diff options
| -rw-r--r-- | fs/sysfs/file.c | 39 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 9 |
2 files changed, 35 insertions, 13 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 9852450867cf..74e3478d9cb4 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -146,6 +146,7 @@ static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) { struct sysfs_open_file *of = sf->private; + const struct kernfs_ops *ops; /* * @of->mutex nests outside active ref and is just to ensure that @@ -155,26 +156,42 @@ static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) if (!sysfs_get_active(of->sd)) return ERR_PTR(-ENODEV); - /* - * The same behavior and code as single_open(). Returns !NULL if - * pos is at the beginning; otherwise, NULL. - */ - return NULL + !*ppos; + ops = kernfs_ops(of->sd); + if (ops->seq_start) { + return ops->seq_start(sf, ppos); + } else { + /* + * The same behavior and code as single_open(). Returns + * !NULL if pos is at the beginning; otherwise, NULL. + */ + return NULL + !*ppos; + } } static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) { - /* - * The same behavior and code as single_open(), always terminate - * after the initial read. - */ - ++*ppos; - return NULL; + struct sysfs_open_file *of = sf->private; + const struct kernfs_ops *ops = kernfs_ops(of->sd); + + if (ops->seq_next) { + return ops->seq_next(sf, v, ppos); + } else { + /* + * The same behavior and code as single_open(), always + * terminate after the initial read. + */ + ++*ppos; + return NULL; + } } static void kernfs_seq_stop(struct seq_file *sf, void *v) { struct sysfs_open_file *of = sf->private; + const struct kernfs_ops *ops = kernfs_ops(of->sd); + + if (ops->seq_stop) + ops->seq_stop(sf, v); sysfs_put_active(of->sd); mutex_unlock(&of->mutex); diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index d0912cf02087..ba993ebcd81e 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -37,8 +37,9 @@ struct kernfs_ops { /* * Read is handled by either seq_file or raw_read(). * - * If seq_show() is present, seq_file path is active. The behavior - * is equivalent to single_open(). @sf->private points to the + * If seq_show() is present, seq_file path is active. Other seq + * operations are optional and if not implemented, the behavior is + * equivalent to single_open(). @sf->private points to the * associated sysfs_open_file. * * read() is bounced through kernel buffer and a read larger than @@ -46,6 +47,10 @@ struct kernfs_ops { */ int (*seq_show)(struct seq_file *sf, void *v); + void *(*seq_start)(struct seq_file *sf, loff_t *ppos); + void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos); + void (*seq_stop)(struct seq_file *sf, void *v); + ssize_t (*read)(struct sysfs_open_file *of, char *buf, size_t bytes, loff_t off); |
