linux/fs/ext4, branch v3.13

ext4: fix bigalloc regression

2014-01-06T19:00:23Z

Commit f5a44db5d2 introduced a regression on filesystems created with the bigalloc feature (cluster size > blocksize). It causes xfstests generic/006 and /013 to fail with an unexpected JBD2 failure and transaction abort that leaves the test file system in a read only state. Other xfstests run on bigalloc file systems are likely to fail as well. The cause is the accidental use of a cluster mask where a cluster offset was needed in ext4_ext_map_blocks(). Signed-off-by: Eric Whitney

ext4: add explicit casts when masking cluster sizes

2013-12-20T14:29:35Z

The missing casts can cause the high 64-bits of the physical blocks to be lost. Set up new macros which allows us to make sure the right thing happen, even if at some point we end up supporting larger logical block numbers. Thanks to the Emese Revfy and the PaX security team for reporting this issue. Reported-by: PaX Team Reported-by: Emese Revfy Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: fix deadlock when writing in ENOSPC conditions

2013-12-18T05:44:44Z

Akira-san has been reporting rare deadlocks of his machine when running xfstests test 269 on ext4 filesystem. The problem turned out to be in ext4_da_reserve_metadata() and ext4_da_reserve_space() which called ext4_should_retry_alloc() while holding i_data_sem. Since ext4_should_retry_alloc() can force a transaction commit, this is a lock ordering violation and leads to deadlocks. Fix the problem by just removing the retry loops. These functions should just report ENOSPC to the caller (e.g. ext4_da_write_begin()) and that function must take care of retrying after dropping all necessary locks. Reported-and-tested-by: Akira Fujita Reviewed-by: Zheng Liu Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: Do not reserve clusters when fs doesn't support extents

2013-12-09T02:11:59Z

When the filesystem doesn't support extents (like in ext2/3 compatibility modes), there is no need to reserve any clusters. Space estimates for writing are exact, hole punching doesn't need new metadata, and there are no unwritten extents to convert. This fixes a problem when filesystem still having some free space when accessed with a native ext2/3 driver suddently reports ENOSPC when accessed with ext4 driver. Reported-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Reviewed-by: Lukas Czerner Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: fix del_timer() misuse for ->s_err_report

2013-12-09T01:52:31Z

That thing should be del_timer_sync(); consider what happens if ext4_put_super() call of del_timer() happens to come just as it's getting run on another CPU. Since that timer reschedules itself to run next day, you are pretty much guaranteed that you'll end up with kfree'd scheduled timer, with usual fun consequences. AFAICS, that's -stable fodder all way back to 2010... [the second del_timer_sync() is almost certainly not needed, but it doesn't hurt either] Signed-off-by: Al Viro Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: check for overlapping extents in ext4_valid_extent_entries()

2013-12-04T02:22:21Z

A corrupted ext4 may have out of order leaf extents, i.e. extent: lblk 0--1023, len 1024, pblk 9217, flags: LEAF UNINIT extent: lblk 1000--2047, len 1024, pblk 10241, flags: LEAF UNINIT ^^^^ overlap with previous extent Reading such extent could hit BUG_ON() in ext4_es_cache_extent(). BUG_ON(end < lblk); The problem is that __read_extent_tree_block() tries to cache holes as well but assumes 'lblk' is greater than 'prev' and passes underflowed length to ext4_es_cache_extent(). Fix it by checking for overlapping extents in ext4_valid_extent_entries(). I hit this when fuzz testing ext4, and am able to reproduce it by modifying the on-disk extent by hand. Also add the check for (ee_block + len - 1) in ext4_valid_extent() to make sure the value is not overflow. Ran xfstests on patched ext4 and no regression. Cc: Lukáš Czerner Signed-off-by: Eryu Guan Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: fix use-after-free in ext4_mb_new_blocks

2013-12-03T23:10:28Z

ext4_mb_put_pa should hold pa->pa_lock before accessing pa->pa_count. While ext4_mb_use_preallocated checks pa->pa_deleted first and then increments pa->count later, ext4_mb_put_pa decrements pa->pa_count before holding pa->pa_lock and then sets pa->pa_deleted. * Free sequence ext4_mb_put_pa (1): atomic_dec_and_test pa->pa_count ext4_mb_put_pa (2): lock pa->pa_lock ext4_mb_put_pa (3): check pa->pa_deleted ext4_mb_put_pa (4): set pa->pa_deleted=1 ext4_mb_put_pa (5): unlock pa->pa_lock ext4_mb_put_pa (6): remove pa from a list ext4_mb_pa_callback: free pa * Use sequence ext4_mb_use_preallocated (1): iterate over preallocation ext4_mb_use_preallocated (2): lock pa->pa_lock ext4_mb_use_preallocated (3): check pa->pa_deleted ext4_mb_use_preallocated (4): increase pa->pa_count ext4_mb_use_preallocated (5): unlock pa->pa_lock ext4_mb_release_context: access pa * Use-after-free sequence [initial status] pa_deleted = 0, pa_count = 1> ext4_mb_use_preallocated (1): iterate over preallocation ext4_mb_use_preallocated (2): lock pa->pa_lock ext4_mb_use_preallocated (3): check pa->pa_deleted ext4_mb_put_pa (1): atomic_dec_and_test pa->pa_count [pa_count decremented] pa_deleted = 0, pa_count = 0> ext4_mb_use_preallocated (4): increase pa->pa_count [pa_count incremented] pa_deleted = 0, pa_count = 1> ext4_mb_use_preallocated (5): unlock pa->pa_lock ext4_mb_put_pa (2): lock pa->pa_lock ext4_mb_put_pa (3): check pa->pa_deleted ext4_mb_put_pa (4): set pa->pa_deleted=1 [race condition!] pa_deleted = 1, pa_count = 1> ext4_mb_put_pa (5): unlock pa->pa_lock ext4_mb_put_pa (6): remove pa from a list ext4_mb_pa_callback: free pa ext4_mb_release_context: access pa AddressSanitizer has detected use-after-free in ext4_mb_new_blocks Bug report: http://goo.gl/rG1On3 Signed-off-by: Junho Ryu Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: call ext4_error_inode() if jbd2_journal_dirty_metadata() fails

2013-12-02T14:31:36Z

While it's true that errors can only happen if there is a bug in jbd2_journal_dirty_metadata(), if a bug does happen, we need to halt the kernel or remount the file system read-only in order to avoid further data loss. The ext4_journal_abort_handle() function doesn't do any of this, and while it's likely that this call (since it doesn't adjust refcounts) will likely result in the file system eventually deadlocking since the current transaction will never be able to close, it's much cleaner to call let ext4's error handling system deal with this situation. There's a separate bug here which is that if certain jbd2 errors errors occur and file system is mounted errors=continue, the file system will probably eventually end grind to a halt as described above. But things have been this way in a long time, and usually when we have these sorts of errors it's pretty much a disaster --- and that's why the jbd2 layer aggressively retries memory allocations, which is the most likely cause of these jbd2 errors. Signed-off-by: "Theodore Ts'o" Reviewed-by: Jan Kara Cc: stable@vger.kernel.org

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2013-11-14T08:19:58Z

Pull ext4 changes from Ted Ts'o: "Ext4 updates for 3.13. Mostly bug fixes and cleanups" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: add prototypes for macro-generated functions ext4: return non-zero st_blocks for inline data ext4: use prandom_u32() instead of get_random_bytes() ext4: remove unreachable code after ext4_can_extents_be_merged() ext4: remove unreachable code in ext4_can_extents_be_merged() ext4: avoid bh leak in retry path of ext4_expand_extra_isize_ea() ext4: don't count free clusters from a corrupt block group ext4: fix FITRIM in no journal mode ext4: drop set but otherwise unused variable from ext4_add_dirent_to_inline() ext4: change ext4_read_inline_dir() to return 0 on success ext4: pair trace_ext4_writepages & trace_ext4_writepages_result ext4: add ratelimiting to ext4 messages ext4: fix performance regression in ext4_writepages ext4: fixup kerndoc annotation of mpage_map_and_submit_extent() ext4: fix assertion in ext4_add_complete_io()

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-11-13T06:34:18Z

Pull vfs updates from Al Viro: "All kinds of stuff this time around; some more notable parts: - RCU'd vfsmounts handling - new primitives for coredump handling - files_lock is gone - Bruce's delegations handling series - exportfs fixes plus misc stuff all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits) ecryptfs: ->f_op is never NULL locks: break delegations on any attribute modification locks: break delegations on link locks: break delegations on rename locks: helper functions for delegation breaking locks: break delegations on unlink namei: minor vfs_unlink cleanup locks: implement delegations locks: introduce new FL_DELEG lock flag vfs: take i_mutex on renamed file vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: don't use PARENT/CHILD lock classes for non-directories vfs: pull ext4's double-i_mutex-locking into common code exportfs: fix quadratic behavior in filehandle lookup exportfs: better variable name exportfs: move most of reconnect_path to helper function exportfs: eliminate unused "noprogress" counter exportfs: stop retrying once we race with rename/remove exportfs: clear DISCONNECTED on all parents sooner exportfs: more detailed comment for path_reconnect ...