[PATCH kernel-4.19 1/3] NFS: Add a helper nfs_client_for_each_server()
From: Trond Myklebust <trond.myklebust@hammerspace.com> mainline inclusion from mainline-v5.7-rc1 commit 3c9e502b59fbd243cfac7cc6c875e432d285102a category: bugfix bugzilla: 182252 CVE: NA ----------------------------------------------- Add a helper nfs_client_for_each_server() to iterate through all the filesystems that are attached to a struct nfs_client, and apply a function to all the active ones. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/nfs/internal.h | 4 +++- fs/nfs/super.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+), 1 deletion(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index cc07189a501fa..c3c0b40f163f1 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -417,7 +417,9 @@ extern int __init register_nfs_fs(void); extern void __exit unregister_nfs_fs(void); extern bool nfs_sb_active(struct super_block *sb); extern void nfs_sb_deactive(struct super_block *sb); - +extern int nfs_client_for_each_server(struct nfs_client *clp, + int (*fn)(struct nfs_server *, void *), + void *data); /* io.c */ extern void nfs_start_io_read(struct inode *inode); extern void nfs_end_io_read(struct inode *inode); diff --git a/fs/nfs/super.c b/fs/nfs/super.c index fe107348aabe6..48bcdcf4d039e 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -429,6 +429,41 @@ void nfs_sb_deactive(struct super_block *sb) } EXPORT_SYMBOL_GPL(nfs_sb_deactive); +static int __nfs_list_for_each_server(struct list_head *head, + int (*fn)(struct nfs_server *, void *), + void *data) +{ + struct nfs_server *server, *last = NULL; + int ret = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(server, head, client_link) { + if (!nfs_sb_active(server->super)) + continue; + rcu_read_unlock(); + if (last) + nfs_sb_deactive(last->super); + last = server; + ret = fn(server, data); + if (ret) + goto out; + rcu_read_lock(); + } + rcu_read_unlock(); +out: + if (last) + nfs_sb_deactive(last->super); + return ret; +} + +int nfs_client_for_each_server(struct nfs_client *clp, + int (*fn)(struct nfs_server *, void *), + void *data) +{ + return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data); +} +EXPORT_SYMBOL_GPL(nfs_client_for_each_server); + /* * Deliver file system statistics to userspace */ -- 2.25.1
From: Trond Myklebust <trond.myklebust@hammerspace.com> mainline inclusion from mainline-v5.7-rc1 commit af3b61bf61319a4808f310d04ef3ff28c224cb1e category: bugfix bugzilla: 182252 CVE: NA ----------------------------------------------- Convert it to use the nfs_client_for_each_server() helper, and make it more efficient by skipping delegations for inodes we know are in the process of being freed. Also improve the efficiency of the cursor by skipping delegations that are being freed. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/nfs/delegation.c | 129 +++++++++++++++++++++----------------------- 1 file changed, 60 insertions(+), 69 deletions(-) diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 8517f0d5cf26b..98811a0774509 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -486,21 +486,11 @@ static bool nfs_delegation_need_return(struct nfs_delegation *delegation) return ret; } -/** - * nfs_client_return_marked_delegations - return previously marked delegations - * @clp: nfs_client to process - * - * Note that this function is designed to be called by the state - * manager thread. For this reason, it cannot flush the dirty data, - * since that could deadlock in case of a state recovery error. - * - * Returns zero on success, or a negative errno value. - */ -int nfs_client_return_marked_delegations(struct nfs_client *clp) +static int nfs_server_return_marked_delegations(struct nfs_server *server, + void __always_unused *data) { struct nfs_delegation *delegation; struct nfs_delegation *prev; - struct nfs_server *server; struct inode *inode; struct inode *place_holder = NULL; struct nfs_delegation *place_holder_deleg = NULL; @@ -510,78 +500,79 @@ int nfs_client_return_marked_delegations(struct nfs_client *clp) /* * To avoid quadratic looping we hold a reference * to an inode place_holder. Each time we restart, we - * list nfs_servers from the server of that inode, and - * delegation in the server from the delegations of that - * inode. + * list delegation in the server from the delegations + * of that inode. * prev is an RCU-protected pointer to a delegation which * wasn't marked for return and might be a good choice for * the next place_holder. */ - rcu_read_lock(); prev = NULL; + delegation = NULL; + rcu_read_lock(); if (place_holder) - server = NFS_SERVER(place_holder); - else - server = list_entry_rcu(clp->cl_superblocks.next, - struct nfs_server, client_link); - list_for_each_entry_from_rcu(server, &clp->cl_superblocks, client_link) { - delegation = NULL; - if (place_holder && server == NFS_SERVER(place_holder)) - delegation = rcu_dereference(NFS_I(place_holder)->delegation); - if (!delegation || delegation != place_holder_deleg) - delegation = list_entry_rcu(server->delegations.next, - struct nfs_delegation, super_list); - list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { - struct inode *to_put = NULL; - - if (!nfs_delegation_need_return(delegation)) { + delegation = rcu_dereference(NFS_I(place_holder)->delegation); + if (!delegation || delegation != place_holder_deleg) + delegation = list_entry_rcu(server->delegations.next, + struct nfs_delegation, super_list); + list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { + struct inode *to_put = NULL; + + if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) + continue; + if (!nfs_delegation_need_return(delegation)) { + if (nfs4_is_valid_delegation(delegation, 0)) prev = delegation; - continue; - } - if (!nfs_sb_active(server->super)) - break; /* continue in outer loop */ - - if (prev) { - struct inode *tmp; + continue; + } - tmp = nfs_delegation_grab_inode(prev); - if (tmp) { - to_put = place_holder; - place_holder = tmp; - place_holder_deleg = prev; - } + if (prev) { + struct inode *tmp = nfs_delegation_grab_inode(prev); + if (tmp) { + to_put = place_holder; + place_holder = tmp; + place_holder_deleg = prev; } + } - inode = nfs_delegation_grab_inode(delegation); - if (inode == NULL) { - rcu_read_unlock(); - if (to_put) - iput(to_put); - nfs_sb_deactive(server->super); - goto restart; - } - delegation = nfs_start_delegation_return_locked(NFS_I(inode)); + inode = nfs_delegation_grab_inode(delegation); + if (inode == NULL) { rcu_read_unlock(); + iput(to_put); + goto restart; + } + delegation = nfs_start_delegation_return_locked(NFS_I(inode)); + rcu_read_unlock(); - if (to_put) - iput(to_put); + iput(to_put); - err = nfs_end_delegation_return(inode, delegation, 0); - iput(inode); - nfs_sb_deactive(server->super); - cond_resched(); - if (!err) - goto restart; - set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); - if (place_holder) - iput(place_holder); - return err; - } + err = nfs_end_delegation_return(inode, delegation, 0); + iput(inode); + cond_resched(); + if (!err) + goto restart; + set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); + goto out; } rcu_read_unlock(); - if (place_holder) - iput(place_holder); - return 0; +out: + iput(place_holder); + return err; +} + +/** + * nfs_client_return_marked_delegations - return previously marked delegations + * @clp: nfs_client to process + * + * Note that this function is designed to be called by the state + * manager thread. For this reason, it cannot flush the dirty data, + * since that could deadlock in case of a state recovery error. + * + * Returns zero on success, or a negative errno value. + */ +int nfs_client_return_marked_delegations(struct nfs_client *clp) +{ + return nfs_client_for_each_server(clp, + nfs_server_return_marked_delegations, NULL); } /** -- 2.25.1
From: Trond Myklebust <trond.myklebust@hammerspace.com> mainline inclusion from mainline-v5.7-rc4 commit 9c07b75b80eeff714420fb6a4c880b284e529d0f category: bugfix bugzilla: 182252 CVE: NA ----------------------------------------------- The struct nfs_server gets put on the cl_superblocks list before the server->super field has been initialised, in which case the call to nfs_sb_active() will Oops. Add a check to ensure that we skip such a list entry. Fixes: 3c9e502b59fb ("NFS: Add a helper nfs_client_for_each_server()") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/nfs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 48bcdcf4d039e..a05e1eb2c3fd1 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -438,7 +438,7 @@ static int __nfs_list_for_each_server(struct list_head *head, rcu_read_lock(); list_for_each_entry_rcu(server, head, client_link) { - if (!nfs_sb_active(server->super)) + if (!(server->super && nfs_sb_active(server->super))) continue; rcu_read_unlock(); if (last) -- 2.25.1
-
Yang Yingliang