Commit 463c3197 authored by Dave Hansen's avatar Dave Hansen Committed by Al Viro

[PATCH] r/o bind mounts: get callers of vfs_mknod/create/mkdir()

This takes care of all of the direct callers of vfs_mknod().
Since a few of these cases also handle normal file creation
as well, this also covers some calls to vfs_create().

So that we don't have to make three mnt_want/drop_write()
calls inside of the switch statement, we move some of its
logic outside of the switch and into a helper function
suggested by Christoph.

This also encapsulates a fix for mknod(S_IFREG) that Miklos
found.

[AV: merged mkdir handling, added missing nfsd pieces]
Acked-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 0622753b
......@@ -1984,6 +1984,23 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
return error;
}
static int may_mknod(mode_t mode)
{
switch (mode & S_IFMT) {
case S_IFREG:
case S_IFCHR:
case S_IFBLK:
case S_IFIFO:
case S_IFSOCK:
case 0: /* zero mode translates to S_IFREG */
return 0;
case S_IFDIR:
return -EPERM;
default:
return -EINVAL;
}
}
asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
unsigned dev)
{
......@@ -2002,12 +2019,19 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
if (error)
goto out;
dentry = lookup_create(&nd, 0);
error = PTR_ERR(dentry);
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
goto out_unlock;
}
if (!IS_POSIXACL(nd.path.dentry->d_inode))
mode &= ~current->fs->umask;
if (!IS_ERR(dentry)) {
switch (mode & S_IFMT) {
error = may_mknod(mode);
if (error)
goto out_dput;
error = mnt_want_write(nd.path.mnt);
if (error)
goto out_dput;
switch (mode & S_IFMT) {
case 0: case S_IFREG:
error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd);
break;
......@@ -2018,14 +2042,11 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
case S_IFIFO: case S_IFSOCK:
error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0);
break;
case S_IFDIR:
error = -EPERM;
break;
default:
error = -EINVAL;
}
dput(dentry);
}
mnt_drop_write(nd.path.mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
out:
......@@ -2083,7 +2104,12 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
if (!IS_POSIXACL(nd.path.dentry->d_inode))
mode &= ~current->fs->umask;
error = mnt_want_write(nd.path.mnt);
if (error)
goto out_dput;
error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
mnt_drop_write(nd.path.mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
......
......@@ -155,7 +155,11 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
goto out_put;
}
status = mnt_want_write(rec_dir.path.mnt);
if (status)
goto out_put;
status = vfs_mkdir(rec_dir.path.dentry->d_inode, dentry, S_IRWXU);
mnt_drop_write(rec_dir.path.mnt);
out_put:
dput(dentry);
out_unlock:
......
......@@ -1255,23 +1255,35 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
err = 0;
switch (type) {
case S_IFREG:
host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
if (host_err)
goto out_nfserr;
host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
break;
case S_IFDIR:
host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
if (host_err)
goto out_nfserr;
host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
break;
case S_IFCHR:
case S_IFBLK:
case S_IFIFO:
case S_IFSOCK:
host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
if (host_err)
goto out_nfserr;
host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
break;
default:
printk("nfsd: bad file type %o in nfsd_create\n", type);
host_err = -EINVAL;
goto out_nfserr;
}
if (host_err < 0)
if (host_err < 0) {
mnt_drop_write(fhp->fh_export->ex_path.mnt);
goto out_nfserr;
}
if (EX_ISSYNC(fhp->fh_export)) {
err = nfserrno(nfsd_sync_dir(dentry));
......@@ -1282,6 +1294,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
err2 = nfsd_create_setattr(rqstp, resfhp, iap);
if (err2)
err = err2;
mnt_drop_write(fhp->fh_export->ex_path.mnt);
/*
* Update the file handle to get the new inode info.
*/
......@@ -1359,6 +1372,9 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
v_atime = verifier[1]&0x7fffffff;
}
host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
if (host_err)
goto out_nfserr;
if (dchild->d_inode) {
err = 0;
......@@ -1390,12 +1406,15 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
case NFS3_CREATE_GUARDED:
err = nfserr_exist;
}
mnt_drop_write(fhp->fh_export->ex_path.mnt);
goto out;
}
host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
if (host_err < 0)
if (host_err < 0) {
mnt_drop_write(fhp->fh_export->ex_path.mnt);
goto out_nfserr;
}
if (created)
*created = 1;
......@@ -1420,6 +1439,7 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
if (err2)
err = err2;
mnt_drop_write(fhp->fh_export->ex_path.mnt);
/*
* Update the filehandle to get the new inode info.
*/
......
......@@ -819,7 +819,11 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
*/
mode = S_IFSOCK |
(SOCK_INODE(sock)->i_mode & ~current->fs->umask);
err = mnt_want_write(nd.path.mnt);
if (err)
goto out_mknod_dput;
err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
mnt_drop_write(nd.path.mnt);
if (err)
goto out_mknod_dput;
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
......
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