Gao Xiang has reported that on ext4 O_SYNC direct IO does not properly
sync file size update and thus if we crash at unfortunate moment, the
file can have smaller size although O_SYNC IO has reported successful
completion. The problem happens because update of on-disk inode size is
handled in ext4_dio_write_iter() *after* iomap_dio_rw() (and thus
dio_complete() in particular) has returned and generic_file_sync() gets
called by dio_complete(). Fix the problem by handling on-disk inode size
update directly in our ->end_io completion handler.

References: https://lore.kernel.org/all/02d18236-26ef-09b0-90ad-030c4fe3ee20@linux.alibaba.comReported-by: Gao Xiang <hsiangkao@linux.alibaba.com>
CC: stable@vger.kernel.org
Fixes: 378f32ba ("ext4: introduce direct I/O write using iomap infrastructure")
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20231013121350.26872-1-jack@suse.czSigned-off-by: Theodore Ts'o <tytso@mit.edu>

syzbot reports that the following warning from ext4_iomap_begin()
triggers as of the commit referenced below:

        if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
                return -ERANGE;

This occurs during a dio write, which is never expected to encounter
an inode with inline data. To enforce this behavior,
ext4_dio_write_iter() checks the current inline state of the inode
and clears the MAY_INLINE_DATA state flag to either fall back to
buffered writes, or enforce that any other writers in progress on
the inode are not allowed to create inline data.

The problem is that the check for existing inline data and the state
flag can span a lock cycle. For example, if the ilock is originally
locked shared and subsequently upgraded to exclusive, another writer
may have reacquired the lock and created inline data before the dio
write task acquires the lock and proceeds.

The commit referenced below loosens the lock requirements to allow
some forms of unaligned dio writes to occur under shared lock, but
AFAICT the inline data check was technically already racy for any
dio write that would have involved a lock cycle. Regardless, lift
clearing of the state bit to the same lock critical section that
checks for preexisting inline data on the inode to close the race.

Cc: stable@kernel.org
Reported-by: syzbot+307da6ca5cb0d01d581a@syzkaller.appspotmail.com
Fixes: 310ee090 ("ext4: allow concurrent unaligned dio overwrites")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20231002185020.531537-1-bfoster@redhat.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Use KUNIT_CASE_PARAM to run mballoc test with different layouts setting.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-13-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Here are prepared work:
1. Include mballoc-test.c to mballoc.c to be able test static function
in mballoc.c.
2. Implement static stub to avoid read IO to disk.
3. Construct fake super_block. Only partial members are set, more members
will be set when more functions are tested.
Then unit test for ext4_mb_new_blocks_simple is added.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-12-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Multiblocks allocation will read and write block bitmap and group
descriptor which reside on disk. Add kunit stub to function
ext4_get_group_desc, ext4_read_block_bitmap_nowait, ext4_wait_block_bitmap
and ext4_mb_mark_context to avoid real IO to disk.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-11-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Call ext4_mb_mark_context in ext4_group_add_blocks() to remove repeat code.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-10-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

This patch separates block bitmap and buddy bitmap freeing in order to
update block bitmap with ext4_mb_mark_context in following patch.
The reason why this can be sperated is explained in previous submit.
Put the explanation here to simplify the code archeology to
ext4_group_add_blocks():

Separated freeing is safe with concurrent allocation as long as:
1. Firstly allocate block in buddy bitmap, and then in block bitmap.
2. Firstly free block in block bitmap, and then buddy bitmap.
Then freed block will only be available to allocation when both buddy
bitmap and block bitmap are updated by freeing.
Allocation obeys rule 1 already, just do sperated freeing with rule 2.

Separated freeing has no race with generate_buddy as:
Once ext4_mb_load_buddy_gfp is executed successfully, the update-to-date
buddy page can be found in sbi->s_buddy_cache and no more buddy
initialization of the buddy page will be executed concurrently until
buddy page is unloaded. As we always do free in "load buddy, free,
unload buddy" sequence, separated freeing has no race with generate_buddy.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-9-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Call ext4_mb_mark_context in ext4_mb_clear_bb to remove repeat code.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-8-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

This patch separates block bitmap and buddy bitmap freeing in order to
update block bitmap with ext4_mb_mark_context in following patch.

Separated freeing is safe with concurrent allocation as long as:
1. Firstly allocate block in buddy bitmap, and then in block bitmap.
2. Firstly free block in block bitmap, and then buddy bitmap.
Then freed block will only be available to allocation when both buddy
bitmap and block bitmap are updated by freeing.
Allocation obeys rule 1 already, just do sperated freeing with rule 2.

Separated freeing has no race with generate_buddy as:
Once ext4_mb_load_buddy_gfp is executed successfully, the update-to-date
buddy page can be found in sbi->s_buddy_cache and no more buddy
initialization of the buddy page will be executed concurrently until
buddy page is unloaded. As we always do free in "load buddy, free,
unload buddy" sequence, separated freeing has no race with generate_buddy.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-7-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Call ext4_mb_mark_context in ext4_mb_mark_diskspace_used to:
1. Remove repeat code to normally update bitmap and group descriptor
on disk.
2. Now that we have a common API for marking blocks inuse/free in block
bitmap, use that instead of open coding it in function
ext4_mb_mark_diskspace_used(). The current code was not updating
checksum and other counters. ext4_mb_mark_context() should fix these
consistency problems.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-6-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Previously, ext4_mb_mark_context is only called under fast commit
replay path, so there is no valid handle when we update block bitmap
and group descriptor. This patch try to extend ext4_mb_mark_context
to be used by code under journal. There are several improvement:
1. Add "handle_t *handle" to struct ext4_mark_context to journal block
bitmap and group descriptor update inside ext4_mb_mark_context (the
added journal code is based on ext4_mb_mark_diskspace_used where
ext4_mb_mark_context is going to be used.)
2. Adds a flag argument to ext4_mb_mark_context() which controls
a. EXT4_MB_BITMAP_MARKED_CHECK - whether block bitmap checking is needed.
b. EXT4_MB_SYNC_UPDATE - whether dirty buffers (bitmap and group
descriptor) needs sync.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-5-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

call ext4_mb_mark_context in ext4_free_blocks_simple to:
1. remove repeat code
2. pair update of free_clusters in ext4_mb_new_blocks_simple.
3. add missing ext4_lock_group/ext4_unlock_group protection.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-4-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

There are several reasons to add a general function ext4_mb_mark_context
to update block bitmap and group descriptor on disk:
1. pair behavior of alloc/free bits. For example,
ext4_mb_new_blocks_simple will update free_clusters in struct flex_groups
in ext4_mb_mark_bb while ext4_free_blocks_simple forgets this.
2. remove repeat code to read from disk, update and write back to disk.
3. reduce future unit test mocks to catch real IO to update structure
on disk.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-3-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

As state could only be either 0 or 1, just make it bool.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-2-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

JBD2 makes sure journal data is fallen on fs device by sync_blockdev(),
however, other process could intercept the EIO information from bdev's
mapping, which leads journal recovering successful even EIO occurs during
data written back to fs device.

We found this problem in our product, iscsi + multipath is chosen for block
device of ext4. Unstable network may trigger kpartx to rescan partitions in
device mapper layer. Detailed process is shown as following:

  mount          kpartx          irq
jbd2_journal_recover
 do_one_pass
  memcpy(nbh->b_data, obh->b_data) // copy data to fs dev from journal
  mark_buffer_dirty // mark bh dirty
         vfs_read
	  generic_file_read_iter // dio
	   filemap_write_and_wait_range
	    __filemap_fdatawrite_range
	     do_writepages
	      block_write_full_folio
	       submit_bh_wbc
	            >>  EIO occurs in disk  <<
	                     end_buffer_async_write
			      mark_buffer_write_io_error
			       mapping_set_error
			        set_bit(AS_EIO, &mapping->flags) // set!
	    filemap_check_errors
	     test_and_clear_bit(AS_EIO, &mapping->flags) // clear!
 err2 = sync_blockdev
  filemap_write_and_wait
   filemap_check_errors
    test_and_clear_bit(AS_EIO, &mapping->flags) // false
 err2 = 0

Filesystem is mounted successfully even data from journal is failed written
into disk, and ext4/ocfs2 could become corrupted.

Fix it by comparing the wb_err state in fs block device before recovering
and after recovering.

A reproducer can be found in the kernel bugzilla referenced below.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217888
Cc: stable@vger.kernel.org
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230919012525.1783108-1-chengzhihao1@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

The function ext4_init_acl() calls posix_acl_create() which is
responsible for applying the umask.  But without
CONFIG_EXT4_FS_POSIX_ACL, ext4_init_acl() is an empty inline function,
and nobody applies the umask.

This fixes a bug which causes the umask to be ignored with O_TMPFILE
on ext4:

 https://github.com/MusicPlayerDaemon/MPD/issues/558
 https://bugs.gentoo.org/show_bug.cgi?id=686142#c3
 https://bugzilla.kernel.org/show_bug.cgi?id=203625Reviewed-by: "J. Bruce Fields" <bfields@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Link: https://lore.kernel.org/r/20230919081824.1096619-1-max.kellermann@ionos.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

** Short Version **

In ext4 with dioread_nolock, we could have a scenario where the bh returned by
get_blocks (ext4_get_block_unwritten()) in __block_write_begin_int() has
UNWRITTEN and MAPPED flag set. Since such a bh does not have NEW flag set we
never zero out the range of bh that is not under write, causing whatever stale
data is present in the folio at that time to be written out to disk. To fix this
mark the buffer as new, in case it is unwritten, in ext4_get_block_unwritten().

** Long Version **

The issue mentioned above was resulting in two different bugs:

1. On block size < page size case in ext4, generic/269 was reliably
failing with dioread_nolock. The state of the write was as follows:

  * The write was extending i_size.
  * The last block of the file was fallocated and had an unwritten extent
  * We were near ENOSPC and hence we were switching to non-delayed alloc
    allocation.

In this case, the back trace that triggers the bug is as follows:

  ext4_da_write_begin()
    /* switch to nodelalloc due to low space */
    ext4_write_begin()
      ext4_should_dioread_nolock() // true since mount flags still have delalloc
      __block_write_begin(..., ext4_get_block_unwritten)
        __block_write_begin_int()
          for(each buffer head in page) {
            /* first iteration, this is bh1 which contains i_size */
            if (!buffer_mapped)
              get_block() /* returns bh with only UNWRITTEN and MAPPED */
            /* second iteration, bh2 */
              if (!buffer_mapped)
                get_block() /* we fail here, could be ENOSPC */
          }
          if (err)
            /*
             * this would zero out all new buffers and mark them uptodate.
             * Since bh1 was never marked new, we skip it here which causes
             * the bug later.
             */
            folio_zero_new_buffers();
      /* ext4_wrte_begin() error handling */
      ext4_truncate_failed_write()
        ext4_truncate()
          ext4_block_truncate_page()
            __ext4_block_zero_page_range()
              if(!buffer_uptodate())
                ext4_read_bh_lock()
                  ext4_read_bh() -> ... ext4_submit_bh_wbc()
                    BUG_ON(buffer_unwritten(bh)); /* !!! */

2. The second issue is stale data exposure with page size >= blocksize
with dioread_nolock. The conditions needed for it to happen are same as
the previous issue ie dioread_nolock around ENOSPC condition. The issue
is also similar where in __block_write_begin_int() when we call
ext4_get_block_unwritten() on the buffer_head and the underlying extent
is unwritten, we get an unwritten and mapped buffer head. Since it is
not new, we never zero out the partial range which is not under write,
thus writing stale data to disk. This can be easily observed with the
following reproducer:

 fallocate -l 4k testfile
 xfs_io -c "pwrite 2k 2k" testfile
 # hexdump output will have stale data in from byte 0 to 2k in testfile
 hexdump -C testfile

NOTE: To trigger this, we need dioread_nolock enabled and write happening via
ext4_write_begin(), which is usually used when we have -o nodealloc. Since
dioread_nolock is disabled with nodelalloc, the only alternate way to call
ext4_write_begin() is to ensure that delayed alloc switches to nodelalloc ie
ext4_da_write_begin() calls ext4_write_begin(). This will usually happen when
ext4 is almost full like the way generic/269 was triggering it in Issue 1 above.
This might make the issue harder to hit. Hence, for reliable replication, I used
the below patch to temporarily allow dioread_nolock with nodelalloc and then
mount the disk with -o nodealloc,dioread_nolock. With this you can hit the stale
data issue 100% of times:

@@ -508,8 +508,8 @@ static inline int ext4_should_dioread_nolock(struct inode *inode)
  if (ext4_should_journal_data(inode))
    return 0;
  /* temporary fix to prevent generic/422 test failures */
- if (!test_opt(inode->i_sb, DELALLOC))
-   return 0;
+ // if (!test_opt(inode->i_sb, DELALLOC))
+ //  return 0;
  return 1;
 }

After applying this patch to mark buffer as NEW, both the above issues are
fixed.
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Cc: stable@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/d0ed09d70a9733fbb5349c5c7b125caac186ecdf.1695033645.git.ojaswin@linux.ibm.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Check 'ix' before it is used.

Fixes: 80e675f9 ("ext4: optimize memmmove lengths in extent/index insertions")
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Link: https://lore.kernel.org/r/20230906013341.7199-1-gouhao@uniontech.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

'io_block' is unsinged long but print it by '%ld'.
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230904105817.1728356-3-yebin10@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Now, if check data block checksum failed only print data's block number
then skip write data. However, one data block may in more than one transaction.
In some scenarios, offline analysis is inconvenient. As a result, it is
difficult to locate the areas where data is faulty.
So print 'io_block' if check data block checksum failed.
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230904105817.1728356-2-yebin10@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

We always overwrite count2 to "EXT4_CLUSTERS_PER_GROUP(sb) -
(first_cluster - start)" after its initialization in for loop
initialization statement .
Just remove unnecessary initialization of count2.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-14-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

The sbi->s_group_desc contains array of bh's for block group descriptors
and continuous EXT4_DESC_PER_BLOCK(sb) bg descriptors in single block
share the same bh.
Simply call update_backups for each gdb_bh in sbi->s_group_desc will not
update same group descriptors block for multiple times.

Commit 0acdb887 ("ext4: don't call update_backups() multiple times for
the same bg") wrongly assumed each block group descriptor in the same block
has a individual bh and unnecessary check was added.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230826174712.4059355-13-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

We always call add_new_gdb_meta_bg with first group in mete_bg. Remove the
unnecessary ext4_meta_bg_first_group conversion to simplify the gdbblock
calculation.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230826174712.4059355-12-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

We save EXT4_SB(sb) to local variable sbi at beginning of function
ext4_resize_begin. Use sbi directly instead of EXT4_SB(sb) to
remove unnecessary pointer dereference.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-11-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Remove EXT4FS_DEBUG defination in resize.c for following reasons:
1. EXT4FS_DEBUG will enable debug messages, it should only be defined
when debugging.
2. ext4.h included from ext4_jbd2.h after EXT4FS_DEBUG defination will
"#undef EXT4FS_DEBUG", then EXT4FS_DEBUG defination in resize.c can't
actually turn on ext4_debug messages.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-10-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

The field free_cluster_count in struct ext4_new_group_data should be
in units of clusters.  In verify_group_input() this field is being
filled in units of blocks.  Fortunately, we don't support online
resizing of bigalloc file systems, and for non-bigalloc file systems,
the cluster size == block size.  But fix this in case we do support
online resizing of bigalloc file systems in the future.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-9-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Remove commented code in reserve_backup_gdb
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-8-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Remove zero check of count which is always non-zero.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-7-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

grop -> group
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-6-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Wrong check of gdb backup in meta bg as following:
first_group is the first group of meta_bg which contains target group, so
target group is always >= first_group. We check if target group has gdb
backup by comparing first_group with [group + 1] and [group +
EXT4_DESC_PER_BLOCK(sb) - 1]. As group >= first_group, then [group + N] is
> first_group. So no copy of gdb backup in meta bg is done in
setup_new_flex_group_blocks.

No need to do gdb backup copy in meta bg from setup_new_flex_group_blocks
as we always copy updated gdb block to backups at end of
ext4_flex_group_add as following:

ext4_flex_group_add
  /* no gdb backup copy for meta bg any more */
  setup_new_flex_group_blocks

  /* update current group number */
  ext4_update_super
    sbi->s_groups_count += flex_gd->count;

  /*
   * if group in meta bg contains backup is added, the primary gdb block
   * of the meta bg will be copy to backup in new added group here.
   */
  for (; gdb_num <= gdb_num_end; gdb_num++)
    update_backups(...)

In summary, we can remove wrong gdb backup copy code in
setup_new_flex_group_blocks.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-5-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Avoid to ignore error in "err".
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230826174712.4059355-4-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

add missed brelse in update_backups
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-3-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Commit 0aeaa255 ("ext4: fix corruption when online resizing a 1K
bigalloc fs") found that primary superblock's offset in its group is
not equal to offset of backup superblock in its group when block size
is 1K and bigalloc is enabled. As group descriptor blocks are right
after superblock, we can't pass block number of gdb to update_backups
for the same reason.

The root casue of the issue above is that leading 1K padding block is
count as data block offset for primary block while backup block has no
padding block offset in its group.

Remove padding data block count to fix the issue for gdb backups.

For meta_bg case, update_backups treat blk_off as block number, do no
conversion in this case.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20230826174712.4059355-2-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Commit 7a2fcbf7 ("ext4: don't use blocks freed but not yet committed in
buddy cache init") added a code to mark as used blocks in the list of not yet
committed freed blocks during initialization of a buddy page. However
ext4_mb_free_metadata() makes sure buddy page is already loaded and takes a
reference to it so it cannot happen that ext4_mb_init_cache() is called
when efd list is non-empty. Just remove the
ext4_mb_generate_from_freelist() call.

Fixes: 7a2fcbf7('ext4: don't use blocks freed but not yet committed in buddy cache init')
Signed-off-by: Wang Jianjian <wangjianjian0@foxmail.com>
Link: https://lore.kernel.org/r/tencent_53CBCB1668358AE862684E453DF37B722008@qq.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

The last argument of ext4_check_dir_entry is dentry offset int the
file.  Luckily this error only results in the wrong offset being
printed in the eventual error message.
Signed-off-by: Wang Jianjian <wangjianjian0@foxmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/tencent_F992989953734FD5DE3F88ECB2191A856206@qq.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

__insert_pending() allocate memory in atomic context, so the allocation
could fail, but we are not handling that failure now. It could lead
ext4_es_remove_extent() to get wrong reserved clusters, and the global
data blocks reservation count will be incorrect. The same to
extents_status entry preallocation, preallocate pending entry out of the
i_es_lock with __GFP_NOFAIL, make sure __insert_pending() and
__revise_pending() always succeeds.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230824092619.1327976-3-yi.zhang@huaweicloud.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

When big allocate feature is enabled, we need to count and update
reserved clusters before removing a delayed only extent_status entry.
{init|count|get}_rsvd() have already done this, but the start block
number of this counting isn't correct in the following case.

  lblk            end
   |               |
   v               v
          -------------------------
          |                       | orig_es
          -------------------------
                   ^              ^
      len1 is 0    |     len2     |

If the start block of the orig_es entry founded is bigger than lblk, we
passed lblk as start block to count_rsvd(), but the length is correct,
finally, the range to be counted is offset. This patch fix this by
passing the start blocks to 'orig_es->lblk + len1'.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230824092619.1327976-2-yi.zhang@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

When releasing space in jbd, we traverse s_freed_data_list to get the
free range belonging to the current commit transaction. In extreme cases,
the time spent may not be small, and we have observed cases exceeding
10ms. This patch makes running and commit transactions manage their own
free_data_list respectively, eliminating unnecessary traversal.

And in the callback phase of the commit transaction, no one will touch
it except the jbd thread itself, so s_md_lock is no longer needed.
Signed-off-by: Jinke Han <hanjinke.666@bytedance.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20230612124017.14115-1-hanjinke.666@bytedance.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

It would be better to replace the traditional ternary conditional
operator with max()/min()
Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
Reviewed-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230529070930.37949-1-luhongfei@vivo.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

We got a WARNING in ext4_add_complete_io:
==================================================================
 WARNING: at fs/ext4/page-io.c:231 ext4_put_io_end_defer+0x182/0x250
 CPU: 10 PID: 77 Comm: ksoftirqd/10 Tainted: 6.3.0-rc2 #85
 RIP: 0010:ext4_put_io_end_defer+0x182/0x250 [ext4]
 [...]
 Call Trace:
  <TASK>
  ext4_end_bio+0xa8/0x240 [ext4]
  bio_endio+0x195/0x310
  blk_update_request+0x184/0x770
  scsi_end_request+0x2f/0x240
  scsi_io_completion+0x75/0x450
  scsi_finish_command+0xef/0x160
  scsi_complete+0xa3/0x180
  blk_complete_reqs+0x60/0x80
  blk_done_softirq+0x25/0x40
  __do_softirq+0x119/0x4c8
  run_ksoftirqd+0x42/0x70
  smpboot_thread_fn+0x136/0x3c0
  kthread+0x140/0x1a0
  ret_from_fork+0x2c/0x50
==================================================================

Above issue may happen as follows:

            cpu1                        cpu2
----------------------------|----------------------------
mount -o dioread_lock
ext4_writepages
 ext4_do_writepages
  *if (ext4_should_dioread_nolock(inode))*
    // rsv_blocks is not assigned here
                                 mount -o remount,dioread_nolock
  ext4_journal_start_with_reserve
   __ext4_journal_start
    __ext4_journal_start_sb
     jbd2__journal_start
      *if (rsv_blocks)*
        // h_rsv_handle is not initialized here
  mpage_map_and_submit_extent
    mpage_map_one_extent
      dioread_nolock = ext4_should_dioread_nolock(inode)
      if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN))
        mpd->io_submit.io_end->handle = handle->h_rsv_handle
        ext4_set_io_unwritten_flag
          io_end->flag |= EXT4_IO_END_UNWRITTEN
      // now io_end->handle is NULL but has EXT4_IO_END_UNWRITTEN flag

scsi_finish_command
 scsi_io_completion
  scsi_io_completion_action
   scsi_end_request
    blk_update_request
     req_bio_endio
      bio_endio
       bio->bi_end_io  > ext4_end_bio
        ext4_put_io_end_defer
	 ext4_add_complete_io
	  // trigger WARN_ON(!io_end->handle && sbi->s_journal);

The immediate cause of this problem is that ext4_should_dioread_nolock()
function returns inconsistent values in the ext4_do_writepages() and
mpage_map_one_extent(). There are four conditions in this function that
can be changed at mount time to cause this problem. These four conditions
can be divided into two categories:

    (1) journal_data and EXT4_EXTENTS_FL, which can be changed by ioctl
    (2) DELALLOC and DIOREAD_NOLOCK, which can be changed by remount

The two in the first category have been fixed by commit c8585c6f
("ext4: fix races between changing inode journal mode and ext4_writepages")
and commit cb85f4d2 ("ext4: fix race between writepages and enabling
EXT4_EXTENTS_FL") respectively.

Two cases in the other category have not yet been fixed, and the above
issue is caused by this situation. We refer to the fix for the first
category, when applying options during remount, we grab s_writepages_rwsem
to avoid racing with writepages ops to trigger this problem.

Fixes: 6b523df4 ("ext4: use transaction reservation for extent conversion in ext4_end_io")
Cc: stable@vger.kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230524072538.2883391-1-libaokun1@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>