From e8d6b0e4615ba38b0d3dd6246517b346c91e6a8d Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Date: Tue, 9 Oct 2012 16:20:15 +0300
Subject: [PATCH] UBIFS: fix mounting problems after power cuts
This is a bugfix for a problem with the following symptoms:
1. A power cut happens
2. After reboot, we try to mount UBIFS
3. Mount fails with "No space left on device" error message
UBIFS complains like this:
UBIFS error (pid 28225): grab_empty_leb: could not find an empty LEB
The root cause of this problem is that when we mount, not all LEBs are
categorized. Only those which were read are. However, the
'ubifs_find_free_leb_for_idx()' function assumes that all LEBs were
categorized and 'c->freeable_cnt' is valid, which is a false assumption.
This patch fixes the problem by teaching 'ubifs_find_free_leb_for_idx()'
to always fall back to LPT scanning if no freeable LEBs were found.
This problem was reported by several people in the past, but Brent Taylor
was able to reproduce it and send me a flash image which cannot be mounted,
which made it easy to hunt the bug. Kudos to Brent.
Reported-by: Brent Taylor <motobud@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org
---
fs/ubifs/find.c | 10 ++++------
1 files changed, 4 insertions(+), 6 deletions(-)
@@ -682,12 +682,10 @@ int ubifs_find_free_leb_for_idx(struct ubifs_info *c)
lprops = ubifs_fast_find_freeable(c);
if (!lprops) {
ubifs_assert(c->freeable_cnt == 0);
- if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
- lprops = scan_for_leb_for_idx(c);
- if (IS_ERR(lprops)) {
- err = PTR_ERR(lprops);
- goto out;
- }
+ lprops = scan_for_leb_for_idx(c);
+ if (IS_ERR(lprops)) {
+ err = PTR_ERR(lprops);
+ goto out;
}
}
}
--
1.7.7.6