示例#1
0
/*
 * if valid returns 1, otherwise 0.
 */
static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
	int valid, err;
	unsigned int sigen;
	unsigned char do_udba;
	struct super_block *sb;
	struct inode *inode;

	err = -EINVAL;
	sb = dentry->d_sb;
	inode = dentry->d_inode;
	aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW);
	sigen = au_sigen(sb);
	if (au_digen(dentry) != sigen) {
		AuDebugOn(IS_ROOT(dentry));
		if (inode)
			err = au_reval_dpath(dentry, sigen);
		if (unlikely(err))
			goto out_dgrade;
		AuDebugOn(au_digen(dentry) != sigen);
	}
	if (inode && au_iigen(inode) != sigen) {
		AuDebugOn(IS_ROOT(dentry));
		err = au_refresh_hinode(inode, dentry);
		if (unlikely(err))
			goto out_dgrade;
		AuDebugOn(au_iigen(inode) != sigen);
	}
	di_downgrade_lock(dentry, AuLock_IR);

	AuDebugOn(au_digen(dentry) != sigen);
	AuDebugOn(inode && au_iigen(inode) != sigen);
	err = -EINVAL;
	do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
	if (do_udba && inode) {
		aufs_bindex_t bstart = au_ibstart(inode);

		if (bstart >= 0
		    && au_test_higen(inode, au_h_iptr(inode, bstart)))
			goto out;
	}

	err = h_d_revalidate(dentry, inode, nd, do_udba);
	if (unlikely(!err && do_udba && au_dbstart(dentry) < 0))
		/* both of real entry and whiteout found */
		err = -EIO;
	goto out;

 out_dgrade:
	di_downgrade_lock(dentry, AuLock_IR);
 out:
	aufs_read_unlock(dentry, AuLock_IR);
	AuTraceErr(err);
	valid = !err;
	if (!valid)
		AuDbg("%.*s invalid\n", AuDLNPair(dentry));
	return valid;
}
示例#2
0
/* common function to regular file and dir */
int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
			  int wlock)
{
	int err;
	unsigned int sigen, figen;
	aufs_bindex_t bstart;
	unsigned char pseudo_link;
	struct dentry *dentry;
	struct inode *inode;

	err = 0;
	dentry = file->f_dentry;
	inode = dentry->d_inode;
	AuDebugOn(au_special_file(inode->i_mode));
	sigen = au_sigen(dentry->d_sb);
	fi_write_lock(file);
	figen = au_figen(file);
	di_write_lock_child(dentry);
	bstart = au_dbstart(dentry);
	pseudo_link = (bstart != au_ibstart(inode));
	if (sigen == figen && !pseudo_link && au_fbstart(file) == bstart) {
		if (!wlock) {
			di_downgrade_lock(dentry, AuLock_IR);
			fi_downgrade_lock(file);
		}
		goto out; /* success */
	}

	AuDbg("sigen %d, figen %d\n", sigen, figen);
	if (sigen != au_digen(dentry)
	    || sigen != au_iigen(inode)) {
		err = au_reval_dpath(dentry, sigen);
		if (unlikely(err < 0))
			goto out;
		AuDebugOn(au_digen(dentry) != sigen
			  || au_iigen(inode) != sigen);
	}

	err = refresh_file(file, reopen);
	if (!err) {
		if (!wlock) {
			di_downgrade_lock(dentry, AuLock_IR);
			fi_downgrade_lock(file);
		}
	} else {
		di_write_unlock(dentry);
		fi_write_unlock(file);
	}

out:
	return err;
}
示例#3
0
/*
 * prepare the @file for writing.
 */
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
	int err;
	aufs_bindex_t bstart, bcpup, dbstart;
	struct dentry *dentry, *parent, *h_dentry;
	struct inode *h_inode, *inode;
	struct super_block *sb;
	struct file *h_file;

	dentry = file->f_dentry;
	sb = dentry->d_sb;
	inode = dentry->d_inode;
	AuDebugOn(au_special_file(inode->i_mode));
	bstart = au_fbstart(file);
	err = au_test_ro(sb, bstart, inode);
	if (!err && (au_hf_top(file)->f_mode & FMODE_WRITE)) {
		err = au_pin(pin, dentry, bstart, AuOpt_UDBA_NONE, /*flags*/0);
		goto out;
	}

	/* need to cpup or reopen */
	parent = dget_parent(dentry);
	di_write_lock_parent(parent);
	err = AuWbrCopyup(au_sbi(sb), dentry);
	bcpup = err;
	if (unlikely(err < 0))
		goto out_dgrade;
	err = 0;

	if (!d_unhashed(dentry) && !au_h_dptr(parent, bcpup)) {
		err = au_cpup_dirs(dentry, bcpup);
		if (unlikely(err))
			goto out_dgrade;
	}

	err = au_pin(pin, dentry, bcpup, AuOpt_UDBA_NONE,
		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
	if (unlikely(err))
		goto out_dgrade;

	h_dentry = au_hf_top(file)->f_dentry;
	h_inode = h_dentry->d_inode;
	dbstart = au_dbstart(dentry);
	if (dbstart <= bcpup) {
		h_dentry = au_h_dptr(dentry, bcpup);
		AuDebugOn(!h_dentry);
		h_inode = h_dentry->d_inode;
		AuDebugOn(!h_inode);
		bstart = bcpup;
	}

	if (dbstart <= bcpup		/* just reopen */
	    || !d_unhashed(dentry)	/* copyup and reopen */
		) {
		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
		h_file = au_h_open_pre(dentry, bstart);
		if (IS_ERR(h_file)) {
			err = PTR_ERR(h_file);
			h_file = NULL;
		} else {
			di_downgrade_lock(parent, AuLock_IR);
			if (dbstart > bcpup)
				err = au_sio_cpup_simple(dentry, bcpup, len,
							 AuCpup_DTIME);
			if (!err)
				err = au_reopen_nondir(file);
		}
		mutex_unlock(&h_inode->i_mutex);
		au_h_open_post(dentry, bstart, h_file);
	} else {			/* copyup as wh and reopen */
		/*
		 * since writable hfsplus branch is not supported,
		 * h_open_pre/post() are unnecessary.
		 */
		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
		err = au_ready_to_write_wh(file, len, bcpup);
		di_downgrade_lock(parent, AuLock_IR);
		mutex_unlock(&h_inode->i_mutex);
	}

	if (!err) {
		au_pin_set_parent_lflag(pin, /*lflag*/0);
		goto out_dput; /* success */
	}
	au_unpin(pin);
	goto out_unlock;

out_dgrade:
	di_downgrade_lock(parent, AuLock_IR);
out_unlock:
	di_read_unlock(parent, AuLock_IR);
out_dput:
	dput(parent);
out:
	return err;
}
示例#4
0
/*
 * if valid returns 1, otherwise 0.
 */
static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
	int valid, err;
	unsigned int sigen;
	unsigned char do_udba;
	struct super_block *sb;
	struct inode *inode;

	valid = 0;
	if (unlikely(!au_di(dentry)))
		goto out;

	valid = 1;
	sb = dentry->d_sb;
	inode = dentry->d_inode;
	/*
	 * todo: very ugly
	 * i_mutex of parent dir may be held,
	 * but we should not return 'invalid' due to busy.
	 */
	err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM);
	if (unlikely(err)) {
		valid = err;
		AuTraceErr(err);
		goto out;
	}
	if (unlikely(au_dbrange_test(dentry))) {
		err = -EINVAL;
		AuTraceErr(err);
		goto out_dgrade;
	}

	sigen = au_sigen(sb);
	if (au_digen_test(dentry, sigen)) {
		AuDebugOn(IS_ROOT(dentry));
		err = au_reval_dpath(dentry, sigen);
		if (unlikely(err)) {
			AuTraceErr(err);
			goto out_dgrade;
		}
	}
	di_downgrade_lock(dentry, AuLock_IR);

	err = -EINVAL;
	if (inode && (IS_DEADDIR(inode) || !inode->i_nlink))
		goto out_inval;

	do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
	if (do_udba && inode) {
		aufs_bindex_t bstart = au_ibstart(inode);
		struct inode *h_inode;

		if (bstart >= 0) {
			h_inode = au_h_iptr(inode, bstart);
			if (h_inode && au_test_higen(inode, h_inode))
				goto out_inval;
		}
	}

	err = h_d_revalidate(dentry, inode, nd, do_udba);
	if (unlikely(!err && do_udba && au_dbstart(dentry) < 0)) {
		err = -EIO;
		AuDbg("both of real entry and whiteout found, %.*s, err %d\n",
		      AuDLNPair(dentry), err);
	}
	goto out_inval;

out_dgrade:
	di_downgrade_lock(dentry, AuLock_IR);
out_inval:
	aufs_read_unlock(dentry, AuLock_IR);
	AuTraceErr(err);
	valid = !err;
out:
	if (!valid) {
		AuDbg("%.*s invalid, %d\n", AuDLNPair(dentry), valid);
		d_drop(dentry);
	}
	return valid;
}
示例#5
0
文件: dentry.c 项目: ammubhave/bargud
/*
 * if valid returns 1, otherwise 0.
 */
static int aufs_d_revalidate(struct dentry *dentry, unsigned int flags)
{
	int valid, err;
	unsigned int sigen;
	unsigned char do_udba;
	struct super_block *sb;
	struct inode *inode;

	/* todo: support rcu-walk? */
	if (flags & LOOKUP_RCU)
		return -ECHILD;

	valid = 0;
	if (unlikely(!au_di(dentry)))
		goto out;

	valid = 1;
	sb = dentry->d_sb;
	/*
	 * todo: very ugly
	 * i_mutex of parent dir may be held,
	 * but we should not return 'invalid' due to busy.
	 */
	err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM);
	if (unlikely(err)) {
		valid = err;
		AuTraceErr(err);
		goto out;
	}
	inode = NULL;
	if (d_really_is_positive(dentry))
		inode = d_inode(dentry);
	if (unlikely(inode && is_bad_inode(inode))) {
		err = -EINVAL;
		AuTraceErr(err);
		goto out_dgrade;
	}
	if (unlikely(au_dbrange_test(dentry))) {
		err = -EINVAL;
		AuTraceErr(err);
		goto out_dgrade;
	}

	sigen = au_sigen(sb);
	if (au_digen_test(dentry, sigen)) {
		AuDebugOn(IS_ROOT(dentry));
		err = au_reval_dpath(dentry, sigen);
		if (unlikely(err)) {
			AuTraceErr(err);
			goto out_dgrade;
		}
	}
	di_downgrade_lock(dentry, AuLock_IR);

	err = -EINVAL;
	if (!(flags & (LOOKUP_OPEN | LOOKUP_EMPTY))
	    && inode
	    && !(inode->i_state && I_LINKABLE)
	    && (IS_DEADDIR(inode) || !inode->i_nlink))
		goto out_inval;

	do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
	if (do_udba && inode) {
		aufs_bindex_t bstart = au_ibstart(inode);
		struct inode *h_inode;

		if (bstart >= 0) {
			h_inode = au_h_iptr(inode, bstart);
			if (h_inode && au_test_higen(inode, h_inode))
				goto out_inval;
		}
	}

	err = h_d_revalidate(dentry, inode, flags, do_udba);
	if (unlikely(!err && do_udba && au_dbstart(dentry) < 0)) {
		err = -EIO;
		AuDbg("both of real entry and whiteout found, %p, err %d\n",
		      dentry, err);
	}
	goto out_inval;

out_dgrade:
	di_downgrade_lock(dentry, AuLock_IR);
out_inval:
	aufs_read_unlock(dentry, AuLock_IR);
	AuTraceErr(err);
	valid = !err;
out:
	if (!valid) {
		AuDbg("%pd invalid, %d\n", dentry, valid);
		d_drop(dentry);
	}
	return valid;
}
/*
 * test if the branch is deletable or not.
 */
static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
			    unsigned int sigen, const unsigned int verbose)
{
	int err, i, j, ndentry;
	aufs_bindex_t bstart, bend;
	struct au_dcsub_pages dpages;
	struct au_dpage *dpage;
	struct dentry *d;

	err = au_dpages_init(&dpages, GFP_NOFS);
	if (unlikely(err))
		goto out;
	err = au_dcsub_pages(&dpages, root, NULL, NULL);
	if (unlikely(err))
		goto out_dpages;

	for (i = 0; !err && i < dpages.ndpage; i++) {
		dpage = dpages.dpages + i;
		ndentry = dpage->ndentry;
		for (j = 0; !err && j < ndentry; j++) {
			d = dpage->dentries[j];
			AuDebugOn(!atomic_read(&d->d_count));
			if (!au_digen_test(d, sigen)) {
				di_read_lock_child(d, AuLock_IR);
				if (unlikely(au_dbrange_test(d))) {
					di_read_unlock(d, AuLock_IR);
					continue;
				}
			} else {
				di_write_lock_child(d);
				if (unlikely(au_dbrange_test(d))) {
					di_write_unlock(d);
					continue;
				}
				err = au_reval_dpath(d, sigen);
				if (!err)
					di_downgrade_lock(d, AuLock_IR);
				else {
					di_write_unlock(d);
					break;
				}
			}

			/* AuDbgDentry(d); */
			bstart = au_dbstart(d);
			bend = au_dbend(d);
			if (bstart <= bindex
			    && bindex <= bend
			    && au_h_dptr(d, bindex)
			    && au_test_dbusy(d, bstart, bend)) {
				err = -EBUSY;
				AuVerbose(verbose, "busy %.*s\n", AuDLNPair(d));
				AuDbgDentry(d);
			}
			di_read_unlock(d, AuLock_IR);
		}
	}

out_dpages:
	au_dpages_free(&dpages);
out:
	return err;
}
示例#7
0
int au_do_open(struct inode *inode, struct file *file,
	       int (*open)(struct file *file, int flags))
{
	int err, coo;
	struct dentry *dentry;
	struct super_block *sb;
	aufs_bindex_t bstart;
	struct inode *h_dir, *dir;

	dentry = file->f_dentry;
	LKTRTrace("i%lu, %.*s\n", inode->i_ino, DLNPair(dentry));

	sb = dentry->d_sb;
	si_read_lock(sb);
	coo = 0;
#if 0
	switch (au_flag_test_coo(sb)) {
	case AuFlag_COO_LEAF:
		coo = !S_ISDIR(inode->i_mode);
		break;
	case AuFlag_COO_ALL:
		coo = 1;
		break;
	}
#endif
	err = au_init_finfo(file);
	//if (LktrCond) {fi_write_unlock(file); fin_finfo(file); err = -1;}
	if (unlikely(err))
		goto out;

	if (!coo) {
		di_read_lock_child(dentry, AUFS_I_RLOCK);
		bstart = dbstart(dentry);
	} else {
		di_write_lock_child(dentry);
		bstart = dbstart(dentry);
		if (test_ro(sb, bstart, dentry->d_inode)) {
			err = do_coo(dentry, bstart);
			if (err) {
				di_write_unlock(dentry);
				goto out_finfo;
			}
			bstart = dbstart(dentry);
		}
		di_downgrade_lock(dentry, AUFS_I_RLOCK);
	}

	// todo: remove this extra locks
	dir = dentry->d_parent->d_inode;
	if (!IS_ROOT(dentry))
		ii_read_lock_parent(dir);
	h_dir = au_h_iptr_i(dir, bstart);
	hdir_lock(h_dir, dir, bstart);
	err = open(file, file->f_flags);
	//if (LktrCond) err = -1;
	hdir_unlock(h_dir, dir, bstart);
	if (!IS_ROOT(dentry))
		ii_read_unlock(dir);
	di_read_unlock(dentry, AUFS_I_RLOCK);

 out_finfo:
	fi_write_unlock(file);
	if (unlikely(err))
		au_fin_finfo(file);
	//DbgFile(file);
 out:
	si_read_unlock(sb);
	TraceErr(err);
	return err;
}
示例#8
0
文件: file.c 项目: bojosos/linux
/*
 * prepare the @file for writing.
 */
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
	int err;
	aufs_bindex_t bstart, bcpup;
	struct dentry *dentry, *parent, *h_dentry;
	struct inode *h_inode, *inode;
	struct super_block *sb;

	dentry = file->f_dentry;
	sb = dentry->d_sb;
	inode = dentry->d_inode;
	AuDebugOn(au_special_file(inode->i_mode));
	bstart = au_fbstart(file);
	err = au_test_ro(sb, bstart, inode);
	if (!err && (au_h_fptr(file, bstart)->f_mode & FMODE_WRITE)) {
		err = au_pin(pin, dentry, bstart, AuOpt_UDBA_NONE, /*flags*/0);
		goto out;
	}

	/* need to cpup */
	parent = dget_parent(dentry);
	di_write_lock_parent(parent);
	err = AuWbrCopyup(au_sbi(sb), dentry);
	bcpup = err;
	if (unlikely(err < 0))
		goto out_dgrade;
	err = 0;

	if (!au_h_dptr(parent, bcpup)) {
		err = au_cpup_dirs(dentry, bcpup);
		if (unlikely(err))
			goto out_dgrade;
	}

	err = au_pin(pin, dentry, bcpup, AuOpt_UDBA_NONE,
		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
	if (unlikely(err))
		goto out_dgrade;

	h_dentry = au_h_fptr(file, bstart)->f_dentry;
	h_inode = h_dentry->d_inode;
	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
	if (d_unhashed(dentry) /* || d_unhashed(h_dentry) */
	    /* || !h_inode->i_nlink */) {
		err = au_ready_to_write_wh(file, len, bcpup);
		di_downgrade_lock(parent, AuLock_IR);
	} else {
		di_downgrade_lock(parent, AuLock_IR);
		if (!au_h_dptr(dentry, bcpup))
			err = au_sio_cpup_simple(dentry, bcpup, len,
						 AuCpup_DTIME);
		if (!err)
			err = au_reopen_nondir(file);
	}
	mutex_unlock(&h_inode->i_mutex);

	if (!err) {
		au_pin_set_parent_lflag(pin, /*lflag*/0);
		goto out_dput; /* success */
	}
	au_unpin(pin);
	goto out_unlock;

 out_dgrade:
	di_downgrade_lock(parent, AuLock_IR);
 out_unlock:
	di_read_unlock(parent, AuLock_IR);
 out_dput:
	dput(parent);
 out:
	return err;
}
示例#9
0
文件: file.c 项目: marceleng/linux
static int au_ready_to_write_wh(struct file *file, loff_t len,
				aufs_bindex_t bcpup, struct au_pin *pin)
{
	int err;
	struct inode *inode, *h_inode;
	struct dentry *h_dentry, *hi_wh;
	struct au_cp_generic cpg = {
		.dentry	= file->f_dentry,
		.bdst	= bcpup,
		.bsrc	= -1,
		.len	= len,
		.pin	= pin
	};

	au_update_dbstart(cpg.dentry);
	inode = cpg.dentry->d_inode;
	h_inode = NULL;
	if (au_dbstart(cpg.dentry) <= bcpup
	    && au_dbend(cpg.dentry) >= bcpup) {
		h_dentry = au_h_dptr(cpg.dentry, bcpup);
		if (h_dentry)
			h_inode = h_dentry->d_inode;
	}
	hi_wh = au_hi_wh(inode, bcpup);
	if (!hi_wh && !h_inode)
		err = au_sio_cpup_wh(&cpg, file);
	else
		/* already copied-up after unlink */
		err = au_reopen_wh(file, bcpup, hi_wh);

	if (!err
	    && inode->i_nlink > 1
	    && au_opt_test(au_mntflags(cpg.dentry->d_sb), PLINK))
		au_plink_append(inode, bcpup, au_h_dptr(cpg.dentry, bcpup));

	return err;
}

/*
 * prepare the @file for writing.
 */
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
	int err;
	aufs_bindex_t dbstart;
	struct dentry *parent, *h_dentry;
	struct inode *inode;
	struct super_block *sb;
	struct file *h_file;
	struct au_cp_generic cpg = {
		.dentry	= file->f_dentry,
		.bdst	= -1,
		.bsrc	= -1,
		.len	= len,
		.pin	= pin,
		.flags	= AuCpup_DTIME
	};

	sb = cpg.dentry->d_sb;
	inode = cpg.dentry->d_inode;
	AuDebugOn(au_special_file(inode->i_mode));
	cpg.bsrc = au_fbstart(file);
	err = au_test_ro(sb, cpg.bsrc, inode);
	if (!err && (au_hf_top(file)->f_mode & FMODE_WRITE)) {
		err = au_pin(pin, cpg.dentry, cpg.bsrc, AuOpt_UDBA_NONE,
			     /*flags*/0);
		goto out;
	}

	/* need to cpup or reopen */
	parent = dget_parent(cpg.dentry);
	di_write_lock_parent(parent);
	err = AuWbrCopyup(au_sbi(sb), cpg.dentry);
	cpg.bdst = err;
	if (unlikely(err < 0))
		goto out_dgrade;
	err = 0;

	if (!d_unhashed(cpg.dentry) && !au_h_dptr(parent, cpg.bdst)) {
		err = au_cpup_dirs(cpg.dentry, cpg.bdst);
		if (unlikely(err))
			goto out_dgrade;
	}

	err = au_pin(pin, cpg.dentry, cpg.bdst, AuOpt_UDBA_NONE,
		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
	if (unlikely(err))
		goto out_dgrade;

	h_dentry = au_hf_top(file)->f_dentry;
	dbstart = au_dbstart(cpg.dentry);
	if (dbstart <= cpg.bdst) {
		h_dentry = au_h_dptr(cpg.dentry, cpg.bdst);
		AuDebugOn(!h_dentry);
		cpg.bsrc = cpg.bdst;
	}

	if (dbstart <= cpg.bdst		/* just reopen */
	    || !d_unhashed(cpg.dentry)	/* copyup and reopen */
		) {
		h_file = au_h_open_pre(cpg.dentry, cpg.bsrc, /*force_wr*/0);
		if (IS_ERR(h_file))
			err = PTR_ERR(h_file);
		else {
			di_downgrade_lock(parent, AuLock_IR);
			if (dbstart > cpg.bdst)
				err = au_sio_cpup_simple(&cpg);
			if (!err)
				err = au_reopen_nondir(file);
			au_h_open_post(cpg.dentry, cpg.bsrc, h_file);
		}
	} else {			/* copyup as wh and reopen */
		/*
		 * since writable hfsplus branch is not supported,
		 * h_open_pre/post() are unnecessary.
		 */
		err = au_ready_to_write_wh(file, len, cpg.bdst, pin);
		di_downgrade_lock(parent, AuLock_IR);
	}

	if (!err) {
		au_pin_set_parent_lflag(pin, /*lflag*/0);
		goto out_dput; /* success */
	}
	au_unpin(pin);
	goto out_unlock;

out_dgrade:
	di_downgrade_lock(parent, AuLock_IR);
out_unlock:
	di_read_unlock(parent, AuLock_IR);
out_dput:
	dput(parent);
out:
	return err;
}

/* ---------------------------------------------------------------------- */

int au_do_flush(struct file *file, fl_owner_t id,
		int (*flush)(struct file *file, fl_owner_t id))
{
	int err;
	struct super_block *sb;
	struct inode *inode;

	inode = file_inode(file);
	sb = inode->i_sb;
	si_noflush_read_lock(sb);
	fi_read_lock(file);
	ii_read_lock_child(inode);

	err = flush(file, id);
	au_cpup_attr_timesizes(inode);

	ii_read_unlock(inode);
	fi_read_unlock(file);
	si_read_unlock(sb);
	return err;
}
示例#10
0
static int au_cmoo(struct dentry *dentry)
{
	int err, cmoo;
	unsigned int udba;
	struct path h_path;
	struct au_pin pin;
	struct au_cp_generic cpg = {
		.dentry	= dentry,
		.bdst	= -1,
		.bsrc	= -1,
		.len	= -1,
		.pin	= &pin,
		.flags	= AuCpup_DTIME | AuCpup_HOPEN
	};
	struct inode *inode, *delegated;
	struct super_block *sb;
	struct au_sbinfo *sbinfo;
	struct au_fhsm *fhsm;
	pid_t pid;
	struct au_branch *br;
	struct dentry *parent;
	struct au_hinode *hdir;

	DiMustWriteLock(dentry);
	inode = dentry->d_inode;
	IiMustWriteLock(inode);

	err = 0;
	if (IS_ROOT(dentry))
		goto out;
	cpg.bsrc = au_dbstart(dentry);
	if (!cpg.bsrc)
		goto out;

	sb = dentry->d_sb;
	sbinfo = au_sbi(sb);
	fhsm = &sbinfo->si_fhsm;
	pid = au_fhsm_pid(fhsm);
	if (pid
	    && (current->pid == pid
		|| current->real_parent->pid == pid))
		goto out;

	br = au_sbr(sb, cpg.bsrc);
	cmoo = au_br_cmoo(br->br_perm);
	if (!cmoo)
		goto out;
	if (!S_ISREG(inode->i_mode))
		cmoo &= AuBrAttr_COO_ALL;
	if (!cmoo)
		goto out;

	parent = dget_parent(dentry);
	di_write_lock_parent(parent);
	err = au_wbr_do_copyup_bu(dentry, cpg.bsrc - 1);
	cpg.bdst = err;
	if (unlikely(err < 0)) {
		err = 0;	/* there is no upper writable branch */
		goto out_dgrade;
	}
	AuDbg("bsrc %d, bdst %d\n", cpg.bsrc, cpg.bdst);

	/* do not respect the coo attrib for the target branch */
	err = au_cpup_dirs(dentry, cpg.bdst);
	if (unlikely(err))
		goto out_dgrade;

	di_downgrade_lock(parent, AuLock_IR);
	udba = au_opt_udba(sb);
	err = au_pin(&pin, dentry, cpg.bdst, udba,
		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
	if (unlikely(err))
		goto out_parent;

	err = au_sio_cpup_simple(&cpg);
	au_unpin(&pin);
	if (unlikely(err))
		goto out_parent;
	if (!(cmoo & AuBrWAttr_MOO))
		goto out_parent; /* success */

	err = au_pin(&pin, dentry, cpg.bsrc, udba,
		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
	if (unlikely(err))
		goto out_parent;

	h_path.mnt = au_br_mnt(br);
	h_path.dentry = au_h_dptr(dentry, cpg.bsrc);
	hdir = au_hi(parent->d_inode, cpg.bsrc);
	delegated = NULL;
	err = vfsub_unlink(hdir->hi_inode, &h_path, &delegated, /*force*/1);
	au_unpin(&pin);
	/* todo: keep h_dentry or not? */
	if (unlikely(err == -EWOULDBLOCK)) {
		pr_warn("cannot retry for NFSv4 delegation"
			" for an internal unlink\n");
		iput(delegated);
	}
	if (unlikely(err)) {
		pr_err("unlink %pd after coo failed (%d), ignored\n",
		       dentry, err);
		err = 0;
	}
	goto out_parent; /* success */

out_dgrade:
	di_downgrade_lock(parent, AuLock_IR);
out_parent:
	di_read_unlock(parent, AuLock_IR);
	dput(parent);
out:
	AuTraceErr(err);
	return err;
}

int au_do_open(struct file *file, int (*open)(struct file *file, int flags),
	       struct au_fidir *fidir)
{
	int err;
	struct dentry *dentry;
	struct au_finfo *finfo;

	err = au_finfo_init(file, fidir);
	if (unlikely(err))
		goto out;

	dentry = file->f_path.dentry;
	di_write_lock_child(dentry);
	err = au_cmoo(dentry);
	di_downgrade_lock(dentry, AuLock_IR);
	if (!err)
		err = open(file, vfsub_file_flags(file));
	di_read_unlock(dentry, AuLock_IR);

	finfo = au_fi(file);
	if (!err) {
		finfo->fi_file = file;
		au_sphl_add(&finfo->fi_hlist,
			    &au_sbi(file->f_path.dentry->d_sb)->si_files);
	}
	fi_write_unlock(file);
	if (unlikely(err)) {
		finfo->fi_hdir = NULL;
		au_finfo_fin(file);
	}

out:
	return err;
}