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-rw-r--r--fs/kernfs/dir.c61
-rw-r--r--fs/sysfs/dir.c6
-rw-r--r--include/linux/cgroup.h7
-rw-r--r--include/linux/kernfs.h21
4 files changed, 42 insertions, 53 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index e57174d43683..09242aaa8829 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -110,8 +110,9 @@ static struct kernfs_node *kernfs_common_ancestor(struct kernfs_node *a,
* kn_to: /n1/n2/n3 [depth=3]
* result: /../..
*
- * return value: length of the string. If greater than buflen,
- * then contents of buf are undefined. On error, -1 is returned.
+ * Returns the length of the full path. If the full length is equal to or
+ * greater than @buflen, @buf contains the truncated path with the trailing
+ * '\0'. On error, -errno is returned.
*/
static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
struct kernfs_node *kn_from,
@@ -119,9 +120,8 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
{
struct kernfs_node *kn, *common;
const char parent_str[] = "/..";
- size_t depth_from, depth_to, len = 0, nlen = 0;
- char *p;
- int i;
+ size_t depth_from, depth_to, len = 0;
+ int i, j;
if (!kn_from)
kn_from = kernfs_root(kn_to)->kn;
@@ -131,7 +131,7 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
common = kernfs_common_ancestor(kn_from, kn_to);
if (WARN_ON(!common))
- return -1;
+ return -EINVAL;
depth_to = kernfs_depth(common, kn_to);
depth_from = kernfs_depth(common, kn_from);
@@ -144,22 +144,16 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
len < buflen ? buflen - len : 0);
/* Calculate how many bytes we need for the rest */
- for (kn = kn_to; kn != common; kn = kn->parent)
- nlen += strlen(kn->name) + 1;
-
- if (len + nlen >= buflen)
- return len + nlen;
-
- p = buf + len + nlen;
- *p = '\0';
- for (kn = kn_to; kn != common; kn = kn->parent) {
- size_t tmp = strlen(kn->name);
- p -= tmp;
- memcpy(p, kn->name, tmp);
- *(--p) = '/';
+ for (i = depth_to - 1; i >= 0; i--) {
+ for (kn = kn_to, j = 0; j < i; j++)
+ kn = kn->parent;
+ len += strlcpy(buf + len, "/",
+ len < buflen ? buflen - len : 0);
+ len += strlcpy(buf + len, kn->name,
+ len < buflen ? buflen - len : 0);
}
- return len + nlen;
+ return len;
}
/**
@@ -220,8 +214,9 @@ size_t kernfs_path_len(struct kernfs_node *kn)
* path (which includes '..'s) as needed to reach from @from to @to is
* returned.
*
- * If @buf isn't long enough, the return value will be greater than @buflen
- * and @buf contents are undefined.
+ * Returns the length of the full path. If the full length is equal to or
+ * greater than @buflen, @buf contains the truncated path with the trailing
+ * '\0'. On error, -errno is returned.
*/
int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from,
char *buf, size_t buflen)
@@ -237,28 +232,6 @@ int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from,
EXPORT_SYMBOL_GPL(kernfs_path_from_node);
/**
- * kernfs_path - build full path of a given node
- * @kn: kernfs_node of interest
- * @buf: buffer to copy @kn's name into
- * @buflen: size of @buf
- *
- * Builds and returns the full path of @kn in @buf of @buflen bytes. The
- * path is built from the end of @buf so the returned pointer usually
- * doesn't match @buf. If @buf isn't long enough, @buf is nul terminated
- * and %NULL is returned.
- */
-char *kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen)
-{
- int ret;
-
- ret = kernfs_path_from_node(kn, NULL, buf, buflen);
- if (ret < 0 || ret >= buflen)
- return NULL;
- return buf;
-}
-EXPORT_SYMBOL_GPL(kernfs_path);
-
-/**
* pr_cont_kernfs_name - pr_cont name of a kernfs_node
* @kn: kernfs_node of interest
*
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 94374e435025..2b67bda2021b 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -21,14 +21,14 @@ DEFINE_SPINLOCK(sysfs_symlink_target_lock);
void sysfs_warn_dup(struct kernfs_node *parent, const char *name)
{
- char *buf, *path = NULL;
+ char *buf;
buf = kzalloc(PATH_MAX, GFP_KERNEL);
if (buf)
- path = kernfs_path(parent, buf, PATH_MAX);
+ kernfs_path(parent, buf, PATH_MAX);
WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n",
- path, name);
+ buf, name);
kfree(buf);
}
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 984f73b719a9..5a9abdee43fe 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -541,7 +541,12 @@ static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf,
size_t buflen)
{
- return kernfs_path(cgrp->kn, buf, buflen);
+ int ret;
+
+ ret = kernfs_path(cgrp->kn, buf, buflen);
+ if (ret < 0 || ret >= buflen)
+ return NULL;
+ return buf;
}
static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 7d2efd2128bb..4a02b1b49821 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -272,7 +272,6 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen);
size_t kernfs_path_len(struct kernfs_node *kn);
int kernfs_path_from_node(struct kernfs_node *root_kn, struct kernfs_node *kn,
char *buf, size_t buflen);
-char *kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen);
void pr_cont_kernfs_name(struct kernfs_node *kn);
void pr_cont_kernfs_path(struct kernfs_node *kn);
struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn);
@@ -349,10 +348,6 @@ static inline int kernfs_path_from_node(struct kernfs_node *root_kn,
char *buf, size_t buflen)
{ return -ENOSYS; }
-static inline char *kernfs_path(struct kernfs_node *kn, char *buf,
- size_t buflen)
-{ return NULL; }
-
static inline void pr_cont_kernfs_name(struct kernfs_node *kn) { }
static inline void pr_cont_kernfs_path(struct kernfs_node *kn) { }
@@ -441,6 +436,22 @@ static inline void kernfs_init(void) { }
#endif /* CONFIG_KERNFS */
+/**
+ * kernfs_path - build full path of a given node
+ * @kn: kernfs_node of interest
+ * @buf: buffer to copy @kn's name into
+ * @buflen: size of @buf
+ *
+ * Builds and returns the full path of @kn in @buf of @buflen bytes. The
+ * path is built from the end of @buf so the returned pointer usually
+ * doesn't match @buf. If @buf isn't long enough, @buf is nul terminated
+ * and %NULL is returned.
+ */
+static inline int kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen)
+{
+ return kernfs_path_from_node(kn, NULL, buf, buflen);
+}
+
static inline struct kernfs_node *
kernfs_find_and_get(struct kernfs_node *kn, const char *name)
{