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Diffstat (limited to 'fs/sysfs/file.c')
-rw-r--r--fs/sysfs/file.c83
1 files changed, 65 insertions, 18 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 6b7652fb8050..c3d3b079aedd 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -19,13 +19,19 @@
#include "sysfs.h"
+static struct kobject *sysfs_file_kobj(struct kernfs_node *kn)
+{
+ guard(rcu)();
+ return rcu_dereference(kn->__parent)->priv;
+}
+
/*
* Determine ktype->sysfs_ops for the given kernfs_node. This function
* must be called while holding an active reference.
*/
static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
{
- struct kobject *kobj = kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(kn);
if (kn->flags & KERNFS_LOCKDEP)
lockdep_assert_held(kn);
@@ -40,7 +46,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
{
struct kernfs_open_file *of = sf->private;
- struct kobject *kobj = of->kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
ssize_t count;
char *buf;
@@ -78,7 +84,7 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
size_t count, loff_t pos)
{
struct bin_attribute *battr = of->kn->priv;
- struct kobject *kobj = of->kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
loff_t size = file_inode(of->file)->i_size;
if (!count)
@@ -91,9 +97,12 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
count = size - pos;
}
- if (!battr->read)
+ if (!battr->read && !battr->read_new)
return -EIO;
+ if (battr->read_new)
+ return battr->read_new(of->file, kobj, battr, buf, pos, count);
+
return battr->read(of->file, kobj, battr, buf, pos, count);
}
@@ -102,7 +111,7 @@ 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;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
ssize_t len;
/*
@@ -128,7 +137,7 @@ static ssize_t sysfs_kf_write(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;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
if (!count)
return 0;
@@ -141,7 +150,7 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
size_t count, loff_t pos)
{
struct bin_attribute *battr = of->kn->priv;
- struct kobject *kobj = of->kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
loff_t size = file_inode(of->file)->i_size;
if (size) {
@@ -152,9 +161,12 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
if (!count)
return 0;
- if (!battr->write)
+ if (!battr->write && !battr->write_new)
return -EIO;
+ if (battr->write_new)
+ return battr->write_new(of->file, kobj, battr, buf, pos, count);
+
return battr->write(of->file, kobj, battr, buf, pos, count);
}
@@ -162,7 +174,7 @@ static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
struct vm_area_struct *vma)
{
struct bin_attribute *battr = of->kn->priv;
- struct kobject *kobj = of->kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
return battr->mmap(of->file, kobj, battr, vma);
}
@@ -171,7 +183,7 @@ static loff_t sysfs_kf_bin_llseek(struct kernfs_open_file *of, loff_t offset,
int whence)
{
struct bin_attribute *battr = of->kn->priv;
- struct kobject *kobj = of->kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(of->kn);
if (battr->llseek)
return battr->llseek(of->file, kobj, battr, offset, whence);
@@ -315,7 +327,7 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent,
}
int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
- const struct bin_attribute *battr, umode_t mode,
+ const struct bin_attribute *battr, umode_t mode, size_t size,
kuid_t uid, kgid_t gid, const void *ns)
{
const struct attribute *attr = &battr->attr;
@@ -323,13 +335,19 @@ int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
const struct kernfs_ops *ops;
struct kernfs_node *kn;
+ if (battr->read && battr->read_new)
+ return -EINVAL;
+
+ if (battr->write && battr->write_new)
+ return -EINVAL;
+
if (battr->mmap)
ops = &sysfs_bin_kfops_mmap;
- else if (battr->read && battr->write)
+ else if ((battr->read || battr->read_new) && (battr->write || battr->write_new))
ops = &sysfs_bin_kfops_rw;
- else if (battr->read)
+ else if (battr->read || battr->read_new)
ops = &sysfs_bin_kfops_ro;
- else if (battr->write)
+ else if (battr->write || battr->write_new)
ops = &sysfs_bin_kfops_wo;
else
ops = &sysfs_file_kfops_empty;
@@ -340,7 +358,7 @@ int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
#endif
kn = __kernfs_create_file(parent, attr->name, mode & 0777, uid, gid,
- battr->size, ops, (void *)attr, ns, key);
+ size, ops, (void *)attr, ns, key);
if (IS_ERR(kn)) {
if (PTR_ERR(kn) == -EEXIST)
sysfs_warn_dup(parent, attr->name);
@@ -463,6 +481,8 @@ struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
kn = kernfs_find_and_get(kobj->sd, attr->name);
if (kn)
kernfs_break_active_protection(kn);
+ else
+ kobject_put(kobj);
return kn;
}
EXPORT_SYMBOL_GPL(sysfs_break_active_protection);
@@ -480,7 +500,7 @@ EXPORT_SYMBOL_GPL(sysfs_break_active_protection);
*/
void sysfs_unbreak_active_protection(struct kernfs_node *kn)
{
- struct kobject *kobj = kn->parent->priv;
+ struct kobject *kobj = sysfs_file_kobj(kn);
kernfs_unbreak_active_protection(kn);
kernfs_put(kn);
@@ -578,8 +598,8 @@ int sysfs_create_bin_file(struct kobject *kobj,
return -EINVAL;
kobject_get_ownership(kobj, &uid, &gid);
- return sysfs_add_bin_file_mode_ns(kobj->sd, attr, attr->attr.mode, uid,
- gid, NULL);
+ return sysfs_add_bin_file_mode_ns(kobj->sd, attr, attr->attr.mode,
+ attr->size, uid, gid, NULL);
}
EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
@@ -783,3 +803,30 @@ int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
return len;
}
EXPORT_SYMBOL_GPL(sysfs_emit_at);
+
+/**
+ * sysfs_bin_attr_simple_read - read callback to simply copy from memory.
+ * @file: attribute file which is being read.
+ * @kobj: object to which the attribute belongs.
+ * @attr: attribute descriptor.
+ * @buf: destination buffer.
+ * @off: offset in bytes from which to read.
+ * @count: maximum number of bytes to read.
+ *
+ * Simple ->read() callback for bin_attributes backed by a buffer in memory.
+ * The @private and @size members in struct bin_attribute must be set to the
+ * buffer's location and size before the bin_attribute is created in sysfs.
+ *
+ * Bounds check for @off and @count is done in sysfs_kf_bin_read().
+ * Negative value check for @off is done in vfs_setpos() and default_llseek().
+ *
+ * Returns number of bytes written to @buf.
+ */
+ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj,
+ const struct bin_attribute *attr, char *buf,
+ loff_t off, size_t count)
+{
+ memcpy(buf, attr->private + off, count);
+ return count;
+}
+EXPORT_SYMBOL_GPL(sysfs_bin_attr_simple_read);
generated by cgit (git 2.34.1) at 2025-07-16 03:16:04 +0000