[RFC:PATCH 4/4] autofs4 - add new packet type for v5 communications

From: Ian Kent
Date: Fri Feb 17 2006 - 02:00:24 EST


This patch define a new autofs packet for autofs v5 and updates
the waitq.c functions to handle the additional packet type.

Signed-off-by: Ian Kent <raven@xxxxxxxxxx>


--- linux-2.6.16-rc2-mm1/include/linux/auto_fs4.h.v5-packet-proto 2006-02-09 20:11:00.000000000 +0800
+++ linux-2.6.16-rc2-mm1/include/linux/auto_fs4.h 2006-02-09 20:38:30.000000000 +0800
@@ -19,18 +19,37 @@
#undef AUTOFS_MIN_PROTO_VERSION
#undef AUTOFS_MAX_PROTO_VERSION

-#define AUTOFS_PROTO_VERSION 4
+#define AUTOFS_PROTO_VERSION 5
#define AUTOFS_MIN_PROTO_VERSION 3
-#define AUTOFS_MAX_PROTO_VERSION 4
+#define AUTOFS_MAX_PROTO_VERSION 5

-#define AUTOFS_PROTO_SUBVERSION 10
+#define AUTOFS_PROTO_SUBVERSION 0

/* Mask for expire behaviour */
#define AUTOFS_EXP_IMMEDIATE 1
#define AUTOFS_EXP_LEAVES 2

-/* New message type */
-#define autofs_ptype_expire_multi 2 /* Expire entry (umount request) */
+/* Daemon notification packet types */
+enum autofs_notify {
+ NFY_NONE,
+ NFY_MOUNT,
+ NFY_EXPIRE
+};
+
+/* Kernel protocol version 4 packet types */
+
+/* Expire entry (umount request) */
+#define autofs_ptype_expire_multi 2
+
+/* Kernel protocol version 5 packet types */
+
+/* Indirect mount missing and expire requests. */
+#define autofs_ptype_missing_indirect 3
+#define autofs_ptype_expire_indirect 4
+
+/* Direct mount missing and expire requests */
+#define autofs_ptype_missing_direct 5
+#define autofs_ptype_expire_direct 6

/* v4 multi expire (via pipe) */
struct autofs_packet_expire_multi {
@@ -40,14 +59,36 @@ struct autofs_packet_expire_multi {
char name[NAME_MAX+1];
};

+/* autofs v5 common packet struct */
+struct autofs_v5_packet {
+ struct autofs_packet_hdr hdr;
+ autofs_wqt_t wait_queue_token;
+ __u32 dev;
+ __u64 ino;
+ uid_t uid;
+ gid_t gid;
+ pid_t pid;
+ pid_t tgid;
+ int len;
+ char name[NAME_MAX+1];
+};
+
+typedef struct autofs_v5_packet autofs_packet_missing_indirect_t;
+typedef struct autofs_v5_packet autofs_packet_expire_indirect_t;
+typedef struct autofs_v5_packet autofs_packet_missing_direct_t;
+typedef struct autofs_v5_packet autofs_packet_expire_direct_t;
+
union autofs_packet_union {
struct autofs_packet_hdr hdr;
struct autofs_packet_missing missing;
struct autofs_packet_expire expire;
struct autofs_packet_expire_multi expire_multi;
+ struct autofs_v5_packet v5_packet;
};

#define AUTOFS_IOC_EXPIRE_MULTI _IOW(0x93,0x66,int)
+#define AUTOFS_IOC_EXPIRE_INDIRECT AUTOFS_IOC_EXPIRE_MULTI
+#define AUTOFS_IOC_EXPIRE_DIRECT AUTOFS_IOC_EXPIRE_MULTI
#define AUTOFS_IOC_PROTOSUBVER _IOR(0x93,0x67,int)
#define AUTOFS_IOC_ASKREGHOST _IOR(0x93,0x68,int)
#define AUTOFS_IOC_TOGGLEREGHOST _IOR(0x93,0x69,int)
--- linux-2.6.16-rc2-mm1/fs/autofs4/autofs_i.h.v5-packet-proto 2006-02-09 20:33:15.000000000 +0800
+++ linux-2.6.16-rc2-mm1/fs/autofs4/autofs_i.h 2006-02-09 20:38:30.000000000 +0800
@@ -77,6 +77,12 @@ struct autofs_wait_queue {
int hash;
int len;
char *name;
+ u32 dev;
+ u64 ino;
+ uid_t uid;
+ gid_t gid;
+ pid_t pid;
+ pid_t tgid;
/* This is for status reporting upon return */
int status;
atomic_t notified;
@@ -179,13 +185,6 @@ struct autofs_info *autofs4_init_ino(str

/* Queue management functions */

-enum autofs_notify
-{
- NFY_NONE,
- NFY_MOUNT,
- NFY_EXPIRE
-};
-
int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
void autofs4_catatonic_mode(struct autofs_sb_info *);
@@ -203,6 +202,16 @@ static inline int autofs4_follow_mount(s
return res;
}

+static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
+{
+ return new_encode_dev(sbi->sb->s_dev);
+}
+
+static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
+{
+ return sbi->sb->s_root->d_inode->i_ino;
+}
+
static inline int simple_positive(struct dentry *dentry)
{
return dentry->d_inode && !d_unhashed(dentry);
--- linux-2.6.16-rc2-mm1/fs/autofs4/waitq.c.v5-packet-proto 2006-02-09 20:10:11.000000000 +0800
+++ linux-2.6.16-rc2-mm1/fs/autofs4/waitq.c 2006-02-09 20:38:53.000000000 +0800
@@ -3,7 +3,7 @@
* linux/fs/autofs/waitq.c
*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
- * Copyright 2001-2003 Ian Kent <raven@xxxxxxxxxx>
+ * Copyright 2001-2006 Ian Kent <raven@xxxxxxxxxx>
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
@@ -97,7 +97,10 @@ static void autofs4_notify_daemon(struct

pkt.hdr.proto_version = sbi->version;
pkt.hdr.type = type;
- if (type == autofs_ptype_missing) {
+ switch (type) {
+ /* Kernel protocol v4 missing and expire packets */
+ case autofs_ptype_missing:
+ {
struct autofs_packet_missing *mp = &pkt.missing;

pktsz = sizeof(*mp);
@@ -106,7 +109,10 @@ static void autofs4_notify_daemon(struct
mp->len = wq->len;
memcpy(mp->name, wq->name, wq->len);
mp->name[wq->len] = '\0';
- } else if (type == autofs_ptype_expire_multi) {
+ break;
+ }
+ case autofs_ptype_expire_multi:
+ {
struct autofs_packet_expire_multi *ep = &pkt.expire_multi;

pktsz = sizeof(*ep);
@@ -115,7 +121,34 @@ static void autofs4_notify_daemon(struct
ep->len = wq->len;
memcpy(ep->name, wq->name, wq->len);
ep->name[wq->len] = '\0';
- } else {
+ break;
+ }
+ /*
+ * Kernel protocol v5 packet for handling indirect and direct
+ * mount missing and expire requests
+ */
+ case autofs_ptype_missing_indirect:
+ case autofs_ptype_expire_indirect:
+ case autofs_ptype_missing_direct:
+ case autofs_ptype_expire_direct:
+ {
+ struct autofs_v5_packet *packet = &pkt.v5_packet;
+
+ pktsz = sizeof(*packet);
+
+ packet->wait_queue_token = wq->wait_queue_token;
+ packet->len = wq->len;
+ memcpy(packet->name, wq->name, wq->len);
+ packet->name[wq->len] = '\0';
+ packet->dev = wq->dev;
+ packet->ino = wq->ino;
+ packet->uid = wq->uid;
+ packet->gid = wq->gid;
+ packet->pid = wq->pid;
+ packet->tgid = wq->tgid;
+ break;
+ }
+ default:
printk("autofs4_notify_daemon: bad type %d!\n", type);
return;
}
@@ -161,7 +194,9 @@ int autofs4_wait(struct autofs_sb_info *
{
struct autofs_wait_queue *wq;
char *name;
- int len, status;
+ unsigned int len = 0;
+ unsigned int hash = 0;
+ int status;

/* In catatonic mode, we don't wait for nobody */
if (sbi->catatonic)
@@ -171,11 +206,17 @@ int autofs4_wait(struct autofs_sb_info *
if (!name)
return -ENOMEM;

- len = autofs4_getpath(sbi, dentry, &name);
- if (!len) {
- kfree(name);
- return -ENOENT;
+ /* If this is a direct mount request create a dummy name */
+ if (IS_ROOT(dentry) && (sbi->type & AUTOFS_TYP_DIRECT))
+ len = sprintf(name, "%p", dentry);
+ else {
+ len = autofs4_getpath(sbi, dentry, &name);
+ if (!len) {
+ kfree(name);
+ return -ENOENT;
+ }
}
+ hash = full_name_hash(name, len);

if (mutex_lock_interruptible(&sbi->wq_mutex)) {
kfree(name);
@@ -211,9 +252,15 @@ int autofs4_wait(struct autofs_sb_info *
wq->next = sbi->queues;
sbi->queues = wq;
init_waitqueue_head(&wq->queue);
- wq->hash = dentry->d_name.hash;
+ wq->hash = hash;
wq->name = name;
wq->len = len;
+ wq->dev = autofs4_get_dev(sbi);
+ wq->ino = autofs4_get_ino(sbi);
+ wq->uid = current->uid;
+ wq->gid = current->gid;
+ wq->pid = current->pid;
+ wq->tgid = current->tgid;
wq->status = -EINTR; /* Status return if interrupted */
atomic_set(&wq->wait_ctr, 2);
atomic_set(&wq->notified, 1);
@@ -227,8 +274,23 @@ int autofs4_wait(struct autofs_sb_info *
}

if (notify != NFY_NONE && atomic_dec_and_test(&wq->notified)) {
- int type = (notify == NFY_MOUNT ?
- autofs_ptype_missing : autofs_ptype_expire_multi);
+ int type;
+
+ if (sbi->version < 5) {
+ if (notify == NFY_MOUNT)
+ type = autofs_ptype_missing;
+ else
+ type = autofs_ptype_expire_multi;
+ } else {
+ if (notify == NFY_MOUNT)
+ type = (sbi->type & AUTOFS_TYP_DIRECT) ?
+ autofs_ptype_missing_direct :
+ autofs_ptype_missing_indirect;
+ else
+ type = (sbi->type & AUTOFS_TYP_DIRECT) ?
+ autofs_ptype_expire_direct :
+ autofs_ptype_expire_indirect;
+ }

DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
-
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