vfs.c 47.2 KB
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#define MSNFS	/* HACK HACK */
/*
 * linux/fs/nfsd/vfs.c
 *
 * File operations used by nfsd. Some of these have been ripped from
 * other parts of the kernel because they weren't exported, others
 * are partial duplicates with added or changed functionality.
 *
 * Note that several functions dget() the dentry upon which they want
 * to act, most notably those that create directory entries. Response
 * dentry's are dput()'d if necessary in the release callback.
 * So if you notice code paths that apparently fail to dput() the
 * dentry, don't worry--they have been taken care of.
 *
 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
 */

#include <linux/string.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/major.h>
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#include <linux/splice.h>
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#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/in.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/delay.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#ifdef CONFIG_NFSD_V3
#include <linux/nfs3.h>
#include <linux/nfsd/xdr3.h>
#endif /* CONFIG_NFSD_V3 */
#include <linux/nfsd/nfsfh.h>
#include <linux/quotaops.h>
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#include <linux/fsnotify.h>
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#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
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#ifdef CONFIG_NFSD_V4
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#include <linux/nfs4.h>
#include <linux/nfs4_acl.h>
#include <linux/nfsd_idmap.h>
#include <linux/security.h>
#endif /* CONFIG_NFSD_V4 */
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#include <linux/jhash.h>
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#include <asm/uaccess.h>

#define NFSDDBG_FACILITY		NFSDDBG_FILEOP


/* We must ignore files (but only files) which might have mandatory
 * locks on them because there is no way to know if the accesser has
 * the lock.
 */
#define IS_ISMNDLK(i)	(S_ISREG((i)->i_mode) && MANDATORY_LOCK(i))

/*
 * This is a cache of readahead params that help us choose the proper
 * readahead strategy. Initially, we set all readahead parameters to 0
 * and let the VFS handle things.
 * If you increase the number of cached files very much, you'll need to
 * add a hash table here.
 */
struct raparms {
	struct raparms		*p_next;
	unsigned int		p_count;
	ino_t			p_ino;
	dev_t			p_dev;
	int			p_set;
	struct file_ra_state	p_ra;
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	unsigned int		p_hindex;
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};

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struct raparm_hbucket {
	struct raparms		*pb_head;
	spinlock_t		pb_lock;
} ____cacheline_aligned_in_smp;

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static struct raparms *		raparml;
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#define RAPARM_HASH_BITS	4
#define RAPARM_HASH_SIZE	(1<<RAPARM_HASH_BITS)
#define RAPARM_HASH_MASK	(RAPARM_HASH_SIZE-1)
static struct raparm_hbucket	raparm_hash[RAPARM_HASH_SIZE];
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/* 
 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
 * a mount point.
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 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
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 *  or nfs_ok having possibly changed *dpp and *expp
 */
int
nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 
		        struct svc_export **expp)
{
	struct svc_export *exp = *expp, *exp2 = NULL;
	struct dentry *dentry = *dpp;
	struct vfsmount *mnt = mntget(exp->ex_mnt);
	struct dentry *mounts = dget(dentry);
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	int err = 0;
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	while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));

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	exp2 = rqst_exp_get_by_name(rqstp, mnt, mounts);
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	if (IS_ERR(exp2)) {
		err = PTR_ERR(exp2);
		dput(mounts);
		mntput(mnt);
		goto out;
	}
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	if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
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		/* successfully crossed mount point */
		exp_put(exp);
		*expp = exp2;
		dput(dentry);
		*dpp = mounts;
	} else {
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		exp_put(exp2);
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		dput(mounts);
	}
	mntput(mnt);
out:
	return err;
}

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__be32
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nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
		   const char *name, int len,
		   struct svc_export **exp_ret, struct dentry **dentry_ret)
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{
	struct svc_export	*exp;
	struct dentry		*dparent;
	struct dentry		*dentry;
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	__be32			err;
	int			host_err;
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	dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);

	/* Obtain dentry and export. */
	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
	if (err)
		return err;

	dparent = fhp->fh_dentry;
	exp  = fhp->fh_export;
	exp_get(exp);

	/* Lookup the name, but don't follow links */
	if (isdotent(name, len)) {
		if (len==1)
			dentry = dget(dparent);
		else if (dparent != exp->ex_dentry) {
			dentry = dget_parent(dparent);
		} else  if (!EX_NOHIDE(exp))
			dentry = dget(dparent); /* .. == . just like at / */
		else {
			/* checking mountpoint crossing is very different when stepping up */
			struct svc_export *exp2 = NULL;
			struct dentry *dp;
			struct vfsmount *mnt = mntget(exp->ex_mnt);
			dentry = dget(dparent);
			while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
				;
			dp = dget_parent(dentry);
			dput(dentry);
			dentry = dp;

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			exp2 = rqst_exp_parent(rqstp, mnt, dentry);
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			if (PTR_ERR(exp2) == -ENOENT) {
				dput(dentry);
				dentry = dget(dparent);
			} else if (IS_ERR(exp2)) {
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				host_err = PTR_ERR(exp2);
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				dput(dentry);
				mntput(mnt);
				goto out_nfserr;
			} else {
				exp_put(exp);
				exp = exp2;
			}
			mntput(mnt);
		}
	} else {
		fh_lock(fhp);
		dentry = lookup_one_len(name, dparent, len);
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		host_err = PTR_ERR(dentry);
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		if (IS_ERR(dentry))
			goto out_nfserr;
		/*
		 * check if we have crossed a mount point ...
		 */
		if (d_mountpoint(dentry)) {
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			if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
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				dput(dentry);
				goto out_nfserr;
			}
		}
	}
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	*dentry_ret = dentry;
	*exp_ret = exp;
	return 0;

out_nfserr:
	exp_put(exp);
	return nfserrno(host_err);
}

/*
 * Look up one component of a pathname.
 * N.B. After this call _both_ fhp and resfh need an fh_put
 *
 * If the lookup would cross a mountpoint, and the mounted filesystem
 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
 * accepted as it stands and the mounted directory is
 * returned. Otherwise the covered directory is returned.
 * NOTE: this mountpoint crossing is not supported properly by all
 *   clients and is explicitly disallowed for NFSv3
 *      NeilBrown <neilb@cse.unsw.edu.au>
 */
__be32
nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
					int len, struct svc_fh *resfh)
{
	struct svc_export	*exp;
	struct dentry		*dentry;
	__be32 err;

	err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
	if (err)
		return err;
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	err = check_nfsd_access(exp, rqstp);
	if (err)
		goto out;
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	/*
	 * Note: we compose the file handle now, but as the
	 * dentry may be negative, it may need to be updated.
	 */
	err = fh_compose(resfh, exp, dentry, fhp);
	if (!err && !dentry->d_inode)
		err = nfserr_noent;
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out:
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	dput(dentry);
	exp_put(exp);
	return err;
}

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/*
 * Set various file attributes.
 * N.B. After this call fhp needs an fh_put
 */
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__be32
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nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
	     int check_guard, time_t guardtime)
{
	struct dentry	*dentry;
	struct inode	*inode;
	int		accmode = MAY_SATTR;
	int		ftype = 0;
	int		imode;
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	__be32		err;
	int		host_err;
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	int		size_change = 0;

	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
		accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE;
	if (iap->ia_valid & ATTR_SIZE)
		ftype = S_IFREG;

	/* Get inode */
	err = fh_verify(rqstp, fhp, ftype, accmode);
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	if (err)
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		goto out;

	dentry = fhp->fh_dentry;
	inode = dentry->d_inode;

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	/* Ignore any mode updates on symlinks */
	if (S_ISLNK(inode->i_mode))
		iap->ia_valid &= ~ATTR_MODE;

	if (!iap->ia_valid)
		goto out;

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	/* NFSv2 does not differentiate between "set-[ac]time-to-now"
	 * which only requires access, and "set-[ac]time-to-X" which
	 * requires ownership.
	 * So if it looks like it might be "set both to the same time which
	 * is close to now", and if inode_change_ok fails, then we
	 * convert to "set to now" instead of "set to explicit time"
	 *
	 * We only call inode_change_ok as the last test as technically
	 * it is not an interface that we should be using.  It is only
	 * valid if the filesystem does not define it's own i_op->setattr.
	 */
#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
#define	MAX_TOUCH_TIME_ERROR (30*60)
	if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET
	    && iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec
	    ) {
	    /* Looks probable.  Now just make sure time is in the right ballpark.
	     * Solaris, at least, doesn't seem to care what the time request is.
	     * We require it be within 30 minutes of now.
	     */
	    time_t delta = iap->ia_atime.tv_sec - get_seconds();
	    if (delta<0) delta = -delta;
	    if (delta < MAX_TOUCH_TIME_ERROR &&
		inode_change_ok(inode, iap) != 0) {
		/* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME
		 * this will cause notify_change to set these times to "now"
		 */
		iap->ia_valid &= ~BOTH_TIME_SET;
	    }
	}
	    
	/* The size case is special. It changes the file as well as the attributes.  */
	if (iap->ia_valid & ATTR_SIZE) {
		if (iap->ia_size < inode->i_size) {
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			err = nfsd_permission(rqstp, fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
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			if (err)
				goto out;
		}

		/*
		 * If we are changing the size of the file, then
		 * we need to break all leases.
		 */
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		host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
		if (host_err == -EWOULDBLOCK)
			host_err = -ETIMEDOUT;
		if (host_err) /* ENOMEM or EWOULDBLOCK */
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			goto out_nfserr;

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		host_err = get_write_access(inode);
		if (host_err)
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			goto out_nfserr;

		size_change = 1;
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		host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
		if (host_err) {
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			put_write_access(inode);
			goto out_nfserr;
		}
		DQUOT_INIT(inode);
	}

	imode = inode->i_mode;
	if (iap->ia_valid & ATTR_MODE) {
		iap->ia_mode &= S_IALLUGO;
		imode = iap->ia_mode |= (imode & ~S_IALLUGO);
	}

	/* Revoke setuid/setgid bit on chown/chgrp */
	if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
		iap->ia_valid |= ATTR_KILL_SUID;
	if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
		iap->ia_valid |= ATTR_KILL_SGID;

	/* Change the attributes. */

	iap->ia_valid |= ATTR_CTIME;

	err = nfserr_notsync;
	if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
		fh_lock(fhp);
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		host_err = notify_change(dentry, iap);
		err = nfserrno(host_err);
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		fh_unlock(fhp);
	}
	if (size_change)
		put_write_access(inode);
	if (!err)
		if (EX_ISSYNC(fhp->fh_export))
			write_inode_now(inode, 1);
out:
	return err;

out_nfserr:
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	err = nfserrno(host_err);
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	goto out;
}

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#if defined(CONFIG_NFSD_V2_ACL) || \
    defined(CONFIG_NFSD_V3_ACL) || \
    defined(CONFIG_NFSD_V4)
static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
{
	ssize_t buflen;

	buflen = vfs_getxattr(dentry, key, NULL, 0);
	if (buflen <= 0)
		return buflen;
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	*buf = kmalloc(buflen, GFP_KERNEL);
	if (!*buf)
		return -ENOMEM;

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	return vfs_getxattr(dentry, key, *buf, buflen);
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}
#endif

#if defined(CONFIG_NFSD_V4)
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static int
set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
{
	int len;
	size_t buflen;
	char *buf = NULL;
	int error = 0;

	buflen = posix_acl_xattr_size(pacl->a_count);
	buf = kmalloc(buflen, GFP_KERNEL);
	error = -ENOMEM;
	if (buf == NULL)
		goto out;

	len = posix_acl_to_xattr(pacl, buf, buflen);
	if (len < 0) {
		error = len;
		goto out;
	}

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	error = vfs_setxattr(dentry, key, buf, len, 0);
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out:
	kfree(buf);
	return error;
}

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__be32
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nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
    struct nfs4_acl *acl)
{
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	__be32 error;
	int host_error;
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	struct dentry *dentry;
	struct inode *inode;
	struct posix_acl *pacl = NULL, *dpacl = NULL;
	unsigned int flags = 0;

	/* Get inode */
	error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR);
	if (error)
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		return error;
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	dentry = fhp->fh_dentry;
	inode = dentry->d_inode;
	if (S_ISDIR(inode->i_mode))
		flags = NFS4_ACL_DIR;

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	host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
	if (host_error == -EINVAL) {
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		return nfserr_attrnotsupp;
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	} else if (host_error < 0)
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		goto out_nfserr;

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	host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
	if (host_error < 0)
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		goto out_release;
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	if (S_ISDIR(inode->i_mode))
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		host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
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out_release:
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	posix_acl_release(pacl);
	posix_acl_release(dpacl);
out_nfserr:
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	if (host_error == -EOPNOTSUPP)
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		return nfserr_attrnotsupp;
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	else
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		return nfserrno(host_error);
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}

static struct posix_acl *
_get_posix_acl(struct dentry *dentry, char *key)
{
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	void *buf = NULL;
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	struct posix_acl *pacl = NULL;
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	int buflen;
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	buflen = nfsd_getxattr(dentry, key, &buf);
	if (!buflen)
		buflen = -ENODATA;
	if (buflen <= 0)
		return ERR_PTR(buflen);
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	pacl = posix_acl_from_xattr(buf, buflen);
	kfree(buf);
	return pacl;
}

int
nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
{
	struct inode *inode = dentry->d_inode;
	int error = 0;
	struct posix_acl *pacl = NULL, *dpacl = NULL;
	unsigned int flags = 0;

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	pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
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	if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
		pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
	if (IS_ERR(pacl)) {
		error = PTR_ERR(pacl);
		pacl = NULL;
		goto out;
	}

	if (S_ISDIR(inode->i_mode)) {
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		dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
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		if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
			dpacl = NULL;
		else if (IS_ERR(dpacl)) {
			error = PTR_ERR(dpacl);
			dpacl = NULL;
			goto out;
		}
		flags = NFS4_ACL_DIR;
	}

	*acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
	if (IS_ERR(*acl)) {
		error = PTR_ERR(*acl);
		*acl = NULL;
	}
 out:
	posix_acl_release(pacl);
	posix_acl_release(dpacl);
	return error;
}

#endif /* defined(CONFIG_NFS_V4) */

#ifdef CONFIG_NFSD_V3
/*
 * Check server access rights to a file system object
 */
struct accessmap {
	u32		access;
	int		how;
};
static struct accessmap	nfs3_regaccess[] = {
    {	NFS3_ACCESS_READ,	MAY_READ			},
    {	NFS3_ACCESS_EXECUTE,	MAY_EXEC			},
    {	NFS3_ACCESS_MODIFY,	MAY_WRITE|MAY_TRUNC		},
    {	NFS3_ACCESS_EXTEND,	MAY_WRITE			},

    {	0,			0				}
};

static struct accessmap	nfs3_diraccess[] = {
    {	NFS3_ACCESS_READ,	MAY_READ			},
    {	NFS3_ACCESS_LOOKUP,	MAY_EXEC			},
    {	NFS3_ACCESS_MODIFY,	MAY_EXEC|MAY_WRITE|MAY_TRUNC	},
    {	NFS3_ACCESS_EXTEND,	MAY_EXEC|MAY_WRITE		},
    {	NFS3_ACCESS_DELETE,	MAY_REMOVE			},

    {	0,			0				}
};

static struct accessmap	nfs3_anyaccess[] = {
	/* Some clients - Solaris 2.6 at least, make an access call
	 * to the server to check for access for things like /dev/null
	 * (which really, the server doesn't care about).  So
	 * We provide simple access checking for them, looking
	 * mainly at mode bits, and we make sure to ignore read-only
	 * filesystem checks
	 */
    {	NFS3_ACCESS_READ,	MAY_READ			},
    {	NFS3_ACCESS_EXECUTE,	MAY_EXEC			},
    {	NFS3_ACCESS_MODIFY,	MAY_WRITE|MAY_LOCAL_ACCESS	},
    {	NFS3_ACCESS_EXTEND,	MAY_WRITE|MAY_LOCAL_ACCESS	},

    {	0,			0				}
};

588
__be32
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nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
{
	struct accessmap	*map;
	struct svc_export	*export;
	struct dentry		*dentry;
	u32			query, result = 0, sresult = 0;
595
	__be32			error;
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	error = fh_verify(rqstp, fhp, 0, MAY_NOP);
	if (error)
		goto out;

	export = fhp->fh_export;
	dentry = fhp->fh_dentry;

	if (S_ISREG(dentry->d_inode->i_mode))
		map = nfs3_regaccess;
	else if (S_ISDIR(dentry->d_inode->i_mode))
		map = nfs3_diraccess;
	else
		map = nfs3_anyaccess;


	query = *access;
	for  (; map->access; map++) {
		if (map->access & query) {
615
			__be32 err2;
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			sresult |= map->access;

619
			err2 = nfsd_permission(rqstp, export, dentry, map->how);
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			switch (err2) {
			case nfs_ok:
				result |= map->access;
				break;
				
			/* the following error codes just mean the access was not allowed,
			 * rather than an error occurred */
			case nfserr_rofs:
			case nfserr_acces:
			case nfserr_perm:
				/* simply don't "or" in the access bit. */
				break;
			default:
				error = err2;
				goto out;
			}
		}
	}
	*access = result;
	if (supported)
		*supported = sresult;

 out:
	return error;
}
#endif /* CONFIG_NFSD_V3 */



/*
 * Open an existing file or directory.
 * The access argument indicates the type of open (read/write/lock)
 * N.B. After this call fhp needs an fh_put
 */
654
__be32
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nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
			int access, struct file **filp)
{
	struct dentry	*dentry;
	struct inode	*inode;
660 661 662
	int		flags = O_RDONLY|O_LARGEFILE;
	__be32		err;
	int		host_err;
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	/*
	 * If we get here, then the client has already done an "open",
	 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
	 * in case a chmod has now revoked permission.
	 */
	err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE);
	if (err)
		goto out;

	dentry = fhp->fh_dentry;
	inode = dentry->d_inode;

	/* Disallow write access to files with the append-only bit set
	 * or any access when mandatory locking enabled
	 */
	err = nfserr_perm;
	if (IS_APPEND(inode) && (access & MAY_WRITE))
		goto out;
	if (IS_ISMNDLK(inode))
		goto out;

	if (!inode->i_fop)
		goto out;

	/*
	 * Check to see if there are any leases on this file.
	 * This may block while leases are broken.
	 */
692 693 694 695
	host_err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0));
	if (host_err == -EWOULDBLOCK)
		host_err = -ETIMEDOUT;
	if (host_err) /* NOMEM or WOULDBLOCK */
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		goto out_nfserr;

	if (access & MAY_WRITE) {
699 700 701 702
		if (access & MAY_READ)
			flags = O_RDWR|O_LARGEFILE;
		else
			flags = O_WRONLY|O_LARGEFILE;
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		DQUOT_INIT(inode);
	}
	*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags);
	if (IS_ERR(*filp))
708
		host_err = PTR_ERR(*filp);
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out_nfserr:
710
	err = nfserrno(host_err);
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out:
	return err;
}

/*
 * Close a file.
 */
void
nfsd_close(struct file *filp)
{
	fput(filp);
}

/*
 * Sync a file
 * As this calls fsync (not fdatasync) there is no need for a write_inode
 * after it.
 */
729
static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
730
			      const struct file_operations *fop)
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{
	struct inode *inode = dp->d_inode;
	int (*fsync) (struct file *, struct dentry *, int);
734
	int err;
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736 737 738 739 740
	err = filemap_fdatawrite(inode->i_mapping);
	if (err == 0 && fop && (fsync = fop->fsync))
		err = fsync(filp, dp, 0);
	if (err == 0)
		err = filemap_fdatawait(inode->i_mapping);
741

742
	return err;
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}
	

746
static int
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nfsd_sync(struct file *filp)
{
749
        int err;
750 751
	struct inode *inode = filp->f_path.dentry->d_inode;
	dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
752
	mutex_lock(&inode->i_mutex);
753
	err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
754
	mutex_unlock(&inode->i_mutex);
755 756

	return err;
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}

759
int
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nfsd_sync_dir(struct dentry *dp)
{
762
	return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
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}

/*
 * Obtain the readahead parameters for the file
 * specified by (dev, ino).
 */

static inline struct raparms *
nfsd_get_raparms(dev_t dev, ino_t ino)
{
	struct raparms	*ra, **rap, **frap = NULL;
	int depth = 0;
775 776 777 778 779
	unsigned int hash;
	struct raparm_hbucket *rab;

	hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
	rab = &raparm_hash[hash];
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781 782
	spin_lock(&rab->pb_lock);
	for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
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		if (ra->p_ino == ino && ra->p_dev == dev)
			goto found;
		depth++;
		if (ra->p_count == 0)
			frap = rap;
	}
	depth = nfsdstats.ra_size*11/10;
	if (!frap) {	
791
		spin_unlock(&rab->pb_lock);
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		return NULL;
	}
	rap = frap;
	ra = *frap;
	ra->p_dev = dev;
	ra->p_ino = ino;
	ra->p_set = 0;
799
	ra->p_hindex = hash;
L
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found:
801
	if (rap != &rab->pb_head) {
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		*rap = ra->p_next;
803 804
		ra->p_next   = rab->pb_head;
		rab->pb_head = ra;
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	}
	ra->p_count++;
	nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
808
	spin_unlock(&rab->pb_lock);
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	return ra;
}

/*
813 814 815
 * Grab and keep cached pages associated with a file in the svc_rqst
 * so that they can be passed to the network sendmsg/sendpage routines
 * directly. They will be released after the sending has completed.
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 */
static int
818 819
nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
		  struct splice_desc *sd)
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{
821
	struct svc_rqst *rqstp = sd->u.data;
822
	struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
823 824 825
	struct page *page = buf->page;
	size_t size;
	int ret;
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827
	ret = buf->ops->confirm(pipe, buf);
828 829 830 831
	if (unlikely(ret))
		return ret;

	size = sd->len;
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	if (rqstp->rq_res.page_len == 0) {
		get_page(page);
835 836 837
		put_page(*pp);
		*pp = page;
		rqstp->rq_resused++;
838
		rqstp->rq_res.page_base = buf->offset;
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		rqstp->rq_res.page_len = size;
840
	} else if (page != pp[-1]) {
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		get_page(page);
842 843
		if (*pp)
			put_page(*pp);
844 845
		*pp = page;
		rqstp->rq_resused++;
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		rqstp->rq_res.page_len += size;
847
	} else
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		rqstp->rq_res.page_len += size;

	return size;
}

853 854 855 856 857 858
static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
				    struct splice_desc *sd)
{
	return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
}

859
static __be32
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nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
              loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
{
	struct inode *inode;
	struct raparms	*ra;
	mm_segment_t	oldfs;
866 867
	__be32		err;
	int		host_err;
L
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	err = nfserr_perm;
870
	inode = file->f_path.dentry->d_inode;
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#ifdef MSNFS
	if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
		(!lock_may_read(inode, offset, *count)))
		goto out;
#endif

	/* Get readahead parameters */
	ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);

	if (ra && ra->p_set)
		file->f_ra = ra->p_ra;

883 884 885 886 887 888 889 890
	if (file->f_op->splice_read && rqstp->rq_splice_ok) {
		struct splice_desc sd = {
			.len		= 0,
			.total_len	= *count,
			.pos		= offset,
			.u.data		= rqstp,
		};

891
		rqstp->rq_resused = 1;
892
		host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
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	} else {
		oldfs = get_fs();
		set_fs(KERNEL_DS);
896
		host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
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		set_fs(oldfs);
	}

	/* Write back readahead params */
	if (ra) {
902 903
		struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
		spin_lock(&rab->pb_lock);
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		ra->p_ra = file->f_ra;
		ra->p_set = 1;
		ra->p_count--;
907
		spin_unlock(&rab->pb_lock);
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	}

910 911 912
	if (host_err >= 0) {
		nfsdstats.io_read += host_err;
		*count = host_err;
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913
		err = 0;
914
		fsnotify_access(file->f_path.dentry);
L
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915
	} else 
916
		err = nfserrno(host_err);
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out:
	return err;
}

921 922 923 924 925
static void kill_suid(struct dentry *dentry)
{
	struct iattr	ia;
	ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID;

926
	mutex_lock(&dentry->d_inode->i_mutex);
927
	notify_change(dentry, &ia);
928
	mutex_unlock(&dentry->d_inode->i_mutex);
929 930
}

931
static __be32
L
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932 933 934 935 936 937 938 939
nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
				loff_t offset, struct kvec *vec, int vlen,
	   			unsigned long cnt, int *stablep)
{
	struct svc_export	*exp;
	struct dentry		*dentry;
	struct inode		*inode;
	mm_segment_t		oldfs;
940 941
	__be32			err = 0;
	int			host_err;
L
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942 943
	int			stable = *stablep;

944
#ifdef MSNFS
L
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945 946 947
	err = nfserr_perm;

	if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
948
		(!lock_may_write(file->f_path.dentry->d_inode, offset, cnt)))
L
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		goto out;
#endif

952
	dentry = file->f_path.dentry;
L
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	inode = dentry->d_inode;
	exp   = fhp->fh_export;

	/*
	 * Request sync writes if
	 *  -	the sync export option has been set, or
	 *  -	the client requested O_SYNC behavior (NFSv3 feature).
	 *  -   The file system doesn't support fsync().
	 * When gathered writes have been configured for this volume,
	 * flushing the data to disk is handled separately below.
	 */

	if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */
	       stable = 2;
	       *stablep = 2; /* FILE_SYNC */
	}

	if (!EX_ISSYNC(exp))
		stable = 0;
	if (stable && !EX_WGATHER(exp))
		file->f_flags |= O_SYNC;

	/* Write the data. */
	oldfs = get_fs(); set_fs(KERNEL_DS);
977
	host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
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	set_fs(oldfs);
979
	if (host_err >= 0) {
L
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980
		nfsdstats.io_write += cnt;
981
		fsnotify_modify(file->f_path.dentry);
L
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982 983 984
	}

	/* clear setuid/setgid flag after write */
985
	if (host_err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID)))
986
		kill_suid(dentry);
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987

988
	if (host_err >= 0 && stable) {
L
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		static ino_t	last_ino;
		static dev_t	last_dev;

		/*
		 * Gathered writes: If another process is currently
		 * writing to the file, there's a high chance
		 * this is another nfsd (triggered by a bulk write
		 * from a client's biod). Rather than syncing the
		 * file with each write request, we sleep for 10 msec.
		 *
		 * I don't know if this roughly approximates
		 * C. Juszak's idea of gathered writes, but it's a
		 * nice and simple solution (IMHO), and it seems to
		 * work:-)
		 */
		if (EX_WGATHER(exp)) {
			if (atomic_read(&inode->i_writecount) > 1
			    || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
				dprintk("nfsd: write defer %d\n", current->pid);
				msleep(10);
				dprintk("nfsd: write resume %d\n", current->pid);
			}

			if (inode->i_state & I_DIRTY) {
				dprintk("nfsd: write sync %d\n", current->pid);
1014
				host_err=nfsd_sync(file);
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			}
#if 0
			wake_up(&inode->i_wait);
#endif
		}
		last_ino = inode->i_ino;
		last_dev = inode->i_sb->s_dev;
	}

1024 1025
	dprintk("nfsd: write complete host_err=%d\n", host_err);
	if (host_err >= 0)
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		err = 0;
	else 
1028
		err = nfserrno(host_err);
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out:
	return err;
}

/*
 * Read data from a file. count must contain the requested read count
 * on entry. On return, *count contains the number of bytes actually read.
 * N.B. After this call fhp needs an fh_put
 */
1038
__be32
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nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
		loff_t offset, struct kvec *vec, int vlen,
		unsigned long *count)
{
1043
	__be32		err;
L
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1044 1045

	if (file) {
1046
		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
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				MAY_READ|MAY_OWNER_OVERRIDE);
		if (err)
			goto out;
		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
	} else {
		err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
		if (err)
			goto out;
		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
		nfsd_close(file);
	}
out:
	return err;
}

/*
 * Write data to a file.
 * The stable flag requests synchronous writes.
 * N.B. After this call fhp needs an fh_put
 */
1067
__be32
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nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
		loff_t offset, struct kvec *vec, int vlen, unsigned long cnt,
		int *stablep)
{
1072
	__be32			err = 0;
L
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	if (file) {
1075
		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
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				MAY_WRITE|MAY_OWNER_OVERRIDE);
		if (err)
			goto out;
		err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
				stablep);
	} else {
		err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
		if (err)
			goto out;

		if (cnt)
			err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
					     cnt, stablep);
		nfsd_close(file);
	}
out:
	return err;
}

#ifdef CONFIG_NFSD_V3
/*
 * Commit all pending writes to stable storage.
 * Strictly speaking, we could sync just the indicated file region here,
 * but there's currently no way we can ask the VFS to do so.
 *
 * Unfortunately we cannot lock the file to make sure we return full WCC
 * data to the client, as locking happens lower down in the filesystem.
 */
1104
__be32
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nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
               loff_t offset, unsigned long count)
{
	struct file	*file;
1109
	__be32		err;
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	if ((u64)count > ~(u64)offset)
		return nfserr_inval;

	if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0)
		return err;
	if (EX_ISSYNC(fhp->fh_export)) {
		if (file->f_op && file->f_op->fsync) {
1118
			err = nfserrno(nfsd_sync(file));
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		} else {
			err = nfserr_notsupp;
		}
	}

	nfsd_close(file);
	return err;
}
#endif /* CONFIG_NFSD_V3 */

/*
 * 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
 */
1137
__be32
L
Linus Torvalds 已提交
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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;
1144 1145
	__be32		err;
	int		host_err;
L
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1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169

	err = nfserr_perm;
	if (!flen)
		goto out;
	err = nfserr_exist;
	if (isdotent(fname, flen))
		goto out;

	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
	if (err)
		goto out;

	dentry = fhp->fh_dentry;
	dirp = dentry->d_inode;

	err = nfserr_notdir;
	if(!dirp->i_op || !dirp->i_op->lookup)
		goto out;
	/*
	 * Check whether the response file handle has been verified yet.
	 * If it has, the parent directory should already be locked.
	 */
	if (!resfhp->fh_dentry) {
		/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
P
Peter Zijlstra 已提交
1170
		fh_lock_nested(fhp, I_MUTEX_PARENT);
L
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1171
		dchild = lookup_one_len(fname, dentry, flen);
1172
		host_err = PTR_ERR(dchild);
L
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		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 %s/%s not locked!\n",
				dentry->d_parent->d_name.name,
				dentry->d_name.name);
A
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1187
			err = nfserr_io;
L
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			goto out;
		}
	}
	/*
	 * Make sure the child dentry is still negative ...
	 */
	err = nfserr_exist;
	if (dchild->d_inode) {
		dprintk("nfsd_create: dentry %s/%s not negative!\n",
			dentry->d_name.name, dchild->d_name.name);
		goto out; 
	}

	if (!(iap->ia_valid & ATTR_MODE))
		iap->ia_mode = 0;
	iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;

	/*
	 * Get the dir op function pointer.
	 */
1208
	err = 0;
L
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	switch (type) {
	case S_IFREG:
1211
		host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
L
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1212 1213
		break;
	case S_IFDIR:
1214
		host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
L
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1215 1216 1217 1218 1219
		break;
	case S_IFCHR:
	case S_IFBLK:
	case S_IFIFO:
	case S_IFSOCK:
1220
		host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
L
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		break;
	default:
	        printk("nfsd: bad file type %o in nfsd_create\n", type);
1224
		host_err = -EINVAL;
L
Linus Torvalds 已提交
1225
	}
1226
	if (host_err < 0)
L
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1227 1228 1229
		goto out_nfserr;

	if (EX_ISSYNC(fhp->fh_export)) {
1230
		err = nfserrno(nfsd_sync_dir(dentry));
L
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		write_inode_now(dchild->d_inode, 1);
	}


	/* Set file attributes. Mode has already been set and
	 * setting uid/gid works only for root. Irix appears to
	 * send along the gid when it tries to implement setgid
	 * directories via NFS.
	 */
1240
	if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
1241
		__be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1242 1243 1244
		if (err2)
			err = err2;
	}
L
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	/*
	 * Update the file handle to get the new inode info.
	 */
	if (!err)
		err = fh_update(resfhp);
out:
	if (dchild && !IS_ERR(dchild))
		dput(dchild);
	return err;

out_nfserr:
1256
	err = nfserrno(host_err);
L
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	goto out;
}

#ifdef CONFIG_NFSD_V3
/*
 * NFSv3 version of nfsd_create
 */
1264
__be32
L
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nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
		char *fname, int flen, struct iattr *iap,
		struct svc_fh *resfhp, int createmode, u32 *verifier,
1268
	        int *truncp, int *created)
L
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{
	struct dentry	*dentry, *dchild = NULL;
	struct inode	*dirp;
1272 1273
	__be32		err;
	int		host_err;
L
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	__u32		v_mtime=0, v_atime=0;

	err = nfserr_perm;
	if (!flen)
		goto out;
	err = nfserr_exist;
	if (isdotent(fname, flen))
		goto out;
	if (!(iap->ia_valid & ATTR_MODE))
		iap->ia_mode = 0;
	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
	if (err)
		goto out;

	dentry = fhp->fh_dentry;
	dirp = dentry->d_inode;

	/* Get all the sanity checks out of the way before
	 * we lock the parent. */
	err = nfserr_notdir;
	if(!dirp->i_op || !dirp->i_op->lookup)
		goto out;
P
Peter Zijlstra 已提交
1296
	fh_lock_nested(fhp, I_MUTEX_PARENT);
L
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1297 1298 1299 1300 1301

	/*
	 * Compose the response file handle.
	 */
	dchild = lookup_one_len(fname, dentry, flen);
1302
	host_err = PTR_ERR(dchild);
L
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	if (IS_ERR(dchild))
		goto out_nfserr;

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

	if (createmode == NFS3_CREATE_EXCLUSIVE) {
1311 1312
		/* solaris7 gets confused (bugid 4218508) if these have
		 * the high bit set, so just clear the high bits.
L
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		 */
		v_mtime = verifier[0]&0x7fffffff;
		v_atime = verifier[1]&0x7fffffff;
	}
	
	if (dchild->d_inode) {
		err = 0;

		switch (createmode) {
		case NFS3_CREATE_UNCHECKED:
			if (! S_ISREG(dchild->d_inode->i_mode))
				err = nfserr_exist;
			else if (truncp) {
				/* in nfsv4, we need to treat this case a little
				 * differently.  we don't want to truncate the
				 * file now; this would be wrong if the OPEN
				 * fails for some other reason.  furthermore,
				 * if the size is nonzero, we should ignore it
				 * according to spec!
				 */
				*truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
			}
			else {
				iap->ia_valid &= ATTR_SIZE;
				goto set_attr;
			}
			break;
		case NFS3_CREATE_EXCLUSIVE:
			if (   dchild->d_inode->i_mtime.tv_sec == v_mtime
			    && dchild->d_inode->i_atime.tv_sec == v_atime
			    && dchild->d_inode->i_size  == 0 )
				break;
			 /* fallthru */
		case NFS3_CREATE_GUARDED:
			err = nfserr_exist;
		}
		goto out;
	}

1352 1353
	host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
	if (host_err < 0)
L
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1354
		goto out_nfserr;
1355 1356
	if (created)
		*created = 1;
L
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1357 1358

	if (EX_ISSYNC(fhp->fh_export)) {
1359
		err = nfserrno(nfsd_sync_dir(dentry));
L
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1360 1361 1362 1363
		/* setattr will sync the child (or not) */
	}

	if (createmode == NFS3_CREATE_EXCLUSIVE) {
1364
		/* Cram the verifier into atime/mtime */
L
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1365
		iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1366
			| ATTR_MTIME_SET|ATTR_ATIME_SET;
L
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1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378
		/* XXX someone who knows this better please fix it for nsec */ 
		iap->ia_mtime.tv_sec = v_mtime;
		iap->ia_atime.tv_sec = v_atime;
		iap->ia_mtime.tv_nsec = 0;
		iap->ia_atime.tv_nsec = 0;
	}

	/* Set file attributes.
	 * Irix appears to send along the gid when it tries to
	 * implement setgid directories via NFS. Clear out all that cruft.
	 */
 set_attr:
1379
	if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
1380
 		__be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1381
		if (err2)
1382
			err = err2;
1383 1384 1385 1386 1387 1388 1389
	}

	/*
	 * Update the filehandle to get the new inode info.
	 */
	if (!err)
		err = fh_update(resfhp);
L
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1390 1391 1392 1393 1394 1395 1396 1397

 out:
	fh_unlock(fhp);
	if (dchild && !IS_ERR(dchild))
		dput(dchild);
 	return err;
 
 out_nfserr:
1398
	err = nfserrno(host_err);
L
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1399 1400 1401 1402 1403 1404 1405 1406 1407
	goto out;
}
#endif /* CONFIG_NFSD_V3 */

/*
 * Read a symlink. On entry, *lenp must contain the maximum path length that
 * fits into the buffer. On return, it contains the true length.
 * N.B. After this call fhp needs an fh_put
 */
1408
__be32
L
Linus Torvalds 已提交
1409 1410 1411 1412 1413
nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
{
	struct dentry	*dentry;
	struct inode	*inode;
	mm_segment_t	oldfs;
1414 1415
	__be32		err;
	int		host_err;
L
Linus Torvalds 已提交
1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433

	err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP);
	if (err)
		goto out;

	dentry = fhp->fh_dentry;
	inode = dentry->d_inode;

	err = nfserr_inval;
	if (!inode->i_op || !inode->i_op->readlink)
		goto out;

	touch_atime(fhp->fh_export->ex_mnt, dentry);
	/* N.B. Why does this call need a get_fs()??
	 * Remove the set_fs and watch the fireworks:-) --okir
	 */

	oldfs = get_fs(); set_fs(KERNEL_DS);
1434
	host_err = inode->i_op->readlink(dentry, buf, *lenp);
L
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1435 1436
	set_fs(oldfs);

1437
	if (host_err < 0)
L
Linus Torvalds 已提交
1438
		goto out_nfserr;
1439
	*lenp = host_err;
L
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1440 1441 1442 1443 1444
	err = 0;
out:
	return err;

out_nfserr:
1445
	err = nfserrno(host_err);
L
Linus Torvalds 已提交
1446 1447 1448 1449 1450 1451 1452
	goto out;
}

/*
 * Create a symlink and look up its inode
 * N.B. After this call _both_ fhp and resfhp need an fh_put
 */
1453
__be32
L
Linus Torvalds 已提交
1454 1455 1456 1457 1458 1459 1460
nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
				char *fname, int flen,
				char *path,  int plen,
				struct svc_fh *resfhp,
				struct iattr *iap)
{
	struct dentry	*dentry, *dnew;
1461 1462
	__be32		err, cerr;
	int		host_err;
L
Linus Torvalds 已提交
1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
	umode_t		mode;

	err = nfserr_noent;
	if (!flen || !plen)
		goto out;
	err = nfserr_exist;
	if (isdotent(fname, flen))
		goto out;

	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
	if (err)
		goto out;
	fh_lock(fhp);
	dentry = fhp->fh_dentry;
	dnew = lookup_one_len(fname, dentry, flen);
1478
	host_err = PTR_ERR(dnew);
L
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1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489
	if (IS_ERR(dnew))
		goto out_nfserr;

	mode = S_IALLUGO;
	/* Only the MODE ATTRibute is even vaguely meaningful */
	if (iap && (iap->ia_valid & ATTR_MODE))
		mode = iap->ia_mode & S_IALLUGO;

	if (unlikely(path[plen] != 0)) {
		char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
		if (path_alloced == NULL)
1490
			host_err = -ENOMEM;
L
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1491 1492 1493
		else {
			strncpy(path_alloced, path, plen);
			path_alloced[plen] = 0;
1494
			host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
L
Linus Torvalds 已提交
1495 1496 1497
			kfree(path_alloced);
		}
	} else
1498
		host_err = vfs_symlink(dentry->d_inode, dnew, path, mode);
L
Linus Torvalds 已提交
1499

1500
	if (!host_err) {
L
Linus Torvalds 已提交
1501
		if (EX_ISSYNC(fhp->fh_export))
1502 1503 1504
			host_err = nfsd_sync_dir(dentry);
	}
	err = nfserrno(host_err);
L
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1505 1506 1507 1508 1509 1510 1511 1512 1513
	fh_unlock(fhp);

	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
	dput(dnew);
	if (err==0) err = cerr;
out:
	return err;

out_nfserr:
1514
	err = nfserrno(host_err);
L
Linus Torvalds 已提交
1515 1516 1517 1518 1519 1520 1521
	goto out;
}

/*
 * Create a hardlink
 * N.B. After this call _both_ ffhp and tfhp need an fh_put
 */
1522
__be32
L
Linus Torvalds 已提交
1523 1524 1525 1526 1527
nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
				char *name, int len, struct svc_fh *tfhp)
{
	struct dentry	*ddir, *dnew, *dold;
	struct inode	*dirp, *dest;
1528 1529
	__be32		err;
	int		host_err;
L
Linus Torvalds 已提交
1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544

	err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE);
	if (err)
		goto out;
	err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP);
	if (err)
		goto out;

	err = nfserr_perm;
	if (!len)
		goto out;
	err = nfserr_exist;
	if (isdotent(name, len))
		goto out;

P
Peter Zijlstra 已提交
1545
	fh_lock_nested(ffhp, I_MUTEX_PARENT);
L
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1546 1547 1548 1549
	ddir = ffhp->fh_dentry;
	dirp = ddir->d_inode;

	dnew = lookup_one_len(name, ddir, len);
1550
	host_err = PTR_ERR(dnew);
L
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1551 1552 1553 1554 1555 1556
	if (IS_ERR(dnew))
		goto out_nfserr;

	dold = tfhp->fh_dentry;
	dest = dold->d_inode;

1557 1558
	host_err = vfs_link(dold, dirp, dnew);
	if (!host_err) {
L
Linus Torvalds 已提交
1559
		if (EX_ISSYNC(ffhp->fh_export)) {
1560
			err = nfserrno(nfsd_sync_dir(ddir));
L
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1561 1562
			write_inode_now(dest, 1);
		}
1563
		err = 0;
L
Linus Torvalds 已提交
1564
	} else {
1565
		if (host_err == -EXDEV && rqstp->rq_vers == 2)
L
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1566 1567
			err = nfserr_acces;
		else
1568
			err = nfserrno(host_err);
L
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1569 1570 1571
	}

	dput(dnew);
1572 1573
out_unlock:
	fh_unlock(ffhp);
L
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1574 1575 1576 1577
out:
	return err;

out_nfserr:
1578
	err = nfserrno(host_err);
1579
	goto out_unlock;
L
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1580 1581 1582 1583 1584 1585
}

/*
 * Rename a file
 * N.B. After this call _both_ ffhp and tfhp need an fh_put
 */
1586
__be32
L
Linus Torvalds 已提交
1587 1588 1589 1590 1591
nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
			    struct svc_fh *tfhp, char *tname, int tlen)
{
	struct dentry	*fdentry, *tdentry, *odentry, *ndentry, *trap;
	struct inode	*fdir, *tdir;
1592 1593
	__be32		err;
	int		host_err;
L
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1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608

	err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE);
	if (err)
		goto out;
	err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE);
	if (err)
		goto out;

	fdentry = ffhp->fh_dentry;
	fdir = fdentry->d_inode;

	tdentry = tfhp->fh_dentry;
	tdir = tdentry->d_inode;

	err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1609
	if (ffhp->fh_export != tfhp->fh_export)
L
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1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623
		goto out;

	err = nfserr_perm;
	if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
		goto out;

	/* cannot use fh_lock as we need deadlock protective ordering
	 * so do it by hand */
	trap = lock_rename(tdentry, fdentry);
	ffhp->fh_locked = tfhp->fh_locked = 1;
	fill_pre_wcc(ffhp);
	fill_pre_wcc(tfhp);

	odentry = lookup_one_len(fname, fdentry, flen);
1624
	host_err = PTR_ERR(odentry);
L
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1625 1626 1627
	if (IS_ERR(odentry))
		goto out_nfserr;

1628
	host_err = -ENOENT;
L
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1629 1630
	if (!odentry->d_inode)
		goto out_dput_old;
1631
	host_err = -EINVAL;
L
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1632 1633 1634 1635
	if (odentry == trap)
		goto out_dput_old;

	ndentry = lookup_one_len(tname, tdentry, tlen);
1636
	host_err = PTR_ERR(ndentry);
L
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1637 1638
	if (IS_ERR(ndentry))
		goto out_dput_old;
1639
	host_err = -ENOTEMPTY;
L
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1640 1641 1642 1643 1644 1645 1646
	if (ndentry == trap)
		goto out_dput_new;

#ifdef MSNFS
	if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
		((atomic_read(&odentry->d_count) > 1)
		 || (atomic_read(&ndentry->d_count) > 1))) {
1647
			host_err = -EPERM;
L
Linus Torvalds 已提交
1648 1649
	} else
#endif
1650 1651 1652 1653 1654
	host_err = vfs_rename(fdir, odentry, tdir, ndentry);
	if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
		host_err = nfsd_sync_dir(tdentry);
		if (!host_err)
			host_err = nfsd_sync_dir(fdentry);
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1655 1656 1657 1658 1659 1660 1661
	}

 out_dput_new:
	dput(ndentry);
 out_dput_old:
	dput(odentry);
 out_nfserr:
1662
	err = nfserrno(host_err);
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	/* we cannot reply on fh_unlock on the two filehandles,
	 * as that would do the wrong thing if the two directories
	 * were the same, so again we do it by hand
	 */
	fill_post_wcc(ffhp);
	fill_post_wcc(tfhp);
	unlock_rename(tdentry, fdentry);
	ffhp->fh_locked = tfhp->fh_locked = 0;

out:
	return err;
}

/*
 * Unlink a file or directory
 * N.B. After this call fhp needs an fh_put
 */
1681
__be32
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nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
				char *fname, int flen)
{
	struct dentry	*dentry, *rdentry;
	struct inode	*dirp;
1687 1688
	__be32		err;
	int		host_err;
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	err = nfserr_acces;
	if (!flen || isdotent(fname, flen))
		goto out;
	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE);
	if (err)
		goto out;

P
Peter Zijlstra 已提交
1697
	fh_lock_nested(fhp, I_MUTEX_PARENT);
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	dentry = fhp->fh_dentry;
	dirp = dentry->d_inode;

	rdentry = lookup_one_len(fname, dentry, flen);
1702
	host_err = PTR_ERR(rdentry);
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	if (IS_ERR(rdentry))
		goto out_nfserr;

	if (!rdentry->d_inode) {
		dput(rdentry);
		err = nfserr_noent;
		goto out;
	}

	if (!type)
		type = rdentry->d_inode->i_mode & S_IFMT;

	if (type != S_IFDIR) { /* It's UNLINK */
#ifdef MSNFS
		if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
			(atomic_read(&rdentry->d_count) > 1)) {
1719
			host_err = -EPERM;
L
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		} else
#endif
1722
		host_err = vfs_unlink(dirp, rdentry);
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	} else { /* It's RMDIR */
1724
		host_err = vfs_rmdir(dirp, rdentry);
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	}

	dput(rdentry);

1729 1730 1731 1732
	if (host_err)
		goto out_nfserr;
	if (EX_ISSYNC(fhp->fh_export))
		host_err = nfsd_sync_dir(dentry);
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out_nfserr:
1735
	err = nfserrno(host_err);
1736 1737
out:
	return err;
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}

/*
 * Read entries from a directory.
 * The  NFSv3/4 verifier we ignore for now.
 */
1744
__be32
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nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 
1746
	     struct readdir_cd *cdp, filldir_t func)
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{
1748 1749
	__be32		err;
	int 		host_err;
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	struct file	*file;
	loff_t		offset = *offsetp;

	err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file);
	if (err)
		goto out;

	offset = vfs_llseek(file, offset, 0);
	if (offset < 0) {
		err = nfserrno((int)offset);
		goto out_close;
	}

	/*
	 * Read the directory entries. This silly loop is necessary because
	 * readdir() is not guaranteed to fill up the entire buffer, but
	 * may choose to do less.
	 */

	do {
		cdp->err = nfserr_eof; /* will be cleared on successful read */
1771
		host_err = vfs_readdir(file, func, cdp);
1772 1773 1774
	} while (host_err >=0 && cdp->err == nfs_ok);
	if (host_err)
		err = nfserrno(host_err);
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	else
		err = cdp->err;
	*offsetp = vfs_llseek(file, 0, 1);

	if (err == nfserr_eof || err == nfserr_toosmall)
		err = nfs_ok; /* can still be found in ->err */
out_close:
	nfsd_close(file);
out:
	return err;
}

/*
 * Get file system stats
 * N.B. After this call fhp needs an fh_put
 */
1791
__be32
L
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nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat)
{
1794
	__be32 err = fh_verify(rqstp, fhp, 0, MAY_NOP);
1795
	if (!err && vfs_statfs(fhp->fh_dentry,stat))
L
Linus Torvalds 已提交
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		err = nfserr_io;
	return err;
}

/*
 * Check for a user's access permissions to this inode.
 */
1803
__be32
1804 1805
nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
					struct dentry *dentry, int acc)
L
Linus Torvalds 已提交
1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835
{
	struct inode	*inode = dentry->d_inode;
	int		err;

	if (acc == MAY_NOP)
		return 0;
#if 0
	dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
		acc,
		(acc & MAY_READ)?	" read"  : "",
		(acc & MAY_WRITE)?	" write" : "",
		(acc & MAY_EXEC)?	" exec"  : "",
		(acc & MAY_SATTR)?	" sattr" : "",
		(acc & MAY_TRUNC)?	" trunc" : "",
		(acc & MAY_LOCK)?	" lock"  : "",
		(acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "",
		inode->i_mode,
		IS_IMMUTABLE(inode)?	" immut" : "",
		IS_APPEND(inode)?	" append" : "",
		IS_RDONLY(inode)?	" ro" : "");
	dprintk("      owner %d/%d user %d/%d\n",
		inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
#endif

	/* Normally we reject any write/sattr etc access on a read-only file
	 * system.  But if it is IRIX doing check on write-access for a 
	 * device special file, we ignore rofs.
	 */
	if (!(acc & MAY_LOCAL_ACCESS))
		if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
1836
			if (EX_RDONLY(exp, rqstp) || IS_RDONLY(inode))
L
Linus Torvalds 已提交
1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
				return nfserr_rofs;
			if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
				return nfserr_perm;
		}
	if ((acc & MAY_TRUNC) && IS_APPEND(inode))
		return nfserr_perm;

	if (acc & MAY_LOCK) {
		/* If we cannot rely on authentication in NLM requests,
		 * just allow locks, otherwise require read permission, or
		 * ownership
		 */
		if (exp->ex_flags & NFSEXP_NOAUTHNLM)
			return 0;
		else
			acc = MAY_READ | MAY_OWNER_OVERRIDE;
	}
	/*
	 * The file owner always gets access permission for accesses that
	 * would normally be checked at open time. This is to make
	 * file access work even when the client has done a fchmod(fd, 0).
	 *
	 * However, `cp foo bar' should fail nevertheless when bar is
	 * readonly. A sensible way to do this might be to reject all
	 * attempts to truncate a read-only file, because a creat() call
	 * always implies file truncation.
	 * ... but this isn't really fair.  A process may reasonably call
	 * ftruncate on an open file descriptor on a file with perm 000.
	 * We must trust the client to do permission checking - using "ACCESS"
	 * with NFSv3.
	 */
	if ((acc & MAY_OWNER_OVERRIDE) &&
	    inode->i_uid == current->fsuid)
		return 0;

	err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL);

	/* Allow read access to binaries even when mode 111 */
	if (err == -EACCES && S_ISREG(inode->i_mode) &&
	    acc == (MAY_READ | MAY_OWNER_OVERRIDE))
		err = permission(inode, MAY_EXEC, NULL);

	return err? nfserrno(err) : 0;
}

void
nfsd_racache_shutdown(void)
{
1885
	if (!raparml)
L
Linus Torvalds 已提交
1886 1887 1888
		return;
	dprintk("nfsd: freeing readahead buffers.\n");
	kfree(raparml);
1889
	raparml = NULL;
L
Linus Torvalds 已提交
1890 1891 1892 1893 1894 1895 1896 1897
}
/*
 * Initialize readahead param cache
 */
int
nfsd_racache_init(int cache_size)
{
	int	i;
1898 1899
	int	j = 0;
	int	nperbucket;
L
Linus Torvalds 已提交
1900

1901 1902

	if (raparml)
L
Linus Torvalds 已提交
1903
		return 0;
1904 1905
	if (cache_size < 2*RAPARM_HASH_SIZE)
		cache_size = 2*RAPARM_HASH_SIZE;
1906 1907 1908
	raparml = kcalloc(cache_size, sizeof(struct raparms), GFP_KERNEL);

	if (!raparml) {
L
Linus Torvalds 已提交
1909
		printk(KERN_WARNING
1910
			"nfsd: Could not allocate memory read-ahead cache.\n");
L
Linus Torvalds 已提交
1911 1912
		return -ENOMEM;
	}
1913 1914 1915 1916 1917 1918

	dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
	for (i = 0 ; i < RAPARM_HASH_SIZE ; i++) {
		raparm_hash[i].pb_head = NULL;
		spin_lock_init(&raparm_hash[i].pb_lock);
	}
1919
	nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
1920 1921 1922 1923 1924 1925 1926
	for (i = 0; i < cache_size - 1; i++) {
		if (i % nperbucket == 0)
			raparm_hash[j++].pb_head = raparml + i;
		if (i % nperbucket < nperbucket-1)
			raparml[i].p_next = raparml + i + 1;
	}

L
Linus Torvalds 已提交
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	nfsdstats.ra_size = cache_size;
	return 0;
}
1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940

#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
struct posix_acl *
nfsd_get_posix_acl(struct svc_fh *fhp, int type)
{
	struct inode *inode = fhp->fh_dentry->d_inode;
	char *name;
	void *value = NULL;
	ssize_t size;
	struct posix_acl *acl;

1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951
	if (!IS_POSIXACL(inode))
		return ERR_PTR(-EOPNOTSUPP);

	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		name = POSIX_ACL_XATTR_DEFAULT;
		break;
	default:
1952 1953 1954
		return ERR_PTR(-EOPNOTSUPP);
	}

1955 1956 1957
	size = nfsd_getxattr(fhp->fh_dentry, name, &value);
	if (size < 0)
		return ERR_PTR(size);
1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977

	acl = posix_acl_from_xattr(value, size);
	kfree(value);
	return acl;
}

int
nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
{
	struct inode *inode = fhp->fh_dentry->d_inode;
	char *name;
	void *value = NULL;
	size_t size;
	int error;

	if (!IS_POSIXACL(inode) || !inode->i_op ||
	    !inode->i_op->setxattr || !inode->i_op->removexattr)
		return -EOPNOTSUPP;
	switch(type) {
		case ACL_TYPE_ACCESS:
1978
			name = POSIX_ACL_XATTR_ACCESS;
1979 1980
			break;
		case ACL_TYPE_DEFAULT:
1981
			name = POSIX_ACL_XATTR_DEFAULT;
1982 1983 1984 1985 1986 1987
			break;
		default:
			return -EOPNOTSUPP;
	}

	if (acl && acl->a_count) {
1988
		size = posix_acl_xattr_size(acl->a_count);
1989 1990 1991
		value = kmalloc(size, GFP_KERNEL);
		if (!value)
			return -ENOMEM;
1992 1993
		error = posix_acl_to_xattr(acl, value, size);
		if (error < 0)
1994
			goto getout;
1995
		size = error;
1996 1997 1998 1999
	} else
		size = 0;

	if (size)
2000
		error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
2001 2002 2003 2004
	else {
		if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
			error = 0;
		else {
2005
			error = vfs_removexattr(fhp->fh_dentry, name);
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
			if (error == -ENODATA)
				error = 0;
		}
	}

getout:
	kfree(value);
	return error;
}
#endif  /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */