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authorAl Viro <viro@zeniv.linux.org.uk>2013-03-30 20:13:46 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2013-04-09 14:09:17 -0400
commit8ce584c7416d8a85a6f3edc17d1cddefe331e87e (patch)
tree4fe64bd588ba8e2239cfa893e1bddb3e3b30c232 /fs
parent52f21999c7b921a0390708b66ed286282c2e4bee (diff)
procfs: add proc_remove_subtree()
just what it sounds like; do that only to procfs subtrees you've created - doing that to something shared with another driver is not only antisocial, but might cause interesting races with proc_create() and its ilk. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/proc/generic.c119
1 files changed, 89 insertions, 30 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 4b3b3ffb52f1..21e1a8f1659d 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -755,37 +755,8 @@ void pde_put(struct proc_dir_entry *pde)
free_proc_entry(pde);
}
-/*
- * Remove a /proc entry and free it if it's not currently in use.
- */
-void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+static void entry_rundown(struct proc_dir_entry *de)
{
- struct proc_dir_entry **p;
- struct proc_dir_entry *de = NULL;
- const char *fn = name;
- unsigned int len;
-
- spin_lock(&proc_subdir_lock);
- if (__xlate_proc_name(name, &parent, &fn) != 0) {
- spin_unlock(&proc_subdir_lock);
- return;
- }
- len = strlen(fn);
-
- for (p = &parent->subdir; *p; p=&(*p)->next ) {
- if (proc_match(len, fn, *p)) {
- de = *p;
- *p = de->next;
- de->next = NULL;
- break;
- }
- }
- spin_unlock(&proc_subdir_lock);
- if (!de) {
- WARN(1, "name '%s'\n", name);
- return;
- }
-
spin_lock(&de->pde_unload_lock);
/*
* Stop accepting new callers into module. If you're
@@ -817,6 +788,40 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
spin_lock(&de->pde_unload_lock);
}
spin_unlock(&de->pde_unload_lock);
+}
+
+/*
+ * Remove a /proc entry and free it if it's not currently in use.
+ */
+void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+{
+ struct proc_dir_entry **p;
+ struct proc_dir_entry *de = NULL;
+ const char *fn = name;
+ unsigned int len;
+
+ spin_lock(&proc_subdir_lock);
+ if (__xlate_proc_name(name, &parent, &fn) != 0) {
+ spin_unlock(&proc_subdir_lock);
+ return;
+ }
+ len = strlen(fn);
+
+ for (p = &parent->subdir; *p; p=&(*p)->next ) {
+ if (proc_match(len, fn, *p)) {
+ de = *p;
+ *p = de->next;
+ de->next = NULL;
+ break;
+ }
+ }
+ spin_unlock(&proc_subdir_lock);
+ if (!de) {
+ WARN(1, "name '%s'\n", name);
+ return;
+ }
+
+ entry_rundown(de);
if (S_ISDIR(de->mode))
parent->nlink--;
@@ -827,3 +832,57 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
pde_put(de);
}
EXPORT_SYMBOL(remove_proc_entry);
+
+int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
+{
+ struct proc_dir_entry **p;
+ struct proc_dir_entry *root = NULL, *de, *next;
+ const char *fn = name;
+ unsigned int len;
+
+ spin_lock(&proc_subdir_lock);
+ if (__xlate_proc_name(name, &parent, &fn) != 0) {
+ spin_unlock(&proc_subdir_lock);
+ return -ENOENT;
+ }
+ len = strlen(fn);
+
+ for (p = &parent->subdir; *p; p=&(*p)->next ) {
+ if (proc_match(len, fn, *p)) {
+ root = *p;
+ *p = root->next;
+ root->next = NULL;
+ break;
+ }
+ }
+ if (!root) {
+ spin_unlock(&proc_subdir_lock);
+ return -ENOENT;
+ }
+ de = root;
+ while (1) {
+ next = de->subdir;
+ if (next) {
+ de->subdir = next->next;
+ next->next = NULL;
+ de = next;
+ continue;
+ }
+ spin_unlock(&proc_subdir_lock);
+
+ entry_rundown(de);
+ next = de->parent;
+ if (S_ISDIR(de->mode))
+ next->nlink--;
+ de->nlink = 0;
+ if (de == root)
+ break;
+ pde_put(de);
+
+ spin_lock(&proc_subdir_lock);
+ de = next;
+ }
+ pde_put(root);
+ return 0;
+}
+EXPORT_SYMBOL(remove_proc_subtree);