6.12-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 8f8df955f078e1a023ee55161935000a67651f38 ]
If the file is sillyrenamed, and slated for delete on close, it is possible for a server reboot to triggeer an open reclaim, with can again race with the application call to close(). When that happens, the call to put_nfs_open_context() can trigger a synchronous delegreturn call which deadlocks because it is not marked as privileged.
Instead, ensure that the call to nfs4_inode_return_delegation_on_close() catches the delegreturn, and schedules it asynchronously.
Reported-by: Li Lingfeng lilingfeng3@huawei.com Fixes: adb4b42d19ae ("Return the delegation when deleting sillyrenamed files") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Anna Schumaker anna.schumaker@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/delegation.c | 37 +++++++++++++++++++++++++++++++++++++ fs/nfs/delegation.h | 1 + fs/nfs/nfs4proc.c | 3 +++ 3 files changed, 41 insertions(+)
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 035ba52742a50..4db912f562305 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -780,6 +780,43 @@ int nfs4_inode_return_delegation(struct inode *inode) return 0; }
+/** + * nfs4_inode_set_return_delegation_on_close - asynchronously return a delegation + * @inode: inode to process + * + * This routine is called to request that the delegation be returned as soon + * as the file is closed. If the file is already closed, the delegation is + * immediately returned. + */ +void nfs4_inode_set_return_delegation_on_close(struct inode *inode) +{ + struct nfs_delegation *delegation; + struct nfs_delegation *ret = NULL; + + if (!inode) + return; + rcu_read_lock(); + delegation = nfs4_get_valid_delegation(inode); + if (!delegation) + goto out; + spin_lock(&delegation->lock); + if (!delegation->inode) + goto out_unlock; + if (list_empty(&NFS_I(inode)->open_files) && + !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { + /* Refcount matched in nfs_end_delegation_return() */ + ret = nfs_get_delegation(delegation); + } else + set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); +out_unlock: + spin_unlock(&delegation->lock); + if (ret) + nfs_clear_verifier_delegated(inode); +out: + rcu_read_unlock(); + nfs_end_delegation_return(inode, ret, 0); +} + /** * nfs4_inode_return_delegation_on_close - asynchronously return a delegation * @inode: inode to process diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h index 71524d34ed207..8ff5ab9c5c256 100644 --- a/fs/nfs/delegation.h +++ b/fs/nfs/delegation.h @@ -49,6 +49,7 @@ void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred, unsigned long pagemod_limit, u32 deleg_type); int nfs4_inode_return_delegation(struct inode *inode); void nfs4_inode_return_delegation_on_close(struct inode *inode); +void nfs4_inode_set_return_delegation_on_close(struct inode *inode); int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid); void nfs_inode_evict_delegation(struct inode *inode);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 405f17e6e0b45..e7bc99c69743c 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3898,8 +3898,11 @@ nfs4_atomic_open(struct inode *dir, struct nfs_open_context *ctx,
static void nfs4_close_context(struct nfs_open_context *ctx, int is_sync) { + struct dentry *dentry = ctx->dentry; if (ctx->state == NULL) return; + if (dentry->d_flags & DCACHE_NFSFS_RENAMED) + nfs4_inode_set_return_delegation_on_close(d_inode(dentry)); if (is_sync) nfs4_close_sync(ctx->state, _nfs4_ctx_to_openmode(ctx)); else