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![Chuck Lever](/assets/img/avatar_default.png)
nfsacl_encode() allocates memory in certain cases. This of course
is not guaranteed to work.
Since commit 9f06c719
"SUNRPC: New xdr_streams XDR encoder API", the
kernel's XDR encoders can't return a result indicating possibly a
failure, so a memory allocation failure in nfsacl_encode() has become
fatal (ie, the XDR code Oopses) in some cases.
However, the allocated memory is a tiny fixed amount, on the order
of 40-50 bytes. We can easily use a stack-allocated buffer for
this, with only a wee bit of nose-holding.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
444 lines
10 KiB
C
444 lines
10 KiB
C
#include <linux/fs.h>
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#include <linux/gfp.h>
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#include <linux/nfs.h>
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#include <linux/nfs3.h>
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#include <linux/nfs_fs.h>
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#include <linux/posix_acl_xattr.h>
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#include <linux/nfsacl.h>
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#include "internal.h"
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#define NFSDBG_FACILITY NFSDBG_PROC
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ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
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{
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struct inode *inode = dentry->d_inode;
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struct posix_acl *acl;
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int pos=0, len=0;
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# define output(s) do { \
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if (pos + sizeof(s) <= size) { \
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memcpy(buffer + pos, s, sizeof(s)); \
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pos += sizeof(s); \
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} \
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len += sizeof(s); \
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} while(0)
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acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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output("system.posix_acl_access");
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posix_acl_release(acl);
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}
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if (S_ISDIR(inode->i_mode)) {
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acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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output("system.posix_acl_default");
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posix_acl_release(acl);
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}
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}
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# undef output
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if (!buffer || len <= size)
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return len;
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return -ERANGE;
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}
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ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
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void *buffer, size_t size)
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{
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struct inode *inode = dentry->d_inode;
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struct posix_acl *acl;
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int type, error = 0;
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if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
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type = ACL_TYPE_ACCESS;
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else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
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type = ACL_TYPE_DEFAULT;
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else
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return -EOPNOTSUPP;
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acl = nfs3_proc_getacl(inode, type);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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else if (acl) {
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if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
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error = -ENODATA;
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else
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error = posix_acl_to_xattr(acl, buffer, size);
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posix_acl_release(acl);
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} else
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error = -ENODATA;
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return error;
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}
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int nfs3_setxattr(struct dentry *dentry, const char *name,
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const void *value, size_t size, int flags)
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{
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struct inode *inode = dentry->d_inode;
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struct posix_acl *acl;
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int type, error;
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if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
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type = ACL_TYPE_ACCESS;
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else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
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type = ACL_TYPE_DEFAULT;
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else
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return -EOPNOTSUPP;
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acl = posix_acl_from_xattr(value, size);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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error = nfs3_proc_setacl(inode, type, acl);
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posix_acl_release(acl);
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return error;
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}
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int nfs3_removexattr(struct dentry *dentry, const char *name)
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{
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struct inode *inode = dentry->d_inode;
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int type;
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if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
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type = ACL_TYPE_ACCESS;
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else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
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type = ACL_TYPE_DEFAULT;
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else
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return -EOPNOTSUPP;
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return nfs3_proc_setacl(inode, type, NULL);
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}
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static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
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{
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if (!IS_ERR(nfsi->acl_access)) {
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posix_acl_release(nfsi->acl_access);
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nfsi->acl_access = ERR_PTR(-EAGAIN);
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}
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if (!IS_ERR(nfsi->acl_default)) {
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posix_acl_release(nfsi->acl_default);
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nfsi->acl_default = ERR_PTR(-EAGAIN);
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}
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}
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void nfs3_forget_cached_acls(struct inode *inode)
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{
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dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
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inode->i_ino);
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spin_lock(&inode->i_lock);
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__nfs3_forget_cached_acls(NFS_I(inode));
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spin_unlock(&inode->i_lock);
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}
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static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
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{
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struct nfs_inode *nfsi = NFS_I(inode);
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struct posix_acl *acl = ERR_PTR(-EINVAL);
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spin_lock(&inode->i_lock);
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switch(type) {
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case ACL_TYPE_ACCESS:
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acl = nfsi->acl_access;
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break;
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case ACL_TYPE_DEFAULT:
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acl = nfsi->acl_default;
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break;
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default:
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goto out;
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}
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if (IS_ERR(acl))
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acl = ERR_PTR(-EAGAIN);
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else
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acl = posix_acl_dup(acl);
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out:
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spin_unlock(&inode->i_lock);
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dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
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inode->i_ino, type, acl);
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return acl;
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}
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static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
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struct posix_acl *dfacl)
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{
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struct nfs_inode *nfsi = NFS_I(inode);
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dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
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inode->i_ino, acl, dfacl);
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spin_lock(&inode->i_lock);
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__nfs3_forget_cached_acls(NFS_I(inode));
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if (!IS_ERR(acl))
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nfsi->acl_access = posix_acl_dup(acl);
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if (!IS_ERR(dfacl))
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nfsi->acl_default = posix_acl_dup(dfacl);
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spin_unlock(&inode->i_lock);
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}
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struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
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{
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struct nfs_server *server = NFS_SERVER(inode);
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struct page *pages[NFSACL_MAXPAGES] = { };
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struct nfs3_getaclargs args = {
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.fh = NFS_FH(inode),
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/* The xdr layer may allocate pages here. */
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.pages = pages,
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};
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struct nfs3_getaclres res = {
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0
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};
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struct rpc_message msg = {
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.rpc_argp = &args,
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.rpc_resp = &res,
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};
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struct posix_acl *acl;
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int status, count;
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if (!nfs_server_capable(inode, NFS_CAP_ACLS))
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return ERR_PTR(-EOPNOTSUPP);
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status = nfs_revalidate_inode(server, inode);
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if (status < 0)
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return ERR_PTR(status);
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acl = nfs3_get_cached_acl(inode, type);
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if (acl != ERR_PTR(-EAGAIN))
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return acl;
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acl = NULL;
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/*
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* Only get the access acl when explicitly requested: We don't
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* need it for access decisions, and only some applications use
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* it. Applications which request the access acl first are not
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* penalized from this optimization.
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*/
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if (type == ACL_TYPE_ACCESS)
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args.mask |= NFS_ACLCNT|NFS_ACL;
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if (S_ISDIR(inode->i_mode))
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args.mask |= NFS_DFACLCNT|NFS_DFACL;
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if (args.mask == 0)
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return NULL;
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dprintk("NFS call getacl\n");
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msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
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res.fattr = nfs_alloc_fattr();
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if (res.fattr == NULL)
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return ERR_PTR(-ENOMEM);
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status = rpc_call_sync(server->client_acl, &msg, 0);
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dprintk("NFS reply getacl: %d\n", status);
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/* pages may have been allocated at the xdr layer. */
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for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
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__free_page(args.pages[count]);
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switch (status) {
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case 0:
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status = nfs_refresh_inode(inode, res.fattr);
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break;
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case -EPFNOSUPPORT:
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case -EPROTONOSUPPORT:
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dprintk("NFS_V3_ACL extension not supported; disabling\n");
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server->caps &= ~NFS_CAP_ACLS;
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case -ENOTSUPP:
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status = -EOPNOTSUPP;
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default:
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goto getout;
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}
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if ((args.mask & res.mask) != args.mask) {
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status = -EIO;
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goto getout;
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}
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if (res.acl_access != NULL) {
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if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
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posix_acl_release(res.acl_access);
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res.acl_access = NULL;
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}
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}
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nfs3_cache_acls(inode,
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(res.mask & NFS_ACL) ? res.acl_access : ERR_PTR(-EINVAL),
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(res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
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switch(type) {
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case ACL_TYPE_ACCESS:
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acl = res.acl_access;
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res.acl_access = NULL;
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break;
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case ACL_TYPE_DEFAULT:
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acl = res.acl_default;
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res.acl_default = NULL;
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}
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getout:
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posix_acl_release(res.acl_access);
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posix_acl_release(res.acl_default);
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nfs_free_fattr(res.fattr);
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if (status != 0) {
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posix_acl_release(acl);
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acl = ERR_PTR(status);
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}
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return acl;
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}
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static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
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struct posix_acl *dfacl)
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{
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struct nfs_server *server = NFS_SERVER(inode);
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struct nfs_fattr *fattr;
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struct page *pages[NFSACL_MAXPAGES];
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struct nfs3_setaclargs args = {
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.inode = inode,
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.mask = NFS_ACL,
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.acl_access = acl,
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.pages = pages,
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};
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struct rpc_message msg = {
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.rpc_argp = &args,
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.rpc_resp = &fattr,
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};
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int status;
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status = -EOPNOTSUPP;
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if (!nfs_server_capable(inode, NFS_CAP_ACLS))
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goto out;
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/* We are doing this here because XDR marshalling does not
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* return any results, it BUGs. */
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status = -ENOSPC;
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if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
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goto out;
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if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
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goto out;
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if (S_ISDIR(inode->i_mode)) {
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args.mask |= NFS_DFACL;
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args.acl_default = dfacl;
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args.len = nfsacl_size(acl, dfacl);
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} else
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args.len = nfsacl_size(acl, NULL);
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if (args.len > NFS_ACL_INLINE_BUFSIZE) {
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unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
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status = -ENOMEM;
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do {
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args.pages[args.npages] = alloc_page(GFP_KERNEL);
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if (args.pages[args.npages] == NULL)
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goto out_freepages;
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args.npages++;
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} while (args.npages < npages);
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}
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dprintk("NFS call setacl\n");
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status = -ENOMEM;
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fattr = nfs_alloc_fattr();
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if (fattr == NULL)
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goto out_freepages;
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msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
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msg.rpc_resp = fattr;
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status = rpc_call_sync(server->client_acl, &msg, 0);
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nfs_access_zap_cache(inode);
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nfs_zap_acl_cache(inode);
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dprintk("NFS reply setacl: %d\n", status);
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switch (status) {
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case 0:
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status = nfs_refresh_inode(inode, fattr);
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nfs3_cache_acls(inode, acl, dfacl);
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break;
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case -EPFNOSUPPORT:
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case -EPROTONOSUPPORT:
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dprintk("NFS_V3_ACL SETACL RPC not supported"
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"(will not retry)\n");
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server->caps &= ~NFS_CAP_ACLS;
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case -ENOTSUPP:
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status = -EOPNOTSUPP;
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}
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nfs_free_fattr(fattr);
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out_freepages:
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while (args.npages != 0) {
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args.npages--;
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__free_page(args.pages[args.npages]);
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}
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out:
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return status;
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}
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int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
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{
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struct posix_acl *alloc = NULL, *dfacl = NULL;
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int status;
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if (S_ISDIR(inode->i_mode)) {
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switch(type) {
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case ACL_TYPE_ACCESS:
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alloc = dfacl = nfs3_proc_getacl(inode,
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ACL_TYPE_DEFAULT);
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if (IS_ERR(alloc))
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goto fail;
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break;
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case ACL_TYPE_DEFAULT:
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dfacl = acl;
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alloc = acl = nfs3_proc_getacl(inode,
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ACL_TYPE_ACCESS);
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if (IS_ERR(alloc))
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goto fail;
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break;
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default:
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return -EINVAL;
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}
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} else if (type != ACL_TYPE_ACCESS)
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return -EINVAL;
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if (acl == NULL) {
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alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
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if (IS_ERR(alloc))
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goto fail;
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}
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status = nfs3_proc_setacls(inode, acl, dfacl);
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posix_acl_release(alloc);
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return status;
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fail:
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return PTR_ERR(alloc);
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}
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int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
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mode_t mode)
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{
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struct posix_acl *dfacl, *acl;
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int error = 0;
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dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
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if (IS_ERR(dfacl)) {
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error = PTR_ERR(dfacl);
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return (error == -EOPNOTSUPP) ? 0 : error;
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}
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if (!dfacl)
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return 0;
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acl = posix_acl_clone(dfacl, GFP_KERNEL);
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error = -ENOMEM;
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if (!acl)
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goto out_release_dfacl;
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error = posix_acl_create_masq(acl, &mode);
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if (error < 0)
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goto out_release_acl;
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error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
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dfacl : NULL);
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out_release_acl:
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posix_acl_release(acl);
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out_release_dfacl:
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posix_acl_release(dfacl);
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return error;
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}
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