xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Browse Source 
Pull pstore patches from Tony Luck:
 "A few fixes to reduce places where pstore might hang a system in the
  crash path.  Plus a new mountpoint (/sys/fs/pstore ...  makes more
  sense then /dev/pstore)."

Fix up trivial conflict in drivers/firmware/efivars.c

* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  pstore: Create a convenient mount point for pstore
  efi_pstore: Introducing workqueue updating sysfs
  efivars: Disable external interrupt while holding efivars->lock
  efi_pstore: Avoid deadlock in non-blocking paths
  pstore: Avoid deadlock in panic and emergency-restart path
This commit is contained in:
Linus Torvalds
2013-02-21 09:38:18 -08:00
parent 850cb82b75 fb0af3f2b1
commit 024e4ec185
6 changed files with 191 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
fs/pstore/inode.c
View File

@@ -418,9 +418,25 @@ static struct file_system_type pstore_fs_type = {
.kill_sb = pstore_kill_sb,
};
static struct kobject *pstore_kobj;
static int __init init_pstore_fs(void)
{
return register_filesystem(&pstore_fs_type);
int err = 0;
/* Create a convenient mount point for people to access pstore */
pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
if (!pstore_kobj) {
err = -ENOMEM;
goto out;
}
err = register_filesystem(&pstore_fs_type);
if (err < 0)
kobject_put(pstore_kobj);
out:
return err;
}
module_init(init_pstore_fs)

35
fs/pstore/platform.c
View File

@@ -96,6 +96,27 @@ static const char *get_reason_str(enum kmsg_dump_reason reason)
}
}
bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
{
/*
* In case of NMI path, pstore shouldn't be blocked
* regardless of reason.
*/
if (in_nmi())
return true;
switch (reason) {
/* In panic case, other cpus are stopped by smp_send_stop(). */
case KMSG_DUMP_PANIC:
/* Emergency restart shouldn't be blocked by spin lock. */
case KMSG_DUMP_EMERG:
return true;
default:
return false;
}
}
EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
/*
* callback from kmsg_dump. (s2,l2) has the most recently
* written bytes, older bytes are in (s1,l1). Save as much
@@ -114,10 +135,12 @@ static void pstore_dump(struct kmsg_dumper *dumper,
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");
if (pstore_cannot_block_path(reason)) {
is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
if (!is_locked) {
pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
, in_nmi() ? "NMI" : why);
}
} else
spin_lock_irqsave(&psinfo->buf_lock, flags);
oopscount++;
@@ -143,9 +166,9 @@ static void pstore_dump(struct kmsg_dumper *dumper,
total += hsize + len;
part++;
}
if (in_nmi()) {
if (pstore_cannot_block_path(reason)) {
if (is_locked)
spin_unlock(&psinfo->buf_lock);
spin_unlock_irqrestore(&psinfo->buf_lock, flags);
} else
spin_unlock_irqrestore(&psinfo->buf_lock, flags);
}