mm/writeback: Improve __folio_mark_dirty() comment

Add some notes about how this function needs to be called.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-12-20 06:44:51 -05:00
parent ece014141c
commit a229a4f00d

View File

@ -2496,7 +2496,11 @@ void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
* If warn is true, then emit a warning if the folio is not uptodate and has
* not been truncated.
*
* The caller must hold lock_page_memcg().
* The caller must hold lock_page_memcg(). Most callers have the folio
* locked. A few have the folio blocked from truncation through other
* means (eg zap_page_range() has it mapped and is holding the page table
* lock). This can also be called from mark_buffer_dirty(), which I
* cannot prove is always protected against truncate.
*/
void __folio_mark_dirty(struct folio *folio, struct address_space *mapping,
int warn)