diff options
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 59 |
1 files changed, 50 insertions, 9 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index e9ef59b3abb1..dfe928a9540f 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) @@ -125,7 +141,7 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf, if (size) { if (size <= pos) - return 0; + return -EFBIG; count = min_t(ssize_t, count, size - pos); } if (!count) @@ -184,6 +200,22 @@ 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 = { + .read = sysfs_kf_read, + .write = sysfs_kf_write, + .prealloc = true, +}; + static const struct kernfs_ops sysfs_bin_kfops_ro = { .read = sysfs_kf_bin_read, }; @@ -222,13 +254,22 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent, kobject_name(kobj))) return -EINVAL; - if (sysfs_ops->show && sysfs_ops->store) - ops = &sysfs_file_kfops_rw; - else if (sysfs_ops->show) - ops = &sysfs_file_kfops_ro; - else if (sysfs_ops->store) - ops = &sysfs_file_kfops_wo; - else + if (sysfs_ops->show && sysfs_ops->store) { + if (mode & SYSFS_PREALLOC) + ops = &sysfs_prealloc_kfops_rw; + else + ops = &sysfs_file_kfops_rw; + } 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 + ops = &sysfs_file_kfops_wo; + } else ops = &sysfs_file_kfops_empty; size = PAGE_SIZE; @@ -253,7 +294,7 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent, if (!attr->ignore_lockdep) key = attr->key ?: (struct lock_class_key *)&attr->skey; #endif - kn = __kernfs_create_file(parent, attr->name, mode, size, ops, + kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops, (void *)attr, ns, true, key); if (IS_ERR(kn)) { if (PTR_ERR(kn) == -EEXIST) |