diff options
author | Neil Brown <neilb@suse.de> | 2008-07-16 08:58:04 +1000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-16 09:24:47 -0700 |
commit | f1282c844e86db5a041afa41335b5f9eea6cec0c (patch) | |
tree | 3736285f2f7ce145fb06538d616a9c1165ffc125 /include/linux/sysfs.h | |
parent | ec748fa9ed3fec44aeebbf86ae050b0cc7a978d9 (diff) | |
download | op-kernel-dev-f1282c844e86db5a041afa41335b5f9eea6cec0c.zip op-kernel-dev-f1282c844e86db5a041afa41335b5f9eea6cec0c.tar.gz |
sysfs: Support sysfs_notify from atomic context with new sysfs_notify_dirent
Support sysfs_notify from atomic context with new sysfs_notify_dirent
sysfs_notify currently takes sysfs_mutex.
This means that it cannot be called in atomic context.
sysfs_mutex is sometimes held over a malloc (sysfs_rename_dir)
so it can block on low memory.
In md I want to be able to notify on a sysfs attribute from
atomic context, and I don't want to block on low memory because I
could be in the writeout path for freeing memory.
So:
- export the "sysfs_dirent" structure along with sysfs_get, sysfs_put
and sysfs_get_dirent so I can get the sysfs_dirent that I want to
notify on and hold it in an md structure.
- split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent
can be notified on with no blocking (just a spinlock).
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux/sysfs.h')
-rw-r--r-- | include/linux/sysfs.h | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 8ec406a..d8e0230 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -78,6 +78,8 @@ struct sysfs_ops { ssize_t (*store)(struct kobject *,struct attribute *,const char *, size_t); }; +struct sysfs_dirent; + #ifdef CONFIG_SYSFS int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), @@ -118,10 +120,13 @@ void sysfs_remove_file_from_group(struct kobject *kobj, const struct attribute *attr, const char *group); void sysfs_notify(struct kobject *kobj, char *dir, char *attr); - +void sysfs_notify_dirent(struct sysfs_dirent *sd); +struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name); +struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd); +void sysfs_put(struct sysfs_dirent *sd); void sysfs_printk_last_file(void); - -extern int __must_check sysfs_init(void); +int __must_check sysfs_init(void); #else /* CONFIG_SYSFS */ @@ -227,6 +232,22 @@ static inline void sysfs_remove_file_from_group(struct kobject *kobj, static inline void sysfs_notify(struct kobject *kobj, char *dir, char *attr) { } +static inline void sysfs_notify_dirent(struct sysfs_dirent *sd) +{ +} +static inline +struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name) +{ + return NULL; +} +static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd) +{ + return NULL; +} +static inline void sysfs_put(struct sysfs_dirent *sd) +{ +} static inline int __must_check sysfs_init(void) { |