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 <[email protected]>
Cc: [email protected] # 4.0+
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pagelist.c | 73 +++++++++++++++++++++++++++++--------------------------
1 file changed, 39 insertions(+), 34 deletions(-)
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 548ebc7256ff..1c7e625824dc 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -685,9 +685,6 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
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;
@@ -703,21 +700,9 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
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);
@@ -836,32 +821,52 @@ static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
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;
+ unsigned int mirror_count = 1;
- if (!pgio->pg_ops->pg_get_mirror_count)
- return 0;
-
- 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;
}
/*
--
2.13.5
Looks good to me.
Reviewed-by: Weston Andros Adamson <[email protected]>
-dros
> On Aug 20, 2017, at 10:32 AM, Trond Myklebust =
<[email protected]> wrote:
>=20
> 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().
>=20
> 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().
>=20
> Fix by simply moving the allocation of the mirrors to
> nfs_pageio_setup_mirroring().
>=20
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D196709
> Reported-by: JianhongYin <[email protected]>
> Cc: [email protected] # 4.0+
> Signed-off-by: Trond Myklebust <[email protected]>
> ---
> fs/nfs/pagelist.c | 73 =
+++++++++++++++++++++++++++++--------------------------
> 1 file changed, 39 insertions(+), 34 deletions(-)
>=20
> diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
> index 548ebc7256ff..1c7e625824dc 100644
> --- a/fs/nfs/pagelist.c
> +++ b/fs/nfs/pagelist.c
> @@ -685,9 +685,6 @@ void nfs_pageio_init(struct nfs_pageio_descriptor =
*desc,
> int io_flags,
> gfp_t gfp_flags)
> {
> - struct nfs_pgio_mirror *new;
> - int i;
> -
> desc->pg_moreio =3D 0;
> desc->pg_inode =3D inode;
> desc->pg_ops =3D pg_ops;
> @@ -703,21 +700,9 @@ void nfs_pageio_init(struct nfs_pageio_descriptor =
*desc,
> desc->pg_mirror_count =3D 1;
> desc->pg_mirror_idx =3D 0;
>=20
> - 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 =3D kcalloc(NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX,
> - sizeof(struct nfs_pgio_mirror), =
gfp_flags);
> - desc->pg_mirrors_dynamic =3D new;
> - desc->pg_mirrors =3D new;
> -
> - for (i =3D 0; i < NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX; i++)
> - nfs_pageio_mirror_init(&desc->pg_mirrors[i], =
bsize);
> - } else {
> - desc->pg_mirrors_dynamic =3D NULL;
> - desc->pg_mirrors =3D desc->pg_mirrors_static;
> - nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
> - }
> + desc->pg_mirrors_dynamic =3D NULL;
> + desc->pg_mirrors =3D desc->pg_mirrors_static;
> + nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
> }
> EXPORT_SYMBOL_GPL(nfs_pageio_init);
>=20
> @@ -836,32 +821,52 @@ static int nfs_generic_pg_pgios(struct =
nfs_pageio_descriptor *desc)
> return ret;
> }
>=20
> +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 =3D NULL;
> + if (mirror_count =3D=3D 1)
> + return desc->pg_mirrors_static;
> + ret =3D kmalloc_array(mirror_count, sizeof(*ret), GFP_NOFS);
> + if (ret !=3D NULL) {
> + for (i =3D 0; i < mirror_count; i++)
> + nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
> + desc->pg_mirrors_dynamic =3D 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 =3D 1;
> + unsigned int mirror_count =3D 1;
>=20
> - if (!pgio->pg_ops->pg_get_mirror_count)
> - return 0;
> -
> - mirror_count =3D 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 =3D pgio->pg_ops->pg_get_mirror_count(pgio, =
req);
> + if (mirror_count =3D=3D pgio->pg_mirror_count || pgio->pg_error =
< 0)
> + return;
>=20
> - if (WARN_ON_ONCE(!pgio->pg_mirrors_dynamic))
> - return -EINVAL;
> + if (!mirror_count || mirror_count > =
NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
> + pgio->pg_error =3D -EINVAL;
> + return;
> + }
>=20
> + pgio->pg_mirrors =3D nfs_pageio_alloc_mirrors(pgio, =
mirror_count);
> + if (pgio->pg_mirrors =3D=3D NULL) {
> + pgio->pg_error =3D -ENOMEM;
> + pgio->pg_mirrors =3D pgio->pg_mirrors_static;
> + mirror_count =3D 1;
> + }
> pgio->pg_mirror_count =3D mirror_count;
> -
> - return 0;
> }
>=20
> /*
> --=20
> 2.13.5
>=20
> --
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