diff options
author | Azat Khuzhin <a3at.mail@gmail.com> | 2014-07-28 11:43:24 +0400 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2014-07-28 20:21:59 -0400 |
commit | 7dfefaf413bbd4f7f51e2664dc4911873236ffdd (patch) | |
tree | f89d50da6c1745f6f9051abe0ad5876e72db213c /misc | |
parent | 3e077c357cf20417547c8a4e589489c2ebdd66ca (diff) | |
download | e2fsprogs-7dfefaf413bbd4f7f51e2664dc4911873236ffdd.tar.gz |
tune2fs: update journal super block when changing UUID for fs.
Using -U option you can change the UUID for fs, however it will not work
for journal device, since it have a copy of this UUID inside jsb (i.e.
journal super block). So copy UUID on change into that block.
Here is the initial thread:
http://comments.gmane.org/gmane.comp.file-systems.ext4/44532
You can reproduce this by executing following commands:
$ fallocate -l100M /tmp/dev
$ fallocate -l100M /tmp/journal
$ sudo /sbin/losetup /dev/loop1 /tmp/dev
$ sudo /sbin/losetup /dev/loop0 /tmp/journal
$ mke2fs -O journal_dev /tmp/journal
$ tune2fs -U da1f2ed0-60f6-aaaa-92fd-738701418523 /tmp/journal
$ sudo mke2fs -t ext4 -J device=/dev/loop0 /dev/loop1
$ dumpe2fs -h /tmp/dev | fgrep UUID
dumpe2fs 1.43-WIP (18-May-2014)
Filesystem UUID: 8a776be9-12eb-411f-8e88-b873575ecfb6
Journal UUID: e3d02151-e776-4865-af25-aecb7291e8e5
$ sudo e2fsck /dev/vdc
e2fsck 1.43-WIP (18-May-2014)
External journal does not support this filesystem
/dev/loop1: ********** WARNING: Filesystem still has errors **********
Reported-by: Chin Tzung Cheng <chintzung@gmail.com>
Signed-off-by: Azat Khuzhin <a3at.mail@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'misc')
-rw-r--r-- | misc/tune2fs.c | 74 |
1 files changed, 56 insertions, 18 deletions
diff --git a/misc/tune2fs.c b/misc/tune2fs.c index 1df655a2..74e57ae6 100644 --- a/misc/tune2fs.c +++ b/misc/tune2fs.c @@ -175,6 +175,38 @@ static __u32 clear_ok_features[3] = { EXT4_FEATURE_RO_COMPAT_GDT_CSUM }; +/** + * Try to get journal super block if any + */ +static int get_journal_sb(ext2_filsys jfs, char buf[SUPERBLOCK_SIZE]) +{ + int retval; + int start; + journal_superblock_t *jsb; + + if (!(jfs->super->s_feature_incompat & + EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) { + return EXT2_ET_UNSUPP_FEATURE; + } + + /* Get the journal superblock */ + if ((retval = io_channel_read_blk64(jfs->io, + ext2fs_journal_sb_start(jfs->blocksize), -SUPERBLOCK_SIZE, buf))) { + com_err(program_name, retval, "%s", + _("while reading journal superblock")); + return retval; + } + + jsb = (journal_superblock_t *) buf; + if ((jsb->s_header.h_magic != (unsigned)ntohl(JFS_MAGIC_NUMBER)) || + (jsb->s_header.h_blocktype != (unsigned)ntohl(JFS_SUPERBLOCK_V2))) { + fputs(_("Journal superblock not found!\n"), stderr); + return EXT2_ET_BAD_MAGIC; + } + + return 0; +} + /* * Remove an external journal from the filesystem */ @@ -218,29 +250,15 @@ static int remove_journal_device(ext2_filsys fs) _("while trying to open external journal")); goto no_valid_journal; } - if (!(jfs->super->s_feature_incompat & - EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) { - fprintf(stderr, _("%s is not a journal device.\n"), - journal_path); - goto no_valid_journal; - } - start = ext2fs_journal_sb_start(fs->blocksize); - /* Get the journal superblock */ - if ((retval = io_channel_read_blk64(jfs->io, start, - -SUPERBLOCK_SIZE, buf))) { - com_err(program_name, retval, "%s", - _("while reading journal superblock")); + if ((retval = get_journal_sb(jfs, buf))) { + if (retval == EXT2_ET_UNSUPP_FEATURE) + fprintf(stderr, _("%s is not a journal device.\n"), + journal_path); goto no_valid_journal; } jsb = (journal_superblock_t *) buf; - if ((jsb->s_header.h_magic != (unsigned)ntohl(JFS_MAGIC_NUMBER)) || - (jsb->s_header.h_blocktype != (unsigned)ntohl(JFS_SUPERBLOCK_V2))) { - fputs(_("Journal superblock not found!\n"), stderr); - goto no_valid_journal; - } - /* Find the filesystem UUID */ nr_users = ntohl(jsb->s_nr_users); for (i = 0; i < nr_users; i++) { @@ -2184,6 +2202,7 @@ retry_open: if (U_flag) { int set_csum = 0; dgrp_t i; + char buf[SUPERBLOCK_SIZE]; if (sb->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) { @@ -2229,6 +2248,25 @@ retry_open: ext2fs_group_desc_csum_set(fs, i); fs->flags &= ~EXT2_FLAG_SUPER_ONLY; } + + /* If this is a journal dev, we need to copy UUID into jsb */ + if (!(rc = get_journal_sb(fs, buf))) { + journal_superblock_t *jsb; + + jsb = (journal_superblock_t *) buf; + fputs(_("Need to update journal superblock.\n"), stdout); + memcpy(jsb->s_uuid, sb->s_uuid, sizeof(sb->s_uuid)); + + /* Writeback the journal superblock */ + if ((rc = io_channel_write_blk64(fs->io, + ext2fs_journal_sb_start(fs->blocksize), + -SUPERBLOCK_SIZE, buf))) + goto closefs; + } else if (rc != EXT2_ET_UNSUPP_FEATURE) + goto closefs; + else + rc = 0; /** Reset rc to avoid ext2fs_mmp_stop() */ + ext2fs_mark_super_dirty(fs); } if (I_flag) { |