[PATCH 6.11 034/558] afs: Fix missing wire-up of afs_retry_request()

[PATCH 6.11 034/558] afs: Fix missing wire-up of afs_retry_request()

[Greg Kroah-Hartman]

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

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

From: David Howells <dhowells@redhat.com>

[ Upstream commit 2cf36327ee1e47733aba96092d7bd082a4056ff5 ]

afs_retry_request() is supposed to be pointed to by the afs_req_ops netfs
operations table, but the pointer got lost somewhere.  The function is used
during writeback to rotate through the authentication keys that were in
force when the file was modified locally.

Fix this by adding the pointer to the function.

Fixes: 1ecb146f7cd8 ("netfs, afs: Use writeback retry to deal with alternate keys")
Reported-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/1690847.1726346402@warthog.procyon.org.uk
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/afs/file.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/afs/file.c b/fs/afs/file.c
index ec1be0091fdb5..290f60460ec75 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -404,6 +404,7 @@ const struct netfs_request_ops afs_req_ops = {
 	.begin_writeback	= afs_begin_writeback,
 	.prepare_write		= afs_prepare_write,
 	.issue_write		= afs_issue_write,
+	.retry_request		= afs_retry_request,
 };
 
 static void afs_add_open_mmap(struct afs_vnode *vnode)
-- 
2.43.0

[PATCH 6.11 046/558] netfs: Fix missing wakeup after issuing writes

[Greg Kroah-Hartman]

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

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

From: David Howells <dhowells@redhat.com>

[ Upstream commit 1ca4169c391c370e0f3a92938df2862900575096 ]

After dividing up a proposed write into subrequests, netfslib sets
NETFS_RREQ_ALL_QUEUED to indicate to the collector that it can move on to
the final cleanup once it has emptied the subrequest queues.

Now, whilst the collector will normally end up running at least once after
this bit is set just because it takes a while to process all the write
subrequests before the collector runs out of subrequests, there exists the
possibility that the issuing thread will be forced to sleep and the
collector thread will clean up all the subrequests before ALL_QUEUED gets
set.

In such a case, the collector thread will not get triggered again and will
never clear NETFS_RREQ_IN_PROGRESS thus leaving a request uncompleted and
causing a potential futute hang.

Fix this by scheduling the write collector if all the subrequest queues are
empty (and thus no writes pending issuance).

Note that we'd do this ideally before queuing the subrequest, but in the
case of buffered writeback, at least, we can't find out that we've run out
of folios until after we've called writeback_iter() and it has returned
NULL - at which point we might not actually have any subrequests still
under construction.

Fixes: 288ace2f57c9 ("netfs: New writeback implementation")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/3317784.1727880350@warthog.procyon.org.uk
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/netfs/write_issue.c | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c
index 3f7e37e50c7d0..9486e54b1e563 100644
--- a/fs/netfs/write_issue.c
+++ b/fs/netfs/write_issue.c
@@ -494,6 +494,30 @@ static int netfs_write_folio(struct netfs_io_request *wreq,
 	return 0;
 }
 
+/*
+ * End the issuing of writes, letting the collector know we're done.
+ */
+static void netfs_end_issue_write(struct netfs_io_request *wreq)
+{
+	bool needs_poke = true;
+
+	smp_wmb(); /* Write subreq lists before ALL_QUEUED. */
+	set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
+
+	for (int s = 0; s < NR_IO_STREAMS; s++) {
+		struct netfs_io_stream *stream = &wreq->io_streams[s];
+
+		if (!stream->active)
+			continue;
+		if (!list_empty(&stream->subrequests))
+			needs_poke = false;
+		netfs_issue_write(wreq, stream);
+	}
+
+	if (needs_poke)
+		netfs_wake_write_collector(wreq, false);
+}
+
 /*
  * Write some of the pending data back to the server
  */
@@ -541,10 +565,7 @@ int netfs_writepages(struct address_space *mapping,
 			break;
 	} while ((folio = writeback_iter(mapping, wbc, folio, &error)));
 
-	for (int s = 0; s < NR_IO_STREAMS; s++)
-		netfs_issue_write(wreq, &wreq->io_streams[s]);
-	smp_wmb(); /* Write lists before ALL_QUEUED. */
-	set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
+	netfs_end_issue_write(wreq);
 
 	mutex_unlock(&ictx->wb_lock);
 
@@ -632,10 +653,7 @@ int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_contr
 	if (writethrough_cache)
 		netfs_write_folio(wreq, wbc, writethrough_cache);
 
-	netfs_issue_write(wreq, &wreq->io_streams[0]);
-	netfs_issue_write(wreq, &wreq->io_streams[1]);
-	smp_wmb(); /* Write lists before ALL_QUEUED. */
-	set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
+	netfs_end_issue_write(wreq);
 
 	mutex_unlock(&ictx->wb_lock);
 
@@ -680,13 +698,7 @@ int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t
 			break;
 	}
 
-	netfs_issue_write(wreq, upload);
-
-	smp_wmb(); /* Write lists before ALL_QUEUED. */
-	set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
-	if (list_empty(&upload->subrequests))
-		netfs_wake_write_collector(wreq, false);
-
+	netfs_end_issue_write(wreq);
 	_leave(" = %d", error);
 	return error;
 }
-- 
2.43.0

[PATCH 6.11 163/558] netfs: Cancel dirty folios that have no storage destination

[Greg Kroah-Hartman]

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

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

From: David Howells <dhowells@redhat.com>

[ Upstream commit 8f246b7c0a1be0882374f2ff831a61f0dbe77678 ]

Kafs wants to be able to cache the contents of directories (and symlinks),
but whilst these are downloaded from the server with the FS.FetchData RPC
op and similar, the same as for regular files, they can't be updated by
FS.StoreData, but rather have special operations (FS.MakeDir, etc.).

Now, rather than redownloading a directory's content after each change made
to that directory, kafs modifies the local blob.  This blob can be saved
out to the cache, and since it's using netfslib, kafs just marks the folios
dirty and lets ->writepages() on the directory take care of it, as for an
regular file.

This is fine as long as there's a cache as although the upload stream is
disabled, there's a cache stream to drive the procedure.  But if the cache
goes away in the meantime, suddenly there's no way do any writes and the
code gets confused, complains "R=%x: No submit" to dmesg and leaves the
dirty folio hanging.

Fix this by just cancelling the store of the folio if neither stream is
active.  (If there's no cache at the time of dirtying, we should just not
mark the folio dirty).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-23-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/netfs/write_issue.c       | 6 +++++-
 include/trace/events/netfs.h | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c
index 9486e54b1e563..b08673d97470c 100644
--- a/fs/netfs/write_issue.c
+++ b/fs/netfs/write_issue.c
@@ -410,13 +410,17 @@ static int netfs_write_folio(struct netfs_io_request *wreq,
 	folio_unlock(folio);
 
 	if (fgroup == NETFS_FOLIO_COPY_TO_CACHE) {
-		if (!fscache_resources_valid(&wreq->cache_resources)) {
+		if (!cache->avail) {
 			trace_netfs_folio(folio, netfs_folio_trace_cancel_copy);
 			netfs_issue_write(wreq, upload);
 			netfs_folio_written_back(folio);
 			return 0;
 		}
 		trace_netfs_folio(folio, netfs_folio_trace_store_copy);
+	} else if (!upload->avail && !cache->avail) {
+		trace_netfs_folio(folio, netfs_folio_trace_cancel_store);
+		netfs_folio_written_back(folio);
+		return 0;
 	} else if (!upload->construct) {
 		trace_netfs_folio(folio, netfs_folio_trace_store);
 	} else {
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 606b4a0f92dae..edcc3b3a3ecf8 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -141,6 +141,7 @@
 	EM(netfs_streaming_cont_filled_page,	"mod-streamw-f+") \
 	/* The rest are for writeback */			\
 	EM(netfs_folio_trace_cancel_copy,	"cancel-copy")	\
+	EM(netfs_folio_trace_cancel_store,	"cancel-store")	\
 	EM(netfs_folio_trace_clear,		"clear")	\
 	EM(netfs_folio_trace_clear_cc,		"clear-cc")	\
 	EM(netfs_folio_trace_clear_g,		"clear-g")	\
-- 
2.43.0