Commit Graph

169 Commits

Author SHA1 Message Date
Linus Torvalds
7856a56541 Many singleton patches - please see the various changelogs for details.
Quite a lot of nilfs2 work this time around.
 
 Notable patch series in this pull request are:
 
 "mul_u64_u64_div_u64: new implementation" by Nicolas Pitre, with
 assistance from Uwe Kleine-König.  Reimplement mul_u64_u64_div_u64() to
 provide (much) more accurate results.  The current implementation was
 causing Uwe some issues in the PWM drivers.
 
 "xz: Updates to license, filters, and compression options" from Lasse
 Collin.  Miscellaneous maintenance and kinor feature work to the xz
 decompressor.
 
 "Fix some GDB command error and add some GDB commands" from Kuan-Ying Lee.
 Fixes and enhancements to the gdb scripts.
 
 "treewide: add missing MODULE_DESCRIPTION() macros" from Jeff Johnson.
 Adds lots of MODULE_DESCRIPTIONs, thus fixing lots of warnings about this.
 
 "nilfs2: add support for some common ioctls" from Ryusuke Konishi.  Adds
 various commonly-available ioctls to nilfs2.
 
 "This series fixes a number of formatting issues in kernel doc comments"
 from Ryusuke Konishi does that.
 
 "nilfs2: prevent unexpected ENOENT propagation" from Ryusuke Konishi.  Fix
 issues where -ENOENT was being unintentionally and inappropriately
 returned to userspace.
 
 "nilfs2: assorted cleanups" from Huang Xiaojia.
 
 "nilfs2: fix potential issues with empty b-tree nodes" from Ryusuke
 Konishi fixes some issues which can occur on corrupted nilfs2 filesystems.
 
 "scripts/decode_stacktrace.sh: improve error reporting and usability" from
 Luca Ceresoli does those things.
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Merge tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Many singleton patches - please see the various changelogs for
  details.

  Quite a lot of nilfs2 work this time around.

  Notable patch series in this pull request are:

   - "mul_u64_u64_div_u64: new implementation" by Nicolas Pitre, with
     assistance from Uwe Kleine-König. Reimplement mul_u64_u64_div_u64()
     to provide (much) more accurate results. The current implementation
     was causing Uwe some issues in the PWM drivers.

   - "xz: Updates to license, filters, and compression options" from
     Lasse Collin. Miscellaneous maintenance and kinor feature work to
     the xz decompressor.

   - "Fix some GDB command error and add some GDB commands" from
     Kuan-Ying Lee. Fixes and enhancements to the gdb scripts.

   - "treewide: add missing MODULE_DESCRIPTION() macros" from Jeff
     Johnson. Adds lots of MODULE_DESCRIPTIONs, thus fixing lots of
     warnings about this.

   - "nilfs2: add support for some common ioctls" from Ryusuke Konishi.
     Adds various commonly-available ioctls to nilfs2.

   - "This series fixes a number of formatting issues in kernel doc
     comments" from Ryusuke Konishi does that.

   - "nilfs2: prevent unexpected ENOENT propagation" from Ryusuke
     Konishi. Fix issues where -ENOENT was being unintentionally and
     inappropriately returned to userspace.

   - "nilfs2: assorted cleanups" from Huang Xiaojia.

   - "nilfs2: fix potential issues with empty b-tree nodes" from Ryusuke
     Konishi fixes some issues which can occur on corrupted nilfs2
     filesystems.

   - "scripts/decode_stacktrace.sh: improve error reporting and
     usability" from Luca Ceresoli does those things"

* tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (103 commits)
  list: test: increase coverage of list_test_list_replace*()
  list: test: fix tests for list_cut_position()
  proc: use __auto_type more
  treewide: correct the typo 'retun'
  ocfs2: cleanup return value and mlog in ocfs2_global_read_info()
  nilfs2: remove duplicate 'unlikely()' usage
  nilfs2: fix potential oob read in nilfs_btree_check_delete()
  nilfs2: determine empty node blocks as corrupted
  nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
  user_namespace: use kmemdup_array() instead of kmemdup() for multiple allocation
  tools/mm: rm thp_swap_allocator_test when make clean
  squashfs: fix percpu address space issues in decompressor_multi_percpu.c
  lib: glob.c: added null check for character class
  nilfs2: refactor nilfs_segctor_thread()
  nilfs2: use kthread_create and kthread_stop for the log writer thread
  nilfs2: remove sc_timer_task
  nilfs2: do not repair reserved inode bitmap in nilfs_new_inode()
  nilfs2: eliminate the shared counter and spinlock for i_generation
  nilfs2: separate inode type information from i_state field
  nilfs2: use the BITS_PER_LONG macro
  ...
2024-09-21 08:20:50 -07:00
Ryusuke Konishi
74b0099340 nilfs2: refactor nilfs_segctor_thread()
Simplify nilfs_segctor_thread(), the main loop function of the log writer
thread, to make the basic structure easier to understand.

In particular, the acquisition and release of the sc_state_lock spinlock
was scattered throughout the function, so extract the determination of
whether log writing is required into a helper function and make the
spinlock lock sections clearer.

Link: https://lkml.kernel.org/r/20240826174116.5008-9-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:44 -07:00
Ryusuke Konishi
3f66cc261c nilfs2: use kthread_create and kthread_stop for the log writer thread
By using kthread_create() and kthread_stop() to start and stop the log
writer thread, eliminate custom thread start and stop helpers, as well as
the wait queue "sc_wait_task" on the "nilfs_sc_info" struct and
NILFS_SEGCTOR_QUIT flag that exist only to implement them.

Also, update the kernel doc comments of the changed functions as
appropriate.

Link: https://lkml.kernel.org/r/20240826174116.5008-8-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:44 -07:00
Ryusuke Konishi
cfdfe9e17c nilfs2: remove sc_timer_task
After commit f5d4e04634 ("nilfs2: fix use-after-free of timer for log
writer thread") is applied, nilfs_construct_timeout(), which is called by
a timer and wakes up the log writer thread, is never called after the log
writer thread has terminated.

As a result, the member variable "sc_timer_task" of the "nilfs_sc_info"
structure, which was added when timer_setup() was adopted to retain a
reference to the log writer thread's task even after it had terminated, is
no longer needed, as it should be; we can simply use "sc_task" instead,
which holds a reference to the log writer thread's task for its lifetime. 
So, eliminate "sc_timer_task" by this means.

Link: https://lkml.kernel.org/r/20240826174116.5008-7-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:43 -07:00
Ryusuke Konishi
d7cee0b342 nilfs2: separate inode type information from i_state field
In nilfs_iget_locked() and nilfs_ilookup(), which are used to find or
obtain nilfs2 inodes, the nilfs_iget_args structure used to identify
inodes has type information divided into multiple booleans, making type
determination complicated.

Simplify inode type determination by consolidating inode type information
into an unsigned integer represented by a comibination of flags and by
separating the type identification information for on-memory inodes from
the i_state member in the nilfs_inode_info structure.

Link: https://lkml.kernel.org/r/20240826174116.5008-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:43 -07:00
Ryusuke Konishi
0b9aad46c1 nilfs2: do not propagate ENOENT error from sufile during GC
nilfs_sufile_freev(), which is used to free segments in GC, aborts with
-ENOENT if the target segment usage is on a hole block.

This error only occurs if one of the segment numbers to be freed passed by
the GC ioctl is invalid, so return -EINVAL instead.

To avoid impairing readability, introduce a wrapper function that
encapsulates error handling including the error code conversion (and error
message output).

Link: https://lkml.kernel.org/r/20240821154627.11848-5-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:39 -07:00
Ryusuke Konishi
6576dd6695 nilfs2: fix state management in error path of log writing function
After commit a694291a62 ("nilfs2: separate wait function from
nilfs_segctor_write") was applied, the log writing function
nilfs_segctor_do_construct() was able to issue I/O requests continuously
even if user data blocks were split into multiple logs across segments,
but two potential flaws were introduced in its error handling.

First, if nilfs_segctor_begin_construction() fails while creating the
second or subsequent logs, the log writing function returns without
calling nilfs_segctor_abort_construction(), so the writeback flag set on
pages/folios will remain uncleared.  This causes page cache operations to
hang waiting for the writeback flag.  For example,
truncate_inode_pages_final(), which is called via nilfs_evict_inode() when
an inode is evicted from memory, will hang.

Second, the NILFS_I_COLLECTED flag set on normal inodes remain uncleared. 
As a result, if the next log write involves checkpoint creation, that's
fine, but if a partial log write is performed that does not, inodes with
NILFS_I_COLLECTED set are erroneously removed from the "sc_dirty_files"
list, and their data and b-tree blocks may not be written to the device,
corrupting the block mapping.

Fix these issues by uniformly calling nilfs_segctor_abort_construction()
on failure of each step in the loop in nilfs_segctor_do_construct(),
having it clean up logs and segment usages according to progress, and
correcting the conditions for calling nilfs_redirty_inodes() to ensure
that the NILFS_I_COLLECTED flag is cleared.

Link: https://lkml.kernel.org/r/20240814101119.4070-1-konishi.ryusuke@gmail.com
Fixes: a694291a62 ("nilfs2: separate wait function from nilfs_segctor_write")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 17:59:00 -07:00
Ryusuke Konishi
0f3819e8c4 nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro
According to the C standard 3.4.3p3, the result of signed integer overflow
is undefined.  The macro nilfs_cnt32_ge(), which compares two sequence
numbers, uses signed integer subtraction that can overflow, and therefore
the result of the calculation may differ from what is expected due to
undefined behavior in different environments.

Similar to an earlier change to the jiffies-related comparison macros in
commit 5a581b367b ("jiffies: Avoid undefined behavior from signed
overflow"), avoid this potential issue by changing the definition of the
macro to perform the subtraction as unsigned integers, then cast the
result to a signed integer for comparison.

Link: https://lkml.kernel.org/r/20130727225828.GA11864@linux.vnet.ibm.com
Link: https://lkml.kernel.org/r/20240702183512.6390-1-konishi.ryusuke@gmail.com
Fixes: 9ff05123e3 ("nilfs2: segment constructor")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 23:43:11 -07:00
Ryusuke Konishi
68142cb628 nilfs2: do not call inode_attach_wb() directly
Call mark_buffer_dirty() for segment summary and super root block buffers
on the backing device's page cache, thereby indirectly calling
inode_attach_wb().

Then remove the no longer needed call to inode_attach_wb() in
nilfs_attach_log_writer(), resolving the concern about its layer-violating
use.

Link: https://lkml.kernel.org/r/20240610160029.7673-3-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24 22:25:09 -07:00
Ryusuke Konishi
25fa5f9923 nilfs2: prepare backing device folios for writing after adding checksums
Patch series "nilfs2: eliminate the call to inode_attach_wb()".

This series eliminates the inode_attach_wb() call from nilfs2, which was
introduced as a workaround for a kernel bug but is suspected of layer
violation (in fact, it is undesirable since it exposes a reference to the
backing device).

Removal of the inode_attach_wb() call is done by simply using
mark_buffer_dirty() on the backing device's buffers.  To use it safely,
this series will prepare it in patch 1/2, and perform the replacement
itself in patch 2/2.


This patch (of 2):

In preparation for inode_attach_wb(), which is currently called when
attaching the log writer, to be done via mark_buffer_dirty(), change the
order of preparation for log writing.

Specifically, the function call that adds checksums to segment summary and
super root blocks, which correspond to the log header and trailer, is made
before starting writeback of folios containing those blocks.

The current steps are as follows:

1. Put the folios of segment summary blocks in writeback state.
2. Put the folios of data blocks, metadata file blocks, and btree node
   blocks (collectively called payload blocks) into writeback state.
3. Put the super root block folio in writeback state.
4. Add checksums.

Change these as follows:

1. Put the folios of payload blocks in writeback state.
2. Add checksums.
3. Put the folios of segment summary blocks in writeback state.
4. Put the super root block folio in writeback state.

In this order, the contents of segment summaries and super root block
that directly use buffer/folio of the backing device can be determined
including the addition of checksums, before preparing to write.

Step (1), which puts the payload block folios in writeback state, is
performed first because if there are memory-mapped data blocks, a valid
checksum can only be calculated after step (1).

Link: https://lkml.kernel.org/r/20240610160029.7673-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24 22:25:09 -07:00
Ryusuke Konishi
a4ca369ca2 nilfs2: fix potential kernel bug due to lack of writeback flag waiting
Destructive writes to a block device on which nilfs2 is mounted can cause
a kernel bug in the folio/page writeback start routine or writeback end
routine (__folio_start_writeback in the log below):

 kernel BUG at mm/page-writeback.c:3070!
 Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
 ...
 RIP: 0010:__folio_start_writeback+0xbaa/0x10e0
 Code: 25 ff 0f 00 00 0f 84 18 01 00 00 e8 40 ca c6 ff e9 17 f6 ff ff
  e8 36 ca c6 ff 4c 89 f7 48 c7 c6 80 c0 12 84 e8 e7 b3 0f 00 90 <0f>
  0b e8 1f ca c6 ff 4c 89 f7 48 c7 c6 a0 c6 12 84 e8 d0 b3 0f 00
 ...
 Call Trace:
  <TASK>
  nilfs_segctor_do_construct+0x4654/0x69d0 [nilfs2]
  nilfs_segctor_construct+0x181/0x6b0 [nilfs2]
  nilfs_segctor_thread+0x548/0x11c0 [nilfs2]
  kthread+0x2f0/0x390
  ret_from_fork+0x4b/0x80
  ret_from_fork_asm+0x1a/0x30
  </TASK>

This is because when the log writer starts a writeback for segment summary
blocks or a super root block that use the backing device's page cache, it
does not wait for the ongoing folio/page writeback, resulting in an
inconsistent writeback state.

Fix this issue by waiting for ongoing writebacks when putting
folios/pages on the backing device into writeback state.

Link: https://lkml.kernel.org/r/20240530141556.4411-1-konishi.ryusuke@gmail.com
Fixes: 9ff05123e3 ("nilfs2: segment constructor")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 19:19:24 -07:00
Ryusuke Konishi
eb85dace89 nilfs2: fix potential hang in nilfs_detach_log_writer()
Syzbot has reported a potential hang in nilfs_detach_log_writer() called
during nilfs2 unmount.

Analysis revealed that this is because nilfs_segctor_sync(), which
synchronizes with the log writer thread, can be called after
nilfs_segctor_destroy() terminates that thread, as shown in the call trace
below:

nilfs_detach_log_writer
  nilfs_segctor_destroy
    nilfs_segctor_kill_thread  --> Shut down log writer thread
    flush_work
      nilfs_iput_work_func
        nilfs_dispose_list
          iput
            nilfs_evict_inode
              nilfs_transaction_commit
                nilfs_construct_segment (if inode needs sync)
                  nilfs_segctor_sync  --> Attempt to synchronize with
                                          log writer thread
                           *** DEADLOCK ***

Fix this issue by changing nilfs_segctor_sync() so that the log writer
thread returns normally without synchronizing after it terminates, and by
forcing tasks that are already waiting to complete once after the thread
terminates.

The skipped inode metadata flushout will then be processed together in the
subsequent cleanup work in nilfs_segctor_destroy().

Link: https://lkml.kernel.org/r/20240520132621.4054-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+e3973c409251e136fdd0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e3973c409251e136fdd0
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: "Bai, Shuangpeng" <sjb7183@psu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-24 11:55:07 -07:00
Ryusuke Konishi
936184eadd nilfs2: fix unexpected freezing of nilfs_segctor_sync()
A potential and reproducible race issue has been identified where
nilfs_segctor_sync() would block even after the log writer thread writes a
checkpoint, unless there is an interrupt or other trigger to resume log
writing.

This turned out to be because, depending on the execution timing of the
log writer thread running in parallel, the log writer thread may skip
responding to nilfs_segctor_sync(), which causes a call to schedule()
waiting for completion within nilfs_segctor_sync() to lose the opportunity
to wake up.

The reason why waking up the task waiting in nilfs_segctor_sync() may be
skipped is that updating the request generation issued using a shared
sequence counter and adding an wait queue entry to the request wait queue
to the log writer, are not done atomically.  There is a possibility that
log writing and request completion notification by nilfs_segctor_wakeup()
may occur between the two operations, and in that case, the wait queue
entry is not yet visible to nilfs_segctor_wakeup() and the wake-up of
nilfs_segctor_sync() will be carried over until the next request occurs.

Fix this issue by performing these two operations simultaneously within
the lock section of sc_state_lock.  Also, following the memory barrier
guidelines for event waiting loops, move the call to set_current_state()
in the same location into the event waiting loop to ensure that a memory
barrier is inserted just before the event condition determination.

Link: https://lkml.kernel.org/r/20240520132621.4054-3-konishi.ryusuke@gmail.com
Fixes: 9ff05123e3 ("nilfs2: segment constructor")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: "Bai, Shuangpeng" <sjb7183@psu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-24 11:55:07 -07:00
Ryusuke Konishi
f5d4e04634 nilfs2: fix use-after-free of timer for log writer thread
Patch series "nilfs2: fix log writer related issues".

This bug fix series covers three nilfs2 log writer-related issues,
including a timer use-after-free issue and potential deadlock issue on
unmount, and a potential freeze issue in event synchronization found
during their analysis.  Details are described in each commit log.


This patch (of 3):

A use-after-free issue has been reported regarding the timer sc_timer on
the nilfs_sc_info structure.

The problem is that even though it is used to wake up a sleeping log
writer thread, sc_timer is not shut down until the nilfs_sc_info structure
is about to be freed, and is used regardless of the thread's lifetime.

Fix this issue by limiting the use of sc_timer only while the log writer
thread is alive.

Link: https://lkml.kernel.org/r/20240520132621.4054-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20240520132621.4054-2-konishi.ryusuke@gmail.com
Fixes: fdce895ea5 ("nilfs2: change sc_timer from a pointer to an embedded one in struct nilfs_sc_info")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: "Bai, Shuangpeng" <sjb7183@psu.edu>
Closes: https://groups.google.com/g/syzkaller/c/MK_LYqtt8ko/m/8rgdWeseAwAJ
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-24 11:55:07 -07:00
Linus Torvalds
38da32ee70 bd_inode series
Replacement of bdev->bd_inode with sane(r) set of primitives.
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Merge tag 'pull-bd_inode-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull bdev bd_inode updates from Al Viro:
 "Replacement of bdev->bd_inode with sane(r) set of primitives by me and
  Yu Kuai"

* tag 'pull-bd_inode-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RIP ->bd_inode
  dasd_format(): killing the last remaining user of ->bd_inode
  nilfs_attach_log_writer(): use ->bd_mapping->host instead of ->bd_inode
  block/bdev.c: use the knowledge of inode/bdev coallocation
  gfs2: more obvious initializations of mapping->host
  fs/buffer.c: massage the remaining users of ->bd_inode to ->bd_mapping
  blk_ioctl_{discard,zeroout}(): we only want ->bd_inode->i_mapping here...
  grow_dev_folio(): we only want ->bd_inode->i_mapping there
  use ->bd_mapping instead of ->bd_inode->i_mapping
  block_device: add a pointer to struct address_space (page cache of bdev)
  missing helpers: bdev_unhash(), bdev_drop()
  block: move two helpers into bdev.c
  block2mtd: prevent direct access of bd_inode
  dm-vdo: use bdev_nr_bytes(bdev) instead of i_size_read(bdev->bd_inode)
  blkdev_write_iter(): saner way to get inode and bdev
  bcachefs: remove dead function bdev_sectors()
  ext4: remove block_device_ejected()
  erofs_buf: store address_space instead of inode
  erofs: switch erofs_bread() to passing offset instead of block number
2024-05-21 09:51:42 -07:00
Matthew Wilcox (Oracle)
a7ac59f4f2 nilfs2: remove calls to folio_set_error() and folio_clear_error()
Nobody checks this flag on nilfs2 folios, stop setting and clearing it. 
That lets us simplify nilfs_end_folio_io() slightly.

Link: https://lkml.kernel.org/r/20240420025029.2166544-17-willy@infradead.org
Link: https://lkml.kernel.org/r/20240430050901.3239-1-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-11 15:51:43 -07:00
Al Viro
3386183382 nilfs_attach_log_writer(): use ->bd_mapping->host instead of ->bd_inode
I suspect that inode_attach_wb() use is rather unidiomatic, but
that's a separate story - in any case, its use is a few times
per mount *and* the route by which we access that inode is
"the host of address_space a page belongs to".

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-03 02:36:55 -04:00
Ryusuke Konishi
cce259b4c3 nilfs2: localize highmem mapping for checkpoint finalization within cpfile
Move the checkpoint finalization routine to the cpfile side, and make the
page mapping local and temporary.  And use kmap_local instead of kmap to
access the checkpoint entry page when finalizing a checkpoint.

In this conversion, some of the information on the checkpoint entry being
rewritten is passed through the arguments of the newly added method
nilfs_cpfile_finalize_checkpoint().

Link: https://lkml.kernel.org/r/20240122140202.6950-13-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:53 -08:00
Ryusuke Konishi
d37db936c5 nilfs2: localize highmem mapping for checkpoint creation within cpfile
In order to convert kmap() used in cpfile to kmap_local, first move the
checkpoint creation routine, which is one of the places where kmap is
used, to the cpfile side and make the page mapping local and temporary. 
And use kmap_local instead of kmap to access the checkpoint entry page
(and header block page) when generating a checkpoint.

Link: https://lkml.kernel.org/r/20240122140202.6950-12-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:53 -08:00
Ryusuke Konishi
7282f2ae81 nilfs2: convert ifile to use kmap_local
Convert deprecated kmap() and kmap_atomic() to use kmap_local for the
ifile metadata file used to manage disk inodes.

In some usages, calls to kmap_local and kunmap_local are split into
different helpers, but those usages can be safely changed to local thread
kmap.

Link: https://lkml.kernel.org/r/20240122140202.6950-11-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:53 -08:00
Ryusuke Konishi
9cced6a521 nilfs2: move nilfs_bmap_write call out of nilfs_write_inode_common
Before converting the disk inode management metadata file ifile, the call
to nilfs_bmap_write(), the i_device_code setting, and the zero-fill code
for inodes on the super root block are moved from
nilfs_write_inode_common() to its callers.

This cleanup simplifies the role and arguments of
nilfs_write_inode_common() and collects calls to nilfs_bmap_write() to the
log writing code.

Also, add and use a new helper nilfs_write_root_mdt_inode() to avoid code
duplication in the data export routine nilfs_segctor_fill_in_super_root()
to the super root block's buffer.

Link: https://lkml.kernel.org/r/20240122140202.6950-9-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:53 -08:00
Ryusuke Konishi
5bc09b397c nilfs2: fix potential bug in end_buffer_async_write
According to a syzbot report, end_buffer_async_write(), which handles the
completion of block device writes, may detect abnormal condition of the
buffer async_write flag and cause a BUG_ON failure when using nilfs2.

Nilfs2 itself does not use end_buffer_async_write().  But, the async_write
flag is now used as a marker by commit 7f42ec3941 ("nilfs2: fix issue
with race condition of competition between segments for dirty blocks") as
a means of resolving double list insertion of dirty blocks in
nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the
resulting crash.

This modification is safe as long as it is used for file data and b-tree
node blocks where the page caches are independent.  However, it was
irrelevant and redundant to also introduce async_write for segment summary
and super root blocks that share buffers with the backing device.  This
led to the possibility that the BUG_ON check in end_buffer_async_write
would fail as described above, if independent writebacks of the backing
device occurred in parallel.

The use of async_write for segment summary buffers has already been
removed in a previous change.

Fix this issue by removing the manipulation of the async_write flag for
the remaining super root block buffer.

Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com
Fixes: 7f42ec3941 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+5c04210f7c7f897c1e7f@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07 21:20:37 -08:00
Kevin Hao
5b130948d5 nilfs2: add missing set_freezable() for freezable kthread
The kernel thread function nilfs_segctor_thread() invokes the
try_to_freeze() in its loop.  But all the kernel threads are non-freezable
by default.  So if we want to make a kernel thread to be freezable, we
have to invoke set_freezable() explicitly.

Link: https://lkml.kernel.org/r/20231219090918.2329-1-konishi.ryusuke@gmail.com
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29 12:22:28 -08:00
Matthew Wilcox (Oracle)
ff5710c3f3 nilfs2: convert nilfs_segctor_prepare_write to use folios
Use the new folio APIs, saving 17 hidden calls to compound_head().

Link: https://lkml.kernel.org/r/20231114084436.2755-11-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 17:21:28 -08:00
Matthew Wilcox (Oracle)
6609e23576 nilfs2: convert to __nilfs_clear_folio_dirty()
All callers now have a folio, so convert to pass a folio.  No caller uses
the return value, so make it return void.  Removes a couple of hidden
calls to compound_head().

Link: https://lkml.kernel.org/r/20231114084436.2755-10-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 17:21:28 -08:00
Matthew Wilcox (Oracle)
36319c0c1c nilfs2: convert to nilfs_folio_buffers_clean()
All callers of nilfs_page_buffers_clean() now have a folio, so convert it
to take a folio.  While I'm at it, make it return a bool.

Link: https://lkml.kernel.org/r/20231114084436.2755-6-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 17:21:27 -08:00
Matthew Wilcox (Oracle)
3cd36212bf nilfs2: convert nilfs_segctor_complete_write to use folios
Use the new folio APIs, saving five calls to compound_head().  This
includes the last callers of nilfs_end_page_io(), so remove that too.

Link: https://lkml.kernel.org/r/20231114084436.2755-4-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 17:21:26 -08:00
Matthew Wilcox (Oracle)
50196f0081 nilfs2: convert nilfs_abort_logs to use folios
Use the new folio APIs, saving five hidden calls to compound_head().

Link: https://lkml.kernel.org/r/20231114084436.2755-3-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 17:21:26 -08:00
Matthew Wilcox (Oracle)
8f46eaf6fd nilfs2: add nilfs_end_folio_io()
Patch series "nilfs2: Folio conversions for file paths".

This series advances page->folio conversions for a wide range of nilfs2,
including its file operations, block routines, and the log writer's
writeback routines.  It doesn't cover large folios support, but it saves a
lot of hidden compound_head() calls while preserving the existing support
range behavior.

The original series in post [1] also covered directory-related page->folio
conversions, but that was put on hold because a regression was found in
testing, so this is an excerpt from the first half of the original post.

[1] https://lkml.kernel.org/r/20231106173903.1734114-1-willy@infradead.org

I tested this series in both 32-bit and 64-bit environments, switching
between normal and small block sizes.  I also reviewed all changes in all
patches to ensure they do not break existing behavior.  There were no
problems.


This patch (of 20):

This is the folio counterpart of the existing nilfs_end_page_io() which is
retained as a wrapper of nilfs_end_folio_io().  Replaces nine hidden calls
to compound_head() with one.

Link: https://lkml.kernel.org/r/20231114084436.2755-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20231114084436.2755-2-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 17:21:26 -08:00
Matthew Wilcox (Oracle)
0a88810d9b buffer: remove folio_create_empty_buffers()
With all users converted, remove the old create_empty_buffers() and rename
folio_create_empty_buffers() to create_empty_buffers().

Link: https://lkml.kernel.org/r/20231016201114.1928083-28-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25 16:47:10 -07:00
Matthew Wilcox (Oracle)
922b12eff0 nilfs2: convert nilfs_lookup_dirty_data_buffers to use folio_create_empty_buffers
This function was already using a folio, so this update to the new API
removes a single folio->page->folio conversion.

Link: https://lkml.kernel.org/r/20231016201114.1928083-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25 16:47:09 -07:00
Ryusuke Konishi
f83913f8c5 nilfs2: fix general protection fault in nilfs_lookup_dirty_data_buffers()
A syzbot stress test reported that create_empty_buffers() called from
nilfs_lookup_dirty_data_buffers() can cause a general protection fault.

Analysis using its reproducer revealed that the back reference "mapping"
from a page/folio has been changed to NULL after dirty page/folio gang
lookup in nilfs_lookup_dirty_data_buffers().

Fix this issue by excluding pages/folios from being collected if, after
acquiring a lock on each page/folio, its back reference "mapping" differs
from the pointer to the address space struct that held the page/folio.

Link: https://lkml.kernel.org/r/20230805132038.6435-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000002930a705fc32b231@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:07:21 -07:00
Ryusuke Konishi
f8654743a0 nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer().  Previously,
nilfs_evict_inode() could cause use-after-free read for nilfs_root if
inodes are left in "garbage_list" and released by nilfs_dispose_list at
the end of nilfs_detach_log_writer(), and this bug was fixed by commit
9b5a04ac3a ("nilfs2: fix use-after-free bug of nilfs_root in
nilfs_evict_inode()").

However, it turned out that there is another possibility of UAF in the
call path where mark_inode_dirty_sync() is called from iput():

nilfs_detach_log_writer()
  nilfs_dispose_list()
    iput()
      mark_inode_dirty_sync()
        __mark_inode_dirty()
          nilfs_dirty_inode()
            __nilfs_mark_inode_dirty()
              nilfs_load_inode_block() --> causes UAF of nilfs_root struct

This can happen after commit 0ae45f63d4 ("vfs: add support for a
lazytime mount option"), which changed iput() to call
mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME
flag and i_nlink is non-zero.

This issue appears after commit 28a65b49eb ("nilfs2: do not write dirty
data after degenerating to read-only") when using the syzbot reproducer,
but the issue has potentially existed before.

Fix this issue by adding a "purging flag" to the nilfs structure, setting
that flag while disposing the "garbage_list" and checking it in
__nilfs_mark_inode_dirty().

Unlike commit 9b5a04ac3a ("nilfs2: fix use-after-free bug of nilfs_root
in nilfs_evict_inode()"), this patch does not rely on ns_writer to
determine whether to skip operations, so as not to break recovery on
mount.  The nilfs_salvage_orphan_logs routine dirties the buffer of
salvaged data before attaching the log writer, so changing
__nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL
will cause recovery write to fail.  The purpose of using the cleanup-only
flag is to allow for narrowing of such conditions.

Link: https://lkml.kernel.org/r/20230728191318.33047-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+74db8b3087f293d3a13a@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000b4e906060113fd63@google.com
Fixes: 0ae45f63d4 ("vfs: add support for a lazytime mount option")
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:43 -07:00
Ryusuke Konishi
679bd7ebdd nilfs2: fix buffer corruption due to concurrent device reads
As a result of analysis of a syzbot report, it turned out that in three
cases where nilfs2 allocates block device buffers directly via sb_getblk,
concurrent reads to the device can corrupt the allocated buffers.

Nilfs2 uses sb_getblk for segment summary blocks, that make up a log
header, and the super root block, that is the trailer, and when moving and
writing the second super block after fs resize.

In any of these, since the uptodate flag is not set when storing metadata
to be written in the allocated buffers, the stored metadata will be
overwritten if a device read of the same block occurs concurrently before
the write.  This causes metadata corruption and misbehavior in the log
write itself, causing warnings in nilfs_btree_assign() as reported.

Fix these issues by setting an uptodate flag on the buffer head on the
first or before modifying each buffer obtained with sb_getblk, and
clearing the flag on failure.

When setting the uptodate flag, the lock_buffer/unlock_buffer pair is used
to perform necessary exclusive control, and the buffer is filled to ensure
that uninitialized bytes are not mixed into the data read from others.  As
for buffers for segment summary blocks, they are filled incrementally, so
if the uptodate flag was unset on their allocation, set the flag and zero
fill the buffer once at that point.

Also, regarding the superblock move routine, the starting point of the
memset call to zerofill the block is incorrectly specified, which can
cause a buffer overflow on file systems with block sizes greater than
4KiB.  In addition, if the superblock is moved within a large block, it is
necessary to assume the possibility that the data in the superblock will
be destroyed by zero-filling before copying.  So fix these potential
issues as well.

Link: https://lkml.kernel.org/r/20230609035732.20426-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+31837fe952932efc8fb9@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000030000a05e981f475@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 13:19:33 -07:00
Ryusuke Konishi
28a65b49eb nilfs2: do not write dirty data after degenerating to read-only
According to syzbot's report, mark_buffer_dirty() called from
nilfs_segctor_do_construct() outputs a warning with some patterns after
nilfs2 detects metadata corruption and degrades to read-only mode.

After such read-only degeneration, page cache data may be cleared through
nilfs_clear_dirty_page() which may also clear the uptodate flag for their
buffer heads.  However, even after the degeneration, log writes are still
performed by unmount processing etc., which causes mark_buffer_dirty() to
be called for buffer heads without the "uptodate" flag and causes the
warning.

Since any writes should not be done to a read-only file system in the
first place, this fixes the warning in mark_buffer_dirty() by letting
nilfs_segctor_do_construct() abort early if in read-only mode.

This also changes the retry check of nilfs_segctor_write_out() to avoid
unnecessary log write retries if it detects -EROFS that
nilfs_segctor_do_construct() returned.

Link: https://lkml.kernel.org/r/20230427011526.13457-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+2af3bc9585be7f23f290@syzkaller.appspotmail.com
  Link: https://syzkaller.appspot.com/bug?extid=2af3bc9585be7f23f290
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-06 10:10:07 -07:00
Ryusuke Konishi
ef832747a8 nilfs2: initialize unused bytes in segment summary blocks
Syzbot still reports uninit-value in nilfs_add_checksums_on_logs() for
KMSAN enabled kernels after applying commit 7397031622 ("nilfs2:
initialize "struct nilfs_binfo_dat"->bi_pad field").

This is because the unused bytes at the end of each block in segment
summaries are not initialized.  So this fixes the issue by padding the
unused bytes with null bytes.

Link: https://lkml.kernel.org/r/20230417173513.12598-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com
  Link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b
Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 14:22:14 -07:00
Ryusuke Konishi
6be49d100c nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()
The finalization of nilfs_segctor_thread() can race with
nilfs_segctor_kill_thread() which terminates that thread, potentially
causing a use-after-free BUG as KASAN detected.

At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member
of "struct nilfs_sc_info" to indicate the thread has finished, and then
notifies nilfs_segctor_kill_thread() of this using waitqueue
"sc_wait_task" on the struct nilfs_sc_info.

However, here, immediately after the NULL assignment to "sc_task", it is
possible that nilfs_segctor_kill_thread() will detect it and return to
continue the deallocation, freeing the nilfs_sc_info structure before the
thread does the notification.

This fixes the issue by protecting the NULL assignment to "sc_task" and
its notification, with spinlock "sc_state_lock" of the struct
nilfs_sc_info.  Since nilfs_segctor_kill_thread() does a final check to
see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate
the race.

Link: https://lkml.kernel.org/r/20230327175318.8060-1-konishi.ryusuke@gmail.com
Reported-by: syzbot+b08ebcc22f8f3e6be43a@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/00000000000000660d05f7dfa877@google.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 18:06:23 -07:00
Vishal Moola (Oracle)
a245865831 nilfs2: convert nilfs_lookup_dirty_node_buffers() to use filemap_get_folios_tag()
Convert function to use folios throughout.  This is in preparation for the
removal of find_get_pages_range_tag().  This change removes 1 call to
compound_head().

Link: https://lkml.kernel.org/r/20230104211448.4804-20-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:17 -08:00
Vishal Moola (Oracle)
5ee4b25cb7 nilfs2: convert nilfs_lookup_dirty_data_buffers() to use filemap_get_folios_tag()
Convert function to use folios throughout. This is in preparation for
the removal of find_get_pages_range_tag(). This change removes 4 calls
to compound_head().

Link: https://lkml.kernel.org/r/20230104211448.4804-19-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:17 -08:00
Matthew Wilcox (Oracle)
6ad4cd7f36 nilfs2: replace obvious uses of b_page with b_folio
These places just use b_page to get to the buffer's address_space or the
index of the page the buffer is in.

Link: https://lkml.kernel.org/r/20221215214402.3522366-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:41 -08:00
Steven Rostedt (Google)
292a089d78 treewide: Convert del_timer*() to timer_shutdown*()
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

    $ cat timer.cocci
    @@
    expression ptr, slab;
    identifier timer, rfield;
    @@
    (
    -       del_timer(&ptr->timer);
    +       timer_shutdown(&ptr->timer);
    |
    -       del_timer_sync(&ptr->timer);
    +       timer_shutdown_sync(&ptr->timer);
    )
      ... when strict
          when != ptr->timer
    (
            kfree_rcu(ptr, rfield);
    |
            kmem_cache_free(slab, ptr);
    |
            kfree(ptr);
    )

    $ spatch timer.cocci . > /tmp/t.patch
    $ patch -p1 < /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-12-25 13:38:09 -08:00
Ryusuke Konishi
8cccf05fe8 nilfs2: fix use-after-free bug of ns_writer on remount
If a nilfs2 filesystem is downgraded to read-only due to metadata
corruption on disk and is remounted read/write, or if emergency read-only
remount is performed, detaching a log writer and synchronizing the
filesystem can be done at the same time.

In these cases, use-after-free of the log writer (hereinafter
nilfs->ns_writer) can happen as shown in the scenario below:

 Task1                               Task2
 --------------------------------    ------------------------------
 nilfs_construct_segment
   nilfs_segctor_sync
     init_wait
     init_waitqueue_entry
     add_wait_queue
     schedule
                                     nilfs_remount (R/W remount case)
				       nilfs_attach_log_writer
                                         nilfs_detach_log_writer
                                           nilfs_segctor_destroy
                                             kfree
     finish_wait
       _raw_spin_lock_irqsave
         __raw_spin_lock_irqsave
           do_raw_spin_lock
             debug_spin_lock_before  <-- use-after-free

While Task1 is sleeping, nilfs->ns_writer is freed by Task2.  After Task1
waked up, Task1 accesses nilfs->ns_writer which is already freed.  This
scenario diagram is based on the Shigeru Yoshida's post [1].

This patch fixes the issue by not detaching nilfs->ns_writer on remount so
that this UAF race doesn't happen.  Along with this change, this patch
also inserts a few necessary read-only checks with superblock instance
where only the ns_writer pointer was used to check if the filesystem is
read-only.

Link: https://syzkaller.appspot.com/bug?id=79a4c002e960419ca173d55e863bd09e8112df8b
Link: https://lkml.kernel.org/r/20221103141759.1836312-1-syoshida@redhat.com [1]
Link: https://lkml.kernel.org/r/20221104142959.28296-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+f816fa82f8783f7a02bb@syzkaller.appspotmail.com
Reported-by: Shigeru Yoshida <syoshida@redhat.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 15:57:24 -08:00
Linus Torvalds
1440f57602 Five hotfixes - three for nilfs2, two for MM. For are cc:stable, one is
not.
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Merge tag 'mm-hotfixes-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "Five hotfixes - three for nilfs2, two for MM. For are cc:stable, one
  is not"

* tag 'mm-hotfixes-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  nilfs2: fix leak of nilfs_root in case of writer thread creation failure
  nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level()
  nilfs2: fix use-after-free bug of struct nilfs_root
  mm/damon/core: initialize damon_target->list in damon_new_target()
  mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page
2022-10-12 11:16:58 -07:00
Ryusuke Konishi
d0d51a9706 nilfs2: fix leak of nilfs_root in case of writer thread creation failure
If nilfs_attach_log_writer() failed to create a log writer thread, it
frees a data structure of the log writer without any cleanup.  After
commit e912a5b668 ("nilfs2: use root object to get ifile"), this causes
a leak of struct nilfs_root, which started to leak an ifile metadata inode
and a kobject on that struct.

In addition, if the kernel is booted with panic_on_warn, the above
ifile metadata inode leak will cause the following panic when the
nilfs2 kernel module is removed:

  kmem_cache_destroy nilfs2_inode_cache: Slab cache still has objects when
  called from nilfs_destroy_cachep+0x16/0x3a [nilfs2]
  WARNING: CPU: 8 PID: 1464 at mm/slab_common.c:494 kmem_cache_destroy+0x138/0x140
  ...
  RIP: 0010:kmem_cache_destroy+0x138/0x140
  Code: 00 20 00 00 e8 a9 55 d8 ff e9 76 ff ff ff 48 8b 53 60 48 c7 c6 20 70 65 86 48 c7 c7 d8 69 9c 86 48 8b 4c 24 28 e8 ef 71 c7 00 <0f> 0b e9 53 ff ff ff c3 48 81 ff ff 0f 00 00 77 03 31 c0 c3 53 48
  ...
  Call Trace:
   <TASK>
   ? nilfs_palloc_freev.cold.24+0x58/0x58 [nilfs2]
   nilfs_destroy_cachep+0x16/0x3a [nilfs2]
   exit_nilfs_fs+0xa/0x1b [nilfs2]
    __x64_sys_delete_module+0x1d9/0x3a0
   ? __sanitizer_cov_trace_pc+0x1a/0x50
   ? syscall_trace_enter.isra.19+0x119/0x190
   do_syscall_64+0x34/0x80
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   ...
   </TASK>
  Kernel panic - not syncing: panic_on_warn set ...

This patch fixes these issues by calling nilfs_detach_log_writer() cleanup
function if spawning the log writer thread fails.

Link: https://lkml.kernel.org/r/20221007085226.57667-1-konishi.ryusuke@gmail.com
Fixes: e912a5b668 ("nilfs2: use root object to get ifile")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+7381dc4ad60658ca4c05@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-11 19:05:45 -07:00
Ryusuke Konishi
723ac75120 nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
If creation or finalization of a checkpoint fails due to anomalies in the
checkpoint metadata on disk, a kernel warning is generated.

This patch replaces the WARN_ONs by nilfs_error, so that a kernel, booted
with panic_on_warn, does not panic.  A nilfs_error is appropriate here to
handle the abnormal filesystem condition.

This also replaces the detected error codes with an I/O error so that
neither of the internal error codes is returned to callers.

Link: https://lkml.kernel.org/r/20220929123330.19658-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+fbb3e0b24e8dae5a16ee@syzkaller.appspotmail.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-11 18:51:10 -07:00
ye xingchen
da6f79164e nilfs2: remove the unneeded result variable
Return the value nilfs_segctor_sync() directly instead of storing it in
another redundant variable.

Link: https://lkml.kernel.org/r/20220831033403.302184-1-ye.xingchen@zte.com.cn
Link: https://lkml.kernel.org/r/20220921034803.2476-3-konishi.ryusuke@gmail.com
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:21:44 -07:00
Ryusuke Konishi
e897be17a4 nilfs2: fix lockdep warnings in page operations for btree nodes
Patch series "nilfs2 lockdep warning fixes".

The first two are to resolve the lockdep warning issue, and the last one
is the accompanying cleanup and low priority.

Based on your comment, this series solves the issue by separating inode
object as needed.  Since I was worried about the impact of the object
composition changes, I tested the series carefully not to cause
regressions especially for delicate functions such like disk space
reclamation and snapshots.

This patch (of 3):

If CONFIG_LOCKDEP is enabled, nilfs2 hits lockdep warnings at
inode_to_wb() during page/folio operations for btree nodes:

  WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 inode_to_wb include/linux/backing-dev.h:269 [inline]
  WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 folio_account_dirtied mm/page-writeback.c:2460 [inline]
  WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 __folio_mark_dirty+0xa7c/0xe30 mm/page-writeback.c:2509
  Modules linked in:
  ...
  RIP: 0010:inode_to_wb include/linux/backing-dev.h:269 [inline]
  RIP: 0010:folio_account_dirtied mm/page-writeback.c:2460 [inline]
  RIP: 0010:__folio_mark_dirty+0xa7c/0xe30 mm/page-writeback.c:2509
  ...
  Call Trace:
    __set_page_dirty include/linux/pagemap.h:834 [inline]
    mark_buffer_dirty+0x4e6/0x650 fs/buffer.c:1145
    nilfs_btree_propagate_p fs/nilfs2/btree.c:1889 [inline]
    nilfs_btree_propagate+0x4ae/0xea0 fs/nilfs2/btree.c:2085
    nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337
    nilfs_collect_dat_data+0x45/0xd0 fs/nilfs2/segment.c:625
    nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1009
    nilfs_segctor_scan_file+0x47a/0x700 fs/nilfs2/segment.c:1048
    nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1224 [inline]
    nilfs_segctor_collect fs/nilfs2/segment.c:1494 [inline]
    nilfs_segctor_do_construct+0x14f3/0x6c60 fs/nilfs2/segment.c:2036
    nilfs_segctor_construct+0x7a7/0xb30 fs/nilfs2/segment.c:2372
    nilfs_segctor_thread_construct fs/nilfs2/segment.c:2480 [inline]
    nilfs_segctor_thread+0x3c3/0xf90 fs/nilfs2/segment.c:2563
    kthread+0x405/0x4f0 kernel/kthread.c:327
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

This is because nilfs2 uses two page caches for each inode and
inode->i_mapping never points to one of them, the btree node cache.

This causes inode_to_wb(inode) to refer to a different page cache than
the caller page/folio operations such like __folio_start_writeback(),
__folio_end_writeback(), or __folio_mark_dirty() acquired the lock.

This patch resolves the issue by allocating and using an additional
inode to hold the page cache of btree nodes.  The inode is attached
one-to-one to the traditional nilfs2 inode if it requires a block
mapping with b-tree.  This setup change is in memory only and does not
affect the disk format.

Link: https://lkml.kernel.org/r/1647867427-30498-1-git-send-email-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/1647867427-30498-2-git-send-email-konishi.ryusuke@gmail.com
Link: https://lore.kernel.org/r/YXrYvIo8YRnAOJCj@casper.infradead.org
Link: https://lore.kernel.org/r/9a20b33d-b38f-b4a2-4742-c1eb5b8e4d6c@redhat.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+0d5b462a6f07447991b3@syzkaller.appspotmail.com
Reported-by: syzbot+34ef28bb2aeb28724aa0@syzkaller.appspotmail.com
Reported-by: Hao Sun <sunhao.th@gmail.com>
Reported-by: David Hildenbrand <david@redhat.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-01 11:46:09 -07:00
Ryusuke Konishi
94ee1d9151 nilfs2: remove filenames from file comments
Remove filenames that are not particularly useful in file comments, and
suppress checkpatch warnings

  WARNING: It's generally not useful to have the filename in the file

Link: https://lkml.kernel.org/r/1635151862-11547-3-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Qing Wang <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:52 -08:00
Liu xuzhi
300563e6e0 fs/nilfs2: fix misspellings using codespell tool
Two typos are found out by codespell tool \
in 2217th and 2254th lines of segment.c:

$ codespell ./fs/nilfs2/
./segment.c:2217 :retured  ==> returned
./segment.c:2254: retured  ==> returned

Fix two typos found by codespell.

Link: https://lkml.kernel.org/r/1617864087-8198-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Liu xuzhi <liu.xuzhi@zte.com.cn>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:13 -07:00
Alex Shi
e7920b3e9d fs/nilfs2: remove some unused macros to tame gcc
There some macros are unused and cause gcc warning. Remove them.

  fs/nilfs2/segment.c:137:0: warning: macro "nilfs_cnt32_gt" is not used [-Wunused-macros]
  fs/nilfs2/segment.c:144:0: warning: macro "nilfs_cnt32_le" is not used [-Wunused-macros]
  fs/nilfs2/segment.c:143:0: warning: macro "nilfs_cnt32_lt" is not used [-Wunused-macros]

Link: https://lkml.kernel.org/r/1607552733-24292-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00