* [PATCH v2 01/11] xattr: break delegations in {set,remove}xattr and add _locked versions
[not found] <20200327232717.15331-1-fllinden@amazon.com>
@ 2020-03-27 23:27 ` Frank van der Linden
2020-03-31 13:11 ` Sasha Levin
2020-03-27 23:27 ` [PATCH v2 02/11] xattr: add a function to check if a namespace is supported Frank van der Linden
2020-03-27 23:27 ` [PATCH v2 10/11] nfsd: implement the xattr functions and en/decode logic Frank van der Linden
2 siblings, 1 reply; 7+ messages in thread
From: Frank van der Linden @ 2020-03-27 23:27 UTC (permalink / raw)
To: bfields, chuck.lever, linux-nfs
Cc: Frank van der Linden, linux-fsdevel, Al Viro
set/removexattr on an exported filesystem should break NFS delegations.
This is true in general, but also for the upcoming support for
RFC 8726 (NFSv4 extended attribute support). Make sure that they do.
Additonally, they need to grow a _locked variant, since the NFS server code
will call this with i_rwsem held. It needs to do that in fh_lock to be
able to atomically provide the before and after change attributes.
Cc: stable@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
---
fs/xattr.c | 84 +++++++++++++++++++++++++++++++++++++++----
include/linux/xattr.h | 2 ++
2 files changed, 79 insertions(+), 7 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 90dd78f0eb27..f2854570d411 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -204,10 +204,22 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name,
return error;
}
-
+/**
+ * __vfs_setxattr_locked: set an extended attribute while holding the inode
+ * lock
+ *
+ * @dentry - object to perform setxattr on
+ * @name - xattr name to set
+ * @value - value to set @name to
+ * @size - size of @value
+ * @flags - flags to pass into filesystem operations
+ * @delegated_inode - on return, will contain an inode pointer that
+ * a delegation was broken on, NULL if none.
+ */
int
-vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
- size_t size, int flags)
+__vfs_setxattr_locked(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags,
+ struct inode **delegated_inode)
{
struct inode *inode = dentry->d_inode;
int error;
@@ -216,15 +228,40 @@ vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
if (error)
return error;
- inode_lock(inode);
error = security_inode_setxattr(dentry, name, value, size, flags);
if (error)
goto out;
+ error = try_break_deleg(inode, delegated_inode);
+ if (error)
+ goto out;
+
error = __vfs_setxattr_noperm(dentry, name, value, size, flags);
out:
+ return error;
+}
+EXPORT_SYMBOL_GPL(__vfs_setxattr_locked);
+
+int
+vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
+{
+ struct inode *inode = dentry->d_inode;
+ struct inode *delegated_inode = NULL;
+ int error;
+
+retry_deleg:
+ inode_lock(inode);
+ error = __vfs_setxattr_locked(dentry, name, value, size, flags,
+ &delegated_inode);
inode_unlock(inode);
+
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
return error;
}
EXPORT_SYMBOL_GPL(vfs_setxattr);
@@ -378,8 +415,18 @@ __vfs_removexattr(struct dentry *dentry, const char *name)
}
EXPORT_SYMBOL(__vfs_removexattr);
+/**
+ * __vfs_removexattr_locked: set an extended attribute while holding the inode
+ * lock
+ *
+ * @dentry - object to perform setxattr on
+ * @name - name of xattr to remove
+ * @delegated_inode - on return, will contain an inode pointer that
+ * a delegation was broken on, NULL if none.
+ */
int
-vfs_removexattr(struct dentry *dentry, const char *name)
+__vfs_removexattr_locked(struct dentry *dentry, const char *name,
+ struct inode **delegated_inode)
{
struct inode *inode = dentry->d_inode;
int error;
@@ -388,11 +435,14 @@ vfs_removexattr(struct dentry *dentry, const char *name)
if (error)
return error;
- inode_lock(inode);
error = security_inode_removexattr(dentry, name);
if (error)
goto out;
+ error = try_break_deleg(inode, delegated_inode);
+ if (error)
+ goto out;
+
error = __vfs_removexattr(dentry, name);
if (!error) {
@@ -401,12 +451,32 @@ vfs_removexattr(struct dentry *dentry, const char *name)
}
out:
+ return error;
+}
+EXPORT_SYMBOL_GPL(__vfs_removexattr_locked);
+
+int
+vfs_removexattr(struct dentry *dentry, const char *name)
+{
+ struct inode *inode = dentry->d_inode;
+ struct inode *delegated_inode = NULL;
+ int error;
+
+retry_deleg:
+ inode_lock(inode);
+ error = __vfs_removexattr_locked(dentry, name, &delegated_inode);
inode_unlock(inode);
+
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
+
return error;
}
EXPORT_SYMBOL_GPL(vfs_removexattr);
-
/*
* Extended attribute SET operations
*/
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 6dad031be3c2..3a71ad716da5 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -51,8 +51,10 @@ ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int);
int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
+int __vfs_setxattr_locked(struct dentry *, const char *, const void *, size_t, int, struct inode **);
int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
int __vfs_removexattr(struct dentry *, const char *);
+int __vfs_removexattr_locked(struct dentry *, const char *, struct inode **);
int vfs_removexattr(struct dentry *, const char *);
ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
--
2.17.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 10/11] nfsd: implement the xattr functions and en/decode logic
[not found] <20200327232717.15331-1-fllinden@amazon.com>
2020-03-27 23:27 ` [PATCH v2 01/11] xattr: break delegations in {set,remove}xattr and add _locked versions Frank van der Linden
2020-03-27 23:27 ` [PATCH v2 02/11] xattr: add a function to check if a namespace is supported Frank van der Linden
@ 2020-03-27 23:27 ` Frank van der Linden
2020-03-29 20:25 ` vfs_listxattr and the NFS server: namespaces Frank van der Linden
2 siblings, 1 reply; 7+ messages in thread
From: Frank van der Linden @ 2020-03-27 23:27 UTC (permalink / raw)
To: bfields, chuck.lever, linux-nfs; +Cc: Frank van der Linden, linux-fsdevel
Implement the main entry points for the *XATTR operations.
Add functions to calculate the reply size for the user extended attribute
operations, and implement the XDR encode / decode logic for these
operations.
Add the user extended attributes operations to nfsd4_ops.
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
---
fs/nfsd/nfs4proc.c | 132 +++++++++++++
fs/nfsd/nfs4xdr.c | 450 +++++++++++++++++++++++++++++++++++++++++++
include/linux/nfs4.h | 2 +-
3 files changed, 583 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index ee317ae0b609..bb00982f5c6a 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -2098,6 +2098,80 @@ nfsd4_layoutreturn(struct svc_rqst *rqstp,
}
#endif /* CONFIG_NFSD_PNFS */
+static __be32
+nfsd4_getxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+ union nfsd4_op_u *u)
+{
+ struct nfsd4_getxattr *getxattr = &u->getxattr;
+
+ return nfsd_getxattr(rqstp, &cstate->current_fh,
+ getxattr->getxa_name, getxattr->getxa_buf,
+ &getxattr->getxa_len);
+}
+
+static __be32
+nfsd4_setxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+ union nfsd4_op_u *u)
+{
+ struct nfsd4_setxattr *setxattr = &u->setxattr;
+ __be32 ret;
+
+ if (opens_in_grace(SVC_NET(rqstp)))
+ return nfserr_grace;
+
+ ret = nfsd_setxattr(rqstp, &cstate->current_fh, setxattr->setxa_name,
+ setxattr->setxa_buf, setxattr->setxa_len,
+ setxattr->setxa_flags);
+
+ if (!ret)
+ set_change_info(&setxattr->setxa_cinfo, &cstate->current_fh);
+
+ return ret;
+}
+
+static __be32
+nfsd4_listxattrs(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+ union nfsd4_op_u *u)
+{
+ int len;
+ __be32 ret;
+
+ /*
+ * Get the entire list, then copy out only the user attributes
+ * in the encode function. lsxa_buf was previously allocated as
+ * tmp svc space, and will be automatically freed later.
+ */
+ len = XATTR_LIST_MAX;
+
+ ret = nfsd_listxattr(rqstp, &cstate->current_fh, u->listxattrs.lsxa_buf,
+ &len);
+ if (ret)
+ return ret;
+
+ u->listxattrs.lsxa_len = len;
+
+ return nfs_ok;
+}
+
+static __be32
+nfsd4_removexattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+ union nfsd4_op_u *u)
+{
+ struct nfsd4_removexattr *removexattr = &u->removexattr;
+ __be32 ret;
+
+ if (opens_in_grace(SVC_NET(rqstp)))
+ return nfserr_grace;
+
+ ret = nfsd_removexattr(rqstp, &cstate->current_fh,
+ removexattr->rmxa_name);
+
+ if (!ret)
+ set_change_info(&removexattr->rmxa_cinfo, &cstate->current_fh);
+
+ return ret;
+}
+
/*
* NULL call.
*/
@@ -2705,6 +2779,42 @@ static inline u32 nfsd4_seek_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
return (op_encode_hdr_size + 3) * sizeof(__be32);
}
+static inline u32 nfsd4_getxattr_rsize(struct svc_rqst *rqstp,
+ struct nfsd4_op *op)
+{
+ u32 maxcount, rlen;
+
+ maxcount = svc_max_payload(rqstp);
+ rlen = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+ return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_setxattr_rsize(struct svc_rqst *rqstp,
+ struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_change_info_maxsz)
+ * sizeof(__be32);
+}
+static inline u32 nfsd4_listxattrs_rsize(struct svc_rqst *rqstp,
+ struct nfsd4_op *op)
+{
+ u32 maxcount, rlen;
+
+ maxcount = svc_max_payload(rqstp);
+ rlen = min(op->u.listxattrs.lsxa_maxcount, maxcount);
+
+ return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_removexattr_rsize(struct svc_rqst *rqstp,
+ struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_change_info_maxsz)
+ * sizeof(__be32);
+}
+
+
static const struct nfsd4_operation nfsd4_ops[] = {
[OP_ACCESS] = {
.op_func = nfsd4_access,
@@ -3086,6 +3196,28 @@ static const struct nfsd4_operation nfsd4_ops[] = {
.op_name = "OP_COPY_NOTIFY",
.op_rsize_bop = nfsd4_copy_notify_rsize,
},
+ [OP_GETXATTR] = {
+ .op_func = nfsd4_getxattr,
+ .op_name = "OP_GETXATTR",
+ .op_rsize_bop = nfsd4_getxattr_rsize,
+ },
+ [OP_SETXATTR] = {
+ .op_func = nfsd4_setxattr,
+ .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+ .op_name = "OP_SETXATTR",
+ .op_rsize_bop = nfsd4_setxattr_rsize,
+ },
+ [OP_LISTXATTRS] = {
+ .op_func = nfsd4_listxattrs,
+ .op_name = "OP_LISTXATTRS",
+ .op_rsize_bop = nfsd4_listxattrs_rsize,
+ },
+ [OP_REMOVEXATTR] = {
+ .op_func = nfsd4_removexattr,
+ .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+ .op_name = "OP_REMOVEXATTR",
+ .op_rsize_bop = nfsd4_removexattr_rsize,
+ },
};
/**
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index f6322add2992..4c4508f1bb8e 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -41,6 +41,8 @@
#include <linux/pagemap.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/addr.h>
+#include <linux/xattr.h>
+#include <uapi/linux/xattr.h>
#include "idmap.h"
#include "acl.h"
@@ -1877,6 +1879,224 @@ nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
DECODE_TAIL;
}
+/*
+ * XDR data that is more than PAGE_SIZE in size is normally part of a
+ * read or write. However, the size of extended attributes is limited
+ * by the maximum request size, and then further limited by the underlying
+ * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
+ * is 64k). Since there is no kvec- or page-based interface to xattrs,
+ * and we're not dealing with contiguous pages, we need to do some copying.
+ */
+
+/*
+ * Decode data into buffer. Uses head and pages constructed by
+ * svcxdr_construct_vector.
+ */
+static __be32
+nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct kvec *head,
+ struct page **pages, char **bufp, u32 buflen)
+{
+ char *tmp, *dp;
+ u32 len;
+
+ if (buflen <= head->iov_len) {
+ /*
+ * We're in luck, the head has enough space. Just return
+ * the head, no need for copying.
+ */
+ *bufp = head->iov_base;
+ return 0;
+ }
+
+ tmp = svcxdr_tmpalloc(argp, buflen);
+ if (tmp == NULL)
+ return nfserr_jukebox;
+
+ dp = tmp;
+ memcpy(dp, head->iov_base, head->iov_len);
+ buflen -= head->iov_len;
+ dp += head->iov_len;
+
+ while (buflen > 0) {
+ len = min_t(u32, buflen, PAGE_SIZE);
+ memcpy(dp, page_address(*pages), len);
+
+ buflen -= len;
+ dp += len;
+ pages++;
+ }
+
+ *bufp = tmp;
+ return 0;
+}
+
+/*
+ * Get a user extended attribute name from the XDR buffer.
+ * It will not have the "user." prefix, so prepend it.
+ * Lastly, check for nul characters in the name.
+ */
+static __be32
+nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
+{
+ DECODE_HEAD;
+ char *name, *sp, *dp;
+ u32 namelen, cnt;
+
+ READ_BUF(4);
+ namelen = be32_to_cpup(p++);
+
+ if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
+ return nfserr_nametoolong;
+
+ if (namelen == 0)
+ goto xdr_error;
+
+ READ_BUF(namelen);
+
+ name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
+ if (!name)
+ return nfserr_jukebox;
+
+ memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+
+ /*
+ * Copy the extended attribute name over while checking for 0
+ * characters.
+ */
+ sp = (char *)p;
+ dp = name + XATTR_USER_PREFIX_LEN;
+ cnt = namelen;
+
+ while (cnt-- > 0) {
+ if (*sp == '\0')
+ goto xdr_error;
+ *dp++ = *sp++;
+ }
+ *dp = '\0';
+
+ *namep = name;
+
+ DECODE_TAIL;
+}
+
+/*
+ * A GETXATTR op request comes without a length specifier. We just set the
+ * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
+ * channel reply size, allocate a buffer of that length and pass it to
+ * vfs_getxattr.
+ */
+static __be32
+nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
+ struct nfsd4_getxattr *getxattr)
+{
+ __be32 status;
+ u32 maxcount;
+
+ status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
+ if (status)
+ return status;
+
+ maxcount = svc_max_payload(argp->rqstp);
+ maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+ getxattr->getxa_buf = svcxdr_tmpalloc(argp, maxcount);
+ if (!getxattr->getxa_buf)
+ status = nfserr_jukebox;
+ getxattr->getxa_len = maxcount;
+
+ return status;
+}
+
+static __be32
+nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
+ struct nfsd4_setxattr *setxattr)
+{
+ DECODE_HEAD;
+ u32 flags, maxcount, size;
+ struct kvec head;
+ struct page **pagelist;
+
+ READ_BUF(4);
+ flags = be32_to_cpup(p++);
+
+ if (flags > SETXATTR4_REPLACE)
+ return nfserr_inval;
+ setxattr->setxa_flags = flags;
+
+ status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
+ if (status)
+ return status;
+
+ maxcount = svc_max_payload(argp->rqstp);
+ maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+ READ_BUF(4);
+ size = be32_to_cpup(p++);
+ if (size > maxcount)
+ return nfserr_xattr2big;
+
+ setxattr->setxa_len = size;
+ if (size > 0) {
+ status = svcxdr_construct_vector(argp, &head, &pagelist, size);
+ if (status)
+ return status;
+
+ status = nfsd4_vbuf_from_vector(argp, &head, pagelist,
+ &setxattr->setxa_buf, size);
+ }
+
+ DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
+ struct nfsd4_listxattrs *listxattrs)
+{
+ DECODE_HEAD;
+ u32 maxcount;
+
+ READ_BUF(12);
+ p = xdr_decode_hyper(p, &listxattrs->lsxa_cookie);
+
+ /*
+ * If the cookie is too large to have even one user.x attribute
+ * plus trailing '\0' left in a maximum size buffer, it's invalid.
+ */
+ if (listxattrs->lsxa_cookie >=
+ (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
+ return nfserr_badcookie;
+
+ maxcount = be32_to_cpup(p++);
+ if (maxcount < 8)
+ /* Always need at least 2 words (length and one character) */
+ return nfserr_inval;
+
+ maxcount = min(maxcount, svc_max_payload(argp->rqstp));
+ listxattrs->lsxa_maxcount = maxcount;
+
+ /*
+ * Unfortunately, there is no interface to only list xattrs for
+ * one prefix. So there is no good way to convert maxcount to
+ * a maximum value to pass to vfs_listxattr, as we don't know
+ * how many of the returned attributes will be user attributes.
+ *
+ * So, always ask vfs_listxattr for the maximum size, and encode
+ * as many as possible.
+ */
+ listxattrs->lsxa_buf = svcxdr_tmpalloc(argp, XATTR_LIST_MAX);
+ if (!listxattrs->lsxa_buf)
+ status = nfserr_jukebox;
+
+ DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
+ struct nfsd4_removexattr *removexattr)
+{
+ return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
+}
+
static __be32
nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
{
@@ -1973,6 +2193,11 @@ static const nfsd4_dec nfsd4_dec_ops[] = {
[OP_SEEK] = (nfsd4_dec)nfsd4_decode_seek,
[OP_WRITE_SAME] = (nfsd4_dec)nfsd4_decode_notsupp,
[OP_CLONE] = (nfsd4_dec)nfsd4_decode_clone,
+ /* RFC 8276 extended atributes operations */
+ [OP_GETXATTR] = (nfsd4_dec)nfsd4_decode_getxattr,
+ [OP_SETXATTR] = (nfsd4_dec)nfsd4_decode_setxattr,
+ [OP_LISTXATTRS] = (nfsd4_dec)nfsd4_decode_listxattrs,
+ [OP_REMOVEXATTR] = (nfsd4_dec)nfsd4_decode_removexattr,
};
static inline bool
@@ -4456,6 +4681,225 @@ nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
return nfserr;
}
+/*
+ * Encode kmalloc-ed buffer in to XDR stream.
+ */
+static int
+nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
+{
+ u32 cplen;
+ __be32 *p;
+
+ cplen = min_t(unsigned long, buflen,
+ ((void *)xdr->end - (void *)xdr->p));
+ p = xdr_reserve_space(xdr, cplen);
+ if (!p)
+ return nfserr_resource;
+
+ memcpy(p, buf, cplen);
+ buf += cplen;
+ buflen -= cplen;
+
+ while (buflen) {
+ cplen = min_t(u32, buflen, PAGE_SIZE);
+ p = xdr_reserve_space(xdr, cplen);
+ if (!p)
+ return nfserr_resource;
+
+ memcpy(p, buf, cplen);
+
+ if (cplen < PAGE_SIZE) {
+ /*
+ * We're done, with a length that wasn't page
+ * aligned, so possibly not word aligned. Pad
+ * any trailing bytes with 0.
+ */
+ xdr_encode_opaque_fixed(p, NULL, cplen);
+ break;
+ }
+
+ buflen -= PAGE_SIZE;
+ buf += PAGE_SIZE;
+ }
+
+ return 0;
+}
+
+static __be32
+nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+ struct nfsd4_getxattr *getxattr)
+{
+ struct xdr_stream *xdr = &resp->xdr;
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (!p)
+ return nfserr_resource;
+
+ *p = cpu_to_be32(getxattr->getxa_len);
+
+ if (getxattr->getxa_len == 0)
+ return 0;
+
+ return nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
+ getxattr->getxa_len);
+}
+
+static __be32
+nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+ struct nfsd4_setxattr *setxattr)
+{
+ struct xdr_stream *xdr = &resp->xdr;
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 20);
+ if (!p)
+ return nfserr_resource;
+
+ encode_cinfo(p, &setxattr->setxa_cinfo);
+
+ return 0;
+}
+
+/*
+ * See if there are cookie values that can be rejected outright.
+ */
+static __be32
+nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
+ u32 *offsetp)
+{
+ u64 cookie = listxattrs->lsxa_cookie;
+
+ /*
+ * If the cookie is larger than the maximum number we can fit
+ * in either the buffer we just got back from vfs_listxattr, or,
+ * XDR-encoded, in the return buffer, it's invalid.
+ */
+ if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
+ return nfserr_badcookie;
+
+ if (cookie > (listxattrs->lsxa_maxcount /
+ (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
+ return nfserr_badcookie;
+
+ *offsetp = (u32)cookie;
+ return 0;
+}
+
+static __be32
+nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
+ struct nfsd4_listxattrs *listxattrs)
+{
+ struct xdr_stream *xdr = &resp->xdr;
+ u32 cookie_offset, count_offset, eof;
+ u32 left, xdrleft, slen, count;
+ u32 xdrlen, offset;
+ u64 cookie;
+ char *sp;
+ __be32 status;
+ __be32 *p;
+ u32 nuser;
+
+ eof = 1;
+
+ status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
+ if (status)
+ return status;
+
+ /*
+ * Reserve space for the cookie and the name array count. Record
+ * the offsets to save them later.
+ */
+ cookie_offset = xdr->buf->len;
+ count_offset = cookie_offset + 8;
+ p = xdr_reserve_space(xdr, 12);
+ if (!p)
+ return nfserr_resource;
+
+ count = 0;
+ left = listxattrs->lsxa_len;
+ sp = listxattrs->lsxa_buf;
+ nuser = 0;
+
+ xdrleft = listxattrs->lsxa_maxcount;
+
+ while (left > 0 && xdrleft > 0) {
+ slen = strlen(sp);
+
+ /*
+ * Check if this a user. attribute, skip it if not.
+ */
+ if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
+ goto contloop;
+
+ slen -= XATTR_USER_PREFIX_LEN;
+ xdrlen = 4 + ((slen + 3) & ~3);
+ if (xdrlen > xdrleft) {
+ if (count == 0) {
+ /*
+ * Can't even fit the first attribute name.
+ */
+ return nfserr_toosmall;
+ }
+ eof = 0;
+ goto wreof;
+ }
+
+ left -= XATTR_USER_PREFIX_LEN;
+ sp += XATTR_USER_PREFIX_LEN;
+ if (nuser++ < offset)
+ goto contloop;
+
+
+ p = xdr_reserve_space(xdr, xdrlen);
+ if (!p)
+ return nfserr_resource;
+
+ p = xdr_encode_opaque(p, sp, slen);
+
+ xdrleft -= xdrlen;
+ count++;
+contloop:
+ sp += slen + 1;
+ left -= slen + 1;
+ }
+
+ /*
+ * If there were user attributes to copy, but we didn't copy
+ * any, the offset was too large (e.g. the cookie was invalid).
+ */
+ if (nuser > 0 && count == 0)
+ return nfserr_badcookie;
+
+wreof:
+ p = xdr_reserve_space(xdr, 4);
+ if (!p)
+ return nfserr_resource;
+ *p = cpu_to_be32(eof);
+
+ cookie = offset + count;
+
+ write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
+ count = htonl(count);
+ write_bytes_to_xdr_buf(xdr->buf, count_offset, &count, 4);
+ return 0;
+}
+
+static __be32
+nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+ struct nfsd4_removexattr *removexattr)
+{
+ struct xdr_stream *xdr = &resp->xdr;
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 20);
+ if (!p)
+ return nfserr_resource;
+
+ p = encode_cinfo(p, &removexattr->rmxa_cinfo);
+ return 0;
+}
+
typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
/*
@@ -4545,6 +4989,12 @@ static const nfsd4_enc nfsd4_enc_ops[] = {
[OP_SEEK] = (nfsd4_enc)nfsd4_encode_seek,
[OP_WRITE_SAME] = (nfsd4_enc)nfsd4_encode_noop,
[OP_CLONE] = (nfsd4_enc)nfsd4_encode_noop,
+
+ /* RFC 8276 extended atributes operations */
+ [OP_GETXATTR] = (nfsd4_enc)nfsd4_encode_getxattr,
+ [OP_SETXATTR] = (nfsd4_enc)nfsd4_encode_setxattr,
+ [OP_LISTXATTRS] = (nfsd4_enc)nfsd4_encode_listxattrs,
+ [OP_REMOVEXATTR] = (nfsd4_enc)nfsd4_encode_removexattr,
};
/*
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 350aeda0c48c..cbe50e452f19 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -165,7 +165,7 @@ Needs to be updated if more operations are defined in future.*/
#define FIRST_NFS4_OP OP_ACCESS
#define LAST_NFS40_OP OP_RELEASE_LOCKOWNER
#define LAST_NFS41_OP OP_RECLAIM_COMPLETE
-#define LAST_NFS42_OP OP_CLONE
+#define LAST_NFS42_OP OP_REMOVEXATTR
#define LAST_NFS4_OP LAST_NFS42_OP
enum nfsstat4 {
--
2.17.2
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