On 05.04.24 20:00, Matthew Wilcox (Oracle) wrote:
Remove four hidden calls to compound_head(). Also exit early if the filesystem block size is >= PAGE_SIZE instead of just equal to PAGE_SIZE. Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx> --- mm/truncate.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/mm/truncate.c b/mm/truncate.c index 725b150e47ac..e99085bf3d34 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -764,15 +764,15 @@ EXPORT_SYMBOL(truncate_setsize); * @from: original inode size * @to: new inode size * - * Handle extension of inode size either caused by extending truncate or by - * write starting after current i_size. We mark the page straddling current - * i_size RO so that page_mkwrite() is called on the nearest write access to - * the page. This way filesystem can be sure that page_mkwrite() is called on - * the page before user writes to the page via mmap after the i_size has been - * changed. + * Handle extension of inode size either caused by extending truncate or + * by write starting after current i_size. We mark the page straddling + * current i_size RO so that page_mkwrite() is called on the first + * write access to the page. The filesystem will update its per-block + * information before user writes to the page via mmap after the i_size + * has been changed.
Did you intend not to s/page/folio/ ?
* * The function must be called after i_size is updated so that page fault - * coming after we unlock the page will already see the new i_size. + * coming after we unlock the folio will already see the new i_size. * The function must be called while we still hold i_rwsem - this not only * makes sure i_size is stable but also that userspace cannot observe new * i_size value before we are prepared to store mmap writes at new inode size. @@ -781,31 +781,29 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> -- Cheers, David / dhildenb
