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pstore/zone: Introduce common layer to manage storage zones
Implement a common set of APIs needed to support pstore storage zones, based on how ramoops is designed. This will be used by pstore/blk with the intention of migrating pstore/ram in the future. Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com> Link: https://lore.kernel.org/lkml/20200511233229.27745-2-keescook@chromium.org/ Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
WeiXiong Liao
Kees Cook
parent
acf12c5e58
commit
d26c3321fe
@ -153,3 +153,10 @@ config PSTORE_RAM
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"ramoops.ko".
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For more information, see Documentation/admin-guide/ramoops.rst.
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config PSTORE_ZONE
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tristate
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depends on PSTORE
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help
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The common layer for pstore/blk (and pstore/ram in the future)
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to manage storage in zones.
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@ -12,3 +12,6 @@ pstore-$(CONFIG_PSTORE_PMSG) += pmsg.o
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ramoops-objs += ram.o ram_core.o
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obj-$(CONFIG_PSTORE_RAM) += ramoops.o
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pstore_zone-objs += zone.o
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obj-$(CONFIG_PSTORE_ZONE) += pstore_zone.o
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985
fs/pstore/zone.c
Normal file
985
fs/pstore/zone.c
Normal file
@ -0,0 +1,985 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Provide a pstore intermediate backend, organized into kernel memory
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* allocated zones that are then mapped and flushed into a single
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* contiguous region on a storage backend of some kind (block, mtd, etc).
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/mount.h>
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#include <linux/printk.h>
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#include <linux/fs.h>
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#include <linux/pstore_zone.h>
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#include <linux/kdev_t.h>
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#include <linux/device.h>
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#include <linux/namei.h>
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#include <linux/fcntl.h>
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#include <linux/uio.h>
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#include <linux/writeback.h>
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#include "internal.h"
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/**
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* struct psz_head - header of zone to flush to storage
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*
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* @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value)
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* @datalen: length of data in @data
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* @data: zone data.
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*/
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struct psz_buffer {
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#define PSZ_SIG (0x43474244) /* DBGC */
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uint32_t sig;
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atomic_t datalen;
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uint8_t data[];
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};
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/**
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* struct psz_kmsg_header - kmsg dump-specific header to flush to storage
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*
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* @magic: magic num for kmsg dump header
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* @time: kmsg dump trigger time
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* @compressed: whether conpressed
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* @counter: kmsg dump counter
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* @reason: the kmsg dump reason (e.g. oops, panic, etc)
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* @data: pointer to log data
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*
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* This is a sub-header for a kmsg dump, trailing after &psz_buffer.
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*/
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struct psz_kmsg_header {
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#define PSTORE_KMSG_HEADER_MAGIC 0x4dfc3ae5 /* Just a random number */
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uint32_t magic;
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struct timespec64 time;
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bool compressed;
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uint32_t counter;
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enum kmsg_dump_reason reason;
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uint8_t data[];
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};
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/**
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* struct pstore_zone - single stored buffer
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*
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* @off: zone offset of storage
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* @type: front-end type for this zone
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* @name: front-end name for this zone
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* @buffer: pointer to data buffer managed by this zone
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* @oldbuf: pointer to old data buffer
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* @buffer_size: bytes in @buffer->data
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* @should_recover: whether this zone should recover from storage
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* @dirty: whether the data in @buffer dirty
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*
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* zone structure in memory.
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*/
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struct pstore_zone {
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loff_t off;
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const char *name;
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enum pstore_type_id type;
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struct psz_buffer *buffer;
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struct psz_buffer *oldbuf;
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size_t buffer_size;
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bool should_recover;
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atomic_t dirty;
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};
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/**
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* struct psz_context - all about running state of pstore/zone
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*
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* @kpszs: kmsg dump storage zones
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* @kmsg_max_cnt: max count of @kpszs
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* @kmsg_read_cnt: counter of total read kmsg dumps
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* @kmsg_write_cnt: counter of total kmsg dump writes
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* @oops_counter: counter of oops dumps
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* @panic_counter: counter of panic dumps
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* @recovered: whether finished recovering data from storage
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* @on_panic: whether panic is happening
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* @pstore_zone_info_lock: lock to @pstore_zone_info
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* @pstore_zone_info: information from backend
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* @pstore: structure for pstore
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*/
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struct psz_context {
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struct pstore_zone **kpszs;
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unsigned int kmsg_max_cnt;
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unsigned int kmsg_read_cnt;
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unsigned int kmsg_write_cnt;
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/*
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* These counters should be calculated during recovery.
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* It records the oops/panic times after crashes rather than boots.
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*/
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unsigned int oops_counter;
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unsigned int panic_counter;
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atomic_t recovered;
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atomic_t on_panic;
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/*
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* pstore_zone_info_lock protects this entire structure during calls
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* to register_pstore_zone()/unregister_pstore_zone().
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*/
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struct mutex pstore_zone_info_lock;
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struct pstore_zone_info *pstore_zone_info;
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struct pstore_info pstore;
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};
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static struct psz_context pstore_zone_cxt;
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/**
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* enum psz_flush_mode - flush mode for psz_zone_write()
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*
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* @FLUSH_NONE: do not flush to storage but update data on memory
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* @FLUSH_PART: just flush part of data including meta data to storage
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* @FLUSH_META: just flush meta data of zone to storage
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* @FLUSH_ALL: flush all of zone
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*/
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enum psz_flush_mode {
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FLUSH_NONE = 0,
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FLUSH_PART,
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FLUSH_META,
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FLUSH_ALL,
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};
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static inline int buffer_datalen(struct pstore_zone *zone)
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{
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return atomic_read(&zone->buffer->datalen);
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}
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static inline bool is_on_panic(void)
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{
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return atomic_read(&pstore_zone_cxt.on_panic);
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}
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static ssize_t psz_zone_read(struct pstore_zone *zone, char *buf,
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size_t len, unsigned long off)
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{
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if (!buf || !zone->buffer)
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return -EINVAL;
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if (off > zone->buffer_size)
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return -EINVAL;
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len = min_t(size_t, len, zone->buffer_size - off);
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memcpy(buf, zone->buffer->data + off, len);
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return len;
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}
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static int psz_zone_write(struct pstore_zone *zone,
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enum psz_flush_mode flush_mode, const char *buf,
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size_t len, unsigned long off)
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{
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struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info;
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ssize_t wcnt = 0;
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ssize_t (*writeop)(const char *buf, size_t bytes, loff_t pos);
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size_t wlen;
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if (off > zone->buffer_size)
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return -EINVAL;
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wlen = min_t(size_t, len, zone->buffer_size - off);
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if (buf && wlen) {
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memcpy(zone->buffer->data + off, buf, wlen);
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atomic_set(&zone->buffer->datalen, wlen + off);
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}
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/* avoid to damage old records */
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if (!is_on_panic() && !atomic_read(&pstore_zone_cxt.recovered))
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goto dirty;
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writeop = is_on_panic() ? info->panic_write : info->write;
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if (!writeop)
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goto dirty;
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switch (flush_mode) {
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case FLUSH_NONE:
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if (unlikely(buf && wlen))
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goto dirty;
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return 0;
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case FLUSH_PART:
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wcnt = writeop((const char *)zone->buffer->data + off, wlen,
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zone->off + sizeof(*zone->buffer) + off);
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if (wcnt != wlen)
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goto dirty;
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fallthrough;
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case FLUSH_META:
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wlen = sizeof(struct psz_buffer);
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wcnt = writeop((const char *)zone->buffer, wlen, zone->off);
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if (wcnt != wlen)
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goto dirty;
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break;
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case FLUSH_ALL:
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wlen = zone->buffer_size + sizeof(*zone->buffer);
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wcnt = writeop((const char *)zone->buffer, wlen, zone->off);
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if (wcnt != wlen)
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goto dirty;
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break;
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}
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return 0;
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dirty:
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atomic_set(&zone->dirty, true);
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return -EBUSY;
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}
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static int psz_flush_dirty_zone(struct pstore_zone *zone)
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{
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int ret;
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if (unlikely(!zone))
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return -EINVAL;
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if (unlikely(!atomic_read(&pstore_zone_cxt.recovered)))
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return -EBUSY;
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if (!atomic_xchg(&zone->dirty, false))
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return 0;
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ret = psz_zone_write(zone, FLUSH_ALL, NULL, 0, 0);
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if (ret)
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atomic_set(&zone->dirty, true);
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return ret;
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}
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static int psz_flush_dirty_zones(struct pstore_zone **zones, unsigned int cnt)
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{
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int i, ret;
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struct pstore_zone *zone;
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if (!zones)
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return -EINVAL;
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for (i = 0; i < cnt; i++) {
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zone = zones[i];
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if (!zone)
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return -EINVAL;
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ret = psz_flush_dirty_zone(zone);
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if (ret)
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return ret;
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}
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return 0;
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}
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static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new)
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{
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const char *data = (const char *)old->buffer->data;
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int ret;
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ret = psz_zone_write(new, FLUSH_ALL, data, buffer_datalen(old), 0);
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if (ret) {
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atomic_set(&new->buffer->datalen, 0);
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atomic_set(&new->dirty, false);
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return ret;
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}
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atomic_set(&old->buffer->datalen, 0);
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return 0;
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}
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static int psz_kmsg_recover_data(struct psz_context *cxt)
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{
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struct pstore_zone_info *info = cxt->pstore_zone_info;
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struct pstore_zone *zone = NULL;
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struct psz_buffer *buf;
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unsigned long i;
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ssize_t rcnt;
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if (!info->read)
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return -EINVAL;
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for (i = 0; i < cxt->kmsg_max_cnt; i++) {
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zone = cxt->kpszs[i];
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if (unlikely(!zone))
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return -EINVAL;
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if (atomic_read(&zone->dirty)) {
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unsigned int wcnt = cxt->kmsg_write_cnt;
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struct pstore_zone *new = cxt->kpszs[wcnt];
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int ret;
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ret = psz_move_zone(zone, new);
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if (ret) {
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pr_err("move zone from %lu to %d failed\n",
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i, wcnt);
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return ret;
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}
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cxt->kmsg_write_cnt = (wcnt + 1) % cxt->kmsg_max_cnt;
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}
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if (!zone->should_recover)
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continue;
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buf = zone->buffer;
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rcnt = info->read((char *)buf, zone->buffer_size + sizeof(*buf),
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zone->off);
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if (rcnt != zone->buffer_size + sizeof(*buf))
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return (int)rcnt < 0 ? (int)rcnt : -EIO;
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}
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return 0;
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}
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static int psz_kmsg_recover_meta(struct psz_context *cxt)
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{
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struct pstore_zone_info *info = cxt->pstore_zone_info;
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struct pstore_zone *zone;
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size_t rcnt, len;
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struct psz_buffer *buf;
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struct psz_kmsg_header *hdr;
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struct timespec64 time = { };
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unsigned long i;
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/*
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* Recover may on panic, we can't allocate any memory by kmalloc.
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* So, we use local array instead.
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*/
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char buffer_header[sizeof(*buf) + sizeof(*hdr)] = {0};
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if (!info->read)
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return -EINVAL;
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len = sizeof(*buf) + sizeof(*hdr);
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buf = (struct psz_buffer *)buffer_header;
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for (i = 0; i < cxt->kmsg_max_cnt; i++) {
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zone = cxt->kpszs[i];
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if (unlikely(!zone))
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return -EINVAL;
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rcnt = info->read((char *)buf, len, zone->off);
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if (rcnt != len) {
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pr_err("read %s with id %lu failed\n", zone->name, i);
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return (int)rcnt < 0 ? (int)rcnt : -EIO;
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}
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if (buf->sig != zone->buffer->sig) {
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pr_debug("no valid data in kmsg dump zone %lu\n", i);
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continue;
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}
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if (zone->buffer_size < atomic_read(&buf->datalen)) {
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pr_info("found overtop zone: %s: id %lu, off %lld, size %zu\n",
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zone->name, i, zone->off,
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zone->buffer_size);
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continue;
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}
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hdr = (struct psz_kmsg_header *)buf->data;
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if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) {
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pr_info("found invalid zone: %s: id %lu, off %lld, size %zu\n",
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zone->name, i, zone->off,
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zone->buffer_size);
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continue;
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}
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/*
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* we get the newest zone, and the next one must be the oldest
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* or unused zone, because we do write one by one like a circle.
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*/
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if (hdr->time.tv_sec >= time.tv_sec) {
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time.tv_sec = hdr->time.tv_sec;
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cxt->kmsg_write_cnt = (i + 1) % cxt->kmsg_max_cnt;
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}
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if (hdr->reason == KMSG_DUMP_OOPS)
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cxt->oops_counter =
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max(cxt->oops_counter, hdr->counter);
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else if (hdr->reason == KMSG_DUMP_PANIC)
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cxt->panic_counter =
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max(cxt->panic_counter, hdr->counter);
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if (!atomic_read(&buf->datalen)) {
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pr_debug("found erased zone: %s: id %lu, off %lld, size %zu, datalen %d\n",
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zone->name, i, zone->off,
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zone->buffer_size,
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atomic_read(&buf->datalen));
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continue;
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}
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if (!is_on_panic())
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zone->should_recover = true;
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pr_debug("found nice zone: %s: id %lu, off %lld, size %zu, datalen %d\n",
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zone->name, i, zone->off,
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zone->buffer_size, atomic_read(&buf->datalen));
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}
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return 0;
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}
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static int psz_kmsg_recover(struct psz_context *cxt)
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{
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int ret;
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if (!cxt->kpszs)
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return 0;
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ret = psz_kmsg_recover_meta(cxt);
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if (ret)
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goto recover_fail;
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ret = psz_kmsg_recover_data(cxt);
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if (ret)
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goto recover_fail;
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return 0;
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recover_fail:
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pr_debug("psz_recover_kmsg failed\n");
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return ret;
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}
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/**
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* psz_recovery() - recover data from storage
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* @cxt: the context of pstore/zone
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*
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* recovery means reading data back from storage after rebooting
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*
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* Return: 0 on success, others on failure.
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*/
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static inline int psz_recovery(struct psz_context *cxt)
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{
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int ret;
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if (atomic_read(&cxt->recovered))
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return 0;
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ret = psz_kmsg_recover(cxt);
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|
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if (unlikely(ret))
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pr_err("recover failed\n");
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else {
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pr_debug("recover end!\n");
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atomic_set(&cxt->recovered, 1);
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}
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return ret;
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}
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static int psz_pstore_open(struct pstore_info *psi)
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{
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struct psz_context *cxt = psi->data;
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cxt->kmsg_read_cnt = 0;
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return 0;
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}
|
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|
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static inline bool psz_ok(struct pstore_zone *zone)
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{
|
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if (zone && zone->buffer && buffer_datalen(zone))
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return true;
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return false;
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}
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|
||||
static inline int psz_kmsg_erase(struct psz_context *cxt,
|
||||
struct pstore_zone *zone, struct pstore_record *record)
|
||||
{
|
||||
struct psz_buffer *buffer = zone->buffer;
|
||||
struct psz_kmsg_header *hdr =
|
||||
(struct psz_kmsg_header *)buffer->data;
|
||||
|
||||
if (unlikely(!psz_ok(zone)))
|
||||
return 0;
|
||||
/* this zone is already updated, no need to erase */
|
||||
if (record->count != hdr->counter)
|
||||
return 0;
|
||||
|
||||
atomic_set(&zone->buffer->datalen, 0);
|
||||
return psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
|
||||
}
|
||||
|
||||
static int psz_pstore_erase(struct pstore_record *record)
|
||||
{
|
||||
struct psz_context *cxt = record->psi->data;
|
||||
|
||||
switch (record->type) {
|
||||
case PSTORE_TYPE_DMESG:
|
||||
if (record->id >= cxt->kmsg_max_cnt)
|
||||
return -EINVAL;
|
||||
return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record);
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
static void psz_write_kmsg_hdr(struct pstore_zone *zone,
|
||||
struct pstore_record *record)
|
||||
{
|
||||
struct psz_context *cxt = record->psi->data;
|
||||
struct psz_buffer *buffer = zone->buffer;
|
||||
struct psz_kmsg_header *hdr =
|
||||
(struct psz_kmsg_header *)buffer->data;
|
||||
|
||||
hdr->magic = PSTORE_KMSG_HEADER_MAGIC;
|
||||
hdr->compressed = record->compressed;
|
||||
hdr->time.tv_sec = record->time.tv_sec;
|
||||
hdr->time.tv_nsec = record->time.tv_nsec;
|
||||
hdr->reason = record->reason;
|
||||
if (hdr->reason == KMSG_DUMP_OOPS)
|
||||
hdr->counter = ++cxt->oops_counter;
|
||||
else if (hdr->reason == KMSG_DUMP_PANIC)
|
||||
hdr->counter = ++cxt->panic_counter;
|
||||
else
|
||||
hdr->counter = 0;
|
||||
}
|
||||
|
||||
static inline int notrace psz_kmsg_write_record(struct psz_context *cxt,
|
||||
struct pstore_record *record)
|
||||
{
|
||||
size_t size, hlen;
|
||||
struct pstore_zone *zone;
|
||||
unsigned int zonenum;
|
||||
|
||||
zonenum = cxt->kmsg_write_cnt;
|
||||
zone = cxt->kpszs[zonenum];
|
||||
if (unlikely(!zone))
|
||||
return -ENOSPC;
|
||||
cxt->kmsg_write_cnt = (zonenum + 1) % cxt->kmsg_max_cnt;
|
||||
|
||||
pr_debug("write %s to zone id %d\n", zone->name, zonenum);
|
||||
psz_write_kmsg_hdr(zone, record);
|
||||
hlen = sizeof(struct psz_kmsg_header);
|
||||
size = min_t(size_t, record->size, zone->buffer_size - hlen);
|
||||
return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen);
|
||||
}
|
||||
|
||||
static int notrace psz_kmsg_write(struct psz_context *cxt,
|
||||
struct pstore_record *record)
|
||||
{
|
||||
int ret;
|
||||
|
||||
/*
|
||||
* Explicitly only take the first part of any new crash.
|
||||
* If our buffer is larger than kmsg_bytes, this can never happen,
|
||||
* and if our buffer is smaller than kmsg_bytes, we don't want the
|
||||
* report split across multiple records.
|
||||
*/
|
||||
if (record->part != 1)
|
||||
return -ENOSPC;
|
||||
|
||||
if (!cxt->kpszs)
|
||||
return -ENOSPC;
|
||||
|
||||
ret = psz_kmsg_write_record(cxt, record);
|
||||
if (!ret) {
|
||||
pr_debug("try to flush other dirty zones\n");
|
||||
psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt);
|
||||
}
|
||||
|
||||
/* always return 0 as we had handled it on buffer */
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int notrace psz_pstore_write(struct pstore_record *record)
|
||||
{
|
||||
struct psz_context *cxt = record->psi->data;
|
||||
|
||||
if (record->type == PSTORE_TYPE_DMESG &&
|
||||
record->reason == KMSG_DUMP_PANIC)
|
||||
atomic_set(&cxt->on_panic, 1);
|
||||
|
||||
switch (record->type) {
|
||||
case PSTORE_TYPE_DMESG:
|
||||
return psz_kmsg_write(cxt, record);
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt)
|
||||
{
|
||||
struct pstore_zone *zone = NULL;
|
||||
|
||||
while (cxt->kmsg_read_cnt < cxt->kmsg_max_cnt) {
|
||||
zone = cxt->kpszs[cxt->kmsg_read_cnt++];
|
||||
if (psz_ok(zone))
|
||||
return zone;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static int psz_kmsg_read_hdr(struct pstore_zone *zone,
|
||||
struct pstore_record *record)
|
||||
{
|
||||
struct psz_buffer *buffer = zone->buffer;
|
||||
struct psz_kmsg_header *hdr =
|
||||
(struct psz_kmsg_header *)buffer->data;
|
||||
|
||||
if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC)
|
||||
return -EINVAL;
|
||||
record->compressed = hdr->compressed;
|
||||
record->time.tv_sec = hdr->time.tv_sec;
|
||||
record->time.tv_nsec = hdr->time.tv_nsec;
|
||||
record->reason = hdr->reason;
|
||||
record->count = hdr->counter;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static ssize_t psz_kmsg_read(struct pstore_zone *zone,
|
||||
struct pstore_record *record)
|
||||
{
|
||||
ssize_t size, hlen = 0;
|
||||
|
||||
size = buffer_datalen(zone);
|
||||
/* Clear and skip this kmsg dump record if it has no valid header */
|
||||
if (psz_kmsg_read_hdr(zone, record)) {
|
||||
atomic_set(&zone->buffer->datalen, 0);
|
||||
atomic_set(&zone->dirty, 0);
|
||||
return -ENOMSG;
|
||||
}
|
||||
size -= sizeof(struct psz_kmsg_header);
|
||||
|
||||
if (!record->compressed) {
|
||||
char *buf = kasprintf(GFP_KERNEL, "%s: Total %d times\n",
|
||||
kmsg_dump_reason_str(record->reason),
|
||||
record->count);
|
||||
hlen = strlen(buf);
|
||||
record->buf = krealloc(buf, hlen + size, GFP_KERNEL);
|
||||
if (!record->buf) {
|
||||
kfree(buf);
|
||||
return -ENOMEM;
|
||||
}
|
||||
} else {
|
||||
record->buf = kmalloc(size, GFP_KERNEL);
|
||||
if (!record->buf)
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
size = psz_zone_read(zone, record->buf + hlen, size,
|
||||
sizeof(struct psz_kmsg_header));
|
||||
if (unlikely(size < 0)) {
|
||||
kfree(record->buf);
|
||||
return -ENOMSG;
|
||||
}
|
||||
|
||||
return size + hlen;
|
||||
}
|
||||
|
||||
static ssize_t psz_pstore_read(struct pstore_record *record)
|
||||
{
|
||||
struct psz_context *cxt = record->psi->data;
|
||||
ssize_t (*readop)(struct pstore_zone *zone,
|
||||
struct pstore_record *record);
|
||||
struct pstore_zone *zone;
|
||||
ssize_t ret;
|
||||
|
||||
/* before read, we must recover from storage */
|
||||
ret = psz_recovery(cxt);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
next_zone:
|
||||
zone = psz_read_next_zone(cxt);
|
||||
if (!zone)
|
||||
return 0;
|
||||
|
||||
record->type = zone->type;
|
||||
switch (record->type) {
|
||||
case PSTORE_TYPE_DMESG:
|
||||
readop = psz_kmsg_read;
|
||||
record->id = cxt->kmsg_read_cnt - 1;
|
||||
break;
|
||||
default:
|
||||
goto next_zone;
|
||||
}
|
||||
|
||||
ret = readop(zone, record);
|
||||
if (ret == -ENOMSG)
|
||||
goto next_zone;
|
||||
return ret;
|
||||
}
|
||||
|
||||
static struct psz_context pstore_zone_cxt = {
|
||||
.pstore_zone_info_lock =
|
||||
__MUTEX_INITIALIZER(pstore_zone_cxt.pstore_zone_info_lock),
|
||||
.recovered = ATOMIC_INIT(0),
|
||||
.on_panic = ATOMIC_INIT(0),
|
||||
.pstore = {
|
||||
.owner = THIS_MODULE,
|
||||
.open = psz_pstore_open,
|
||||
.read = psz_pstore_read,
|
||||
.write = psz_pstore_write,
|
||||
.erase = psz_pstore_erase,
|
||||
},
|
||||
};
|
||||
|
||||
static void psz_free_zone(struct pstore_zone **pszone)
|
||||
{
|
||||
struct pstore_zone *zone = *pszone;
|
||||
|
||||
if (!zone)
|
||||
return;
|
||||
|
||||
kfree(zone->buffer);
|
||||
kfree(zone);
|
||||
*pszone = NULL;
|
||||
}
|
||||
|
||||
static void psz_free_zones(struct pstore_zone ***pszones, unsigned int *cnt)
|
||||
{
|
||||
struct pstore_zone **zones = *pszones;
|
||||
|
||||
if (!zones)
|
||||
return;
|
||||
|
||||
while (*cnt > 0) {
|
||||
(*cnt)--;
|
||||
psz_free_zone(&(zones[*cnt]));
|
||||
}
|
||||
kfree(zones);
|
||||
*pszones = NULL;
|
||||
}
|
||||
|
||||
static void psz_free_all_zones(struct psz_context *cxt)
|
||||
{
|
||||
if (cxt->kpszs)
|
||||
psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt);
|
||||
}
|
||||
|
||||
static struct pstore_zone *psz_init_zone(enum pstore_type_id type,
|
||||
loff_t *off, size_t size)
|
||||
{
|
||||
struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info;
|
||||
struct pstore_zone *zone;
|
||||
const char *name = pstore_type_to_name(type);
|
||||
|
||||
if (!size)
|
||||
return NULL;
|
||||
|
||||
if (*off + size > info->total_size) {
|
||||
pr_err("no room for %s (0x%zx@0x%llx over 0x%lx)\n",
|
||||
name, size, *off, info->total_size);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
|
||||
zone = kzalloc(sizeof(struct pstore_zone), GFP_KERNEL);
|
||||
if (!zone)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
zone->buffer = kmalloc(size, GFP_KERNEL);
|
||||
if (!zone->buffer) {
|
||||
kfree(zone);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
memset(zone->buffer, 0xFF, size);
|
||||
zone->off = *off;
|
||||
zone->name = name;
|
||||
zone->type = type;
|
||||
zone->buffer_size = size - sizeof(struct psz_buffer);
|
||||
zone->buffer->sig = type ^ PSZ_SIG;
|
||||
atomic_set(&zone->dirty, 0);
|
||||
atomic_set(&zone->buffer->datalen, 0);
|
||||
|
||||
*off += size;
|
||||
|
||||
pr_debug("pszone %s: off 0x%llx, %zu header, %zu data\n", zone->name,
|
||||
zone->off, sizeof(*zone->buffer), zone->buffer_size);
|
||||
return zone;
|
||||
}
|
||||
|
||||
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)
|
||||
{
|
||||
struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info;
|
||||
struct pstore_zone **zones, *zone;
|
||||
const char *name = pstore_type_to_name(type);
|
||||
int c, i;
|
||||
|
||||
*cnt = 0;
|
||||
if (!total_size || !record_size)
|
||||
return NULL;
|
||||
|
||||
if (*off + total_size > info->total_size) {
|
||||
pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n",
|
||||
name, total_size, *off, info->total_size);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
|
||||
c = total_size / record_size;
|
||||
zones = kcalloc(c, sizeof(*zones), GFP_KERNEL);
|
||||
if (!zones) {
|
||||
pr_err("allocate for zones %s failed\n", name);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
memset(zones, 0, c * sizeof(*zones));
|
||||
|
||||
for (i = 0; i < c; i++) {
|
||||
zone = psz_init_zone(type, off, record_size);
|
||||
if (!zone || IS_ERR(zone)) {
|
||||
pr_err("initialize zones %s failed\n", name);
|
||||
psz_free_zones(&zones, &i);
|
||||
return (void *)zone;
|
||||
}
|
||||
zones[i] = zone;
|
||||
}
|
||||
|
||||
*cnt = c;
|
||||
return zones;
|
||||
}
|
||||
|
||||
static int psz_alloc_zones(struct psz_context *cxt)
|
||||
{
|
||||
struct pstore_zone_info *info = cxt->pstore_zone_info;
|
||||
loff_t off = 0;
|
||||
int err;
|
||||
size_t size;
|
||||
|
||||
size = info->total_size;
|
||||
cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, size,
|
||||
info->kmsg_size, &cxt->kmsg_max_cnt);
|
||||
if (IS_ERR(cxt->kpszs)) {
|
||||
err = PTR_ERR(cxt->kpszs);
|
||||
cxt->kpszs = NULL;
|
||||
goto fail_out;
|
||||
}
|
||||
|
||||
return 0;
|
||||
fail_out:
|
||||
return err;
|
||||
}
|
||||
|
||||
/**
|
||||
* 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)
|
||||
{
|
||||
int err = -EINVAL;
|
||||
struct psz_context *cxt = &pstore_zone_cxt;
|
||||
|
||||
if (info->total_size < 4096) {
|
||||
pr_warn("total_size must be >= 4096\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (!info->kmsg_size) {
|
||||
pr_warn("at least one record size must be non-zero\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (!info->name || !info->name[0])
|
||||
return -EINVAL;
|
||||
|
||||
#define check_size(name, size) { \
|
||||
if (info->name > 0 && info->name < (size)) { \
|
||||
pr_err(#name " must be over %d\n", (size)); \
|
||||
return -EINVAL; \
|
||||
} \
|
||||
if (info->name & (size - 1)) { \
|
||||
pr_err(#name " must be a multiple of %d\n", \
|
||||
(size)); \
|
||||
return -EINVAL; \
|
||||
} \
|
||||
}
|
||||
|
||||
check_size(total_size, 4096);
|
||||
check_size(kmsg_size, SECTOR_SIZE);
|
||||
|
||||
#undef check_size
|
||||
|
||||
/*
|
||||
* the @read and @write must be applied.
|
||||
* if no @read, pstore may mount failed.
|
||||
* if no @write, pstore do not support to remove record file.
|
||||
*/
|
||||
if (!info->read || !info->write) {
|
||||
pr_err("no valid general read/write interface\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
mutex_lock(&cxt->pstore_zone_info_lock);
|
||||
if (cxt->pstore_zone_info) {
|
||||
pr_warn("'%s' already loaded: ignoring '%s'\n",
|
||||
cxt->pstore_zone_info->name, info->name);
|
||||
mutex_unlock(&cxt->pstore_zone_info_lock);
|
||||
return -EBUSY;
|
||||
}
|
||||
cxt->pstore_zone_info = info;
|
||||
|
||||
pr_debug("register %s with properties:\n", info->name);
|
||||
pr_debug("\ttotal size : %ld Bytes\n", info->total_size);
|
||||
pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size);
|
||||
|
||||
err = psz_alloc_zones(cxt);
|
||||
if (err) {
|
||||
pr_err("alloc zones failed\n");
|
||||
goto fail_out;
|
||||
}
|
||||
|
||||
if (info->kmsg_size) {
|
||||
cxt->pstore.bufsize = cxt->kpszs[0]->buffer_size -
|
||||
sizeof(struct psz_kmsg_header);
|
||||
cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
|
||||
if (!cxt->pstore.buf) {
|
||||
err = -ENOMEM;
|
||||
goto fail_free;
|
||||
}
|
||||
}
|
||||
cxt->pstore.data = cxt;
|
||||
|
||||
pr_info("registered %s as backend for", info->name);
|
||||
cxt->pstore.max_reason = info->max_reason;
|
||||
cxt->pstore.name = info->name;
|
||||
if (info->kmsg_size) {
|
||||
cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
|
||||
pr_cont(" kmsg(%s",
|
||||
kmsg_dump_reason_str(cxt->pstore.max_reason));
|
||||
if (cxt->pstore_zone_info->panic_write)
|
||||
pr_cont(",panic_write");
|
||||
pr_cont(")");
|
||||
}
|
||||
pr_cont("\n");
|
||||
|
||||
err = pstore_register(&cxt->pstore);
|
||||
if (err) {
|
||||
pr_err("registering with pstore failed\n");
|
||||
goto fail_free;
|
||||
}
|
||||
mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock);
|
||||
|
||||
return 0;
|
||||
|
||||
fail_free:
|
||||
kfree(cxt->pstore.buf);
|
||||
cxt->pstore.buf = NULL;
|
||||
cxt->pstore.bufsize = 0;
|
||||
psz_free_all_zones(cxt);
|
||||
fail_out:
|
||||
pstore_zone_cxt.pstore_zone_info = NULL;
|
||||
mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock);
|
||||
return err;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(register_pstore_zone);
|
||||
|
||||
/**
|
||||
* 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)
|
||||
{
|
||||
struct psz_context *cxt = &pstore_zone_cxt;
|
||||
|
||||
mutex_lock(&cxt->pstore_zone_info_lock);
|
||||
if (!cxt->pstore_zone_info) {
|
||||
mutex_unlock(&cxt->pstore_zone_info_lock);
|
||||
return;
|
||||
}
|
||||
|
||||
/* Stop incoming writes from pstore. */
|
||||
pstore_unregister(&cxt->pstore);
|
||||
|
||||
/* Clean up allocations. */
|
||||
kfree(cxt->pstore.buf);
|
||||
cxt->pstore.buf = NULL;
|
||||
cxt->pstore.bufsize = 0;
|
||||
cxt->pstore_zone_info = NULL;
|
||||
|
||||
psz_free_all_zones(cxt);
|
||||
|
||||
/* Clear counters and zone state. */
|
||||
cxt->oops_counter = 0;
|
||||
cxt->panic_counter = 0;
|
||||
atomic_set(&cxt->recovered, 0);
|
||||
atomic_set(&cxt->on_panic, 0);
|
||||
|
||||
mutex_unlock(&cxt->pstore_zone_info_lock);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(unregister_pstore_zone);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("WeiXiong Liao <liaoweixiong@allwinnertech.com>");
|
||||
MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
|
||||
MODULE_DESCRIPTION("Storage Manager for pstore/blk");
|
||||
44
include/linux/pstore_zone.h
Normal file
44
include/linux/pstore_zone.h
Normal file
@ -0,0 +1,44 @@
|
||||
/* SPDX-License-Identifier: GPL-2.0 */
|
||||
|
||||
#ifndef __PSTORE_ZONE_H_
|
||||
#define __PSTORE_ZONE_H_
|
||||
|
||||
#include <linux/types.h>
|
||||
|
||||
typedef ssize_t (*pstore_zone_read_op)(char *, size_t, loff_t);
|
||||
typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t);
|
||||
/**
|
||||
* struct pstore_zone_info - pstore/zone back-end driver structure
|
||||
*
|
||||
* @owner: Module which is responsible for this back-end driver.
|
||||
* @name: Name of the back-end driver.
|
||||
* @total_size: The total size in bytes pstore/zone can use. It must be greater
|
||||
* than 4096 and be multiple of 4096.
|
||||
* @kmsg_size: The size of oops/panic zone. Zero means disabled, otherwise,
|
||||
* it must be multiple of SECTOR_SIZE(512 Bytes).
|
||||
* @max_reason: Maximum kmsg dump reason to store.
|
||||
* @read: The general read operation. Both of the function parameters
|
||||
* @size and @offset are relative value to storage.
|
||||
* On success, the number of bytes should be returned, others
|
||||
* means error.
|
||||
* @write: The same as @read.
|
||||
* @panic_write:The write operation only used for panic case. It's optional
|
||||
* if you do not care panic log. The parameters and return value
|
||||
* are the same as @read.
|
||||
*/
|
||||
struct pstore_zone_info {
|
||||
struct module *owner;
|
||||
const char *name;
|
||||
|
||||
unsigned long total_size;
|
||||
unsigned long kmsg_size;
|
||||
int max_reason;
|
||||
pstore_zone_read_op read;
|
||||
pstore_zone_write_op write;
|
||||
pstore_zone_write_op panic_write;
|
||||
};
|
||||
|
||||
extern int register_pstore_zone(struct pstore_zone_info *info);
|
||||
extern void unregister_pstore_zone(struct pstore_zone_info *info);
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user