Any chance we can get this into mainline sooner rather than later?
Seems like we are moving towards returning paths instead of dentries
in the VFS in general.
-VAL
>From 8e9c99f674ac220bd6266b92fdb75bcde78bb6c1 Mon Sep 17 00:00:00 2001
From: Jan Blunck <[email protected]>
Date: Fri, 20 Mar 2009 19:41:49 -0700
This patch changes lookup_hash() into returning a struct path.
Signed-off-by: Jan Blunck <[email protected]>
Signed-off-by: Valerie Aurora <[email protected]>
Cc: Alexander Viro <[email protected]>
---
fs/namei.c | 115 ++++++++++++++++++++++++++++++-----------------------------
1 files changed, 58 insertions(+), 57 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index a38801d..d92b185 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1163,7 +1163,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
}
static struct dentry *__lookup_hash(struct qstr *name,
- struct dentry *base, struct nameidata *nd)
+ struct dentry *base, struct nameidata *nd)
{
struct dentry *dentry;
struct inode *inode;
@@ -1220,14 +1220,22 @@ out:
* 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)
{
int err;
err = exec_permission(nd->path.dentry->d_inode);
if (err)
- return ERR_PTR(err);
- return __lookup_hash(&nd->last, nd->path.dentry, nd);
+ return err;
+ path->mnt = nd->path.mnt;
+ path->dentry = __lookup_hash(name, nd->path.dentry, nd);
+ if (IS_ERR(path->dentry)) {
+ err = PTR_ERR(path->dentry);
+ path->dentry = NULL;
+ path->mnt = NULL;
+ }
+ return err;
}
static int __lookup_one_len(const char *name, struct qstr *this,
@@ -1721,12 +1729,10 @@ reval:
if (flag & O_EXCL)
nd.flags |= LOOKUP_EXCL;
mutex_lock(&dir->d_inode->i_mutex);
- path.dentry = lookup_hash(&nd);
- path.mnt = nd.path.mnt;
+ error = lookup_hash(&nd, &nd.last, &path);
do_last:
- error = PTR_ERR(path.dentry);
- if (IS_ERR(path.dentry)) {
+ if (error) {
mutex_unlock(&dir->d_inode->i_mutex);
goto exit;
}
@@ -1893,8 +1899,7 @@ do_link:
}
dir = nd.path.dentry;
mutex_lock(&dir->d_inode->i_mutex);
- path.dentry = lookup_hash(&nd);
- path.mnt = nd.path.mnt;
+ error = lookup_hash(&nd, &nd.last, &path);
__putname(nd.last.name);
goto do_last;
}
@@ -1928,7 +1933,8 @@ EXPORT_SYMBOL(filp_open);
*/
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);
/*
@@ -1936,7 +1942,7 @@ 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;
@@ -1944,11 +1950,11 @@ 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/
@@ -1957,15 +1963,14 @@ 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);
@@ -2202,7 +2207,7 @@ 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);
@@ -2224,21 +2229,20 @@ 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;
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:
@@ -2293,7 +2297,7 @@ 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;
@@ -2308,26 +2312,25 @@ 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 */
if (nd.last.name[nd.last.len])
goto slashes;
- inode = dentry->d_inode;
+ inode = path.dentry->d_inode;
if (inode)
atomic_inc(&inode->i_count);
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)
@@ -2338,8 +2341,8 @@ 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;
}
@@ -2677,7 +2680,7 @@ 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;
@@ -2711,16 +2714,15 @@ 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;
@@ -2729,32 +2731,31 @@ 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:
--
1.5.6.5