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[PATCH] autofs4: simplify expire tree traversal

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Simplify the expire tree traversal code by using a function from namespace.c
to calculate the next entry in the top down tree traversals carried out during
the expire operation.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ian Kent 2006-03-27 01:14:45 -08:00 committed by Linus Torvalds
parent 1f5f2c3059
commit 1ce12bad85
1 changed files with 40 additions and 62 deletions
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102
fs/autofs4/expire.c
View file

@ -72,6 +72,27 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
return status;
}
/*
* Calculate next entry in top down tree traversal.
* From next_mnt in namespace.c - elegant.
*/
static struct dentry *next_dentry(struct dentry *p, struct dentry *root)
{
struct list_head *next = p->d_subdirs.next;
if (next == &p->d_subdirs) {
while (1) {
if (p == root)
return NULL;
next = p->d_u.d_child.next;
if (next != &p->d_parent->d_subdirs)
break;
p = p->d_parent;
}
}
return list_entry(next, struct dentry, d_u.d_child);
}
/* Check a directory tree of mount points for busyness
* The tree is not busy iff no mountpoints are busy
*/
@ -80,8 +101,7 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
unsigned long timeout,
int do_now)
{
struct dentry *this_parent = top;
struct list_head *next;
struct dentry *p;
DPRINTK("top %p %.*s",
top, (int)top->d_name.len, top->d_name.name);
@ -99,49 +119,28 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
return 1;
spin_lock(&dcache_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
while (next != &this_parent->d_subdirs) {
struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
for (p = top; p; p = next_dentry(p, top)) {
/* Negative dentry - give up */
if (!simple_positive(dentry)) {
next = next->next;
if (!simple_positive(p))
continue;
}
DPRINTK("dentry %p %.*s",
dentry, (int)dentry->d_name.len, dentry->d_name.name);
p, (int) p->d_name.len, p->d_name.name);
if (!simple_empty_nolock(dentry)) {
this_parent = dentry;
goto repeat;
}
dentry = dget(dentry);
p = dget(p);
spin_unlock(&dcache_lock);
if (d_mountpoint(dentry)) {
if (d_mountpoint(p)) {
/* First busy => tree busy */
if (autofs4_mount_busy(mnt, dentry)) {
dput(dentry);
if (autofs4_mount_busy(mnt, p)) {
dput(p);
return 1;
}
}
dput(dentry);
dput(p);
spin_lock(&dcache_lock);
next = next->next;
}
if (this_parent != top) {
next = this_parent->d_u.d_child.next;
this_parent = this_parent->d_parent;
goto resume;
}
spin_unlock(&dcache_lock);
return 0;
}
@ -150,59 +149,38 @@ static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
unsigned long timeout,
int do_now)
{
struct dentry *this_parent = parent;
struct list_head *next;
struct dentry *p;
DPRINTK("parent %p %.*s",
parent, (int)parent->d_name.len, parent->d_name.name);
spin_lock(&dcache_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
while (next != &this_parent->d_subdirs) {
struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
for (p = parent; p; p = next_dentry(p, parent)) {
/* Negative dentry - give up */
if (!simple_positive(dentry)) {
next = next->next;
if (!simple_positive(p))
continue;
}
DPRINTK("dentry %p %.*s",
dentry, (int)dentry->d_name.len, dentry->d_name.name);
p, (int) p->d_name.len, p->d_name.name);
if (!list_empty(&dentry->d_subdirs)) {
this_parent = dentry;
goto repeat;
}
dentry = dget(dentry);
p = dget(p);
spin_unlock(&dcache_lock);
if (d_mountpoint(dentry)) {
if (d_mountpoint(p)) {
/* Can we expire this guy */
if (!autofs4_can_expire(dentry, timeout, do_now))
if (!autofs4_can_expire(p, timeout, do_now))
goto cont;
/* Can we umount this guy */
if (!autofs4_mount_busy(mnt, dentry))
return dentry;
if (!autofs4_mount_busy(mnt, p))
return p;
}
cont:
dput(dentry);
dput(p);
spin_lock(&dcache_lock);
next = next->next;
}
if (this_parent != parent) {
next = this_parent->d_u.d_child.next;
this_parent = this_parent->d_parent;
goto resume;
}
spin_unlock(&dcache_lock);
return NULL;
}