pstore 从oops发生到保存dmesg的过程

./kernel/panic.c:13:#include<linux/kmsg_dump.h>

./kernel/panic.c:136: kmsg_dump(KMSG_DUMP_PANIC);

./kernel/panic.c:411: kmsg_dump(KMSG_DUMP_OOPS);

linux/kmsg_dump.h的内容

enumkmsg_dump_reason {

KMSG_DUMP_UNDEF,

KMSG_DUMP_PANIC,

KMSG_DUMP_OOPS,

KMSG_DUMP_EMERG,

KMSG_DUMP_RESTART,

KMSG_DUMP_HALT,

KMSG_DUMP_POWEROFF,

};

/**

*struct kmsg_dumper - kernel crash message dumper structure

*@list: Entry in the dumper list (private)

*@dump: Call into dumping code which will retrieve the data with

*through the record iterator

*@max_reason: filter for highest reason number that should be dumped

*@registered: Flag that specifies if this is already registered

*/

structkmsg_dumper {

structlist_head list;

void(*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason);

enumkmsg_dump_reason max_reason;

boolactive;

boolregistered;

/*private state of the kmsg iterator */

u32cur_idx;

u32next_idx;

u64cur_seq;

u64next_seq;

};

#ifdefCONFIG_PRINTK

voidkmsg_dump(enum kmsg_dump_reason reason);

boolkmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,

char *line, size_t size, size_t *len);

boolkmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,

char*line, size_t size, size_t *len);

boolkmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,

char *buf, size_t size, size_t *len);

voidkmsg_dump_rewind_nolock(struct kmsg_dumper *dumper);

voidkmsg_dump_rewind(struct kmsg_dumper *dumper);

intkmsg_dump_register(struct kmsg_dumper *dumper);

intkmsg_dump_unregister(struct kmsg_dumper *dumper);

注册kmsg_dump_register的实现在printk文件中

pstore是注册的是什么样的函数?

./fs/pstore/platform.c:445: kmsg_dump_register(&pstore_dumper);

staticstruct kmsg_dumper pstore_dumper = {

.dump= pstore_dump,

};

pstore_dump->psinfo->write(PSTORE_TYPE_DMESG, reason, &id,part,

oopscount, compressed, total_len, psinfo);

structpstore_info *psinfo;

staticchar *backend;

./ram.c:503: err= pstore_register(&cxt->pstore);

staticint ramoops_probe(struct platform_device *pdev)

{

structdevice *dev = &pdev->dev;

structramoops_platform_data *pdata = pdev->dev.platform_data;

structramoops_context *cxt = &oops_cxt;

size_tdump_mem_sz;

phys_addr_tpaddr;

interr = -

=====

}

./pstore.h:47:structpstore_info {

/*types */

enumpstore_type_id {

PSTORE_TYPE_DMESG =0,

PSTORE_TYPE_MCE =1,

PSTORE_TYPE_CONSOLE =2,

PSTORE_TYPE_FTRACE =3,

/*PPC64 partition types */

PSTORE_TYPE_PPC_RTAS =4,

PSTORE_TYPE_PPC_OF =5,

PSTORE_TYPE_PPC_COMMON =6,

PSTORE_TYPE_UNKNOWN =255

};

structmodule;

structpstore_info {

structmodule *owner;

char *name;

spinlock_t buf_lock; /*serialize access to 'buf' */

char *buf;

size_t bufsize;

structmutex read_mutex; /* serialize open/read/close */

int flags;

int (*open)(structpstore_info *psi);

int (*close)(structpstore_info *psi);

ssize_t (*read)(u64*id, enum pstore_type_id *type,

int*count, struct timespec *time, char **buf,

bool*compressed, struct pstore_info *psi);

int (*write)(enumpstore_type_id type,

enumkmsg_dump_reason reason, u64 *id,

unsignedint part, int count, bool compressed,

size_tsize, struct pstore_info *psi);

int (*write_buf)(enumpstore_type_id type,

enumkmsg_dump_reason reason, u64 *id,

unsignedint part, const char *buf, bool compressed,

size_tsize, struct pstore_info *psi);

int (*erase)(enumpstore_type_id type, u64 id,

intcount, struct timespec time,

structpstore_info *psi);

void *data;

};

#define PSTORE_FLAGS_FRAGILE 1

#ifdefCONFIG_PSTORE

externint pstore_register(struct pstore_info *);

externbool pstore_cannot_block_path(enum kmsg_dump_reason reason);

staticstruct ramoops_context oops_cxt = {

.pstore= {

.owner =THIS_MODULE,

.name ="ramoops",

.open =ramoops_pstore_open,

.read =ramoops_pstore_read,

.write_buf =ramoops_pstore_write_buf,

.erase =ramoops_pstore_erase,

},

};

platform.c

intpstore_register(struct pstore_info *psi)

{

structmodule *owner = psi->owner;

if(backend && strcmp(backend, psi->name))

return-EPERM;

spin_lock(&pstore_lock);

if(psinfo) {

spin_unlock(&pstore_lock);

return-EBUSY;

}

if(!psi->write)

psi->write= pstore_write_compat;

psinfo= psi;

下一步,哪里通过 pstore文件系统,把保存的数据读出的?