linux-stable.git/fs/jbd2, branch v4.4.232

jbd2: improve comments about freeing data buffers whose page mapping is NULL

2020-04-24T05:57:19+00:00

commit 780f66e59231fcf882f36c63f287252ee47cc75a upstream.

Improve comments in jbd2_journal_commit_transaction() to describe why
we don't need to clear the buffer_mapped bit for freeing file mapping
buffers whose page mapping is NULL.

Link: https://lore.kernel.org/r/20200217112706.20085-1-yi.zhang@huawei.com
Fixes: c96dceeabf76 ("jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer")
Suggested-by: Jan Kara 
Reviewed-by: Jan Kara 
Signed-off-by: zhangyi (F) 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

jbd2: fix data races at struct journal_head

2020-03-20T08:06:34+00:00

[ Upstream commit 6c5d911249290f41f7b50b43344a7520605b1acb ]

journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara 
Signed-off-by: Qian Cai 
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

jbd2: switch to use jbd2_journal_abort() when failed to submit the commit record

2020-02-28T14:39:06+00:00

[ Upstream commit d0a186e0d3e7ac05cc77da7c157dae5aa59f95d9 ]

We invoke jbd2_journal_abort() to abort the journal and record errno
in the jbd2 superblock when committing journal transaction besides the
failure on submitting the commit record. But there is no need for the
case and we can also invoke jbd2_journal_abort() instead of
__jbd2_journal_abort_hard().

Fixes: 818d276ceb83a ("ext4: Add the journal checksum feature")
Signed-off-by: zhangyi (F) 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20191204124614.45424-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4, jbd2: ensure panic when aborting with zero errno

2020-02-28T14:38:55+00:00

[ Upstream commit 51f57b01e4a3c7d7bdceffd84de35144e8c538e7 ]

JBD2_REC_ERR flag used to indicate the errno has been updated when jbd2
aborted, and then __ext4_abort() and ext4_handle_error() can invoke
panic if ERRORS_PANIC is specified. But if the journal has been aborted
with zero errno, jbd2_journal_abort() didn't set this flag so we can
no longer panic. Fix this by always record the proper errno in the
journal superblock.

Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock")
Signed-off-by: zhangyi (F) 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20191204124614.45424-3-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

jbd2: clear JBD2_ABORT flag before journal_reset to update log tail info when load journal

2020-02-28T14:38:55+00:00

[ Upstream commit a09decff5c32060639a685581c380f51b14e1fc2 ]

If the journal is dirty when the filesystem is mounted, jbd2 will replay
the journal but the journal superblock will not be updated by
journal_reset() because JBD2_ABORT flag is still set (it was set in
journal_init_common()). This is problematic because when a new transaction
is then committed, it will be recorded in block 1 (journal->j_tail was set
to 1 in journal_reset()). If unclean shutdown happens again before the
journal superblock is updated, the new recorded transaction will not be
replayed during the next mount (because of stale sb->s_start and
sb->s_sequence values) which can lead to filesystem corruption.

Fixes: 85e0c4e89c1b ("jbd2: if the journal is aborted then don't allow update of the log tail")
Signed-off-by: Kai Li 
Link: https://lore.kernel.org/r/20200111022542.5008-1-li.kai4@h3c.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer

2020-02-28T14:38:50+00:00

[ Upstream commit c96dceeabf765d0b1b1f29c3bf50a5c01315b820 ]

Commit 904cdbd41d74 ("jbd2: clear dirty flag when revoking a buffer from
an older transaction") set the BH_Freed flag when forgetting a metadata
buffer which belongs to the committing transaction, it indicate the
committing process clear dirty bits when it is done with the buffer. But
it also clear the BH_Mapped flag at the same time, which may trigger
below NULL pointer oops when block_size < PAGE_SIZE.

rmdir 1             kjournald2                 mkdir 2
                    jbd2_journal_commit_transaction
		    commit transaction N
jbd2_journal_forget
set_buffer_freed(bh1)
                    jbd2_journal_commit_transaction
                     commit transaction N+1
                     ...
                     clear_buffer_mapped(bh1)
                                               ext4_getblk(bh2 ummapped)
                                               ...
                                               grow_dev_page
                                                init_page_buffers
                                                 bh1->b_private=NULL
                                                 bh2->b_private=NULL
                     jbd2_journal_put_journal_head(jh1)
                      __journal_remove_journal_head(hb1)
		       jh1 is NULL and trigger oops

*) Dir entry block bh1 and bh2 belongs to one page, and the bh2 has
   already been unmapped.

For the metadata buffer we forgetting, we should always keep the mapped
flag and clear the dirty flags is enough, so this patch pick out the
these buffers and keep their BH_Mapped flag.

Link: https://lore.kernel.org/r/20200213063821.30455-3-yi.zhang@huawei.com
Fixes: 904cdbd41d74 ("jbd2: clear dirty flag when revoking a buffer from an older transaction")
Reviewed-by: Jan Kara 
Signed-off-by: zhangyi (F) 
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org
Signed-off-by: Sasha Levin

jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()

2020-02-28T14:38:50+00:00

[ Upstream commit 6a66a7ded12baa6ebbb2e3e82f8cb91382814839 ]

There is no need to delay the clearing of b_modified flag to the
transaction committing time when unmapping the journalled buffer, so
just move it to the journal_unmap_buffer().

Link: https://lore.kernel.org/r/20200213063821.30455-2-yi.zhang@huawei.com
Reviewed-by: Jan Kara 
Signed-off-by: zhangyi (F) 
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org
Signed-off-by: Sasha Levin

jbd2: Fix statistics for the number of logged blocks

2020-01-04T12:34:28+00:00

[ Upstream commit 015c6033068208d6227612c878877919f3fcf6b6 ]

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 
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20191105164437.32602-13-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

jbd2: fix compile warning when using JBUFFER_TRACE

2019-03-23T07:44:37+00:00

commit 01215d3edb0f384ddeaa5e4a22c1ae5ff634149f upstream.

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) 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Reviewed-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

jbd2: clear dirty flag when revoking a buffer from an older transaction

2019-03-23T07:44:37+00:00

commit 904cdbd41d749a476863a0ca41f6f396774f26e4 upstream.

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) 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman