Commit 0622753b authored by Dave Hansen's avatar Dave Hansen Committed by Al Viro
Browse files

[PATCH] r/o bind mounts: elevate write count for rmdir and unlink. 



Elevate the write count during the vfs_rmdir() and vfs_unlink().

[AV: merged rmdir and unlink parts, added missing pieces in nfsd]

Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Acked-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 49e0d02c

fs/namei.c

+9 −0
Original line number Diff line number Diff line
@@ -2190,7 +2190,12 @@ static long do_rmdir(int dfd, const char __user *pathname) 
	error = PTR_ERR(dentry);

	if (IS_ERR(dentry))

		goto exit2;

	error = mnt_want_write(nd.path.mnt);

	if (error)

		goto exit3;

	error = vfs_rmdir(nd.path.dentry->d_inode, dentry);

	mnt_drop_write(nd.path.mnt);

exit3:

	dput(dentry);

exit2:

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
@@ -2271,7 +2276,11 @@ static long do_unlinkat(int dfd, const char __user *pathname) 
		inode = dentry->d_inode;

		if (inode)

			atomic_inc(&inode->i_count);

		error = mnt_want_write(nd.path.mnt);

		if (error)

			goto exit2;

		error = vfs_unlink(nd.path.dentry->d_inode, dentry);

		mnt_drop_write(nd.path.mnt);

	exit2:

		dput(dentry);

	}

fs/nfsd/nfs4recover.c

+11 −1
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
#include <linux/scatterlist.h>

#include <linux/crypto.h>

#include <linux/sched.h>

#include <linux/mount.h>



#define NFSDDBG_FACILITY                NFSDDBG_PROC
@@ -313,12 +314,17 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp) 
	if (!rec_dir_init || !clp->cl_firststate)

		return;



	status = mnt_want_write(rec_dir.path.mnt);

	if (status)

		goto out;

	clp->cl_firststate = 0;

	nfs4_save_user(&uid, &gid);

	status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);

	nfs4_reset_user(uid, gid);

	if (status == 0)

		nfsd4_sync_rec_dir();

	mnt_drop_write(rec_dir.path.mnt);

out:

	if (status)

		printk("NFSD: Failed to remove expired client state directory"

				" %.*s\n", HEXDIR_LEN, clp->cl_recdir);
@@ -347,13 +353,17 @@ nfsd4_recdir_purge_old(void) { 


	if (!rec_dir_init)

		return;

	status = mnt_want_write(rec_dir.path.mnt);

	if (status)

		goto out;

	status = nfsd4_list_rec_dir(rec_dir.path.dentry, purge_old);

	if (status == 0)

		nfsd4_sync_rec_dir();

	mnt_drop_write(rec_dir.path.mnt);

out:

	if (status)

		printk("nfsd4: failed to purge old clients from recovery"

			" directory %s\n", rec_dir.path.dentry->d_name.name);

	return;

}



static int

fs/nfsd/vfs.c

+7 −1
Original line number Diff line number Diff line
@@ -1750,6 +1750,10 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 
	if (!type)

		type = rdentry->d_inode->i_mode & S_IFMT;



	host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);

	if (host_err)

		goto out_nfserr;



	if (type != S_IFDIR) { /* It's UNLINK */

#ifdef MSNFS

		if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
@@ -1765,10 +1769,12 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 
	dput(rdentry);



	if (host_err)

		goto out_nfserr;

		goto out_drop;

	if (EX_ISSYNC(fhp->fh_export))

		host_err = nfsd_sync_dir(dentry);



out_drop:

	mnt_drop_write(fhp->fh_export->ex_path.mnt);

out_nfserr:

	err = nfserrno(host_err);

out:

ipc/mqueue.c

+4 −1
Original line number Diff line number Diff line
@@ -742,8 +742,11 @@ asmlinkage long sys_mq_unlink(const char __user *u_name) 
	inode = dentry->d_inode;

	if (inode)

		atomic_inc(&inode->i_count);



	err = mnt_want_write(mqueue_mnt);

	if (err)

		goto out_err;

	err = vfs_unlink(dentry->d_parent->d_inode, dentry);

	mnt_drop_write(mqueue_mnt);

out_err:

	dput(dentry);