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Commit 06effdbb authored by Bernd Schubert's avatar Bernd Schubert Committed by Theodore Ts'o
Browse files

nfsd: vfs_llseek() with 32 or 64 bit offsets (hashes) 



Use 32-bit or 64-bit llseek() hashes for directory offsets depending on
the NFS version. NFSv2 gets 32-bit hashes only.

NOTE: This patch got rather complex as Christoph asked to set the
filp->f_mode flag in the open call or immediatly after dentry_open()
in nfsd_open() to avoid races.
Personally I still do not see a reason for that and in my opinion
FMODE_32BITHASH/FMODE_64BITHASH flags could be set nfsd_readdir(), as it
follows directly after nfsd_open() without a chance of races.

Signed-off-by: default avatarBernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Acked-by: default avatarJ. Bruce <Fields&lt;bfields@redhat.com>
parent 999448a8

fs/nfsd/vfs.c

+13 −2
Original line number Diff line number Diff line
@@ -796,9 +796,15 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 
			    flags, current_cred());

	if (IS_ERR(*filp))

		host_err = PTR_ERR(*filp);

	else

	else {

		host_err = ima_file_check(*filp, may_flags);



		if (may_flags & NFSD_MAY_64BIT_COOKIE)

			(*filp)->f_mode |= FMODE_64BITHASH;

		else

			(*filp)->f_mode |= FMODE_32BITHASH;

	}



out_nfserr:

	err = nfserrno(host_err);

out:
@@ -2022,8 +2028,13 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 
	__be32		err;

	struct file	*file;

	loff_t		offset = *offsetp;

	int             may_flags = NFSD_MAY_READ;



	/* NFSv2 only supports 32 bit cookies */

	if (rqstp->rq_vers > 2)

		may_flags |= NFSD_MAY_64BIT_COOKIE;



	err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);

	err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);

	if (err)

		goto out;

fs/nfsd/vfs.h

+2 −0
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ 
#define NFSD_MAY_BYPASS_GSS		0x400

#define NFSD_MAY_READ_IF_EXEC		0x800



#define NFSD_MAY_64BIT_COOKIE		0x1000 /* 64 bit readdir cookies for >= NFSv3 */



#define NFSD_MAY_CREATE		(NFSD_MAY_EXEC|NFSD_MAY_WRITE)

#define NFSD_MAY_REMOVE		(NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)