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path: root/fs/autofs4/inode.c
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Diffstat (limited to 'fs/autofs4/inode.c')
-rw-r--r--fs/autofs4/inode.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index 4bb14cc6804..0a3c05d1016 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -16,6 +16,7 @@
#include <linux/pagemap.h>
#include <linux/parser.h>
#include <linux/bitops.h>
+#include <linux/smp_lock.h>
#include "autofs_i.h"
#include <linux/module.h>
@@ -76,6 +77,66 @@ void autofs4_free_ino(struct autofs_info *ino)
kfree(ino);
}
+/*
+ * Deal with the infamous "Busy inodes after umount ..." message.
+ *
+ * Clean up the dentry tree. This happens with autofs if the user
+ * space program goes away due to a SIGKILL, SIGSEGV etc.
+ */
+static void autofs4_force_release(struct autofs_sb_info *sbi)
+{
+ struct dentry *this_parent = sbi->root;
+ struct list_head *next;
+
+ 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_child);
+
+ /* Negative dentry - don`t care */
+ if (!simple_positive(dentry)) {
+ next = next->next;
+ continue;
+ }
+
+ if (!list_empty(&dentry->d_subdirs)) {
+ this_parent = dentry;
+ goto repeat;
+ }
+
+ next = next->next;
+ spin_unlock(&dcache_lock);
+
+ DPRINTK("dentry %p %.*s",
+ dentry, (int)dentry->d_name.len, dentry->d_name.name);
+
+ dput(dentry);
+ spin_lock(&dcache_lock);
+ }
+
+ if (this_parent != sbi->root) {
+ struct dentry *dentry = this_parent;
+
+ next = this_parent->d_child.next;
+ this_parent = this_parent->d_parent;
+ spin_unlock(&dcache_lock);
+ DPRINTK("parent dentry %p %.*s",
+ dentry, (int)dentry->d_name.len, dentry->d_name.name);
+ dput(dentry);
+ spin_lock(&dcache_lock);
+ goto resume;
+ }
+ spin_unlock(&dcache_lock);
+
+ dput(sbi->root);
+ sbi->root = NULL;
+ shrink_dcache_sb(sbi->sb);
+
+ return;
+}
+
static void autofs4_put_super(struct super_block *sb)
{
struct autofs_sb_info *sbi = autofs4_sbi(sb);
@@ -85,6 +146,10 @@ static void autofs4_put_super(struct super_block *sb)
if ( !sbi->catatonic )
autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
+ /* Clean up and release dangling references */
+ if (sbi)
+ autofs4_force_release(sbi);
+
kfree(sbi);
DPRINTK("shutting down");
@@ -199,6 +264,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
s->s_fs_info = sbi;
sbi->magic = AUTOFS_SBI_MAGIC;
+ sbi->root = NULL;
sbi->catatonic = 0;
sbi->exp_timeout = 0;
sbi->oz_pgrp = process_group(current);
@@ -267,6 +333,13 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
sbi->pipe = pipe;
/*
+ * Take a reference to the root dentry so we get a chance to
+ * clean up the dentry tree on umount.
+ * See autofs4_force_release.
+ */
+ sbi->root = dget(root);
+
+ /*
* Success! Install the root dentry now to indicate completion.
*/
s->s_root = root;