> On Apr 24, 2015, at 7:04 AM, Andreas Gruenbacher 
> <[email protected]> wrote:
> 
> Changes nfs to support the "system.richacl" xattr instead of 
> "system.nfs4_acl".
> 
> The "system.nfs4_acl" xattr nfs uses directly exposes the on-the-wire format 
> of
> NFSv4's acl attribute to user space. This has at least two downsides: (1) the
> format is different from other file systems, so user-space code needs to be 
> nfs
> filesystem aware; (2) when symbolic user@domain and group@domain names are 
> used
> in the acl, user-space needs to perform ID mapping in the same way as the
> kernel.
> 
> Previously, when user-space requested only the length of the "system.nfs4_acl"
> attribute, nfs didn't need to retrieve the entire "system.nfs4_acl" attribute;
> retrieving its length was enough.  With the "system.richacl" xattr, the length
> of "system.richacl" cannot be computed from the length of the NFSv4 acl
> attribute, so we always need to retrieve and cache the acl even when 
> user-space
> only asks for the length of the "system.richacl" attribute.
> 
> Because the nfs client now knows which kind of acl the user is trying to set,
> it will now no longer sends acls with deny entries to servers which didn't
> declare support for that feature.  The maximum supported size of the NFSv4 acl
> attribute is now hard coded in the client code and no longer depends on the
> size of the buffer the user provides to the getxattr system call.  When an acl
> exceeds this limit, getxattr fails with errno set to ENOMEM.
> 
> Signed-off-by: Andreas Gruenbacher <[email protected]>
> ---
> fs/nfs/inode.c            |   3 -
> fs/nfs/nfs4proc.c         | 354 ++++++++++++++++++++--------------------------
> fs/nfs/nfs4xdr.c          | 224 +++++++++++++++++++++++++----
> fs/nfs/super.c            |   4 +-
> include/linux/nfs_fs.h    |   1 -
> include/linux/nfs_fs_sb.h |   2 +
> include/linux/nfs_xdr.h   |   8 +-
> 7 files changed, 357 insertions(+), 239 deletions(-)
> 
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index d42dff6..e67f72e 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -1824,9 +1824,6 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
>               return NULL;
>       nfsi->flags = 0UL;
>       nfsi->cache_validity = 0UL;
> -#if IS_ENABLED(CONFIG_NFS_V4)
> -     nfsi->nfs4_acl = NULL;
> -#endif /* CONFIG_NFS_V4 */
>       return &nfsi->vfs_inode;
> }
> EXPORT_SYMBOL_GPL(nfs_alloc_inode);
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 8c50670..c2ba4f0 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -55,6 +55,8 @@
> #include <linux/xattr.h>
> #include <linux/utsname.h>
> #include <linux/freezer.h>
> +#include <linux/richacl.h>
> +#include <linux/richacl_xattr.h>
> 
> #include "nfs4_fs.h"
> #include "delegation.h"
> @@ -2892,15 +2894,18 @@ static int _nfs4_server_capabilities(struct 
> nfs_server *server, struct nfs_fh *f
>                       res.attr_bitmask[2] &= FATTR4_WORD2_NFS42_MASK;
>               }
>               memcpy(server->attr_bitmask, res.attr_bitmask, 
> sizeof(server->attr_bitmask));
> -             server->caps &= ~(NFS_CAP_ACLS|NFS_CAP_HARDLINKS|
> -                             NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
> +             server->caps &= ~(NFS_CAP_ALLOW_ACLS|NFS_CAP_DENY_ACLS|
> +                             
> NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
>                               NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|
>                               NFS_CAP_OWNER_GROUP|NFS_CAP_ATIME|
>                               NFS_CAP_CTIME|NFS_CAP_MTIME|
>                               NFS_CAP_SECURITY_LABEL);
> -             if (res.attr_bitmask[0] & FATTR4_WORD0_ACL &&
> -                             res.acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
> -                     server->caps |= NFS_CAP_ACLS;
> +             if (res.attr_bitmask[0] & FATTR4_WORD0_ACL) {
> +                     if (res.acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
> +                             server->caps |= NFS_CAP_ALLOW_ACLS;
> +                     if (res.acl_bitmask & ACL4_SUPPORT_DENY_ACL)
> +                             server->caps |= NFS_CAP_DENY_ACLS;
> +             }
>               if (res.has_links != 0)
>                       server->caps |= NFS_CAP_HARDLINKS;
>               if (res.has_symlinks != 0)
> @@ -4428,45 +4433,11 @@ static int nfs4_proc_renew(struct nfs_client *clp, 
> struct rpc_cred *cred)
>       return 0;
> }
> 
> -static inline int nfs4_server_supports_acls(struct nfs_server *server)
> -{
> -     return server->caps & NFS_CAP_ACLS;
> -}
> -
> -/* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_SIZE, and that
> - * it's OK to put sizeof(void) * (XATTR_SIZE_MAX/PAGE_SIZE) bytes on
> - * the stack.
> +/* A arbitrary limit; we allocate at most DIV_ROUND_UP(NFS4ACL_SIZE_MAX,
> + * PAGE_SIZE) pages and put an array of DIV_ROUND_UP(NFS4ACL_SIZE_MAX,
> + * PAGE_SIZE) pages on the stack when encoding or decoding acls.
>  */
> -#define NFS4ACL_MAXPAGES DIV_ROUND_UP(XATTR_SIZE_MAX, PAGE_SIZE)
> -
> -static int buf_to_pages_noslab(const void *buf, size_t buflen,
> -             struct page **pages)
> -{
> -     struct page *newpage, **spages;
> -     int rc = 0;
> -     size_t len;
> -     spages = pages;
> -
> -     do {
> -             len = min_t(size_t, PAGE_SIZE, buflen);
> -             newpage = alloc_page(GFP_KERNEL);
> -
> -             if (newpage == NULL)
> -                     goto unwind;
> -             memcpy(page_address(newpage), buf, len);
> -                buf += len;
> -                buflen -= len;
> -             *pages++ = newpage;
> -             rc++;
> -     } while (buflen != 0);
> -
> -     return rc;
> -
> -unwind:
> -     for(; rc > 0; rc--)
> -             __free_page(spages[rc-1]);
> -     return -ENOMEM;
> -}
> +#define NFS4ACL_SIZE_MAX 65536
> 
> struct nfs4_cached_acl {
>       int cached;
> @@ -4474,66 +4445,9 @@ struct nfs4_cached_acl {
>       char data[0];
> };
> 
> -static void nfs4_set_cached_acl(struct inode *inode, struct nfs4_cached_acl 
> *acl)
> -{
> -     struct nfs_inode *nfsi = NFS_I(inode);
> -
> -     spin_lock(&inode->i_lock);
> -     kfree(nfsi->nfs4_acl);
> -     nfsi->nfs4_acl = acl;
> -     spin_unlock(&inode->i_lock);
> -}
> -
> static void nfs4_zap_acl_attr(struct inode *inode)
> {
> -     nfs4_set_cached_acl(inode, NULL);
> -}
> -
> -static inline ssize_t nfs4_read_cached_acl(struct inode *inode, char *buf, 
> size_t buflen)
> -{
> -     struct nfs_inode *nfsi = NFS_I(inode);
> -     struct nfs4_cached_acl *acl;
> -     int ret = -ENOENT;
> -
> -     spin_lock(&inode->i_lock);
> -     acl = nfsi->nfs4_acl;
> -     if (acl == NULL)
> -             goto out;
> -     if (buf == NULL) /* user is just asking for length */
> -             goto out_len;
> -     if (acl->cached == 0)
> -             goto out;
> -     ret = -ERANGE; /* see getxattr(2) man page */
> -     if (acl->len > buflen)
> -             goto out;
> -     memcpy(buf, acl->data, acl->len);
> -out_len:
> -     ret = acl->len;
> -out:
> -     spin_unlock(&inode->i_lock);
> -     return ret;
> -}
> -
> -static void nfs4_write_cached_acl(struct inode *inode, struct page **pages, 
> size_t pgbase, size_t acl_len)
> -{
> -     struct nfs4_cached_acl *acl;
> -     size_t buflen = sizeof(*acl) + acl_len;
> -
> -     if (buflen <= PAGE_SIZE) {
> -             acl = kmalloc(buflen, GFP_KERNEL);
> -             if (acl == NULL)
> -                     goto out;
> -             acl->cached = 1;
> -             _copy_from_pages(acl->data, pages, pgbase, acl_len);
> -     } else {
> -             acl = kmalloc(sizeof(*acl), GFP_KERNEL);
> -             if (acl == NULL)
> -                     goto out;
> -             acl->cached = 0;
> -     }
> -     acl->len = acl_len;
> -out:
> -     nfs4_set_cached_acl(inode, acl);
> +     forget_cached_richacl(inode);
> }
> 
> /*
> @@ -4546,121 +4460,128 @@ out:
>  * length. The next getxattr call will then produce another round trip to
>  * the server, this time with the input buf of the required size.
>  */
> -static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, 
> size_t buflen)
> +static struct richacl *__nfs4_get_acl_uncached(struct inode *inode)
> {
> -     struct page *pages[NFS4ACL_MAXPAGES] = {NULL, };
> +     struct nfs_server *server = NFS_SERVER(inode);
> +     struct page *pages[DIV_ROUND_UP(NFS4ACL_SIZE_MAX, PAGE_SIZE)] = {};
>       struct nfs_getaclargs args = {
>               .fh = NFS_FH(inode),
>               .acl_pages = pages,
> -             .acl_len = buflen,
> +             .acl_len = ARRAY_SIZE(pages) * PAGE_SIZE,
>       };
>       struct nfs_getaclres res = {
> -             .acl_len = buflen,
> +             .server = server,
>       };
>       struct rpc_message msg = {
>               .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL],
>               .rpc_argp = &args,
>               .rpc_resp = &res,
>       };
> -     unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE);
> -     int ret = -ENOMEM, i;
> +     mode_t mode;
> +     int err, i;
> 
> -     /* As long as we're doing a round trip to the server anyway,
> -      * let's be prepared for a page of acl data. */
> -     if (npages == 0)
> -             npages = 1;
> -     if (npages > ARRAY_SIZE(pages))
> -             return -ERANGE;
> -
> -     for (i = 0; i < npages; i++) {
> -             pages[i] = alloc_page(GFP_KERNEL);
> -             if (!pages[i])
> +     if (ARRAY_SIZE(pages) > 1) {
> +             /* for decoding across pages */
> +             res.acl_scratch = alloc_page(GFP_KERNEL);
> +             err = -ENOMEM;
> +             if (!res.acl_scratch)
>                       goto out_free;
>       }
> 
> -     /* for decoding across pages */
> -     res.acl_scratch = alloc_page(GFP_KERNEL);
> -     if (!res.acl_scratch)
> -             goto out_free;
> -
> -     args.acl_len = npages * PAGE_SIZE;
> -
> -     dprintk("%s  buf %p buflen %zu npages %d args.acl_len %zu\n",
> -             __func__, buf, buflen, npages, args.acl_len);
> -     ret = nfs4_call_sync(NFS_SERVER(inode)->client, NFS_SERVER(inode),
> +     dprintk("%s  args.acl_len %zu\n",
> +             __func__, args.acl_len);
> +     err = nfs4_call_sync(NFS_SERVER(inode)->client, NFS_SERVER(inode),
>                            &msg, &args.seq_args, &res.seq_res, 0);
> -     if (ret)
> +     if (err)
>               goto out_free;
> 
> -     /* Handle the case where the passed-in buffer is too short */
> -     if (res.acl_flags & NFS4_ACL_TRUNC) {
> -             /* Did the user only issue a request for the acl length? */
> -             if (buf == NULL)
> -                     goto out_ok;
> -             ret = -ERANGE;
> -             goto out_free;
> -     }
> -     nfs4_write_cached_acl(inode, pages, res.acl_data_offset, res.acl_len);
> -     if (buf) {
> -             if (res.acl_len > buflen) {
> -                     ret = -ERANGE;
> -                     goto out_free;
> -             }
> -             _copy_from_pages(buf, pages, res.acl_data_offset, res.acl_len);
> -     }
> -out_ok:
> -     ret = res.acl_len;
> +     mode = inode->i_mode & S_IFMT;
> +     if (__richacl_equiv_mode(res.acl, &mode) == 0 &&
> +         ((mode ^ res.mode) & S_IRWXUGO) == 0) {
> +             richacl_put(res.acl);
> +             res.acl = NULL;
> +     } else
> +             richacl_compute_max_masks(res.acl);
> +     /* FIXME: Set inode->i_mode from res->mode?  */
> +     set_cached_richacl(inode, res.acl);
> +     err = 0;
> +
> out_free:
> -     for (i = 0; i < npages; i++)
> -             if (pages[i])
> -                     __free_page(pages[i]);
> +     if (err) {
> +             richacl_put(res.acl);
> +             res.acl = ERR_PTR(err);
> +     }
> +     for (i = 0; i < ARRAY_SIZE(pages) && pages[i]; i++)
> +             __free_page(pages[i]);
>       if (res.acl_scratch)
>               __free_page(res.acl_scratch);
> -     return ret;
> +     return res.acl;
> }
> 
> -static ssize_t nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t 
> buflen)
> +static struct richacl *nfs4_get_acl_uncached(struct inode *inode)
> {
>       struct nfs4_exception exception = { };
> -     ssize_t ret;
> +     struct richacl *acl;
>       do {
> -             ret = __nfs4_get_acl_uncached(inode, buf, buflen);
> -             trace_nfs4_get_acl(inode, ret);
> -             if (ret >= 0)
> +             acl = __nfs4_get_acl_uncached(inode);
> +             trace_nfs4_get_acl(inode, IS_ERR(acl) ? PTR_ERR(acl) : 0);
> +             if (!IS_ERR(acl))
>                       break;
> -             ret = nfs4_handle_exception(NFS_SERVER(inode), ret, &exception);
> +             acl = ERR_PTR(nfs4_handle_exception(NFS_SERVER(inode), 
> PTR_ERR(acl), &exception));
>       } while (exception.retry);
> -     return ret;
> +     return acl;
> }
> 
> -static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t 
> buflen)
> +static struct richacl *nfs4_proc_get_acl(struct inode *inode)
> {
>       struct nfs_server *server = NFS_SERVER(inode);
> +     struct richacl *acl;
>       int ret;
> 
> -     if (!nfs4_server_supports_acls(server))
> -             return -EOPNOTSUPP;
> +     if (!(server->caps & (NFS_CAP_ALLOW_ACLS | NFS_CAP_DENY_ACLS)))
> +             return ERR_PTR(-EOPNOTSUPP);
>       ret = nfs_revalidate_inode(server, inode);
>       if (ret < 0)
> -             return ret;
> +             return ERR_PTR(ret);
>       if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
>               nfs_zap_acl_cache(inode);
> -     ret = nfs4_read_cached_acl(inode, buf, buflen);
> -     if (ret != -ENOENT)
> -             /* -ENOENT is returned if there is no ACL or if there is an ACL
> -              * but no cached acl data, just the acl length */
> -             return ret;
> -     return nfs4_get_acl_uncached(inode, buf, buflen);
> +     acl = get_cached_richacl(inode);
> +     if (acl != ACL_NOT_CACHED)
> +             return acl;
> +     return nfs4_get_acl_uncached(inode);
> +}
> +
> +static int
> +richacl_supported(struct nfs_server *server, struct richacl *acl)
> +{
> +     struct richace *ace;
> +
> +     if (!(server->caps & (NFS_CAP_ALLOW_ACLS | NFS_CAP_DENY_ACLS)))
> +             return -EOPNOTSUPP;
> +
> +     richacl_for_each_entry(ace, acl) {
> +             if (richace_is_allow(ace)) {
> +                     if (!(server->caps & NFS_CAP_ALLOW_ACLS))
> +                             return -EINVAL;
> +             } else if (richace_is_deny(ace)) {
> +                     if (!(server->caps & NFS_CAP_DENY_ACLS))
> +                             return -EINVAL;
> +             } else
> +                     return -EINVAL;
> +     }
> +     return 0;
> }
> 
> -static int __nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t 
> buflen)
> +static int __nfs4_proc_set_acl(struct inode *inode, struct richacl *acl)
> {
>       struct nfs_server *server = NFS_SERVER(inode);
> -     struct page *pages[NFS4ACL_MAXPAGES];
> +     struct page *pages[DIV_ROUND_UP(NFS4ACL_SIZE_MAX, PAGE_SIZE) + 1 /* 
> scratch */] = {};
>       struct nfs_setaclargs arg = {
> +             .server         = server,
>               .fh             = NFS_FH(inode),
> +             .acl            = acl,
>               .acl_pages      = pages,
> -             .acl_len        = buflen,
> +             .acl_len        = ARRAY_SIZE(pages) * PAGE_SIZE,
>       };
>       struct nfs_setaclres res;
>       struct rpc_message msg = {
> @@ -4668,16 +4589,12 @@ static int __nfs4_proc_set_acl(struct inode *inode, 
> const void *buf, size_t bufl
>               .rpc_argp       = &arg,
>               .rpc_resp       = &res,
>       };
> -     unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE);
>       int ret, i;
> 
> -     if (!nfs4_server_supports_acls(server))
> -             return -EOPNOTSUPP;
> -     if (npages > ARRAY_SIZE(pages))
> -             return -ERANGE;
> -     i = buf_to_pages_noslab(buf, buflen, arg.acl_pages);
> -     if (i < 0)
> -             return i;
> +     ret = richacl_supported(server, acl);
> +     if (ret)
> +             return ret;
> +
>       nfs4_inode_return_delegation(inode);
>       ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, 
> &res.seq_res, 1);
> 
> @@ -4685,8 +4602,8 @@ static int __nfs4_proc_set_acl(struct inode *inode, 
> const void *buf, size_t bufl
>        * Free each page after tx, so the only ref left is
>        * held by the network stack
>        */
> -     for (; i > 0; i--)
> -             put_page(pages[i-1]);
> +     for (i = 0; pages[i]; i++)
> +             put_page(pages[i]);
> 
>       /*
>        * Acl update can result in inode attribute update.
> @@ -4700,12 +4617,12 @@ static int __nfs4_proc_set_acl(struct inode *inode, 
> const void *buf, size_t bufl
>       return ret;
> }
> 
> -static int nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t 
> buflen)
> +static int nfs4_proc_set_acl(struct inode *inode, struct richacl *acl)
> {
>       struct nfs4_exception exception = { };
>       int err;
>       do {
> -             err = __nfs4_proc_set_acl(inode, buf, buflen);
> +             err = __nfs4_proc_set_acl(inode, acl);
>               trace_nfs4_set_acl(inode, err);
>               err = nfs4_handle_exception(NFS_SERVER(inode), err,
>                               &exception);
> @@ -6102,38 +6019,69 @@ nfs4_release_lockowner(struct nfs_server *server, 
> struct nfs4_lock_state *lsp)
>       rpc_call_async(server->client, &msg, 0, &nfs4_release_lockowner_ops, 
> data);
> }
> 
> -#define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
> -
> -static int nfs4_xattr_set_nfs4_acl(struct dentry *dentry, const char *key,
> -                                const void *buf, size_t buflen,
> -                                int flags, int type)
> +static int nfs4_xattr_set_richacl(struct dentry *dentry, const char *key,
> +                               const void *buf, size_t buflen,
> +                               int flags, int handler_flags)
> {
> +     struct richacl *acl;
> +     int error;
> +
>       if (strcmp(key, "") != 0)
>               return -EINVAL;
> 
> -     return nfs4_proc_set_acl(dentry->d_inode, buf, buflen);
> +     if (buf) {
> +             acl = richacl_from_xattr(&init_user_ns, buf, buflen);
> +             if (IS_ERR(acl))
> +                     return PTR_ERR(acl);
> +             error = richacl_apply_masks(&acl);

Hi Andreas,

First, let me say thanks for all the work! We (Primary Data) have been using
samba with the vfs_richacl module reexporting an nfsv4.2 mount and things are
working pretty well. You can count on us for testing, bug fixing and code 
review.

Now for my question: It looks like this call to richacl_apply_masks in the 
client
xattr_set path exists so that the knfsd permission check algorithm works 
correctly.
This makes some pretty big assumptions about the server’s implementation.
There are other servers out there besides knfsd!

I think this will have to be fixed before this patch can be accepted. I’m 
willing to
help, but I’m wondering where this should be fixed:

Do we call richacl_apply_masks on the server before setting the xattr so the
normalized acl is saved, or should we save the ACL as-is and call
richacl_apply_masks before it’s used?

Thanks,

-dros

> +     } else {
> +             /*
> +              * "Remove the acl"; only permissions granted by the mode
> +              * remain.  We are using the cached mode here which could be
> +              * outdated; should we do a GETATTR first to narrow down the
> +              * race window?
> +              */
> +             acl = richacl_from_mode_unmasked(dentry->d_inode->i_mode);
> +             error = 0;
> +     }
> +
> +     if (!error)
> +             error = nfs4_proc_set_acl(dentry->d_inode, acl);
> +     richacl_put(acl);
> +     return error;
> }
> 
> -static int nfs4_xattr_get_nfs4_acl(struct dentry *dentry, const char *key,
> -                                void *buf, size_t buflen, int type)
> +static int nfs4_xattr_get_richacl(struct dentry *dentry, const char *key,
> +                               void *buf, size_t buflen, int handler_flags)
> {
> +     struct richacl *acl;
> +     int error;
> +
>       if (strcmp(key, "") != 0)
>               return -EINVAL;
> 
> -     return nfs4_proc_get_acl(dentry->d_inode, buf, buflen);
> +     acl = nfs4_proc_get_acl(dentry->d_inode);
> +     if (IS_ERR(acl))
> +             return PTR_ERR(acl);
> +     if (acl == NULL)
> +             return -ENODATA;
> +     error = richacl_to_xattr(&init_user_ns, acl, buf, buflen);
> +     richacl_put(acl);
> +     return error;
> }
> 
> -static size_t nfs4_xattr_list_nfs4_acl(struct dentry *dentry, char *list,
> -                                    size_t list_len, const char *name,
> -                                    size_t name_len, int type)
> +static size_t nfs4_xattr_list_richacl(struct dentry *dentry, char *list,
> +                                   size_t list_len, const char *name,
> +                                   size_t name_len, int handler_flags)
> {
> -     size_t len = sizeof(XATTR_NAME_NFSV4_ACL);
> +     struct nfs_server *server = NFS_SERVER(dentry->d_inode);
> +     size_t len = sizeof(XATTR_NAME_RICHACL);
> 
> -     if (!nfs4_server_supports_acls(NFS_SERVER(dentry->d_inode)))
> +     if (!(server->caps & (NFS_CAP_ALLOW_ACLS | NFS_CAP_DENY_ACLS)))
>               return 0;
> 
>       if (list && len <= list_len)
> -             memcpy(list, XATTR_NAME_NFSV4_ACL, len);
> +             memcpy(list, XATTR_NAME_RICHACL, len);
>       return len;
> }
> 
> @@ -8656,15 +8604,15 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
>       .clone_server   = nfs_clone_server,
> };
> 
> -static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
> -     .prefix = XATTR_NAME_NFSV4_ACL,
> -     .list   = nfs4_xattr_list_nfs4_acl,
> -     .get    = nfs4_xattr_get_nfs4_acl,
> -     .set    = nfs4_xattr_set_nfs4_acl,
> +static const struct xattr_handler nfs4_xattr_richacl_handler = {
> +     .prefix = XATTR_NAME_RICHACL,
> +     .list   = nfs4_xattr_list_richacl,
> +     .get    = nfs4_xattr_get_richacl,
> +     .set    = nfs4_xattr_set_richacl,
> };
> 
> const struct xattr_handler *nfs4_xattr_handlers[] = {
> -     &nfs4_xattr_nfs4_acl_handler,
> +     &nfs4_xattr_richacl_handler,
> #ifdef CONFIG_NFS_V4_SECURITY_LABEL
>       &nfs4_xattr_nfs4_label_handler,
> #endif
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index 4372fc4..8ccc2a0 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -53,6 +53,9 @@
> #include <linux/nfs4.h>
> #include <linux/nfs_fs.h>
> #include <linux/nfs_idmap.h>
> +#include <linux/richacl.h>
> +#include <linux/richacl_xattr.h>  /* for RICHACL_XATTR_MAX_COUNT */
> +#include <linux/nfs4acl.h>
> 
> #include "nfs4_fs.h"
> #include "internal.h"
> @@ -1632,19 +1635,131 @@ encode_restorefh(struct xdr_stream *xdr, struct 
> compound_hdr *hdr)
>       encode_op_hdr(xdr, OP_RESTOREFH, decode_restorefh_maxsz, hdr);
> }
> 
> -static void
> -encode_setacl(struct xdr_stream *xdr, struct nfs_setaclargs *arg, struct 
> compound_hdr *hdr)
> +static int
> +nfs4_encode_user(struct xdr_stream *xdr, const struct nfs_server *server, 
> kuid_t uid)
> +{
> +     char name[IDMAP_NAMESZ];
> +     int len;
> +     __be32 *p;
> +
> +     len = nfs_map_uid_to_name(server, uid, name, IDMAP_NAMESZ);
> +     if (len < 0) {
> +             dprintk("nfs: couldn't resolve uid %d to string\n",
> +                             from_kuid(&init_user_ns, uid));
> +             return -ENOENT;
> +     }
> +     p = xdr_reserve_space(xdr, 4 + len);
> +     if (!p)
> +             return -EIO;
> +     p = xdr_encode_opaque(p, name, len);
> +     return 0;
> +}
> +
> +static int
> +nfs4_encode_group(struct xdr_stream *xdr, const struct nfs_server *server, 
> kgid_t gid)
> +{
> +     char name[IDMAP_NAMESZ];
> +     int len;
> +     __be32 *p;
> +
> +     len = nfs_map_gid_to_group(server, gid, name, IDMAP_NAMESZ);
> +     if (len < 0) {
> +             dprintk("nfs: couldn't resolve gid %d to string\n",
> +                             from_kgid(&init_user_ns, gid));
> +             return -ENOENT;
> +     }
> +     p = xdr_reserve_space(xdr, 4 + len);
> +     if (!p)
> +             return -EIO;
> +     p = xdr_encode_opaque(p, name, len);
> +     return 0;
> +}
> +
> +static int
> +nfs4_encode_ace_who(struct xdr_stream *xdr, const struct nfs_server *server,
> +                 struct richace *ace)
> {
>       __be32 *p;
> 
> +     if (ace->e_flags & RICHACE_SPECIAL_WHO) {
> +             unsigned int special_id = ace->e_id.special;
> +             const char *who;
> +             unsigned int len;
> +
> +             if (!nfs4acl_special_id_to_who(special_id, &who, &len)) {
> +                     WARN_ON_ONCE(1);
> +                     return -EIO;
> +             }
> +             p = xdr_reserve_space(xdr, 4 + len);
> +             if (!p)
> +                     return -EIO;
> +             p = xdr_encode_opaque(p, who, len);
> +             return 0;
> +     }
> +     if (ace->e_flags & RICHACE_IDENTIFIER_GROUP)
> +             return nfs4_encode_group(xdr, server, ace->e_id.gid);
> +     else
> +             return nfs4_encode_user(xdr, server, ace->e_id.uid);
> +}
> +
> +static int
> +encode_setacl(struct xdr_stream *xdr, struct nfs_setaclargs *arg, struct 
> compound_hdr *hdr)
> +{
> +     int attrlen_offset;
> +     __be32 attrlen, *p;
> +     struct richace *ace;
> +
>       encode_op_hdr(xdr, OP_SETATTR, decode_setacl_maxsz, hdr);
>       encode_nfs4_stateid(xdr, &zero_stateid);
> +
> +     /* Encode attribute bitmap. */
>       p = reserve_space(xdr, 2*4);
>       *p++ = cpu_to_be32(1);
>       *p = cpu_to_be32(FATTR4_WORD0_ACL);
> -     p = reserve_space(xdr, 4);
> -     *p = cpu_to_be32(arg->acl_len);
> -     xdr_write_pages(xdr, arg->acl_pages, 0, arg->acl_len);
> +
> +     attrlen_offset = xdr->buf->len;
> +     p = xdr_reserve_space(xdr, 4);
> +     if (!p)
> +             goto fail;
> +     p++;  /* to be backfilled later */
> +
> +     p = xdr_reserve_space(xdr, 4);
> +     if (!p)
> +             goto fail;
> +     if (arg->acl == NULL) {
> +             *p++ = cpu_to_be32(0);
> +             return 0;
> +     }
> +     *p++ = cpu_to_be32(arg->acl->a_count);
> +
> +     /* Add space for the acl entries. */
> +     xdr_inline_pages(xdr->buf, xdr->buf->len, arg->acl_pages, 0, 
> arg->acl_len);
> +
> +     if (arg->acl->a_flags)
> +             return -EINVAL;
> +
> +     richacl_for_each_entry(ace, arg->acl) {
> +             if (ace->e_flags & RICHACE_INHERITED_ACE)
> +                     return -EINVAL;
> +             if (ace->e_mask & ~NFS4_ACE_MASK_ALL)
> +                     return -EINVAL;
> +
> +             p = xdr_reserve_space(xdr, 4*3);
> +             if (!p)
> +                     goto fail;
> +             *p++ = cpu_to_be32(ace->e_type);
> +             *p++ = cpu_to_be32(ace->e_flags & ~RICHACE_SPECIAL_WHO);
> +             *p++ = cpu_to_be32(ace->e_mask & NFS4_ACE_MASK_ALL);
> +             if (nfs4_encode_ace_who(xdr, arg->server, ace) != 0)
> +                     goto fail;
> +     }
> +
> +     attrlen = htonl(xdr->buf->len - attrlen_offset - 4);
> +     write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4);
> +     return 0;
> +
> +fail:
> +     return -ENOMEM;
> }
> 
> static void
> @@ -2514,7 +2629,7 @@ static int nfs4_xdr_enc_getacl(struct rpc_rqst *req, 
> struct xdr_stream *xdr,
>       encode_sequence(xdr, &args->seq_args, &hdr);
>       encode_putfh(xdr, args->fh, &hdr);
>       replen = hdr.replen + op_decode_hdr_maxsz + 1;
> -     encode_getattr_two(xdr, FATTR4_WORD0_ACL, 0, &hdr);
> +     encode_getattr_two(xdr, FATTR4_WORD0_ACL, FATTR4_WORD1_MODE, &hdr);
> 
>       xdr_inline_pages(&req->rq_rcv_buf, replen << 2,
>               args->acl_pages, 0, args->acl_len);
> @@ -5236,27 +5351,64 @@ decode_restorefh(struct xdr_stream *xdr)
>       return decode_op_hdr(xdr, OP_RESTOREFH);
> }
> 
> +static int
> +nfs4_decode_ace_who(struct richace *ace, const struct nfs_server *server,
> +                 struct xdr_stream *xdr)
> +{
> +     char *who;
> +     u32 len;
> +     int special_id;
> +     __be32 *p;
> +     int error;
> +
> +     p = xdr_inline_decode(xdr, 4);
> +     if (!p)
> +             return -ENOMEM;  /* acl truncated */
> +     len = be32_to_cpup(p++);
> +     if (len >= XDR_MAX_NETOBJ) {
> +             dprintk("%s: name too long (%u)!\n",
> +                     __func__, len);
> +             return -EIO;
> +     }
> +     who = (char *)xdr_inline_decode(xdr, len);
> +     if (!who)
> +             return -ENOMEM;  /* acl truncated */
> +
> +     special_id = nfs4acl_who_to_special_id(who, len);
> +     if (special_id >= 0) {
> +             ace->e_flags |= RICHACE_SPECIAL_WHO;
> +             ace->e_flags &= ~RICHACE_IDENTIFIER_GROUP;
> +             ace->e_id.special = special_id;
> +             return 0;
> +     }
> +     if (ace->e_flags & RICHACE_IDENTIFIER_GROUP) {
> +             error = nfs_map_group_to_gid(server, who, len, &ace->e_id.gid);
> +             if (error)
> +                     dprintk("%s: nfs_map_group_to_gid failed!\n",
> +                                     __func__);
> +     } else {
> +             error = nfs_map_name_to_uid(server, who, len, &ace->e_id.uid);
> +             if (error)
> +                     dprintk("%s: nfs_map_name_to_uid failed!\n",
> +                                     __func__);
> +     }
> +     return error;
> +}
> +
> static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
>                        struct nfs_getaclres *res)
> {
>       static const uint32_t attrs_allowed[3] = {
>               [0] = FATTR4_WORD0_ACL,
> +             [1] = FATTR4_WORD1_MODE,
>       };
>       unsigned int savep;
>       uint32_t attrlen,
>                bitmap[3] = {0};
>       int status;
> -     unsigned int pg_offset;
> 
> -     res->acl_len = 0;
>       if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
>               goto out;
> -
> -     xdr_enter_page(xdr, xdr->buf->page_len);
> -
> -     /* Calculate the offset of the page data */
> -     pg_offset = xdr->buf->head[0].iov_len;
> -
>       if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
>               goto out;
>       if ((status = verify_attrs_allowed(bitmap, attrs_allowed)) != 0)
> @@ -5265,22 +5417,37 @@ static int decode_getacl(struct xdr_stream *xdr, 
> struct rpc_rqst *req,
>               goto out;
> 
>       if (likely(bitmap[0] & FATTR4_WORD0_ACL)) {
> +             struct richace *ace;
> +             uint32_t count;
> +             __be32 *p;
> 
> -             /* The bitmap (xdr len + bitmaps) and the attr xdr len words
> -              * are stored with the acl data to handle the problem of
> -              * variable length bitmaps.*/
> -             res->acl_data_offset = xdr_stream_pos(xdr) - pg_offset;
> -             res->acl_len = attrlen;
> -
> -             /* Check for receive buffer overflow */
> -             if (res->acl_len > (xdr->nwords << 2) ||
> -                 res->acl_len + res->acl_data_offset > xdr->buf->page_len) {
> -                     res->acl_flags |= NFS4_ACL_TRUNC;
> -                     dprintk("NFS: acl reply: attrlen %u > page_len %u\n",
> -                                     attrlen, xdr->nwords << 2);
> +             p = xdr_inline_decode(xdr, 4);
> +             if (unlikely(!p))
> +                     return -ENOMEM;  /* acl truncated */
> +             count = be32_to_cpup(p);
> +             if (count > RICHACL_XATTR_MAX_COUNT)
> +                     return -EIO;
> +             res->acl = richacl_alloc(count, GFP_KERNEL);
> +             if (!res->acl)
> +                     return -ENOMEM;
> +             richacl_for_each_entry(ace, res->acl) {
> +                     p = xdr_inline_decode(xdr, 4*3);
> +                     if (unlikely(!p))
> +                             return -ENOMEM;  /* acl truncated */
> +                     ace->e_type = be32_to_cpup(p++);
> +                     ace->e_flags = be32_to_cpup(p++);
> +                     if (ace->e_flags & RICHACE_SPECIAL_WHO)
> +                             return -EIO;
> +                     ace->e_mask = be32_to_cpup(p++);
> +                     status = nfs4_decode_ace_who(ace, res->server, xdr);
> +                     if (status)
> +                             goto out;
>               }
>       } else
>               status = -EOPNOTSUPP;
> +     if ((status = decode_attr_mode(xdr, bitmap, &res->mode)) < 0)
> +             goto out;
> +     status = 0;
> 
> out:
>       return status;
> @@ -6298,6 +6465,7 @@ out:
> static int nfs4_xdr_enc_setacl(struct rpc_rqst *req, struct xdr_stream *xdr,
>                              void *obj)
> {
> +     int error;
>       struct nfs_setaclargs *args = obj;
>       struct compound_hdr hdr = {
>               .minorversion = nfs4_xdr_minorversion(&args->seq_args),
> @@ -6306,7 +6474,9 @@ static int nfs4_xdr_enc_setacl(struct rpc_rqst *req, 
> struct xdr_stream *xdr,
>       encode_compound_hdr(xdr, req, &hdr);
>       encode_sequence(xdr, &args->seq_args, &hdr);
>       encode_putfh(xdr, args->fh, &hdr);
> -     encode_setacl(xdr, args, &hdr);
> +     error = encode_setacl(xdr, args, &hdr);
> +     if (error)
> +             return error;
>       encode_nops(&hdr);
>       return 0;
> }
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 322b2de02..fb904ec 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -2318,7 +2318,7 @@ void nfs_fill_super(struct super_block *sb, struct 
> nfs_mount_info *mount_info)
>               /* The VFS shouldn't apply the umask to mode bits. We will do
>                * so ourselves when necessary.
>                */
> -             sb->s_flags |= MS_POSIXACL;
> +             sb->s_flags |= MS_RICHACL;
>               sb->s_time_gran = 1;
>       }
> 
> @@ -2345,7 +2345,7 @@ void nfs_clone_super(struct super_block *sb, struct 
> nfs_mount_info *mount_info)
>               /* The VFS shouldn't apply the umask to mode bits. We will do
>                * so ourselves when necessary.
>                */
> -             sb->s_flags |= MS_POSIXACL;
> +             sb->s_flags |= MS_RICHACL;
>       }
> 
>       nfs_initialise_sb(sb);
> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> index b01ccf3..4eac89d7 100644
> --- a/include/linux/nfs_fs.h
> +++ b/include/linux/nfs_fs.h
> @@ -176,7 +176,6 @@ struct nfs_inode {
>       wait_queue_head_t       waitqueue;
> 
> #if IS_ENABLED(CONFIG_NFS_V4)
> -     struct nfs4_cached_acl  *nfs4_acl;
>         /* NFSv4 state */
>       struct list_head        open_states;
>       struct nfs_delegation __rcu *delegation;
> diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
> index 5e1273d..df994aa 100644
> --- a/include/linux/nfs_fs_sb.h
> +++ b/include/linux/nfs_fs_sb.h
> @@ -237,5 +237,7 @@ struct nfs_server {
> #define NFS_CAP_SEEK          (1U << 19)
> #define NFS_CAP_ALLOCATE      (1U << 20)
> #define NFS_CAP_DEALLOCATE    (1U << 21)
> +#define NFS_CAP_ALLOW_ACLS   (1U << 22)
> +#define NFS_CAP_DENY_ACLS    (1U << 23)
> 
> #endif
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index 92134cf..77097ec 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -638,7 +638,9 @@ struct nfs_setattrargs {
> 
> struct nfs_setaclargs {
>       struct nfs4_sequence_args       seq_args;
> +     const struct nfs_server *       server;
>       struct nfs_fh *                 fh;
> +     struct richacl *                acl;
>       size_t                          acl_len;
>       struct page **                  acl_pages;
> };
> @@ -658,9 +660,9 @@ struct nfs_getaclargs {
> #define NFS4_ACL_TRUNC                0x0001  /* ACL was truncated */
> struct nfs_getaclres {
>       struct nfs4_sequence_res        seq_res;
> -     size_t                          acl_len;
> -     size_t                          acl_data_offset;
> -     int                             acl_flags;
> +     const struct nfs_server *       server;
> +     struct richacl *                acl;
> +     umode_t                         mode;
>       struct page *                   acl_scratch;
> };
> 
> -- 
> 2.1.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to [email protected]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to