diff options
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/inode.c | 18 | ||||
| -rw-r--r-- | fs/pstore/platform.c | 35 |
2 files changed, 46 insertions, 7 deletions
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 67de74ca85f..e4bcb2cf055 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -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) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 5ea2e77ff02..86d1038b5a1 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -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); } |