Hello:
This patch was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <[email protected]>:
On Tue, 25 Jun 2024 10:32:39 +0800 you wrote:
> Commit 59c9081bc86e ("f2fs: allow write page cache when writting cp")
> allows write() to write data to page cache during checkpoint, so block
> count fields like .total_valid_block_count, .alloc_valid_block_count
> and .rf_node_block_count may encounter race condition as below:
>
> CP Thread A
> - write_checkpoint
> - block_operations
> - f2fs_down_write(&sbi->node_change)
> - __prepare_cp_block
> : ckpt->valid_block_count = .total_valid_block_count
> - f2fs_up_write(&sbi->node_change)
> - write
> - f2fs_preallocate_blocks
> - f2fs_map_blocks(,F2FS_GET_BLOCK_PRE_AIO)
> - f2fs_map_lock
> - f2fs_down_read(&sbi->node_change)
> - f2fs_reserve_new_blocks
> - inc_valid_block_count
> :
> percpu_counter_add(&sbi->alloc_valid_block_count, count)
> : sbi->total_valid_block_count += count
> - f2fs_up_read(&sbi->node_change)
> - do_checkpoint
> : sbi->last_valid_block_count = sbi->total_valid_block_count
> : percpu_counter_set(&sbi->alloc_valid_block_count, 0)
> : percpu_counter_set(&sbi->rf_node_block_count, 0)
> - fsync
> - need_do_checkpoint
> - f2fs_space_for_roll_forward
> : alloc_valid_block_count was reset to zero,
> so, it may missed last data during
> checkpoint
>
> [...]
Here is the summary with links:
- [f2fs-dev,v2] f2fs: fix to update user block counts in block_operations()
https://git.kernel.org/jaegeuk/f2fs/c/f06c0f82e38b
You are awesome, thank you!
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