lkml.org 
[lkml]   [2020]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH 13/14] fsinfo: Example support for Ext4 [ver #18]
    From
    Date
    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),
    {}
    };


    \
     
     \ /
      Last update: 2020-03-09 15:03    [W:3.646 / U:0.600 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site