| From | Luis Henriques <> | Subject | [PATCH 100/102] UBIFS: make space fixup work in the remount case | Date | Mon, 8 Apr 2013 10:50:55 +0100 |
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3.5.7.10 -stable review patch. If anyone has any objections, please let me know.
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From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
commit 67e753ca41782913d805ff4a8a2b0f60b26b7915 upstream.
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 <artem.bityutskiy@linux.intel.com> Reported-by: Mark Jackson <mpfj-list@mimc.co.uk> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/ubifs/super.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 5862dd9..202c0e4 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -1579,6 +1579,12 @@ 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; @@ -1695,12 +1701,6 @@ 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; -- 1.8.1.2
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