[PATCH 7.2 063/457] netfs: Fix netfs_read_gaps() to use separate sink folios

[PATCH 7.2 063/457] netfs: Fix netfs_read_gaps() to use separate sink folios

[Greg Kroah-Hartman]

7.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

[ Upstream commit fc3ae66514ca5e87251f79044236e3e8babd24a3 ]

Fix netfs_read_gaps() to use separate folios rather than re-using a single
sink folio to discard the unwanted data so that cifs checksum checking sees
all the data that was fetched.

Fixes: 7f84a7b9892d ("netfs: Make netfs_read_folio() handle streaming-write pages")
Reported-by: Frank Sorenson <sorenson@redhat.com>
Closes: https://lore.kernel.org/r/a385053c-1c4a-4060-a3bb-befa007ddb33@redhat.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/3228134.1789399227@warthog.procyon.org.uk
Tested-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Namjae Jeon <linkinjeon@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/netfs/buffered_read.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 424df70a5c30f..105194de6e13e 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -482,15 +482,14 @@ static int netfs_read_gaps(struct file *file, struct folio *folio)
 	struct netfs_group *group = netfs_folio_group(folio);
 	struct netfs_folio *finfo = netfs_folio_info(folio);
 	struct netfs_inode *ctx = netfs_inode(mapping->host);
-	struct folio *sink = NULL;
-	struct bio_vec *bvec;
+	struct bio_vec *bvec = NULL;
 	unsigned int from = finfo->dirty_offset;
 	unsigned int to = from + finfo->dirty_len;
-	unsigned int off = 0, i = 0;
+	unsigned int off = 0;
 	size_t flen = folio_size(folio);
 	size_t nr_bvec = flen / PAGE_SIZE + 2;
 	size_t part;
-	int ret;
+	int ret, i = 0, sink_from = -1, sink_to = -1;
 
 	_enter("%lx", folio->index);
 
@@ -515,24 +514,23 @@ static int netfs_read_gaps(struct file *file, struct folio *folio)
 	if (!bvec)
 		goto discard;
 
-	sink = folio_alloc(GFP_KERNEL, 0);
-	if (!sink) {
-		kfree(bvec);
-		goto discard;
-	}
-
 	trace_netfs_folio(folio, netfs_folio_trace_read_gaps);
 
-	rreq->direct_bv = bvec;
-	rreq->direct_bv_count = nr_bvec;
 	if (from > 0) {
 		bvec_set_folio(&bvec[i++], folio, from, 0);
 		off = from;
 	}
+	sink_from = i;
 	while (off < to) {
+		struct folio *sink = folio_alloc(GFP_KERNEL, 0);
+
+		if (!sink)
+			goto discard;
 		part = min_t(size_t, to - off, PAGE_SIZE);
-		bvec_set_folio(&bvec[i++], sink, part, 0);
+		bvec_set_folio(&bvec[i], sink, part, 0);
 		off += part;
+		sink_to = i;
+		i++;
 	}
 	if (to < flen)
 		bvec_set_folio(&bvec[i++], folio, flen - to, to);
@@ -553,8 +551,10 @@ static int netfs_read_gaps(struct file *file, struct folio *folio)
 		folio_mark_uptodate(folio);
 	}
 
-	if (sink)
-		folio_put(sink);
+	if (sink_to >= 0)
+		for (; sink_from <= sink_to; sink_from++)
+			folio_put(bvec_folio(&bvec[sink_from]));
+	kfree(bvec);
 	folio_unlock(folio);
 	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 	return ret < 0 ? ret : 0;
@@ -563,6 +563,10 @@ static int netfs_read_gaps(struct file *file, struct folio *folio)
 	netfs_put_failed_request(rreq);
 alloc_error:
 	folio_unlock(folio);
+	if (sink_to >= 0)
+		for (; sink_from <= sink_to; sink_from++)
+			folio_put(bvec_folio(&bvec[sink_from]));
+	kfree(bvec);
 	return ret;
 }
 
-- 
2.53.0

[PATCH 7.2 064/457] netfs, afs: Fix symlink reading

[Greg Kroah-Hartman]

7.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

[ Upstream commit c51e89c5b5db3e1927738fad7cd18b66dde68aed ]

Fix the reading of symlinks from the cache in afs by making netfslib trim
the amount read down to i_size.  The problem is that afs sets the size of
the iterator to the size of the buffer (PAGE_SIZE) so that the cache can
round the read size up to the cache's DIO size.

Note that this also impacts the reading of AFS mountpoints as they're just
stored as symlinks with an odd file mode.

Link: https://patch.msgid.link/3912795.1789489319@warthog.procyon.org.uk
Fixes: c0410adf3da6 ("afs: Fix the locking used by afs_get_link()")
Reviewed-by: Paulo Alcantara <pc@manguebit.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/netfs/read_collect.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c
index 5cf22087d2439..a94197ef01811 100644
--- a/fs/netfs/read_collect.c
+++ b/fs/netfs/read_collect.c
@@ -435,6 +435,11 @@ static void netfs_rreq_assess_single(struct netfs_io_request *rreq)
 		netfs_single_mark_inode_dirty(rreq->inode);
 	}
 
+	/* To do DIO, the cache has to round the size up, so we need to undo
+	 * the rounding.
+	 */
+	rreq->transferred = min(rreq->transferred, rreq->i_size);
+
 	if (rreq->iocb) {
 		rreq->iocb->ki_pos += rreq->transferred;
 		if (rreq->iocb->ki_complete) {
-- 
2.53.0