user/sven/linux.git/include/linux/sunrpc, branch v6.7.2

Merge tag 'nfs-for-6.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2023-11-08T21:39:16Z

Pull NFS client updates from Trond Myklebust: "Bugfixes: - SUNRPC: - re-probe the target RPC port after an ECONNRESET error - handle allocation errors from rpcb_call_async() - fix a use-after-free condition in rpc_pipefs - fix up various checks for timeouts - NFSv4.1: - Handle NFS4ERR_DELAY errors during session trunking - fix SP4_MACH_CRED protection for pnfs IO - NFSv4: - Ensure that we test all delegations when the server notifies us that it may have revoked some of them Features: - Allow knfsd processes to break out of NFS4ERR_DELAY loops when re-exporting NFSv4.x by setting appropriate values for the 'delay_retrans' module parameter - nfs: Convert nfs_symlink() to use a folio" * tag 'nfs-for-6.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: nfs: Convert nfs_symlink() to use a folio SUNRPC: Fix RPC client cleaned up the freed pipefs dentries NFSv4.1: fix SP4_MACH_CRED protection for pnfs IO SUNRPC: Add an IS_ERR() check back to where it was NFSv4.1: fix handling NFS4ERR_DELAY when testing for session trunking nfs41: drop dependency between flexfiles layout driver and NFSv3 modules NFSv4: fairly test all delegations on a SEQ4_ revocation SUNRPC: SOFTCONN tasks should time out when on the sending list SUNRPC: Force close the socket when a hard error is reported SUNRPC: Don't skip timeout checks in call_connect_status() SUNRPC: ECONNRESET might require a rebind NFSv4/pnfs: Allow layoutget to return EAGAIN for softerr mounts NFSv4: Add a parameter to limit the number of retries after NFS4ERR_DELAY

SUNRPC: Fix RPC client cleaned up the freed pipefs dentries

2023-11-01T19:40:44Z

RPC client pipefs dentries cleanup is in separated rpc_remove_pipedir() workqueue,which takes care about pipefs superblock locking. In some special scenarios, when kernel frees the pipefs sb of the current client and immediately alloctes a new pipefs sb, rpc_remove_pipedir function would misjudge the existence of pipefs sb which is not the one it used to hold. As a result, the rpc_remove_pipedir would clean the released freed pipefs dentries. To fix this issue, rpc_remove_pipedir should check whether the current pipefs sb is consistent with the original pipefs sb. This error can be catched by KASAN: ========================================================= [ 250.497700] BUG: KASAN: slab-use-after-free in dget_parent+0x195/0x200 [ 250.498315] Read of size 4 at addr ffff88800a2ab804 by task kworker/0:18/106503 [ 250.500549] Workqueue: events rpc_free_client_work [ 250.501001] Call Trace: [ 250.502880] kasan_report+0xb6/0xf0 [ 250.503209] ? dget_parent+0x195/0x200 [ 250.503561] dget_parent+0x195/0x200 [ 250.503897] ? __pfx_rpc_clntdir_depopulate+0x10/0x10 [ 250.504384] rpc_rmdir_depopulate+0x1b/0x90 [ 250.504781] rpc_remove_client_dir+0xf5/0x150 [ 250.505195] rpc_free_client_work+0xe4/0x230 [ 250.505598] process_one_work+0x8ee/0x13b0 ... [ 22.039056] Allocated by task 244: [ 22.039390] kasan_save_stack+0x22/0x50 [ 22.039758] kasan_set_track+0x25/0x30 [ 22.040109] __kasan_slab_alloc+0x59/0x70 [ 22.040487] kmem_cache_alloc_lru+0xf0/0x240 [ 22.040889] __d_alloc+0x31/0x8e0 [ 22.041207] d_alloc+0x44/0x1f0 [ 22.041514] __rpc_lookup_create_exclusive+0x11c/0x140 [ 22.041987] rpc_mkdir_populate.constprop.0+0x5f/0x110 [ 22.042459] rpc_create_client_dir+0x34/0x150 [ 22.042874] rpc_setup_pipedir_sb+0x102/0x1c0 [ 22.043284] rpc_client_register+0x136/0x4e0 [ 22.043689] rpc_new_client+0x911/0x1020 [ 22.044057] rpc_create_xprt+0xcb/0x370 [ 22.044417] rpc_create+0x36b/0x6c0 ... [ 22.049524] Freed by task 0: [ 22.049803] kasan_save_stack+0x22/0x50 [ 22.050165] kasan_set_track+0x25/0x30 [ 22.050520] kasan_save_free_info+0x2b/0x50 [ 22.050921] __kasan_slab_free+0x10e/0x1a0 [ 22.051306] kmem_cache_free+0xa5/0x390 [ 22.051667] rcu_core+0x62c/0x1930 [ 22.051995] __do_softirq+0x165/0x52a [ 22.052347] [ 22.052503] Last potentially related work creation: [ 22.052952] kasan_save_stack+0x22/0x50 [ 22.053313] __kasan_record_aux_stack+0x8e/0xa0 [ 22.053739] __call_rcu_common.constprop.0+0x6b/0x8b0 [ 22.054209] dentry_free+0xb2/0x140 [ 22.054540] __dentry_kill+0x3be/0x540 [ 22.054900] shrink_dentry_list+0x199/0x510 [ 22.055293] shrink_dcache_parent+0x190/0x240 [ 22.055703] do_one_tree+0x11/0x40 [ 22.056028] shrink_dcache_for_umount+0x61/0x140 [ 22.056461] generic_shutdown_super+0x70/0x590 [ 22.056879] kill_anon_super+0x3a/0x60 [ 22.057234] rpc_kill_sb+0x121/0x200 Fixes: 0157d021d23a ("SUNRPC: handle RPC client pipefs dentries by network namespace aware routines") Signed-off-by: felix Signed-off-by: Trond Myklebust

NFSD: add rpc_status netlink support

2023-10-16T16:44:09Z

Introduce rpc_status netlink support for NFSD in order to dump pending RPC requests debugging information from userspace. Closes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=366 Tested-by: Jeff Layton Signed-off-by: Lorenzo Bianconi Signed-off-by: Chuck Lever

SUNRPC: change the back-channel queue to lwq

2023-10-16T16:44:08Z

This removes the need to store and update back-links in the list. It also remove the need for the _bh version of spin_lock(). Signed-off-by: NeilBrown Cc: Trond Myklebust Cc: Anna Schumaker Signed-off-by: Chuck Lever

SUNRPC: discard sp_lock

2023-10-16T16:44:08Z

sp_lock is now only used to protect sp_all_threads. This isn't needed as sp_all_threads is only manipulated through svc_set_num_threads(), which is already serialized. Read-acccess only requires rcu_read_lock(). So no more locking is needed. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: change sp_nrthreads to atomic_t

2023-10-16T16:44:07Z

Using an atomic_t avoids the need to take a spinlock (which can soon be removed). Choosing a thread to kill needs to be careful as we cannot set the "die now" bit atomically with the test on the count. Instead we temporarily increase the count. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: use lwq for sp_sockets - renamed to sp_xprts

2023-10-16T16:44:07Z

lwq avoids using back pointers in lists, and uses less locking. This introduces a new spinlock, but the other one will be removed in a future patch. For svc_clean_up_xprts(), we now dequeue the entire queue, walk it to remove and process the xprts that need cleaning up, then re-enqueue the remaining queue. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: only have one thread waking up at a time

2023-10-16T16:44:07Z

Currently if several items of work become available in quick succession, that number of threads (if available) will be woken. By the time some of them wake up another thread that was already cache-warm might have come along and completed the work. Anecdotal evidence suggests as many as 15% of wakes find nothing to do once they get to the point of looking. This patch changes svc_pool_wake_idle_thread() to wake the first thread on the queue but NOT remove it. Subsequent calls will wake the same thread. Once that thread starts it will dequeue itself and after dequeueing some work to do, it will wake the next thread if there is more work ready. This results in a more orderly increase in the number of busy threads. As a bonus, this allows us to reduce locking around the idle queue. svc_pool_wake_idle_thread() no longer needs to take a lock (beyond rcu_read_lock()) as it doesn't manipulate the queue, it just looks at the first item. The thread itself can avoid locking by using the new llist_del_first_this() interface. This will safely remove the thread itself if it is the head. If it isn't the head, it will do nothing. If multiple threads call this concurrently only one will succeed. The others will do nothing, so no corruption can result. If a thread wakes up and finds that it cannot dequeue itself that means either - that it wasn't woken because it was the head of the queue. Maybe the freezer woke it. In that case it can go back to sleep (after trying to freeze of course). - some other thread found there was nothing to do very recently, and placed itself on the head of the queue in front of this thread. It must check again after placing itself there, so it can be deemed to be responsible for any pending work, and this thread can go back to sleep until woken. No code ever tests for busy threads any more. Only each thread itself cares if it is busy. So svc_thread_busy() is no longer needed. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: change service idle list to be an llist

2023-10-16T16:44:05Z

With an llist we don't need to take a lock to add a thread to the list, though we still need a lock to remove it. That will go in the next patch. Unlike double-linked lists, a thread cannot reliably remove itself from the list. Only the first thread can be removed, and that can change asynchronously. So some care is needed. We already check if there is pending work to do, so we are unlikely to add ourselves to the idle list and then want to remove ourselves again. If we DO find something needs to be done after adding ourselves to the list, we simply wake up the first thread on the list. If that was us, we successfully removed ourselves and can continue. If it was some other thread, they will do the work that needs to be done. We can safely sleep until woken. We also remove the test on freezing() from rqst_should_sleep(). Instead we set TASK_FREEZABLE before scheduling. This makes is safe to schedule() when a freeze is pending. As we now loop waiting to be removed from the idle queue, this is a cleaner way to handle freezing. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: discard SP_CONGESTED

2023-10-16T16:44:05Z

We can tell if a pool is congested by checking if the idle list is empty. We don't need a separate flag. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever