mm/writeback: Add folio_wait_writeback()

wait_on_page_writeback_killable() only has one caller, so convert it to
call folio_wait_writeback_killable().  For the wait_on_page_writeback()
callers, add a compatibility wrapper around folio_wait_writeback().

Turning PageWriteback() into folio_test_writeback() eliminates a call
to compound_head() which saves 8 bytes and 15 bytes in the two
functions.  Unfortunately, that is more than offset by adding the
wait_on_page_writeback compatibility wrapper for a net increase in text
of 7 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>
This commit is contained in:
Matthew Wilcox (Oracle) 2021-03-04 11:09:17 -05:00
parent 4268b48077
commit 490e016f22
4 changed files with 46 additions and 20 deletions

View File

@ -861,7 +861,8 @@ int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
*/
vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
{
struct page *page = thp_head(vmf->page);
struct folio *folio = page_folio(vmf->page);
struct page *page = &folio->page;
struct file *file = vmf->vma->vm_file;
struct inode *inode = file_inode(file);
struct afs_vnode *vnode = AFS_FS_I(inode);
@ -884,7 +885,7 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
goto out;
#endif
if (wait_on_page_writeback_killable(page))
if (folio_wait_writeback_killable(folio))
goto out;
if (lock_page_killable(page) < 0)
@ -894,8 +895,8 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
* details the portion of the page we need to write back and we might
* need to redirty the page if there's a problem.
*/
if (wait_on_page_writeback_killable(page) < 0) {
unlock_page(page);
if (folio_wait_writeback_killable(folio) < 0) {
folio_unlock(folio);
goto out;
}

View File

@ -766,7 +766,8 @@ static inline int wait_on_page_locked_killable(struct page *page)
int put_and_wait_on_page_locked(struct page *page, int state);
void wait_on_page_writeback(struct page *page);
int wait_on_page_writeback_killable(struct page *page);
void folio_wait_writeback(struct folio *folio);
int folio_wait_writeback_killable(struct folio *folio);
void end_page_writeback(struct page *page);
void folio_end_writeback(struct folio *folio);
void wait_for_stable_page(struct page *page);

View File

@ -23,3 +23,9 @@ void end_page_writeback(struct page *page)
return folio_end_writeback(page_folio(page));
}
EXPORT_SYMBOL(end_page_writeback);
void wait_on_page_writeback(struct page *page)
{
return folio_wait_writeback(page_folio(page));
}
EXPORT_SYMBOL_GPL(wait_on_page_writeback);

View File

@ -2873,33 +2873,51 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
}
EXPORT_SYMBOL(__test_set_page_writeback);
/*
* Wait for a page to complete writeback
/**
* folio_wait_writeback - Wait for a folio to finish writeback.
* @folio: The folio to wait for.
*
* If the folio is currently being written back to storage, wait for the
* I/O to complete.
*
* Context: Sleeps. Must be called in process context and with
* no spinlocks held. Caller should hold a reference on the folio.
* If the folio is not locked, writeback may start again after writeback
* has finished.
*/
void wait_on_page_writeback(struct page *page)
void folio_wait_writeback(struct folio *folio)
{
while (PageWriteback(page)) {
trace_wait_on_page_writeback(page, page_mapping(page));
wait_on_page_bit(page, PG_writeback);
while (folio_test_writeback(folio)) {
trace_wait_on_page_writeback(&folio->page, folio_mapping(folio));
wait_on_page_bit(&folio->page, PG_writeback);
}
}
EXPORT_SYMBOL_GPL(wait_on_page_writeback);
EXPORT_SYMBOL_GPL(folio_wait_writeback);
/*
* Wait for a page to complete writeback. Returns -EINTR if we get a
* fatal signal while waiting.
/**
* folio_wait_writeback_killable - Wait for a folio to finish writeback.
* @folio: The folio to wait for.
*
* If the folio is currently being written back to storage, wait for the
* I/O to complete or a fatal signal to arrive.
*
* Context: Sleeps. Must be called in process context and with
* no spinlocks held. Caller should hold a reference on the folio.
* If the folio is not locked, writeback may start again after writeback
* has finished.
* Return: 0 on success, -EINTR if we get a fatal signal while waiting.
*/
int wait_on_page_writeback_killable(struct page *page)
int folio_wait_writeback_killable(struct folio *folio)
{
while (PageWriteback(page)) {
trace_wait_on_page_writeback(page, page_mapping(page));
if (wait_on_page_bit_killable(page, PG_writeback))
while (folio_test_writeback(folio)) {
trace_wait_on_page_writeback(&folio->page, folio_mapping(folio));
if (wait_on_page_bit_killable(&folio->page, PG_writeback))
return -EINTR;
}
return 0;
}
EXPORT_SYMBOL_GPL(wait_on_page_writeback_killable);
EXPORT_SYMBOL_GPL(folio_wait_writeback_killable);
/**
* wait_for_stable_page() - wait for writeback to finish, if necessary.