[PATCH v2 11/13] NFSv4.2: add the extended attribute proc functions.

Frank van der Linden
2020-03-25T23:10:59Z

Implement the extended attribute procedures for NFSv4.2 extended
attribute support (RFC 8276).

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
---
fs/nfs/nfs42.h | 8 ++
fs/nfs/nfs42proc.c | 236 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 244 insertions(+)

diff --git a/fs/nfs/nfs42.h b/fs/nfs/nfs42.h
index 51de8ddc7d88..0fe5aacbcfdf 100644
--- a/fs/nfs/nfs42.h
+++ b/fs/nfs/nfs42.h
@@ -39,6 +39,14 @@ static inline bool nfs42_files_from_same_server(struct file *in,
c_out->cl_serverowner);
}

+ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name,
+ void *buf, size_t buflen);
+int nfs42_proc_setxattr(struct inode *inode, const char *name,
+ const void *buf, size_t buflen, int flags);
+ssize_t nfs42_proc_listxattrs(struct inode *inode, void *buf,
+ size_t buflen, u64 *cookiep, bool *eofp);
+int nfs42_proc_removexattr(struct inode *inode, const char *name);
+
/*
* Maximum XDR buffer size needed for a listxattr buffer of buflen size.
*
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index e2ae54b35dfe..8c2e52bc986a 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -1088,3 +1088,239 @@ int nfs42_proc_clone(struct file *src_f, struct file *dst_f,
nfs_put_lock_context(src_lock);
return err;
}
+
+#define NFS4XATTR_MAXPAGES DIV_ROUND_UP(XATTR_SIZE_MAX, PAGE_SIZE)
+
+static int _nfs42_proc_removexattr(struct inode *inode, const char *name)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct nfs42_removexattrargs args = {
+ .fh = NFS_FH(inode),
+ .xattr_name = name,
+ };
+ struct nfs42_removexattrres res;
+ struct rpc_message msg = {
+ .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVEXATTR],
+ .rpc_argp = &args,
+ .rpc_resp = &res,
+ };
+ int ret;
+ unsigned long timestamp = jiffies;
+
+ ret = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
+ &res.seq_res, 1);
+ if (!ret)
+ nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
+
+ return ret;
+}
+
+static int _nfs42_proc_setxattr(struct inode *inode, const char *name,
+ const void *buf, size_t buflen, int flags)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct page *pages[NFS4XATTR_MAXPAGES];
+ struct nfs42_setxattrargs arg = {
+ .fh = NFS_FH(inode),
+ .xattr_pages = pages,
+ .xattr_len = buflen,
+ .xattr_name = name,
+ .xattr_flags = flags,
+ };
+ struct nfs42_setxattrres res;
+ struct rpc_message msg = {
+ .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETXATTR],
+ .rpc_argp = &arg,
+ .rpc_resp = &res,
+ };
+ int ret, np;
+ unsigned long timestamp = jiffies;
+
+ if (buflen > server->sxasize)
+ return -ERANGE;
+
+ if (buflen > 0) {
+ np = nfs4_buf_to_pages_noslab(buf, buflen, arg.xattr_pages);
+ if (np < 0)
+ return np;
+ } else
+ np = 0;
+
+ ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
+ &res.seq_res, 1);
+
+ for (; np > 0; np--)
+ put_page(pages[np - 1]);
+
+ if (!ret)
+ nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
+
+ return ret;
+}
+
+static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name,
+ void *buf, size_t buflen)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct page *pages[NFS4XATTR_MAXPAGES] = {};
+ struct nfs42_getxattrargs arg = {
+ .fh = NFS_FH(inode),
+ .xattr_pages = pages,
+ .xattr_len = buflen,
+ .xattr_name = name,
+ };
+ struct nfs42_getxattrres res;
+ struct rpc_message msg = {
+ .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETXATTR],
+ .rpc_argp = &arg,
+ .rpc_resp = &res,
+ };
+ int ret, np;
+
+ ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
+ &res.seq_res, 0);
+ if (ret < 0)
+ return ret;
+
+ if (buflen) {
+ if (res.xattr_len > buflen)
+ return -ERANGE;
+ _copy_from_pages(buf, pages, 0, res.xattr_len);
+ }
+
+ np = DIV_ROUND_UP(res.xattr_len, PAGE_SIZE);
+ while (--np >= 0)
+ __free_page(pages[np]);
+
+ return res.xattr_len;
+}
+
+static ssize_t _nfs42_proc_listxattrs(struct inode *inode, void *buf,
+ size_t buflen, u64 *cookiep, bool *eofp)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct page **pages;
+ struct nfs42_listxattrsargs arg = {
+ .fh = NFS_FH(inode),
+ .cookie = *cookiep,
+ };
+ struct nfs42_listxattrsres res = {
+ .eof = false,
+ .xattr_buf = buf,
+ .xattr_len = buflen,
+ };
+ struct rpc_message msg = {
+ .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LISTXATTRS],
+ .rpc_argp = &arg,
+ .rpc_resp = &res,
+ };
+ u32 xdrlen;
+ int ret, np;
+
+
+ res.scratch = alloc_page(GFP_KERNEL);
+ if (!res.scratch)
+ return -ENOMEM;
+
+ xdrlen = nfs42_listxattr_xdrsize(buflen);
+ if (xdrlen > server->lxasize)
+ xdrlen = server->lxasize;
+ np = xdrlen / PAGE_SIZE + 1;
+
+ pages = kcalloc(np, sizeof(struct page *), GFP_KERNEL);
+ if (pages == NULL) {
+ __free_page(res.scratch);
+ return -ENOMEM;
+ }
+
+ arg.xattr_pages = pages;
+ arg.count = xdrlen;
+
+ ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
+ &res.seq_res, 0);
+
+ if (ret >= 0) {
+ ret = res.copied;
+ *cookiep = res.cookie;
+ *eofp = res.eof;
+ }
+
+ while (--np >= 0) {
+ if (pages[np])
+ __free_page(pages[np]);
+ }
+
+ __free_page(res.scratch);
+ kfree(pages);
+
+ return ret;
+
+}
+
+ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name,
+ void *buf, size_t buflen)
+{
+ struct nfs4_exception exception = { };
+ ssize_t err;
+
+ do {
+ err = _nfs42_proc_getxattr(inode, name, buf, buflen);
+ if (err >= 0)
+ break;
+ err = nfs4_handle_exception(NFS_SERVER(inode), err,
+ &exception);
+ } while (exception.retry);
+
+ return err;
+}
+
+int nfs42_proc_setxattr(struct inode *inode, const char *name,
+ const void *buf, size_t buflen, int flags)
+{
+ struct nfs4_exception exception = { };
+ int err;
+
+ do {
+ err = _nfs42_proc_setxattr(inode, name, buf, buflen, flags);
+ if (!err)
+ break;
+ err = nfs4_handle_exception(NFS_SERVER(inode), err,
+ &exception);
+ } while (exception.retry);
+
+ return err;
+}
+
+ssize_t nfs42_proc_listxattrs(struct inode *inode, void *buf,
+ size_t buflen, u64 *cookiep, bool *eofp)
+{
+ struct nfs4_exception exception = { };
+ ssize_t err;
+
+ do {
+ err = _nfs42_proc_listxattrs(inode, buf, buflen,
+ cookiep, eofp);
+ if (err >= 0)
+ break;
+ err = nfs4_handle_exception(NFS_SERVER(inode), err,
+ &exception);
+ } while (exception.retry);
+
+ return err;
+}
+
+int nfs42_proc_removexattr(struct inode *inode, const char *name)
+{
+ struct nfs4_exception exception = { };
+ int err;
+
+ do {
+ err = _nfs42_proc_removexattr(inode, name);
+ if (!err)
+ break;
+ err = nfs4_handle_exception(NFS_SERVER(inode), err,
+ &exception);
+ } while (exception.retry);
+
+ return err;
+}
--
2.17.2