linux/fs/nfs/nfs3acl.c
Christoph Hellwig 013cdf1088 nfs: use generic posix ACL infrastructure for v3 Posix ACLs
This causes a small behaviour change in that we don't bother to set
ACLs on file creation if the mode bit can express the access permissions
fully, and thus behaving identical to local filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-26 08:26:20 -05:00

260 lines
6.1 KiB
C

#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/nfs.h>
#include <linux/nfs3.h>
#include <linux/nfs_fs.h>
#include <linux/posix_acl_xattr.h>
#include <linux/nfsacl.h>
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_PROC
struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
{
struct nfs_server *server = NFS_SERVER(inode);
struct page *pages[NFSACL_MAXPAGES] = { };
struct nfs3_getaclargs args = {
.fh = NFS_FH(inode),
/* The xdr layer may allocate pages here. */
.pages = pages,
};
struct nfs3_getaclres res = {
NULL,
};
struct rpc_message msg = {
.rpc_argp = &args,
.rpc_resp = &res,
};
int status, count;
if (!nfs_server_capable(inode, NFS_CAP_ACLS))
return ERR_PTR(-EOPNOTSUPP);
status = nfs_revalidate_inode(server, inode);
if (status < 0)
return ERR_PTR(status);
/*
* Only get the access acl when explicitly requested: We don't
* need it for access decisions, and only some applications use
* it. Applications which request the access acl first are not
* penalized from this optimization.
*/
if (type == ACL_TYPE_ACCESS)
args.mask |= NFS_ACLCNT|NFS_ACL;
if (S_ISDIR(inode->i_mode))
args.mask |= NFS_DFACLCNT|NFS_DFACL;
if (args.mask == 0)
return NULL;
dprintk("NFS call getacl\n");
msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
res.fattr = nfs_alloc_fattr();
if (res.fattr == NULL)
return ERR_PTR(-ENOMEM);
status = rpc_call_sync(server->client_acl, &msg, 0);
dprintk("NFS reply getacl: %d\n", status);
/* pages may have been allocated at the xdr layer. */
for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
__free_page(args.pages[count]);
switch (status) {
case 0:
status = nfs_refresh_inode(inode, res.fattr);
break;
case -EPFNOSUPPORT:
case -EPROTONOSUPPORT:
dprintk("NFS_V3_ACL extension not supported; disabling\n");
server->caps &= ~NFS_CAP_ACLS;
case -ENOTSUPP:
status = -EOPNOTSUPP;
default:
goto getout;
}
if ((args.mask & res.mask) != args.mask) {
status = -EIO;
goto getout;
}
if (res.acl_access != NULL) {
if (posix_acl_equiv_mode(res.acl_access, NULL) ||
res.acl_access->a_count == 0) {
posix_acl_release(res.acl_access);
res.acl_access = NULL;
}
}
if (res.mask & NFS_ACL)
set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
else
forget_cached_acl(inode, ACL_TYPE_ACCESS);
if (res.mask & NFS_DFACL)
set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
else
forget_cached_acl(inode, ACL_TYPE_DEFAULT);
nfs_free_fattr(res.fattr);
if (type == ACL_TYPE_ACCESS) {
posix_acl_release(res.acl_default);
return res.acl_access;
} else {
posix_acl_release(res.acl_access);
return res.acl_default;
}
getout:
posix_acl_release(res.acl_access);
posix_acl_release(res.acl_default);
nfs_free_fattr(res.fattr);
return ERR_PTR(status);
}
int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
struct posix_acl *dfacl)
{
struct nfs_server *server = NFS_SERVER(inode);
struct nfs_fattr *fattr;
struct page *pages[NFSACL_MAXPAGES];
struct nfs3_setaclargs args = {
.inode = inode,
.mask = NFS_ACL,
.acl_access = acl,
.pages = pages,
};
struct rpc_message msg = {
.rpc_argp = &args,
.rpc_resp = &fattr,
};
int status;
status = -EOPNOTSUPP;
if (!nfs_server_capable(inode, NFS_CAP_ACLS))
goto out;
/* We are doing this here because XDR marshalling does not
* return any results, it BUGs. */
status = -ENOSPC;
if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
goto out;
if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
goto out;
if (S_ISDIR(inode->i_mode)) {
args.mask |= NFS_DFACL;
args.acl_default = dfacl;
args.len = nfsacl_size(acl, dfacl);
} else
args.len = nfsacl_size(acl, NULL);
if (args.len > NFS_ACL_INLINE_BUFSIZE) {
unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
status = -ENOMEM;
do {
args.pages[args.npages] = alloc_page(GFP_KERNEL);
if (args.pages[args.npages] == NULL)
goto out_freepages;
args.npages++;
} while (args.npages < npages);
}
dprintk("NFS call setacl\n");
status = -ENOMEM;
fattr = nfs_alloc_fattr();
if (fattr == NULL)
goto out_freepages;
msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
msg.rpc_resp = fattr;
status = rpc_call_sync(server->client_acl, &msg, 0);
nfs_access_zap_cache(inode);
nfs_zap_acl_cache(inode);
dprintk("NFS reply setacl: %d\n", status);
switch (status) {
case 0:
status = nfs_refresh_inode(inode, fattr);
set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
break;
case -EPFNOSUPPORT:
case -EPROTONOSUPPORT:
dprintk("NFS_V3_ACL SETACL RPC not supported"
"(will not retry)\n");
server->caps &= ~NFS_CAP_ACLS;
case -ENOTSUPP:
status = -EOPNOTSUPP;
}
nfs_free_fattr(fattr);
out_freepages:
while (args.npages != 0) {
args.npages--;
__free_page(args.pages[args.npages]);
}
out:
return status;
}
int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
struct posix_acl *alloc = NULL, *dfacl = NULL;
int status;
if (S_ISDIR(inode->i_mode)) {
switch(type) {
case ACL_TYPE_ACCESS:
alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
if (IS_ERR(alloc))
goto fail;
break;
case ACL_TYPE_DEFAULT:
dfacl = acl;
alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(alloc))
goto fail;
break;
}
}
if (acl == NULL) {
alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
if (IS_ERR(alloc))
goto fail;
}
status = nfs3_proc_setacls(inode, acl, dfacl);
posix_acl_release(alloc);
return status;
fail:
return PTR_ERR(alloc);
}
int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
umode_t mode)
{
struct posix_acl *default_acl, *acl;
int error;
error = posix_acl_create(dir, &mode, &default_acl, &acl);
if (error)
return (error == -EOPNOTSUPP) ? 0 : error;
error = nfs3_proc_setacls(inode, acl, default_acl);
if (acl)
posix_acl_release(acl);
if (default_acl)
posix_acl_release(default_acl);
return error;
}
const struct xattr_handler *nfs3_xattr_handlers[] = {
&posix_acl_access_xattr_handler,
&posix_acl_default_xattr_handler,
NULL,
};