the names were too generic:
drivers/uio/uio.c:87: error: expected identifier or '(' before 'do'
drivers/uio/uio.c:87: error: expected identifier or '(' before 'while'
drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).
This also facilitates lockdeping of page lock.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ordered mode, the current jbd2 aborts the journal if a file data buffer
has an error. But this behavior is unintended, and we found that it has
been adopted accidentally.
This patch undoes it and just calls printk() instead of aborting the
journal. Unlike a similar patch for ext3/jbd, file data buffers are
written via generic_writepages(). But we also need to set AS_EIO
into their mappings because wait_on_page_writeback_range() clears
AS_EIO before a user process sees it.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This provides a new ordered mode implementation which gets rid of using
buffer heads to enforce the ordering between metadata change with the
related data chage. Instead, in the new ordering mode, it keeps track
of all of the inodes touched by each transaction on a list, and when
that transaction is committed, it flushes all of the dirty pages for
those inodes. In addition, the new ordered mode reverses the lock
ordering of the page lock and transaction lock, which provides easier
support for delayed allocation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch adds necessary framework into JBD2 to be able to track inodes
with each transaction and write-out their dirty data during transaction
commit time.
This new ordered mode brings all sorts of advantages such as possibility
to get rid of journal heads and buffer heads for data buffers in ordered
mode, better ordering of writes on transaction commit, simplification of
some JBD code, no more anonymous pages when truncate of data being
committed happens. Also with this new ordered mode, delayed allocation
on ordered mode is much simpler.
Signed-off-by: Jan Kara <jack@suse.cz>
journal_try_to_free_buffers() could race with jbd commit transaction
when the later is holding the buffer reference while waiting for the
data buffer to flush to disk. If the caller of
journal_try_to_free_buffers() request tries hard to release the buffers,
it will treat the failure as error and return back to the caller. We
have seen the directo IO failed due to this race. Some of the caller of
releasepage() also expecting the buffer to be dropped when passed with
GFP_KERNEL mask to the releasepage()->journal_try_to_free_buffers().
With this patch, if the caller is passing the GFP_KERNEL to indicating
this call could wait, in case of try_to_free_buffers() failed, let's
waiting for journal_commit_transaction() to finish commit the current
committing transaction , then try to free those buffers again with
journal locked.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Carlo Wood has demonstrated that it's possible to recover deleted
files from the journal. Something that will make this easier is if we
can put the time of the commit into commit block.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If the device doesn't support write barriers, the write is retried
without ordered mode. But the buffer head needs to be re-locked or
submit_bh will fail with on BUG(!buffer_locked(bh)).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If a journal checksum error is detected, the ext4 filesystem will call
ext4_error(), and the mount will either continue, become a read-only
mount, or cause a kernel panic based on the superblock flags
indicating the user's preference of what to do in case of filesystem
corruption being detected.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Updating the current transaction's t_state is protected by j_state_lock. We
need to do the same when updating the t_state to T_COMMIT.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
bdevname() fills the buffer that it is given as a parameter, so calling
strcpy() or snprintf() on the returned value is redundant (and probably not
guaranteed to work - I don't think strcpy and snprintf support overlapping
buffers.)
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
jbd2 debugfs and stats entries should only be created if cache initialisation
is successful. At the moment they are being created unconditionally which
will leave them dangling if cache (and hence module) initialisation fails.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If an error occurs during jbd2 cache initialisation it is possible for the
journal_head_cache to be NULL when jbd2_journal_destroy_journal_head_cache is
called. Replace the J_ASSERT with an if block to handle the situation
correctly.
Note that even with this fix things will break badly if jbd2 is statically
compiled in and cache initialisation fails.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The revocation table initialisation/destruction code is repeated for each of
the two revocation tables stored in the journal. Refactoring the duplicated
code into functions is tidier, simplifies the logic in initialisation in
particular, and slightly reduces the code size.
There should not be any functional change.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Make revocation cache destruction safe to call if initialisation fails
partially or entirely. This allows it to be used to cleanup in the case of
initialisation failure, simplifying the code slightly.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
There are several cases where the running transaction can get buffers
added to its BJ_Metadata list which it never dirtied, which makes its
t_nr_buffers counter end up larger than its t_outstanding_credits
counter.
This will cause issues when starting new transactions as while we are
logging buffers we decrement t_outstanding_buffers, so when
t_outstanding_buffers goes negative, we will report that we need less
space in the journal than we actually need, so transactions will be
started even though there may not be enough room for them. In the worst
case scenario (which admittedly is almost impossible to reproduce) this
will result in the journal running out of space.
The fix is to only refile buffers from the committing transaction to the
running transactions BJ_Modified list when b_modified is set on that
journal, which is the only way to be sure if the running transaction has
modified that buffer.
This patch also fixes an accounting error in journal_forget, it is
possible that we can call journal_forget on a buffer without having
modified it, only gotten write access to it, so instead of freeing a
credit, we only do so if the buffer was modified. The assert will help
catch if this problem occurs. Without these two patches I could hit
this assert within minutes of running postmark, with them this issue no
longer arises.
Cc: <linux-ext4@vger.kernel.org>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently at the start of a journal commit we loop through all of the buffers
on the committing transaction and clear the b_modified flag (the flag that is
set when a transaction modifies the buffer) under the j_list_lock.
The problem is that everywhere else this flag is modified only under the jbd2
lock buffer flag, so it will race with a running transaction who could
potentially set it, and have it unset by the committing transaction.
This is also a big waste, you can have several thousands of buffers that you
are clearing the modified flag on when you may not need to. This patch
removes this code and instead clears the b_modified flag upon entering
do_get_write_access/journal_get_create_access, so if that transaction does
indeed use the buffer then it will be accounted for properly, and if it does
not then we know we didn't use it.
That will be important for the next patch in this series. Tested thoroughly
by myself using postmark/iozone/bonnie++.
Cc: <linux-ext4@vger.kernel.org>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a long-standing typo (predating git) that will cause data corruption if a
journal data block needs unescaping. At the moment the wrong buffer head's
data is being unescaped.
To test this case mount a filesystem with data=journal, start creating and
deleting a bunch of files containing only JBD2_MAGIC_NUMBER (0xc03b3998), then
pull the plug on the device. Without this patch the files will contain zeros
instead of the correct data after recovery.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In JBD2 jbd2_journal_write_commit_record(), clear the buffer_ordered
flag for the bh after barried IO has succeed. This prevents later, if
the same buffer head were submitted to the underlying device, which has
been reconfigured to not support barrier request, the JBD2 commit code
could treat it as a normal IO (without barrier).
This is a port from JBD/ext3 fix from Neil Brown.
More details from Neil:
Some devices - notably dm and md - can change their behaviour in
response to BIO_RW_BARRIER requests. They might start out accepting
such requests but on reconfiguration, they find out that they cannot
any more. JBD2 deal with this by always testing if BIO_RW_BARRIER
requests fail with EOPNOTSUPP, and retrying the write
requests without the barrier (probably after waiting for any pending
writes to complete).
However there is a bug in the handling this in JBD2 for ext4 .
When ext4/JBD2 to submit a BIO_RW_BARRIER request,
it sets the buffer_ordered flag on the buffer head.
If the request completes successfully, the flag STAYS SET.
Other code might then write the same buffer_head after the device has
been reconfigured to not accept barriers. This write will then fail,
but the "other code" is not ready to handle EOPNOTSUPP errors and the
error will be treated as fatal.
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT needs to be checked with
JBD2_HAS_INCOMPAT_FEATURE
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With journal checksum patch we added asynchronous commits of journal
commit headers, and accidentally dropped taking a reference on the
buffer head.
(Before the change, sync_dirty_buffer did the get_bh(). The associative
put_bh is done by journal_wait_on_commit_record().)
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The buffer head pointer passed to journal_wait_on_commit_record() could
be NULL if the previous journal_submit_commit_record() failed or journal
has already aborted.
Looking at the jbd2 debug messages, before the oops happened, the jbd2
is aborted due to trying to access the next log block beyond the end
of device. This might be caused by using a corrupted image.
We need to check the error returns from journal_submit_commit_record()
and avoid calling journal_wait_on_commit_record() in the failure case.
This addresses Kernel Bugzilla #9849
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
None of the callers of this function does actually take the BKL as far as I
can see. So remove the comment refering to the BKL.
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: <linux-ext4@vger.kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The break_lock data structure and code for spinlocks is quite nasty.
Not only does it double the size of a spinlock but it changes locking to
a potentially less optimal trylock.
Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a
__raw_spin_is_contended that uses the lock data itself to determine whether
there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is
not set.
Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to
decouple it from the spinlock implementation, and make it typesafe (rwlocks
do not have any need_lockbreak sites -- why do they even get bloated up
with that break_lock then?).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Get rid of sparse related warnings from places that use integer as NULL
pointer. (Ported from upstream ext3/jbd changes.)
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
While "every 5 seconds" doesn't sound as a problem, there can be many
of these (and these timers do add up over all the kernel). The "5
second" wakeup isn't really timing sensitive; in addition even with
rounding it'll still happen every 5 seconds (with the exception of the
very first time, which is likely to be rounded up to somewhere closer
to 6 seconds)
(Ported from similar JBD patch made by Arjan van de Ven to
fs/jbd/transaction.c)
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch marks slab allocations by jbd2 as short-lived in support of
Mel Gorman's "Group short-lived and reclaimable kernel allocations"
patch. (Ported from similar changes made to fs/jbd/journal.c and
fs/jbd/revoke.c in Mel's patch.)
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The journal checksum feature adds two new flags i.e
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT and JBD2_FEATURE_COMPAT_CHECKSUM.
JBD2_FEATURE_CHECKSUM flag indicates that the commit block contains the
checksum for the blocks described by the descriptor blocks.
Due to checksums, writing of the commit record no longer needs to be
synchronous. Now commit record can be sent to disk without waiting for
descriptor blocks to be written to disk. This behavior is controlled
using JBD2_FEATURE_ASYNC_COMMIT flag. Older kernels/e2fsck should not be
able to recover the journal with _ASYNC_COMMIT hence it is made
incompat.
The commit header has been extended to hold the checksum along with the
type of the checksum.
For recovery in pass scan checksums are verified to ensure the sanity
and completeness(in case of _ASYNC_COMMIT) of every transaction.
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Girish Shilamkar <girish@clusterfs.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
The patch below updates the jbd stats patch to 2.6.20/jbd2.
The initial patch was posted by Alex Tomas in December 2005
(http://marc.info/?l=linux-ext4&m=113538565128617&w=2).
It provides statistics via procfs such as transaction lifetime and size.
Sometimes, investigating performance problems, i find useful to have
stats from jbd about transaction's lifetime, size, etc. here is a
patch for review and inclusion probably.
for example, stats after creation of 3M files in htree directory:
[root@bob ~]# cat /proc/fs/jbd/sda/history
R/C tid wait run lock flush log hndls block inlog ctime write drop close
R 261 8260 2720 0 0 750 9892 8170 8187
C 259 750 0 4885 1
R 262 20 2200 10 0 770 9836 8170 8187
R 263 30 2200 10 0 3070 9812 8170 8187
R 264 0 5000 10 0 1340 0 0 0
C 261 8240 3212 4957 0
R 265 8260 1470 0 0 4640 9854 8170 8187
R 266 0 5000 10 0 1460 0 0 0
C 262 8210 2989 4868 0
R 267 8230 1490 10 0 4440 9875 8171 8188
R 268 0 5000 10 0 1260 0 0 0
C 263 7710 2937 4908 0
R 269 7730 1470 10 0 3330 9841 8170 8187
R 270 0 5000 10 0 830 0 0 0
C 265 8140 3234 4898 0
C 267 720 0 4849 1
R 271 8630 2740 20 0 740 9819 8170 8187
C 269 800 0 4214 1
R 272 40 2170 10 0 830 9716 8170 8187
R 273 40 2280 0 0 3530 9799 8170 8187
R 274 0 5000 10 0 990 0 0 0
where,
R - line for transaction's life from T_RUNNING to T_FINISHED
C - line for transaction's checkpointing
tid - transaction's id
wait - for how long we were waiting for new transaction to start
(the longest period journal_start() took in this transaction)
run - real transaction's lifetime (from T_RUNNING to T_LOCKED
lock - how long we were waiting for all handles to close
(time the transaction was in T_LOCKED)
flush - how long it took to flush all data (data=ordered)
log - how long it took to write the transaction to the log
hndls - how many handles got to the transaction
block - how many blocks got to the transaction
inlog - how many blocks are written to the log (block + descriptors)
ctime - how long it took to checkpoint the transaction
write - how many blocks have been written during checkpointing
drop - how many blocks have been dropped during checkpointing
close - how many running transactions have been closed to checkpoint this one
all times are in msec.
[root@bob ~]# cat /proc/fs/jbd/sda/info
280 transaction, each upto 8192 blocks
average:
1633ms waiting for transaction
3616ms running transaction
5ms transaction was being locked
1ms flushing data (in ordered mode)
1799ms logging transaction
11781 handles per transaction
5629 blocks per transaction
5641 logged blocks per transaction
Signed-off-by: Johann Lombardi <johann.lombardi@bull.net>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Before we start committing a transaction, we call
__journal_clean_checkpoint_list() to cleanup transaction's written-back
buffers.
If this call happens to remove all of them (and there were already some
buffers), __journal_remove_checkpoint() will decide to free the transaction
because it isn't (yet) a committing transaction and soon we fail some
assertion - the transaction really isn't ready to be freed :).
We change the check in __journal_remove_checkpoint() to free only a
transaction in T_FINISHED state. The locking there is subtle though (as
everywhere in JBD ;(). We use j_list_lock to protect the check and a
subsequent call to __journal_drop_transaction() and do the same in the end
of journal_commit_transaction() which is the only place where a transaction
can get to T_FINISHED state.
Probably I'm too paranoid here and such locking is not really necessary -
checkpoint lists are processed only from log_do_checkpoint() where a
transaction must be already committed to be processed or from
__journal_clean_checkpoint_list() where kjournald itself calls it and thus
transaction cannot change state either. Better be safe if something
changes in future...
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mostly stolen from akpm's JBD cleanup patch.
- use `#ifdef foo' instead of `#if defined(foo)'
- Make journal_enable_debug __read_mostly just for the heck of it
- Make jbd_debugfs_dir and jbd_debug static
- debugfs_remove(NULL) is legal: remove unneeded tests
- remove unnecessary empty loops
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We should really call journal_abort() and not __journal_abort_hard() in
case of errors. The latter call does not record the error in the journal
superblock and thus filesystem won't be marked as with errors later (and
user could happily mount it without any warning).
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
JBD2: Replace slab allocations with page allocations
JBD2 allocate memory for committed_data and frozen_data from slab. However
JBD2 should not pass slab pages down to the block layer. Use page allocator
pages instead. This will also prepare JBD for the large blocksize patchset.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Looking at the current linus-git tree jbd_debug() define in
include/linux/jbd2.h
extern u8 journal_enable_debug;
#define jbd_debug(n, f, a...) \
do { \
if ((n) <= journal_enable_debug) { \
printk (KERN_DEBUG "(%s, %d): %s: ", \
__FILE__, __LINE__, __FUNCTION__); \
printk (f, ## a); \
} \
} while (0)
> fs/ext4/inode.c: In function âext4_write_inodeâ:
> fs/ext4/inode.c:2906: warning: comparison is always true due to limited
> range of data type
>
> fs/jbd2/recovery.c: In function âjbd2_journal_recoverâ:
> fs/jbd2/recovery.c:254: warning: comparison is always true due to
> limited range of data type
> fs/jbd2/recovery.c:257: warning: comparison is always true due to
> limited range of data type
>
> fs/jbd2/recovery.c: In function âjbd2_journal_skip_recoveryâ:
> fs/jbd2/recovery.c:301: warning: comparison is always true due to
> limited range of data type
>
Noticed all warnings are occurs when the debug level is 0. Then found
the "jbd2: Move jbd2-debug file to debugfs" patch
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0f49d5d019afa4e94253bfc92f0daca3badb990b
changed the jbd2_journal_enable_debug from int type to u8, makes the
jbd_debug comparision is always true when the debugging level is 0. Thus
the compile warning occurs.
Thought about changing the jbd2_journal_enable_debug data type back to
int, but can't, because the jbd2-debug is moved to debug fs, where
calling debugfs_create_u8() to create the debugfs entry needs the value
to be u8 type.
Even if we changed the data type back to int, the code is still buggy,
kernel should not print jbd2 debug message if the
jbd2_journal_enable_debug is set to 0. But this is not the case.
The fix is change the level of debugging to 1. The same should fixed in
ext3/JBD, but currently ext3 jbd-debug via /proc fs is broken, so we
probably should fix it all together.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Theodore Tso <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The jbd2-debug file used to be located in /proc/sys/fs/jbd2-debug, but it
incorrectly used create_proc_entry() instead of the sysctl routines, and
no proc entry was ever created.
Instead of fixing this we might as well move the jbd2-debug file to
debugfs which would be the preferred location for this kind of tunable.
The new location is now /sys/kernel/debug/jbd2/jbd2-debug.
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When the JBD code was forked to create the new JBD2 code base, the
references to CONFIG_JBD_DEBUG where never changed to
CONFIG_JBD2_DEBUG. This patch fixes that.
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Ingo Molnar