linux/fs/ext4, branch v4.5

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2016-03-10T03:33:05Z

Pull ext4 fix from Ted Ts'o: "This fixes a regression which crept in v4.5-rc5" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: iterate over buffer heads correctly in move_extent_per_page()

ext4: iterate over buffer heads correctly in move_extent_per_page()

2016-03-10T02:37:53Z

In commit bcff24887d00 ("ext4: don't read blocks from disk after extents being swapped") bh is not updated correctly in the for loop and wrong data has been written to disk. generic/324 catches this on sub-page block size ext4. Fixes: bcff24887d00 ("ext4: don't read blocks from disk after extentsbeing swapped") Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o

Merge branch 'akpm' (patches from Andrew)

2016-02-27T20:46:16Z

Merge fixes from Andrew Morton: "10 fixes" * emailed patches from Andrew Morton : dax: move writeback calls into the filesystems dax: give DAX clearing code correct bdev ext4: online defrag not supported with DAX ext2, ext4: only set S_DAX for regular inodes block: disable block device DAX by default ocfs2: unlock inode if deleting inode from orphan fails mm: ASLR: use get_random_long() drivers: char: random: add get_random_long() mm: numa: quickly fail allocations for NUMA balancing on full nodes mm: thp: fix SMP race condition between THP page fault and MADV_DONTNEED

ext2, ext4: fix issue with missing journal entry in ext4_dax_mkwrite()

2016-02-27T19:01:16Z

As it is currently written ext4_dax_mkwrite() assumes that the call into __dax_mkwrite() will not have to do a block allocation so it doesn't create a journal entry. For a read that creates a zero page to cover a hole followed by a write that actually allocates storage this is incorrect. The ext4_dax_mkwrite() -> __dax_mkwrite() -> __dax_fault() path calls get_blocks() to allocate storage. Fix this by having the ->page_mkwrite fault handler call ext4_dax_fault() as this function already has all the logic needed to allocate a journal entry and call __dax_fault(). Also update the ext2 fault handlers in this same way to remove duplicate code and keep the logic between ext2 and ext4 the same. Reviewed-by: Jan Kara Signed-off-by: Ross Zwisler Signed-off-by: Theodore Ts'o

dax: move writeback calls into the filesystems

2016-02-27T18:28:52Z

Previously calls to dax_writeback_mapping_range() for all DAX filesystems (ext2, ext4 & xfs) were centralized in filemap_write_and_wait_range(). dax_writeback_mapping_range() needs a struct block_device, and it used to get that from inode->i_sb->s_bdev. This is correct for normal inodes mounted on ext2, ext4 and XFS filesystems, but is incorrect for DAX raw block devices and for XFS real-time files. Instead, call dax_writeback_mapping_range() directly from the filesystem ->writepages function so that it can supply us with a valid block device. This also fixes DAX code to properly flush caches in response to sync(2). Signed-off-by: Ross Zwisler Signed-off-by: Jan Kara Cc: Al Viro Cc: Dan Williams Cc: Dave Chinner Cc: Jens Axboe Cc: Matthew Wilcox Cc: Theodore Ts'o Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ext4: online defrag not supported with DAX

2016-02-27T18:28:52Z

Online defrag operations for ext4 are hard coded to use the page cache. See ext4_ioctl() -> ext4_move_extents() -> move_extent_per_page() When combined with DAX I/O, which circumvents the page cache, this can result in data corruption. This was observed with xfstests ext4/307 and ext4/308. Fix this by only allowing online defrag for non-DAX files. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara Cc: Theodore Ts'o Cc: Al Viro Cc: Dan Williams Cc: Dave Chinner Cc: Jens Axboe Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ext2, ext4: only set S_DAX for regular inodes

2016-02-27T18:28:52Z

When S_DAX is set on an inode we assume that if there are pages attached to the mapping (mapping->nrpages != 0), those pages are clean zero pages that were used to service reads from holes. Any dirty data associated with the inode should be in the form of DAX exceptional entries (mapping->nrexceptional) that is written back via dax_writeback_mapping_range(). With the current code, though, this isn't always true. For example, ext2 and ext4 directory inodes can have S_DAX set, but have their dirty data stored as dirty page cache entries. For these types of inodes, having S_DAX set doesn't really make sense since their I/O doesn't actually happen through the DAX code path. Instead, only allow S_DAX to be set for regular inodes for ext2 and ext4. This allows us to have strict DAX vs non-DAX paths in the writeback code. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara Cc: Theodore Ts'o Cc: Al Viro Cc: Dan Williams Cc: Dave Chinner Cc: Jens Axboe Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ext4: fix crashes in dioread_nolock mode

2016-02-19T05:33:21Z

Competing overwrite DIO in dioread_nolock mode will just overwrite pointer to io_end in the inode. This may result in data corruption or extent conversion happening from IO completion interrupt because we don't properly set buffer_defer_completion() when unlocked DIO races with locked DIO to unwritten extent. Since unlocked DIO doesn't need io_end for anything, just avoid allocating it and corrupting pointer from inode for locked DIO. A cleaner fix would be to avoid these games with io_end pointer from the inode but that requires more intrusive changes so we leave that for later. Cc: stable@vger.kernel.org Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: fix bh->b_state corruption

2016-02-19T05:18:25Z

ext4 can update bh->b_state non-atomically in _ext4_get_block() and ext4_da_get_block_prep(). Usually this is fine since bh is just a temporary storage for mapping information on stack but in some cases it can be fully living bh attached to a page. In such case non-atomic update of bh->b_state can race with an atomic update which then gets lost. Usually when we are mapping bh and thus updating bh->b_state non-atomically, nobody else touches the bh and so things work out fine but there is one case to especially worry about: ext4_finish_bio() uses BH_Uptodate_Lock on the first bh in the page to synchronize handling of PageWriteback state. So when blocksize < pagesize, we can be atomically modifying bh->b_state of a buffer that actually isn't under IO and thus can race e.g. with delalloc trying to map that buffer. The result is that we can mistakenly set / clear BH_Uptodate_Lock bit resulting in the corruption of PageWriteback state or missed unlock of BH_Uptodate_Lock. Fix the problem by always updating bh->b_state bits atomically. CC: stable@vger.kernel.org Reported-by: Nikolay Borisov Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o

ext4: fix memleak in ext4_readdir()

2016-02-16T05:20:19Z

When ext4_bread() fails, fname_crypto_str remains allocated after return. Fix that. Signed-off-by: Kirill Tkhai Signed-off-by: Theodore Ts'o CC: Dmitry Monakhov