENT_STATUS_WRITTEN	(1 << ES_WRITTEN_B)
+#define EXTENT_STATUS_UNWRITTEN (1 << ES_UNWRITTEN_B)
+#define EXTENT_STATUS_DELAYED	(1 << ES_DELAYED_B)
+#define EXTENT_STATUS_HOLE	(1 << ES_HOLE_B)
+#define EXTENT_STATUS_REFERENCED	(1 << ES_REFERENCED_B)
+
+#define ES_TYPE_MASK	((ext4_fsblk_t)(EXTENT_STATUS_WRITTEN | \
+			  EXTENT_STATUS_UNWRITTEN | \
+			  EXTENT_STATUS_DELAYED | \
+			  EXTENT_STATUS_HOLE) << ES_SHIFT)
+
+struct ext4_sb_info;
+struct ext4_extent;
+
+struct extent_status {
+	struct rb_node rb_node;
+	ext4_lblk_t es_lblk;	/* first logical block extent covers */
+	ext4_lblk_t es_len;	/* length of extent in block */
+	ext4_fsblk_t es_pblk;	/* first physical block */
+};
+
+struct ext4_es_tree {
+	struct rb_root root;
+	struct extent_status *cache_es;	/* recently accessed extent */
+};
+
+struct ext4_es_stats {
+	unsigned long es_stats_shrunk;
+	struct percpu_counter es_stats_cache_hits;
+	struct percpu_counter es_stats_cache_misses;
+	u64 es_stats_scan_time;
+	u64 es_stats_max_scan_time;
+	struct percpu_counter es_stats_all_cnt;
+	struct percpu_counter es_stats_shk_cnt;
+};
+
+/*
+ * Pending cluster reservations for bigalloc file systems
+ *
+ * A cluster with a pending reservation is a logical cluster shared by at
+ * least one extent in the extents status tree with delayed and unwritten
+ * status and at least one other written or unwritten extent.  The
+ * reservation is said to be pending because a cluster reservation would
+ * have to be taken in the event all blocks in the cluster shared with
+ * written or unwritten extents were deleted while the delayed and
+ * unwritten blocks remained.
+ *
+ * The set of pending cluster reservations is an auxiliary data structure
+ * used with the extents status tree to implement reserved cluster/block
+ * accounting for bigalloc file systems.  The set is kept in memory and
+ * records all pending cluster reservations.
+ *
+ * Its primary function is to avoid the need to read extents from the
+ * disk when invalidating pages as a result of a truncate, punch hole, or
+ * collapse range operation.  Page invalidation requires a decrease in the
+ * reserved cluster count if it results in the removal of all delayed
+ * and unwritten extents (blocks) from a cluster that is not shared with a
+ * written or unwritten extent, and no decrease otherwise.  Determining
+ * whether the cluster is shared can be done by searching for a pending
+ * reservation on it.
+ *
+ * Secondarily, it provides a potentially faster method for determining
+ * whether the reserved cluster count should be increased when a physical
+ * cluster is deallocated as a result of a truncate, punch hole, or
+ * collapse range operation.  The necessary information is also present
+ * in the extents status tree, but might be more rapidly accessed in
+ * the pending reservation set in many cases due to smaller size.
+ *
+ * The pending cluster reservation set is implemented as a red-black tree
+ * with the goal of minimizing per page search time overhead.
+ */
+
+struct pending_reservation {
+	struct rb_node rb_node;
+	ext4_lblk_t lclu;
+};
+
+struct ext4_pending_tree {
+	struct rb_root root;
+};
+
+extern int __init ext4_init_es(void);
+extern void ext4_exit_es(void);
+extern void ext4_es_init_tree(struct ext4_es_tree *tree);
+
+extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
+				 ext4_lblk_t len, ext4_fsblk_t pblk,
+				 unsigned int status);
+extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
+				 ext4_lblk_t len, ext4_fsblk_t pblk,
+				 unsigned int status);
+extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
+				 ext4_lblk_t len);
+extern void ext4_es_find_extent_range(struct inode *inode,
+				      int (*match_fn)(struct extent_status *es),
+				      ext4_lblk_t lblk, ext4_lblk_t end,
+				      struct extent_status *es);
+extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
+				 ext4_lblk_t *next_lblk,
+				 struct extent_status *es);
+extern bool ext4_es_scan_range(struct inode *inode,
+			       int (*matching_fn)(struct extent_status *es),
+			       ext4_lblk_t lblk, ext4_lblk_t end);
+extern bool ext4_es_scan_clu(struct inode *inode,
+			     int (*matching_fn)(struct extent_status *es),
+			     ext4_lblk_t lblk);
+
+static inline unsigned int ext4_es_status(struct extent_status *es)
+{
+	return es->es_pblk >> ES_SHIFT;
+}
+
+static inline unsigned int ext4_es_type(struct extent_status *es)
+{
+	return (es->es_pblk & ES_TYPE_MASK) >> ES_SHIFT;
+}
+
+static inline int ext4_es_is_written(struct extent_status *es)
+{
+	return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0;
+}
+
+static inline int ext4_es_is_unwritten(struct extent_status *es)
+{
+	return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0;
+}
+
+static inline int ext4_es_is_delayed(struct extent_status *es)
+{
+	return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0;
+}
+
+static inline int ext4_es_is_hole(struct extent_status *es)
+{
+	return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
+}
+
+static inline int ext4_es_is_mapped(struct extent_status *es)
+{
+	return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
+}
+
+static inline int ext4_es_is_delonly(struct extent_status *es)
+{
+	return (ext4_es_is_delayed(es) && !ext4_es_is_unwritten(es));
+}
+
+static inline void ext4_es_set_referenced(struct extent_status *es)
+{
+	es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
+}
+
+static inline void ext4_es_clear_referenced(struct extent_status *es)
+{
+	es->es_pblk &= ~(((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT);
+}
+
+static inline int ext4_es_is_referenced(struct extent_status *es)
+{
+	return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0;
+}
+
+static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
+{
+	return es->es_pblk & ~ES_MASK;
+}
+
+static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es)
+{
+	ext4_fsblk_t pblock = ext4_es_pblock(es);
+	return pblock == ~ES_MASK ? 0 : pblock;
+}
+
+static inline void ext4_es_store_pblock(struct extent_status *es,
+					ext4_fsblk_t pb)
+{
+	ext4_fsblk_t block;
+
+	block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK);
+	es->es_pblk = block;
+}
+
+static inline void ext4_es_store_status(struct extent_status *es,
+					unsigned int status)
+{
+	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
+		      (es->es_pblk & ~ES_MASK);
+}
+
+static inline void ext4_es_store_pblock_status(struct extent_status *es,
+					       ext4_fsblk_t pb,
+					       unsigned int status)
+{
+	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
+		      (pb & ~ES_MASK);
+}
+
+extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
+extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
+
+extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
+
+extern int __init ext4_init_pending(void);
+extern void ext4_exit_pending(void);
+extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
+extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
+extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
+extern int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
+					bool allocated);
+extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
+					ext4_lblk_t len);
+extern void ext4_clear_inode_es(struct inode *inode);
+
+#endif /* _EXT4_EXTENTS_STATUS_H */