linux-toradex.git/fs/jbd2, branch colibri

jbd/jbd2: validate sb->s_first in journal_get_superblock()

2011-12-21T20:58:31+00:00

commit 8762202dd0d6e46854f786bdb6fb3780a1625efe upstream.

I hit a J_ASSERT(blocknr != 0) failure in cleanup_journal_tail() when
mounting a fsfuzzed ext3 image. It turns out that the corrupted ext3
image has s_first = 0 in journal superblock, and the 0 is passed to
journal->j_head in journal_reset(), then to blocknr in
cleanup_journal_tail(), in the end the J_ASSERT failed.

So validate s_first after reading journal superblock from disk in
journal_get_superblock() to ensure s_first is valid.

The following script could reproduce it:

fstype=ext3
blocksize=1024
img=$fstype.img
offset=0
found=0
magic="c0 3b 39 98"

dd if=/dev/zero of=$img bs=1M count=8
mkfs -t $fstype -b $blocksize -F $img
filesize=`stat -c %s $img`
while [ $offset -lt $filesize ]
do
        if od -j $offset -N 4 -t x1 $img | grep -i "$magic";then
                echo "Found journal: $offset"
                found=1
                break
        fi
        offset=`echo "$offset+$blocksize" | bc`
done

if [ $found -ne 1 ];then
        echo "Magic \"$magic\" not found"
        exit 1
fi

dd if=/dev/zero of=$img seek=$(($offset+23)) conv=notrunc bs=1 count=1

mkdir -p ./mnt
mount -o loop $img ./mnt

Cc: Jan Kara 
Signed-off-by: Eryu Guan 
Signed-off-by: "Theodore Ts'o" 
Cc: Moritz Mühlenhoff 
Signed-off-by: Greg Kroah-Hartman

jbd2: remove jbd2_dev_to_name() from jbd2 tracepoints

2011-07-11T02:05:08+00:00

Using function calls in TP_printk causes perf heartburn, so print the
MAJOR/MINOR device numbers instead.

Signed-off-by: "Theodore Ts'o"

jbd2: use WRITE_SYNC in journal checkpoint

2011-06-27T16:36:29+00:00

In journal checkpoint, we write the buffer and wait for its finish.
But in cfq, the async queue has a very low priority, and in our test,
if there are too many sync queues and every queue is filled up with
requests, the write request will be delayed for quite a long time and
all the tasks which are waiting for journal space will end with errors like:

INFO: task attr_set:3816 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
attr_set      D ffff880028393480     0  3816      1 0x00000000
 ffff8802073fbae8 0000000000000086 ffff8802140847c8 ffff8800283934e8
 ffff8802073fb9d8 ffffffff8103e456 ffff8802140847b8 ffff8801ed728080
 ffff8801db4bc080 ffff8801ed728450 ffff880028393480 0000000000000002
Call Trace:
 [] ? __dequeue_entity+0x33/0x38
 [] ? need_resched+0x23/0x2d
 [] ? thread_return+0xa2/0xbc
 [] ? jbd2_journal_dirty_metadata+0x116/0x126 [jbd2]
 [] ? jbd2_journal_dirty_metadata+0x116/0x126 [jbd2]
 [] __mutex_lock_common+0x14e/0x1a9
 [] ? brelse+0x13/0x15 [ext4]
 [] __mutex_lock_slowpath+0x19/0x1b
 [] mutex_lock+0x1b/0x32
 [] __jbd2_journal_insert_checkpoint+0xe3/0x20c [jbd2]
 [] start_this_handle+0x438/0x527 [jbd2]
 [] ? autoremove_wake_function+0x0/0x3e
 [] jbd2_journal_start+0xa1/0xcc [jbd2]
 [] ext4_journal_start_sb+0x57/0x81 [ext4]
 [] ext4_xattr_set+0x6c/0xe3 [ext4]
 [] ext4_xattr_user_set+0x42/0x4b [ext4]
 [] generic_setxattr+0x6b/0x76
 [] __vfs_setxattr_noperm+0x47/0xc0
 [] vfs_setxattr+0x7f/0x9a
 [] setxattr+0xb5/0xe8
 [] ? do_filp_open+0x571/0xa6e
 [] sys_fsetxattr+0x6b/0x91
 [] system_call_fastpath+0x16/0x1b

So this patch tries to use WRITE_SYNC in __flush_batch so that the request will
be moved into sync queue and handled by cfq timely. We also use the new plug,
sot that all the WRITE_SYNC requests can be given as a whole when we unplug it.

Signed-off-by: Tao Ma 
Signed-off-by: "Theodore Ts'o" 
Cc: Jan Kara 
Reported-by: Robin Dong

jbd2: Fix oops in jbd2_journal_remove_journal_head()

2011-06-13T19:38:22+00:00

jbd2_journal_remove_journal_head() can oops when trying to access
journal_head returned by bh2jh(). This is caused for example by the
following race:

	TASK1					TASK2
  jbd2_journal_commit_transaction()
    ...
    processing t_forget list
      __jbd2_journal_refile_buffer(jh);
      if (!jh->b_transaction) {
        jbd_unlock_bh_state(bh);
					jbd2_journal_try_to_free_buffers()
					  jbd2_journal_grab_journal_head(bh)
					  jbd_lock_bh_state(bh)
					  __journal_try_to_free_buffer()
					  jbd2_journal_put_journal_head(jh)
        jbd2_journal_remove_journal_head(bh);

jbd2_journal_put_journal_head() in TASK2 sees that b_jcount == 0 and
buffer is not part of any transaction and thus frees journal_head
before TASK1 gets to doing so. Note that even buffer_head can be
released by try_to_free_buffers() after
jbd2_journal_put_journal_head() which adds even larger opportunity for
oops (but I didn't see this happen in reality).

Fix the problem by making transactions hold their own journal_head
reference (in b_jcount). That way we don't have to remove journal_head
explicitely via jbd2_journal_remove_journal_head() and instead just
remove journal_head when b_jcount drops to zero. The result of this is
that [__]jbd2_journal_refile_buffer(),
[__]jbd2_journal_unfile_buffer(), and
__jdb2_journal_remove_checkpoint() can free journal_head which needs
modification of a few callers. Also we have to be careful because once
journal_head is removed, buffer_head might be freed as well. So we
have to get our own buffer_head reference where it matters.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"

jbd2: Remove obsolete parameters in the comments for some jbd2 functions

2011-06-13T02:44:10+00:00

credits isn't a parameter for jbd2_journal_get_write_access and
jbd2_journal_get_undo_access. So remove the corresponding comments.

Acked-by: Jan Kara 
Cc: Randy Dunlap 
Signed-off-by: Tao Ma 
Signed-off-by: "Theodore Ts'o"

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2011-05-26T16:53:20+00:00

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (61 commits)
  jbd2: Add MAINTAINERS entry
  jbd2: fix a potential leak of a journal_head on an error path
  ext4: teach ext4_ext_split to calculate extents efficiently
  ext4: Convert ext4 to new truncate calling convention
  ext4: do not normalize block requests from fallocate()
  ext4: enable "punch hole" functionality
  ext4: add "punch hole" flag to ext4_map_blocks()
  ext4: punch out extents
  ext4: add new function ext4_block_zero_page_range()
  ext4: add flag to ext4_has_free_blocks
  ext4: reserve inodes and feature code for 'quota' feature
  ext4: add support for multiple mount protection
  ext4: ensure f_bfree returned by ext4_statfs() is non-negative
  ext4: protect bb_first_free in ext4_trim_all_free() with group lock
  ext4: only load buddy bitmap in ext4_trim_fs() when it is needed
  jbd2: Fix comment to match the code in jbd2__journal_start()
  ext4: fix waiting and sending of a barrier in ext4_sync_file()
  jbd2: Add function jbd2_trans_will_send_data_barrier()
  jbd2: fix sending of data flush on journal commit
  ext4: fix ext4_ext_fiemap_cb() to handle blocks before request range correctly
  ...

jbd2: fix a potential leak of a journal_head on an error path

2011-05-25T21:43:48+00:00

drop jh->b_jcount in error path

Signed-off-by: Ding Dinghua 
Signed-off-by: "Theodore Ts'o"

jbd2: Fix comment to match the code in jbd2__journal_start()

2011-05-24T21:09:58+00:00

jbd2__journal_start() returns an ERR_PTR() value rather than NULL on
failure.

Signed-off-by: Eryu Guan 
Signed-off-by: "Theodore Ts'o"

jbd2: Add function jbd2_trans_will_send_data_barrier()

2011-05-24T15:59:18+00:00

Provide a function which returns whether a transaction with given tid
will send a flush to the filesystem device.  The function will be used
by ext4 to detect whether fsync needs to send a separate flush or not.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"

jbd2: fix sending of data flush on journal commit

2011-05-24T15:52:40+00:00

In data=ordered mode, it's theoretically possible (however rare) that
an inode is filed to transaction's t_inode_list and a flusher thread
writes all the data and inode is reclaimed before the transaction
starts to commit.  In such a case, we could erroneously omit sending a
flush to file system device when it is different from the journal
device (because data can still be in disk cache only).

Fix the problem by setting a flag in a transaction when some inode is added
to it and then send disk flush in the commit code when the flag is set.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"