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 /fs/sysfs/sysfs.h | |
| parent | ec748fa9ed3fec44aeebbf86ae050b0cc7a978d9 (diff) | |
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 'fs/sysfs/sysfs.h')
| -rw-r--r-- | fs/sysfs/sysfs.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index a5db496f71c7..93c6d6b27c4d 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -124,7 +124,7 @@ int sysfs_create_subdir(struct kobject *kobj, const char *name, struct sysfs_dirent **p_sd); void sysfs_remove_subdir(struct sysfs_dirent *sd); -static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd) +static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd) { if (sd) { WARN_ON(!atomic_read(&sd->s_count)); @@ -132,12 +132,14 @@ static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd) } return sd; } +#define sysfs_get(sd) __sysfs_get(sd) -static inline void sysfs_put(struct sysfs_dirent *sd) +static inline void __sysfs_put(struct sysfs_dirent *sd) { if (sd && atomic_dec_and_test(&sd->s_count)) release_sysfs_dirent(sd); } +#define sysfs_put(sd) __sysfs_put(sd) /* * inode.c |