From: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx # v5.15+
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
