diff options
| -rw-r--r-- | fs/kernfs/dir.c | 61 | ||||
| -rw-r--r-- | fs/sysfs/dir.c | 6 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 7 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 21 |
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) { |