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8 commits

Author SHA1 Message Date
Ksawlii
3b0ddcb83c Revert "ext4: fix incorrect tid assumption in ext4_wait_for_tail_page_commit()"
This reverts commit 4af33d15cb.
2024-11-24 00:23:03 +01:00
Luis Henriques (SUSE)
4af33d15cb ext4: fix incorrect tid assumption in ext4_wait_for_tail_page_commit()
commit dd589b0f1445e1ea1085b98edca6e4d5dedb98d0 upstream.

Function ext4_wait_for_tail_page_commit() assumes that '0' is not a valid
value for transaction IDs, which is incorrect.  Don't assume that and invoke
jbd2_log_wait_commit() if the journal had a committing transaction instead.

Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240724161119.13448-2-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:44 +01:00
Zhang Yi
0ffde1c603 ext4: check the extent status again before inserting delalloc block
[ Upstream commit 0ea6560abb3bac1ffcfa4bf6b2c4d344fdc27b3c ]

ext4_da_map_blocks looks up for any extent entry in the extent status
tree (w/o i_data_sem) and then the looks up for any ondisk extent
mapping (with i_data_sem in read mode).

If it finds a hole in the extent status tree or if it couldn't find any
entry at all, it then takes the i_data_sem in write mode to add a da
entry into the extent status tree. This can actually race with page
mkwrite & fallocate path.

Note that this is ok between
1. ext4 buffered-write path v/s ext4_page_mkwrite(), because of the
   folio lock
2. ext4 buffered write path v/s ext4 fallocate because of the inode
   lock.

But this can race between ext4_page_mkwrite() & ext4 fallocate path

ext4_page_mkwrite()             ext4_fallocate()
 block_page_mkwrite()
  ext4_da_map_blocks()
   //find hole in extent status tree
                                 ext4_alloc_file_blocks()
                                  ext4_map_blocks()
                                   //allocate block and unwritten extent
   ext4_insert_delayed_block()
    ext4_da_reserve_space()
     //reserve one more block
    ext4_es_insert_delayed_block()
     //drop unwritten extent and add delayed extent by mistake

Then, the delalloc extent is wrong until writeback and the extra
reserved block can't be released any more and it triggers below warning:

 EXT4-fs (pmem2): Inode 13 (00000000bbbd4d23): i_reserved_data_blocks(1) not cleared!

Fix the problem by looking up extent status tree again while the
i_data_sem is held in write mode. If it still can't find any entry, then
we insert a new da entry into the extent status tree.

Cc: stable@vger.kernel.org
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240517124005.347221-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:19 +01:00
Zhang Yi
e92b57698b ext4: factor out a common helper to query extent map
[ Upstream commit 8e4e5cdf2fdeb99445a468b6b6436ad79b9ecb30 ]

Factor out a new common helper ext4_map_query_blocks() from the
ext4_da_map_blocks(), it query and return the extent map status on the
inode's extent path, no logic changes.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/20240517124005.347221-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 0ea6560abb3b ("ext4: check the extent status again before inserting delalloc block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:19 +01:00
Zhang Yi
201f95d3a9 ext4: convert to exclusive lock while inserting delalloc extents
[ Upstream commit acf795dc161f3cf481db20f05db4250714e375e5 ]

ext4_da_map_blocks() only hold i_data_sem in shared mode and i_rwsem
when inserting delalloc extents, it could be raced by another querying
path of ext4_map_blocks() without i_rwsem, .e.g buffered read path.
Suppose we buffered read a file containing just a hole, and without any
cached extents tree, then it is raced by another delayed buffered write
to the same area or the near area belongs to the same hole, and the new
delalloc extent could be overwritten to a hole extent.

 pread()                           pwrite()
  filemap_read_folio()
   ext4_mpage_readpages()
    ext4_map_blocks()
     down_read(i_data_sem)
     ext4_ext_determine_hole()
     //find hole
     ext4_ext_put_gap_in_cache()
      ext4_es_find_extent_range()
      //no delalloc extent
                                    ext4_da_map_blocks()
                                     down_read(i_data_sem)
                                     ext4_insert_delayed_block()
                                     //insert delalloc extent
      ext4_es_insert_extent()
      //overwrite delalloc extent to hole

This race could lead to inconsistent delalloc extents tree and
incorrect reserved space counter. Fix this by converting to hold
i_data_sem in exclusive mode when adding a new delalloc extent in
ext4_da_map_blocks().

Cc: stable@vger.kernel.org
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240127015825.1608160-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 23:19:52 +01:00
Zhang Yi
42521c6986 ext4: refactor ext4_da_map_blocks()
[ Upstream commit 3fcc2b887a1ba4c1f45319cd8c54daa263ecbc36 ]

Refactor and cleanup ext4_da_map_blocks(), reduce some unnecessary
parameters and branches, no logic changes.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240127015825.1608160-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: acf795dc161f ("ext4: convert to exclusive lock while inserting delalloc extents")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 23:19:52 +01:00
Baokun Li
b5b208e51d ext4: make ext4_es_insert_extent() return void
[ Upstream commit 6c120399cde6b1b5cf65ce403765c579fb3d3e50 ]

Now ext4_es_insert_extent() never return error, so make it return void.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230424033846.4732-12-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: acf795dc161f ("ext4: convert to exclusive lock while inserting delalloc extents")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 23:19:51 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00