aboutsummaryrefslogtreecommitdiff
path: root/fs/sysfs
diff options
context:
space:
mode:
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/dir.c2
-rw-r--r--fs/sysfs/file.c67
-rw-r--r--fs/sysfs/symlink.c88
3 files changed, 54 insertions, 103 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index f281cc6584b..4948d9bc405 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -440,7 +440,7 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
/**
* sysfs_remove_one - remove sysfs_dirent from parent
* @acxt: addrm context to use
- * @sd: sysfs_dirent to be added
+ * @sd: sysfs_dirent to be removed
*
* Mark @sd removed and drop nlink of parent inode if @sd is a
* directory. @sd is unlinked from the children list.
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 4045bdcc4b3..8acf82bba44 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -20,43 +20,6 @@
#include "sysfs.h"
-#define to_sattr(a) container_of(a,struct subsys_attribute, attr)
-
-/*
- * Subsystem file operations.
- * These operations allow subsystems to have files that can be
- * read/written.
- */
-static ssize_t
-subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
-{
- struct kset *kset = to_kset(kobj);
- struct subsys_attribute * sattr = to_sattr(attr);
- ssize_t ret = -EIO;
-
- if (sattr->show)
- ret = sattr->show(kset, page);
- return ret;
-}
-
-static ssize_t
-subsys_attr_store(struct kobject * kobj, struct attribute * attr,
- const char * page, size_t count)
-{
- struct kset *kset = to_kset(kobj);
- struct subsys_attribute * sattr = to_sattr(attr);
- ssize_t ret = -EIO;
-
- if (sattr->store)
- ret = sattr->store(kset, page, count);
- return ret;
-}
-
-static struct sysfs_ops subsys_sysfs_ops = {
- .show = subsys_attr_show,
- .store = subsys_attr_store,
-};
-
/*
* There's one sysfs_buffer for each open file and one
* sysfs_open_dirent for each sysfs_dirent with one or more open
@@ -66,7 +29,7 @@ static struct sysfs_ops subsys_sysfs_ops = {
* sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open
* is protected by sysfs_open_dirent_lock.
*/
-static spinlock_t sysfs_open_dirent_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
struct sysfs_open_dirent {
atomic_t refcnt;
@@ -354,31 +317,23 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
{
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
- struct sysfs_buffer * buffer;
- struct sysfs_ops * ops = NULL;
- int error;
+ struct sysfs_buffer *buffer;
+ struct sysfs_ops *ops;
+ int error = -EACCES;
/* need attr_sd for attr and ops, its parent for kobj */
if (!sysfs_get_active_two(attr_sd))
return -ENODEV;
- /* if the kobject has no ktype, then we assume that it is a subsystem
- * itself, and use ops for it.
- */
- if (kobj->kset && kobj->kset->ktype)
- ops = kobj->kset->ktype->sysfs_ops;
- else if (kobj->ktype)
+ /* every kobject with an attribute needs a ktype assigned */
+ if (kobj->ktype && kobj->ktype->sysfs_ops)
ops = kobj->ktype->sysfs_ops;
- else
- ops = &subsys_sysfs_ops;
-
- error = -EACCES;
-
- /* No sysfs operations, either from having no subsystem,
- * or the subsystem have no operations.
- */
- if (!ops)
+ else {
+ printk(KERN_ERR "missing sysfs attribute operations for "
+ "kobject: %s\n", kobject_name(kobj));
+ WARN_ON(1);
goto err_out;
+ }
/* File needs write support.
* The inode's perms must say it's ok,
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 3eac20c63c4..5f66c446615 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -19,39 +19,6 @@
#include "sysfs.h"
-static int object_depth(struct sysfs_dirent *sd)
-{
- int depth = 0;
-
- for (; sd->s_parent; sd = sd->s_parent)
- depth++;
-
- return depth;
-}
-
-static int object_path_length(struct sysfs_dirent * sd)
-{
- int length = 1;
-
- for (; sd->s_parent; sd = sd->s_parent)
- length += strlen(sd->s_name) + 1;
-
- return length;
-}
-
-static void fill_object_path(struct sysfs_dirent *sd, char *buffer, int length)
-{
- --length;
- for (; sd->s_parent; sd = sd->s_parent) {
- int cur = strlen(sd->s_name);
-
- /* back up enough to print this bus id with '/' */
- length -= cur;
- strncpy(buffer + length, sd->s_name, cur);
- *(buffer + --length) = '/';
- }
-}
-
/**
* sysfs_create_link - create symlink between two objects.
* @kobj: object whose directory we're creating the link in.
@@ -112,7 +79,6 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
return error;
}
-
/**
* sysfs_remove_link - remove symlink in object's directory.
* @kobj: object we're acting for.
@@ -124,24 +90,54 @@ void sysfs_remove_link(struct kobject * kobj, const char * name)
sysfs_hash_and_remove(kobj->sd, name);
}
-static int sysfs_get_target_path(struct sysfs_dirent * parent_sd,
- struct sysfs_dirent * target_sd, char *path)
+static int sysfs_get_target_path(struct sysfs_dirent *parent_sd,
+ struct sysfs_dirent *target_sd, char *path)
{
- char * s;
- int depth, size;
+ struct sysfs_dirent *base, *sd;
+ char *s = path;
+ int len = 0;
+
+ /* go up to the root, stop at the base */
+ base = parent_sd;
+ while (base->s_parent) {
+ sd = target_sd->s_parent;
+ while (sd->s_parent && base != sd)
+ sd = sd->s_parent;
+
+ if (base == sd)
+ break;
+
+ strcpy(s, "../");
+ s += 3;
+ base = base->s_parent;
+ }
+
+ /* determine end of target string for reverse fillup */
+ sd = target_sd;
+ while (sd->s_parent && sd != base) {
+ len += strlen(sd->s_name) + 1;
+ sd = sd->s_parent;
+ }
- depth = object_depth(parent_sd);
- size = object_path_length(target_sd) + depth * 3 - 1;
- if (size > PATH_MAX)
+ /* check limits */
+ if (len < 2)
+ return -EINVAL;
+ len--;
+ if ((s - path) + len > PATH_MAX)
return -ENAMETOOLONG;
- pr_debug("%s: depth = %d, size = %d\n", __FUNCTION__, depth, size);
+ /* reverse fillup of target string from target to base */
+ sd = target_sd;
+ while (sd->s_parent && sd != base) {
+ int slen = strlen(sd->s_name);
- for (s = path; depth--; s += 3)
- strcpy(s,"../");
+ len -= slen;
+ strncpy(s + len, sd->s_name, slen);
+ if (len)
+ s[--len] = '/';
- fill_object_path(target_sd, path, size);
- pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
+ sd = sd->s_parent;
+ }
return 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 17:44:11 +0000