linux-toradex.git/fs/ext4/indirect.c, branch v6.7

ext4: only update i_reserved_data_blocks on successful block allocation

2023-06-26T23:34:56+00:00

In our fault injection test, we create an ext4 file, migrate it to
non-extent based file, then punch a hole and finally trigger a WARN_ON
in the ext4_da_update_reserve_space():

EXT4-fs warning (device sda): ext4_da_update_reserve_space:369:
ino 14, used 11 with only 10 reserved data blocks

When writing back a non-extent based file, if we enable delalloc, the
number of reserved blocks will be subtracted from the number of blocks
mapped by ext4_ind_map_blocks(), and the extent status tree will be
updated. We update the extent status tree by first removing the old
extent_status and then inserting the new extent_status. If the block range
we remove happens to be in an extent, then we need to allocate another
extent_status with ext4_es_alloc_extent().

       use old    to remove   to add new
    |----------|------------|------------|
              old extent_status

The problem is that the allocation of a new extent_status failed due to a
fault injection, and __es_shrink() did not get free memory, resulting in
a return of -ENOMEM. Then do_writepages() retries after receiving -ENOMEM,
we map to the same extent again, and the number of reserved blocks is again
subtracted from the number of blocks in that extent. Since the blocks in
the same extent are subtracted twice, we end up triggering WARN_ON at
ext4_da_update_reserve_space() because used > ei->i_reserved_data_blocks.

For non-extent based file, we update the number of reserved blocks after
ext4_ind_map_blocks() is executed, which causes a problem that when we call
ext4_ind_map_blocks() to create a block, it doesn't always create a block,
but we always reduce the number of reserved blocks. So we move the logic
for updating reserved blocks to ext4_ind_map_blocks() to ensure that the
number of reserved blocks is updated only after we do succeed in allocating
some new blocks.

Fixes: 5f634d064c70 ("ext4: Fix quota accounting error with fallocate")
Cc: stable@kernel.org
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20230424033846.4732-2-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o

ext4: fix error code return to user-space in ext4_get_branch()

2022-12-09T02:49:24+00:00

If a block is out of range in ext4_get_branch(), -ENOMEM will be returned
to user-space.  Obviously, this error code isn't really useful.  This
patch fixes it by making sure the right error code (-EFSCORRUPTED) is
propagated to user-space.  EUCLEAN is more informative than ENOMEM.

Signed-off-by: Luís Henriques 
Link: https://lore.kernel.org/r/20221109181445.17843-1-lhenriques@suse.de
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: use ext4_debug() instead of jbd_debug()

2022-08-03T03:52:19+00:00

We use jbd_debug() in some places in ext4. It seems a bit strange to use
jbd2 debugging output function for ext4 code. Also these days
ext4_debug() uses dynamic printk so each debug message can be enabled /
disabled on its own so the time when it made some sense to have these
combined (to allow easier common selecting of messages to report) has
passed. Just convert all jbd_debug() uses in ext4 to ext4_debug().

Signed-off-by: Jan Kara 
Reviewed-by: Lukas Czerner 
Link: https://lore.kernel.org/r/20220608112355.4397-1-jack@suse.cz
Signed-off-by: Theodore Ts'o

fs/ext4: fix comments mentioning i_mutex

2022-02-03T15:57:53+00:00

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Signed-off-by: hongnanli 
Link: https://lore.kernel.org/r/20220121070611.21618-1-hongnan.li@linux.alibaba.com
Signed-off-by: Theodore Ts'o

ext4: Support for checksumming from journal triggers

2021-08-31T03:36:50+00:00

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

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

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

ext4: fix various seppling typos

2021-04-10T03:14:59+00:00

Signed-off-by: Bhaskar Chowdhury 
Link: https://lore.kernel.org/r/cover.1616840203.git.unixbhaskar@gmail.com
Signed-off-by: Theodore Ts'o

ext4: use ASSERT() to replace J_ASSERT()

2020-12-03T14:36:57+00:00

There are currently multiple forms of assertion, such as J_ASSERT().
J_ASEERT() is provided for the jbd module, which is a public module.
Maybe we should use custom ASSERT() like other file systems, such as
xfs, which would be better.

Signed-off-by: Chunguang Xu 
Reviewed-by: Andreas Dilger 
Link: https://lore.kernel.org/r/1604764698-4269-1-git-send-email-brookxu@tencent.com
Signed-off-by: Theodore Ts'o

ext4: use ext4_sb_bread() instead of sb_bread()

2020-10-18T14:37:14+00:00

We have already remove open codes that invoke helpers provide by
fs/buffer.c in all places reading metadata buffers. This patch switch to
use ext4_sb_bread() to replace all sb_bread() helpers, which is
ext4_read_bh() helper back end.

Signed-off-by: zhangyi (F) 
Link: https://lore.kernel.org/r/20200924073337.861472-7-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o

ext4: use common helpers in all places reading metadata buffers

2020-10-18T14:37:14+00:00

Revome all open codes that read metadata buffers, switch to use
ext4_read_bh_*() common helpers.

Signed-off-by: zhangyi (F) 
Suggested-by: Jan Kara 
Link: https://lore.kernel.org/r/20200924073337.861472-4-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o

ext4: add trace exit in exception path.

2020-10-18T14:36:59+00:00

Missing trace exit in exception path of ext4_sync_file and
ext4_ind_map_blocks.

Signed-off-by: Zhang Qilong 
Link: https://lore.kernel.org/r/20200921124738.23352-1-zhangqilong3@huawei.com
Signed-off-by: Theodore Ts'o