Commit Graph

185 Commits

Author SHA1 Message Date
Eric Sandeen 37ed322290 [PATCH] JBD: 16T fixes
These are a few places I've found in jbd that look like they may not be
16T-safe, or consistent with the use of unsigned longs for block
containers.  Problems here would be somewhat hard to hit, would require
journal blocks past the 8T boundary, which would not be terribly common.
Still, should fix.

(some of these have come from the ext4 work on jbd as well).

I think there's one more possibility that the wrap() function may not be
safe IF your last block in the journal butts right up against the 232 block
boundary, but that seems like a VERY remote possibility, and I'm not
worrying about it at this point.

Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:09 -07:00
Alexey Dobriyan 2aed348469 [PATCH] jbd: use BUILD_BUG_ON in journal init
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Stephen Tweedie <sct@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:09 -07:00
Mingming Cao ae6ddcc5f2 [PATCH] ext3 and jbd cleanup: remove whitespace
Remove whitespace from ext3 and jbd, before we clone ext4.

Signed-off-by: Mingming Cao<cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:09 -07:00
Josh Triplett e7ab8d6505 [PATCH] jbd: add lock annotation to jbd_sync_bh
jbd_sync_bh releases journal->j_list_lock.  Add a lock annotation to this
function so that sparse can check callers for lock pairing, and so that
sparse will not complain about this function since it intentionally uses
the lock in this manner.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:08 -07:00
Jan Kara 3998b9301d [PATCH] jbd: fix commit of ordered data buffers
Original commit code assumes, that when a buffer on BJ_SyncData list is
locked, it is being written to disk.  But this is not true and hence it can
lead to a potential data loss on crash.  Also the code didn't count with
the fact that journal_dirty_data() can steal buffers from committing
transaction and hence could write buffers that no longer belong to the
committing transaction.  Finally it could possibly happen that we tried
writing out one buffer several times.

The patch below tries to solve these problems by a complete rewrite of the
data commit code.  We go through buffers on t_sync_datalist, lock buffers
needing write out and store them in an array.  Buffers are also immediately
refiled to BJ_Locked list or unfiled (if the write out is completed).  When
the array is full or we have to block on buffer lock, we submit all
accumulated buffers for IO.

[suitable for 2.6.18.x around the 2.6.19-rc2 timeframe]

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Badari Pulavarty 4cfb04a9d3 [PATCH] manage-jbd-its-own-slab fix
Missed a place where I forgot to convert kfree() to kmem_cache_free() as
part of jbd-manage-its-own-slab changes.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-01 11:39:10 -07:00
Badari Pulavarty ea817398e6 [PATCH] Manage jbd allocations from its own slabs
JBD currently allocates commit and frozen buffers from slabs.  With
CONFIG_SLAB_DEBUG, its possible for an allocation to cross the page
boundary causing IO problems.

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=200127

So, instead of allocating these from regular slabs - manage allocation from
its own slabs and disable slab debug for these slabs.

[akpm@osdl.org: cleanups]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:32 -07:00
Randy Dunlap c9cf55285e [PATCH] add poison.h and patch primary users
Localize poison values into one header file for better documentation and
easier/quicker debugging and so that the same values won't be used for
multiple purposes.

Use these constants in core arch., mm, driver, and fs code.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:38 -07:00
Theodore Ts'o e8f1c6227a [PATCH] ext3: fix memory leak when the journal file is corrupted
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:07 -07:00
Jan Kara 78ce89c92b [PATCH] JBD: split checkpoint lists
Split the checkpoint list of the transaction into two lists.  In the first
list we keep the buffers that need to be submitted for IO.  In the second
list are kept buffers that were already submitted and we just have to wait
for the IO to complete.  This should simplify a handling of checkpoint
lists a bit and can eventually be also a performance gain.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:08 -07:00
Andrew Morton 304c4c841a [PATCH] jbd: avoid kfree(NULL)
There are a couple of places where JBD has to check to see whether an unneeded
memory allocation was performed.  Usually it _was_ needed, so we end up
calling kfree(NULL).  We can micro-optimise that by checking the pointer
before calling kfree().

Thanks to Steven Rostedt <rostedt@goodmis.org> for identifying this.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:05 -07:00
Jan Kara 9ada734098 [PATCH] jbd: fix BUG in journal_commit_transaction()
Fix possible assertion failure in journal_commit_transaction() on
jh->b_next_transaction == NULL (when we are processing BJ_Forget list and
buffer is not jbddirty).

!jbddirty buffers can be placed on BJ_Forget list for example by
journal_forget() or by __dispose_buffer() - generally such buffer means
that it has been freed by this transaction.

Freed buffers should not be reallocated until the transaction has committed
(that's why we have the assertion there) but they *can* be reallocated when
the transaction has already been committed to disk and we are just
processing the BJ_Forget list (as soon as we remove b_committed_data from
the bitmap bh, ext3 will be able to reallocate buffers freed by the
committing transaction).  So we have to also count with the case that the
buffer has been reallocated and b_next_transaction has been already set.

And one more subtle point: it can happen that we manage to reallocate the
buffer and also mark it jbddirty.  Then we also add the freed buffer to the
checkpoint list of the committing trasaction.  But that should do no harm.

Non-jbddirty buffers should be filed to BJ_Reserved and not BJ_Metadata
list.  It can actually happen that we refile such buffers during the commit
phase when we reallocate in the running transaction blocks deleted in
committing transaction (and that can happen if the committing transaction
already wrote all the data and is just cleaning up BJ_Forget list).

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: "Stephen C. Tweedie" <sct@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:04 -07:00
NeilBrown 2ff28e22bd [PATCH] Make address_space_operations->invalidatepage return void
The return value of this function is never used, so let's be honest and
declare it as void.

Some places where invalidatepage returned 0, I have inserted comments
suggesting a BUG_ON.

[akpm@osdl.org: JBD BUG fix]
[akpm@osdl.org: rework for git-nfs]
[akpm@osdl.org: don't go BUG in block_invalidate_page()]
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:56:55 -08:00
Andrew Morton 8d8c85117f [PATCH] jbd: convert kjournald to kthread API
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:50 -08:00
Andrew Morton e3df18983e [PATCH] jbd: embed j_commit_timer in journal struct
The kjournald timer is currently on the kernel thread's stack and the journal
structure points at it.  Save a pointer hop by moving the timer into the
journal structure.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:50 -08:00
Arjan van de Ven 2c68ee754c [PATCH] sem2mutex: jbd, j_checkpoint_mutex
Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 07:38:12 -08:00
Mark Fasheh 7c8903f637 [PATCH] jbd: revert checkpoint list changes
This patch reverts commit f93ea411b73594f7d144855fd34278bcf34a9afc:
  [PATCH] jbd: split checkpoint lists

This broke journal_flush() for OCFS2, which is its method of being sure
that metadata is sent to disk for another node.

And two related commits 8d3c7fce2d and
43c3e6f5ab with the subjects:
  [PATCH] jbd: log_do_checkpoint fix
  [PATCH] jbd: remove_transaction fix

These seem to be incremental bugfixes on the original patch and as such are
no longer needed.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14 16:09:34 -08:00
Andrew Morton fe1dcbc4f3 [PATCH] jbd: fix transaction batching
Ben points out that:

  When writing files out using O_SYNC, jbd's 1 jiffy delay results in a
  significant drop in throughput as the disk sits idle.  The patch below
  results in a 4-5x performance improvement (from 6.5MB/s to ~24-30MB/s on my
  IDE test box) when writing out files using O_SYNC.

So optimise the batching code by omitting it entirely if the process which is
doing a sync write is the same as the one which did the most recent sync
write.  If that's true, we're unlikely to get any other processes joining the
transaction.

(Has been in -mm for ages - it took me a long time to get on to performance
testing it)

Numbers, on write-cache-disabled IDE:

/usr/bin/time -p synctest -n 10 -uf -t 1 -p 1 dir-name

Unpatched:
	40 seconds
Patched:
	35 seconds
Batching disabled:
	35 seconds

This is the problematic single-process-doing-fsync case.  With multiple
fsyncing processes the numbers are AFACIT unaltered by the patch.

Aside: performance testing and instrumentation shows that the transaction
batching almost doesn't help (testing with synctest -n 1 -uf -t 100 -p 10
dir-name on non-writeback-caching IDE).  This is because by the time one
process is running a synchronous commit, a bunch of other processes already
have a transaction handle open, so they're all going to batch into the same
transaction anyway.

The batching seems to offer maybe 5-10% speedup with this workload, but I'm
pretty sure it was more important than that when it was first developed 4-odd
years ago...

Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:06:53 -08:00
Jan Kara 43c3e6f5ab [PATCH] jbd: remove_transaction fix
We have to check that also the second checkpoint list is non-empty before
dropping the transaction.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:16 -08:00
Jan Kara 8d3c7fce2d [PATCH] jbd: log_do_checkpoint fix
While checkpointing we have to check that our transaction still is in the
checkpoint list *and* (not or) that it's not just a different transaction
with the same address.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:16 -08:00
Jan Kara f93ea411b7 [PATCH] jbd: split checkpoint lists
Split the checkpoint list of the transaction into two lists.  In the first
list we keep the buffers that need to be submitted for IO.  In the second
list are kept buffers that were already submitted and we just have to wait
for the IO to complete.  This should simplify a handling of checkpoint
lists a bit and can eventually be also a performance gain.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:59 -08:00
Jesper Juhl f99d49adf5 [PATCH] kfree cleanup: fs
This is the fs/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in fs/.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:54:06 -08:00
Randy Dunlap 6c8bec6d5f [PATCH] jbd doc: fix some kernel-doc warnings
Add structure fields kernel-doc for 2 fields in struct journal_s.

Warning(/var/linsrc/linux-2614-rc4//include/linux/jbd.h:808): No description found for parameter 'j_wbuf'
Warning(/var/linsrc/linux-2614-rc4//include/linux/jbd.h:808): No description found for parameter 'j_wbufsize'

Convert fs/jbd/recovery.c non-static functions to kernel-doc format.

fs/jbd/recovery.c doesn't export any symbols, so it should use
!I instead of !E to eliminate this warning message:

Warning(/var/linsrc/linux-2614-rc4//fs/jbd/recovery.c): no structured comments found

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:55 -08:00
Al Viro 27496a8c67 [PATCH] gfp_t: fs/*
- ->releasepage() annotated (s/int/gfp_t), instances updated
 - missing gfp_t in fs/* added
 - fixed misannotation from the original sweep caught by bitwise checks:
   XFS used __nocast both for gfp_t and for flags used by XFS allocator.
   The latter left with unsigned int __nocast; we might want to add a
   different type for those but for now let's leave them alone.  That,
   BTW, is a case when __nocast use had been actively confusing - it had
   been used in the same code for two different and similar types, with
   no way to catch misuses.  Switch of gfp_t to bitwise had caught that
   immediately...

One tricky bit is left alone to be dealt with later - mapping->flags is
a mix of gfp_t and error indications.  Left alone for now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28 08:16:47 -07:00
Nishanth Aravamudan 041e0e3b19 [PATCH] fs: fix-up schedule_timeout() usage
Use schedule_timeout_{,un}interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.  Also use helper
functions to convert between human time units and jiffies rather than constant
HZ division to avoid rounding errors.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 10:06:36 -07:00
Jan Kara 4407c2b6b2 [PATCH] Fix race in do_get_write_access()
attached patch should fix the following race:
     Proc 1                               Proc 2

     __flush_batch()
       ll_rw_block()
                                        do_get_write_access()
					   lock_buffer
                                             jh is only waiting for checkpoint
					     -> b_transaction == NULL ->
					     do nothing
                                           unlock_buffer
    test_set_buffer_locked()
    test_clear_buffer_dirty()
                                           __journal_file_buffer()
                                        change the data
    submit_bh()

and we have sent wrong data to disk...  We now clean the dirty buffer flag
under buffer lock in all cases and hence we know that whenever a buffer is
starting to be journaled we either finish the pending write-out before
attaching a buffer to a transaction or we won't write the buffer until the
transaction is going to be committed.

The test in jbd_unexpected_dirty_buffer() is redundant - remove it.
Furthermore we have to clear the buffer dirty bit under the buffer lock to
prevent races with buffer write-out (and hence prevent returning a buffer with
IO happening).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:57 -07:00
Jan Kara 26707699b5 [PATCH] Change ll_rw_block() calls in JBD
We must be sure that the current data in buffer are sent to disk.  Hence we
have to call ll_rw_block() with SWRITE.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:55 -07:00
Jan Kara e6c9f5c188 [PATCH] Fix JBD race in t_forget list handling
Fix race between journal_commit_transaction() and other places as
journal_unmap_buffer() that are adding buffers to transaction's t_forget list.
 We have to protect against such places by holding j_list_lock even when
traversing the t_forget list.  The fact that other places can only add buffers
to the list makes the locking easier.  OTOH the lock ranking complicates the
stuff...

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:54 -07:00
Mark Fasheh cbf0d27a13 [PATCH] kjournald: missing JFS_UNMOUNT check
It seems that kjournald() may be missing a check of the JFS_UNMOUNT flag
before calling schedule().  This showed up in testing of OCFS2 recovery
where our recovery thread would hang in journal_kill_thread() called from
journal_destroy() because kjournald never got a chance to read the flag to
shut down before the schedule().

Zach pointed out the missing check which led me to hack up this trivial
patch.  It's been tested many times now and I have yet to reproduce the
hang, which was happening very regularly before.

<mild rant>
I'm guessing that we could really use some wait_event() calls with helper
functions in, well, most of jbd these days which would make a ton of the
wait code there vastly cleaner.
</mild rant>

As for why this doesn't happen in ext3 (or OCFS2 during normal
mount/unmount of the local nodes journal), I think it may that the specific
timing of events in the ocfs2 recovery thread exposes a race there.
Because ocfs2_replay_journal() is only interested in playing back the
journal, initialization and shutdown happen very quicky with no other
metadata put into that specific journal.

Acked-by: "Stephen C. Tweedie" <sct@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:54 -07:00
Adrian Bunk 022a4a7bbd [PATCH] fs/jbd/: cleanups
This patch contains the following cleanups:
- make needlessly global functions static
- journal.c: remove the unused global function __journal_internal_check
             and move the check to journal_init
- remove the following write-only global variable:
  - journal.c: current_journal
- remove the following unneeded EXPORT_SYMBOL:
  - journal.c: journal_recover

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:19 -07:00
Christoph Lameter 3e1d1d28d9 [PATCH] Cleanup patch for process freezing
1. Establish a simple API for process freezing defined in linux/include/sched.h:

   frozen(process)		Check for frozen process
   freezing(process)		Check if a process is being frozen
   freeze(process)		Tell a process to freeze (go to refrigerator)
   thaw_process(process)	Restart process
   frozen_process(process)	Process is frozen now

2. Remove all references to PF_FREEZE and PF_FROZEN from all
   kernel sources except sched.h

3. Fix numerous locations where try_to_freeze is manually done by a driver

4. Remove the argument that is no longer necessary from two function calls.

5. Some whitespace cleanup

6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
   cleared before setting PF_FROZEN, recalc_sigpending does not check
   PF_FROZEN).

This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!

Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 17:10:13 -07:00
Jan Kara 7e3b11a9be [PATCH] ext3: fix list scanning in __cleanup_transaction
Fix a bug in list scanning that can cause us to skip the last buffer on the
checkpoint list (and hence fail to do any progress under some rather
unfavorable conditions).

The problem is we first do jh=next_jh and then test

	} while (jh!=last_jh);

Hence we skip the last buffer on the list (if it was not the only buffer on
the list).  As we already do jh=next_jh; in the beginning of the loop we
are safe to just remove the assignment in the end.  It can happen that 'jh'
will be freed at the point we test jh != last_jh but that does not matter
as we never *dereference* the pointer.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-02 15:12:29 -07:00
Jan Kara 00ea81459c [PATCH] ext3: fix log_do_checkpoint() assertion failure
Fix possible false assertion failure in log_do_checkpoint().  We might fail
to detect that we actually made a progress when cleaning up the checkpoint
lists if we don't retry after writing something to disk.  The patch was
confirmed to fix observed assertion failures for several users.

When we flushed some buffers we need to retry scanning the list.
Otherwise we can fail to detect our progress.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-02 15:12:29 -07:00
akpm@osdl.org d13df84ff7 [PATCH] jbd dirty buffer leak fix
This fixes the lots-of-fsx-linux-instances-cause-a-slow-leak bug.

It's been there since 2.6.6, caused by:

ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.5/2.6.5-mm4/broken-out/jbd-move-locked-buffers.patch

That patch moves under-writeout ordered-data buffers onto a separate journal
list during commit.  It took out the old code which was based on a single
list.

The old code (necessarily) had logic which would restart I/O against buffers
which had been redirtied while they were on the committing transaction's
t_sync_datalist list.  The new code only writes buffers once, ignoring
redirtyings by a later transaction, which is good.

But over on the truncate side of things, in journal_unmap_buffer(), we're
treating buffers on the t_locked_list as inviolable things which belong to the
committing transaction, and we just leave them alone during concurrent
truncate-vs-commit.

The net effect is that when truncate tries to invalidate a page whose buffers
are on t_locked_list and have been redirtied, journal_unmap_buffer() just
leaves those buffers alone.  truncate will remove the page from its mapping
and we end up with an anonymous clean page with dirty buffers, which is an
illegal state for a page.  The JBD commit will not clean those buffers as they
are removed from t_locked_list.  The VM (try_to_free_buffers) cannot reclaim
these pages.

The patch teaches journal_unmap_buffer() about buffers which are on the
committing transaction's t_locked_list.  These buffers have been written and
I/O has completed.  We can take them off the transaction and undirty them
within the context of journal_invalidatepage()->journal_unmap_buffer().

Acked-by: "Stephen C. Tweedie" <sct@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16 15:26:36 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00