// SPDX-License-Identifier: GPL-2.0 /* * fs/ext4/extents_status.h * * Written by Yongqiang Yang <[email protected]> * Modified by * Allison Henderson <[email protected]> * Zheng Liu <[email protected]> * */ #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 … #else #define es_debug(fmt, ...) … #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 { … }; #define ES_SHIFT … #define ES_MASK … #define EXTENT_STATUS_WRITTEN … #define EXTENT_STATUS_UNWRITTEN … #define EXTENT_STATUS_DELAYED … #define EXTENT_STATUS_HOLE … #define EXTENT_STATUS_REFERENCED … #define ES_TYPE_MASK … struct ext4_sb_info; struct ext4_extent; struct extent_status { … }; struct ext4_es_tree { … }; struct ext4_es_stats { … }; /* * 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 ext4_pending_tree { … }; 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 void 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 void 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) { … } static inline unsigned int ext4_es_type(struct extent_status *es) { … } static inline int ext4_es_is_written(struct extent_status *es) { … } static inline int ext4_es_is_unwritten(struct extent_status *es) { … } static inline int ext4_es_is_delayed(struct extent_status *es) { … } static inline int ext4_es_is_hole(struct extent_status *es) { … } static inline int ext4_es_is_mapped(struct extent_status *es) { … } static inline int ext4_es_is_delonly(struct extent_status *es) { … } static inline void ext4_es_set_referenced(struct extent_status *es) { … } static inline void ext4_es_clear_referenced(struct extent_status *es) { … } static inline int ext4_es_is_referenced(struct extent_status *es) { … } static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es) { … } static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es) { … } static inline void ext4_es_store_pblock(struct extent_status *es, ext4_fsblk_t pb) { … } static inline void ext4_es_store_status(struct extent_status *es, unsigned int status) { … } static inline void ext4_es_store_pblock_status(struct extent_status *es, ext4_fsblk_t pb, unsigned int status) { … } 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 void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len, bool lclu_allocated, bool end_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 */
Codebase Browser
linux