Commit cf948cbc authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
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cramfs: read_mapping_page() is synchronous 



Since commit 67f9fd91, the code to wait for the read to complete has
been dead.  That commit wrongly stated that the read was synchronous
already; this seems to have been a confusion about which ->readpage
operation was being called.  Instead of reintroducing an asynchronous
version of read_mapping_page(), call the readahead code directly to
submit all reads first before waiting for them in read_mapping_page().

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
parent 97a3a383

fs/cramfs/inode.c

+4 −13
Original line number Diff line number Diff line
@@ -183,6 +183,7 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, 
				unsigned int len)

{

	struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;

	struct file_ra_state ra;

	struct page *pages[BLKS_PER_BUF];

	unsigned i, blocknr, buffer;

	unsigned long devsize;
@@ -212,6 +213,9 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, 
	devsize = bdev_nr_bytes(sb->s_bdev) >> PAGE_SHIFT;



	/* Ok, read in BLKS_PER_BUF pages completely first. */

	file_ra_state_init(&ra, mapping);

	page_cache_sync_readahead(mapping, &ra, NULL, blocknr, BLKS_PER_BUF);



	for (i = 0; i < BLKS_PER_BUF; i++) {

		struct page *page = NULL;
@@ -224,19 +228,6 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, 
		pages[i] = page;

	}



	for (i = 0; i < BLKS_PER_BUF; i++) {

		struct page *page = pages[i];



		if (page) {

			wait_on_page_locked(page);

			if (!PageUptodate(page)) {

				/* asynchronous error */

				put_page(page);

				pages[i] = NULL;

			}

		}

	}



	buffer = next_buffer;

	next_buffer = NEXT_BUFFER(buffer);

	buffer_blocknr[buffer] = blocknr;