This is the second fix of the following symptom:

UBIFS error (pid 34456): could not find an empty LEB

which sometimes happens after power cuts when we mount the file-system - UBIFS
refuses it with the above error message which comes from the
'ubifs_rcvry_gc_commit()' function. I can reproduce this using the integck test
with the UBIFS power cut emulation enabled.

Analysis of the problem.

Currently UBIFS replay seeks the journal heads to the last _replayed_ bud.
But the buds are replayed out-of-order, so the replay basically seeks journal
heads to the "random" bud belonging to this head, and not to the _last_ one.

The result of this is that the GC head may be seeked to a full LEB with no free
space, or very little free space. And 'ubifs_rcvry_gc_commit()' tries to find a
fully or mostly dirty LEB to match the current GC head (because we need to
garbage-collect that dirty LEB at one go, because we do not have @c->gc_lnum).
So 'ubifs_find_dirty_leb()' fails and we fall back to finding an empty LEB and
also fail. As a result - recovery fails and mounting fails.

This patch teaches the replay to initialize the GC heads exactly to the latest
buds, i.e. the buds which have the largest sequence number in corresponding
log reference nodes.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org

In 'ubifs_replay_journal()' we allocate 'sbuf' for scanning the log.
However, we already have 'c->sbuf' for these purposes, so do not
allocate yet another one. This reduces UBIFS memory consumption while
recovering.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Add a commentary which elaborates that 'ubifs_recover_log_leb()' recovers only
the last log LEB, not any. Also remove some unneeded newlines.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Commit 2fde99cb "UBIFS: mark VFS SB RO too"
introduced regression. This commit made UBIFS set the 'MS_RDONLY' flag in the
VFS superblock when it switches to R/O mode due to an error. This was done
to make VFS show the R/O UBIFS flag in /proc/mounts.

However, several places in UBIFS relied on the 'MS_RDONLY' flag and assume this
flag can only change when we re-mount. For example, 'ubifs_put_super()'.

This patch introduces new UBIFS flag - 'c->ro_mount' which changes only when
we re-mount, and preserves the way UBIFS was originally mounted (R/W or R/O).
This allows us to de-initialize UBIFS cleanly in 'ubifs_put_super()'.

This patch also changes all 'ubifs_assert(!c->ro_media)' assertions to
'ubifs_assert(!c->ro_media && !c->ro_mount)', because we never should write
anything if the FS was mounter R/O.

All the places where we test for 'MS_RDONLY' flag in the VFS SB were changed
and now we test the 'c->ro_mount' flag instead, because it preserves the
original UBIFS mount type, unlike the 'MS_RDONLY' flag.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

At the moment UBIFS print large and scary error messages and
flash dumps in case of nearly any corruption, even if it is
a recoverable corruption. For example, if the master node is
corrupted, ubifs_scan() prints error dumps, then UBIFS recovers
just fine and goes on.

This patch makes UBIFS print scary error messages only in
real cases, which are not recoverable. It adds 'quiet' argument
to the 'ubifs_scan()' function, so the caller may ask 'ubi_scan()'
not to print error messages if the caller is able to do recovery.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: NAdrian Hunter <Adrian.Hunter@nokia.com>

This patch fixes few minor things I've spotted while going through
code:

1. Better document return codes
2. If 'ubifs_scan_a_node()' returns some thing we do not expect,
   treat this as an error.
3. Try to do recovery only when 'ubifs_scan()' returns %-EUCLEAN,
   not on any error.
4. If empty space starts at a non-aligned address, print a message.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: NAdrian Hunter <Adrian.Hunter@nokia.com>

Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>

Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBIFS stores uncommitted index size in c->budg_uncommitted_idx,
and this affect budgeting calculations. When mounting and
replaying, this variable is not updated, so we may end up
with "over-budgeting". This patch fixes the issue.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We print 'ino_t' type using '%lu' printk() placeholder, but this
results in many warnings when compiling for Alpha platform. Fix
this by adding (unsingned long) casts.

Fixes these warnings:

fs/ubifs/journal.c:693: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/journal.c:1131: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/dir.c:163: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/tnc.c:2680: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/tnc.c:2700: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/replay.c:1066: warning: format '%lu' expects type 'long unsigned int', but argument 7 has type 'ino_t'
fs/ubifs/orphan.c:108: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:135: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:142: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:154: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:159: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:451: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:539: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:612: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:843: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:856: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1438: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1443: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1475: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1495: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:105: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:105: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:110: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:110: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:114: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:114: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:118: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:118: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:1591: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1671: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1674: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1680: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1699: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1788: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1821: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1833: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1924: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1932: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1938: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1945: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1953: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1960: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1967: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1973: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1988: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1991: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:2009: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'ino_t'
Reported-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.htmlSigned-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>