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| author |   Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-04-02 09:08:53 -0700 |
|---|---|---|
| committer |   Darrick J. Wong <darrick.wong@oracle.com> | 2020-04-02 09:08:53 -0700 |
| commit | 457df33e035a2cffc6561992f3f25a6c61605c46 (patch) | |
| tree | 3aa3c6f5ede2339ed4925a620aa7726c1a125502 /fs/iomap | |
| parent | iomap: fix comments in iomap_dio_rw (diff) | |
| download | wireguard-linux-457df33e035a2cffc6561992f3f25a6c61605c46.tar.xz wireguard-linux-457df33e035a2cffc6561992f3f25a6c61605c46.zip | |
iomap: Handle memory allocation failure in readahead
bio_alloc() can fail when we use GFP_NORETRY. If it does, allocate
a bio large enough for a single page like mpage_readpages() does.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/iomap')
| -rw-r--r-- | fs/iomap/buffered-io.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f080f542911b..56f2cca765be 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -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; |