From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 7c9d845f0612e5bcd23456a2ec43be8ac43458f1 ]
In nfs4_callback_devicenotify(), if we don't find a matching entry for the deviceid, we're left with a pointer to 'struct nfs_server' that actually points to the list of super blocks associated with our struct nfs_client. Furthermore, even if we have a valid pointer, nothing pins the super block, and so the struct nfs_server could end up getting freed while we're using it.
Since all we want is a pointer to the struct pnfs_layoutdriver_type, let's skip all the iteration over super blocks, and just use APIs to find the layout driver directly.
Reported-by: Xiaomeng Tong xiam0nd.tong@gmail.com Fixes: 1be5683b03a7 ("pnfs: CB_NOTIFY_DEVICEID") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/callback_proc.c | 27 +++++++++------------------ fs/nfs/pnfs.c | 11 +++++++++++ fs/nfs/pnfs.h | 2 ++ 3 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index f2bc5b5b764b..a30dd35ec1c2 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -358,12 +358,11 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp, struct cb_process_state *cps) { struct cb_devicenotifyargs *args = argp; + const struct pnfs_layoutdriver_type *ld = NULL; uint32_t i; __be32 res = 0; - struct nfs_client *clp = cps->clp; - struct nfs_server *server = NULL;
- if (!clp) { + if (!cps->clp) { res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION); goto out; } @@ -371,23 +370,15 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp, for (i = 0; i < args->ndevs; i++) { struct cb_devicenotifyitem *dev = &args->devs[i];
- if (!server || - server->pnfs_curr_ld->id != dev->cbd_layout_type) { - rcu_read_lock(); - list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) - if (server->pnfs_curr_ld && - server->pnfs_curr_ld->id == dev->cbd_layout_type) { - rcu_read_unlock(); - goto found; - } - rcu_read_unlock(); - continue; + if (!ld || ld->id != dev->cbd_layout_type) { + pnfs_put_layoutdriver(ld); + ld = pnfs_find_layoutdriver(dev->cbd_layout_type); + if (!ld) + continue; } - - found: - nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id); + nfs4_delete_deviceid(ld, cps->clp, &dev->cbd_dev_id); } - + pnfs_put_layoutdriver(ld); out: kfree(args->devs); return res; diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 7c9090a28e5c..7ddd003ab8b1 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -92,6 +92,17 @@ find_pnfs_driver(u32 id) return local; }
+const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id) +{ + return find_pnfs_driver(id); +} + +void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld) +{ + if (ld) + module_put(ld->owner); +} + void unset_pnfs_layoutdriver(struct nfs_server *nfss) { diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index a0f6ff094b3a..5a54cf8ac6f3 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -238,6 +238,8 @@ struct pnfs_devicelist {
extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *); extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *); +extern const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id); +extern void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld);
/* nfs4proc.c */ extern size_t max_response_pages(struct nfs_server *server);