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-rw-r--r--fs/namei.c98
1 files changed, 51 insertions, 47 deletions
diff --git a/fs/namei.c b/fs/namei.c
index ca814165d84c..bc35b02883bb 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -487,6 +487,19 @@ void path_put(const struct path *path)
}
EXPORT_SYMBOL(path_put);
+struct nameidata {
+ struct path path;
+ struct qstr last;
+ struct path root;
+ struct inode *inode; /* path.dentry.d_inode */
+ unsigned int flags;
+ unsigned seq, m_seq;
+ int last_type;
+ unsigned depth;
+ struct file *base;
+ char *saved_names[MAX_NESTED_LINKS + 1];
+};
+
/*
* Path walking has 2 modes, rcu-walk and ref-walk (see
* Documentation/filesystems/path-lookup.txt). In situations when we can't
@@ -695,6 +708,18 @@ void nd_jump_link(struct nameidata *nd, struct path *path)
nd->flags |= LOOKUP_JUMPED;
}
+void nd_set_link(struct nameidata *nd, char *path)
+{
+ nd->saved_names[nd->depth] = path;
+}
+EXPORT_SYMBOL(nd_set_link);
+
+char *nd_get_link(struct nameidata *nd)
+{
+ return nd->saved_names[nd->depth];
+}
+EXPORT_SYMBOL(nd_get_link);
+
static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
{
struct inode *inode = link->dentry->d_inode;
@@ -1821,13 +1846,14 @@ static int link_path_walk(const char *name, struct nameidata *nd)
}
static int path_init(int dfd, const char *name, unsigned int flags,
- struct nameidata *nd, struct file **fp)
+ struct nameidata *nd)
{
int retval = 0;
nd->last_type = LAST_ROOT; /* if there are only slashes... */
- nd->flags = flags | LOOKUP_JUMPED;
+ nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
nd->depth = 0;
+ nd->base = NULL;
if (flags & LOOKUP_ROOT) {
struct dentry *root = nd->root.dentry;
struct inode *inode = root->d_inode;
@@ -1847,7 +1873,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
} else {
path_get(&nd->path);
}
- return 0;
+ goto done;
}
nd->root.mnt = NULL;
@@ -1897,7 +1923,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
nd->path = f.file->f_path;
if (flags & LOOKUP_RCU) {
if (f.flags & FDPUT_FPUT)
- *fp = f.file;
+ nd->base = f.file;
nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
rcu_read_lock();
} else {
@@ -1908,13 +1934,26 @@ static int path_init(int dfd, const char *name, unsigned int flags,
nd->inode = nd->path.dentry->d_inode;
if (!(flags & LOOKUP_RCU))
- return 0;
+ goto done;
if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))
- return 0;
+ goto done;
if (!(nd->flags & LOOKUP_ROOT))
nd->root.mnt = NULL;
rcu_read_unlock();
return -ECHILD;
+done:
+ current->total_link_count = 0;
+ return link_path_walk(name, nd);
+}
+
+static void path_cleanup(struct nameidata *nd)
+{
+ if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
+ path_put(&nd->root);
+ nd->root.mnt = NULL;
+ }
+ if (unlikely(nd->base))
+ fput(nd->base);
}
static inline int lookup_last(struct nameidata *nd, struct path *path)
@@ -1930,7 +1969,6 @@ static inline int lookup_last(struct nameidata *nd, struct path *path)
static int path_lookupat(int dfd, const char *name,
unsigned int flags, struct nameidata *nd)
{
- struct file *base = NULL;
struct path path;
int err;
@@ -1948,14 +1986,7 @@ static int path_lookupat(int dfd, const char *name,
* be handled by restarting a traditional ref-walk (which will always
* be able to complete).
*/
- err = path_init(dfd, name, flags | LOOKUP_PARENT, nd, &base);
-
- if (unlikely(err))
- goto out;
-
- current->total_link_count = 0;
- err = link_path_walk(name, nd);
-
+ err = path_init(dfd, name, flags, nd);
if (!err && !(flags & LOOKUP_PARENT)) {
err = lookup_last(nd, &path);
while (err > 0) {
@@ -1983,14 +2014,7 @@ static int path_lookupat(int dfd, const char *name,
}
}
-out:
- if (base)
- fput(base);
-
- if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
- path_put(&nd->root);
- nd->root.mnt = NULL;
- }
+ path_cleanup(nd);
return err;
}
@@ -2297,19 +2321,13 @@ out:
static int
path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags)
{
- struct file *base = NULL;
struct nameidata nd;
int err;
- err = path_init(dfd, name, flags | LOOKUP_PARENT, &nd, &base);
+ err = path_init(dfd, name, flags, &nd);
if (unlikely(err))
goto out;
- current->total_link_count = 0;
- err = link_path_walk(name, &nd);
- if (err)
- goto out;
-
err = mountpoint_last(&nd, path);
while (err > 0) {
void *cookie;
@@ -2325,12 +2343,7 @@ path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags
put_link(&nd, &link, cookie);
}
out:
- if (base)
- fput(base);
-
- if (nd.root.mnt && !(nd.flags & LOOKUP_ROOT))
- path_put(&nd.root);
-
+ path_cleanup(&nd);
return err;
}
@@ -3181,7 +3194,6 @@ out:
static struct file *path_openat(int dfd, struct filename *pathname,
struct nameidata *nd, const struct open_flags *op, int flags)
{
- struct file *base = NULL;
struct file *file;
struct path path;
int opened = 0;
@@ -3198,12 +3210,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
goto out;
}
- error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base);
- if (unlikely(error))
- goto out;
-
- current->total_link_count = 0;
- error = link_path_walk(pathname->name, nd);
+ error = path_init(dfd, pathname->name, flags, nd);
if (unlikely(error))
goto out;
@@ -3229,10 +3236,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
put_link(nd, &link, cookie);
}
out:
- if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT))
- path_put(&nd->root);
- if (base)
- fput(base);
+ path_cleanup(nd);
if (!(opened & FILE_OPENED)) {
BUG_ON(!error);
put_filp(file);