From: Jan Blunck <jblunck@xxxxxxx>
Signed-off-by: Jan Blunck <jblunck@xxxxxxx>
Signed-off-by: Valerie Aurora <vaurora@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 127 +++++++++++++++++++++++++++++++-----------------------------
1 files changed, 65 insertions(+), 62 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 9c4c331..272bead 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1694,9 +1694,20 @@ static struct dentry *__lookup_hash(struct qstr *name,
* needs parent already locked. Doesn't follow mounts.
* SMP-safe.
*/
-static struct dentry *lookup_hash(struct nameidata *nd)
+static int lookup_hash(struct nameidata *nd, struct qstr *name,
+ struct path *path)
{
- return __lookup_hash(&nd->last, nd->path.dentry, nd);
+ struct dentry *result;
+
+ result = __lookup_hash(name, nd->path.dentry, nd);
+ if (IS_ERR(result)) {
+ path->mnt = NULL;
+ path->dentry = NULL;
+ return PTR_ERR(result);
+ }
+ path->mnt = nd->path.mnt;
+ path->dentry = result;
+ return 0;
}
/**
@@ -2040,7 +2051,6 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
const struct open_flags *op, const char *pathname)
{
struct dentry *dir = nd->path.dentry;
- struct dentry *dentry;
int open_flag = op->open_flag;
int will_truncate = open_flag & O_TRUNC;
int want_write = 0;
@@ -2116,18 +2126,14 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
mutex_lock(&dir->d_inode->i_mutex);
- dentry = lookup_hash(nd);
- error = PTR_ERR(dentry);
- if (IS_ERR(dentry)) {
+ error = lookup_hash(nd, &nd->last, path);
+ if (error) {
mutex_unlock(&dir->d_inode->i_mutex);
goto exit;
}
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
-
/* Negative dentry, just create the file */
- if (!dentry->d_inode) {
+ if (!path->dentry->d_inode) {
int mode = op->mode;
if (!IS_POSIXACL(dir->d_inode))
mode &= ~current_umask();
@@ -2146,15 +2152,15 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
open_flag &= ~O_TRUNC;
will_truncate = 0;
acc_mode = MAY_OPEN;
- error = security_path_mknod(&nd->path, dentry, mode, 0);
+ error = security_path_mknod(&nd->path, path->dentry, mode, 0);
if (error)
goto exit_mutex_unlock;
- error = vfs_create(dir->d_inode, dentry, mode, nd);
+ error = vfs_create(dir->d_inode, path->dentry, mode, nd);
if (error)
goto exit_mutex_unlock;
mutex_unlock(&dir->d_inode->i_mutex);
dput(nd->path.dentry);
- nd->path.dentry = dentry;
+ nd->path.dentry = path->dentry;
goto common;
}
@@ -2332,11 +2338,13 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
* Simple function to lookup and return a dentry and create it
* if it doesn't exist. Is SMP-safe.
*
- * Returns with nd->path.dentry->d_inode->i_mutex locked.
+ * Returns with nd->path.dentry->d_inode->i_mutex locked, even in the case of
+ * an error.
*/
struct dentry *lookup_create(struct nameidata *nd, int is_dir)
{
- struct dentry *dentry = ERR_PTR(-EEXIST);
+ struct path path;
+ int err;
mutex_lock_nested(&nd->path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
/*
@@ -2344,7 +2352,7 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
* (foo/., foo/.., /////)
*/
if (nd->last_type != LAST_NORM)
- goto fail;
+ return ERR_PTR(-EEXIST);
nd->flags &= ~LOOKUP_PARENT;
nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL;
nd->intent.open.flags = O_EXCL;
@@ -2352,11 +2360,11 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
/*
* Do the final lookup.
*/
- dentry = lookup_hash(nd);
- if (IS_ERR(dentry))
- goto fail;
+ err = lookup_hash(nd, &nd->last, &path);
+ if (err)
+ return ERR_PTR(err);
- if (dentry->d_inode)
+ if (path.dentry->d_inode)
goto eexist;
/*
* Special case - lookup gave negative, but... we had foo/bar/
@@ -2365,15 +2373,14 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
* been asking for (non-existent) directory. -ENOENT for you.
*/
if (unlikely(!is_dir && nd->last.name[nd->last.len])) {
- dput(dentry);
- dentry = ERR_PTR(-ENOENT);
+ dput(path.dentry);
+ return ERR_PTR(-ENOENT);
}
- return dentry;
+
+ return path.dentry;
eexist:
- dput(dentry);
- dentry = ERR_PTR(-EEXIST);
-fail:
- return dentry;
+ path_put_conditional(&path, nd);
+ return ERR_PTR(-EEXIST);
}
EXPORT_SYMBOL_GPL(lookup_create);
@@ -2608,7 +2615,7 @@ static long do_rmdir(int dfd, const char __user *pathname)
{
int error = 0;
char * name;
- struct dentry *dentry;
+ struct path path;
struct nameidata nd;
error = user_path_parent(dfd, pathname, &nd, &name);
@@ -2630,25 +2637,24 @@ static long do_rmdir(int dfd, const char __user *pathname)
nd.flags &= ~LOOKUP_PARENT;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_hash(&nd);
- error = PTR_ERR(dentry);
- if (IS_ERR(dentry))
+ error = lookup_hash(&nd, &nd.last, &path);
+ if (error)
goto exit2;
- if (!dentry->d_inode) {
+ if (!path.dentry->d_inode) {
error = -ENOENT;
goto exit3;
}
error = mnt_want_write(nd.path.mnt);
if (error)
goto exit3;
- error = security_path_rmdir(&nd.path, dentry);
+ error = security_path_rmdir(&nd.path, path.dentry);
if (error)
goto exit4;
- error = vfs_rmdir(nd.path.dentry->d_inode, dentry);
+ error = vfs_rmdir(nd.path.dentry->d_inode, path.dentry);
exit4:
mnt_drop_write(nd.path.mnt);
exit3:
- dput(dentry);
+ path_put_conditional(&path, &nd);
exit2:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
exit1:
@@ -2704,7 +2710,7 @@ static long do_unlinkat(int dfd, const char __user *pathname)
{
int error;
char *name;
- struct dentry *dentry;
+ struct path path;
struct nameidata nd;
struct inode *inode = NULL;
@@ -2719,25 +2725,24 @@ static long do_unlinkat(int dfd, const char __user *pathname)
nd.flags &= ~LOOKUP_PARENT;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_hash(&nd);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
+ error = lookup_hash(&nd, &nd.last, &path);
+ if (!error) {
/* Why not before? Because we want correct error value */
- inode = dentry->d_inode;
+ inode = path.dentry->d_inode;
if (nd.last.name[nd.last.len] || !inode)
goto slashes;
ihold(inode);
error = mnt_want_write(nd.path.mnt);
if (error)
goto exit2;
- error = security_path_unlink(&nd.path, dentry);
+ error = security_path_unlink(&nd.path, path.dentry);
if (error)
goto exit3;
- error = vfs_unlink(nd.path.dentry->d_inode, dentry);
+ error = vfs_unlink(nd.path.dentry->d_inode, path.dentry);
exit3:
mnt_drop_write(nd.path.mnt);
exit2:
- dput(dentry);
+ path_put_conditional(&path, &nd);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
if (inode)
@@ -2748,8 +2753,8 @@ exit1:
return error;
slashes:
- error = !dentry->d_inode ? -ENOENT :
- S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
+ error = !path.dentry->d_inode ? -ENOENT :
+ S_ISDIR(path.dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
goto exit2;
}
@@ -3101,7 +3106,7 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
int, newdfd, const char __user *, newname)
{
struct dentry *old_dir, *new_dir;
- struct dentry *old_dentry, *new_dentry;
+ struct path old, new;
struct dentry *trap;
struct nameidata oldnd, newnd;
char *from;
@@ -3135,16 +3140,15 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
trap = lock_rename(new_dir, old_dir);
- old_dentry = lookup_hash(&oldnd);
- error = PTR_ERR(old_dentry);
- if (IS_ERR(old_dentry))
+ error = lookup_hash(&oldnd, &oldnd.last, &old);
+ if (error)
goto exit3;
/* source must exist */
error = -ENOENT;
- if (!old_dentry->d_inode)
+ if (!old.dentry->d_inode)
goto exit4;
/* unless the source is a directory trailing slashes give -ENOTDIR */
- if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
+ if (!S_ISDIR(old.dentry->d_inode->i_mode)) {
error = -ENOTDIR;
if (oldnd.last.name[oldnd.last.len])
goto exit4;
@@ -3153,32 +3157,31 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
}
/* source should not be ancestor of target */
error = -EINVAL;
- if (old_dentry == trap)
+ if (old.dentry == trap)
goto exit4;
- new_dentry = lookup_hash(&newnd);
- error = PTR_ERR(new_dentry);
- if (IS_ERR(new_dentry))
+ error = lookup_hash(&newnd, &newnd.last, &new);
+ if (error)
goto exit4;
/* target should not be an ancestor of source */
error = -ENOTEMPTY;
- if (new_dentry == trap)
+ if (new.dentry == trap)
goto exit5;
error = mnt_want_write(oldnd.path.mnt);
if (error)
goto exit5;
- error = security_path_rename(&oldnd.path, old_dentry,
- &newnd.path, new_dentry);
+ error = security_path_rename(&oldnd.path, old.dentry,
+ &newnd.path, new.dentry);
if (error)
goto exit6;
- error = vfs_rename(old_dir->d_inode, old_dentry,
- new_dir->d_inode, new_dentry);
+ error = vfs_rename(old_dir->d_inode, old.dentry,
+ new_dir->d_inode, new.dentry);
exit6:
mnt_drop_write(oldnd.path.mnt);
exit5:
- dput(new_dentry);
+ path_put_conditional(&new, &newnd);
exit4:
- dput(old_dentry);
+ path_put_conditional(&old, &oldnd);
exit3:
unlock_rename(new_dir, old_dir);
exit2:
--
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