vfs.c 46.9 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>
#include <linux/ext2_fs.h>
#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
#define NFSD_PARANOIA


/* 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.
 * Returns -EAGAIN leaving *dpp and *expp unchanged, 
 *  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));

	exp2 = exp_get_by_name(exp->ex_client, mnt, mounts, &rqstp->rq_chandle);
	if (IS_ERR(exp2)) {
		err = PTR_ERR(exp2);
		dput(mounts);
		mntput(mnt);
		goto out;
	}
	if (exp2 && ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2))) {
		/* successfully crossed mount point */
		exp_put(exp);
		*expp = exp2;
		dput(dentry);
		*dpp = mounts;
	} else {
		if (exp2) exp_put(exp2);
		dput(mounts);
	}
	mntput(mnt);
out:
	return 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>
 */
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__be32
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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		*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);

	err = nfserr_acces;

	/* 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;

			exp2 = exp_parent(exp->ex_client, mnt, dentry,
					  &rqstp->rq_chandle);
			if (IS_ERR(exp2)) {
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				host_err = PTR_ERR(exp2);
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				dput(dentry);
				mntput(mnt);
				goto out_nfserr;
			}
			if (!exp2) {
				dput(dentry);
				dentry = dget(dparent);
			} 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;
			}
		}
	}
	/*
	 * 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;
	dput(dentry);
out:
	exp_put(exp);
	return err;

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

/*
 * Set various file attributes.
 * N.B. After this call fhp needs an fh_put
 */
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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) {
			err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
			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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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)
		goto out;

	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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		error = nfserr_attrnotsupp;
		goto out;
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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_nfserr;
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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);
		if (host_error < 0)
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			goto out_nfserr;
	}

	error = nfs_ok;

out:
	posix_acl_release(pacl);
	posix_acl_release(dpacl);
	return (error);
out_nfserr:
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	error = nfserrno(host_error);
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	goto out;
}

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				}
};

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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;
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	__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) {
604
			__be32 err2;
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			sresult |= map->access;

			err2 = nfsd_permission(export, dentry, map->how);
			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
 */
643
__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;
649 650 651
	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.
	 */
681 682 683 684
	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) {
688 689 690 691
		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))
697
		host_err = PTR_ERR(*filp);
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out_nfserr:
699
	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.
 */
718
static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
719
			      const struct file_operations *fop)
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{
	struct inode *inode = dp->d_inode;
	int (*fsync) (struct file *, struct dentry *, int);
723
	int err;
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725 726 727 728 729
	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);
730

731
	return err;
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}
	

735
static int
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nfsd_sync(struct file *filp)
{
738
        int err;
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	struct inode *inode = filp->f_dentry->d_inode;
	dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name);
741
	mutex_lock(&inode->i_mutex);
742
	err=nfsd_dosync(filp, filp->f_dentry, filp->f_op);
743
	mutex_unlock(&inode->i_mutex);
744 745

	return err;
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}

748
int
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nfsd_sync_dir(struct dentry *dp)
{
751
	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;
764 765 766 767 768
	unsigned int hash;
	struct raparm_hbucket *rab;

	hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
	rab = &raparm_hash[hash];
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770 771
	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) {	
780
		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;
788
	ra->p_hindex = hash;
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found:
790
	if (rap != &rab->pb_head) {
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		*rap = ra->p_next;
792 793
		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]++;
797
	spin_unlock(&rab->pb_lock);
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	return ra;
}

/*
 * Grab and keep cached pages assosiated with a file in the svc_rqst
 * so that they can be passed to the netowork sendmsg/sendpage routines
 * directrly. They will be released after the sending has completed.
 */
static int
nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset , unsigned long size)
{
	unsigned long count = desc->count;
	struct svc_rqst *rqstp = desc->arg.data;
811
	struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
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	if (size > count)
		size = count;

	if (rqstp->rq_res.page_len == 0) {
		get_page(page);
818 819 820
		put_page(*pp);
		*pp = page;
		rqstp->rq_resused++;
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		rqstp->rq_res.page_base = offset;
		rqstp->rq_res.page_len = size;
823
	} else if (page != pp[-1]) {
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		get_page(page);
825 826 827
		put_page(*pp);
		*pp = page;
		rqstp->rq_resused++;
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		rqstp->rq_res.page_len += size;
829
	} else
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		rqstp->rq_res.page_len += size;

	desc->count = count - size;
	desc->written += size;
	return size;
}

837
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;
844 845
	__be32		err;
	int		host_err;
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	err = nfserr_perm;
	inode = file->f_dentry->d_inode;
#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;

861
	if (file->f_op->sendfile && rqstp->rq_sendfile_ok) {
862
		rqstp->rq_resused = 1;
863
		host_err = file->f_op->sendfile(file, &offset, *count,
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						 nfsd_read_actor, rqstp);
	} else {
		oldfs = get_fs();
		set_fs(KERNEL_DS);
868
		host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
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		set_fs(oldfs);
	}

	/* Write back readahead params */
	if (ra) {
874 875
		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--;
879
		spin_unlock(&rab->pb_lock);
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	}

882 883 884
	if (host_err >= 0) {
		nfsdstats.io_read += host_err;
		*count = host_err;
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		err = 0;
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		fsnotify_access(file->f_dentry);
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	} else 
888
		err = nfserrno(host_err);
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out:
	return err;
}

893 894 895 896 897
static void kill_suid(struct dentry *dentry)
{
	struct iattr	ia;
	ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID;

898
	mutex_lock(&dentry->d_inode->i_mutex);
899
	notify_change(dentry, &ia);
900
	mutex_unlock(&dentry->d_inode->i_mutex);
901 902
}

903
static __be32
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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;
912 913
	__be32			err = 0;
	int			host_err;
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	int			stable = *stablep;

916
#ifdef MSNFS
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	err = nfserr_perm;

	if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
		(!lock_may_write(file->f_dentry->d_inode, offset, cnt)))
		goto out;
#endif

	dentry = file->f_dentry;
	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);
949
	host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
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	set_fs(oldfs);
951
	if (host_err >= 0) {
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		nfsdstats.io_write += cnt;
R
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		fsnotify_modify(file->f_dentry);
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	}

	/* clear setuid/setgid flag after write */
957
	if (host_err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID)))
958
		kill_suid(dentry);
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960
	if (host_err >= 0 && stable) {
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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);
986
				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;
	}

996 997
	dprintk("nfsd: write complete host_err=%d\n", host_err);
	if (host_err >= 0)
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		err = 0;
	else 
1000
		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
 */
1010
__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)
{
1015
	__be32		err;
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	if (file) {
		err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
				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
 */
1039
__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)
{
1044
	__be32			err = 0;
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	if (file) {
		err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
				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.
 */
1076
__be32
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nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
               loff_t offset, unsigned long count)
{
	struct file	*file;
1081
	__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) {
1090
			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
 */
1109
__be32
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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;
1116 1117
	__be32		err;
	int		host_err;
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	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 */
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		fh_lock_nested(fhp, I_MUTEX_PARENT);
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		dchild = lookup_one_len(fname, dentry, flen);
1144
		host_err = PTR_ERR(dchild);
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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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1159
			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.
	 */
	err = nfserr_perm;
	switch (type) {
	case S_IFREG:
1183
		host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
L
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		break;
	case S_IFDIR:
1186
		host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
L
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		break;
	case S_IFCHR:
	case S_IFBLK:
	case S_IFIFO:
	case S_IFSOCK:
1192
		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);
1196
		host_err = -EINVAL;
L
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	}
1198
	if (host_err < 0)
L
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		goto out_nfserr;

	if (EX_ISSYNC(fhp->fh_export)) {
1202
		err = nfserrno(nfsd_sync_dir(dentry));
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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.
	 */
1212
	if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
1213
		__be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1214 1215 1216
		if (err2)
			err = err2;
	}
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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:
1228
	err = nfserrno(host_err);
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	goto out;
}

#ifdef CONFIG_NFSD_V3
/*
 * NFSv3 version of nfsd_create
 */
1236
__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,
1240
	        int *truncp, int *created)
L
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{
	struct dentry	*dentry, *dchild = NULL;
	struct inode	*dirp;
1244 1245
	__be32		err;
	int		host_err;
L
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	__u32		v_mtime=0, v_atime=0;
	int		v_mode=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;
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	fh_lock_nested(fhp, I_MUTEX_PARENT);
L
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	/*
	 * Compose the response file handle.
	 */
	dchild = lookup_one_len(fname, dentry, flen);
1275
	host_err = PTR_ERR(dchild);
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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) {
		/* while the verifier would fit in mtime+atime,
		 * solaris7 gets confused (bugid 4218508) if these have
		 * the high bit set, so we use the mode as well
		 */
		v_mtime = verifier[0]&0x7fffffff;
		v_atime = verifier[1]&0x7fffffff;
		v_mode  = S_IFREG
			| ((verifier[0]&0x80000000) >> (32-7)) /* u+x */
			| ((verifier[1]&0x80000000) >> (32-9)) /* u+r */
			;
	}
	
	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_mode  == v_mode
			    && dchild->d_inode->i_size  == 0 )
				break;
			 /* fallthru */
		case NFS3_CREATE_GUARDED:
			err = nfserr_exist;
		}
		goto out;
	}

1331 1332
	host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
	if (host_err < 0)
L
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		goto out_nfserr;
1334 1335
	if (created)
		*created = 1;
L
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	if (EX_ISSYNC(fhp->fh_export)) {
1338
		err = nfserrno(nfsd_sync_dir(dentry));
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		/* setattr will sync the child (or not) */
	}

	if (createmode == NFS3_CREATE_EXCLUSIVE) {
		/* Cram the verifier into atime/mtime/mode */
		iap->ia_valid = ATTR_MTIME|ATTR_ATIME
			| ATTR_MTIME_SET|ATTR_ATIME_SET
			| ATTR_MODE;
		/* 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;
		iap->ia_mode  = v_mode;
	}

	/* Set file attributes.
	 * Mode has already been set but we might need to reset it
	 * for CREATE_EXCLUSIVE
	 * Irix appears to send along the gid when it tries to
	 * implement setgid directories via NFS. Clear out all that cruft.
	 */
 set_attr:
1362
	if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID)) != 0) {
1363
 		__be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1364
		if (err2)
1365
			err = err2;
1366 1367 1368 1369 1370 1371 1372
	}

	/*
	 * Update the filehandle to get the new inode info.
	 */
	if (!err)
		err = fh_update(resfhp);
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 out:
	fh_unlock(fhp);
	if (dchild && !IS_ERR(dchild))
		dput(dchild);
 	return err;
 
 out_nfserr:
1381
	err = nfserrno(host_err);
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	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
 */
1391
__be32
L
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nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
{
	struct dentry	*dentry;
	struct inode	*inode;
	mm_segment_t	oldfs;
1397 1398
	__be32		err;
	int		host_err;
L
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	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);
1417
	host_err = inode->i_op->readlink(dentry, buf, *lenp);
L
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	set_fs(oldfs);

1420
	if (host_err < 0)
L
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		goto out_nfserr;
1422
	*lenp = host_err;
L
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	err = 0;
out:
	return err;

out_nfserr:
1428
	err = nfserrno(host_err);
L
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	goto out;
}

/*
 * Create a symlink and look up its inode
 * N.B. After this call _both_ fhp and resfhp need an fh_put
 */
1436
__be32
L
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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;
1444 1445
	__be32		err, cerr;
	int		host_err;
L
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1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460
	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);
1461
	host_err = PTR_ERR(dnew);
L
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	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)
1473
			host_err = -ENOMEM;
L
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1474 1475 1476
		else {
			strncpy(path_alloced, path, plen);
			path_alloced[plen] = 0;
1477
			host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
L
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1478 1479 1480
			kfree(path_alloced);
		}
	} else
1481
		host_err = vfs_symlink(dentry->d_inode, dnew, path, mode);
L
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1482

1483
	if (!host_err) {
L
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1484
		if (EX_ISSYNC(fhp->fh_export))
1485 1486 1487
			host_err = nfsd_sync_dir(dentry);
	}
	err = nfserrno(host_err);
L
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	fh_unlock(fhp);

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

out_nfserr:
1497
	err = nfserrno(host_err);
L
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1498 1499 1500 1501 1502 1503 1504
	goto out;
}

/*
 * Create a hardlink
 * N.B. After this call _both_ ffhp and tfhp need an fh_put
 */
1505
__be32
L
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1506 1507 1508 1509 1510
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;
1511 1512
	__be32		err;
	int		host_err;
L
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1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527

	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
1528
	fh_lock_nested(ffhp, I_MUTEX_PARENT);
L
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1529 1530 1531 1532
	ddir = ffhp->fh_dentry;
	dirp = ddir->d_inode;

	dnew = lookup_one_len(name, ddir, len);
1533
	host_err = PTR_ERR(dnew);
L
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1534 1535 1536 1537 1538 1539
	if (IS_ERR(dnew))
		goto out_nfserr;

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

1540 1541
	host_err = vfs_link(dold, dirp, dnew);
	if (!host_err) {
L
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1542
		if (EX_ISSYNC(ffhp->fh_export)) {
1543
			err = nfserrno(nfsd_sync_dir(ddir));
L
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1544 1545
			write_inode_now(dest, 1);
		}
1546
		err = 0;
L
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1547
	} else {
1548
		if (host_err == -EXDEV && rqstp->rq_vers == 2)
L
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1549 1550
			err = nfserr_acces;
		else
1551
			err = nfserrno(host_err);
L
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1552 1553 1554
	}

	dput(dnew);
1555 1556
out_unlock:
	fh_unlock(ffhp);
L
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1557 1558 1559 1560
out:
	return err;

out_nfserr:
1561
	err = nfserrno(host_err);
1562
	goto out_unlock;
L
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1563 1564 1565 1566 1567 1568
}

/*
 * Rename a file
 * N.B. After this call _both_ ffhp and tfhp need an fh_put
 */
1569
__be32
L
Linus Torvalds 已提交
1570 1571 1572 1573 1574
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;
1575 1576
	__be32		err;
	int		host_err;
L
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1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591

	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;
1592
	if (ffhp->fh_export != tfhp->fh_export)
L
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1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606
		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);
1607
	host_err = PTR_ERR(odentry);
L
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1608 1609 1610
	if (IS_ERR(odentry))
		goto out_nfserr;

1611
	host_err = -ENOENT;
L
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1612 1613
	if (!odentry->d_inode)
		goto out_dput_old;
1614
	host_err = -EINVAL;
L
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1615 1616 1617 1618
	if (odentry == trap)
		goto out_dput_old;

	ndentry = lookup_one_len(tname, tdentry, tlen);
1619
	host_err = PTR_ERR(ndentry);
L
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1620 1621
	if (IS_ERR(ndentry))
		goto out_dput_old;
1622
	host_err = -ENOTEMPTY;
L
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1623 1624 1625 1626 1627 1628 1629
	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))) {
1630
			host_err = -EPERM;
L
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1631 1632
	} else
#endif
1633 1634 1635 1636 1637
	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);
L
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1638 1639 1640 1641 1642 1643 1644
	}

 out_dput_new:
	dput(ndentry);
 out_dput_old:
	dput(odentry);
 out_nfserr:
1645
	err = nfserrno(host_err);
L
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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
 */
1664
__be32
L
Linus Torvalds 已提交
1665 1666 1667 1668 1669
nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
				char *fname, int flen)
{
	struct dentry	*dentry, *rdentry;
	struct inode	*dirp;
1670 1671
	__be32		err;
	int		host_err;
L
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1672 1673 1674 1675 1676 1677 1678 1679

	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
1680
	fh_lock_nested(fhp, I_MUTEX_PARENT);
L
Linus Torvalds 已提交
1681 1682 1683 1684
	dentry = fhp->fh_dentry;
	dirp = dentry->d_inode;

	rdentry = lookup_one_len(fname, dentry, flen);
1685
	host_err = PTR_ERR(rdentry);
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Linus Torvalds 已提交
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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)) {
1702
			host_err = -EPERM;
L
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		} else
#endif
1705
		host_err = vfs_unlink(dirp, rdentry);
L
Linus Torvalds 已提交
1706
	} else { /* It's RMDIR */
1707
		host_err = vfs_rmdir(dirp, rdentry);
L
Linus Torvalds 已提交
1708 1709 1710 1711
	}

	dput(rdentry);

1712 1713 1714 1715
	if (host_err)
		goto out_nfserr;
	if (EX_ISSYNC(fhp->fh_export))
		host_err = nfsd_sync_dir(dentry);
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Linus Torvalds 已提交
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out_nfserr:
1718
	err = nfserrno(host_err);
1719 1720
out:
	return err;
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}

/*
 * Read entries from a directory.
 * The  NFSv3/4 verifier we ignore for now.
 */
1727
__be32
L
Linus Torvalds 已提交
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nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 
	     struct readdir_cd *cdp, encode_dent_fn func)
{
1731 1732
	__be32		err;
	int 		host_err;
L
Linus Torvalds 已提交
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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 */
1754 1755 1756 1757
		host_err = vfs_readdir(file, (filldir_t) func, cdp);
	} while (host_err >=0 && cdp->err == nfs_ok);
	if (host_err)
		err = nfserrno(host_err);
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Linus Torvalds 已提交
1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773
	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
 */
1774
__be32
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Linus Torvalds 已提交
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nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat)
{
1777
	__be32 err = fh_verify(rqstp, fhp, 0, MAY_NOP);
1778
	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.
 */
1786
__be32
L
Linus Torvalds 已提交
1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 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 1836 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
nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc)
{
	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)) {
			if (EX_RDONLY(exp) || IS_RDONLY(inode))
				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)
{
1867
	if (!raparml)
L
Linus Torvalds 已提交
1868 1869 1870
		return;
	dprintk("nfsd: freeing readahead buffers.\n");
	kfree(raparml);
1871
	raparml = NULL;
L
Linus Torvalds 已提交
1872 1873 1874 1875 1876 1877 1878 1879
}
/*
 * Initialize readahead param cache
 */
int
nfsd_racache_init(int cache_size)
{
	int	i;
1880 1881
	int	j = 0;
	int	nperbucket;
L
Linus Torvalds 已提交
1882

1883 1884

	if (raparml)
L
Linus Torvalds 已提交
1885
		return 0;
1886 1887
	if (cache_size < 2*RAPARM_HASH_SIZE)
		cache_size = 2*RAPARM_HASH_SIZE;
L
Linus Torvalds 已提交
1888 1889 1890 1891 1892
	raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL);

	if (raparml != NULL) {
		dprintk("nfsd: allocating %d readahead buffers.\n",
			cache_size);
1893 1894 1895 1896 1897
		for (i = 0 ; i < RAPARM_HASH_SIZE ; i++) {
			raparm_hash[i].pb_head = NULL;
			spin_lock_init(&raparm_hash[i].pb_lock);
		}
		nperbucket = cache_size >> RAPARM_HASH_BITS;
L
Linus Torvalds 已提交
1898 1899
		memset(raparml, 0, sizeof(struct raparms) * cache_size);
		for (i = 0; i < cache_size - 1; i++) {
1900 1901 1902 1903
			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
1904 1905 1906 1907 1908 1909 1910 1911 1912
		}
	} else {
		printk(KERN_WARNING
		       "nfsd: Could not allocate memory read-ahead cache.\n");
		return -ENOMEM;
	}
	nfsdstats.ra_size = cache_size;
	return 0;
}
1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923

#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;

1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934
	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:
1935 1936 1937
		return ERR_PTR(-EOPNOTSUPP);
	}

1938 1939 1940
	size = nfsd_getxattr(fhp->fh_dentry, name, &value);
	if (size < 0)
		return ERR_PTR(size);
1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960

	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:
1961
			name = POSIX_ACL_XATTR_ACCESS;
1962 1963
			break;
		case ACL_TYPE_DEFAULT:
1964
			name = POSIX_ACL_XATTR_DEFAULT;
1965 1966 1967 1968 1969 1970
			break;
		default:
			return -EOPNOTSUPP;
	}

	if (acl && acl->a_count) {
1971
		size = posix_acl_xattr_size(acl->a_count);
1972 1973 1974
		value = kmalloc(size, GFP_KERNEL);
		if (!value)
			return -ENOMEM;
1975 1976
		error = posix_acl_to_xattr(acl, value, size);
		if (error < 0)
1977
			goto getout;
1978
		size = error;
1979 1980 1981 1982
	} else
		size = 0;

	if (size)
1983
		error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
1984 1985 1986 1987
	else {
		if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
			error = 0;
		else {
1988
			error = vfs_removexattr(fhp->fh_dentry, name);
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
			if (error == -ENODATA)
				error = 0;
		}
	}

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