Revert "ext4: Fix warnings when freezing filesystem with journaled data"

After making ext4_writepages() properly clean all pages there is no need
for special treatment of filesystem freezing. Revert commit
e6c28a26b799c7640b77daff3e4a67808c74381c.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-13-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Update comment in mpage_prepare_extent_to_map()

Since filemap_write_and_wait() is now enough to get journalled data to
final location update the comment in mpage_prepare_extent_to_map().

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-12-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Simplify handling of journalled data in ext4_bmap()

Now that ext4_writepages() gets journalled data into its final location
we just use filemap_write_and_wait() instead of special handling of
journalled data in ext4_bmap(). We can also drop EXT4_STATE_JDATA flag
as it is not used anymore.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-11-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Drop special handling of journalled data from ext4_quota_on()

Now that ext4_writepages() makes sure all journalled data is committed
and checkpointed, sync_filesystem() call done by dquot_quota_on() is
enough for quota IO to see uptodate data. So drop special handling of
journalled data from ext4_quota_on().

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-10-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Drop special handling of journalled data from ext4_evict_inode()

Now that ext4_writepages() makes sure journalled data is on stable
storage, write_inode_now() call in iput_final() is enough to make
pagecache pages with journalled data really clean (data committed and
checkpointed). So we can drop special handling of journalled data in
ext4_evict_inode().

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-9-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Fix special handling of journalled data from extent zeroing

The handling of journalled data in ext4_zero_range() is incomplete. We
do not need to commit running transaction but we rather need to
checkpoint pages with journalled data. If we don't, journal tail can be
advanced beyond transaction containing the journalled data and if we
then crash before committing the transaction doing the zeroing we will
have inconsistent (too old) data in the file. Make sure file pages with
journalled data are properly checkpointed before removing them from the
page cache.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-8-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Drop special handling of journalled data from extent shifting operations

Now that filemap_write_and_wait() makes sure pages with journalled data
are safely on disk, ext4_collapse_range() and ext4_insert_range() do
not need special handling of journalled data.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-7-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Drop special handling of journalled data from ext4_sync_file()

Now that ext4_writepages() make sure all pages with journalled data are
stable on disk, we don't need special handling of journalled data in
ext4_sync_file().

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-6-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Commit transaction before writing back pages in data=journal mode

When journalling data we currently just walk over pages, journal those
that are marked for delayed dirtying (only pinned pages dirtied behing
our back these days) and checkpoint other dirty pages. Because some
pages may be part of running transaction the result is that after
filemap_write_and_wait() we are not guaranteed pages are stable on disk.
Thus places that want to flush current pagecache content need to jump
through hoops to make sure journalled data is not lost. This is
manageable in cases completely controlled by ext4 (such as extent
shifting operations or inode eviction) but it gets ugly for stuff like
fsverity. Furthermore it is rather error prone as people often do not
realize journalled data needs special handling.

So change ext4_writepages() to commit transaction with inode's data
before going through the writeback loop in WB_SYNC_ALL mode. As a result
filemap_write_and_wait() is now really getting pages to stable storage
and makes pagecache pages safe to reclaim. Consequently we can remove
the special handling of journalled data from several places in follow up
patches.

Note that this will make fsync(2) for journalled data more expensive as
we will end up not only committing the transaction we need but also
checkpointing the data (which we may have previously skipped if the data
was part of the running transaction). If we really cared, we would need
to introduce special VFS function for writing out & invalidating page
cache for a range, use ->launder_page callback to perform checkpointing,
and use it from all the places that need this functionality. But at this
point I'm not convinced the complexity is worth it.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-5-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Clear dirty bit from pages without data to write

With journalled data it can happen that checkpointing code will write
out page contents without clearing the page dirty bit. The logic in
ext4_page_nomap_can_writeout() then results in us never calling
mpage_submit_page() and thus clearing the dirty bit. Drop the
optimization with ext4_page_nomap_can_writeout() and just always call to
mpage_submit_page(). ext4_bio_write_page() knows when to redirty the
page and the additional clearing & setting of page dirty bit for ordered
mode writeout is not that expensive to jump through the hoops for it.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-4-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Keep pages with journalled data dirty

Currently we clear page dirty bit when we checkpoint some buffers from a
page with journalled data or when we perform delayed dirtying of a page
in ext4_writepages(). In a quest to simplify handling of journalled data
we want to keep page dirty as long as it has either buffers to
checkpoint or journalled dirty data. So make sure to keep page dirty in
ext4_writepages() if it still has journalled data attached to it.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Mark pages with journalled data dirty

Currently pages with journalled data written by write(2) or modified by
block zeroing during truncate(2) are not marked as dirty. They are
dirtied only once the transaction commits. This however makes writeback
code think inode has no pages to write and so ext4_writepages() is not
called to make pages with journalled data persistent. Mark pages with
journalled data dirty (similarly as it happens for writes through mmap)
so that writeback code knows about them and ext4_writepages() can do
what it needs to to the inode.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

jdb2: Don't refuse invalidation of already invalidated buffers

When invalidating buffers under the partial tail page,
jbd2_journal_invalidate_folio() returns -EBUSY if the buffer is part of
the committing transaction as we cannot safely modify buffer state.
However if the buffer is already invalidated (due to previous
invalidation attempts from ext4_wait_for_tail_page_commit()), there's
nothing to do and there's no point in returning -EBUSY. This fixes
occasional warnings from ext4_journalled_invalidate_folio() triggered by
generic/051 fstest when blocksize < pagesize.

Fixes: 53e872681fed ("ext4: fix deadlock in journal_unmap_buffer()")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230329154950.19720-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Use a folio in ext4_read_merkle_tree_page

This is an implementation of fsverity_operations read_merkle_tree_page,
so it must still return the precise page asked for, but we can use the
folio API to reduce the number of conversions between folios & pages.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-30-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert pagecache_read() to use a folio

Use the folio API and support folios of arbitrary sizes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-29-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert mext_page_mkuptodate() to take a folio

Use a folio throughout.  Does not support large folios due to
an array sized for MAX_BUF_PER_PAGE, but it does remove a few
calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-28-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Use a folio iterator in __read_end_io()

Iterate once per folio, not once per page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-27-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Use a folio in ext4_page_mkwrite()

Convert to the folio API, saving a few calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-26-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_block_write_begin() to take a folio

All the callers now have a folio, so pass that in and operate on folios.
Removes four calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230324180129.1220691-25-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_mpage_readpages() to work on folios

This definitely doesn't include support for large folios; there
are all kinds of assumptions about the number of buffers attached
to a folio.  But it does remove several calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-24-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Use a folio in ext4_da_write_begin()

Remove a few calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-23-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_page_nomap_can_writeout to ext4_folio_nomap_can_writeout

Its one caller already uses a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-22-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert __ext4_block_zero_page_range() to use a folio

Use folio APIs throughout.  Saves many calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230324180129.1220691-21-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_journalled_zero_new_buffers() to use a folio

Remove a call to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-20-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Use a folio in ext4_journalled_write_end()

Convert the incoming page to a folio to remove a few calls to
compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-19-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_write_end() to use a folio

Convert the incoming struct page to a folio.  Replaces two implicit
calls to compound_head() with one explicit call.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-18-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_write_begin() to use a folio

Remove a lot of calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-17-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_write_inline_data_end() to use a folio

Convert the incoming page to a folio so that we call compound_head()
only once instead of seven times.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-16-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_read_inline_page() to ext4_read_inline_folio()

All callers now have a folio, so pass it and use it.  The folio may
be large, although I doubt we'll want to use a large folio for an
inline file.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-15-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_da_write_inline_data_begin() to use a folio

Saves a number of calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-14-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_da_convert_inline_data_to_extent() to use a folio

Saves a number of calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-13-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_try_to_write_inline_data() to use a folio

Saves a number of calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-12-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_convert_inline_data_to_extent() to use a folio

Saves a number of calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-11-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_readpage_inline() to take a folio

Use the folio API in this function, saves a few calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-10-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_bio_write_page() to ext4_bio_write_folio()

The only caller now has a folio so pass it in directly and avoid the call
to page_folio() at the beginning.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-9-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert mpage_page_done() to mpage_folio_done()

All callers now have a folio so we can pass one in and use the folio
APIs to support large folios as well as save instructions by eliminating
a call to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-8-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert mpage_submit_page() to mpage_submit_folio()

All callers now have a folio so we can pass one in and use the folio
APIs to support large folios as well as save instructions by eliminating
calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-7-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Turn mpage_process_page() into mpage_process_folio()

The page/folio is only used to extract the buffers, so this is a
simple change.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-6-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_finish_bio() to use folios

Prepare ext4 to support large folios in the page writeback path.
Also set the actual error in the mapping, not just -EIO.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-5-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert ext4_bio_write_page() to use a folio

Remove several calls to compound_head() and the last caller of
set_page_writeback_keepwrite(), so remove the wrapper too.

Also export bio_add_folio() as this is the first caller from a module.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230324180129.1220691-4-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fscrypt: Add some folio helper functions

fscrypt_is_bounce_folio() is the equivalent of fscrypt_is_bounce_page()
and fscrypt_pagecache_folio() is the equivalent of fscrypt_pagecache_page().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230324180129.1220691-3-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs: Add FGP_WRITEBEGIN

This particular combination of flags is used by most filesystems
in their ->write_begin method, although it does find use in a
few other places.  Before folios, it warranted its own function
(grab_cache_page_write_begin()), but I think that just having specialised
flags is enough.  It certainly helps the few places that have been
converted from grab_cache_page_write_begin() to __filemap_get_folio().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-2-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Remove the logic to trim inode PAs

Earlier, inode PAs were stored in a linked list. This caused a need to
periodically trim the list down inorder to avoid growing it to a very
large size, as this would severly affect performance during list
iteration.

Recent patches changed this list to an rbtree, and since the tree scales
up much better, we no longer need to have the trim functionality, hence
remove it.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/c409addceaa3ade4b40328e28e3b54b2f259689e.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Use rbtrees to manage PAs instead of inode i_prealloc_list

Currently, the kernel uses i_prealloc_list to hold all the inode
preallocations. This is known to cause degradation in performance in
workloads which perform large number of sparse writes on a single file.
This is mainly because functions like ext4_mb_normalize_request() and
ext4_mb_use_preallocated() iterate over this complete list, resulting in
slowdowns when large number of PAs are present.

Patch 27bc446e2 partially fixed this by enforcing a limit of 512 for
the inode preallocation list and adding logic to continually trim the
list if it grows above the threshold, however our testing revealed that
a hardcoded value is not suitable for all kinds of workloads.

To optimize this, add an rbtree to the inode and hold the inode
preallocations in this rbtree. This will make iterating over inode PAs
faster and scale much better than a linked list. Additionally, we also
had to remove the LRU logic that was added during trimming of the list
(in ext4_mb_release_context()) as it will add extra overhead in rbtree.
The discards now happen in the lowest-logical-offset-first order.

** Locking notes **

With the introduction of rbtree to maintain inode PAs, we can't use RCU
to walk the tree for searching since it can result in partial traversals
which might miss some nodes(or entire subtrees) while discards happen
in parallel (which happens under a lock).  Hence this patch converts the
ei->i_prealloc_lock spin_lock to rw_lock.

Almost all the codepaths that read/modify the PA rbtrees are protected
by the higher level inode->i_data_sem (except
ext4_mb_discard_group_preallocations() and ext4_clear_inode()) IIUC, the
only place we need lock protection is when one thread is reading
"searching" the PA rbtree (earlier protected under rcu_read_lock()) and
another is "deleting" the PAs in ext4_mb_discard_group_preallocations()
function (which iterates all the PAs using the grp->bb_prealloc_list and
deletes PAs from the tree without taking any inode lock (i_data_sem)).

So, this patch converts all rcu_read_lock/unlock() paths for inode list
PA to use read_lock() and all places where we were using
ei->i_prealloc_lock spinlock will now be using write_lock().

Note that this makes the fast path (searching of the right PA e.g.
ext4_mb_use_preallocated() or ext4_mb_normalize_request()), now use
read_lock() instead of rcu_read_lock/unlock().  Ths also will now block
due to slow discard path (ext4_mb_discard_group_preallocations()) which
uses write_lock().

But this is not as bad as it looks. This is because -

1. The slow path only occurs when the normal allocation failed and we
   can say that we are low on disk space.  One can argue this scenario
   won't be much frequent.

2. ext4_mb_discard_group_preallocations(), locks and unlocks the rwlock
   for deleting every individual PA.  This gives enough opportunity for
   the fast path to acquire the read_lock for searching the PA inode
   list.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/4137bce8f6948fedd8bae134dabae24acfe699c6.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert pa->pa_inode_list and pa->pa_obj_lock into a union

** Splitting pa->pa_inode_list **

Currently, we use the same pa->pa_inode_list to add a pa to either
the inode preallocation list or the locality group preallocation list.
For better clarity, split this list into a union of 2 list_heads and use
either of the them based on the type of pa.

** Splitting pa->pa_obj_lock **

Currently, pa->pa_obj_lock is either assigned &ei->i_prealloc_lock for
inode PAs or lg_prealloc_lock for lg PAs, and is then used to lock the
lists containing these PAs. Make the distinction between the 2 PA types
clear by changing this lock to a union of 2 locks. Explicitly use the
pa_lock_node.inode_lock for inode PAs and pa_lock_node.lg_lock for lg
PAs.

This patch is required so that the locality group preallocation code
remains the same as in upcoming patches we are going to make changes to
inode preallocation code to move from list to rbtree based
implementation. This patch also makes it easier to review the upcoming
patches.

There are no functional changes in this patch.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1d7ac0557e998c3fc7eef422b52e4bc67bdef2b0.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()

When the length of best extent found is less than the length of goal extent
we need to make sure that the best extent atleast covers the start of the
original request. This is done by adjusting the ac_b_ex.fe_logical (logical
start) of the extent.

While doing so, the current logic sometimes results in the best extent's
logical range overflowing the goal extent. Since this best extent is later
added to the inode preallocation list, we have a possibility of introducing
overlapping preallocations. This is discussed in detail here [1].

As per Jan's suggestion, to fix this, replace the existing logic with the
below logic for adjusting best extent as it keeps fragmentation in check
while ensuring logical range of best extent doesn't overflow out of goal
extent:

1. Check if best extent can be kept at end of goal range and still cover
   original start.
2. Else, check if best extent can be kept at start of goal range and still
   cover original start.
3. Else, keep the best extent at start of original request.

Also, add a few extra BUG_ONs that might help catch errors faster.

[1] https://lore.kernel.org/r/Y+OGkVvzPN0RMv0O@li-bb2b2a4c-3307-11b2-a85c-8fa5c3a69313.ibm.com

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/f96aca6d415b36d1f90db86c1a8cd7e2e9d7ab0e.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Abstract out overlap fix/check logic in ext4_mb_normalize_request()

Abstract out the logic of fixing PA overlaps in ext4_mb_normalize_request
to improve readability of code. This also makes it easier to make changes
to the overlap logic in future.

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/9b35f3955a1d7b66bbd713eca1e63026e01f78c1.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Move overlap assert logic into a separate function

Abstract out the logic to double check for overlaps in normalize_pa to
a separate function. Since there has been no reports in past where we
have seen any overlaps which hits this bug_on(), in future we can
consider calling this function under "#ifdef AGGRESSIVE_CHECK" only.

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/35dd5d94fa0b2d1cd2d2947adf8967279c72967d.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Refactor code in ext4_mb_normalize_request() and ext4_mb_use_preallocated()

Change some variable names to be more consistent and
refactor some of the code to make it easier to read.

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/8edcab489c06cf861b19d87207d9b0ff7ac7f3c1.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Refactor code related to freeing PAs

This patch makes the following changes:

*  Rename ext4_mb_pa_free to ext4_mb_pa_put_free
   to better reflect its purpose

*  Add new ext4_mb_pa_free() which only handles freeing

*  Refactor ext4_mb_pa_callback() to use ext4_mb_pa_free()

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/b273bc9cbf5bd278f641fa5bc6c0cc9e6cb3330c.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Stop searching if PA doesn't satisfy non-extent file

If we come across a PA that matches the logical offset but is unable to
satisfy a non-extent file due to its physical start being higher than
that supported by non extent files, then simply stop searching for
another PA and break out of loop. This is because, since PAs don't
overlap, we won't be able to find another inode PA which can satisfy the
original request.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/42404ca29bd304ae2c962184c3c32a02e8eefcd0.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: convert some BUG_ON's in mballoc to use WARN_RATELIMITED instead

In cases where we have an obvious way of continuing, let's use
WARN_RATELIMITED() instead of BUG_ON().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: avoid unnecessary pointer dereference in ext4_mb_normalize_request

Result of EXT4_SB(ac->ac_sb) is already stored in sbi at beginning of
ext4_mb_normalize_request. Use sbi instead of EXT4_SB(ac->ac_sb) to
remove unnecessary pointer dereference.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230311170949.1047958-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: fix typos in mballoc

pa_plen -> pa_len
pa_start -> pa_pstart

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230311170949.1047958-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: simplify calculation of blkoff in ext4_mb_new_blocks_simple

We try to allocate a block from goal in ext4_mb_new_blocks_simple. We
only need get blkoff in first group with goal and set blkoff to 0 for
the rest groups.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-21-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove comment code ext4_discard_preallocations

Just remove comment code in ext4_discard_preallocations.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-20-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove repeat assignment to ac_f_ex

Call trace to assign ac_f_ex:
ext4_mb_use_best_found
ac->ac_f_ex = ac->ac_b_ex;
ext4_mb_new_preallocation
ext4_mb_new_group_pa
ac->ac_f_ex = ac->ac_b_ex;
ext4_mb_new_inode_pa
ac->ac_f_ex = ac->ac_b_ex;

Actually allocated blocks is already stored in ac_f_ex in
ext4_mb_use_best_found, so there is no need to assign ac_f_ex
in ext4_mb_new_group_pa and ext4_mb_new_inode_pa.
Just remove repeat assignment to ac_f_ex in ext4_mb_new_group_pa
and ext4_mb_new_inode_pa.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-19-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unnecessary goto in ext4_mb_mark_diskspace_used

When ext4_read_block_bitmap fails, we can return PTR_ERR(bitmap_bh) to
remove unnecessary NULL check of bitmap_bh.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-18-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unnecessary count2 in ext4_free_data_in_buddy

count2 is always 1 in mb_debug, just remove unnecessary count2.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-17-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unnecessary exit_meta_group_info tag

We goto exit_meta_group_info only to return -ENOMEM. Return -ENOMEM
directly instead of goto to remove this unnecessary tag.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-16-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: use best found when complex scan of group finishs

If any bex which meets bex->fe_len >= gex->fe_len is found, then it will
always be used when complex scan of group that bex belongs to finishs.
So there will not be any lock-unlock period.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-15-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits

Only call trace of ext4_mb_check_limits is as following:
ext4_mb_complex_scan_group
ext4_mb_measure_extent
ext4_mb_check_limits(ac, e4b, 0);
ext4_mb_check_limits(ac, e4b, 1);

If the first ac->ac_found > sbi->s_mb_max_to_scan check in
ext4_mb_check_limits is met, we will set ac_status to
AC_STATUS_BREAK and call ext4_mb_try_best_found to try to use
ac->ac_b_ex.
If ext4_mb_try_best_found successes, then block allocation finishs,
the removed ac->ac_found > sbi->s_mb_min_to_scan check is not reachable.
If ext4_mb_try_best_found fails, then we set EXT4_MB_HINT_FIRST and
reset ac->ac_b_ex to retry block allocation. We will use any found
free extent in ext4_mb_measure_extent before reach the removed
ac->ac_found > sbi->s_mb_min_to_scan check.
In summary, the removed ac->ac_found > sbi->s_mb_min_to_scan check is
not reachable and we can remove that dead check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-14-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove dead check in mb_buddy_mark_free

We always adjust first to even number and adjust last to odd number, so
first == last will never happen. Remove this dead check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-13-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unnecessary check in ext4_mb_new_blocks

1. remove unnecessary ac check:
We always go to out tag before ac is successfully allocated, then we can
move out tag after free of ac and remove NULL check of ac.

2. remove unnecessary *errp check:
We always go to errout tag if *errp is non-zero, then we can move errout
tag into error handle if *errp is non-zero.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-12-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unnecessary e4b->bd_buddy_page check in ext4_mb_load_buddy_gfp

e4b->bd_buddy_page is only set if we initialize ext4_buddy successfully. So
e4b->bd_buddy_page is always NULL in error handle branch. Just remove the
dead check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-11-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Remove unnecessary release when memory allocation failed in ext4_mb_init_cache

If we alloc array of buffer_head failed, there is no resource need to be
freed and we can simpily return error.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-10-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unused return value of ext4_mb_try_best_found and ext4_mb_free_metadata

Return value static function ext4_mb_try_best_found and
ext4_mb_free_metadata is not used. Just remove unused return value.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-9-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: add missed brelse in ext4_free_blocks_simple

Release bitmap buffer_head we got if error occurs.
Besides, this patch remove unused assignment to err.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-8-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: protect pa->pa_free in ext4_discard_allocated_blocks

If ext4_mb_mark_diskspace_used fails in ext4_mb_new_blocks, we may
discard pa already in list. Protect pa with pa_lock to avoid race.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-7-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: correct start of used group pa for debug in ext4_mb_use_group_pa

As we don't correct pa_lstart here, so there is no need to subtract
pa_lstart with consumed len.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-6-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: correct calculation of s_mb_preallocated

We will add pa_free to s_mb_preallocated when new ext4_prealloc_space is
created. In ext4_mb_new_inode_pa, we will call ext4_mb_use_inode_pa
before adding pa_free to s_mb_preallocated. However, ext4_mb_use_inode_pa
will consume pa_free for block allocation which triggerred the creation
of ext4_prealloc_space. Add pa_free to s_mb_preallocated before
ext4_mb_use_inode_pa to correct calculation of s_mb_preallocated.
There is no such problem in ext4_mb_new_group_pa as pa_free of group pa
is consumed in ext4_mb_release_context instead of ext4_mb_use_group_pa.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: get correct ext4_group_info in ext4_mb_prefetch_fini

We always get ext4_group_desc with group + 1 and ext4_group_info with
group to check if we need do initialize ext4_group_info for the group.
Just get ext4_group_desc with group for ext4_group_info initialization
check.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: allow to find by goal if EXT4_MB_HINT_GOAL_ONLY is set

If EXT4_MB_HINT_GOAL_ONLY is set, ext4_mb_regular_allocator will only
allocate blocks from ext4_mb_find_by_goal. Allow to find by goal in
ext4_mb_find_by_goal if EXT4_MB_HINT_GOAL_ONLY is set or allocation
with EXT4_MB_HINT_GOAL_ONLY set will always fail.

EXT4_MB_HINT_GOAL_ONLY is not used at all, so the problem is not
found for now.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: set goal start correctly in ext4_mb_normalize_request

We need to set ac_g_ex to notify the goal start used in
ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in
ext4_mb_normalize_request.
Besides we should assure goal start is in range [first_data_block,
blocks_count) as ext4_mb_initialize_context does.

[ Added a check to make sure size is less than ar->pright; otherwise
  we could end up passing an underflowed value of ar->pright - size to
  ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on.
  - TYT ]

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unused group parameter in ext4_block_bitmap_csum_set

Remove unused group parameter in ext4_block_bitmap_csum_set. After this,
group parameter in ext4_set_bitmap_checksums is also not used, just
remove it too.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230221203027.2359920-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unused group parameter in ext4_block_bitmap_csum_verify

Remove unused group parameter in ext4_block_bitmap_csum_verify.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230221203027.2359920-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unused group parameter in ext4_inode_bitmap_csum_set

Remove unused group parameter in ext4_inode_bitmap_csum_set.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230221203027.2359920-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unused group parameter in ext4_inode_bitmap_csum_verify

Remove unused group parameter in ext4_inode_bitmap_csum_verify.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230221203027.2359920-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: improve inode table blocks counting in ext4_num_overhead_clusters

As inode table blocks are contiguous, inode table blocks inside the
block_group can be represented as range [itbl_cluster_start,
itbl_cluster_last]. Then we can simply account inode table cluters and
check cluster overlap with [itbl_cluster_start, itbl_cluster_last]
instead of traverse each block of inode table.

By the way, this patch fixes code style problem of comment for
ext4_num_overhead_clusters.

[ Merged fix-up patch which fixed potentially access to an
  uninitialzied stack variable. --TYT ]

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-8-shikemeng@huaweicloud.com
Link: https://lore.kernel.org/r/202303171446.eLEhZzAu-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: stop trying to verify just initialized bitmap in ext4_read_block_bitmap_nowait

For case we initialize a bitmap bh, we will set bitmap bh verified.
We can return immediately instead of goto verify to remove unnecessary
work for trying to verify bitmap bh.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-7-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove stale comment in ext4_init_block_bitmap

Commit bdfb6ff4a255d ("ext4: mark group corrupt on group descriptor
checksum") added flag to indicate corruption of group instead of
marking all blocks used. Just remove stale comment.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-6-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: remove unnecessary check in ext4_bg_num_gdb_nometa

We only call ext4_bg_num_gdb_nometa if there is no meta_bg feature or group
does not reach first_meta_bg, so group must not reside in meta group. Then
group has a global gdt if superblock exists. Just remove confusing branch
that meta_bg feature exists.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: call ext4_bg_num_gdb_[no]meta directly in ext4_num_base_meta_clusters

ext4_num_base_meta_clusters is already aware of meta_bg feature and test
if block_group is inside real meta block groups before calling
ext4_bg_num_gdb. Then ext4_bg_num_gdb will check if block group is inside
a real meta block groups again to decide either ext4_bg_num_gdb_meta or
ext4_bg_num_gdb_nometa is needed.
Call ext4_bg_num_gdb_meta or ext4_bg_num_gdb_nometa directly after we
check if block_group is inside a meta block groups in
ext4_num_base_meta_clusters to remove redundant check of meta block
groups in ext4_bg_num_gdb.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: correct validation check of inode table in ext4_valid_block_bitmap

1.Last valid cluster of inode table is EXT4_B2C(sbi, offset +
sbi->s_itb_per_group - 1). We should make sure last valid cluster is <
max_bit, i.e., EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) is <
max_bit rather than EXT4_B2C(sbi, offset + sbi->s_itb_per_group) is
< max_bit.

2.Bit search length should be last valid cluster plus 1, i.e.,
EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) + 1 rather than
EXT4_B2C(sbi, offset + sbi->s_itb_per_group).

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: properly handle error of ext4_init_block_bitmap in ext4_read_block_bitmap_nowait

We mark buffer_head of bitmap successfully initialized even error occurs
in ext4_init_block_bitmap. Although we will return error, we will get a
invalid buffer_head of bitmap from next ext4_read_block_bitmap_nowait
which is marked buffer_verified but not successfully initialized actually
in previous ext4_read_block_bitmap_nowait.
Fix this by only marking buffer_head successfully initialized if
ext4_init_block_bitmap successes.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: fix comment: "start start" -> "start" in mpage_prepare_extent_to_map()

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Fix warnings when freezing filesystem with journaled data

Test generic/390 in data=journal mode often triggers a warning that
ext4_do_writepages() tries to start a transaction on frozen filesystem.
This happens because although all dirty data is properly written, jbd2
checkpointing code writes data through submit_bh() and as a result only
buffer dirty bits are cleared but page dirty bits stay set. Later when
the filesystem is frozen, writeback code comes, tries to write
supposedly dirty pages and the warning triggers. Fix the problem by
calling sync_filesystem() once more after flushing the whole journal to
clear stray page dirty bits.

[ Applied fixup patches to address crashes when running data=journal
  tests; see links for more details -- TYT ]

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230308142528.12384-1-jack@suse.cz
Reported-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/all/20230319183617.GA896@sol.localdomain
Link: https://lore.kernel.org/r/20230323145404.21381-1-jack@suse.cz
Link: https://lore.kernel.org/r/20230323145404.21381-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: Convert data=journal writeback to use ext4_writepages()

Add support for writeback of journalled data directly into
ext4_writepages() instead of offloading it to write_cache_pages(). This
actually significantly simplifies the code and reduces code duplication.
For checkpointing of committed data we can use ext4_writepages()
rightaway the same way as writeback of ordered data uses it on
transaction commit. For journalling of dirty mapped pages, we need to
add a special case to mpage_prepare_extent_to_map() to add all page
buffers to the journal.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-8-tytso@mit.edu

ext4: Move mpage_page_done() calls after error handling

In case mpage_submit_page() returns error, it doesn't really matter
whether we call mpage_page_done() and then return error or whether we
return directly because in that case page cleanup will be done by
mpage_release_unused_pages() instead. Logically, it makes more sense to
leave the cleanup to mpage_release_unused_pages() because we didn't
succeed in writing the page. So move mpage_page_done() calls after the
error handling.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-7-tytso@mit.edu

ext4: Move page unlocking out of mpage_submit_page()

Move page unlocking during page writeback out of mpage_submit_page()
into the callers. This will allow writeback in data=journal mode to keep
the page locked for a bit longer. Since page unlocking it tightly
connected to increment of mpd->first_page (as that determines cleanup of
locked but unwritten pages), move page unlocking as well as
mpd->first_page handling into a helper function.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-6-tytso@mit.edu

ext4: Don't unlock page in ext4_bio_write_page()

Do not unlock the written page in ext4_bio_write_page(). Instead leave
the page locked and unlock it in the callers. We'll need to keep the
page locked for data=journal writeback for a bit longer.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-5-tytso@mit.edu

ext4: Mark page for delayed dirtying only if it is pinned

In data=journal mode, page should be dirtied only when it has buffers
for checkpoint or it is writeably mapped. In the first case, we don't
need to do anything special. In the second case, page was already added
to the journal by ext4_page_mkwrite() and since transaction commit
writeprotects mapped pages again, page should be writeable (and thus
dirtied) only while it is part of the running transaction. So nothing
needs to be done either. The only special case is when someone pins the
page and uses this pin for modifying page data. So recognize this
special case and only then mark the page as having data that needs
adding to the journal.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-4-tytso@mit.edu

ext4: Use nr_to_write directly in mpage_prepare_extent_to_map()

When looking up extent of pages to map in mpage_prepare_extent_to_map()
we count how many pages we still need to find in a copy of
wbc->nr_to_write counter. With more complex page handling for
data=journal mode, it will be easier to use wbc->nr_to_write directly so
that we don't forget to carry over changes back to nr_to_write counter.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-3-tytso@mit.edu

ext4: Update stale comment about write constraints

The comment above do_journal_get_write_access() is very stale. Most of
it just does not refer to what the function does today or how jbd2
works. The bit about transaction handling during write(2) is still
correct so just update the function names in that part and move the
comment to a more appropriate place.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230228051319.4085470-2-tytso@mit.edu

Linux 6.3-rc3

Merge tag 'trace-v6.3-rc2' of git://git./linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix setting affinity of hwlat threads in containers

   Using sched_set_affinity() has unwanted side effects when being
   called within a container. Use set_cpus_allowed_ptr() instead

 - Fix per cpu thread management of the hwlat tracer:
    - Do not start per_cpu threads if one is already running for the CPU
    - When starting per_cpu threads, do not clear the kthread variable
      as it may already be set to running per cpu threads

 - Fix return value for test_gen_kprobe_cmd()

   On error the return value was overwritten by being set to the result
   of the call from kprobe_event_delete(), which would likely succeed,
   and thus have the function return success

 - Fix splice() reads from the trace file that was broken by commit
   36e2c7421f02 ("fs: don't allow splice read/write without explicit
   ops")

 - Remove obsolete and confusing comment in ring_buffer.c

   The original design of the ring buffer used struct page flags for
   tricks to optimize, which was shortly removed due to them being
   tricks. But a comment for those tricks remained

 - Set local functions and variables to static

* tag 'trace-v6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptr
  ring-buffer: remove obsolete comment for free_buffer_page()
  tracing: Make splice_read available again
  ftrace: Set direct_ops storage-class-specifier to static
  trace/hwlat: Do not start per-cpu thread if it is already running
  trace/hwlat: Do not wipe the contents of per-cpu thread data
  tracing/osnoise: set several trace_osnoise.c variables storage-class-specifier to static
  tracing: Fix wrong return in kprobe_event_gen_test.c

tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptr

There is a problem with the behavior of hwlat in a container,
resulting in incorrect output. A warning message is generated:
"cpumask changed while in round-robin mode, switching to mode none",
and the tracing_cpumask is ignored. This issue arises because
the kernel thread, hwlatd, is not a part of the container, and
the function sched_setaffinity is unable to locate it using its PID.
Additionally, the task_struct of hwlatd is already known.
Ultimately, the function set_cpus_allowed_ptr achieves
the same outcome as sched_setaffinity, but employs task_struct
instead of PID.

Test case:

  # cd /sys/kernel/tracing
  # echo 0 > tracing_on
  # echo round-robin > hwlat_detector/mode
  # echo hwlat > current_tracer
  # unshare --fork --pid bash -c 'echo 1 > tracing_on'
  # dmesg -c

Actual behavior:

[573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none

Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 0330f7aa8ee63 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

ring-buffer: remove obsolete comment for free_buffer_page()

The comment refers to mm/slob.c which is being removed. It comes from
commit ed56829cb319 ("ring_buffer: reset buffer page when freeing") and
according to Steven the borrowed code was a page mapcount and mapping
reset, which was later removed by commit e4c2ce82ca27 ("ring_buffer:
allocate buffer page pointer"). Thus the comment is not accurate anyway,
remove it.

Link: https://lore.kernel.org/linux-trace-kernel/20230315142446.27040-1-vbabka@suse.cz
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Reported-by: Mike Rapoport <mike.rapoport@gmail.com>
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fixes: e4c2ce82ca27 ("ring_buffer: allocate buffer page pointer")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tracing: Make splice_read available again

Since the commit 36e2c7421f02 ("fs: don't allow splice read/write
without explicit ops") is applied to the kernel, splice() and
sendfile() calls on the trace file (/sys/kernel/debug/tracing
/trace) return EINVAL.

This patch restores these system calls by initializing splice_read
in file_operations of the trace file. This patch only enables such
functionalities for the read case.

Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com
Cc: stable@vger.kernel.org
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Merge tag 'tty-6.3-rc3' of git://git./linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 6.3-rc3 to resolve
  some reported issues.

  They include:

   - 8250 driver Kconfig issue pointed out by you that showed up in -rc1

   - qcom-geni serial driver fixes

   - various 8250 driver fixes for reported problems

   - fsl_lpuart driver fixes

   - serdev fix for regression in -rc1

   - vt.c bugfix

  All have been in linux-next for over a week with no reported problems"

* tag 'tty-6.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: vt: protect KD_FONT_OP_GET_TALL from unbound access
  serial: qcom-geni: drop bogus uart_write_wakeup()
  serial: qcom-geni: fix mapping of empty DMA buffer
  serial: qcom-geni: fix DMA mapping leak on shutdown
  serial: qcom-geni: fix console shutdown hang
  serdev: Set fwnode for serdev devices
  tty: serial: fsl_lpuart: fix race on RX DMA shutdown
  serial: 8250_pci1xxxx: Disable SERIAL_8250_PCI1XXXX config by default
  serial: 8250_fsl: fix handle_irq locking
  serial: 8250_em: Fix UART port type
  serial: 8250: ASPEED_VUART: select REGMAP instead of depending on it
  tty: serial: fsl_lpuart: skip waiting for transmission complete when UARTCTRL_SBK is asserted
  Revert "tty: serial: fsl_lpuart: adjust SERIAL_FSL_LPUART_CONSOLE config dependency"