* Direct I/O via iomap (required the iomap-for-next branch from Darrick
as a prereq).
* Support for using dioread-nolock where the block size < page size.
* Support for encryption for file systems where the block size < page size.
* Rework of journal credits handling so a revoke-heavy workload will
not cause the journal to run out of space.
* Replace bit-spinlocks with spinlocks in jbd2
Also included were some bug fixes and cleanups, mostly to clean up
corner cases from fuzzed file systems and error path handling.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"This merge window saw the the following new featuers added to ext4:
- Direct I/O via iomap (required the iomap-for-next branch from
Darrick as a prereq).
- Support for using dioread-nolock where the block size < page size.
- Support for encryption for file systems where the block size < page
size.
- Rework of journal credits handling so a revoke-heavy workload will
not cause the journal to run out of space.
- Replace bit-spinlocks with spinlocks in jbd2
Also included were some bug fixes and cleanups, mostly to clean up
corner cases from fuzzed file systems and error path handling"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (59 commits)
ext4: work around deleting a file with i_nlink == 0 safely
ext4: add more paranoia checking in ext4_expand_extra_isize handling
jbd2: make jbd2_handle_buffer_credits() handle reserved handles
ext4: fix a bug in ext4_wait_for_tail_page_commit
ext4: bio_alloc with __GFP_DIRECT_RECLAIM never fails
ext4: code cleanup for get_next_id
ext4: fix leak of quota reservations
ext4: remove unused variable warning in parse_options()
ext4: Enable encryption for subpage-sized blocks
fs/buffer.c: support fscrypt in block_read_full_page()
ext4: Add error handling for io_end_vec struct allocation
jbd2: Fine tune estimate of necessary descriptor blocks
jbd2: Provide trace event for handle restarts
ext4: Reserve revoke credits for freed blocks
jbd2: Make credit checking more strict
jbd2: Rename h_buffer_credits to h_total_credits
jbd2: Reserve space for revoke descriptor blocks
jbd2: Drop jbd2_space_needed()
jbd2: Account descriptor blocks into t_outstanding_credits
jbd2: Factor out common parts of stopping and restarting a handle
...
Currently we reserve j_max_transaction_buffers / 32 for transaction
descriptor blocks. Now that revoke descriptors are accounted for
separately this estimate is unnecessarily high and we can actually
compute much tighter estimate. In the common case of 32k journal blocks
and 4k blocksize this actually reduces the amount of reserved descriptor
blocks from 256 to ~25 which allows us to fit more real data into a
transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-25-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Provide trace event for handle restarts to ease debugging.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-24-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Make checking of available credits in jbd2_journal_dirty_metadata() more
strict. There should be always enough credits in the handle to write all
potential revoke descriptors. Also we warn in case there are not enough
credits since this is a bug in the filesystem.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-22-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The credit counter now contains both buffer and revoke descriptor block
credits. Rename to counter to h_total_credits to reflect that. No
functional change.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-21-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Extend functions for starting, extending, and restarting transaction
handles to take number of revoke records handle must be able to
accommodate. These functions then make sure transaction has enough
credits to be able to store resulting revoke descriptor blocks. Also
revoke code tracks number of revoke records created by a handle to catch
situation where some place didn't reserve enough space for revoke
records. Similarly to standard transaction credits, space for unused
reserved revoke records is released when the handle is stopped.
On the ext4 side we currently take a simplistic approach of reserving
space for 1024 revoke records for any transaction. This grows amount of
credits reserved for each handle only by a few and is enough for any
normal workload so that we don't hit warnings in jbd2. We will refine
the logic in following commits.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-20-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The function is now just a trivial wrapper returning
journal->j_max_transaction_buffers. Drop it.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-19-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, journal descriptor blocks were not accounted in
transaction->t_outstanding_credits and we were just leaving some slack
space in the journal for them (in jbd2_log_space_left() and
jbd2_space_needed()). This is making proper accounting (and reservation
we want to add) of descriptor blocks difficult so switch to accounting
descriptor blocks in transaction->t_outstanding_credits and just reserve
the same amount of credits in t_outstanding credits for journal
descriptor blocks when creating transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-18-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2__journal_restart() has quite some code that is common with
jbd2_journal_stop(). Factor this functionality into stop_this_handle()
helper and use it from both functions. Note that this also drops
t_handle_lock protection from jbd2__journal_restart() as
jbd2_journal_stop() does the same thing without it.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-17-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When we drop last handle from a transaction and journal->j_barrier_count
> 0, jbd2_journal_stop() wakes up journal->j_wait_transaction_locked
wait queue. This looks pointless - wait for outstanding handles always
happens on journal->j_wait_updates waitqueue.
journal->j_wait_transaction_locked is used to wait for transaction state
changes and by start_this_handle() for waiting until
journal->j_barrier_count drops to 0. The first case is clearly
irrelevant here since only jbd2 thread changes transaction state. The
second case looks related but jbd2_journal_unlock_updates() is
responsible for the wakeup in this case. So just drop the wakeup.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-16-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If a transaction is larger than journal->j_max_transaction_buffers, that
is a bug and not a trigger for transaction commit. Also the very next
attempt to start new handle will start transaction commit anyway. So
just remove the pointless check. Arguably, we could start transaction
commit whenever the transaction size is *close* to
journal->j_max_transaction_buffers. This has a potential to reduce
latency of the next jbd2_journal_start() at the cost of somewhat smaller
transactions. However for this to have any effect, it would mean that
there isn't someone already waiting in jbd2_journal_start() which means
metadata load for the fs is pretty light anyway so probably this
optimization is not worth it.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-15-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Move code in jbd2_journal_stop() around a bit. It removes some
unnecessary code duplication and will make factoring out parts common
with jbd2__journal_restart() easier.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-14-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2 statistics counting number of blocks logged in a transaction was
wrong. It didn't count the commit block and more importantly it didn't
count revoke descriptor blocks. Make sure these get properly counted.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-13-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
With 32-bit block numbers, we don't allocate the array for journal
buffer heads large enough for corresponding descriptor tags to fill the
descriptor block. Thus we end up writing out half-full descriptor blocks
to the journal unnecessarily growing the transaction. Fix the logic to
allocate the array large enough.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2_journal_next_log_block() does not look at
transaction->t_outstanding_credits. Remove the misleading comment.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191105164437.32602-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
On PREEMPT_RT bit-spinlocks have the same semantics as on PREEMPT_RT=n,
i.e. they disable preemption. That means functions which are not safe to be
called in preempt disabled context on RT trigger a might_sleep() assert.
The journal head bit spinlock is mostly held for short code sequences with
trivial RT safe functionality, except for one place:
jbd2_journal_put_journal_head() invokes __journal_remove_journal_head()
with the journal head bit spinlock held. __journal_remove_journal_head()
invokes kmem_cache_free() which must not be called with preemption disabled
on RT.
Jan suggested to rework the removal function so the actual free happens
outside the bit-spinlocked region.
Split it into two parts:
- Do the sanity checks and the buffer head detach under the lock
- Do the actual free after dropping the lock
There is error case handling in the free part which needs to dereference
the b_size field of the now detached buffer head. Due to paranoia (caused
by ignorance) the size is retrieved in the detach function and handed into
the free function. Might be over-engineered, but better safe than sorry.
This makes the journal head bit-spinlock usage RT compliant and also avoids
nested locking which is not covered by lockdep.
Suggested-by: Jan Kara <jack@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-ext4@vger.kernel.org
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20190809124233.13277-8-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Bit-spinlocks are problematic on PREEMPT_RT if functions which might sleep
on RT, e.g. spin_lock(), alloc/free(), are invoked inside the lock held
region because bit spinlocks disable preemption even on RT.
A first attempt was to replace state lock with a spinlock placed in struct
buffer_head and make the locking conditional on PREEMPT_RT and
DEBUG_BIT_SPINLOCKS.
Jan pointed out that there is a 4 byte hole in struct journal_head where a
regular spinlock fits in and he would not object to convert the state lock
to a spinlock unconditionally.
Aside of solving the RT problem, this also gains lockdep coverage for the
journal head state lock (bit-spinlocks are not covered by lockdep as it's
hard to fit a lockdep map into a single bit).
The trivial change would have been to convert the jbd_*lock_bh_state()
inlines, but that comes with the downside that these functions take a
buffer head pointer which needs to be converted to a journal head pointer
which adds another level of indirection.
As almost all functions which use this lock have a journal head pointer
readily available, it makes more sense to remove the lock helper inlines
and write out spin_*lock() at all call sites.
Fixup all locking comments as well.
Suggested-by: Jan Kara <jack@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jan Kara <jack@suse.com>
Cc: linux-ext4@vger.kernel.org
Link: https://lore.kernel.org/r/20190809124233.13277-7-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2_journal_forget() jumps to 'not_jbd' branch which calls __bforget()
in cases where the buffer is clean which is pointless. In case of failed
assertion, it can be even argued that it is safer not to touch buffer's
dirty bits. Also logically it makes more sense to just jump to 'drop'
and that will make logic also simpler when we switch bh_state_lock to a
spinlock.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20190809124233.13277-6-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We have cleared both dirty & jbddirty bits from the bh. So there's no
difference between bforget() and brelse(). Thus there's no point jumping
to no_jbd branch.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20190809124233.13277-5-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
__jbd2_journal_unfile_buffer() and __jbd2_journal_refile_buffer() drop
transaction's jh reference when they remove jh from a transaction. This
will be however inconvenient once we move state lock into journal_head
itself as we still need to unlock it and we'd need to grab jh reference
just for that. Move dropping of jh reference out of these functions into
the few callers.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20190809124233.13277-4-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
journal_unmap_buffer() checks first whether the buffer head is a journal.
If so it takes locks and then invokes jbd2_journal_grab_journal_head()
followed by another check whether this is journal head buffer.
The double checking is pointless.
Replace the initial check with jbd2_journal_grab_journal_head() which
alredy checks whether the buffer head is actually a journal.
Allows also early access to the journal head pointer for the upcoming
conversion of state lock to a regular spinlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20190809124233.13277-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since ext4/ocfs2 are using jbd2_inode dirty range scoping APIs now,
jbd2_journal_inode_add_[write|wait] are not used any more, remove them.
Link: http://lkml.kernel.org/r/1562977611-8412-2-git-send-email-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Acked-by: Changwei Ge <chge@linux.alibaba.com>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
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>
This issue was found when I use ebpf to trace every jbd2
handle's running info in dioread_nolock case.
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When executing generic/388 on a ppc64le machine, we notice the following
call trace,
VFS: brelse: Trying to free free buffer
WARNING: CPU: 0 PID: 6637 at /root/repos/linux/fs/buffer.c:1195 __brelse+0x84/0xc0
Call Trace:
__brelse+0x80/0xc0 (unreliable)
invalidate_bh_lru+0x78/0xc0
on_each_cpu_mask+0xa8/0x130
on_each_cpu_cond_mask+0x130/0x170
invalidate_bh_lrus+0x44/0x60
invalidate_bdev+0x38/0x70
ext4_put_super+0x294/0x560
generic_shutdown_super+0xb0/0x170
kill_block_super+0x38/0xb0
deactivate_locked_super+0xa4/0xf0
cleanup_mnt+0x164/0x1d0
task_work_run+0x110/0x160
do_notify_resume+0x414/0x460
ret_from_except_lite+0x70/0x74
The warning happens because flush_descriptor() drops bh reference it
does not own. The bh reference acquired by
jbd2_journal_get_descriptor_buffer() is owned by the log_bufs list and
gets released when this list is processed. The reference for doing IO is
only acquired in write_dirty_buffer() later in flush_descriptor().
Reported-by: Harish Sriram <harish@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The journal_sync_buffer() function was never carried over from jbd to
jbd2. So get rid of the vestigal declaration of this (non-existent)
function.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Currently both journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() operate on the entire address space
of each of the inodes associated with a given journal entry. The
consequence of this is that if we have an inode where we are constantly
appending dirty pages we can end up waiting for an indefinite amount of
time in journal_finish_inode_data_buffers() while we wait for all the
pages under writeback to be written out.
The easiest way to cause this type of workload is do just dd from
/dev/zero to a file until it fills the entire filesystem. This can
cause journal_finish_inode_data_buffers() to wait for the duration of
the entire dd operation.
We can improve this situation by scoping each of the inode dirty ranges
associated with a given transaction. We do this via the jbd2_inode
structure so that the scoping is contained within jbd2 and so that it
follows the lifetime and locking rules for that structure.
This allows us to limit the writeback & wait in
journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() respectively to the dirty range for
a given struct jdb2_inode, keeping us from waiting forever if the inode
in question is still being appended to.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
There are some print format mistakes in debug messages. Fix them.
Signed-off-by: Gaowei Pu <pugaowei@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When failing from creating cache jbd2_inode_cache, we will destroy the
previously created cache jbd2_handle_cache twice. This patch fixes
this by moving each cache initialization/destruction to its own
separate, individual function.
Signed-off-by: Chengguang Xu <cgxu519@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
We hit a BUG at fs/buffer.c:3057 if we detached the nbd device
before unmounting ext4 filesystem.
The typical chain of events leading to the BUG:
jbd2_write_superblock
submit_bh
submit_bh_wbc
BUG_ON(!buffer_mapped(bh));
The block device is removed and all the pages are invalidated. JBD2
was trying to write journal superblock to the block device which is
no longer present.
Fix this by checking the journal superblock's buffer head prior to
submitting.
Reported-by: Eric Ren <renzhen@linux.alibaba.com>
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
At the beginning, nblocks has been assigned. There is no need
to repeat the assignment in the while loop, and remove it.
Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
In jbd2_get_transaction, a new transaction is initialized,
and set to the j_running_transaction. No need for a return
value, so remove it.
Also, adjust some comments to match the actual operation
of this function.
Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
In jbd2_journal_commit_transaction(), if we are in abort mode,
we may flush the buffer without setting descriptor block checksum
by goto start_journal_io. Then fs is mounted,
jbd2_descriptor_block_csum_verify() failed.
[ 271.379811] EXT4-fs (vdd): shut down requested (2)
[ 271.381827] Aborting journal on device vdd-8.
[ 271.597136] JBD2: Invalid checksum recovering block 22199 in log
[ 271.598023] JBD2: recovery failed
[ 271.598484] EXT4-fs (vdd): error loading journal
Fix this problem by keep setting descriptor block checksum if the
descriptor buffer is not NULL.
This checksum problem can be reproduced by xfstests generic/388.
Signed-off-by: luojiajun <luojiajun3@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
The jh pointer may be used uninitialized in the two cases below and the
compiler complain about it when enabling JBUFFER_TRACE macro, fix them.
In file included from fs/jbd2/transaction.c:19:0:
fs/jbd2/transaction.c: In function ‘jbd2_journal_get_undo_access’:
./include/linux/jbd2.h:1637:38: warning: ‘jh’ is used uninitialized in this function [-Wuninitialized]
#define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0)
^
fs/jbd2/transaction.c:1219:23: note: ‘jh’ was declared here
struct journal_head *jh;
^
In file included from fs/jbd2/transaction.c:19:0:
fs/jbd2/transaction.c: In function ‘jbd2_journal_dirty_metadata’:
./include/linux/jbd2.h:1637:38: warning: ‘jh’ may be used uninitialized in this function [-Wmaybe-uninitialized]
#define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0)
^
fs/jbd2/transaction.c:1332:23: note: ‘jh’ was declared here
struct journal_head *jh;
^
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
The functions jbd2_superblock_csum_verify() and
jbd2_superblock_csum_set() only get called from one location, so to
simplify things, fold them into their callers.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The jbd2 superblock is lockless now, so there is probably a race
condition between writing it so disk and modifing contents of it, which
may lead to checksum error. The following race is the one case that we
have captured.
jbd2 fsstress
jbd2_journal_commit_transaction
jbd2_journal_update_sb_log_tail
jbd2_write_superblock
jbd2_superblock_csum_set jbd2_journal_revoke
jbd2_journal_set_features(revork)
modify superblock
submit_bh(checksum incorrect)
Fix this by locking the buffer head before modifing it. We always
write the jbd2 superblock after we modify it, so this just means
calling the lock_buffer() a little earlier.
This checksum corruption problem can be reproduced by xfstests
generic/475.
Reported-by: zhangyi (F) <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We do not unmap and clear dirty flag when forgetting a buffer without
journal or does not belongs to any transaction, so the invalid dirty
data may still be written to the disk later. It's fine if the
corresponding block is never used before the next mount, and it's also
fine that we invoke clean_bdev_aliases() related functions to unmap
the block device mapping when re-allocating such freed block as data
block. But this logic is somewhat fragile and risky that may lead to
data corruption if we forget to clean bdev aliases. So, It's better to
discard dirty data during forget time.
We have been already handled all the cases of forgetting journalled
buffer, this patch deal with the remaining two cases.
- buffer is not journalled yet,
- buffer is journalled but doesn't belongs to any transaction.
We invoke __bforget() instead of __brelese() when forgetting an
un-journalled buffer in jbd2_journal_forget(). After this patch we can
remove all clean_bdev_aliases() related calls in ext4.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Now, we capture a data corruption problem on ext4 while we're truncating
an extent index block. Imaging that if we are revoking a buffer which
has been journaled by the committing transaction, the buffer's jbddirty
flag will not be cleared in jbd2_journal_forget(), so the commit code
will set the buffer dirty flag again after refile the buffer.
fsx kjournald2
jbd2_journal_commit_transaction
jbd2_journal_revoke commit phase 1~5...
jbd2_journal_forget
belongs to older transaction commit phase 6
jbddirty not clear __jbd2_journal_refile_buffer
__jbd2_journal_unfile_buffer
test_clear_buffer_jbddirty
mark_buffer_dirty
Finally, if the freed extent index block was allocated again as data
block by some other files, it may corrupt the file data after writing
cached pages later, such as during unmount time. (In general,
clean_bdev_aliases() related helpers should be invoked after
re-allocation to prevent the above corruption, but unfortunately we
missed it when zeroout the head of extra extent blocks in
ext4_ext_handle_unwritten_extents()).
This patch mark buffer as freed and set j_next_transaction to the new
transaction when it already belongs to the committing transaction in
jbd2_journal_forget(), so that commit code knows it should clear dirty
bits when it is done with the buffer.
This problem can be reproduced by xfstests generic/455 easily with
seeds (3246 3247 3248 3249).
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
This issue was found when I tried to put checkpoint work in a separate thread,
the deadlock below happened:
Thread1 | Thread2
__jbd2_log_wait_for_space |
jbd2_log_do_checkpoint (hold j_checkpoint_mutex)|
if (jh->b_transaction != NULL) |
... |
jbd2_log_start_commit(journal, tid); |jbd2_update_log_tail
| will lock j_checkpoint_mutex,
| but will be blocked here.
|
jbd2_log_wait_commit(journal, tid); |
wait_event(journal->j_wait_done_commit, |
!tid_gt(tid, journal->j_commit_sequence)); |
... |wake_up(j_wait_done_commit)
} |
then deadlock occurs, Thread1 will never be waken up.
To fix this issue, drop j_checkpoint_mutex in jbd2_log_do_checkpoint()
when we are going to wait for transaction commit.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
There is a statement that is indented with spaces, replace it with
a tab.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We can hold j_state_lock for writing at the beginning of
jbd2_journal_commit_transaction() for a rather long time (reportedly for
30 ms) due cleaning revoke bits of all revoked buffers under it. The
handling of revoke tables as well as cleaning of t_reserved_list, and
checkpoint lists does not need j_state_lock for anything. It is only
needed to prevent new handles from joining the transaction. Generally
T_LOCKED transaction state prevents new handles from joining the
transaction - except for reserved handles which have to allowed to join
while we wait for other handles to complete.
To prevent reserved handles from joining the transaction while cleaning
up lists, add new transaction state T_SWITCH and watch for it when
starting reserved handles. With this we can just drop the lock for
operations that don't need it.
Reported-and-tested-by: Adrian Hunter <adrian.hunter@intel.com>
Suggested-by: "Theodore Y. Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The code cleaning transaction's lists of checkpoint buffers has a bug
where it increases bh refcount only after releasing
journal->j_list_lock. Thus the following race is possible:
CPU0 CPU1
jbd2_log_do_checkpoint()
jbd2_journal_try_to_free_buffers()
__journal_try_to_free_buffer(bh)
...
while (transaction->t_checkpoint_io_list)
...
if (buffer_locked(bh)) {
<-- IO completes now, buffer gets unlocked -->
spin_unlock(&journal->j_list_lock);
spin_lock(&journal->j_list_lock);
__jbd2_journal_remove_checkpoint(jh);
spin_unlock(&journal->j_list_lock);
try_to_free_buffers(page);
get_bh(bh) <-- accesses freed bh
Fix the problem by grabbing bh reference before unlocking
journal->j_list_lock.
Fixes: dc6e8d669c ("jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint()")
Fixes: be1158cc61 ("jbd2: fold __process_buffer() into jbd2_log_do_checkpoint()")
Reported-by: syzbot+7f4a27091759e2fe7453@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2 is one of the few callers of current_kernel_time64(), which
is a wrapper around ktime_get_coarse_real_ts64(). This calls the
latter directly for consistency with the rest of the kernel that
is moving to the ktime_get_ family of time accessors.
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
maliciously crafted file system image can result in a kernel OOPS or
hang. At least one fix addresses an inline data bug could be
triggered by userspace without the need of a crafted file system
(although it does require that the inline data feature be enabled).
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 bugfixes from Ted Ts'o:
"Bug fixes for ext4; most of which relate to vulnerabilities where a
maliciously crafted file system image can result in a kernel OOPS or
hang.
At least one fix addresses an inline data bug could be triggered by
userspace without the need of a crafted file system (although it does
require that the inline data feature be enabled)"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: check superblock mapped prior to committing
ext4: add more mount time checks of the superblock
ext4: add more inode number paranoia checks
ext4: avoid running out of journal credits when appending to an inline file
jbd2: don't mark block as modified if the handle is out of credits
ext4: never move the system.data xattr out of the inode body
ext4: clear i_data in ext4_inode_info when removing inline data
ext4: include the illegal physical block in the bad map ext4_error msg
ext4: verify the depth of extent tree in ext4_find_extent()
ext4: only look at the bg_flags field if it is valid
ext4: make sure bitmaps and the inode table don't overlap with bg descriptors
ext4: always check block group bounds in ext4_init_block_bitmap()
ext4: always verify the magic number in xattr blocks
ext4: add corruption check in ext4_xattr_set_entry()
ext4: add warn_on_error mount option
Do not set the b_modified flag in block's journal head should not
until after we're sure that jbd2_journal_dirty_metadat() will not
abort with an error due to there not being enough space reserved in
the jbd2 handle.
Otherwise, future attempts to modify the buffer may lead a large
number of spurious errors and warnings.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
The kmem_cache_destroy() function already checks for null pointers, so
we can remove the check at the call site.
This patch also sets jbd2_handle_cache and jbd2_inode_cache to be NULL
after freeing them in jbd2_journal_destroy_handle_cache().
Signed-off-by: Wang Long <wanglong19@meituan.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
