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netfs: Fix looping in wait functions

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netfs_wait_for_request() and netfs_wait_for_pause() can loop forever if
netfs_collect_in_app() returns 2, indicating that it wants to repeat
because the ALL_QUEUED flag isn't yet set and there are no subreqs left
that haven't been collected.

The problem is that, unless collection is offloaded (OFFLOAD_COLLECTION),
we have to return to the application thread to continue and eventually set
ALL_QUEUED after pausing to deal with a retry - but we never get there.

Fix this by inserting checks for the IN_PROGRESS and PAUSE flags as
appropriate before cycling round - and add cond_resched() for good measure.

Fixes: 2b1424cd13 ("netfs: Fix wait/wake to be consistent about the waitqueue used")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250701163852.2171681-5-dhowells@redhat.com
Tested-by: Steve French <sfrench@samba.org>
Reviewed-by: Paulo Alcantara <pc@manguebit.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
David Howells
2025-07-01 22:37:13 +02:00
committed by Christian Brauner
parent 1a6d45fec3
commit 09623e3a14
1 changed files with 11 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/netfs/misc.c
+11 -4
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@@ -430,8 +430,8 @@ static int netfs_collect_in_app(struct netfs_io_request *rreq,
/*
* Wait for a request to complete, successfully or otherwise.
*/
static ssize_t netfs_wait_for_request(struct netfs_io_request *rreq,
bool (*collector)(struct netfs_io_request *rreq))
static ssize_t netfs_wait_for_in_progress(struct netfs_io_request *rreq,
bool (*collector)(struct netfs_io_request *rreq))
{
DEFINE_WAIT(myself);
ssize_t ret;
@@ -447,6 +447,9 @@ static ssize_t netfs_wait_for_request(struct netfs_io_request *rreq,
case 1:
goto all_collected;
case 2:
if (!netfs_check_rreq_in_progress(rreq))
break;
cond_resched();
continue;
}
}
@@ -485,12 +488,12 @@ all_collected:
ssize_t netfs_wait_for_read(struct netfs_io_request *rreq)
{
return netfs_wait_for_request(rreq, netfs_read_collection);
return netfs_wait_for_in_progress(rreq, netfs_read_collection);
}
ssize_t netfs_wait_for_write(struct netfs_io_request *rreq)
{
return netfs_wait_for_request(rreq, netfs_write_collection);
return netfs_wait_for_in_progress(rreq, netfs_write_collection);
}
/*
@@ -514,6 +517,10 @@ static void netfs_wait_for_pause(struct netfs_io_request *rreq,
case 1:
goto all_collected;
case 2:
if (!netfs_check_rreq_in_progress(rreq) ||
!test_bit(NETFS_RREQ_PAUSE, &rreq->flags))
break;
cond_resched();
continue;
}
}