linux-toradex.git/fs/ext4, branch v3.12.25

ext4: fix a potential deadlock in __ext4_es_shrink()

2014-07-18T13:51:27+00:00

commit 3f1f9b851311a76226140b55b1ea22111234a7c2 upstream.

This fixes the following lockdep complaint:

[ INFO: possible circular locking dependency detected ]
3.16.0-rc2-mm1+ #7 Tainted: G           O
-------------------------------------------------------
kworker/u24:0/4356 is trying to acquire lock:
 (&(&sbi->s_es_lru_lock)->rlock){+.+.-.}, at: [] __ext4_es_shrink+0x4f/0x2e0

but task is already holding lock:
 (&ei->i_es_lock){++++-.}, at: [] ext4_es_insert_extent+0x71/0x180

which lock already depends on the new lock.

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_es_lock);
                               lock(&(&sbi->s_es_lru_lock)->rlock);
                               lock(&ei->i_es_lock);
  lock(&(&sbi->s_es_lru_lock)->rlock);

 *** DEADLOCK ***

6 locks held by kworker/u24:0/4356:
 #0:  ("writeback"){.+.+.+}, at: [] process_one_work+0x180/0x560
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [] process_one_work+0x180/0x560
 #2:  (&type->s_umount_key#22){++++++}, at: [] grab_super_passive+0x44/0x90
 #3:  (jbd2_handle){+.+...}, at: [] start_this_handle+0x189/0x5f0
 #4:  (&ei->i_data_sem){++++..}, at: [] ext4_map_blocks+0x132/0x550
 #5:  (&ei->i_es_lock){++++-.}, at: [] ext4_es_insert_extent+0x71/0x180

stack backtrace:
CPU: 0 PID: 4356 Comm: kworker/u24:0 Tainted: G           O   3.16.0-rc2-mm1+ #7
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: writeback bdi_writeback_workfn (flush-253:0)
 ffffffff8213dce0 ffff880014b07538 ffffffff815df0bb 0000000000000007
 ffffffff8213e040 ffff880014b07588 ffffffff815db3dd ffff880014b07568
 ffff880014b07610 ffff88003b868930 ffff88003b868908 ffff88003b868930
Call Trace:
 [] dump_stack+0x4e/0x68
 [] print_circular_bug+0x1fb/0x20c
 [] __lock_acquire+0x163e/0x1d00
 [] ? retint_restore_args+0xe/0xe
 [] ? __slab_alloc+0x4a8/0x4ce
 [] ? __ext4_es_shrink+0x4f/0x2e0
 [] lock_acquire+0x87/0x120
 [] ? __ext4_es_shrink+0x4f/0x2e0
 [] ? ext4_es_free_extent+0x5d/0x70
 [] _raw_spin_lock+0x39/0x50
 [] ? __ext4_es_shrink+0x4f/0x2e0
 [] ? kmem_cache_alloc+0x18b/0x1a0
 [] __ext4_es_shrink+0x4f/0x2e0
 [] ext4_es_insert_extent+0xc8/0x180
 [] ext4_map_blocks+0x1c4/0x550
 [] ext4_writepages+0x6d4/0xd00
	...

Reported-by: Minchan Kim 
Signed-off-by: Theodore Ts'o 
Reported-by: Minchan Kim 
Cc: Zheng Liu 
Signed-off-by: Jiri Slaby

ext4: disable synchronous transaction batching if max_batch_time==0

2014-07-18T13:51:26+00:00

commit 5dd214248f94d430d70e9230bda72f2654ac88a8 upstream.

The mount manpage says of the max_batch_time option,

	This optimization can be turned off entirely
	by setting max_batch_time to 0.

But the code doesn't do that.  So fix the code to do
that.

Signed-off-by: Eric Sandeen 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()

2014-07-18T13:51:26+00:00

commit 94d4c066a4ff170a2671b1a9b153febbf36796f6 upstream.

We are spending a lot of time explaining to users what this error
means.  Let's try to improve the message to avoid this problem.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: clarify error count warning messages

2014-07-18T13:51:25+00:00

commit ae0f78de2c43b6fadd007c231a352b13b5be8ed2 upstream.

Make it clear that values printed are times, and that it is error
since last fsck. Also add note about fsck version required.

Signed-off-by: Pavel Machek 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Signed-off-by: Jiri Slaby

ext4: fix unjournalled bg descriptor while initializing inode bitmap

2014-07-18T13:51:25+00:00

commit 61c219f5814277ecb71d64cb30297028d6665979 upstream.

The first time that we allocate from an uninitialized inode allocation
bitmap, if the block allocation bitmap is also uninitalized, we need
to get write access to the block group descriptor before we start
modifying the block group descriptor flags and updating the free block
count, etc.  Otherwise, there is the potential of a bad journal
checksum (if journal checksums are enabled), and of the file system
becoming inconsistent if we crash at exactly the wrong time.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: Fix hole punching for files with indirect blocks

2014-07-18T13:51:05+00:00

commit a93cd4cf86466caa49cfe64607bea7f0bde3f916 upstream.

Hole punching code for files with indirect blocks wrongly computed
number of blocks which need to be cleared when traversing the indirect
block tree. That could result in punching more blocks than actually
requested and thus effectively cause a data loss. For example:

fallocate -n -p 10240000 4096

will punch the range 10240000 - 12632064 instead of the range 1024000 -
10244096. Fix the calculation.

Fixes: 8bad6fc813a3a5300f51369c39d315679fd88c72
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: Fix buffer double free in ext4_alloc_branch()

2014-07-18T13:51:04+00:00

commit c5c7b8ddfbf8cb3b2291e515a34ab1b8982f5a2d upstream.

Error recovery in ext4_alloc_branch() calls ext4_forget() even for
buffer corresponding to indirect block it did not allocate. This leads
to brelse() being called twice for that buffer (once from ext4_forget()
and once from cleanup in ext4_ind_map_blocks()) leading to buffer use
count misaccounting. Eventually (but often much later because there
are other users of the buffer) we will see messages like:
VFS: brelse: Trying to free free buffer

Another manifestation of this problem is an error:
JBD2 unexpected failure: jbd2_journal_revoke: !buffer_revoked(bh);
inconsistent data on disk

The fix is easy - don't forget buffer we did not allocate. Also add an
explanatory comment because the indexing at ext4_alloc_branch() is
somewhat subtle.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix wrong assert in ext4_mb_normalize_request()

2014-07-02T10:06:16+00:00

commit b5b60778558cafad17bbcbf63e0310bd3c68eb17 upstream.

The variable "size" is expressed as number of blocks and not as
number of clusters, this could trigger a kernel panic when using
ext4 with the size of a cluster different from the size of a block.

Signed-off-by: Maurizio Lombardi 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix zeroing of page during writeback

2014-07-02T10:06:16+00:00

commit eeece469dedadf3918bad50ad80f4616a0064e90 upstream.

Tail of a page straddling inode size must be zeroed when being written
out due to POSIX requirement that modifications of mmaped page beyond
inode size must not be written to the file. ext4_bio_write_page() did
this only for blocks fully beyond inode size but didn't properly zero
blocks partially beyond inode size. Fix this.

The problem has been uncovered by mmap_11-4 test in openposix test suite
(part of LTP).

Reported-by: Xiaoguang Wang 
Fixes: 5a0dc7365c240
Fixes: bd2d0210cf22f
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix data integrity sync in ordered mode

2014-07-02T10:06:15+00:00

commit 1c8349a17137b93f0a83f276c764a6df1b9a116e upstream.

When we perform a data integrity sync we tag all the dirty pages with
PAGECACHE_TAG_TOWRITE at start of ext4_da_writepages.  Later we check
for this tag in write_cache_pages_da and creates a struct
mpage_da_data containing contiguously indexed pages tagged with this
tag and sync these pages with a call to mpage_da_map_and_submit.  This
process is done in while loop until all the PAGECACHE_TAG_TOWRITE
pages are synced. We also do journal start and stop in each iteration.
journal_stop could initiate journal commit which would call
ext4_writepage which in turn will call ext4_bio_write_page even for
delayed OR unwritten buffers. When ext4_bio_write_page is called for
such buffers, even though it does not sync them but it clears the
PAGECACHE_TAG_TOWRITE of the corresponding page and hence these pages
are also not synced by the currently running data integrity sync. We
will end up with dirty pages although sync is completed.

This could cause a potential data loss when the sync call is followed
by a truncate_pagecache call, which is exactly the case in
collapse_range.  (It will cause generic/127 failure in xfstests)

To avoid this issue, we can use set_page_writeback_keepwrite instead of
set_page_writeback, which doesn't clear TOWRITE tag.

Signed-off-by: Namjae Jeon 
Signed-off-by: Ashish Sangwan 
Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Jan Kara 
Signed-off-by: Jiri Slaby