Commit 9744b923 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'iomap-5.7-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux 

Pull iomap fix from Darrick Wong:
 "Fix a problem in readahead where we can crash if we can't allocate a
  full bio due to GFP_NORETRY"

* tag 'iomap-5.7-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Handle memory allocation failure in readahead
parents d8fc9cde 457df33e

fs/iomap/buffered-io.c

+8 −0
Original line number Diff line number Diff line
@@ -302,6 +302,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 


	if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) {

		gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);

		gfp_t orig_gfp = gfp;

		int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;



		if (ctx->bio)
@@ -310,6 +311,13 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 
		if (ctx->is_readahead) /* same as readahead_gfp_mask */

			gfp |= __GFP_NORETRY | __GFP_NOWARN;

		ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs));

		/*

		 * If the bio_alloc fails, try it again for a single page to

		 * avoid having to deal with partial page reads.  This emulates

		 * what do_mpage_readpage does.

		 */

		if (!ctx->bio)

			ctx->bio = bio_alloc(orig_gfp, 1);

		ctx->bio->bi_opf = REQ_OP_READ;

		if (ctx->is_readahead)

			ctx->bio->bi_opf |= REQ_RAHEAD;

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