Commit 117aff74 authored by Al Viro's avatar Al Viro
Browse files

Fix autofs_expire() 



mnt should remain the same for all iterations through the list;
as it is, if we have a busy mount, mnt follows into it and isn't
restored for the next iteration.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 24b6f16e

fs/autofs/dirhash.c

+18 −16
Original line number Diff line number Diff line
@@ -39,10 +39,12 @@ struct autofs_dir_ent *autofs_expire(struct super_block *sb, 
{

	struct autofs_dirhash *dh = &sbi->dirhash;

	struct autofs_dir_ent *ent;

	struct dentry *dentry;

	unsigned long timeout = sbi->exp_timeout;



	while (1) {

		struct path path;

		int umount_ok;



		if ( list_empty(&dh->expiry_head) || sbi->catatonic )

			return NULL;	/* No entries */

		/* We keep the list sorted by last_usage and want old stuff */
@@ -57,17 +59,17 @@ struct autofs_dir_ent *autofs_expire(struct super_block *sb, 
			return ent; /* Symlinks are always expirable */



		/* Get the dentry for the autofs subdirectory */

		dentry = ent->dentry;

		path.dentry = ent->dentry;



		if ( !dentry ) {

		if (!path.dentry) {

			/* Should only happen in catatonic mode */

			printk("autofs: dentry == NULL but inode range is directory, entry %s\n", ent->name);

			autofs_delete_usage(ent);

			continue;

		}



		if ( !dentry->d_inode ) {

			dput(dentry);

		if (!path.dentry->d_inode) {

			dput(path.dentry);

			printk("autofs: negative dentry on expiry queue: %s\n",

			       ent->name);

			autofs_delete_usage(ent);
@@ -76,29 +78,29 @@ struct autofs_dir_ent *autofs_expire(struct super_block *sb, 


		/* Make sure entry is mounted and unused; note that dentry will

		   point to the mounted-on-top root. */

		if (!S_ISDIR(dentry->d_inode->i_mode)||!d_mountpoint(dentry)) {

		if (!S_ISDIR(path.dentry->d_inode->i_mode) ||

		    !d_mountpoint(path.dentry)) {

			DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));

			continue;

		}

		mntget(mnt);

		dget(dentry);

		if (!follow_down(&mnt, &dentry)) {

			dput(dentry);

			mntput(mnt);

		path.mnt = mnt;

		path_get(&path);

		if (!follow_down(&path.mnt, &path.dentry)) {

			path_put(&path);

			DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name));

			continue;

		}

		while (d_mountpoint(dentry) && follow_down(&mnt, &dentry))

		while (d_mountpoint(path.dentry) &&

		       follow_down(&path.mnt, &path.dentry))

			;

		dput(dentry);

		umount_ok = may_umount(path.mnt);

		path_put(&path);



		if ( may_umount(mnt) ) {

			mntput(mnt);

		if (umount_ok) {

			DPRINTK(("autofs: signaling expire on %s\n", ent->name));

			return ent; /* Expirable! */

		}

		DPRINTK(("autofs: didn't expire due to may_umount: %s\n", ent->name));

		mntput(mnt);

	}

	return NULL;		/* No expirable entries */

}