This is a note to let you know that I've just added the patch titled
NFSv4: Fix up mirror allocation
to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsv4-fix-up-mirror-allocation.patch
and it can be found in the queue-4.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 14abcb0bf59a30cf65a74f6c6f53974cd7224bc6 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date: Sat, 19 Aug 2017 10:10:34 -0400
Subject: NFSv4: Fix up mirror allocation
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
commit 14abcb0bf59a30cf65a74f6c6f53974cd7224bc6 upstream.
There are a number of callers of nfs_pageio_complete() that want to
continue using the nfs_pageio_descriptor without needing to call
nfs_pageio_init() again. Examples include nfs_pageio_resend() and
nfs_pageio_cond_complete().
The problem is that nfs_pageio_complete() also calls
nfs_pageio_cleanup_mirroring(), which frees up the array of mirrors.
This can lead to writeback errors, in the next call to
nfs_pageio_setup_mirroring().
Fix by simply moving the allocation of the mirrors to
nfs_pageio_setup_mirroring().
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196709
Reported-by: JianhongYin <yin-jianhong@xxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/pagelist.c | 73 ++++++++++++++++++++++++++++--------------------------
1 file changed, 39 insertions(+), 34 deletions(-)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -712,9 +712,6 @@ void nfs_pageio_init(struct nfs_pageio_d
int io_flags,
gfp_t gfp_flags)
{
- struct nfs_pgio_mirror *new;
- int i;
-
desc->pg_moreio = 0;
desc->pg_inode = inode;
desc->pg_ops = pg_ops;
@@ -730,21 +727,9 @@ void nfs_pageio_init(struct nfs_pageio_d
desc->pg_mirror_count = 1;
desc->pg_mirror_idx = 0;
- if (pg_ops->pg_get_mirror_count) {
- /* until we have a request, we don't have an lseg and no
- * idea how many mirrors there will be */
- new = kcalloc(NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX,
- sizeof(struct nfs_pgio_mirror), gfp_flags);
- desc->pg_mirrors_dynamic = new;
- desc->pg_mirrors = new;
-
- for (i = 0; i < NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX; i++)
- nfs_pageio_mirror_init(&desc->pg_mirrors[i], bsize);
- } else {
- desc->pg_mirrors_dynamic = NULL;
- desc->pg_mirrors = desc->pg_mirrors_static;
- nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
- }
+ desc->pg_mirrors_dynamic = NULL;
+ desc->pg_mirrors = desc->pg_mirrors_static;
+ nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
}
EXPORT_SYMBOL_GPL(nfs_pageio_init);
@@ -863,32 +848,52 @@ static int nfs_generic_pg_pgios(struct n
return ret;
}
+static struct nfs_pgio_mirror *
+nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
+ unsigned int mirror_count)
+{
+ struct nfs_pgio_mirror *ret;
+ unsigned int i;
+
+ kfree(desc->pg_mirrors_dynamic);
+ desc->pg_mirrors_dynamic = NULL;
+ if (mirror_count == 1)
+ return desc->pg_mirrors_static;
+ ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_NOFS);
+ if (ret != NULL) {
+ for (i = 0; i < mirror_count; i++)
+ nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
+ desc->pg_mirrors_dynamic = ret;
+ }
+ return ret;
+}
+
/*
* nfs_pageio_setup_mirroring - determine if mirroring is to be used
* by calling the pg_get_mirror_count op
*/
-static int nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
+static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req)
{
- int mirror_count = 1;
-
- if (!pgio->pg_ops->pg_get_mirror_count)
- return 0;
+ unsigned int mirror_count = 1;
- mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
-
- if (pgio->pg_error < 0)
- return pgio->pg_error;
-
- if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX)
- return -EINVAL;
+ if (pgio->pg_ops->pg_get_mirror_count)
+ mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
+ if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0)
+ return;
- if (WARN_ON_ONCE(!pgio->pg_mirrors_dynamic))
- return -EINVAL;
+ if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
+ pgio->pg_error = -EINVAL;
+ return;
+ }
+ pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count);
+ if (pgio->pg_mirrors == NULL) {
+ pgio->pg_error = -ENOMEM;
+ pgio->pg_mirrors = pgio->pg_mirrors_static;
+ mirror_count = 1;
+ }
pgio->pg_mirror_count = mirror_count;
-
- return 0;
}
/*
Patches currently in stable-queue which might be from trond.myklebust@xxxxxxxxxxxxxxx are
queue-4.13/nfsv4-fix-up-mirror-allocation.patch
queue-4.13/nfs-fix-2-use-after-free-issues-in-the-i-o-code.patch
queue-4.13/nfs-sync-the-correct-byte-range-during-synchronous-writes.patch