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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c110
1 files changed, 57 insertions, 53 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 4c4f95ac8aa5..70580ab1445c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1416,21 +1416,28 @@ static void follow_mount(struct path *path)
}
}
+static int path_parent_directory(struct path *path)
+{
+ struct dentry *old = path->dentry;
+ /* rare case of legitimate dget_parent()... */
+ path->dentry = dget_parent(path->dentry);
+ dput(old);
+ if (unlikely(!path_connected(path)))
+ return -ENOENT;
+ return 0;
+}
+
static int follow_dotdot(struct nameidata *nd)
{
while(1) {
- struct dentry *old = nd->path.dentry;
-
if (nd->path.dentry == nd->root.dentry &&
nd->path.mnt == nd->root.mnt) {
break;
}
if (nd->path.dentry != nd->path.mnt->mnt_root) {
- /* rare case of legitimate dget_parent()... */
- nd->path.dentry = dget_parent(nd->path.dentry);
- dput(old);
- if (unlikely(!path_connected(&nd->path)))
- return -ENOENT;
+ int ret = path_parent_directory(&nd->path);
+ if (ret)
+ return ret;
break;
}
if (!follow_up(&nd->path))
@@ -2514,6 +2521,34 @@ struct dentry *lookup_one_len_unlocked(const char *name,
}
EXPORT_SYMBOL(lookup_one_len_unlocked);
+#ifdef CONFIG_UNIX98_PTYS
+int path_pts(struct path *path)
+{
+ /* Find something mounted on "pts" in the same directory as
+ * the input path.
+ */
+ struct dentry *child, *parent;
+ struct qstr this;
+ int ret;
+
+ ret = path_parent_directory(path);
+ if (ret)
+ return ret;
+
+ parent = path->dentry;
+ this.name = "pts";
+ this.len = 3;
+ child = d_hash_and_lookup(parent, &this);
+ if (!child)
+ return -ENOENT;
+
+ path->dentry = child;
+ dput(parent);
+ follow_mount(path);
+ return 0;
+}
+#endif
+
int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
struct path *path, int *empty)
{
@@ -2995,9 +3030,13 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
}
if (*opened & FILE_CREATED)
fsnotify_create(dir, dentry);
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- return 1;
+ if (unlikely(d_is_negative(dentry))) {
+ error = -ENOENT;
+ } else {
+ path->dentry = dentry;
+ path->mnt = nd->path.mnt;
+ return 1;
+ }
}
}
dput(dentry);
@@ -3166,9 +3205,7 @@ static int do_last(struct nameidata *nd,
int acc_mode = op->acc_mode;
unsigned seq;
struct inode *inode;
- struct path save_parent = { .dentry = NULL, .mnt = NULL };
struct path path;
- bool retried = false;
int error;
nd->flags &= ~LOOKUP_PARENT;
@@ -3211,7 +3248,6 @@ static int do_last(struct nameidata *nd,
return -EISDIR;
}
-retry_lookup:
if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
error = mnt_want_write(nd->path.mnt);
if (!error)
@@ -3263,6 +3299,10 @@ retry_lookup:
got_write = false;
}
+ error = follow_managed(&path, nd);
+ if (unlikely(error < 0))
+ return error;
+
if (unlikely(d_is_negative(path.dentry))) {
path_to_nameidata(&path, nd);
return -ENOENT;
@@ -3278,10 +3318,6 @@ retry_lookup:
return -EEXIST;
}
- error = follow_managed(&path, nd);
- if (unlikely(error < 0))
- return error;
-
seq = 0; /* out of RCU mode, so the value doesn't matter */
inode = d_backing_inode(path.dentry);
finish_lookup:
@@ -3292,23 +3328,14 @@ finish_lookup:
if (unlikely(error))
return error;
- if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
- path_to_nameidata(&path, nd);
- } else {
- save_parent.dentry = nd->path.dentry;
- save_parent.mnt = mntget(path.mnt);
- nd->path.dentry = path.dentry;
-
- }
+ path_to_nameidata(&path, nd);
nd->inode = inode;
nd->seq = seq;
/* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */
finish_open:
error = complete_walk(nd);
- if (error) {
- path_put(&save_parent);
+ if (error)
return error;
- }
audit_inode(nd->name, nd->path.dentry, 0);
error = -EISDIR;
if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
@@ -3331,13 +3358,9 @@ finish_open_created:
goto out;
BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
error = vfs_open(&nd->path, file, current_cred());
- if (!error) {
- *opened |= FILE_OPENED;
- } else {
- if (error == -EOPENSTALE)
- goto stale_open;
+ if (error)
goto out;
- }
+ *opened |= FILE_OPENED;
opened:
error = open_check_o_direct(file);
if (!error)
@@ -3353,26 +3376,7 @@ out:
}
if (got_write)
mnt_drop_write(nd->path.mnt);
- path_put(&save_parent);
return error;
-
-stale_open:
- /* If no saved parent or already retried then can't retry */
- if (!save_parent.dentry || retried)
- goto out;
-
- BUG_ON(save_parent.dentry != dir);
- path_put(&nd->path);
- nd->path = save_parent;
- nd->inode = dir->d_inode;
- save_parent.mnt = NULL;
- save_parent.dentry = NULL;
- if (got_write) {
- mnt_drop_write(nd->path.mnt);
- got_write = false;
- }
- retried = true;
- goto retry_lookup;
}
static int do_tmpfile(struct nameidata *nd, unsigned flags,