diff options
author | John Gallagher <[email protected]> | 2018-09-26 11:08:12 -0700 |
---|---|---|
committer | Brian Behlendorf <[email protected]> | 2018-09-26 11:08:12 -0700 |
commit | d12614521a307c709778e5f7f91ae6085f63f9e0 (patch) | |
tree | 130e6dde286d0da760612a7f4d9595a660777011 /include/spl/sys/kstat.h | |
parent | 3ed2fbcc1ce36fdc516aa11848692a4e4c4a2bc0 (diff) |
Fixes for procfs files backed by linked lists
There are some issues with the way the seq_file interface is implemented
for kstats backed by linked lists (zfs_dbgmsgs and certain per-pool
debugging info):
* We don't account for the fact that seq_file sometimes visits a node
multiple times, which results in missing messages when read through
procfs.
* We don't keep separate state for each reader of a file, so concurrent
readers will receive incorrect results.
* We don't account for the fact that entries may have been removed from
the list between read syscalls, so reading from these files in procfs
can cause the system to crash.
This change fixes these issues and adds procfs_list, a wrapper around a
linked list which abstracts away the details of implementing the
seq_file interface for a list and exposing the contents of the list
through procfs.
Reviewed by: Don Brady <[email protected]>
Reviewed-by: Serapheim Dimitropoulos <[email protected]>
Reviewed by: Brad Lewis <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: John Gallagher <[email protected]>
External-issue: LX-1211
Closes #7819
Diffstat (limited to 'include/spl/sys/kstat.h')
-rw-r--r-- | include/spl/sys/kstat.h | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/include/spl/sys/kstat.h b/include/spl/sys/kstat.h index f197ce455..53274d8f5 100644 --- a/include/spl/sys/kstat.h +++ b/include/spl/sys/kstat.h @@ -98,30 +98,34 @@ typedef struct kstat_raw_ops { void *(*addr)(kstat_t *ksp, loff_t index); } kstat_raw_ops_t; +typedef struct kstat_proc_entry { + char kpe_name[KSTAT_STRLEN+1]; /* kstat name */ + char kpe_module[KSTAT_STRLEN+1]; /* provider module name */ + kstat_module_t *kpe_owner; /* kstat module linkage */ + struct list_head kpe_list; /* kstat linkage */ + struct proc_dir_entry *kpe_proc; /* procfs entry */ +} kstat_proc_entry_t; + struct kstat_s { int ks_magic; /* magic value */ kid_t ks_kid; /* unique kstat ID */ hrtime_t ks_crtime; /* creation time */ hrtime_t ks_snaptime; /* last access time */ - char ks_module[KSTAT_STRLEN+1]; /* provider module name */ int ks_instance; /* provider module instance */ - char ks_name[KSTAT_STRLEN+1]; /* kstat name */ char ks_class[KSTAT_STRLEN+1]; /* kstat class */ uchar_t ks_type; /* kstat data type */ uchar_t ks_flags; /* kstat flags */ void *ks_data; /* kstat type-specific data */ uint_t ks_ndata; /* # of data records */ size_t ks_data_size; /* size of kstat data section */ - struct proc_dir_entry *ks_proc; /* proc linkage */ kstat_update_t *ks_update; /* dynamic updates */ void *ks_private; /* private data */ kmutex_t ks_private_lock; /* kstat private data lock */ kmutex_t *ks_lock; /* kstat data lock */ - struct list_head ks_list; /* kstat linkage */ - kstat_module_t *ks_owner; /* kstat module linkage */ kstat_raw_ops_t ks_raw_ops; /* ops table for raw type */ char *ks_raw_buf; /* buf used for raw ops */ size_t ks_raw_bufsize; /* size of raw ops buffer */ + kstat_proc_entry_t ks_proc; /* data for procfs entry */ }; typedef struct kstat_named_s { @@ -189,6 +193,12 @@ extern kstat_t *__kstat_create(const char *ks_module, int ks_instance, const char *ks_name, const char *ks_class, uchar_t ks_type, uint_t ks_ndata, uchar_t ks_flags); +extern void kstat_proc_entry_init(kstat_proc_entry_t *kpep, + const char *module, const char *name); +extern void kstat_proc_entry_delete(kstat_proc_entry_t *kpep); +extern void kstat_proc_entry_install(kstat_proc_entry_t *kpep, + const struct file_operations *file_ops, void *data); + extern void __kstat_install(kstat_t *ksp); extern void __kstat_delete(kstat_t *ksp); extern void kstat_waitq_enter(kstat_io_t *); |