[PATCH 17/17] fsinfo: Add example support for NFS [ver #17]

David Howells
2020-02-21T18:04:16Z

Add the ability to list NFS server addresses and hostname, timestamp
information and capabilities as an example.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-nfs@vger.kernel.org
---

fs/nfs/Makefile | 1
fs/nfs/fsinfo.c | 230 ++++++++++++++++++++++++++++++++++++++++++
fs/nfs/internal.h | 6 +
fs/nfs/nfs4super.c | 3 +
fs/nfs/super.c | 3 +
include/uapi/linux/fsinfo.h | 29 +++++
include/uapi/linux/windows.h | 35 ++++++
samples/vfs/test-fsinfo.c | 40 +++++++
8 files changed, 347 insertions(+)
create mode 100644 fs/nfs/fsinfo.c
create mode 100644 include/uapi/linux/windows.h

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index 2433c3e03cfa..20fbc9596833 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -13,6 +13,7 @@ nfs-y := client.o dir.o file.o getroot.o inode.o super.o \
nfs-$(CONFIG_ROOT_NFS) += nfsroot.o
nfs-$(CONFIG_SYSCTL) += sysctl.o
nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o
+nfs-$(CONFIG_FSINFO) += fsinfo.o

obj-$(CONFIG_NFS_V2) += nfsv2.o
nfsv2-y := nfs2super.o proc.o nfs2xdr.o
diff --git a/fs/nfs/fsinfo.c b/fs/nfs/fsinfo.c
new file mode 100644
index 000000000000..a0299ec27efd
--- /dev/null
+++ b/fs/nfs/fsinfo.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Filesystem information for NFS
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/windows.h>
+#include "internal.h"
+
+static const struct fsinfo_timestamp_info nfs_timestamp_info = {
+ .atime = {
+ .minimum = 0,
+ .maximum = UINT_MAX,
+ .gran_mantissa = 1,
+ .gran_exponent = 0,
+ },
+ .mtime = {
+ .minimum = 0,
+ .maximum = UINT_MAX,
+ .gran_mantissa = 1,
+ .gran_exponent = 0,
+ },
+ .ctime = {
+ .minimum = 0,
+ .maximum = UINT_MAX,
+ .gran_mantissa = 1,
+ .gran_exponent = 0,
+ },
+ .btime = {
+ .minimum = 0,
+ .maximum = UINT_MAX,
+ .gran_mantissa = 1,
+ .gran_exponent = 0,
+ },
+};
+
+static int nfs_fsinfo_get_timestamp_info(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ struct fsinfo_timestamp_info *r = ctx->buffer;
+ unsigned long long nsec;
+ unsigned int rem, mant;
+ int exp = -9;
+
+ *r = nfs_timestamp_info;
+
+ nsec = server->time_delta.tv_nsec;
+ nsec += server->time_delta.tv_sec * 1000000000ULL;
+ if (nsec == 0)
+ goto out;
+
+ do {
+ mant = nsec;
+ rem = do_div(nsec, 10);
+ if (rem)
+ break;
+ exp++;
+ } while (nsec);
+
+ r->atime.gran_mantissa = mant;
+ r->atime.gran_exponent = exp;
+ r->btime.gran_mantissa = mant;
+ r->btime.gran_exponent = exp;
+ r->ctime.gran_mantissa = mant;
+ r->ctime.gran_exponent = exp;
+ r->mtime.gran_mantissa = mant;
+ r->mtime.gran_exponent = exp;
+
+out:
+ return sizeof(*r);
+}
+
+static int nfs_fsinfo_get_info(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ const struct nfs_client *clp = server->nfs_client;
+ struct fsinfo_nfs_info *r = ctx->buffer;
+
+ r->version = clp->rpc_ops->version;
+ r->minor_version = clp->cl_minorversion;
+ r->transport_proto = clp->cl_proto;
+ return sizeof(*r);
+}
+
+static int nfs_fsinfo_get_server_name(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ const struct nfs_client *clp = server->nfs_client;
+
+ return fsinfo_string(clp->cl_hostname, ctx);
+}
+
+static int nfs_fsinfo_get_server_addresses(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ const struct nfs_client *clp = server->nfs_client;
+ struct fsinfo_nfs_server_address *addr = ctx->buffer;
+ int ret;
+
+ ret = 1 * sizeof(*addr);
+ if (ret <= ctx->buf_size)
+ memcpy(&addr[0].address, &clp->cl_addr, clp->cl_addrlen);
+ return ret;
+
+}
+
+static int nfs_fsinfo_get_gssapi_name(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ const struct nfs_client *clp = server->nfs_client;
+
+ return fsinfo_string(clp->cl_acceptor, ctx);
+}
+
+static int nfs_fsinfo_get_limits(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ struct fsinfo_limits *lim = ctx->buffer;
+
+ lim->max_file_size.hi = 0;
+ lim->max_file_size.lo = server->maxfilesize;
+ lim->max_ino.hi = 0;
+ lim->max_ino.lo = U64_MAX;
+ lim->max_hard_links = UINT_MAX;
+ lim->max_uid = UINT_MAX;
+ lim->max_gid = UINT_MAX;
+ lim->max_filename_len = NAME_MAX - 1;
+ lim->max_symlink_len = PATH_MAX - 1;
+ return sizeof(*lim);
+}
+
+static int nfs_fsinfo_get_supports(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ struct fsinfo_supports *sup = ctx->buffer;
+
+ /* Don't set STATX_INO as i_ino is fabricated and may not be unique. */
+
+ if (!(server->caps & NFS_CAP_MODE))
+ sup->stx_mask |= STATX_TYPE | STATX_MODE;
+ if (server->caps & NFS_CAP_OWNER)
+ sup->stx_mask |= STATX_UID;
+ if (server->caps & NFS_CAP_OWNER_GROUP)
+ sup->stx_mask |= STATX_GID;
+ if (server->caps & NFS_CAP_ATIME)
+ sup->stx_mask |= STATX_ATIME;
+ if (server->caps & NFS_CAP_CTIME)
+ sup->stx_mask |= STATX_CTIME;
+ if (server->caps & NFS_CAP_MTIME)
+ sup->stx_mask |= STATX_MTIME;
+ if (server->attr_bitmask[0] & FATTR4_WORD0_SIZE)
+ sup->stx_mask |= STATX_SIZE;
+ if (server->attr_bitmask[1] & FATTR4_WORD1_NUMLINKS)
+ sup->stx_mask |= STATX_NLINK;
+
+ if (server->attr_bitmask[0] & FATTR4_WORD0_ARCHIVE)
+ sup->win_file_attrs |= ATTR_ARCHIVE;
+ if (server->attr_bitmask[0] & FATTR4_WORD0_HIDDEN)
+ sup->win_file_attrs |= ATTR_HIDDEN;
+ if (server->attr_bitmask[1] & FATTR4_WORD1_SYSTEM)
+ sup->win_file_attrs |= ATTR_SYSTEM;
+
+ sup->stx_attributes = STATX_ATTR_AUTOMOUNT;
+ return sizeof(*sup);
+}
+
+static int nfs_fsinfo_get_features(struct path *path, struct fsinfo_context *ctx)
+{
+ const struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+ struct fsinfo_features *ft = ctx->buffer;
+
+ fsinfo_set_feature(ft, FSINFO_FEAT_IS_NETWORK_FS);
+ fsinfo_set_feature(ft, FSINFO_FEAT_AUTOMOUNTS);
+ fsinfo_set_feature(ft, FSINFO_FEAT_O_SYNC);
+ fsinfo_set_feature(ft, FSINFO_FEAT_O_DIRECT);
+ fsinfo_set_feature(ft, FSINFO_FEAT_ADV_LOCKS);
+ fsinfo_set_feature(ft, FSINFO_FEAT_DEVICE_FILES);
+ fsinfo_set_feature(ft, FSINFO_FEAT_UNIX_SPECIALS);
+ if (server->nfs_client->rpc_ops->version == 4) {
+ fsinfo_set_feature(ft, FSINFO_FEAT_LEASES);
+ fsinfo_set_feature(ft, FSINFO_FEAT_IVER_ALL_CHANGE);
+ }
+
+ if (server->caps & NFS_CAP_OWNER)
+ fsinfo_set_feature(ft, FSINFO_FEAT_UIDS);
+ if (server->caps & NFS_CAP_OWNER_GROUP)
+ fsinfo_set_feature(ft, FSINFO_FEAT_GIDS);
+ if (!(server->caps & NFS_CAP_MODE))
+ fsinfo_set_feature(ft, FSINFO_FEAT_NO_UNIX_MODE);
+ if (server->caps & NFS_CAP_ACLS)
+ fsinfo_set_feature(ft, FSINFO_FEAT_HAS_ACL);
+ if (server->caps & NFS_CAP_SYMLINKS)
+ fsinfo_set_feature(ft, FSINFO_FEAT_SYMLINKS);
+ if (server->caps & NFS_CAP_HARDLINKS)
+ fsinfo_set_feature(ft, FSINFO_FEAT_HARD_LINKS);
+ if (server->caps & NFS_CAP_ATIME)
+ fsinfo_set_feature(ft, FSINFO_FEAT_HAS_ATIME);
+ if (server->caps & NFS_CAP_CTIME)
+ fsinfo_set_feature(ft, FSINFO_FEAT_HAS_CTIME);
+ if (server->caps & NFS_CAP_MTIME)
+ fsinfo_set_feature(ft, FSINFO_FEAT_HAS_MTIME);
+
+ if (server->attr_bitmask[0] & FATTR4_WORD0_CASE_INSENSITIVE)
+ fsinfo_set_feature(ft, FSINFO_FEAT_NAME_CASE_INDEP);
+ if ((server->attr_bitmask[0] & FATTR4_WORD0_ARCHIVE) ||
+ (server->attr_bitmask[0] & FATTR4_WORD0_HIDDEN) ||
+ (server->attr_bitmask[1] & FATTR4_WORD1_SYSTEM))
+ fsinfo_set_feature(ft, FSINFO_FEAT_WINDOWS_ATTRS);
+
+ return sizeof(*ft);
+}
+
+static const struct fsinfo_attribute nfs_fsinfo_attributes[] = {
+ FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, nfs_fsinfo_get_timestamp_info),
+ FSINFO_VSTRUCT (FSINFO_ATTR_LIMITS, nfs_fsinfo_get_limits),
+ FSINFO_VSTRUCT (FSINFO_ATTR_SUPPORTS, nfs_fsinfo_get_supports),
+ FSINFO_VSTRUCT (FSINFO_ATTR_FEATURES, nfs_fsinfo_get_features),
+ FSINFO_VSTRUCT (FSINFO_ATTR_NFS_INFO, nfs_fsinfo_get_info),
+ FSINFO_STRING (FSINFO_ATTR_NFS_SERVER_NAME, nfs_fsinfo_get_server_name),
+ FSINFO_LIST (FSINFO_ATTR_NFS_SERVER_ADDRESSES, nfs_fsinfo_get_server_addresses),
+ FSINFO_STRING (FSINFO_ATTR_NFS_GSSAPI_NAME, nfs_fsinfo_get_gssapi_name),
+ {}
+};
+
+int nfs_fsinfo(struct path *path, struct fsinfo_context *ctx)
+{
+ return fsinfo_get_attribute(path, ctx, nfs_fsinfo_attributes);
+}
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index f80c47d5ff27..59e407066b45 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -10,6 +10,7 @@
#include <linux/sunrpc/addr.h>
#include <linux/nfs_page.h>
#include <linux/wait_bit.h>
+#include <linux/fsinfo.h>

#define NFS_SB_MASK (SB_RDONLY|SB_NOSUID|SB_NODEV|SB_NOEXEC|SB_SYNCHRONOUS)

@@ -247,6 +248,11 @@ extern const struct svc_version nfs4_callback_version4;
/* fs_context.c */
extern struct file_system_type nfs_fs_type;

+/* fsinfo.c */
+#ifdef CONFIG_FSINFO
+extern int nfs_fsinfo(struct path *path, struct fsinfo_context *ctx);
+#endif
+
/* pagelist.c */
extern int __init nfs_init_nfspagecache(void);
extern void nfs_destroy_nfspagecache(void);
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index 1475f932d7da..cd38da87cbd3 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -26,6 +26,9 @@ static const struct super_operations nfs4_sops = {
.write_inode = nfs4_write_inode,
.drop_inode = nfs_drop_inode,
.statfs = nfs_statfs,
+#ifdef CONFIG_FSINFO
+ .fsinfo = nfs_fsinfo,
+#endif
.evict_inode = nfs4_evict_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index dada09b391c6..27ac751d3789 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -76,6 +76,9 @@ const struct super_operations nfs_sops = {
.write_inode = nfs_write_inode,
.drop_inode = nfs_drop_inode,
.statfs = nfs_statfs,
+#ifdef CONFIG_FSINFO
+ .fsinfo = nfs_fsinfo,
+#endif
.evict_inode = nfs_evict_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h
index 6a8a7a8e4910..d5c4fe681333 100644
--- a/include/uapi/linux/fsinfo.h
+++ b/include/uapi/linux/fsinfo.h
@@ -39,6 +39,11 @@

#define FSINFO_ATTR_EXT4_TIMESTAMPS 0x400 /* Ext4 superblock timestamps */

+#define FSINFO_ATTR_NFS_INFO 0x500 /* Information about an NFS mount */
+#define FSINFO_ATTR_NFS_SERVER_NAME 0x501 /* Name of the server (string) */
+#define FSINFO_ATTR_NFS_SERVER_ADDRESSES 0x502 /* List of addresses of the server */
+#define FSINFO_ATTR_NFS_GSSAPI_NAME 0x503 /* GSSAPI acceptor name */
+
/*
* Optional fsinfo() parameter structure.
*
@@ -329,4 +334,28 @@ struct fsinfo_ext4_timestamps {

#define FSINFO_ATTR_EXT4_TIMESTAMPS__STRUCT struct fsinfo_ext4_timestamps

+/*
+ * Information struct for fsinfo(FSINFO_ATTR_NFS_INFO).
+ *
+ * Get information about an NFS mount.
+ */
+struct fsinfo_nfs_info {
+ __u32 version;
+ __u32 minor_version;
+ __u32 transport_proto;
+};
+
+#define FSINFO_ATTR_NFS_INFO__STRUCT struct fsinfo_nfs_info
+
+/*
+ * Information struct for fsinfo(FSINFO_ATTR_NFS_SERVER_ADDRESSES).
+ *
+ * Get the addresses of the server for an NFS mount.
+ */
+struct fsinfo_nfs_server_address {
+ struct __kernel_sockaddr_storage address;
+};
+
+#define FSINFO_ATTR_NFS_SERVER_ADDRESSES__STRUCT struct fsinfo_nfs_server_address
+
#endif /* _UAPI_LINUX_FSINFO_H */
diff --git a/include/uapi/linux/windows.h b/include/uapi/linux/windows.h
new file mode 100644
index 000000000000..17efb9a40529
--- /dev/null
+++ b/include/uapi/linux/windows.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Common windows attributes
+ */
+#ifndef _UAPI_LINUX_WINDOWS_H
+#define _UAPI_LINUX_WINDOWS_H
+
+/*
+ * File Attribute flags
+ */
+#define ATTR_READONLY 0x0001
+#define ATTR_HIDDEN 0x0002
+#define ATTR_SYSTEM 0x0004
+#define ATTR_VOLUME 0x0008
+#define ATTR_DIRECTORY 0x0010
+#define ATTR_ARCHIVE 0x0020
+#define ATTR_DEVICE 0x0040
+#define ATTR_NORMAL 0x0080
+#define ATTR_TEMPORARY 0x0100
+#define ATTR_SPARSE 0x0200
+#define ATTR_REPARSE 0x0400
+#define ATTR_COMPRESSED 0x0800
+#define ATTR_OFFLINE 0x1000 /* ie file not immediately available -
+ on offline storage */
+#define ATTR_NOT_CONTENT_INDEXED 0x2000
+#define ATTR_ENCRYPTED 0x4000
+#define ATTR_POSIX_SEMANTICS 0x01000000
+#define ATTR_BACKUP_SEMANTICS 0x02000000
+#define ATTR_DELETE_ON_CLOSE 0x04000000
+#define ATTR_SEQUENTIAL_SCAN 0x08000000
+#define ATTR_RANDOM_ACCESS 0x10000000
+#define ATTR_NO_BUFFERING 0x20000000
+#define ATTR_WRITE_THROUGH 0x80000000
+
+#endif /* _UAPI_LINUX_WINDOWS_H */
diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c
index df8d2449fc22..87239f0b6a50 100644
--- a/samples/vfs/test-fsinfo.c
+++ b/samples/vfs/test-fsinfo.c
@@ -391,6 +391,40 @@ static void dump_ext4_fsinfo_timestamps(void *reply, unsigned int size)
printf("\tlast-err: %s\n", dump_ext4_time(buffer, r->last_error_time));
}

+static void dump_nfs_fsinfo_info(void *reply, unsigned int size)
+{
+ struct fsinfo_nfs_info *r = reply;
+
+ printf("ver=%u.%u proto=%u\n", r->version, r->minor_version, r->transport_proto);
+}
+
+static void dump_nfs_fsinfo_server_addresses(void *reply, unsigned int size)
+{
+ struct fsinfo_nfs_server_address *r = reply;
+ struct sockaddr_storage *ss = (struct sockaddr_storage *)&r->address;
+ struct sockaddr_in6 *sin6;
+ struct sockaddr_in *sin;
+ char buf[1024];
+
+ switch (ss->ss_family) {
+ case AF_INET:
+ sin = (struct sockaddr_in *)ss;
+ if (!inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)))
+ break;
+ printf("%5u %s\n", ntohs(sin->sin_port), buf);
+ return;
+ case AF_INET6:
+ sin6 = (struct sockaddr_in6 *)ss;
+ if (!inet_ntop(AF_INET6, &sin6->sin6_addr, buf, sizeof(buf)))
+ break;
+ printf("%5u %s\n", ntohs(sin6->sin6_port), buf);
+ return;
+ default:
+ printf("family=%u\n", ss->ss_family);
+ return;
+ }
+}
+
static void dump_string(void *reply, unsigned int size)
{
char *s = reply, *p;
@@ -422,6 +456,8 @@ static void dump_string(void *reply, unsigned int size)
#define dump_fsinfo_generic_mount_point dump_string
#define dump_afs_cell_name dump_string
#define dump_afs_server_name dump_string
+#define dump_nfs_fsinfo_server_name dump_string
+#define dump_nfs_fsinfo_gssapi_name dump_string

/*
*
@@ -468,6 +504,10 @@ static const struct fsinfo_attribute fsinfo_attributes[] = {
FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, afs_server_name),
FSINFO_LIST_N (FSINFO_ATTR_AFS_SERVER_ADDRESSES, afs_fsinfo_server_address),
FSINFO_VSTRUCT (FSINFO_ATTR_EXT4_TIMESTAMPS, ext4_fsinfo_timestamps),
+ FSINFO_VSTRUCT (FSINFO_ATTR_NFS_INFO, nfs_fsinfo_info),
+ FSINFO_STRING (FSINFO_ATTR_NFS_SERVER_NAME, nfs_fsinfo_server_name),
+ FSINFO_LIST (FSINFO_ATTR_NFS_SERVER_ADDRESSES, nfs_fsinfo_server_addresses),
+ FSINFO_STRING (FSINFO_ATTR_NFS_GSSAPI_NAME, nfs_fsinfo_gssapi_name),
{}
};