[RFC 08/10] Pass no NULL vfs_lookup to vfs_create

Andreas Gruenbacher
2007-08-08T17:22:35Z

[-- Attachment #1: vfs_create-nameidata.diff --]
[-- Type: text/plain, Size: 7865 bytes --]

Never pass a NULL vfs_lookup to vfs_create() or iop->create by creating
temporary vfs_lookup objects where needed. Remove the obsolete NULL
checks.

Signed-off-by: Andreas Gruenbacher <ag@bestbits.at>

---
fs/9p/vfs_inode.c | 4 ++--
fs/cifs/dir.c | 5 ++---
fs/nfsd/vfs.c | 36 +++++++++++++++++++++---------------
ipc/mqueue.c | 23 ++++++++++++++---------
4 files changed, 39 insertions(+), 29 deletions(-)

--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -478,7 +478,7 @@ v9fs_vfs_create(struct inode *dir, struc
fid = NULL;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode);
- if (lookup && lookup->flags & LOOKUP_OPEN)
+ if (lookup->flags & LOOKUP_OPEN)
flags = lookup->intent.open.flags - 1;
else
flags = O_RDWR;
@@ -492,7 +492,7 @@ v9fs_vfs_create(struct inode *dir, struc
}

/* if we are opening a file, assign the open fid to the file */
- if (lookup && lookup->flags & LOOKUP_OPEN) {
+ if (lookup->flags & LOOKUP_OPEN) {
filp = lookup_instantiate_filp(lookup, dentry,
v9fs_open_created);
if (IS_ERR(filp)) {
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -153,7 +153,7 @@ cifs_create(struct inode *inode, struct
return -ENOMEM;
}

- if (lookup && (lookup->flags & LOOKUP_OPEN)) {
+ if (lookup->flags & LOOKUP_OPEN) {
int oflags = lookup->intent.open.flags;

desiredAccess = 0;
@@ -263,8 +263,7 @@ cifs_create(struct inode *inode, struct
direntry->d_op = &cifs_dentry_ops;
d_instantiate(direntry, newinode);
}
- if ((!lookup /* nfsd case - nfs srv does not set lookup */) ||
- ((lookup->flags & LOOKUP_OPEN) == FALSE)) {
+ if (!(lookup->flags & LOOKUP_OPEN)) {
/* mknod case - do not leave file open */
CIFSSMBClose(xid, pTcon, fileHandle);
} else if (newinode) {
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1139,7 +1139,8 @@ nfsd_create(struct svc_rqst *rqstp, stru
char *fname, int flen, struct iattr *iap,
int type, dev_t rdev, struct svc_fh *resfhp)
{
- struct dentry *dentry, *dchild = NULL;
+ struct vfs_lookup lookup;
+ struct dentry *dchild = NULL;
struct inode *dirp;
__be32 err;
int host_err;
@@ -1155,8 +1156,10 @@ nfsd_create(struct svc_rqst *rqstp, stru
if (err)
goto out;

- dentry = fhp->fh_dentry;
- dirp = dentry->d_inode;
+ lookup.path.dentry = fhp->fh_dentry;
+ lookup.path.mnt = fhp->fh_export->ex_mnt;
+ lookup.flags = 0;
+ dirp = lookup.path.dentry->d_inode;

err = nfserr_notdir;
if(!dirp->i_op || !dirp->i_op->lookup)
@@ -1168,7 +1171,7 @@ nfsd_create(struct svc_rqst *rqstp, stru
if (!resfhp->fh_dentry) {
/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
fh_lock_nested(fhp, I_MUTEX_PARENT);
- dchild = lookup_one_len(fname, dentry, flen);
+ dchild = lookup_one_len(fname, lookup.path.dentry, flen);
host_err = PTR_ERR(dchild);
if (IS_ERR(dchild))
goto out_nfserr;
@@ -1182,8 +1185,8 @@ nfsd_create(struct svc_rqst *rqstp, stru
/* not actually possible */
printk(KERN_ERR
"nfsd_create: parent %s/%s not locked!\n",
- dentry->d_parent->d_name.name,
- dentry->d_name.name);
+ lookup.path.dentry->d_parent->d_name.name,
+ lookup.path.dentry->d_name.name);
err = nfserr_io;
goto out;
}
@@ -1194,7 +1197,7 @@ nfsd_create(struct svc_rqst *rqstp, stru
err = nfserr_exist;
if (dchild->d_inode) {
dprintk("nfsd_create: dentry %s/%s not negative!\n",
- dentry->d_name.name, dchild->d_name.name);
+ lookup.path.dentry->d_name.name, dchild->d_name.name);
goto out;
}

@@ -1208,7 +1211,7 @@ nfsd_create(struct svc_rqst *rqstp, stru
err = 0;
switch (type) {
case S_IFREG:
- host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
+ host_err = vfs_create(dirp, dchild, iap->ia_mode, &lookup);
break;
case S_IFDIR:
host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
@@ -1227,7 +1230,7 @@ nfsd_create(struct svc_rqst *rqstp, stru
goto out_nfserr;

if (EX_ISSYNC(fhp->fh_export)) {
- err = nfserrno(nfsd_sync_dir(dentry));
+ err = nfserrno(nfsd_sync_dir(lookup.path.dentry));
write_inode_now(dchild->d_inode, 1);
}

@@ -1267,7 +1270,8 @@ nfsd_create_v3(struct svc_rqst *rqstp, s
struct svc_fh *resfhp, int createmode, u32 *verifier,
int *truncp, int *created)
{
- struct dentry *dentry, *dchild = NULL;
+ struct vfs_lookup lookup;
+ struct dentry *dchild = NULL;
struct inode *dirp;
__be32 err;
int host_err;
@@ -1285,8 +1289,10 @@ nfsd_create_v3(struct svc_rqst *rqstp, s
if (err)
goto out;

- dentry = fhp->fh_dentry;
- dirp = dentry->d_inode;
+ lookup.path.dentry = fhp->fh_dentry;
+ lookup.path.mnt = fhp->fh_export->ex_mnt;
+ lookup.flags = 0;
+ dirp = lookup.path.dentry->d_inode;

/* Get all the sanity checks out of the way before
* we lock the parent. */
@@ -1298,7 +1304,7 @@ nfsd_create_v3(struct svc_rqst *rqstp, s
/*
* Compose the response file handle.
*/
- dchild = lookup_one_len(fname, dentry, flen);
+ dchild = lookup_one_len(fname, lookup.path.dentry, flen);
host_err = PTR_ERR(dchild);
if (IS_ERR(dchild))
goto out_nfserr;
@@ -1352,14 +1358,14 @@ nfsd_create_v3(struct svc_rqst *rqstp, s
goto out;
}

- host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
+ host_err = vfs_create(dirp, dchild, iap->ia_mode, &lookup);
if (host_err < 0)
goto out_nfserr;
if (created)
*created = 1;

if (EX_ISSYNC(fhp->fh_export)) {
- err = nfserrno(nfsd_sync_dir(dentry));
+ err = nfserrno(nfsd_sync_dir(lookup.path.dentry));
/* setattr will sync the child (or not) */
}

--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -599,9 +599,11 @@ static int mq_attr_ok(struct mq_attr *at
/*
* Invoked when creating a new queue via sys_mq_open
*/
-static struct file *do_create(struct dentry *dir, struct dentry *dentry,
- int oflag, mode_t mode, struct mq_attr __user *u_attr)
+static struct file *do_create(struct vfs_lookup *lookup, int oflag, mode_t mode,
+ struct mq_attr __user *u_attr)
{
+ struct dentry *dir = mqueue_mnt->mnt_root;
+ struct dentry *dentry = lookup->path.dentry;
struct mq_attr attr;
int ret;

@@ -617,7 +619,7 @@ static struct file *do_create(struct den
}

mode &= ~current->fs->umask;
- ret = vfs_create(dir->d_inode, dentry, mode, NULL);
+ ret = vfs_create(dir->d_inode, dentry, mode, lookup);
dentry->d_fsdata = NULL;
if (ret)
goto out;
@@ -631,10 +633,11 @@ out:
}

/* Opens existing queue */
-static struct file *do_open(struct dentry *dentry, int oflag)
+static struct file *do_open(struct vfs_lookup *lookup, int oflag)
{
static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
MAY_READ | MAY_WRITE };
+ struct dentry *dentry = lookup->path.dentry;

if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
dput(dentry);
@@ -654,6 +657,7 @@ static int oflag2acc[O_ACCMODE] = { MAY_
asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
struct mq_attr __user *u_attr)
{
+ struct vfs_lookup lookup;
struct dentry *dentry;
struct file *filp;
char *name;
@@ -676,7 +680,9 @@ asmlinkage long sys_mq_open(const char _
error = PTR_ERR(dentry);
goto out_err;
}
- mntget(mqueue_mnt);
+ lookup.path.mnt = mntget(mqueue_mnt);
+ lookup.path.dentry = dentry;
+ lookup.flags = 0;

if (oflag & O_CREAT) {
if (dentry->d_inode) { /* entry already exists */
@@ -684,17 +690,16 @@ asmlinkage long sys_mq_open(const char _
error = -EEXIST;
if (oflag & O_EXCL)
goto out;
- filp = do_open(dentry, oflag);
+ filp = do_open(&lookup, oflag);
} else {
- filp = do_create(mqueue_mnt->mnt_root, dentry,
- oflag, mode, u_attr);
+ filp = do_create(&lookup, oflag, mode, u_attr);
}
} else {
error = -ENOENT;
if (!dentry->d_inode)
goto out;
audit_inode(name, dentry->d_inode);
- filp = do_open(dentry, oflag);
+ filp = do_open(&lookup, oflag);
}

if (IS_ERR(filp)) {