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author | Tejun Heo <tj@kernel.org> | 2013-11-28 14:54:26 -0500 |
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committer | Pawel Osmialowski <p.osmialowsk@mcdsrvbld02.digital.local> | 2015-03-27 14:37:30 +0100 |
commit | ea72c71344e75459493113b7d264f5973ebdcfb8 (patch) | |
tree | ce2d5c2029d602dc913563b55b98d5d35f91277b /fs | |
parent | a09bb738478e1360b12f310c6b1af92cc51c5158 (diff) | |
download | linux-3.10-ea72c71344e75459493113b7d264f5973ebdcfb8.tar.gz linux-3.10-ea72c71344e75459493113b7d264f5973ebdcfb8.tar.bz2 linux-3.10-ea72c71344e75459493113b7d264f5973ebdcfb8.zip |
sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}()
kernfs_ops currently only supports single_open() behavior which is
pretty restrictive. Add optional callbacks ->seq_{start|next|stop}()
which, when implemented, are invoked for seq_file traversal. This
allows full seq_file functionality for kernfs users. This currently
doesn't have any user and doesn't change any behavior.
v2: Refreshed on top of the updated "sysfs, kernfs: prepare read path
for kernfs".
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/sysfs/file.c | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 41a1e0accc0..ef89b3cfc41 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -147,6 +147,7 @@ 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 @@ -156,26 +157,42 @@ 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); |