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From: David Howells <dhowells@redhat.com>
To: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk
Cc: Theodore Ts'o <tytso@mit.edu>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	linux-ext4@vger.kernel.org, dhowells@redhat.com,
	raven@themaw.net, mszeredi@redhat.com, christian@brauner.io,
	jannh@google.com, darrick.wong@oracle.com, kzak@redhat.com,
	jlayton@redhat.com, linux-api@vger.kernel.org,
	linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 13/14] fsinfo: Example support for Ext4 [ver #18]
Date: Mon, 09 Mar 2020 14:02:46 +0000	[thread overview]
Message-ID: <158376256623.344135.9686051802633431404.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <158376244589.344135.12925590041630631412.stgit@warthog.procyon.org.uk>

Add the ability to list some Ext4 volume timestamps as an example.

Is this useful for ext4?  Is there anything else that could be useful?

Signed-off-by: David Howells <dhowells@redhat.com>
cc: "Theodore Ts'o" <tytso@mit.edu>
cc: Andreas Dilger <adilger.kernel@dilger.ca>
cc: linux-ext4@vger.kernel.org
---

 fs/ext4/Makefile            |    1 +
 fs/ext4/ext4.h              |    6 ++++++
 fs/ext4/fsinfo.c            |   45 +++++++++++++++++++++++++++++++++++++++++++
 fs/ext4/super.c             |    3 +++
 include/uapi/linux/fsinfo.h |   16 +++++++++++++++
 samples/vfs/test-fsinfo.c   |   35 +++++++++++++++++++++++++++++++++
 6 files changed, 106 insertions(+)
 create mode 100644 fs/ext4/fsinfo.c

diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 4ccb3c9189d8..71d5b460c7c7 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -16,3 +16,4 @@ ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o
 ext4-inode-test-objs			+= inode-test.o
 obj-$(CONFIG_EXT4_KUNIT_TESTS)		+= ext4-inode-test.o
 ext4-$(CONFIG_FS_VERITY)		+= verity.o
+ext4-$(CONFIG_FSINFO)			+= fsinfo.o
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9a2ee2428ecc..461968a87cd6 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -42,6 +42,7 @@
 
 #include <linux/fscrypt.h>
 #include <linux/fsverity.h>
+#include <linux/fsinfo.h>
 
 #include <linux/compiler.h>
 
@@ -3166,6 +3167,11 @@ extern const struct inode_operations ext4_file_inode_operations;
 extern const struct file_operations ext4_file_operations;
 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
 
+/* fsinfo.c */
+#ifdef CONFIG_FSINFO
+extern int ext4_fsinfo(struct path *path, struct fsinfo_context *ctx);
+#endif
+
 /* inline.c */
 extern int ext4_get_max_inline_size(struct inode *inode);
 extern int ext4_find_inline_data_nolock(struct inode *inode);
diff --git a/fs/ext4/fsinfo.c b/fs/ext4/fsinfo.c
new file mode 100644
index 000000000000..785f82a74dc9
--- /dev/null
+++ b/fs/ext4/fsinfo.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Filesystem information for ext4
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/mount.h>
+#include "ext4.h"
+
+static int ext4_fsinfo_get_volume_name(struct path *path, struct fsinfo_context *ctx)
+{
+	const struct ext4_sb_info *sbi = EXT4_SB(path->mnt->mnt_sb);
+	const struct ext4_super_block *es = sbi->s_es;
+
+	memcpy(ctx->buffer, es->s_volume_name, sizeof(es->s_volume_name));
+	return strlen(ctx->buffer);
+}
+
+static int ext4_fsinfo_get_timestamps(struct path *path, struct fsinfo_context *ctx)
+{
+	const struct ext4_sb_info *sbi = EXT4_SB(path->mnt->mnt_sb);
+	const struct ext4_super_block *es = sbi->s_es;
+	struct fsinfo_ext4_timestamps *ts = ctx->buffer;
+
+#define Z(R,S) R = S | (((u64)S##_hi) << 32)
+	Z(ts->mkfs_time,	es->s_mkfs_time);
+	Z(ts->mount_time,	es->s_mtime);
+	Z(ts->write_time,	es->s_wtime);
+	Z(ts->last_check_time,	es->s_lastcheck);
+	Z(ts->first_error_time,	es->s_first_error_time);
+	Z(ts->last_error_time,	es->s_last_error_time);
+	return sizeof(*ts);
+}
+
+static const struct fsinfo_attribute ext4_fsinfo_attributes[] = {
+	FSINFO_STRING	(FSINFO_ATTR_VOLUME_NAME,	ext4_fsinfo_get_volume_name),
+	FSINFO_VSTRUCT	(FSINFO_ATTR_EXT4_TIMESTAMPS,	ext4_fsinfo_get_timestamps),
+	{}
+};
+
+int ext4_fsinfo(struct path *path, struct fsinfo_context *ctx)
+{
+	return fsinfo_get_attribute(path, ctx, ext4_fsinfo_attributes);
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 8434217549b3..02b4df073c4b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1477,6 +1477,9 @@ static const struct super_operations ext4_sops = {
 	.freeze_fs	= ext4_freeze,
 	.unfreeze_fs	= ext4_unfreeze,
 	.statfs		= ext4_statfs,
+#ifdef CONFIG_FSINFO
+	.fsinfo		= ext4_fsinfo,
+#endif
 	.remount_fs	= ext4_remount,
 	.show_options	= ext4_show_options,
 #ifdef CONFIG_QUOTA
diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h
index 154c13a55819..d8d05f0f1473 100644
--- a/include/uapi/linux/fsinfo.h
+++ b/include/uapi/linux/fsinfo.h
@@ -41,6 +41,8 @@
 #define FSINFO_ATTR_AFS_SERVER_NAME	0x301	/* Name of the Nth server (string) */
 #define FSINFO_ATTR_AFS_SERVER_ADDRESSES 0x302	/* List of addresses of the Nth server */
 
+#define FSINFO_ATTR_EXT4_TIMESTAMPS	0x400	/* Ext4 superblock timestamps */
+
 /*
  * Optional fsinfo() parameter structure.
  *
@@ -312,4 +314,18 @@ struct fsinfo_afs_server_address {
 
 #define FSINFO_ATTR_AFS_SERVER_ADDRESSES__STRUCT struct fsinfo_afs_server_address
 
+/*
+ * Information struct for fsinfo(FSINFO_ATTR_EXT4_TIMESTAMPS).
+ */
+struct fsinfo_ext4_timestamps {
+	__u64		mkfs_time;
+	__u64		mount_time;
+	__u64		write_time;
+	__u64		last_check_time;
+	__u64		first_error_time;
+	__u64		last_error_time;
+};
+
+#define FSINFO_ATTR_EXT4_TIMESTAMPS__STRUCT struct fsinfo_ext4_timestamps
+
 #endif /* _UAPI_LINUX_FSINFO_H */
diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c
index 82944f09e0c9..829297e9d1b6 100644
--- a/samples/vfs/test-fsinfo.c
+++ b/samples/vfs/test-fsinfo.c
@@ -374,6 +374,40 @@ static void dump_afs_fsinfo_server_address(void *reply, unsigned int size)
 	printf("family=%u\n", ss->ss_family);
 }
 
+static char *dump_ext4_time(char *buffer, time_t tim)
+{
+	struct tm tm;
+	int len;
+
+	if (tim == 0)
+		return "-";
+
+	if (!localtime_r(&tim, &tm)) {
+		perror("localtime_r");
+		exit(1);
+	}
+	len = strftime(buffer, 100, "%F %T", &tm);
+	if (len == 0) {
+		perror("strftime");
+		exit(1);
+	}
+	return buffer;
+}
+
+static void dump_ext4_fsinfo_timestamps(void *reply, unsigned int size)
+{
+	struct fsinfo_ext4_timestamps *r = reply;
+	char buffer[100];
+
+	printf("\n");
+	printf("\tmkfs    : %s\n", dump_ext4_time(buffer, r->mkfs_time));
+	printf("\tmount   : %s\n", dump_ext4_time(buffer, r->mount_time));
+	printf("\twrite   : %s\n", dump_ext4_time(buffer, r->write_time));
+	printf("\tfsck    : %s\n", dump_ext4_time(buffer, r->last_check_time));
+	printf("\t1st-err : %s\n", dump_ext4_time(buffer, r->first_error_time));
+	printf("\tlast-err: %s\n", dump_ext4_time(buffer, r->last_error_time));
+}
+
 static void dump_string(void *reply, unsigned int size)
 {
 	char *s = reply, *p;
@@ -460,6 +494,7 @@ static const struct fsinfo_attribute fsinfo_attributes[] = {
 	FSINFO_STRING	(FSINFO_ATTR_AFS_CELL_NAME,	string),
 	FSINFO_STRING	(FSINFO_ATTR_AFS_SERVER_NAME,	string),
 	FSINFO_LIST_N	(FSINFO_ATTR_AFS_SERVER_ADDRESSES, afs_fsinfo_server_address),
+	FSINFO_VSTRUCT	(FSINFO_ATTR_EXT4_TIMESTAMPS,	ext4_fsinfo_timestamps),
 	{}
 };
 



  parent reply	other threads:[~2020-03-09 14:02 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-09 14:00 [PATCH 00/14] VFS: Filesystem information " David Howells
2020-03-09 14:00 ` [PATCH 01/14] VFS: Add additional RESOLVE_* flags " David Howells
2020-03-09 20:56   ` Stefan Metzmacher
2020-03-09 21:13   ` David Howells
2020-03-10  0:55   ` Aleksa Sarai
2020-03-10  1:14     ` Linus Torvalds
2020-03-10  7:25     ` David Howells
2020-03-11 17:59       ` Linus Torvalds
2020-03-12  9:08         ` Stefan Metzmacher
2020-03-12 16:24           ` Linus Torvalds
2020-03-12 17:11             ` Stefan Metzmacher
2020-03-12 19:37               ` Al Viro
2020-03-12 21:48               ` Jeremy Allison
2020-03-13  9:59               ` Aleksa Sarai
2020-03-13 10:00                 ` Aleksa Sarai
2020-03-13 16:48                 ` Jeremy Allison
2020-03-13 18:28                 ` Al Viro
2020-03-13 18:35                   ` Jeremy Allison
2020-03-16 14:21                   ` Aleksa Sarai
2020-03-16 14:20                     ` Aleksa Sarai
2020-03-12 19:25             ` Al Viro
2020-03-12 16:56           ` David Howells
2020-03-12 18:09             ` Linus Torvalds
2020-03-13  9:53               ` Aleksa Sarai
2020-03-13  9:50         ` Aleksa Sarai
2020-03-09 14:01 ` [PATCH 02/14] fsinfo: Add fsinfo() syscall to query filesystem information " David Howells
2020-03-10  9:31   ` Christian Brauner
2020-03-10  9:32     ` [PATCH v19 01/14] fsinfo: Add fsinfo() syscall to query filesystem information Christian Brauner
2020-03-10  9:32       ` [PATCH v19 14/14] arch: wire up fsinfo syscall Christian Brauner
2020-03-09 14:01 ` [PATCH 03/14] fsinfo: Provide a bitmap of supported features [ver #18] David Howells
2020-03-09 14:01 ` [PATCH 04/14] fsinfo: Allow retrieval of superblock devname, options and stats " David Howells
2020-03-09 14:01 ` [PATCH 05/14] fsinfo: Allow fsinfo() to look up a mount object by ID " David Howells
2020-03-09 14:01 ` [PATCH 06/14] fsinfo: Add a uniquifier ID to struct mount " David Howells
2020-03-09 14:01 ` [PATCH 07/14] fsinfo: Allow mount information to be queried " David Howells
2020-03-10  9:04   ` Miklos Szeredi
2020-03-09 14:02 ` [PATCH 08/14] fsinfo: Allow the mount topology propogation flags to be retrieved " David Howells
2020-03-10  8:42   ` Christian Brauner
2020-03-09 14:02 ` [PATCH 09/14] fsinfo: Provide notification overrun handling support " David Howells
2020-03-09 14:02 ` [PATCH 10/14] fsinfo: sample: Mount listing program " David Howells
2020-03-09 14:02 ` [PATCH 11/14] fsinfo: Add API documentation " David Howells
2020-03-09 14:02 ` [PATCH 12/14] fsinfo: Add support for AFS " David Howells
2020-03-09 14:02 ` David Howells [this message]
2020-03-09 14:02 ` [PATCH 14/14] fsinfo: Example support for NFS " David Howells
2020-03-09 17:50 ` [PATCH 00/14] VFS: Filesystem information " Jeff Layton
2020-03-09 19:22   ` Andres Freund
2020-03-09 22:49     ` Jeff Layton
2020-03-10  0:18       ` Andres Freund
2020-03-09 20:02 ` Miklos Szeredi
2020-03-09 22:52 ` David Howells
2020-03-10  9:18   ` Miklos Szeredi

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