>From a173f8e9296562e5ece3dd2936d799001897d6c6 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Thu, 14 Mar 2013 10:49:23 +0200 Subject: [PATCH] UBIFS: make space fixup work in the remount case The UBIFS space fixup is a useful feature which allows to fixup the "broken" flash space at the time of the first mount. The "broken" space is usually the result of using a "dumb" industrial flasher which is not able to skip empty NAND pages and just writes all 0xFFs to the empty space, which has grave side-effects for UBIFS when UBIFS trise to write useful data to those empty pages. The fix-up feature works roughly like this: 1. mkfs.ubifs sets the fixup flag in UBIFS superblock when creating the image (see -F option) 2. when the file-system is mounted for the first time, UBIFS notices the fixup flag and re-writes the entire media atomically, which may take really a lot of time. 3. UBIFS clears the fixup flag in the superblock. This works fine when the file system is mounted R/W for the very first time. But it did not really work in the case when we first mount the file-system R/O, and then re-mount R/W. The reason was that we started the fixup procedure too late, which we cannot really do because we have to fixup the space before it starts being used. Signed-off-by: Artem Bityutskiy Cc: stable@vger.kernel.org # 3.0+ --- fs/ubifs/super.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index ac838b8..fa4aec6 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -1568,10 +1568,17 @@ static int ubifs_remount_rw(struct ubifs_info *c) c->remounting_rw = 1; c->ro_mount = 0; + if (c->space_fixup) { + err = ubifs_fixup_free_space(c); + if (err) + return err; + } + err = check_free_space(c); if (err) goto out; + if (c->old_leb_cnt != c->leb_cnt) { struct ubifs_sb_node *sup; @@ -1684,12 +1691,6 @@ static int ubifs_remount_rw(struct ubifs_info *c) err = dbg_check_space_info(c); } - if (c->space_fixup) { - err = ubifs_fixup_free_space(c); - if (err) - goto out; - } - mutex_unlock(&c->umount_mutex); return err; -- 1.7.7.6