linux/fs/ext4, branch v3.16

ext4: fix potential null pointer dereference in ext4_free_inode

2014-07-12T20:11:42Z

Fix potential null pointer dereferencing problem caused by e43bb4e612 ("ext4: decrement free clusters/inodes counters when block group declared bad") Reported-by: Dan Carpenter Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan Signed-off-by: Theodore Ts'o Reviewed-by: Lukas Czerner

ext4: fix a potential deadlock in __ext4_es_shrink()

2014-07-12T19:32:24Z

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: stable@vger.kernel.org Cc: Zheng Liu

ext4: revert commit which was causing fs corruption after journal replays

2014-07-11T17:55:40Z

Commit 007649375f6af2 ("ext4: initialize multi-block allocator before checking block descriptors") causes the block group descriptor's count of the number of free blocks to become inconsistent with the number of free blocks in the allocation bitmap. This is a harmless form of fs corruption, but it causes the kernel to potentially remount the file system read-only, or to panic, depending on the file systems's error behavior. Thanks to Eric Whitney for his tireless work to reproduce and to find the guilty commit. Fixes: 007649375f6af2 ("ext4: initialize multi-block allocator before checking block descriptors" Cc: stable@vger.kernel.org # 3.15 Reported-by: David Jander Reported-by: Matteo Croce Tested-by: Eric Whitney Suggested-by: Eric Whitney Signed-off-by: Theodore Ts'o

ext4: disable synchronous transaction batching if max_batch_time==0

2014-07-05T23:18:22Z

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 Cc: stable@vger.kernel.org

ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()

2014-07-05T23:15:50Z

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 Cc: stable@vger.kernel.org

ext4: clarify error count warning messages

2014-07-05T22:40:52Z

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 Cc: stable@vger.kernel.org

ext4: fix unjournalled bg descriptor while initializing inode bitmap

2014-07-05T20:28:35Z

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 Cc: stable@vger.kernel.org

ext4: Fix hole punching for files with indirect blocks

2014-06-26T16:30:54Z

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. CC: stable@vger.kernel.org Fixes: 8bad6fc813a3a5300f51369c39d315679fd88c72 Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: Fix block zeroing when punching holes in indirect block files

2014-06-26T16:28:57Z

free_holes_block() passed local variable as a block pointer to ext4_clear_blocks(). Thus ext4_clear_blocks() zeroed out this local variable instead of proper place in inode / indirect block. We later zero out proper place in inode / indirect block but don't dirty the inode / buffer again which can lead to subtle issues (some changes e.g. to inode can be lost). Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: decrement free clusters/inodes counters when block group declared bad

2014-06-26T14:11:53Z

We should decrement free clusters counter when block bitmap is marked as corrupt and free inodes counter when the allocation bitmap is marked as corrupt to avoid misunderstanding due to incorrect available size in statfs result. User can get immediately ENOSPC error from write begin without reaching for the writepages. Cc: Darrick J. Wong Reported-by: Amit Sahrawat Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan