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@xxxxxxxxxx> cc: "Theodore Ts'o" <tytso@xxxxxxx> cc: Andreas Dilger <adilger.kernel@xxxxxxxxx> cc: linux-ext4@xxxxxxxxxxxxxxx --- 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 61b37a052052..f0304aa107f8 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> @@ -3190,6 +3191,11 @@ 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@xxxxxxxxxx) + */ + +#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 ff1b764b0c0e..3655fbeab754 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1487,6 +1487,9 @@ 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 150b693a1b5a..4cfb71227eff 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -42,6 +42,8 @@ #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. * @@ -323,4 +325,18 @@ 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 9f9564f7f73e..6ad1128a3e1d 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -384,6 +384,40 @@ 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; @@ -471,6 +505,7 @@ 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), {} };