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-rw-r--r--fs/ext4/extents_status.h258
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diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
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+++ b/fs/ext4/extents_status.h
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+// 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 */