Commit graph

17 commits

Author SHA1 Message Date
Prasad Joshi
eabb26cacd logfs: fix deadlock in logfs_get_wblocks, hold and wait on super->s_write_mutex
do_logfs_journal_wl_pass() should use GFP_NOFS for memory allocation GC
code calls btree_insert32 with GFP_KERNEL while holding a mutex
super->s_write_mutex.

The same mutex is used in address_space_operations->writepage(), and a
call to writepage() could be triggered as a result of memory allocation
in btree_insert32, causing a deadlock.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20342

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Cc: Joern Engel <joern@logfs.org>
Cc: Florian Mickler <florian@mickler.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-22 19:43:33 -08:00
Al Viro
8e22c1a4e4 logfs: get rid of magical inodes
ordering problems at ->kill_sb() time are solved by doing iput()
of these suckers in ->put_super()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:26 -04:00
Joern Engel
20503664b0 logfs: survive logfs_buf_recover read errors
Refusing to mount beats a kernel crash.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-04 19:37:04 +02:00
Linus Torvalds
255f41c595 Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs
* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
  [LogFS] Split large truncated into smaller chunks
  [LogFS] Set s_bdi
  [LogFS] Prevent mempool_destroy NULL pointer dereference
  [LogFS] Move assertion
  [LogFS] Plug 8 byte information leak
  [LogFS] Prevent memory corruption on large deletes
  [LogFS] Remove unused method

Fix trivial conflict with added header includes in fs/logfs/super.c
2010-04-21 12:31:12 -07:00
Joern Engel
ead88af5f5 [LogFS] Move assertion
The assertion is valid independently of the condition.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-13 17:57:21 +02:00
Joern Engel
d3a03f8031 [LogFS] Plug 8 byte information leak
Within each journal segment, 8 bytes at offset 24 would remain
uninitialized.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-13 17:54:27 +02:00
Joern Engel
032d8f7268 [LogFS] Prevent memory corruption on large deletes
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: Joern Engel <joern@logfs.org>
2010-04-13 17:46:37 +02:00
Tejun Heo
336f5899d2 Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
Tejun Heo
5a0e3ad6af 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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Joern Engel
6be7fa06eb [LogFS] Erase new journal segments
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: Joern Engel <joern@logfs.org>
2010-03-29 21:14:52 +02:00
Joern Engel
0943846ae0 [LogFS] Move reserved segments with journal
Fixes a GC livelock.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-29 21:13:28 +02:00
Joern Engel
723b2ff408 [LogFS] Clear PagePrivate when moving journal
do_logfs_journal_wl_pass() must call freeseg(), thereby clear
PagePrivate on all pages of the current journal segment.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-28 18:10:07 +02:00
Joern Engel
9cf05b416d [LogFS] Remove h_version field
Incompatible change: h_compr is moved up so the padding is all in one chunk.
2010-03-06 10:01:46 +01:00
Joern Engel
c6d3830140 [LogFS] Only write journal if dirty
This prevents unnecessary journal writes.  More importantly it prevents
an oops due to a journal write on failed mount.
2010-03-04 21:36:19 +01:00
Joern Engel
9421502b4f [LogFS] Fix bdev erases
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.
2010-03-04 21:30:58 +01:00
Joern Engel
5c564c2a04 [LogFS] Silence gcc
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?
2009-12-07 12:34:43 +01:00
Joern Engel
5db53f3e80 [LogFS] add new flash file system
This is a new flash file system. See
Documentation/filesystems/logfs.txt

Signed-off-by: Joern Engel <joern@logfs.org>
2009-11-20 20:13:39 +01:00