Commit 6409a5a6 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd4: clean up downgrading code 



In response to some review comments, get rid of the somewhat obscure
for-loop with bitops, and improve a comment.

Reported-by: default avatarSteve Dickson <steved@redhat.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 71c3bcd7

fs/nfsd/nfs4state.c

+22 −9
Original line number Diff line number Diff line
@@ -3523,16 +3523,29 @@ out: 
	return status;

}



static inline void nfs4_file_downgrade(struct nfs4_ol_stateid *stp, unsigned int to_access)

static inline void nfs4_stateid_downgrade_bit(struct nfs4_ol_stateid *stp, u32 access)

{

	int i;



	for (i = 1; i < 4; i++) {

		if (test_bit(i, &stp->st_access_bmap)

					&& ((i & to_access) != i)) {

			nfs4_file_put_access(stp->st_file, nfs4_access_to_omode(i));

			__clear_bit(i, &stp->st_access_bmap);

	if (!test_bit(access, &stp->st_access_bmap))

		return;

	nfs4_file_put_access(stp->st_file, nfs4_access_to_omode(access));

	__clear_bit(access, &stp->st_access_bmap);

}



static inline void nfs4_stateid_downgrade(struct nfs4_ol_stateid *stp, u32 to_access)

{

	switch (to_access) {

	case NFS4_SHARE_ACCESS_READ:

		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_WRITE);

		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);

		break;

	case NFS4_SHARE_ACCESS_WRITE:

		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_READ);

		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);

		break;

	case NFS4_SHARE_ACCESS_BOTH:

		break;

	default:

		BUG();

	}

}
@@ -3578,7 +3591,7 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp, 
			stp->st_deny_bmap, od->od_share_deny);

		goto out;

	}

	nfs4_file_downgrade(stp, od->od_share_access);

	nfs4_stateid_downgrade(stp, od->od_share_access);



	reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap);

fs/nfsd/state.h

+5 −3
Original line number Diff line number Diff line
@@ -403,9 +403,11 @@ struct nfs4_file { 
	/* One each for O_RDONLY, O_WRONLY, O_RDWR: */

	struct file *		fi_fds[3];

	/*

	 * Each open or lock stateid contributes 1 to either

	 * fi_access[O_RDONLY], fi_access[O_WRONLY], or both, depending

	 * on open or lock mode:

	 * Each open or lock stateid contributes 0-4 to the counts

	 * below depending on which bits are set in st_access_bitmap:

	 *     1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set

	 *   + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set

	 *   + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set.

	 */

	atomic_t		fi_access[2];

	struct file		*fi_deleg_file;