// SPDX-License-Identifier: GPL-2.0 /* * Provide a pstore intermediate backend, organized into kernel memory * allocated zones that are then mapped and flushed into a single * contiguous region on a storage backend of some kind (block, mtd, etc). */ #define pr_fmt(fmt) … #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/mount.h> #include <linux/printk.h> #include <linux/fs.h> #include <linux/pstore_zone.h> #include <linux/kdev_t.h> #include <linux/device.h> #include <linux/namei.h> #include <linux/fcntl.h> #include <linux/uio.h> #include <linux/writeback.h> #include "internal.h" /** * struct psz_buffer - header of zone to flush to storage * * @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value) * @datalen: length of data in @data * @start: offset into @data where the beginning of the stored bytes begin * @data: zone data. */ struct psz_buffer { … }; /** * struct psz_kmsg_header - kmsg dump-specific header to flush to storage * * @magic: magic num for kmsg dump header * @time: kmsg dump trigger time * @compressed: whether conpressed * @counter: kmsg dump counter * @reason: the kmsg dump reason (e.g. oops, panic, etc) * @data: pointer to log data * * This is a sub-header for a kmsg dump, trailing after &psz_buffer. */ struct psz_kmsg_header { … }; /** * struct pstore_zone - single stored buffer * * @off: zone offset of storage * @type: front-end type for this zone * @name: front-end name for this zone * @buffer: pointer to data buffer managed by this zone * @oldbuf: pointer to old data buffer * @buffer_size: bytes in @buffer->data * @should_recover: whether this zone should recover from storage * @dirty: whether the data in @buffer dirty * * zone structure in memory. */ struct pstore_zone { … }; /** * struct psz_context - all about running state of pstore/zone * * @kpszs: kmsg dump storage zones * @ppsz: pmsg storage zone * @cpsz: console storage zone * @fpszs: ftrace storage zones * @kmsg_max_cnt: max count of @kpszs * @kmsg_read_cnt: counter of total read kmsg dumps * @kmsg_write_cnt: counter of total kmsg dump writes * @pmsg_read_cnt: counter of total read pmsg zone * @console_read_cnt: counter of total read console zone * @ftrace_max_cnt: max count of @fpszs * @ftrace_read_cnt: counter of max read ftrace zone * @oops_counter: counter of oops dumps * @panic_counter: counter of panic dumps * @recovered: whether finished recovering data from storage * @on_panic: whether panic is happening * @pstore_zone_info_lock: lock to @pstore_zone_info * @pstore_zone_info: information from backend * @pstore: structure for pstore */ struct psz_context { … }; static struct psz_context pstore_zone_cxt; static void psz_flush_all_dirty_zones(struct work_struct *); static DECLARE_DELAYED_WORK(psz_cleaner, psz_flush_all_dirty_zones); /** * enum psz_flush_mode - flush mode for psz_zone_write() * * @FLUSH_NONE: do not flush to storage but update data on memory * @FLUSH_PART: just flush part of data including meta data to storage * @FLUSH_META: just flush meta data of zone to storage * @FLUSH_ALL: flush all of zone */ enum psz_flush_mode { … }; static inline int buffer_datalen(struct pstore_zone *zone) { … } static inline int buffer_start(struct pstore_zone *zone) { … } static inline bool is_on_panic(void) { … } static ssize_t psz_zone_read_buffer(struct pstore_zone *zone, char *buf, size_t len, unsigned long off) { … } static int psz_zone_read_oldbuf(struct pstore_zone *zone, char *buf, size_t len, unsigned long off) { … } static int psz_zone_write(struct pstore_zone *zone, enum psz_flush_mode flush_mode, const char *buf, size_t len, unsigned long off) { … } static int psz_flush_dirty_zone(struct pstore_zone *zone) { … } static int psz_flush_dirty_zones(struct pstore_zone **zones, unsigned int cnt) { … } static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new) { … } static void psz_flush_all_dirty_zones(struct work_struct *work) { … } static int psz_kmsg_recover_data(struct psz_context *cxt) { … } static int psz_kmsg_recover_meta(struct psz_context *cxt) { … } static int psz_kmsg_recover(struct psz_context *cxt) { … } static int psz_recover_zone(struct psz_context *cxt, struct pstore_zone *zone) { … } static int psz_recover_zones(struct psz_context *cxt, struct pstore_zone **zones, unsigned int cnt) { … } /** * psz_recovery() - recover data from storage * @cxt: the context of pstore/zone * * recovery means reading data back from storage after rebooting * * Return: 0 on success, others on failure. */ static inline int psz_recovery(struct psz_context *cxt) { … } static int psz_pstore_open(struct pstore_info *psi) { … } static inline bool psz_old_ok(struct pstore_zone *zone) { … } static inline bool psz_ok(struct pstore_zone *zone) { … } static inline int psz_kmsg_erase(struct psz_context *cxt, struct pstore_zone *zone, struct pstore_record *record) { … } static inline int psz_record_erase(struct psz_context *cxt, struct pstore_zone *zone) { … } static int psz_pstore_erase(struct pstore_record *record) { … } static void psz_write_kmsg_hdr(struct pstore_zone *zone, struct pstore_record *record) { … } /* * In case zone is broken, which may occur to MTD device, we try each zones, * start at cxt->kmsg_write_cnt. */ static inline int notrace psz_kmsg_write_record(struct psz_context *cxt, struct pstore_record *record) { … } static int notrace psz_kmsg_write(struct psz_context *cxt, struct pstore_record *record) { … } static int notrace psz_record_write(struct pstore_zone *zone, struct pstore_record *record) { … } static int notrace psz_pstore_write(struct pstore_record *record) { … } static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) { … } static int psz_kmsg_read_hdr(struct pstore_zone *zone, struct pstore_record *record) { … } static ssize_t psz_kmsg_read(struct pstore_zone *zone, struct pstore_record *record) { … } /* try to combine all ftrace zones */ static ssize_t psz_ftrace_read(struct pstore_zone *zone, struct pstore_record *record) { … } static ssize_t psz_record_read(struct pstore_zone *zone, struct pstore_record *record) { … } static ssize_t psz_pstore_read(struct pstore_record *record) { … } static struct psz_context pstore_zone_cxt = …; static void psz_free_zone(struct pstore_zone **pszone) { … } static void psz_free_zones(struct pstore_zone ***pszones, unsigned int *cnt) { … } static void psz_free_all_zones(struct psz_context *cxt) { … } static struct pstore_zone *psz_init_zone(enum pstore_type_id type, loff_t *off, size_t size) { … } static struct pstore_zone **psz_init_zones(enum pstore_type_id type, loff_t *off, size_t total_size, ssize_t record_size, unsigned int *cnt) { … } static int psz_alloc_zones(struct psz_context *cxt) { … } /** * register_pstore_zone() - register to pstore/zone * * @info: back-end driver information. See &struct pstore_zone_info. * * Only one back-end at one time. * * Return: 0 on success, others on failure. */ int register_pstore_zone(struct pstore_zone_info *info) { … } EXPORT_SYMBOL_GPL(…); /** * unregister_pstore_zone() - unregister to pstore/zone * * @info: back-end driver information. See struct pstore_zone_info. */ void unregister_pstore_zone(struct pstore_zone_info *info) { … } EXPORT_SYMBOL_GPL(…); MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …;
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