From aa07c713ecfc0522916f3cd57ac628ea6127c0ec Mon Sep 17 00:00:00 2001 From: Kinglong Mee Date: Fri, 18 Apr 2014 20:49:04 +0800 Subject: [PATCH] NFSD: Call ->set_acl with a NULL ACL structure if no entries After setting ACL for directory, I got two problems that caused by the cached zero-length default posix acl. This patch make sure nfsd4_set_nfs4_acl calls ->set_acl with a NULL ACL structure if there are no entries. Thanks for Christoph Hellwig's advice. First problem: ............ hang ........... Second problem: [ 1610.167668] ------------[ cut here ]------------ [ 1610.168320] kernel BUG at /root/nfs/linux/fs/nfsd/nfs4acl.c:239! [ 1610.168320] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 1610.168320] Modules linked in: nfsv4(OE) nfs(OE) nfsd(OE) rpcsec_gss_krb5 fscache ip6t_rpfilter ip6t_REJECT cfg80211 xt_conntrack rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw auth_rpcgss nfs_acl snd_intel8x0 ppdev lockd snd_ac97_codec ac97_bus snd_pcm snd_timer e1000 pcspkr parport_pc snd parport serio_raw joydev i2c_piix4 sunrpc(OE) microcode soundcore i2c_core ata_generic pata_acpi [last unloaded: nfsd] [ 1610.168320] CPU: 0 PID: 27397 Comm: nfsd Tainted: G OE 3.15.0-rc1+ #15 [ 1610.168320] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 1610.168320] task: ffff88005ab653d0 ti: ffff88005a944000 task.ti: ffff88005a944000 [ 1610.168320] RIP: 0010:[] [] _posix_to_nfsv4_one+0x3cd/0x3d0 [nfsd] [ 1610.168320] RSP: 0018:ffff88005a945b00 EFLAGS: 00010293 [ 1610.168320] RAX: 0000000000000001 RBX: ffff88006700bac0 RCX: 0000000000000000 [ 1610.168320] RDX: 0000000000000000 RSI: ffff880067c83f00 RDI: ffff880068233300 [ 1610.168320] RBP: ffff88005a945b48 R08: ffffffff81c64830 R09: 0000000000000000 [ 1610.168320] R10: ffff88004ea85be0 R11: 000000000000f475 R12: ffff880068233300 [ 1610.168320] R13: 0000000000000003 R14: 0000000000000002 R15: ffff880068233300 [ 1610.168320] FS: 0000000000000000(0000) GS:ffff880077800000(0000) knlGS:0000000000000000 [ 1610.168320] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1610.168320] CR2: 00007f5bcbd3b0b9 CR3: 0000000001c0f000 CR4: 00000000000006f0 [ 1610.168320] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1610.168320] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1610.168320] Stack: [ 1610.168320] ffffffff00000000 0000000b67c83500 000000076700bac0 0000000000000000 [ 1610.168320] ffff88006700bac0 ffff880068233300 ffff88005a945c08 0000000000000002 [ 1610.168320] 0000000000000000 ffff88005a945b88 ffffffffa034e2d5 000000065a945b68 [ 1610.168320] Call Trace: [ 1610.168320] [] nfsd4_get_nfs4_acl+0x95/0x150 [nfsd] [ 1610.168320] [] nfsd4_encode_fattr+0x646/0x1e70 [nfsd] [ 1610.168320] [] ? kmemleak_alloc+0x4e/0xb0 [ 1610.168320] [] ? nfsd_setuser_and_check_port+0x52/0x80 [nfsd] [ 1610.168320] [] ? selinux_cred_prepare+0x1b/0x30 [ 1610.168320] [] nfsd4_encode_getattr+0x5a/0x60 [nfsd] [ 1610.168320] [] nfsd4_encode_operation+0x67/0x110 [nfsd] [ 1610.168320] [] nfsd4_proc_compound+0x21d/0x810 [nfsd] [ 1610.168320] [] nfsd_dispatch+0xbb/0x200 [nfsd] [ 1610.168320] [] svc_process_common+0x46d/0x6d0 [sunrpc] [ 1610.168320] [] svc_process+0x103/0x170 [sunrpc] [ 1610.168320] [] nfsd+0xbf/0x130 [nfsd] [ 1610.168320] [] ? nfsd_destroy+0x80/0x80 [nfsd] [ 1610.168320] [] kthread+0xd2/0xf0 [ 1610.168320] [] ? insert_kthread_work+0x40/0x40 [ 1610.168320] [] ret_from_fork+0x7c/0xb0 [ 1610.168320] [] ? insert_kthread_work+0x40/0x40 [ 1610.168320] Code: 78 02 e9 e7 fc ff ff 31 c0 31 d2 31 c9 66 89 45 ce 41 8b 04 24 66 89 55 d0 66 89 4d d2 48 8d 04 80 49 8d 5c 84 04 e9 37 fd ff ff <0f> 0b 90 0f 1f 44 00 00 55 8b 56 08 c7 07 00 00 00 00 8b 46 0c [ 1610.168320] RIP [] _posix_to_nfsv4_one+0x3cd/0x3d0 [nfsd] [ 1610.168320] RSP [ 1610.257313] ---[ end trace 838254e3e352285b ]--- Signed-off-by: Kinglong Mee Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4acl.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c index 6f3f392d48af..b6f46013dddf 100644 --- a/fs/nfsd/nfs4acl.c +++ b/fs/nfsd/nfs4acl.c @@ -402,8 +402,10 @@ sort_pacl(struct posix_acl *pacl) * by uid/gid. */ int i, j; - if (pacl->a_count <= 4) - return; /* no users or groups */ + /* no users or groups */ + if (!pacl || pacl->a_count <= 4) + return; + i = 1; while (pacl->a_entries[i].e_tag == ACL_USER) i++; @@ -530,13 +532,12 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) /* * ACLs with no ACEs are treated differently in the inheritable - * and effective cases: when there are no inheritable ACEs, we - * set a zero-length default posix acl: + * and effective cases: when there are no inheritable ACEs, + * calls ->set_acl with a NULL ACL structure. */ - if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) { - pacl = posix_acl_alloc(0, GFP_KERNEL); - return pacl ? pacl : ERR_PTR(-ENOMEM); - } + if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) + return NULL; + /* * When there are no effective ACEs, the following will end * up setting a 3-element effective posix ACL with all -- 2.20.1