Ensures we only return -ENOSPC when there really is no space.
Signed-off-by: NJoern Engel <joern@logfs.org>

Refusing to mount beats a kernel crash.
Signed-off-by: NJoern Engel <joern@logfs.org>

logfs_seek_hole() may return the same offset it is passed as argument.
Found by Prasad Joshi <prasadjoshi124@gmail.com>
Signed-off-by: NJoern Engel <joern@logfs.org>

logfs_seek_hole(inode, 0x200) would crap itself if the inode contained
just 0x1ff (or fewer) blocks.
Signed-off-by: NJoern Engel <joern@logfs.org>

Signed-off-by: NJoern Engel <joern@logfs.org>

Signed-off-by: NJoern Engel <joern@logfs.org>

There is a typo here.  We should test "last" instead of "first".
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJoern Engel <joern@logfs.org>

Truncate would do an almost limitless amount of work without invoking
the garbage collector in between.  Split it up into more manageable,
though still large, chunks.
Signed-off-by: NJoern Engel <joern@logfs.org>

Since 32a88aa1 sync() was turned into a NOP for logfs.  Worse, sync()
would not return an error, giving the illusion that writeout had
actually happened.

Afaics jffs2 was broken as well.
Signed-off-by: NJoern Engel <joern@logfs.org>

It would probably be better to just accept NULL pointers in
mempool_destroy().  But for the current -rc series let's keep things
simple.

This patch was lost in the cracks for a while.
Kevin Cernekee <cernekee@gmail.com> had to rediscover the problem and
send a similar patch because of it. :(
Signed-off-by: NJoern Engel <joern@logfs.org>

The assertion is valid independently of the condition.
Signed-off-by: NJoern Engel <joern@logfs.org>

Within each journal segment, 8 bytes at offset 24 would remain
uninitialized.
Signed-off-by: NJoern Engel <joern@logfs.org>

Removing sufficiently large files would create aliases for a large
number of segments.  This in turn results in a large number of journal
entries and an overflow of s_je_array.

Cheap fix is to add a BUG_ON, turning memory corruption into something
annoying, but less dangerous.  Real fix is to count the number of
affected segments and prevent the problem completely.
Signed-off-by: NJoern Engel <joern@logfs.org>

All callers are long gone.
Signed-off-by: NJoern Engel <joern@logfs.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

If the device contains on old logfs image and the journal is moved to
segment that have never been used by the current logfs and not all
journal segments are erased before the next mount, the old content can
confuse mount code.  To prevent this, always erase the new journal
segments.
Signed-off-by: NJoern Engel <joern@logfs.org>

Fixes a GC livelock.
Signed-off-by: NJoern Engel <joern@logfs.org>

do_logfs_journal_wl_pass() must call freeseg(), thereby clear
PagePrivate on all pages of the current journal segment.
Signed-off-by: NJoern Engel <joern@logfs.org>

A comment in the old code read:
        /* The math in this function can surely use some love */

And indeed it did.  In the case that area->a_used_bytes is exactly
4096 bytes below segment size it fell apart.  pad_wbuf is now split
into two helpers that are significantly less complicated.
Signed-off-by: NJoern Engel <joern@logfs.org>

The comment was correct, so make the code match the comment.  As the
new comment indicates, we might be able to do a little less work.  But
for the current -rc series let's keep it simple and just fix the bug.
Signed-off-by: NJoern Engel <joern@logfs.org>

Found by Al Viro.
Signed-off-by: NJoern Engel <joern@logfs.org>

rootdir was already allocated, so we must iput it again.
Found by Al Viro.
Signed-off-by: NJoern Engel <joern@logfs.org>

If the first superblock is wrong and the second gets written, there
will still be a mismatch on next mount.  Write both to make sure they
match.
Signed-off-by: NJoern Engel <joern@logfs.org>

Apparently filldir can sleep, which forbids kmap_atomic.
Signed-off-by: NJoern Engel <joern@logfs.org>

Signed-off-by: NJoern Engel <joern@logfs.org>

Intel SSDs have a limit of 0xffff as queue_max_hw_sectors(q).  Such a
limit may make sense from a hardware pov, but it causes bio_alloc() to
return NULL.
Signed-off-by: NJoern Engel <joern@logfs.org>

logfs_recover_sb() needs it open.
Signed-off-by: NJoern Engel <joern@logfs.org>

Many changes were made during development that could result in old
versions of mklogfs and the kernel code being subtly incompatible.
Not being a friend of subtleties, I hereby change the magic number.
Any old version of mklogfs is now guaranteed to fail.

Incompatible change: h_compr is moved up so the padding is all in one chunk.

This prevents unnecessary journal writes.  More importantly it prevents
an oops due to a journal write on failed mount.

Erases for block devices were always just emulated by writing 0xff.
Some time back the write was removed and only the page cache was
changed to 0xff.  Superficialy a good idea with two problems:
1. Touching the page cache isn't necessary either.
2. However, writing out 0xff _is_ necessary for the journal.  As the
   journal is scanned linearly, an old non-overwritten commit entry
   can be used on next mount and cause havoc.

This should fix both aspects.

Andrew Morton sayeth:
fs/logfs/journal.c: In function 'logfs_init_journal':
fs/logfs/journal.c:266: warning: 'last_len' may be used uninitialized in this function

Can this be squished please?

Randy Dunlap caught this built error on i386:

fs/built-in.o: In function `hash_index':
dir.c:(.text+0x6c1f2): undefined reference to `__umoddi3'

Spotted by Dan Carpenter.

This is a new flash file system. See
Documentation/filesystems/logfs.txt
Signed-off-by: NJoern Engel <joern@logfs.org>