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authorLinus Torvalds <torvalds@linux-foundation.org>2013-04-09 12:22:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-09 12:22:49 -0700
commite8f2b548de7ae65e17ee911e54712a3f26f69c60 (patch)
tree0b332c254088effc61d832f9e95d65861251214e /fs
parent43ecdb0d31cf63d99d060af0585bf59be7fafcb2 (diff)
parente9c5d8a562f01b211926d70443378eb14b29a676 (diff)
downloadvexpress-lsk-e8f2b548de7ae65e17ee911e54712a3f26f69c60.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro: "A nasty bug in fs/namespace.c caught by Andrey + a couple of less serious unpleasantness - ecryptfs misc device playing hopeless games with try_module_get() and palinfo procfs support being... not quite correctly done, to be polite." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mnt: release locks on error path in do_loopback palinfo fixes procfs: add proc_remove_subtree() ecryptfs: close rmmod race
Diffstat (limited to 'fs')
-rw-r--r--fs/ecryptfs/miscdev.c14
-rw-r--r--fs/namespace.c2
-rw-r--r--fs/proc/generic.c119
3 files changed, 92 insertions, 43 deletions
diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 412e6eda25f..e4141f25749 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -80,13 +80,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
int rc;
mutex_lock(&ecryptfs_daemon_hash_mux);
- rc = try_module_get(THIS_MODULE);
- if (rc == 0) {
- rc = -EIO;
- printk(KERN_ERR "%s: Error attempting to increment module use "
- "count; rc = [%d]\n", __func__, rc);
- goto out_unlock_daemon_list;
- }
rc = ecryptfs_find_daemon_by_euid(&daemon);
if (!rc) {
rc = -EINVAL;
@@ -96,7 +89,7 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
if (rc) {
printk(KERN_ERR "%s: Error attempting to spawn daemon; "
"rc = [%d]\n", __func__, rc);
- goto out_module_put_unlock_daemon_list;
+ goto out_unlock_daemon_list;
}
mutex_lock(&daemon->mux);
if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
@@ -108,9 +101,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
atomic_inc(&ecryptfs_num_miscdev_opens);
out_unlock_daemon:
mutex_unlock(&daemon->mux);
-out_module_put_unlock_daemon_list:
- if (rc)
- module_put(THIS_MODULE);
out_unlock_daemon_list:
mutex_unlock(&ecryptfs_daemon_hash_mux);
return rc;
@@ -147,7 +137,6 @@ ecryptfs_miscdev_release(struct inode *inode, struct file *file)
"bug.\n", __func__, rc);
BUG();
}
- module_put(THIS_MODULE);
return rc;
}
@@ -471,6 +460,7 @@ out_free:
static const struct file_operations ecryptfs_miscdev_fops = {
+ .owner = THIS_MODULE,
.open = ecryptfs_miscdev_open,
.poll = ecryptfs_miscdev_poll,
.read = ecryptfs_miscdev_read,
diff --git a/fs/namespace.c b/fs/namespace.c
index d581e45c0a9..341d3f56408 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1690,7 +1690,7 @@ static int do_loopback(struct path *path, const char *old_name,
if (IS_ERR(mnt)) {
err = PTR_ERR(mnt);
- goto out;
+ goto out2;
}
err = graft_tree(mnt, path);
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 4b3b3ffb52f..21e1a8f1659 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);