diff options
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 4ad3721a991..dfe928a9540 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -102,6 +102,22 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, return battr->read(of->file, kobj, battr, buf, pos, count); } +/* kernfs read callback for regular sysfs files with pre-alloc */ +static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf, + size_t count, loff_t pos) +{ + const struct sysfs_ops *ops = sysfs_file_ops(of->kn); + struct kobject *kobj = of->kn->parent->priv; + + /* + * If buf != of->prealloc_buf, we don't know how + * large it is, so cannot safely pass it to ->show + */ + if (pos || WARN_ON_ONCE(buf != of->prealloc_buf)) + return 0; + return ops->show(kobj, of->kn->priv, buf); +} + /* kernfs write callback for regular sysfs files */ static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) @@ -184,13 +200,18 @@ static const struct kernfs_ops sysfs_file_kfops_rw = { .write = sysfs_kf_write, }; +static const struct kernfs_ops sysfs_prealloc_kfops_ro = { + .read = sysfs_kf_read, + .prealloc = true, +}; + static const struct kernfs_ops sysfs_prealloc_kfops_wo = { .write = sysfs_kf_write, .prealloc = true, }; static const struct kernfs_ops sysfs_prealloc_kfops_rw = { - .seq_show = sysfs_kf_seq_show, + .read = sysfs_kf_read, .write = sysfs_kf_write, .prealloc = true, }; @@ -238,9 +259,12 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent, ops = &sysfs_prealloc_kfops_rw; else ops = &sysfs_file_kfops_rw; - } else if (sysfs_ops->show) - ops = &sysfs_file_kfops_ro; - else if (sysfs_ops->store) { + } else if (sysfs_ops->show) { + if (mode & SYSFS_PREALLOC) + ops = &sysfs_prealloc_kfops_ro; + else + ops = &sysfs_file_kfops_ro; + } else if (sysfs_ops->store) { if (mode & SYSFS_PREALLOC) ops = &sysfs_prealloc_kfops_wo; else |