Although many other filesystems provide a tool for changing volume
label, e.g. e2label for ext filesystem, but f2fs has no way to change
volume label except set it while formatting with mkfs.f2fs.
This introduces f2fslabel, simple tool for changing label of f2fs
volume.
Signed-off-by: Dongwoo Lee <dwoo08....@samsung.com>
---
man/Makefile.am | 2 +-
man/f2fslabel.8 | 33 ++++++++++
tools/Makefile.am | 4 +-
tools/f2fslabel.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 186 insertions(+), 2 deletions(-)
create mode 100644 man/f2fslabel.8
create mode 100644 tools/f2fslabel.c
diff --git a/man/Makefile.am b/man/Makefile.am
index 1d16c6f..9363b82 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -1,3 +1,3 @@
## Makefile.am
-dist_man_MANS = mkfs.f2fs.8 fsck.f2fs.8 dump.f2fs.8 defrag.f2fs.8
resize.f2fs.8 sload.f2fs.8 f2fs_io.8
+dist_man_MANS = mkfs.f2fs.8 fsck.f2fs.8 dump.f2fs.8 defrag.f2fs.8
resize.f2fs.8 sload.f2fs.8 f2fs_io.8 f2fslabel.8
diff --git a/man/f2fslabel.8 b/man/f2fslabel.8
new file mode 100644
index 0000000..848ed3b
--- /dev/null
+++ b/man/f2fslabel.8
@@ -0,0 +1,33 @@
+.\" Copyright (c) 2021 Samsung Electronics Co., Ltd.
+.\"
+.TH F2FSLABEL 8
+.SH NAME
+f2fslabel \- Change the label on an f2fs volume
+.SH SYNOPSIS
+.B f2fslabel
+.I device
+[
+.I volume-label
+]
+.SH DESCRIPTION
+.B f2fslabel
+will display or change the volume label on the f2fs located on
+.I device.
+.PP
+If the optional argument
+.I volume-label
+is present, then
+.B f2fslabel
+will set the volume label to be
+.IR volume-label .
+.PP
+Otherwise,
+.B f2fslabel
+will simply show the current label.
+.PP
+.SH AUTHOR
+.B f2fslabel
+was written by Dongwoo Lee (dwoo08....@samsung.com).
+.SH AVAILABILITY
+.B f2fslabel
+is available from
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git.
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 56bf2e4..84f0ae4 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -2,10 +2,12 @@
AM_CPPFLAGS = ${libuuid_CFLAGS} -I$(top_srcdir)/include
AM_CFLAGS = -Wall
-sbin_PROGRAMS = f2fstat fibmap.f2fs parse.f2fs
+sbin_PROGRAMS = f2fstat fibmap.f2fs parse.f2fs f2fslabel
f2fstat_SOURCES = f2fstat.c
fibmap_f2fs_SOURCES = fibmap.c
parse_f2fs_SOURCES = f2fs_io_parse.c
+f2fslabel_SOURCES = f2fslabel.c
+f2fslabel_LDADD = $(top_builddir)/lib/libf2fs.la
if LINUX
sbin_PROGRAMS += f2fscrypt
diff --git a/tools/f2fslabel.c b/tools/f2fslabel.c
new file mode 100644
index 0000000..3af845c
--- /dev/null
+++ b/tools/f2fslabel.c
@@ -0,0 +1,149 @@
+#include <f2fs_fs.h>
+#include <fcntl.h>
+
+enum SB_ADDR {
+ SB0_ADDR = 0,
+ SB1_ADDR,
+ SB_MAX_ADDR,
+};
+
+#define SB_MASK(i) (1 << (i))
+#define SB_MASK_ALL (SB_MASK(SB0_ADDR) | SB_MASK(SB1_ADDR))
+
+struct f2fs_super_block sb_raw;
+
+static int verify_sb_chksum(struct f2fs_super_block *sb)
+{
+ if (get_sb(checksum_offset) != SB_CHKSUM_OFFSET)
+ return -1;
+
+ if (f2fs_crc_valid(get_sb(crc), sb, get_sb(checksum_offset)))
+ return -1;
+
+ return 0;
+}
+
+static int read_and_check_sb(enum SB_ADDR sb_addr)
+{
+ char buf[F2FS_BLKSIZE];
+ struct f2fs_super_block *sb = &sb_raw;
+
+ if (dev_read_block(buf, sb_addr))
+ return -1;
+
+ memcpy(sb, buf + F2FS_SUPER_OFFSET, sizeof(struct f2fs_super_block));
+
+ if ((get_sb(feature) & F2FS_FEATURE_SB_CHKSUM) &&
+ verify_sb_chksum(sb))
+ return -1;
+
+ if (get_sb(magic) != F2FS_SUPER_MAGIC)
+ return -1;
+
+ return 0;
+}
+
+static int open_sb(int mode)
+{
+ struct device_info *dev = &c.devices[0];
+ int ret;
+
+ ret = open(dev->path, mode);
+ if (ret < 0) {
+ perror(dev->path);
+ fprintf(stderr, "f2fslabel: Failed to open device: %s\n",
+ dev->path);
+ exit(1);
+ }
+
+ dev->fd = ret;
+
+ ret = read_and_check_sb(SB0_ADDR);
+ if (ret) {
+ ret = read_and_check_sb(SB1_ADDR);
+ if (ret) {
+ fprintf(stderr,
+ "f2fslabel: Invalid f2fs superblock: %s\n",
+ dev->path);
+ exit(1);
+ }
+ }
+
+ return 0;
+}
+
+static void print_label(void)
+{
+ struct f2fs_super_block *sb = &sb_raw;
+ char label[MAX_VOLUME_NAME];
+
+ if (open_sb(O_RDONLY))
+ exit(1);
+
+ utf16_to_utf8(label, sb->volume_name, MAX_VOLUME_NAME, MAX_VOLUME_NAME);
+ printf("%s\n", label);
+}
+
+static void update_superblock(struct f2fs_super_block *sb, int sb_mask)
+{
+ int addr, ret;
+ u_int8_t *buf;
+
+ buf = calloc(F2FS_BLKSIZE, 1);
+ ASSERT(buf);
+
+ if (get_sb(feature) & F2FS_FEATURE_SB_CHKSUM) {
+ set_sb(crc, f2fs_cal_crc32(F2FS_SUPER_MAGIC, sb,
+ SB_CHKSUM_OFFSET));
+ }
+
+ memcpy(buf + F2FS_SUPER_OFFSET, sb, sizeof(*sb));
+ for (addr = SB0_ADDR; addr < SB_MAX_ADDR; addr++) {
+ if (SB_MASK(addr) & sb_mask) {
+ ret = dev_write_block(buf, addr);
+ ASSERT(ret >= 0);
+ }
+ }
+
+ free(buf);
+}
+
+static void change_label(char *label)
+{
+ struct f2fs_super_block *sb = &sb_raw;
+ int len;
+
+ if (open_sb(O_RDWR))
+ exit(1);
+
+ len = strlen(label);
+ if (len > MAX_VOLUME_NAME) {
+ fprintf(stderr,
+ "f2fslabel: Label should be less than %d characters\n",
+ MAX_VOLUME_NAME);
+ exit(1);
+ }
+
+ utf8_to_utf16(sb->volume_name, label, MAX_VOLUME_NAME, len);
+
+ update_superblock(sb, SB_MASK_ALL);
+}
+
+int main(int argc, char **argv)
+{
+ if (argc < 2 || argc > 3) {
+ fprintf(stderr, "Usage: f2fslabel device [newlabel]\n");
+ exit(1);
+ }
+
+ f2fs_init_configuration();
+
+ c.devices[0].path = argv[1];
+
+ if (argc == 2)
+ print_label();
+ else if (argc == 3)
+ change_label(argv[2]);
+
+ return 0;
+}
--
2.25.1
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