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349 lines
8.2 KiB
349 lines
8.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#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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#include "nfs3_fs.h" |
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#define NFSDBG_FACILITY NFSDBG_PROC |
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/* |
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* nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for |
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* caching get_acl results in a race-free way. See fs/posix_acl.c:get_acl() |
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* for explanations. |
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*/ |
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static void nfs3_prepare_get_acl(struct posix_acl **p) |
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{ |
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struct posix_acl *sentinel = uncached_acl_sentinel(current); |
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if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) { |
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/* Not the first reader or sentinel already in place. */ |
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} |
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} |
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static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl) |
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{ |
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struct posix_acl *sentinel = uncached_acl_sentinel(current); |
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/* Only cache the ACL if our sentinel is still in place. */ |
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posix_acl_dup(acl); |
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if (cmpxchg(p, sentinel, acl) != sentinel) |
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posix_acl_release(acl); |
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} |
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static void nfs3_abort_get_acl(struct posix_acl **p) |
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{ |
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struct posix_acl *sentinel = uncached_acl_sentinel(current); |
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/* Remove our sentinel upon failure. */ |
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cmpxchg(p, sentinel, ACL_NOT_CACHED); |
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} |
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struct posix_acl *nfs3_get_acl(struct inode *inode, int type, bool rcu) |
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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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NULL, |
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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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int status, count; |
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if (rcu) |
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return ERR_PTR(-ECHILD); |
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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(inode, NFS_INO_INVALID_CHANGE); |
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if (status < 0) |
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return ERR_PTR(status); |
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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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if (args.mask & NFS_ACL) |
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nfs3_prepare_get_acl(&inode->i_acl); |
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if (args.mask & NFS_DFACL) |
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nfs3_prepare_get_acl(&inode->i_default_acl); |
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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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fallthrough; |
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case -ENOTSUPP: |
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status = -EOPNOTSUPP; |
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goto getout; |
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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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res.acl_access->a_count == 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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if (res.mask & NFS_ACL) |
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nfs3_complete_get_acl(&inode->i_acl, res.acl_access); |
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else |
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forget_cached_acl(inode, ACL_TYPE_ACCESS); |
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if (res.mask & NFS_DFACL) |
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nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default); |
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else |
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forget_cached_acl(inode, ACL_TYPE_DEFAULT); |
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nfs_free_fattr(res.fattr); |
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if (type == ACL_TYPE_ACCESS) { |
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posix_acl_release(res.acl_default); |
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return res.acl_access; |
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} else { |
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posix_acl_release(res.acl_access); |
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return res.acl_default; |
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} |
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getout: |
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nfs3_abort_get_acl(&inode->i_acl); |
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nfs3_abort_get_acl(&inode->i_default_acl); |
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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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return ERR_PTR(status); |
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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 = 0; |
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if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL)) |
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goto out; |
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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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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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fallthrough; |
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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_setacls(struct inode *inode, struct posix_acl *acl, |
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struct posix_acl *dfacl) |
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{ |
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int ret; |
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ret = __nfs3_proc_setacls(inode, acl, dfacl); |
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return (ret == -EOPNOTSUPP) ? 0 : ret; |
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} |
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int nfs3_set_acl(struct user_namespace *mnt_userns, struct inode *inode, |
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struct posix_acl *acl, int type) |
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{ |
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struct posix_acl *orig = acl, *dfacl = NULL, *alloc; |
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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 = get_acl(inode, ACL_TYPE_DEFAULT); |
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if (IS_ERR(alloc)) |
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goto fail; |
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dfacl = alloc; |
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break; |
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case ACL_TYPE_DEFAULT: |
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alloc = get_acl(inode, ACL_TYPE_ACCESS); |
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if (IS_ERR(alloc)) |
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goto fail; |
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dfacl = acl; |
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acl = alloc; |
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break; |
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} |
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} |
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if (acl == NULL) { |
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alloc = 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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acl = alloc; |
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} |
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status = __nfs3_proc_setacls(inode, acl, dfacl); |
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out: |
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if (acl != orig) |
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posix_acl_release(acl); |
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if (dfacl != orig) |
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posix_acl_release(dfacl); |
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return status; |
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fail: |
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status = PTR_ERR(alloc); |
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goto out; |
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} |
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const struct xattr_handler *nfs3_xattr_handlers[] = { |
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&posix_acl_access_xattr_handler, |
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&posix_acl_default_xattr_handler, |
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NULL, |
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}; |
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static int |
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nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data, |
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size_t size, ssize_t *result) |
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{ |
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struct posix_acl *acl; |
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char *p = data + *result; |
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acl = get_acl(inode, type); |
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if (IS_ERR_OR_NULL(acl)) |
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return 0; |
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posix_acl_release(acl); |
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*result += strlen(name); |
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*result += 1; |
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if (!size) |
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return 0; |
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if (*result > size) |
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return -ERANGE; |
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strcpy(p, name); |
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return 0; |
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} |
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ssize_t |
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nfs3_listxattr(struct dentry *dentry, char *data, size_t size) |
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{ |
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struct inode *inode = d_inode(dentry); |
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ssize_t result = 0; |
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int error; |
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error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS, |
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XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result); |
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if (error) |
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return error; |
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error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT, |
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XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result); |
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if (error) |
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return error; |
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return result; |
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}
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