[PATCH 4/6] autofs4 - make autofs type usage explicit

From: Ian Kent
Date: Wed Oct 22 2008 - 22:36:13 EST


This patch further improves autofs mount type usage and provides
supplementry explanation of the changes made in the previous patch
"autofs4 - cleanup autofs mount type usage".

Changes introduced in "autofs4 - cleanup autofs mount type usage":

- the type assigned at mount when no type is given is changed
from 0 to AUTOFS_TYPE_INDIRECT. This was done because 0 and
AUTOFS_TYPE_INDIRECT were being treated implicitly as the same
type.

- previously, an offset mount had it's type set to
AUTOFS_TYPE_DIRECT|AUTOFS_TYPE_OFFSET but the mount control
re-implementation needs to be able distinguish all three types.
So this was changed to make the type setting explicit.

- a type AUTOFS_TYPE_ANY was added for use by the re-implementation
when checking if a given path is a mountpoint. It's not really a
type as we use this to ask if a given path is a mountpoint in the
autofs_dev_ioctl_ismountpoint() function.

Changes introduced in this patch:

- macros to set and test the autofs mount types have been added to
improve readability and make the type usage explicit.

- the mount type is used from user space for the mount control
re-implementtion so, for consistency, all the definitions have
been moved to the user space include file include/linux/auto_fs4.h.

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

---

fs/autofs4/autofs_i.h | 2 --
fs/autofs4/dev-ioctl.c | 4 ++--
fs/autofs4/expire.c | 4 ++--
fs/autofs4/inode.c | 14 +++++++-------
fs/autofs4/waitq.c | 8 ++++----
include/linux/auto_fs4.h | 28 ++++++++++++++++++++++++----
6 files changed, 39 insertions(+), 21 deletions(-)


diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index e0f16da..a768031 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -25,8 +25,6 @@
#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
#define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)

-#define AUTOFS_TYPE_TRIGGER (AUTOFS_TYPE_DIRECT|AUTOFS_TYPE_OFFSET)
-
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/time.h>
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 63bfb5d..5a35502 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -510,7 +510,7 @@ static int autofs_dev_ioctl_expire(struct file *fp,
how = param->arg1;
mnt = fp->f_path.mnt;

- if (sbi->type & AUTOFS_TYPE_TRIGGER)
+ if (autofs_type_trigger(sbi->type))
dentry = autofs4_expire_direct(sbi->sb, mnt, sbi, how);
else
dentry = autofs4_expire_indirect(sbi->sb, mnt, sbi, how);
@@ -592,7 +592,7 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp,
param->arg2 = 0;

if (!fp || param->ioctlfd == -1) {
- if (type == AUTOFS_TYPE_ANY) {
+ if (autofs_type_any(type)) {
struct super_block *sb;

err = path_lookup(path, LOOKUP_FOLLOW, &nd);
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 4b6fb3f..e3bd507 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -63,7 +63,7 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);

/* This is an autofs submount, we can't expire it */
- if (sbi->type == AUTOFS_TYPE_INDIRECT)
+ if (autofs_type_indirect(sbi->type))
goto done;

/*
@@ -490,7 +490,7 @@ int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt,
if (arg && get_user(do_now, arg))
return -EFAULT;

- if (sbi->type & AUTOFS_TYPE_TRIGGER)
+ if (autofs_type_trigger(sbi->type))
dentry = autofs4_expire_direct(sb, mnt, sbi, do_now);
else
dentry = autofs4_expire_indirect(sb, mnt, sbi, do_now);
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index 9408507..e014916 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -197,9 +197,9 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
seq_printf(m, ",minproto=%d", sbi->min_proto);
seq_printf(m, ",maxproto=%d", sbi->max_proto);

- if (sbi->type & AUTOFS_TYPE_OFFSET)
+ if (autofs_type_offset(sbi->type))
seq_printf(m, ",offset");
- else if (sbi->type & AUTOFS_TYPE_DIRECT)
+ else if (autofs_type_direct(sbi->type))
seq_printf(m, ",direct");
else
seq_printf(m, ",indirect");
@@ -284,13 +284,13 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
*maxproto = option;
break;
case Opt_indirect:
- *type = AUTOFS_TYPE_INDIRECT;
+ set_autofs_type_indirect(*type);
break;
case Opt_direct:
- *type = AUTOFS_TYPE_DIRECT;
+ set_autofs_type_direct(*type);
break;
case Opt_offset:
- *type = AUTOFS_TYPE_OFFSET;
+ set_autofs_type_offset(*type);
break;
default:
return 1;
@@ -338,7 +338,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
sbi->sb = s;
sbi->version = 0;
sbi->sub_version = 0;
- sbi->type = AUTOFS_TYPE_INDIRECT;
+ set_autofs_type_indirect(sbi->type);
sbi->min_proto = 0;
sbi->max_proto = 0;
mutex_init(&sbi->wq_mutex);
@@ -380,7 +380,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
}

root_inode->i_fop = &autofs4_root_operations;
- root_inode->i_op = sbi->type & AUTOFS_TYPE_TRIGGER ?
+ root_inode->i_op = autofs_type_trigger(sbi->type) ?
&autofs4_direct_root_inode_operations :
&autofs4_indirect_root_inode_operations;

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 4b67c2a..acf88e8 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -337,7 +337,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
* is very similar for indirect mounts except only dentrys
* in the root of the autofs file system may be negative.
*/
- if (sbi->type & AUTOFS_TYPE_TRIGGER)
+ if (autofs_type_trigger(sbi->type))
return -ENOENT;
else if (!IS_ROOT(dentry->d_parent))
return -ENOENT;
@@ -348,7 +348,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
return -ENOMEM;

/* If this is a direct mount request create a dummy name */
- if (IS_ROOT(dentry) && sbi->type & AUTOFS_TYPE_TRIGGER)
+ if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type))
qstr.len = sprintf(name, "%p", dentry);
else {
qstr.len = autofs4_getpath(sbi, dentry, &name);
@@ -406,11 +406,11 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
type = autofs_ptype_expire_multi;
} else {
if (notify == NFY_MOUNT)
- type = (sbi->type & AUTOFS_TYPE_TRIGGER) ?
+ type = autofs_type_trigger(sbi->type) ?
autofs_ptype_missing_direct :
autofs_ptype_missing_indirect;
else
- type = (sbi->type & AUTOFS_TYPE_TRIGGER) ?
+ type = autofs_type_trigger(sbi->type) ?
autofs_ptype_expire_direct :
autofs_ptype_expire_indirect;
}
diff --git a/include/linux/auto_fs4.h b/include/linux/auto_fs4.h
index 2253716..d827765 100644
--- a/include/linux/auto_fs4.h
+++ b/include/linux/auto_fs4.h
@@ -29,10 +29,30 @@
#define AUTOFS_EXP_IMMEDIATE 1
#define AUTOFS_EXP_LEAVES 2

-#define AUTOFS_TYPE_ANY 0x0000
-#define AUTOFS_TYPE_INDIRECT 0x0001
-#define AUTOFS_TYPE_DIRECT 0x0002
-#define AUTOFS_TYPE_OFFSET 0x0004
+#define AUTOFS_TYPE_ANY 0U
+#define AUTOFS_TYPE_INDIRECT 1U
+#define AUTOFS_TYPE_DIRECT 2U
+#define AUTOFS_TYPE_OFFSET 4U
+
+#define set_autofs_type_indirect(type) (type = AUTOFS_TYPE_INDIRECT)
+#define autofs_type_indirect(type) (type == AUTOFS_TYPE_INDIRECT)
+
+#define set_autofs_type_direct(type) (type = AUTOFS_TYPE_DIRECT)
+#define autofs_type_direct(type) (type == AUTOFS_TYPE_DIRECT)
+
+#define set_autofs_type_offset(type) (type = AUTOFS_TYPE_OFFSET)
+#define autofs_type_offset(type) (type == AUTOFS_TYPE_OFFSET)
+
+#define autofs_type_trigger(type) \
+ (type == AUTOFS_TYPE_DIRECT || type == AUTOFS_TYPE_OFFSET)
+
+/*
+ * This isn't really a type as we use it to say "no type set" to
+ * indicate we want to search for "any" mount in the
+ * autofs_dev_ioctl_ismountpoint() device ioctl function.
+ */
+#define set_autofs_type_any(type) (type = AUTOFS_TYPE_ANY)
+#define autofs_type_any(type) (type == AUTOFS_TYPE_ANY)

/* Daemon notification packet types */
enum autofs_notify {

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