Re: [PATCH v2] commands: add new stat command

[Sascha Hauer <sha@pengutronix.de>]

On Wed, Oct 26, 2022 at 08:38:19AM +0200, Ahmad Fatoum wrote:
> We have a couple of commands to help with debugging the VFS:
> ll, devinfo, devlookup, but we lack a command that can just dump all
> information we have in a struct stat or struct cdev. Add stat as such a
> command. For most uses, it's not needed, but it can come in handy for
> development. The stat_print and cdev_print functions underlying it are
> exported, so they can called for debugging purposes.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> v1 -> v2:
>   - support non absolute paths, e.g. dev/mmc0 (Sascha)
>   - use lstat by default (Sascha)
> ---

Applied, thanks

Sascha

>  commands/Kconfig  |  14 +++++++
>  commands/Makefile |   1 +
>  commands/stat.c   |  62 +++++++++++++++++++++++++++
>  fs/fs.c           | 105 +++++++++++++++++++++++++++++++++++++++++++++-
>  include/fs.h      |   3 ++
>  5 files changed, 184 insertions(+), 1 deletion(-)
>  create mode 100644 commands/stat.c
> 
> diff --git a/commands/Kconfig b/commands/Kconfig
> index 9894ecb9aa31..2ce990b5616a 100644
> --- a/commands/Kconfig
> +++ b/commands/Kconfig
> @@ -947,6 +947,20 @@ config CMD_LS
>  		  -C	column format (opposite of long format)
>  		  -R	list subdirectories recursively
>  
> +config CMD_STAT
> +	tristate
> +	prompt "stat"
> +	select PRINTF_UUID
> +	help
> +	  Display file status
> +
> +	  Usage: stat [-L] [FILEDIR...]
> +
> +	  Display status information about the specified files or directories.
> +
> +	  Options:
> +		  -L	follow symlinks
> +
>  config CMD_MD5SUM
>  	tristate
>  	select COMPILE_HASH
> diff --git a/commands/Makefile b/commands/Makefile
> index 068fbb32dad7..68d0d05365a5 100644
> --- a/commands/Makefile
> +++ b/commands/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_CMD_POWEROFF)	+= poweroff.o
>  obj-$(CONFIG_CMD_GO)		+= go.o
>  obj-$(CONFIG_CMD_PARTITION)	+= partition.o
>  obj-$(CONFIG_CMD_LS)		+= ls.o
> +obj-$(CONFIG_CMD_STAT)		+= stat.o
>  obj-$(CONFIG_CMD_CD)		+= cd.o
>  obj-$(CONFIG_CMD_PWD)		+= pwd.o
>  obj-$(CONFIG_CMD_MKDIR)		+= mkdir.o
> diff --git a/commands/stat.c b/commands/stat.c
> new file mode 100644
> index 000000000000..153eac50f1fa
> --- /dev/null
> +++ b/commands/stat.c
> @@ -0,0 +1,62 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +// SPDX-FileCopyrightText: © 2022 Ahmad Fatoum, Pengutronix
> +
> +#include <common.h>
> +#include <command.h>
> +#include <fs.h>
> +#include <linux/stat.h>
> +#include <errno.h>
> +#include <malloc.h>
> +#include <getopt.h>
> +#include <stringlist.h>
> +
> +static int do_stat(int argc, char *argv[])
> +{
> +	int (*statfn)(const char *, struct stat *) = lstat;
> +	int ret, opt, exitcode = 0;
> +	char **filename;
> +	struct stat st;
> +
> +	while((opt = getopt(argc, argv, "L")) > 0) {
> +		switch(opt) {
> +		case 'L':
> +			statfn = stat;
> +			break;
> +		default:
> +			return COMMAND_ERROR_USAGE;
> +		}
> +	}
> +
> +	if (optind == argc)
> +		return COMMAND_ERROR_USAGE;
> +
> +	for (filename = &argv[optind]; *filename; filename++) {
> +		ret = statfn(*filename, &st);
> +
> +		if (ret) {
> +			printf("%s: %s: %m\n", argv[0], *filename);
> +			exitcode = COMMAND_ERROR;
> +			continue;
> +		}
> +
> +		stat_print(*filename, &st);
> +	}
> +
> +	return exitcode;
> +}
> +
> +BAREBOX_CMD_HELP_START(stat)
> +BAREBOX_CMD_HELP_TEXT("Display status information about the specified files")
> +BAREBOX_CMD_HELP_TEXT("or directories.")
> +BAREBOX_CMD_HELP_TEXT("")
> +BAREBOX_CMD_HELP_TEXT("Options:")
> +BAREBOX_CMD_HELP_OPT ("-L",  "follow links")
> +BAREBOX_CMD_HELP_END
> +
> +BAREBOX_CMD_START(stat)
> +	.cmd		= do_stat,
> +	BAREBOX_CMD_DESC("display file status")
> +	BAREBOX_CMD_OPTS("[-L] [FILEDIR...]")
> +	BAREBOX_CMD_GROUP(CMD_GRP_FILE)
> +	BAREBOX_CMD_HELP(cmd_stat_help)
> +BAREBOX_CMD_END
> diff --git a/fs/fs.c b/fs/fs.c
> index 24a33195440f..8f214204947a 100644
> --- a/fs/fs.c
> +++ b/fs/fs.c
> @@ -67,6 +67,110 @@ char *mkmodestr(unsigned long mode, char *str)
>  }
>  EXPORT_SYMBOL(mkmodestr);
>  
> +void cdev_print(const struct cdev *cdev)
> +{
> +	bool uuid_set;
> +
> +	if (cdev->dev || cdev->master || cdev->partname) {
> +		printf("Origin: %s", dev_name(cdev->dev) ?: "None");
> +		if (cdev->master)
> +			printf("\tMaster: %s", cdev->master->name);
> +		if (cdev->partname)
> +			printf("\tPartition: %s", cdev->partname);
> +		printf("\n");
> +	}
> +	printf("Ocount: %d\tFlags: 0x%02x", cdev->open, cdev->flags);
> +	if (cdev->flags) {
> +		printf(" (");
> +		if (cdev->flags & DEVFS_IS_CHARACTER_DEV)
> +			printf(" cdev");
> +		if (cdev->flags & DEVFS_PARTITION_FIXED)
> +			printf(" fixed-partition");
> +		if (cdev->flags & DEVFS_PARTITION_READONLY)
> +			printf(" readonly-partition");
> +		if (cdev->flags & DEVFS_PARTITION_FROM_TABLE)
> +			printf(" table-partition");
> +		if (cdev->flags & DEVFS_IS_MCI_MAIN_PART_DEV)
> +			printf(" mci-main-partition");
> +		if (cdev->mtd)
> +			printf(" mtd");
> +		printf(" )");
> +	}
> +	printf("\n");
> +
> +	uuid_set = memchr_inv(cdev->uuid, 0x00 ,sizeof(cdev->uuid));
> +	if (cdev->filetype || cdev->dos_partition_type || uuid_set) {
> +		if (cdev->filetype)
> +			printf("Filetype: %s\t", file_type_to_string(cdev->filetype));
> +		if (cdev->dos_partition_type)
> +			printf("DOS parttype: 0x%02x\t", cdev->dos_partition_type);
> +		if (uuid_set)
> +			printf("UUID: %pUl", cdev->uuid);
> +		printf("\n");
> +	}
> +}
> +EXPORT_SYMBOL(cdev_print);
> +
> +static struct fs_device_d *get_fsdevice_by_path(const char *path);
> +
> +void stat_print(const char *filename, const struct stat *st)
> +{
> +	struct block_device *bdev = NULL;
> +	struct fs_device_d *fdev;
> +	struct cdev *cdev = NULL;
> +	const char *type = NULL;
> +	char modestr[11];
> +
> +	mkmodestr(st->st_mode, modestr);
> +
> +	switch (st->st_mode & S_IFMT) {
> +		case S_IFDIR:    type = "directory"; break;
> +		case S_IFBLK:    type = "block special file"; break;
> +		case S_IFCHR:    type = "character special file"; break;
> +		case S_IFIFO:    type = "fifo"; break;
> +		case S_IFLNK:    type = "symbolic link"; break;
> +		case S_IFSOCK:   type = "socket"; break;
> +		case S_IFREG:    type = "regular file"; break;
> +	}
> +
> +	printf("  File: %s\n", filename);
> +
> +	if (st->st_mode & S_IFCHR) {
> +		char *path;
> +
> +		path = canonicalize_path(filename);
> +		if (path) {
> +			const char *devicefile = devpath_to_name(path);
> +
> +			cdev = cdev_by_name(devicefile);
> +			if (cdev)
> +				bdev = cdev_get_block_device(cdev);
> +
> +			free(path);
> +		}
> +	}
> +
> +	printf("  Size: %-20llu", st->st_size);
> +	if (bdev)
> +		printf("Blocks: %llu\tIO Block: %u\t",
> +		       (u64)bdev->num_blocks, 1 << bdev->blockbits);
> +
> +	if (type)
> +		printf("  %s", type);
> +
> +	fdev = get_fsdevice_by_path(filename);
> +
> +	printf("\nDevice: %s\tInode: %lu\tLinks: %u\n",
> +	       fdev ? dev_name(&fdev->dev) : "<unknown>",
> +	       st->st_ino, st->st_nlink);
> +	printf("Access: (%04o/%s)\tUid: (%u)\tGid: (%u)\n",
> +	       st->st_mode & 07777, modestr, st->st_uid, st->st_gid);
> +
> +	if (cdev)
> +		cdev_print(cdev);
> +}
> +EXPORT_SYMBOL(stat_print);
> +
>  static char *cwd;
>  static struct dentry *cwd_dentry;
>  static struct vfsmount *cwd_mnt;
> @@ -91,7 +195,6 @@ postcore_initcall(init_fs);
>  
>  struct filename;
>  
> -static struct fs_device_d *get_fsdevice_by_path(const char *path);
>  static int filename_lookup(struct filename *name, unsigned flags,
>  			   struct path *path);;
>  static struct filename *getname(const char *filename);
> diff --git a/include/fs.h b/include/fs.h
> index b501db38addd..f96839f9ebf4 100644
> --- a/include/fs.h
> +++ b/include/fs.h
> @@ -147,6 +147,9 @@ int ls(const char *path, ulong flags);
>  
>  char *mkmodestr(unsigned long mode, char *str);
>  
> +void stat_print(const char *filename, const struct stat *st);
> +void cdev_print(const struct cdev *cdev);
> +
>  char *canonicalize_path(const char *pathname);
>  
>  char *get_mounted_path(const char *path);
> -- 
> 2.30.2
> 
> 
> 

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