hc
2024-12-19 9370bb92b2d16684ee45cf24e879c93c509162da
kernel/fs/ext4/extents_status.h
....@@ -70,12 +70,57 @@
7070
7171 struct ext4_es_stats {
7272 unsigned long es_stats_shrunk;
73
- unsigned long es_stats_cache_hits;
74
- unsigned long es_stats_cache_misses;
73
+ struct percpu_counter es_stats_cache_hits;
74
+ struct percpu_counter es_stats_cache_misses;
7575 u64 es_stats_scan_time;
7676 u64 es_stats_max_scan_time;
7777 struct percpu_counter es_stats_all_cnt;
7878 struct percpu_counter es_stats_shk_cnt;
79
+};
80
+
81
+/*
82
+ * Pending cluster reservations for bigalloc file systems
83
+ *
84
+ * A cluster with a pending reservation is a logical cluster shared by at
85
+ * least one extent in the extents status tree with delayed and unwritten
86
+ * status and at least one other written or unwritten extent. The
87
+ * reservation is said to be pending because a cluster reservation would
88
+ * have to be taken in the event all blocks in the cluster shared with
89
+ * written or unwritten extents were deleted while the delayed and
90
+ * unwritten blocks remained.
91
+ *
92
+ * The set of pending cluster reservations is an auxiliary data structure
93
+ * used with the extents status tree to implement reserved cluster/block
94
+ * accounting for bigalloc file systems. The set is kept in memory and
95
+ * records all pending cluster reservations.
96
+ *
97
+ * Its primary function is to avoid the need to read extents from the
98
+ * disk when invalidating pages as a result of a truncate, punch hole, or
99
+ * collapse range operation. Page invalidation requires a decrease in the
100
+ * reserved cluster count if it results in the removal of all delayed
101
+ * and unwritten extents (blocks) from a cluster that is not shared with a
102
+ * written or unwritten extent, and no decrease otherwise. Determining
103
+ * whether the cluster is shared can be done by searching for a pending
104
+ * reservation on it.
105
+ *
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+ * Secondarily, it provides a potentially faster method for determining
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+ * whether the reserved cluster count should be increased when a physical
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+ * cluster is deallocated as a result of a truncate, punch hole, or
109
+ * collapse range operation. The necessary information is also present
110
+ * in the extents status tree, but might be more rapidly accessed in
111
+ * the pending reservation set in many cases due to smaller size.
112
+ *
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+ * The pending cluster reservation set is implemented as a red-black tree
114
+ * with the goal of minimizing per page search time overhead.
115
+ */
116
+
117
+struct pending_reservation {
118
+ struct rb_node rb_node;
119
+ ext4_lblk_t lclu;
120
+};
121
+
122
+struct ext4_pending_tree {
123
+ struct rb_root root;
79124 };
80125
81126 extern int __init ext4_init_es(void);
....@@ -90,11 +135,19 @@
90135 unsigned int status);
91136 extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
92137 ext4_lblk_t len);
93
-extern void ext4_es_find_delayed_extent_range(struct inode *inode,
94
- ext4_lblk_t lblk, ext4_lblk_t end,
95
- struct extent_status *es);
138
+extern void ext4_es_find_extent_range(struct inode *inode,
139
+ int (*match_fn)(struct extent_status *es),
140
+ ext4_lblk_t lblk, ext4_lblk_t end,
141
+ struct extent_status *es);
96142 extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
143
+ ext4_lblk_t *next_lblk,
97144 struct extent_status *es);
145
+extern bool ext4_es_scan_range(struct inode *inode,
146
+ int (*matching_fn)(struct extent_status *es),
147
+ ext4_lblk_t lblk, ext4_lblk_t end);
148
+extern bool ext4_es_scan_clu(struct inode *inode,
149
+ int (*matching_fn)(struct extent_status *es),
150
+ ext4_lblk_t lblk);
98151
99152 static inline unsigned int ext4_es_status(struct extent_status *es)
100153 {
....@@ -126,6 +179,16 @@
126179 return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
127180 }
128181
182
+static inline int ext4_es_is_mapped(struct extent_status *es)
183
+{
184
+ return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
185
+}
186
+
187
+static inline int ext4_es_is_delonly(struct extent_status *es)
188
+{
189
+ return (ext4_es_is_delayed(es) && !ext4_es_is_unwritten(es));
190
+}
191
+
129192 static inline void ext4_es_set_referenced(struct extent_status *es)
130193 {
131194 es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
....@@ -144,6 +207,12 @@
144207 static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
145208 {
146209 return es->es_pblk & ~ES_MASK;
210
+}
211
+
212
+static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es)
213
+{
214
+ ext4_fsblk_t pblock = ext4_es_pblock(es);
215
+ return pblock == ~ES_MASK ? 0 : pblock;
147216 }
148217
149218 static inline void ext4_es_store_pblock(struct extent_status *es,
....@@ -175,4 +244,15 @@
175244
176245 extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
177246
247
+extern int __init ext4_init_pending(void);
248
+extern void ext4_exit_pending(void);
249
+extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
250
+extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
251
+extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
252
+extern int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
253
+ bool allocated);
254
+extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
255
+ ext4_lblk_t len);
256
+extern void ext4_clear_inode_es(struct inode *inode);
257
+
178258 #endif /* _EXT4_EXTENTS_STATUS_H */