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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /fs/pstore/platform.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'fs/pstore/platform.c')
-rw-r--r-- | fs/pstore/platform.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c new file mode 100644 index 00000000..82c585f7 --- /dev/null +++ b/fs/pstore/platform.c @@ -0,0 +1,261 @@ +/* + * Persistent Storage - platform driver interface parts. + * + * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/atomic.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/kmsg_dump.h> +#include <linux/module.h> +#include <linux/pstore.h> +#include <linux/string.h> +#include <linux/timer.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/hardirq.h> +#include <linux/workqueue.h> + +#include "internal.h" + +/* + * We defer making "oops" entries appear in pstore - see + * whether the system is actually still running well enough + * to let someone see the entry + */ +#define PSTORE_INTERVAL (60 * HZ) + +static int pstore_new_entry; + +static void pstore_timefunc(unsigned long); +static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0); + +static void pstore_dowork(struct work_struct *); +static DECLARE_WORK(pstore_work, pstore_dowork); + +/* + * pstore_lock just protects "psinfo" during + * calls to pstore_register() + */ +static DEFINE_SPINLOCK(pstore_lock); +static struct pstore_info *psinfo; + +static char *backend; + +/* How much of the console log to snapshot */ +static unsigned long kmsg_bytes = 10240; + +void pstore_set_kmsg_bytes(int bytes) +{ + kmsg_bytes = bytes; +} + +/* Tag each group of saved records with a sequence number */ +static int oopscount; + +static const char *get_reason_str(enum kmsg_dump_reason reason) +{ + switch (reason) { + case KMSG_DUMP_PANIC: + return "Panic"; + case KMSG_DUMP_OOPS: + return "Oops"; + case KMSG_DUMP_EMERG: + return "Emergency"; + case KMSG_DUMP_RESTART: + return "Restart"; + case KMSG_DUMP_HALT: + return "Halt"; + case KMSG_DUMP_POWEROFF: + return "Poweroff"; + default: + return "Unknown"; + } +} + +/* + * callback from kmsg_dump. (s2,l2) has the most recently + * written bytes, older bytes are in (s1,l1). Save as much + * as we can from the end of the buffer. + */ +static void pstore_dump(struct kmsg_dumper *dumper, + enum kmsg_dump_reason reason, + const char *s1, unsigned long l1, + const char *s2, unsigned long l2) +{ + unsigned long s1_start, s2_start; + unsigned long l1_cpy, l2_cpy; + unsigned long size, total = 0; + char *dst; + const char *why; + u64 id; + int hsize, ret; + unsigned int part = 1; + unsigned long flags = 0; + int is_locked = 0; + + why = get_reason_str(reason); + + if (in_nmi()) { + is_locked = spin_trylock(&psinfo->buf_lock); + if (!is_locked) + pr_err("pstore dump routine blocked in NMI, may corrupt error record\n"); + } else + spin_lock_irqsave(&psinfo->buf_lock, flags); + oopscount++; + while (total < kmsg_bytes) { + dst = psinfo->buf; + hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part); + size = psinfo->bufsize - hsize; + dst += hsize; + + l2_cpy = min(l2, size); + l1_cpy = min(l1, size - l2_cpy); + + if (l1_cpy + l2_cpy == 0) + break; + + s2_start = l2 - l2_cpy; + s1_start = l1 - l1_cpy; + + memcpy(dst, s1 + s1_start, l1_cpy); + memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy); + + ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part, + hsize + l1_cpy + l2_cpy, psinfo); + if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) + pstore_new_entry = 1; + l1 -= l1_cpy; + l2 -= l2_cpy; + total += l1_cpy + l2_cpy; + part++; + } + if (in_nmi()) { + if (is_locked) + spin_unlock(&psinfo->buf_lock); + } else + spin_unlock_irqrestore(&psinfo->buf_lock, flags); +} + +static struct kmsg_dumper pstore_dumper = { + .dump = pstore_dump, +}; + +/* + * platform specific persistent storage driver registers with + * us here. If pstore is already mounted, call the platform + * read function right away to populate the file system. If not + * then the pstore mount code will call us later to fill out + * the file system. + * + * Register with kmsg_dump to save last part of console log on panic. + */ +int pstore_register(struct pstore_info *psi) +{ + struct module *owner = psi->owner; + + spin_lock(&pstore_lock); + if (psinfo) { + spin_unlock(&pstore_lock); + return -EBUSY; + } + + if (backend && strcmp(backend, psi->name)) { + spin_unlock(&pstore_lock); + return -EINVAL; + } + + psinfo = psi; + mutex_init(&psinfo->read_mutex); + spin_unlock(&pstore_lock); + + if (owner && !try_module_get(owner)) { + psinfo = NULL; + return -EINVAL; + } + + if (pstore_is_mounted()) + pstore_get_records(0); + + kmsg_dump_register(&pstore_dumper); + + pstore_timer.expires = jiffies + PSTORE_INTERVAL; + add_timer(&pstore_timer); + + return 0; +} +EXPORT_SYMBOL_GPL(pstore_register); + +/* + * Read all the records from the persistent store. Create + * files in our filesystem. Don't warn about -EEXIST errors + * when we are re-scanning the backing store looking to add new + * error records. + */ +void pstore_get_records(int quiet) +{ + struct pstore_info *psi = psinfo; + char *buf = NULL; + ssize_t size; + u64 id; + enum pstore_type_id type; + struct timespec time; + int failed = 0, rc; + + if (!psi) + return; + + mutex_lock(&psi->read_mutex); + if (psi->open && psi->open(psi)) + goto out; + + while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) { + rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size, + time, psi); + kfree(buf); + buf = NULL; + if (rc && (rc != -EEXIST || !quiet)) + failed++; + } + if (psi->close) + psi->close(psi); +out: + mutex_unlock(&psi->read_mutex); + + if (failed) + printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n", + failed, psi->name); +} + +static void pstore_dowork(struct work_struct *work) +{ + pstore_get_records(1); +} + +static void pstore_timefunc(unsigned long dummy) +{ + if (pstore_new_entry) { + pstore_new_entry = 0; + schedule_work(&pstore_work); + } + + mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL); +} + +module_param(backend, charp, 0444); +MODULE_PARM_DESC(backend, "Pstore backend to use"); |