Commit b244c89a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Eric Biggers
Browse files

readahead: push invalidate_lock out of page_cache_ra_unbounded 



Require the invalidate_lock to be held over calls to
page_cache_ra_unbounded instead of acquiring it in this function.

This prepares for calling page_cache_ra_unbounded from ->readahead for
fsverity read-ahead.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20260202060754.270269-3-hch@lst.de


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent 23eec9fd

fs/f2fs/file.c

+2 −0
Original line number Diff line number Diff line
@@ -4418,7 +4418,9 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len) 
	pgoff_t redirty_idx = page_idx;

	int page_len = 0, ret = 0;



	filemap_invalidate_lock_shared(mapping);

	page_cache_ra_unbounded(&ractl, len, 0);

	filemap_invalidate_unlock_shared(mapping);



	do {

		folio = read_cache_folio(mapping, page_idx, NULL, NULL);

fs/verity/pagecache.c

+5 −2
Original line number Diff line number Diff line
@@ -26,10 +26,13 @@ struct page *generic_read_merkle_tree_page(struct inode *inode, pgoff_t index, 
	    (!IS_ERR(folio) && !folio_test_uptodate(folio))) {

		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);



		if (!IS_ERR(folio))

		if (!IS_ERR(folio)) {

			folio_put(folio);

		else if (num_ra_pages > 1)

		} else if (num_ra_pages > 1) {

			filemap_invalidate_lock_shared(inode->i_mapping);

			page_cache_ra_unbounded(&ractl, num_ra_pages, 0);

			filemap_invalidate_unlock_shared(inode->i_mapping);

		}

		folio = read_mapping_folio(inode->i_mapping, index, NULL);

	}

	if (IS_ERR(folio))

mm/readahead.c

+9 −6
Original line number Diff line number Diff line
@@ -204,8 +204,9 @@ static struct folio *ractl_alloc_folio(struct readahead_control *ractl, 
 * not the function you want to call.  Use page_cache_async_readahead()

 * or page_cache_sync_readahead() instead.

 *

 * Context: File is referenced by caller.  Mutexes may be held by caller.

 * May sleep, but will not reenter filesystem to reclaim memory.

 * Context: File is referenced by caller, and ractl->mapping->invalidate_lock

 * must be held by the caller at least in shared mode.  Mutexes may be held by

 * caller.  May sleep, but will not reenter filesystem to reclaim memory.

 */

void page_cache_ra_unbounded(struct readahead_control *ractl,

		unsigned long nr_to_read, unsigned long lookahead_size)
@@ -228,9 +229,10 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, 
	 */

	unsigned int nofs = memalloc_nofs_save();



	lockdep_assert_held(&mapping->invalidate_lock);



	trace_page_cache_ra_unbounded(mapping->host, index, nr_to_read,

				      lookahead_size);

	filemap_invalidate_lock_shared(mapping);

	index = mapping_align_index(mapping, index);



	/*
@@ -300,7 +302,6 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, 
	 * will then handle the error.

	 */

	read_pages(ractl);

	filemap_invalidate_unlock_shared(mapping);

	memalloc_nofs_restore(nofs);

}

EXPORT_SYMBOL_GPL(page_cache_ra_unbounded);
@@ -314,9 +315,9 @@ EXPORT_SYMBOL_GPL(page_cache_ra_unbounded); 
static void do_page_cache_ra(struct readahead_control *ractl,

		unsigned long nr_to_read, unsigned long lookahead_size)

{

	struct inode *inode = ractl->mapping->host;

	struct address_space *mapping = ractl->mapping;

	unsigned long index = readahead_index(ractl);

	loff_t isize = i_size_read(inode);

	loff_t isize = i_size_read(mapping->host);

	pgoff_t end_index;	/* The last page we want to read */



	if (isize == 0)
@@ -329,7 +330,9 @@ static void do_page_cache_ra(struct readahead_control *ractl, 
	if (nr_to_read > end_index - index)

		nr_to_read = end_index - index + 1;



	filemap_invalidate_lock_shared(mapping);

	page_cache_ra_unbounded(ractl, nr_to_read, lookahead_size);

	filemap_invalidate_unlock_shared(mapping);

}



/*