linux.git/fs/ext4/inline.c, branch v5.17

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

2022-02-06T18:34:45+00:00

Pull ext4 fixes from Ted Ts'o:
 "Various bug fixes for ext4 fast commit and inline data handling.

  Also fix regression introduced as part of moving to the new mount API"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  fs/ext4: fix comments mentioning i_mutex
  ext4: fix incorrect type issue during replay_del_range
  jbd2: fix kernel-doc descriptions for jbd2_journal_shrink_{scan,count}()
  ext4: fix potential NULL pointer dereference in ext4_fill_super()
  jbd2: refactor wait logic for transaction updates into a common function
  jbd2: cleanup unused functions declarations from jbd2.h
  ext4: fix error handling in ext4_fc_record_modified_inode()
  ext4: remove redundant max inline_size check in ext4_da_write_inline_data_begin()
  ext4: fix error handling in ext4_restore_inline_data()
  ext4: fast commit may miss file actions
  ext4: fast commit may not fallback for ineligible commit
  ext4: modify the logic of ext4_mb_new_blocks_simple
  ext4: prevent used blocks from being allocated during fast commit replay

ext4: remove redundant max inline_size check in ext4_da_write_inline_data_begin()

2022-02-03T15:57:30+00:00

ext4_prepare_inline_data() already checks for ext4_get_max_inline_size()
and returns -ENOSPC. So there is no need to check it twice within
ext4_da_write_inline_data_begin(). This patch removes the extra check.

It also makes it more clean.

No functionality change in this patch.

Signed-off-by: Ritesh Harjani 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/cdd1654128d5105550c65fd13ca5da53b2162cc4.1642416995.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: fix error handling in ext4_restore_inline_data()

2022-02-03T15:57:20+00:00

While running "./check -I 200 generic/475" it sometimes gives below
kernel BUG(). Ideally we should not call ext4_write_inline_data() if
ext4_create_inline_data() has failed.


[73131.453234] kernel BUG at fs/ext4/inline.c:223!


 212 static void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc,
 213                                    void *buffer, loff_t pos, unsigned int len)
 214 {
<...>
 223         BUG_ON(!EXT4_I(inode)->i_inline_off);
 224         BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);

This patch handles the error and prints out a emergency msg saying potential
data loss for the given inode (since we couldn't restore the original
inline_data due to some previous error).

[ 9571.070313] EXT4-fs (dm-0): error restoring inline_data for inode -- potential data loss! (inode 1703982, error -30)

Reported-by: Eric Whitney 
Signed-off-by: Ritesh Harjani 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/9f4cd7dfd54fa58ff27270881823d94ddf78dd07.1642416995.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org



mm: introduce memalloc_retry_wait()
2022-01-15T14:30:29+00:00

Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying.  Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:

 - a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
 - a need to check for the process being signalled between failures
 - the possibility that other recovery actions could be performed
 - the allocation is quite deep in support code, and passing down an
   extra flag to say if __GFP_NOFAIL is wanted would be clumsy.

Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.

It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.

This patch introduces memalloc_retry_wait() with takes on that
responsibility.  Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used.  It will wait
however is appropriate.

For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests.  If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing.  So there is no need for much
further waiting.  memalloc_retry_wait() will wait until the current
jiffie ends.  If this condition is not met, then alloc_page() won't have
waited much if at all.  In that case memalloc_retry_wait() waits about
200ms.  This is the delay that most current loops uses.

linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.

Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown 
Cc: Dave Chinner 
Cc: Michal Hocko 
Cc: "Theodore Ts'o" 
Cc: Jaegeuk Kim 
Cc: Chao Yu 
Cc: Darrick J. Wong 
Cc: Chuck Lever 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 




ext4: remove extent cache entries when truncating inline data
2021-09-09T14:52:05+00:00

Conditionally remove all cached extents belonging to an inode
when truncating its inline data.  It's only necessary to attempt to
remove cached extents when a conversion from inline to extent storage
has been initiated (!EXT4_STATE_MAY_INLINE_DATA).  This avoids
unnecessary es lock overhead in the more common inline case.

Signed-off-by: Eric Whitney 
Signed-off-by: Theodore Ts'o 
Link: https://lore.kernel.org/r/20210819144927.25163-2-enwlinux@gmail.com
Signed-off-by: Theodore Ts'o 




Merge branch 'delalloc-buffer-write' into dev
2021-09-09T14:47:06+00:00

Fix a bug in how we update i_disksize, and the error path in
inline_data_end.  Finally, drop an unnecessary creation of a journal
handle which was only needed for inline data, which can give us a
large performance gain in delayed allocation writes.

Signed-off-by: Theodore Ts'o 




ext4: factor out write end code of inline file
2021-09-05T03:38:18+00:00

Now that the inline_data file write end procedure are falled into the
common write end functions, it is not clear. Factor them out and do
some cleanup. This patch also drop ext4_da_write_inline_data_end()
and switch to use ext4_write_inline_data_end() instead because we also
need to do the same error processing if we failed to write data into
inline entry.

Signed-off-by: Zhang Yi 
Reviewed-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Link: https://lore.kernel.org/r/20210716122024.1105856-4-yi.zhang@huawei.com




ext4: correct the error path of ext4_write_inline_data_end()
2021-09-05T03:38:18+00:00

Current error path of ext4_write_inline_data_end() is not correct.

Firstly, it should pass out the error value if ext4_get_inode_loc()
return fail, or else it could trigger infinite loop if we inject error
here. And then it's better to add inode to orphan list if it return fail
in ext4_journal_stop(), otherwise we could not restore inline xattr
entry after power failure. Finally, we need to reset the 'ret' value if
ext4_write_inline_data_end() return success in ext4_write_end() and
ext4_journalled_write_end(), otherwise we could not get the error return
value of ext4_journal_stop().

Signed-off-by: Zhang Yi 
Reviewed-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Link: https://lore.kernel.org/r/20210716122024.1105856-3-yi.zhang@huawei.com




ext4: Support for checksumming from journal triggers
2021-08-31T03:36:50+00:00

JBD2 layer support triggers which are called when journaling layer moves
buffer to a certain state. We can use the frozen trigger, which gets
called when buffer data is frozen and about to be written out to the
journal, to compute block checksums for some buffer types (similarly as
does ocfs2). This avoids unnecessary repeated recomputation of the
checksum (at the cost of larger window where memory corruption won't be
caught by checksumming) and is even necessary when there are
unsynchronized updaters of the checksummed data.

So add superblock and journal trigger type arguments to
ext4_journal_get_write_access() and ext4_journal_get_create_access() so
that frozen triggers can be set accordingly. Also add inode argument to
ext4_walk_page_buffers() and all the callbacks used with that function
for the same purpose. This patch is mostly only a change of prototype of
the above mentioned functions and a few small helpers. Real checksumming
will come later.

Reviewed-by: Theodore Ts'o 
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20210816095713.16537-1-jack@suse.cz
Signed-off-by: Theodore Ts'o 




ext4: fix race writing to an inline_data file while its xattrs are changing
2021-08-31T03:36:50+00:00

The location of the system.data extended attribute can change whenever
xattr_sem is not taken.  So we need to recalculate the i_inline_off
field since it mgiht have changed between ext4_write_begin() and
ext4_write_end().

This means that caching i_inline_off is probably not helpful, so in
the long run we should probably get rid of it and shrink the in-memory
ext4 inode slightly, but let's fix the race the simple way for now.

Cc: stable@kernel.org
Fixes: f19d5870cbf72 ("ext4: add normal write support for inline data")
Reported-by: syzbot+13146364637c7363a7de@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o