diff options
Diffstat (limited to 'fs/nfs_common/nfsacl.c')
| -rw-r--r-- | fs/nfs_common/nfsacl.c | 54 |
1 files changed, 41 insertions, 13 deletions
diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c index fc1c52571c03..84c27d69d421 100644 --- a/fs/nfs_common/nfsacl.c +++ b/fs/nfs_common/nfsacl.c @@ -42,6 +42,11 @@ struct nfsacl_encode_desc { gid_t gid; }; +struct nfsacl_simple_acl { + struct posix_acl acl; + struct posix_acl_entry ace[4]; +}; + static int xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem) { @@ -72,9 +77,20 @@ xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem) return 0; } -unsigned int -nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, - struct posix_acl *acl, int encode_entries, int typeflag) +/** + * nfsacl_encode - Encode an NFSv3 ACL + * + * @buf: destination xdr_buf to contain XDR encoded ACL + * @base: byte offset in xdr_buf where XDR'd ACL begins + * @inode: inode of file whose ACL this is + * @acl: posix_acl to encode + * @encode_entries: whether to encode ACEs as well + * @typeflag: ACL type: NFS_ACL_DEFAULT or zero + * + * Returns size of encoded ACL in bytes or a negative errno value. + */ +int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, + struct posix_acl *acl, int encode_entries, int typeflag) { int entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0; struct nfsacl_encode_desc nfsacl_desc = { @@ -88,17 +104,22 @@ nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, .uid = inode->i_uid, .gid = inode->i_gid, }; + struct nfsacl_simple_acl aclbuf; int err; - struct posix_acl *acl2 = NULL; if (entries > NFS_ACL_MAX_ENTRIES || xdr_encode_word(buf, base, entries)) return -EINVAL; if (encode_entries && acl && acl->a_count == 3) { - /* Fake up an ACL_MASK entry. */ - acl2 = posix_acl_alloc(4, GFP_KERNEL); - if (!acl2) - return -ENOMEM; + struct posix_acl *acl2 = &aclbuf.acl; + + /* Avoid the use of posix_acl_alloc(). nfsacl_encode() is + * invoked in contexts where a memory allocation failure is + * fatal. Fortunately this fake ACL is small enough to + * construct on the stack. */ + memset(acl2, 0, sizeof(acl2)); + posix_acl_init(acl2, 4); + /* Insert entries in canonical order: other orders seem to confuse Solaris VxFS. */ acl2->a_entries[0] = acl->a_entries[0]; /* ACL_USER_OBJ */ @@ -109,8 +130,6 @@ nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, nfsacl_desc.acl = acl2; } err = xdr_encode_array2(buf, base + 4, &nfsacl_desc.desc); - if (acl2) - posix_acl_release(acl2); if (!err) err = 8 + nfsacl_desc.desc.elem_size * nfsacl_desc.desc.array_len; @@ -224,9 +243,18 @@ posix_acl_from_nfsacl(struct posix_acl *acl) return 0; } -unsigned int -nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, - struct posix_acl **pacl) +/** + * nfsacl_decode - Decode an NFSv3 ACL + * + * @buf: xdr_buf containing XDR'd ACL data to decode + * @base: byte offset in xdr_buf where XDR'd ACL begins + * @aclcnt: count of ACEs in decoded posix_acl + * @pacl: buffer in which to place decoded posix_acl + * + * Returns the length of the decoded ACL in bytes, or a negative errno value. + */ +int nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, + struct posix_acl **pacl) { struct nfsacl_decode_desc nfsacl_desc = { .desc = { |