NFSv4/flexfiles: Fix invalid deref in FF_LAYOUT_DEVID_NODE()

If the attempt to instantiate the mirror's layout DS pointer failed,
then that pointer may hold a value of type ERR_PTR(), so we need
to check that before we dereference it.

Fixes: 65990d1afb ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2019-02-26 11:19:46 -05:00
parent 1a3466aed3
commit 108bb4afd3

View File

@ -132,16 +132,6 @@ FF_LAYOUT_LSEG(struct pnfs_layout_segment *lseg)
generic_hdr);
}
static inline struct nfs4_deviceid_node *
FF_LAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg, u32 idx)
{
if (idx >= FF_LAYOUT_LSEG(lseg)->mirror_array_cnt ||
FF_LAYOUT_LSEG(lseg)->mirror_array[idx] == NULL ||
FF_LAYOUT_LSEG(lseg)->mirror_array[idx]->mirror_ds == NULL)
return NULL;
return &FF_LAYOUT_LSEG(lseg)->mirror_array[idx]->mirror_ds->id_node;
}
static inline struct nfs4_ff_layout_ds *
FF_LAYOUT_MIRROR_DS(struct nfs4_deviceid_node *node)
{
@ -151,9 +141,25 @@ FF_LAYOUT_MIRROR_DS(struct nfs4_deviceid_node *node)
static inline struct nfs4_ff_layout_mirror *
FF_LAYOUT_COMP(struct pnfs_layout_segment *lseg, u32 idx)
{
if (idx >= FF_LAYOUT_LSEG(lseg)->mirror_array_cnt)
return NULL;
return FF_LAYOUT_LSEG(lseg)->mirror_array[idx];
struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
if (idx < fls->mirror_array_cnt)
return fls->mirror_array[idx];
return NULL;
}
static inline struct nfs4_deviceid_node *
FF_LAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg, u32 idx)
{
struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, idx);
if (mirror != NULL) {
struct nfs4_ff_layout_ds *mirror_ds = mirror->mirror_ds;
if (!IS_ERR_OR_NULL(mirror_ds))
return &mirror_ds->id_node;
}
return NULL;
}
static inline u32