From: Andreas Gruenbacher agruenba@redhat.com
commit d8af404ffce71448f29bbc19a05e3d095baf98eb upstream.
Before commit 740499c78408 ("iomap: fix the iomap_readpage_actor return value for inline data"), when hitting an IOMAP_INLINE extent, iomap_readpage_actor would report having read the entire page. Since then, it only reports having read the inline data (iomap->length).
This will force iomap_readpage into another iteration, and the filesystem will report an unaligned hole after the IOMAP_INLINE extent. But iomap_readpage_actor (now iomap_readpage_iter) isn't prepared to deal with unaligned extents, it will get things wrong on filesystems with a block size smaller than the page size, and we'll eventually run into the following warning in iomap_iter_advance:
WARN_ON_ONCE(iter->processed > iomap_length(iter));
Fix that by changing iomap_readpage_iter to return 0 when hitting an inline extent; this will cause iomap_iter to stop immediately.
To fix readahead as well, change iomap_readahead_iter to pass on iomap_readpage_iter return values less than or equal to zero.
Fixes: 740499c78408 ("iomap: fix the iomap_readpage_actor return value for inline data") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/iomap/buffered-io.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -256,8 +256,13 @@ static loff_t iomap_readpage_iter(const unsigned poff, plen; sector_t sector;
- if (iomap->type == IOMAP_INLINE) - return min(iomap_read_inline_data(iter, page), length); + if (iomap->type == IOMAP_INLINE) { + loff_t ret = iomap_read_inline_data(iter, page); + + if (ret < 0) + return ret; + return 0; + }
/* zero post-eof blocks as the page may be mapped */ iop = iomap_page_create(iter->inode, page); @@ -370,6 +375,8 @@ static loff_t iomap_readahead_iter(const ctx->cur_page_in_bio = false; } ret = iomap_readpage_iter(iter, ctx, done); + if (ret <= 0) + return ret; }
return done;