Re: [BUG?] invalidate_lock not held in read_cache_folio()

[Matthew Wilcox]

On Mon, Jun 08, 2026 at 04:54:51PM +0530, Dev Jain wrote:
> Hi,
> 
> My understanding is that there are two ways we are serializing against concurrent
> addition of a folio into the pagecache (see 730633f0b7f9).
> 
> The kerneldoc of read_cache_folio() says:
> 
> "Context: May sleep.  Expects mapping->invalidate_lock to be held."
> 
> I put the following in __filemap_add_folio():
> 
> +       BUG_ON(!inode_is_locked(mapping->host) &&
> +              !rwsem_is_locked(&mapping->invalidate_lock));
> 
> 
> And got the following trace:
> 
> 
> [    0.115587] Call trace:
> [    0.115686]  __filemap_add_folio+0x5dc/0x680 (P)
> [    0.115871]  filemap_add_folio+0xec/0x2d0
> [    0.116031]  do_read_cache_folio+0x144/0x2d8
> [    0.116194]  read_cache_folio+0x1c/0x30
> [    0.116344]  read_part_sector+0x4c/0xf0
> [    0.116499]  read_lba+0xb0/0x1a0
> [    0.116627]  efi_partition+0xa8/0x740
> [    0.116769]  bdev_disk_changed+0x238/0x620
> [    0.116939]  blkdev_get_whole+0xac/0x100
> [    0.117090]  bdev_open+0x280/0x3c0

You can't truncate or holepunch a bdev