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Commit b44061d0 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd: reorganize nfsd_create 



There's some odd logic in nfsd_create() that allows it to be called with
the parent directory either locked or unlocked.  The only already-locked
caller is NFSv2's nfsd_proc_create().  It's less confusing to split out
the unlocked case into a separate function which the NFSv2 code can call
directly.

Also fix some comments while we're here.

Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent e75b23f9

fs/nfsd/nfsproc.c

+2 −2
Original line number Diff line number Diff line
@@ -359,8 +359,8 @@ nfsd_proc_create(struct svc_rqst *rqstp, struct nfsd_createargs *argp, 
	nfserr = 0;

	if (!inode) {

		/* File doesn't exist. Create it and set attrs */

		nfserr = nfsd_create(rqstp, dirfhp, argp->name, argp->len,

					attr, type, rdev, newfhp);

		nfserr = nfsd_create_locked(rqstp, dirfhp, argp->name,

					argp->len, attr, type, rdev, newfhp);

	} else if (type == S_IFREG) {

		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",

			argp->name, attr->ia_valid, (long) attr->ia_size);

fs/nfsd/vfs.c

+56 −53
Original line number Diff line number Diff line
@@ -1135,16 +1135,9 @@ nfsd_check_ignore_resizing(struct iattr *iap) 
		iap->ia_valid &= ~ATTR_SIZE;

}



/*

 * Create a file (regular, directory, device, fifo); UNIX sockets 

 * not yet implemented.

 * If the response fh has been verified, the parent directory should

 * already be locked. Note that the parent directory is left locked.

 *

 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp

 */

/* The parent directory should already be locked: */

__be32

nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,

nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,

		char *fname, int flen, struct iattr *iap,

		int type, dev_t rdev, struct svc_fh *resfhp)

{
@@ -1154,51 +1147,16 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	__be32		err2;

	int		host_err;



	err = nfserr_exist;

	if (isdotent(fname, flen))

		goto out;



	/*

	 * Even though it is a create, first let's see if we are even allowed

	 * to peek inside the parent

	 */

	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);

	if (err)

		goto out;



	dentry = fhp->fh_dentry;

	dirp = d_inode(dentry);



	/*

	 * Check whether the response file handle has been verified yet.

	 * If it has, the parent directory should already be locked.

	 */

	if (!resfhp->fh_dentry) {

		host_err = fh_want_write(fhp);

		if (host_err)

			goto out_nfserr;



		/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */

		fh_lock_nested(fhp, I_MUTEX_PARENT);

		dchild = lookup_one_len(fname, dentry, flen);

		host_err = PTR_ERR(dchild);

		if (IS_ERR(dchild))

			goto out_nfserr;

		err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);

		if (err)

			goto out;

	} else {

		/* called from nfsd_proc_create */

	dchild = dget(resfhp->fh_dentry);

	if (!fhp->fh_locked) {

			/* not actually possible */

			printk(KERN_ERR

				"nfsd_create: parent %pd2 not locked!\n",

		WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",

				dentry);

		err = nfserr_io;

		goto out;

	}

	}

	/*

	 * Make sure the child dentry is still negative ...

	 */
@@ -1225,9 +1183,6 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 
		goto out;

	}



	/*

	 * Get the dir op function pointer.

	 */

	err = 0;

	host_err = 0;

	switch (type) {
@@ -1254,7 +1209,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	/*

	 * nfsd_create_setattr already committed the child.  Transactional

	 * filesystems had a chance to commit changes for both parent and

	 * child * simultaneously making the following commit_metadata a

	 * child simultaneously making the following commit_metadata a

	 * noop.

	 */

	err2 = nfserrno(commit_metadata(fhp));
@@ -1275,6 +1230,54 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 
	goto out;

}



/*

 * Create a filesystem object (regular, directory, special).

 * Note that the parent directory is left locked.

 *

 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp

 */

__be32

nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,

		char *fname, int flen, struct iattr *iap,

		int type, dev_t rdev, struct svc_fh *resfhp)

{

	struct dentry	*dentry, *dchild = NULL;

	struct inode	*dirp;

	__be32		err;

	int		host_err;



	if (isdotent(fname, flen))

		return nfserr_exist;



	/*

	 * Even though it is a create, first let's see if we are even allowed

	 * to peek inside the parent

	 */

	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);

	if (err)

		return err;



	dentry = fhp->fh_dentry;

	dirp = d_inode(dentry);



	host_err = fh_want_write(fhp);

	if (host_err)

		return nfserrno(host_err);



	fh_lock_nested(fhp, I_MUTEX_PARENT);

	dchild = lookup_one_len(fname, dentry, flen);

	host_err = PTR_ERR(dchild);

	if (IS_ERR(dchild))

		return nfserrno(host_err);

	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);

	if (err) {

		dput(dchild);

		return err;

	}

	return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,

					rdev, resfhp);

}



#ifdef CONFIG_NFSD_V3



/*

fs/nfsd/vfs.h

+3 −0
Original line number Diff line number Diff line
@@ -59,6 +59,9 @@ __be32 nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *, 
__be32		nfsd4_clone_file_range(struct file *, u64, struct file *,

			u64, u64);

#endif /* CONFIG_NFSD_V4 */

__be32		nfsd_create_locked(struct svc_rqst *, struct svc_fh *,

				char *name, int len, struct iattr *attrs,

				int type, dev_t rdev, struct svc_fh *res);

__be32		nfsd_create(struct svc_rqst *, struct svc_fh *,

				char *name, int len, struct iattr *attrs,

				int type, dev_t rdev, struct svc_fh *res);