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Commit 468640e3 authored by Sage Weil's avatar Sage Weil
Browse files

ceph: fix ceph_lookup_open intent usage 



We weren't properly calling lookup_instantiate_filp when setting up the
lookup intent, which could lead to file leakage on errors.  So:

 - use separate helper for the hidden snapdir translation, immediately
   following the mds request
 - use ceph_finish_lookup for the final dentry/return value dance in the
   exit path
 - lookup_instantiate_filp on success

Reported-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: default avatarYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent 9bae113a

fs/ceph/dir.c

+20 −11
Original line number Diff line number Diff line
@@ -482,17 +482,9 @@ static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int origin) 
}



/*

 * Process result of a lookup/open request.

 *

 * Mainly, make sure we return the final req->r_dentry (if it already

 * existed) in place of the original VFS-provided dentry when they

 * differ.

 *

 * Gracefully handle the case where the MDS replies with -ENOENT and

 * no trace (which it may do, at its discretion, e.g., if it doesn't

 * care to issue a lease on the negative dentry).

 * Handle lookups for the hidden .snap directory.

 */

struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,

int ceph_handle_snapdir(struct ceph_mds_request *req,

			struct dentry *dentry, int err)

{

	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
@@ -510,7 +502,23 @@ struct dentry *ceph_finish_lookup(struct ceph_mds_request *req, 
		d_add(dentry, inode);

		err = 0;

	}

	return err;

}



/*

 * Figure out final result of a lookup/open request.

 *

 * Mainly, make sure we return the final req->r_dentry (if it already

 * existed) in place of the original VFS-provided dentry when they

 * differ.

 *

 * Gracefully handle the case where the MDS replies with -ENOENT and

 * no trace (which it may do, at its discretion, e.g., if it doesn't

 * care to issue a lease on the negative dentry).

 */

struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,

				  struct dentry *dentry, int err)

{

	if (err == -ENOENT) {

		/* no trace? */

		err = 0;
@@ -605,6 +613,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry, 
	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);

	req->r_locked_dir = dir;

	err = ceph_mdsc_do_request(mdsc, NULL, req);

	err = ceph_handle_snapdir(req, dentry, err);

	dentry = ceph_finish_lookup(req, dentry, err);

	ceph_mdsc_put_request(req);  /* will dput(dentry) */

	dout("lookup result=%p\n", dentry);

fs/ceph/file.c

+15 −8
Original line number Diff line number Diff line
@@ -223,8 +223,9 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry, 
{

	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);

	struct ceph_mds_client *mdsc = fsc->mdsc;

	struct file *file = nd->intent.open.file;

	struct file *file;

	struct ceph_mds_request *req;

	struct dentry *ret;

	int err;

	int flags = nd->intent.open.flags - 1;  /* silly vfs! */
@@ -245,15 +246,21 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry, 
	err = ceph_mdsc_do_request(mdsc,

				   (flags & (O_CREAT|O_TRUNC)) ? dir : NULL,

				   req);

	dentry = ceph_finish_lookup(req, dentry, err);

	if (!err && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)

	err = ceph_handle_snapdir(req, dentry, err);

	if (err)

		goto out;

	if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)

		err = ceph_handle_notrace_create(dir, dentry);

	if (!err)

		err = ceph_init_file(req->r_dentry->d_inode, file,

				     req->r_fmode);

	if (err)

		goto out;

	file = lookup_instantiate_filp(nd, req->r_dentry, ceph_open);

	if (IS_ERR(file))

		err = PTR_ERR(file);

out:

	ret = ceph_finish_lookup(req, dentry, err);

	ceph_mdsc_put_request(req);

	dout("ceph_lookup_open result=%p\n", dentry);

	return dentry;

	dout("ceph_lookup_open result=%p\n", ret);

	return ret;

}



int ceph_release(struct inode *inode, struct file *file)

fs/ceph/super.h

+2 −0
Original line number Diff line number Diff line
@@ -791,6 +791,8 @@ extern const struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops, 
	ceph_snapdir_dentry_ops;



extern int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry);

extern int ceph_handle_snapdir(struct ceph_mds_request *req,

			       struct dentry *dentry, int err);

extern struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,

					 struct dentry *dentry, int err);