<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/fs/jbd2, branch v5.18</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4</title>
<updated>2022-04-23T01:18:27+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-04-23T01:18:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c00c5e1d157bec0ef0b0b59aa5482eb8dc7e8e49'/>
<id>c00c5e1d157bec0ef0b0b59aa5482eb8dc7e8e49</id>
<content type='text'>
Pull ext4 fixes from Ted Ts'o:
 "Fix some syzbot-detected bugs, as well as other bugs found by I/O
  injection testing.

  Change ext4's fallocate to consistently drop set[ug]id bits when an
  fallocate operation might possibly change the user-visible contents of
  a file.

  Also, improve handling of potentially invalid values in the the
  s_overhead_cluster superblock field to avoid ext4 returning a negative
  number of free blocks"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: fix a potential race while discarding reserved buffers after an abort
  ext4: update the cached overhead value in the superblock
  ext4: force overhead calculation if the s_overhead_cluster makes no sense
  ext4: fix overhead calculation to account for the reserved gdt blocks
  ext4, doc: fix incorrect h_reserved size
  ext4: limit length to bitmap_maxbytes - blocksize in punch_hole
  ext4: fix use-after-free in ext4_search_dir
  ext4: fix bug_on in start_this_handle during umount filesystem
  ext4: fix symlink file size not match to file content
  ext4: fix fallocate to use file_modified to update permissions consistently
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ext4 fixes from Ted Ts'o:
 "Fix some syzbot-detected bugs, as well as other bugs found by I/O
  injection testing.

  Change ext4's fallocate to consistently drop set[ug]id bits when an
  fallocate operation might possibly change the user-visible contents of
  a file.

  Also, improve handling of potentially invalid values in the the
  s_overhead_cluster superblock field to avoid ext4 returning a negative
  number of free blocks"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: fix a potential race while discarding reserved buffers after an abort
  ext4: update the cached overhead value in the superblock
  ext4: force overhead calculation if the s_overhead_cluster makes no sense
  ext4: fix overhead calculation to account for the reserved gdt blocks
  ext4, doc: fix incorrect h_reserved size
  ext4: limit length to bitmap_maxbytes - blocksize in punch_hole
  ext4: fix use-after-free in ext4_search_dir
  ext4: fix bug_on in start_this_handle during umount filesystem
  ext4: fix symlink file size not match to file content
  ext4: fix fallocate to use file_modified to update permissions consistently
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd2: fix a potential race while discarding reserved buffers after an abort</title>
<updated>2022-04-21T18:21:30+00:00</updated>
<author>
<name>Ye Bin</name>
<email>yebin10@huawei.com</email>
</author>
<published>2022-03-17T14:21:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=23e3d7f7061f8682c751c46512718f47580ad8f0'/>
<id>23e3d7f7061f8682c751c46512718f47580ad8f0</id>
<content type='text'>
we got issue as follows:
[   72.796117] EXT4-fs error (device sda): ext4_journal_check_start:83: comm fallocate: Detected aborted journal
[   72.826847] EXT4-fs (sda): Remounting filesystem read-only
fallocate: fallocate failed: Read-only file system
[   74.791830] jbd2_journal_commit_transaction: jh=0xffff9cfefe725d90 bh=0x0000000000000000 end delay
[   74.793597] ------------[ cut here ]------------
[   74.794203] kernel BUG at fs/jbd2/transaction.c:2063!
[   74.794886] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[   74.795533] CPU: 4 PID: 2260 Comm: jbd2/sda-8 Not tainted 5.17.0-rc8-next-20220315-dirty #150
[   74.798327] RIP: 0010:__jbd2_journal_unfile_buffer+0x3e/0x60
[   74.801971] RSP: 0018:ffffa828c24a3cb8 EFLAGS: 00010202
[   74.802694] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   74.803601] RDX: 0000000000000001 RSI: ffff9cfefe725d90 RDI: ffff9cfefe725d90
[   74.804554] RBP: ffff9cfefe725d90 R08: 0000000000000000 R09: ffffa828c24a3b20
[   74.805471] R10: 0000000000000001 R11: 0000000000000001 R12: ffff9cfefe725d90
[   74.806385] R13: ffff9cfefe725d98 R14: 0000000000000000 R15: ffff9cfe833a4d00
[   74.807301] FS:  0000000000000000(0000) GS:ffff9d01afb00000(0000) knlGS:0000000000000000
[   74.808338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   74.809084] CR2: 00007f2b81bf4000 CR3: 0000000100056000 CR4: 00000000000006e0
[   74.810047] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   74.810981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   74.811897] Call Trace:
[   74.812241]  &lt;TASK&gt;
[   74.812566]  __jbd2_journal_refile_buffer+0x12f/0x180
[   74.813246]  jbd2_journal_refile_buffer+0x4c/0xa0
[   74.813869]  jbd2_journal_commit_transaction.cold+0xa1/0x148
[   74.817550]  kjournald2+0xf8/0x3e0
[   74.819056]  kthread+0x153/0x1c0
[   74.819963]  ret_from_fork+0x22/0x30

Above issue may happen as follows:
        write                   truncate                   kjournald2
generic_perform_write
 ext4_write_begin
  ext4_walk_page_buffers
   do_journal_get_write_access -&gt;add BJ_Reserved list
 ext4_journalled_write_end
  ext4_walk_page_buffers
   write_end_fn
    ext4_handle_dirty_metadata
                ***************JBD2 ABORT**************
     jbd2_journal_dirty_metadata
 -&gt; return -EROFS, jh in reserved_list
                                                   jbd2_journal_commit_transaction
                                                    while (commit_transaction-&gt;t_reserved_list)
                                                      jh = commit_transaction-&gt;t_reserved_list;
                        truncate_pagecache_range
                         do_invalidatepage
			  ext4_journalled_invalidatepage
			   jbd2_journal_invalidatepage
			    journal_unmap_buffer
			     __dispose_buffer
			      __jbd2_journal_unfile_buffer
			       jbd2_journal_put_journal_head -&gt;put last ref_count
			        __journal_remove_journal_head
				 bh-&gt;b_private = NULL;
				 jh-&gt;b_bh = NULL;
				                      jbd2_journal_refile_buffer(journal, jh);
							bh = jh2bh(jh);
							-&gt;bh is NULL, later will trigger null-ptr-deref
				 journal_free_journal_head(jh);

After commit 96f1e0974575, we no longer hold the j_state_lock while
iterating over the list of reserved handles in
jbd2_journal_commit_transaction().  This potentially allows the
journal_head to be freed by journal_unmap_buffer while the commit
codepath is also trying to free the BJ_Reserved buffers.  Keeping
j_state_lock held while trying extends hold time of the lock
minimally, and solves this issue.

Fixes: 96f1e0974575("jbd2: avoid long hold times of j_state_lock while committing a transaction")
Signed-off-by: Ye Bin &lt;yebin10@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20220317142137.1821590-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
we got issue as follows:
[   72.796117] EXT4-fs error (device sda): ext4_journal_check_start:83: comm fallocate: Detected aborted journal
[   72.826847] EXT4-fs (sda): Remounting filesystem read-only
fallocate: fallocate failed: Read-only file system
[   74.791830] jbd2_journal_commit_transaction: jh=0xffff9cfefe725d90 bh=0x0000000000000000 end delay
[   74.793597] ------------[ cut here ]------------
[   74.794203] kernel BUG at fs/jbd2/transaction.c:2063!
[   74.794886] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[   74.795533] CPU: 4 PID: 2260 Comm: jbd2/sda-8 Not tainted 5.17.0-rc8-next-20220315-dirty #150
[   74.798327] RIP: 0010:__jbd2_journal_unfile_buffer+0x3e/0x60
[   74.801971] RSP: 0018:ffffa828c24a3cb8 EFLAGS: 00010202
[   74.802694] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   74.803601] RDX: 0000000000000001 RSI: ffff9cfefe725d90 RDI: ffff9cfefe725d90
[   74.804554] RBP: ffff9cfefe725d90 R08: 0000000000000000 R09: ffffa828c24a3b20
[   74.805471] R10: 0000000000000001 R11: 0000000000000001 R12: ffff9cfefe725d90
[   74.806385] R13: ffff9cfefe725d98 R14: 0000000000000000 R15: ffff9cfe833a4d00
[   74.807301] FS:  0000000000000000(0000) GS:ffff9d01afb00000(0000) knlGS:0000000000000000
[   74.808338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   74.809084] CR2: 00007f2b81bf4000 CR3: 0000000100056000 CR4: 00000000000006e0
[   74.810047] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   74.810981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   74.811897] Call Trace:
[   74.812241]  &lt;TASK&gt;
[   74.812566]  __jbd2_journal_refile_buffer+0x12f/0x180
[   74.813246]  jbd2_journal_refile_buffer+0x4c/0xa0
[   74.813869]  jbd2_journal_commit_transaction.cold+0xa1/0x148
[   74.817550]  kjournald2+0xf8/0x3e0
[   74.819056]  kthread+0x153/0x1c0
[   74.819963]  ret_from_fork+0x22/0x30

Above issue may happen as follows:
        write                   truncate                   kjournald2
generic_perform_write
 ext4_write_begin
  ext4_walk_page_buffers
   do_journal_get_write_access -&gt;add BJ_Reserved list
 ext4_journalled_write_end
  ext4_walk_page_buffers
   write_end_fn
    ext4_handle_dirty_metadata
                ***************JBD2 ABORT**************
     jbd2_journal_dirty_metadata
 -&gt; return -EROFS, jh in reserved_list
                                                   jbd2_journal_commit_transaction
                                                    while (commit_transaction-&gt;t_reserved_list)
                                                      jh = commit_transaction-&gt;t_reserved_list;
                        truncate_pagecache_range
                         do_invalidatepage
			  ext4_journalled_invalidatepage
			   jbd2_journal_invalidatepage
			    journal_unmap_buffer
			     __dispose_buffer
			      __jbd2_journal_unfile_buffer
			       jbd2_journal_put_journal_head -&gt;put last ref_count
			        __journal_remove_journal_head
				 bh-&gt;b_private = NULL;
				 jh-&gt;b_bh = NULL;
				                      jbd2_journal_refile_buffer(journal, jh);
							bh = jh2bh(jh);
							-&gt;bh is NULL, later will trigger null-ptr-deref
				 journal_free_journal_head(jh);

After commit 96f1e0974575, we no longer hold the j_state_lock while
iterating over the list of reserved handles in
jbd2_journal_commit_transaction().  This potentially allows the
journal_head to be freed by journal_unmap_buffer while the commit
codepath is also trying to free the BJ_Reserved buffers.  Keeping
j_state_lock held while trying extends hold time of the lock
minimally, and solves this issue.

Fixes: 96f1e0974575("jbd2: avoid long hold times of j_state_lock while committing a transaction")
Signed-off-by: Ye Bin &lt;yebin10@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20220317142137.1821590-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache</title>
<updated>2022-03-23T01:26:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-23T01:26:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6b1f86f8e9c7f9de7ca1cb987b2cf25e99b1ae3a'/>
<id>6b1f86f8e9c7f9de7ca1cb987b2cf25e99b1ae3a</id>
<content type='text'>
Pull filesystem folio updates from Matthew Wilcox:
 "Primarily this series converts some of the address_space operations to
  take a folio instead of a page.

  Notably:

   - a_ops-&gt;is_partially_uptodate() takes a folio instead of a page and
     changes the type of the 'from' and 'count' arguments to make it
     obvious they're bytes.

   - a_ops-&gt;invalidatepage() becomes -&gt;invalidate_folio() and has a
     similar type change.

   - a_ops-&gt;launder_page() becomes -&gt;launder_folio()

   - a_ops-&gt;set_page_dirty() becomes -&gt;dirty_folio() and adds the
     address_space as an argument.

  There are a couple of other misc changes up front that weren't worth
  separating into their own pull request"

* tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits)
  fs: Remove aops -&gt;set_page_dirty
  fb_defio: Use noop_dirty_folio()
  fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
  fs: Convert __set_page_dirty_buffers to block_dirty_folio
  nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio()
  mm: Convert swap_set_page_dirty() to swap_dirty_folio()
  ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio
  f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio
  f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio
  f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio
  afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio()
  btrfs: Convert extent_range_redirty_for_io() to use folios
  fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio
  btrfs: Convert from set_page_dirty to dirty_folio
  fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
  fs: Add aops-&gt;dirty_folio
  fs: Remove aops-&gt;launder_page
  orangefs: Convert launder_page to launder_folio
  nfs: Convert from launder_page to launder_folio
  fuse: Convert from launder_page to launder_folio
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull filesystem folio updates from Matthew Wilcox:
 "Primarily this series converts some of the address_space operations to
  take a folio instead of a page.

  Notably:

   - a_ops-&gt;is_partially_uptodate() takes a folio instead of a page and
     changes the type of the 'from' and 'count' arguments to make it
     obvious they're bytes.

   - a_ops-&gt;invalidatepage() becomes -&gt;invalidate_folio() and has a
     similar type change.

   - a_ops-&gt;launder_page() becomes -&gt;launder_folio()

   - a_ops-&gt;set_page_dirty() becomes -&gt;dirty_folio() and adds the
     address_space as an argument.

  There are a couple of other misc changes up front that weren't worth
  separating into their own pull request"

* tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits)
  fs: Remove aops -&gt;set_page_dirty
  fb_defio: Use noop_dirty_folio()
  fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
  fs: Convert __set_page_dirty_buffers to block_dirty_folio
  nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio()
  mm: Convert swap_set_page_dirty() to swap_dirty_folio()
  ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio
  f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio
  f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio
  f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio
  afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio()
  btrfs: Convert extent_range_redirty_for_io() to use folios
  fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio
  btrfs: Convert from set_page_dirty to dirty_folio
  fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
  fs: Add aops-&gt;dirty_folio
  fs: Remove aops-&gt;launder_page
  orangefs: Convert launder_page to launder_folio
  nfs: Convert from launder_page to launder_folio
  fuse: Convert from launder_page to launder_folio
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: Convert invalidatepage to invalidate_folio</title>
<updated>2022-03-15T12:23:30+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2022-02-09T20:21:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ccd16945dba091fdf1036d7711b9f6cbd287ae28'/>
<id>ccd16945dba091fdf1036d7711b9f6cbd287ae28</id>
<content type='text'>
Extensive changes, but fairly mechanical.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Tested-by: Damien Le Moal &lt;damien.lemoal@opensource.wdc.com&gt;
Acked-by: Damien Le Moal &lt;damien.lemoal@opensource.wdc.com&gt;
Tested-by: Mike Marshall &lt;hubcap@omnibond.com&gt; # orangefs
Tested-by: David Howells &lt;dhowells@redhat.com&gt; # afs
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Extensive changes, but fairly mechanical.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Tested-by: Damien Le Moal &lt;damien.lemoal@opensource.wdc.com&gt;
Acked-by: Damien Le Moal &lt;damien.lemoal@opensource.wdc.com&gt;
Tested-by: Mike Marshall &lt;hubcap@omnibond.com&gt; # orangefs
Tested-by: David Howells &lt;dhowells@redhat.com&gt; # afs
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd2: remove CONFIG_JBD2_DEBUG to update t_max_wait</title>
<updated>2022-02-26T02:28:58+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>riteshh@linux.ibm.com</email>
</author>
<published>2022-02-16T07:00:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2d4429205882817100e5e88870ce0663d30c77af'/>
<id>2d4429205882817100e5e88870ce0663d30c77af</id>
<content type='text'>
CONFIG_JBD2_DEBUG and jbd2_journal_enable_debug knobs were added in
update_t_max_wait(), since earlier it used to take a spinlock for
updating t_max_wait, which could cause a bottleneck while starting a
txn (start_this_handle()).

Since in previous patch, we have killed t_handle_lock completely, we
could get rid of this debug config and knob to let t_max_wait be
updated by default again.

Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/ad7319a601fd501079310747ce87d908e0944763.1644992076.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
CONFIG_JBD2_DEBUG and jbd2_journal_enable_debug knobs were added in
update_t_max_wait(), since earlier it used to take a spinlock for
updating t_max_wait, which could cause a bottleneck while starting a
txn (start_this_handle()).

Since in previous patch, we have killed t_handle_lock completely, we
could get rid of this debug config and knob to let t_max_wait be
updated by default again.

Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/ad7319a601fd501079310747ce87d908e0944763.1644992076.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd2: kill t_handle_lock transaction spinlock</title>
<updated>2022-02-26T02:28:13+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>riteshh@linux.ibm.com</email>
</author>
<published>2022-02-16T07:00:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f7f497cb702462e8505ff3d8d4e7722ad95626a1'/>
<id>f7f497cb702462e8505ff3d8d4e7722ad95626a1</id>
<content type='text'>
This patch kills t_handle_lock transaction spinlock completely from
jbd2.

To explain the reasoning, currently there were three sites at which
this spinlock was used.

1. jbd2_journal_wait_updates()
   a. Based on careful code review it can be seen that, we don't need this
      lock here. This is since we wait for any currently ongoing updates
      based on a atomic variable t_updates. And we anyway don't take any
      t_handle_lock while in stop_this_handle().
      i.e.

	write_lock(&amp;journal-&gt;j_state_lock()
	jbd2_journal_wait_updates() 			stop_this_handle()
		while (atomic_read(txn-&gt;t_updates) { 		|
		DEFINE_WAIT(wait); 				|
		prepare_to_wait(); 				|
		if (atomic_read(txn-&gt;t_updates) 		if (atomic_dec_and_test(txn-&gt;t_updates))
			write_unlock(&amp;journal-&gt;j_state_lock);
			schedule();					wake_up()
			write_lock(&amp;journal-&gt;j_state_lock);
		finish_wait();
	   }
	txn-&gt;t_state = T_COMMIT
	write_unlock(&amp;journal-&gt;j_state_lock);

   b.  Also note that between atomic_inc(&amp;txn-&gt;t_updates) in
       start_this_handle() and jbd2_journal_wait_updates(), the
       synchronization happens via read_lock(journal-&gt;j_state_lock) in
       start_this_handle();

2. jbd2_journal_extend()
   a. jbd2_journal_extend() is called with the handle of each process from
      task_struct. So no lock required in updating member fields of handle_t

   b. For member fields of h_transaction, all updates happens only via
      atomic APIs (which is also within read_lock()).
      So, no need of this transaction spinlock.

3. update_t_max_wait()
   Based on Jan suggestion, this can be carefully removed using atomic
   cmpxchg API.
   Note that there can be several processes which are waiting for a new
   transaction to be allocated and started. For doing this only one
   process will succeed in taking write_lock() and allocating a new txn.
   After that all of the process will be updating the t_max_wait (max
   transaction wait time). This can be done via below method w/o taking
   any locks using atomic cmpxchg.
   For more details refer [1]

	   new = get_new_val();
	   old = READ_ONCE(ptr-&gt;max_val);
	   while (old &lt; new)
		old = cmpxchg(&amp;ptr-&gt;max_val, old, new);

[1]: https://lwn.net/Articles/849237/

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/d89e599658b4a1f3893a48c6feded200073037fc.1644992076.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch kills t_handle_lock transaction spinlock completely from
jbd2.

To explain the reasoning, currently there were three sites at which
this spinlock was used.

1. jbd2_journal_wait_updates()
   a. Based on careful code review it can be seen that, we don't need this
      lock here. This is since we wait for any currently ongoing updates
      based on a atomic variable t_updates. And we anyway don't take any
      t_handle_lock while in stop_this_handle().
      i.e.

	write_lock(&amp;journal-&gt;j_state_lock()
	jbd2_journal_wait_updates() 			stop_this_handle()
		while (atomic_read(txn-&gt;t_updates) { 		|
		DEFINE_WAIT(wait); 				|
		prepare_to_wait(); 				|
		if (atomic_read(txn-&gt;t_updates) 		if (atomic_dec_and_test(txn-&gt;t_updates))
			write_unlock(&amp;journal-&gt;j_state_lock);
			schedule();					wake_up()
			write_lock(&amp;journal-&gt;j_state_lock);
		finish_wait();
	   }
	txn-&gt;t_state = T_COMMIT
	write_unlock(&amp;journal-&gt;j_state_lock);

   b.  Also note that between atomic_inc(&amp;txn-&gt;t_updates) in
       start_this_handle() and jbd2_journal_wait_updates(), the
       synchronization happens via read_lock(journal-&gt;j_state_lock) in
       start_this_handle();

2. jbd2_journal_extend()
   a. jbd2_journal_extend() is called with the handle of each process from
      task_struct. So no lock required in updating member fields of handle_t

   b. For member fields of h_transaction, all updates happens only via
      atomic APIs (which is also within read_lock()).
      So, no need of this transaction spinlock.

3. update_t_max_wait()
   Based on Jan suggestion, this can be carefully removed using atomic
   cmpxchg API.
   Note that there can be several processes which are waiting for a new
   transaction to be allocated and started. For doing this only one
   process will succeed in taking write_lock() and allocating a new txn.
   After that all of the process will be updating the t_max_wait (max
   transaction wait time). This can be done via below method w/o taking
   any locks using atomic cmpxchg.
   For more details refer [1]

	   new = get_new_val();
	   old = READ_ONCE(ptr-&gt;max_val);
	   while (old &lt; new)
		old = cmpxchg(&amp;ptr-&gt;max_val, old, new);

[1]: https://lwn.net/Articles/849237/

Suggested-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/d89e599658b4a1f3893a48c6feded200073037fc.1644992076.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd2: fix use-after-free of transaction_t race</title>
<updated>2022-02-26T02:28:10+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>riteshh@linux.ibm.com</email>
</author>
<published>2022-02-10T15:37:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cc16eecae687912238ee6efbff71ad31e2bc414e'/>
<id>cc16eecae687912238ee6efbff71ad31e2bc414e</id>
<content type='text'>
jbd2_journal_wait_updates() is called with j_state_lock held. But if
there is a commit in progress, then this transaction might get committed
and freed via jbd2_journal_commit_transaction() -&gt;
jbd2_journal_free_transaction(), when we release j_state_lock.
So check for journal-&gt;j_running_transaction everytime we release and
acquire j_state_lock to avoid use-after-free issue.

Link: https://lore.kernel.org/r/948c2fed518ae739db6a8f7f83f1d58b504f87d0.1644497105.git.ritesh.list@gmail.com
Fixes: 4f98186848707f53 ("jbd2: refactor wait logic for transaction updates into a common function")
Cc: stable@kernel.org
Reported-and-tested-by: syzbot+afa2ca5171d93e44b348@syzkaller.appspotmail.com
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
jbd2_journal_wait_updates() is called with j_state_lock held. But if
there is a commit in progress, then this transaction might get committed
and freed via jbd2_journal_commit_transaction() -&gt;
jbd2_journal_free_transaction(), when we release j_state_lock.
So check for journal-&gt;j_running_transaction everytime we release and
acquire j_state_lock to avoid use-after-free issue.

Link: https://lore.kernel.org/r/948c2fed518ae739db6a8f7f83f1d58b504f87d0.1644497105.git.ritesh.list@gmail.com
Fixes: 4f98186848707f53 ("jbd2: refactor wait logic for transaction updates into a common function")
Cc: stable@kernel.org
Reported-and-tested-by: syzbot+afa2ca5171d93e44b348@syzkaller.appspotmail.com
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4</title>
<updated>2022-02-06T18:34:45+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-02-06T18:34:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d8ad2ce873abab1cfd38779c626b79cef6307aac'/>
<id>d8ad2ce873abab1cfd38779c626b79cef6307aac</id>
<content type='text'>
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
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd2: fix kernel-doc descriptions for jbd2_journal_shrink_{scan,count}()</title>
<updated>2022-02-03T15:57:53+00:00</updated>
<author>
<name>Yang Li</name>
<email>yang.lee@linux.alibaba.com</email>
</author>
<published>2022-01-10T13:28:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=715a67f11d6755e0cc853ff4ef539f362b566096'/>
<id>715a67f11d6755e0cc853ff4ef539f362b566096</id>
<content type='text'>
Add the description of @shrink and @sc in jbd2_journal_shrink_scan() and
jbd2_journal_shrink_count() kernel-doc comment to remove warnings found
by running scripts/kernel-doc, which is caused by using 'make W=1'.
fs/jbd2/journal.c:1296: warning: Function parameter or member 'shrink'
not described in 'jbd2_journal_shrink_scan'
fs/jbd2/journal.c:1296: warning: Function parameter or member 'sc' not
described in 'jbd2_journal_shrink_scan'
fs/jbd2/journal.c:1320: warning: Function parameter or member 'shrink'
not described in 'jbd2_journal_shrink_count'
fs/jbd2/journal.c:1320: warning: Function parameter or member 'sc' not
described in 'jbd2_journal_shrink_count'

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Signed-off-by: Yang Li &lt;yang.lee@linux.alibaba.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20220110132841.34531-1-yang.lee@linux.alibaba.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the description of @shrink and @sc in jbd2_journal_shrink_scan() and
jbd2_journal_shrink_count() kernel-doc comment to remove warnings found
by running scripts/kernel-doc, which is caused by using 'make W=1'.
fs/jbd2/journal.c:1296: warning: Function parameter or member 'shrink'
not described in 'jbd2_journal_shrink_scan'
fs/jbd2/journal.c:1296: warning: Function parameter or member 'sc' not
described in 'jbd2_journal_shrink_scan'
fs/jbd2/journal.c:1320: warning: Function parameter or member 'shrink'
not described in 'jbd2_journal_shrink_count'
fs/jbd2/journal.c:1320: warning: Function parameter or member 'sc' not
described in 'jbd2_journal_shrink_count'

Reported-by: Abaci Robot &lt;abaci@linux.alibaba.com&gt;
Signed-off-by: Yang Li &lt;yang.lee@linux.alibaba.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20220110132841.34531-1-yang.lee@linux.alibaba.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd2: refactor wait logic for transaction updates into a common function</title>
<updated>2022-02-03T15:57:44+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>riteshh@linux.ibm.com</email>
</author>
<published>2022-01-17T12:11:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f98186848707f530669238d90e0562d92a78aab'/>
<id>4f98186848707f530669238d90e0562d92a78aab</id>
<content type='text'>
No functionality change as such in this patch. This only refactors the
common piece of code which waits for t_updates to finish into a common
function named as jbd2_journal_wait_updates(journal_t *)

Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/8c564f70f4b2591171677a2a74fccb22a7b6c3a4.1642416995.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functionality change as such in this patch. This only refactors the
common piece of code which waits for t_updates to finish into a common
function named as jbd2_journal_wait_updates(journal_t *)

Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/8c564f70f4b2591171677a2a74fccb22a7b6c3a4.1642416995.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
</feed>
