static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
					struct file *f,
					int (*open)(struct inode *, struct file *),
					const struct cred *cred)
{
	static const struct file_operations empty_fops = {};
	struct inode *inode;
	int error;

	f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
				FMODE_PREAD | FMODE_PWRITE;

	if (unlikely(f->f_flags & O_PATH))
		f->f_mode = FMODE_PATH;

	inode = dentry->d_inode;
	if (f->f_mode & FMODE_WRITE) {
		error = __get_file_write_access(inode, mnt);
		if (error)
			goto cleanup_file;
		if (!special_file(inode->i_mode))
			file_take_write(f);
	}

	f->f_mapping = inode->i_mapping;
	f->f_path.dentry = dentry;
	f->f_path.mnt = mnt;
	f->f_pos = 0;
	file_sb_list_add(f, inode->i_sb);

	if (unlikely(f->f_mode & FMODE_PATH)) {
		f->f_op = &empty_fops;
		return f;
	}

	f->f_op = fops_get(inode->i_fop);

	error = security_dentry_open(f, cred);
	if (error)
		goto cleanup_all;

	error = break_lease(inode, f->f_flags);
	if (error)
		goto cleanup_all;

	if (!open && f->f_op)
		open = f->f_op->open;
	if (open) {
		error = open(inode, f);
		if (error)
			goto cleanup_all;
	}
	if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
		i_readcount_inc(inode);

	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);

	/* NB: we're sure to have correct a_ops only after f_op->open */
	if (f->f_flags & O_DIRECT) {
		if (!f->f_mapping->a_ops ||
		    ((!f->f_mapping->a_ops->direct_IO) &&
		    (!f->f_mapping->a_ops->get_xip_mem))) {
			fput(f);
			f = ERR_PTR(-EINVAL);
		}
	}

	return f;

cleanup_all:
	fops_put(f->f_op);
	if (f->f_mode & FMODE_WRITE) {
		put_write_access(inode);
		if (!special_file(inode->i_mode)) {
			/*
			 * We don't consider this a real
			 * mnt_want/drop_write() pair
			 * because it all happenend right
			 * here, so just reset the state.
			 */
			file_reset_write(f);
			mnt_drop_write(mnt);
		}
	}
	file_sb_list_del(f);
	f->f_path.dentry = NULL;
	f->f_path.mnt = NULL;
cleanup_file:
	put_filp(f);
	dput(dentry);
	mntput(mnt);
	return ERR_PTR(error);
}
Example #2
0
/*
 * Set various file attributes.
 * N.B. After this call fhp needs an fh_put
 */
__be32
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;
	__be32		err;
	int		host_err;
	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);
	if (err)
		goto out;

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

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

	if (!iap->ia_valid)
		goto out;

	/* 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.
		 */
		host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
		if (host_err == -EWOULDBLOCK)
			host_err = -ETIMEDOUT;
		if (host_err) /* ENOMEM or EWOULDBLOCK */
			goto out_nfserr;

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

		size_change = 1;
		host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
		if (host_err) {
			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);
		host_err = notify_change(dentry, iap);
		err = nfserrno(host_err);
		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:
	err = nfserrno(host_err);
	goto out;
}
Example #3
0
static long do_sys_truncate(const char __user *pathname, loff_t length)
{
	struct path path;
	struct inode *inode;
	int error;

	error = -EINVAL;
	if (length < 0)	/* sorry, but loff_t says... */
		goto out;

	error = user_path(pathname, &path);
	if (error)
		goto out;
	inode = path.dentry->d_inode;

	/* For directories it's -EISDIR, for other non-regulars - -EINVAL */
	error = -EISDIR;
	if (S_ISDIR(inode->i_mode))
		goto dput_and_out;

	error = -EINVAL;
	if (!S_ISREG(inode->i_mode))
		goto dput_and_out;

	error = mnt_want_write(path.mnt);
	if (error)
		goto dput_and_out;

	error = inode_permission(inode, MAY_WRITE);
	if (error)
		goto mnt_drop_write_and_out;

	error = -EPERM;
	if (IS_APPEND(inode))
		goto mnt_drop_write_and_out;

	error = get_write_access(inode);
	if (error)
		goto mnt_drop_write_and_out;

	/*
	 * Make sure that there are no leases.  get_write_access() protects
	 * against the truncate racing with a lease-granting setlease().
	 */
	error = break_lease(inode, O_WRONLY);
	if (error)
		goto put_write_and_out;

	error = locks_verify_truncate(inode, NULL, length);
	if (!error)
		error = security_path_truncate(&path);
	if (!error)
		error = do_truncate(path.dentry, length, 0, NULL);

put_write_and_out:
	put_write_access(inode);
mnt_drop_write_and_out:
	mnt_drop_write(path.mnt);
dput_and_out:
	path_put(&path);
out:
	return error;
}
Example #4
0
static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct page *page = vmf->page;
	struct inode *inode = file_inode(vma->vm_file);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_alloc_parms ap = { .aflags = 0, };
	unsigned long last_index;
	u64 pos = page->index << PAGE_CACHE_SHIFT;
	unsigned int data_blocks, ind_blocks, rblocks;
	struct gfs2_holder gh;
	loff_t size;
	int ret;

	sb_start_pagefault(inode->i_sb);

	/* Update file times before taking page lock */
	file_update_time(vma->vm_file);

	ret = get_write_access(inode);
	if (ret)
		goto out;

	ret = gfs2_rs_alloc(ip);
	if (ret)
		goto out_write_access;

	gfs2_size_hint(vma->vm_file, pos, PAGE_CACHE_SIZE);

	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	ret = gfs2_glock_nq(&gh);
	if (ret)
		goto out_uninit;

	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
	set_bit(GIF_SW_PAGED, &ip->i_flags);

	if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE)) {
		lock_page(page);
		if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
			ret = -EAGAIN;
			unlock_page(page);
		}
		goto out_unlock;
	}

	ret = gfs2_rindex_update(sdp);
	if (ret)
		goto out_unlock;

	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
	ap.target = data_blocks + ind_blocks;
	ret = gfs2_quota_lock_check(ip, &ap);
	if (ret)
		goto out_unlock;
	ret = gfs2_inplace_reserve(ip, &ap);
	if (ret)
		goto out_quota_unlock;

	rblocks = RES_DINODE + ind_blocks;
	if (gfs2_is_jdata(ip))
		rblocks += data_blocks ? data_blocks : 1;
	if (ind_blocks || data_blocks) {
		rblocks += RES_STATFS + RES_QUOTA;
		rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
	}
	ret = gfs2_trans_begin(sdp, rblocks, 0);
	if (ret)
		goto out_trans_fail;

	lock_page(page);
	ret = -EINVAL;
	size = i_size_read(inode);
	last_index = (size - 1) >> PAGE_CACHE_SHIFT;
	/* Check page index against inode size */
	if (size == 0 || (page->index > last_index))
		goto out_trans_end;

	ret = -EAGAIN;
	/* If truncated, we must retry the operation, we may have raced
	 * with the glock demotion code.
	 */
	if (!PageUptodate(page) || page->mapping != inode->i_mapping)
		goto out_trans_end;

	/* Unstuff, if required, and allocate backing blocks for page */
	ret = 0;
	if (gfs2_is_stuffed(ip))
		ret = gfs2_unstuff_dinode(ip, page);
	if (ret == 0)
		ret = gfs2_allocate_page_backing(page);

out_trans_end:
	if (ret)
		unlock_page(page);
	gfs2_trans_end(sdp);
out_trans_fail:
	gfs2_inplace_release(ip);
out_quota_unlock:
	gfs2_quota_unlock(ip);
out_unlock:
	gfs2_glock_dq(&gh);
out_uninit:
	gfs2_holder_uninit(&gh);
	if (ret == 0) {
		set_page_dirty(page);
		wait_for_stable_page(page);
	}
out_write_access:
	put_write_access(inode);
out:
	sb_end_pagefault(inode->i_sb);
	return block_page_mkwrite_return(ret);
}

static const struct vm_operations_struct gfs2_vm_ops = {
	.fault = filemap_fault,
	.map_pages = filemap_map_pages,
	.page_mkwrite = gfs2_page_mkwrite,
};

/**
 * gfs2_mmap -
 * @file: The file to map
 * @vma: The VMA which described the mapping
 *
 * There is no need to get a lock here unless we should be updating
 * atime. We ignore any locking errors since the only consequence is
 * a missed atime update (which will just be deferred until later).
 *
 * Returns: 0
 */

static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);

	if (!(file->f_flags & O_NOATIME) &&
	    !IS_NOATIME(&ip->i_inode)) {
		struct gfs2_holder i_gh;
		int error;

		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (error)
			return error;
		/* grab lock to update inode */
		gfs2_glock_dq_uninit(&i_gh);
		file_accessed(file);
	}
	vma->vm_ops = &gfs2_vm_ops;

	return 0;
}

/**
 * gfs2_open_common - This is common to open and atomic_open
 * @inode: The inode being opened
 * @file: The file being opened
 *
 * This maybe called under a glock or not depending upon how it has
 * been called. We must always be called under a glock for regular
 * files, however. For other file types, it does not matter whether
 * we hold the glock or not.
 *
 * Returns: Error code or 0 for success
 */

int gfs2_open_common(struct inode *inode, struct file *file)
{
	struct gfs2_file *fp;
	int ret;

	if (S_ISREG(inode->i_mode)) {
		ret = generic_file_open(inode, file);
		if (ret)
			return ret;
	}

	fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS);
	if (!fp)
		return -ENOMEM;

	mutex_init(&fp->f_fl_mutex);

	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
	file->private_data = fp;
	return 0;
}

/**
 * gfs2_open - open a file
 * @inode: the inode to open
 * @file: the struct file for this opening
 *
 * After atomic_open, this function is only used for opening files
 * which are already cached. We must still get the glock for regular
 * files to ensure that we have the file size uptodate for the large
 * file check which is in the common code. That is only an issue for
 * regular files though.
 *
 * Returns: errno
 */

static int gfs2_open(struct inode *inode, struct file *file)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder i_gh;
	int error;
	bool need_unlock = false;

	if (S_ISREG(ip->i_inode.i_mode)) {
		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (error)
			return error;
		need_unlock = true;
	}

	error = gfs2_open_common(inode, file);

	if (need_unlock)
		gfs2_glock_dq_uninit(&i_gh);

	return error;
}

/**
 * gfs2_release - called to close a struct file
 * @inode: the inode the struct file belongs to
 * @file: the struct file being closed
 *
 * Returns: errno
 */

static int gfs2_release(struct inode *inode, struct file *file)
{
	struct gfs2_inode *ip = GFS2_I(inode);

	kfree(file->private_data);
	file->private_data = NULL;

	if (!(file->f_mode & FMODE_WRITE))
		return 0;

	gfs2_rs_delete(ip, &inode->i_writecount);
	return 0;
}

/**
 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 * @file: the file that points to the dentry
 * @start: the start position in the file to sync
 * @end: the end position in the file to sync
 * @datasync: set if we can ignore timestamp changes
 *
 * We split the data flushing here so that we don't wait for the data
 * until after we've also sent the metadata to disk. Note that for
 * data=ordered, we will write & wait for the data at the log flush
 * stage anyway, so this is unlikely to make much of a difference
 * except in the data=writeback case.
 *
 * If the fdatawrite fails due to any reason except -EIO, we will
 * continue the remainder of the fsync, although we'll still report
 * the error at the end. This is to match filemap_write_and_wait_range()
 * behaviour.
 *
 * Returns: errno
 */

static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
		      int datasync)
{
	struct address_space *mapping = file->f_mapping;
	struct inode *inode = mapping->host;
	int sync_state = inode->i_state & I_DIRTY_ALL;
	struct gfs2_inode *ip = GFS2_I(inode);
	int ret = 0, ret1 = 0;

	if (mapping->nrpages) {
		ret1 = filemap_fdatawrite_range(mapping, start, end);
		if (ret1 == -EIO)
			return ret1;
	}

	if (!gfs2_is_jdata(ip))
		sync_state &= ~I_DIRTY_PAGES;
	if (datasync)
		sync_state &= ~(I_DIRTY_SYNC | I_DIRTY_TIME);

	if (sync_state) {
		ret = sync_inode_metadata(inode, 1);
		if (ret)
			return ret;
		if (gfs2_is_jdata(ip))
			filemap_write_and_wait(mapping);
		gfs2_ail_flush(ip->i_gl, 1);
	}

	if (mapping->nrpages)
		ret = filemap_fdatawait_range(mapping, start, end);

	return ret ? ret : ret1;
}

/**
 * gfs2_file_write_iter - Perform a write to a file
 * @iocb: The io context
 * @iov: The data to write
 * @nr_segs: Number of @iov segments
 * @pos: The file position
 *
 * We have to do a lock/unlock here to refresh the inode size for
 * O_APPEND writes, otherwise we can land up writing at the wrong
 * offset. There is still a race, but provided the app is using its
 * own file locking, this will make O_APPEND work as expected.
 *
 */

static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
	struct file *file = iocb->ki_filp;
	struct gfs2_inode *ip = GFS2_I(file_inode(file));
	int ret;

	ret = gfs2_rs_alloc(ip);
	if (ret)
		return ret;

	gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from));

	if (iocb->ki_flags & IOCB_APPEND) {
		struct gfs2_holder gh;

		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
		if (ret)
			return ret;
		gfs2_glock_dq_uninit(&gh);
	}

	return generic_file_write_iter(iocb, from);
}

static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
			   int mode)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct buffer_head *dibh;
	int error;
	unsigned int nr_blks;
	sector_t lblock = offset >> inode->i_blkbits;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (unlikely(error))
		return error;

	gfs2_trans_add_meta(ip->i_gl, dibh);

	if (gfs2_is_stuffed(ip)) {
		error = gfs2_unstuff_dinode(ip, NULL);
		if (unlikely(error))
			goto out;
	}

	while (len) {
		struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
		bh_map.b_size = len;
		set_buffer_zeronew(&bh_map);

		error = gfs2_block_map(inode, lblock, &bh_map, 1);
		if (unlikely(error))
			goto out;
		len -= bh_map.b_size;
		nr_blks = bh_map.b_size >> inode->i_blkbits;
		lblock += nr_blks;
		if (!buffer_new(&bh_map))
			continue;
		if (unlikely(!buffer_zeronew(&bh_map))) {
			error = -EIO;
			goto out;
		}
	}
out:
	brelse(dibh);
	return error;
}
/**
 * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of
 *                     blocks, determine how many bytes can be written.
 * @ip:          The inode in question.
 * @len:         Max cap of bytes. What we return in *len must be <= this.
 * @data_blocks: Compute and return the number of data blocks needed
 * @ind_blocks:  Compute and return the number of indirect blocks needed
 * @max_blocks:  The total blocks available to work with.
 *
 * Returns: void, but @len, @data_blocks and @ind_blocks are filled in.
 */
static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len,
			    unsigned int *data_blocks, unsigned int *ind_blocks,
			    unsigned int max_blocks)
{
	loff_t max = *len;
	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);

	for (tmp = max_data; tmp > sdp->sd_diptrs;) {
		tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
		max_data -= tmp;
	}

	*data_blocks = max_data;
	*ind_blocks = max_blocks - max_data;
	*len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
	if (*len > max) {
		*len = max;
		gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
	}
}

static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
{
	struct inode *inode = file_inode(file);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_alloc_parms ap = { .aflags = 0, };
	unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
	loff_t bytes, max_bytes, max_blks = UINT_MAX;
	int error;
	const loff_t pos = offset;
	const loff_t count = len;
	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
	loff_t max_chunk_size = UINT_MAX & bsize_mask;

	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;

	offset &= bsize_mask;

	len = next - offset;
	bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
	if (!bytes)
		bytes = UINT_MAX;
	bytes &= bsize_mask;
	if (bytes == 0)
		bytes = sdp->sd_sb.sb_bsize;

	gfs2_size_hint(file, offset, len);

	gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
	ap.min_target = data_blocks + ind_blocks;

	while (len > 0) {
		if (len < bytes)
			bytes = len;
		if (!gfs2_write_alloc_required(ip, offset, bytes)) {
			len -= bytes;
			offset += bytes;
			continue;
		}

		/* We need to determine how many bytes we can actually
		 * fallocate without exceeding quota or going over the
		 * end of the fs. We start off optimistically by assuming
		 * we can write max_bytes */
		max_bytes = (len > max_chunk_size) ? max_chunk_size : len;

		/* Since max_bytes is most likely a theoretical max, we
		 * calculate a more realistic 'bytes' to serve as a good
		 * starting point for the number of bytes we may be able
		 * to write */
		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
		ap.target = data_blocks + ind_blocks;

		error = gfs2_quota_lock_check(ip, &ap);
		if (error)
			return error;
		/* ap.allowed tells us how many blocks quota will allow
		 * us to write. Check if this reduces max_blks */
		if (ap.allowed && ap.allowed < max_blks)
			max_blks = ap.allowed;

		error = gfs2_inplace_reserve(ip, &ap);
		if (error)
			goto out_qunlock;

		/* check if the selected rgrp limits our max_blks further */
		if (ap.allowed && ap.allowed < max_blks)
			max_blks = ap.allowed;

		/* Almost done. Calculate bytes that can be written using
		 * max_blks. We also recompute max_bytes, data_blocks and
		 * ind_blocks */
		calc_max_reserv(ip, &max_bytes, &data_blocks,
				&ind_blocks, max_blks);

		rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
			  RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks);
		if (gfs2_is_jdata(ip))
			rblocks += data_blocks ? data_blocks : 1;

		error = gfs2_trans_begin(sdp, rblocks,
					 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
		if (error)
			goto out_trans_fail;

		error = fallocate_chunk(inode, offset, max_bytes, mode);
		gfs2_trans_end(sdp);

		if (error)
			goto out_trans_fail;

		len -= max_bytes;
		offset += max_bytes;
		gfs2_inplace_release(ip);
		gfs2_quota_unlock(ip);
	}

	if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size) {
		i_size_write(inode, pos + count);
		file_update_time(file);
		mark_inode_dirty(inode);
	}

	return generic_write_sync(file, pos, count);

out_trans_fail:
	gfs2_inplace_release(ip);
out_qunlock:
	gfs2_quota_unlock(ip);
	return error;
}

static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
{
	struct inode *inode = file_inode(file);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	int ret;

	if ((mode & ~FALLOC_FL_KEEP_SIZE) || gfs2_is_jdata(ip))
		return -EOPNOTSUPP;

	mutex_lock(&inode->i_mutex);

	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	ret = gfs2_glock_nq(&gh);
	if (ret)
		goto out_uninit;

	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
	    (offset + len) > inode->i_size) {
		ret = inode_newsize_ok(inode, offset + len);
		if (ret)
			goto out_unlock;
	}

	ret = get_write_access(inode);
	if (ret)
		goto out_unlock;

	ret = gfs2_rs_alloc(ip);
	if (ret)
		goto out_putw;

	ret = __gfs2_fallocate(file, mode, offset, len);
	if (ret)
		gfs2_rs_deltree(ip->i_res);
out_putw:
	put_write_access(inode);
out_unlock:
	gfs2_glock_dq(&gh);
out_uninit:
	gfs2_holder_uninit(&gh);
	mutex_unlock(&inode->i_mutex);
	return ret;
}

static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe,
				      struct file *out, loff_t *ppos,
				      size_t len, unsigned int flags)
{
	int error;
	struct gfs2_inode *ip = GFS2_I(out->f_mapping->host);

	error = gfs2_rs_alloc(ip);
	if (error)
		return (ssize_t)error;

	gfs2_size_hint(out, *ppos, len);

	return iter_file_splice_write(pipe, out, ppos, len, flags);
}

#ifdef CONFIG_GFS2_FS_LOCKING_DLM

/**
 * gfs2_lock - acquire/release a posix lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;

	if (!(fl->fl_flags & FL_POSIX))
		return -ENOLCK;
	if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
		return -ENOLCK;

	if (cmd == F_CANCELLK) {
		/* Hack: */
		cmd = F_SETLK;
		fl->fl_type = F_UNLCK;
	}
	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
		if (fl->fl_type == F_UNLCK)
			locks_lock_file_wait(file, fl);
		return -EIO;
	}
	if (IS_GETLK(cmd))
		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
	else if (fl->fl_type == F_UNLCK)
		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
	else
		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
}

static int do_flock(struct file *file, int cmd, struct file_lock *fl)
{
	struct gfs2_file *fp = file->private_data;
	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
	struct gfs2_inode *ip = GFS2_I(file_inode(file));
	struct gfs2_glock *gl;
	unsigned int state;
	int flags;
	int error = 0;
	int sleeptime;

	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY_1CB) | GL_EXACT;

	mutex_lock(&fp->f_fl_mutex);

	gl = fl_gh->gh_gl;
	if (gl) {
		if (fl_gh->gh_state == state)
			goto out;
		locks_lock_file_wait(file,
				     &(struct file_lock){.fl_type = F_UNLCK});
		gfs2_glock_dq(fl_gh);
		gfs2_holder_reinit(state, flags, fl_gh);
	} else {
Example #5
0
static int hpfs_unlink(struct inode *dir, struct dentry *dentry)
{
	const unsigned char *name = dentry->d_name.name;
	unsigned len = dentry->d_name.len;
	struct quad_buffer_head qbh;
	struct hpfs_dirent *de;
	struct inode *inode = dentry->d_inode;
	dnode_secno dno;
	fnode_secno fno;
	int r;
	int rep = 0;
	int err;

	lock_kernel();
	hpfs_adjust_length(name, &len);
again:
	mutex_lock(&hpfs_i(inode)->i_parent_mutex);
	mutex_lock(&hpfs_i(dir)->i_mutex);
	err = -ENOENT;
	de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, &dno, &qbh);
	if (!de)
		goto out;

	err = -EPERM;
	if (de->first)
		goto out1;

	err = -EISDIR;
	if (de->directory)
		goto out1;

	fno = de->fnode;
	r = hpfs_remove_dirent(dir, dno, de, &qbh, 1);
	switch (r) {
	case 1:
		hpfs_error(dir->i_sb, "there was error when removing dirent");
		err = -EFSERROR;
		break;
	case 2:		/* no space for deleting, try to truncate file */

		err = -ENOSPC;
		if (rep++)
			break;

		mutex_unlock(&hpfs_i(dir)->i_mutex);
		mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
		dentry_unhash(dentry);
		if (!d_unhashed(dentry)) {
			dput(dentry);
			unlock_kernel();
			return -ENOSPC;
		}
		if (generic_permission(inode, MAY_WRITE, 0, NULL) ||
		    !S_ISREG(inode->i_mode) ||
		    get_write_access(inode)) {
			d_rehash(dentry);
			dput(dentry);
		} else {
			struct iattr newattrs;
			/*printk("HPFS: truncating file before delete.\n");*/
			newattrs.ia_size = 0;
			newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
			err = notify_change(dentry, &newattrs);
			put_write_access(inode);
			dput(dentry);
			if (!err)
				goto again;
		}
		unlock_kernel();
		return -ENOSPC;
	default:
		drop_nlink(inode);
		err = 0;
	}
	goto out;

out1:
	hpfs_brelse4(&qbh);
out:
	mutex_unlock(&hpfs_i(dir)->i_mutex);
	mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
	unlock_kernel();
	return err;
}
Example #6
0
static int do_dentry_open(struct file *f,
			  struct inode *inode,
			  int (*open)(struct inode *, struct file *),
			  const struct cred *cred)
{
	static const struct file_operations empty_fops = {};
	int error;

	f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
				FMODE_PREAD | FMODE_PWRITE;

	path_get(&f->f_path);
	f->f_inode = inode;
	f->f_mapping = inode->i_mapping;

	if (unlikely(f->f_flags & O_PATH)) {
		f->f_mode = FMODE_PATH;
		f->f_op = &empty_fops;
		return 0;
	}

	if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
		error = get_write_access(inode);
		if (unlikely(error))
			goto cleanup_file;
		error = __mnt_want_write(f->f_path.mnt);
		if (unlikely(error)) {
			put_write_access(inode);
			goto cleanup_file;
		}
		f->f_mode |= FMODE_WRITER;
	}

	/* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */
	if (S_ISREG(inode->i_mode))
		f->f_mode |= FMODE_ATOMIC_POS;

	f->f_op = fops_get(inode->i_fop);
	if (unlikely(WARN_ON(!f->f_op))) {
		error = -ENODEV;
		goto cleanup_all;
	}

	error = security_file_open(f, cred);
	if (error)
		goto cleanup_all;

	error = break_lease(inode, f->f_flags);
	if (error)
		goto cleanup_all;

	if (!open)
		open = f->f_op->open;
	if (open) {
		error = open(inode, f);
		if (error)
			goto cleanup_all;
	}
	if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
		i_readcount_inc(inode);
	if ((f->f_mode & FMODE_READ) &&
	     likely(f->f_op->read || f->f_op->read_iter))
		f->f_mode |= FMODE_CAN_READ;
	if ((f->f_mode & FMODE_WRITE) &&
	     likely(f->f_op->write || f->f_op->write_iter))
		f->f_mode |= FMODE_CAN_WRITE;

	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);

	return 0;

cleanup_all:
	fops_put(f->f_op);
	if (f->f_mode & FMODE_WRITER) {
		put_write_access(inode);
		__mnt_drop_write(f->f_path.mnt);
	}
cleanup_file:
	path_put(&f->f_path);
	f->f_path.mnt = NULL;
	f->f_path.dentry = NULL;
	f->f_inode = NULL;
	return error;
}
Example #7
0
static inline int
do_aout_core_dump(long signr, struct pt_regs * regs)
{
	struct inode * inode = NULL;
	struct file file;
	unsigned short fs;
	int has_dumped = 0;
	char corefile[6+sizeof(current->comm)];
	unsigned long dump_start, dump_size;
	struct user dump;
#ifdef __alpha__
#       define START_DATA(u)	(u.start_data)
#elif defined(CONFIG_ARM)
#	define START_DATA(u)	((u.u_tsize << PAGE_SHIFT) + u.start_code)
#else
#       define START_DATA(u)	(u.u_tsize << PAGE_SHIFT)
#endif

	if (!current->dumpable || current->mm->count != 1)
		return 0;
	current->dumpable = 0;

/* See if we have enough room to write the upage.  */
	if (current->rlim[RLIMIT_CORE].rlim_cur < PAGE_SIZE)
		return 0;
	fs = get_fs();
	set_fs(KERNEL_DS);
	memcpy(corefile,"core.",5);
#if 0
	memcpy(corefile+5,current->comm,sizeof(current->comm));
#else
	corefile[4] = '\0';
#endif
	if (open_namei(corefile,O_CREAT | 2 | O_TRUNC,0600,&inode,NULL)) {
		inode = NULL;
		goto end_coredump;
	}
	if (!S_ISREG(inode->i_mode))
		goto end_coredump;
	if (!inode->i_op || !inode->i_op->default_file_ops)
		goto end_coredump;
	if (get_write_access(inode))
		goto end_coredump;
	file.f_mode = 3;
	file.f_flags = 0;
	file.f_count = 1;
	file.f_inode = inode;
	file.f_pos = 0;
	file.f_reada = 0;
	file.f_op = inode->i_op->default_file_ops;
	if (file.f_op->open)
		if (file.f_op->open(inode,&file))
			goto done_coredump;
	if (!file.f_op->write)
		goto close_coredump;
	has_dumped = 1;
	current->flags |= PF_DUMPCORE;
       	strncpy(dump.u_comm, current->comm, sizeof(current->comm));
	dump.u_ar0 = (void *)(((unsigned long)(&dump.regs)) - ((unsigned long)(&dump)));
	dump.signal = signr;
	dump_thread(regs, &dump);

/* If the size of the dump file exceeds the rlimit, then see what would happen
   if we wrote the stack, but not the data area.  */
	if ((dump.u_dsize+dump.u_ssize+1) * PAGE_SIZE >
	    current->rlim[RLIMIT_CORE].rlim_cur)
		dump.u_dsize = 0;

/* Make sure we have enough room to write the stack and data areas. */
	if ((dump.u_ssize+1) * PAGE_SIZE >
	    current->rlim[RLIMIT_CORE].rlim_cur)
		dump.u_ssize = 0;

/* make sure we actually have a data and stack area to dump */
	set_fs(USER_DS);
	if (verify_area(VERIFY_READ, (void *) START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
		dump.u_dsize = 0;
	if (verify_area(VERIFY_READ, (void *) dump.start_stack, dump.u_ssize << PAGE_SHIFT))
		dump.u_ssize = 0;

	set_fs(KERNEL_DS);
/* struct user */
	DUMP_WRITE(&dump,sizeof(dump));
/* Now dump all of the user data.  Include malloced stuff as well */
	DUMP_SEEK(PAGE_SIZE);
/* now we start writing out the user space info */
	set_fs(USER_DS);
/* Dump the data area */
	if (dump.u_dsize != 0) {
		dump_start = START_DATA(dump);
		dump_size = dump.u_dsize << PAGE_SHIFT;
		DUMP_WRITE(dump_start,dump_size);
	}
/* Now prepare to dump the stack area */
	if (dump.u_ssize != 0) {
		dump_start = dump.start_stack;
		dump_size = dump.u_ssize << PAGE_SHIFT;
		DUMP_WRITE(dump_start,dump_size);
	}
/* Finally dump the task struct.  Not be used by gdb, but could be useful */
	set_fs(KERNEL_DS);
	DUMP_WRITE(current,sizeof(*current));
close_coredump:
	if (file.f_op->release)
		file.f_op->release(inode,&file);
done_coredump:
	put_write_access(inode);
end_coredump:
	set_fs(fs);
	iput(inode);
	return has_dumped;
}
Example #8
0
File: open.c Project: 274914765/C
static long do_sys_truncate(const char __user * path, loff_t length)
{
    struct nameidata nd;
    struct inode * inode;
    int error;

    error = -EINVAL;
    if (length < 0)    /* sorry, but loff_t says... */
        goto out;

    error = user_path_walk(path, &nd);
    if (error)
        goto out;
    inode = nd.path.dentry->d_inode;

    /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
    error = -EISDIR;
    if (S_ISDIR(inode->i_mode))
        goto dput_and_out;

    error = -EINVAL;
    if (!S_ISREG(inode->i_mode))
        goto dput_and_out;

    error = mnt_want_write(nd.path.mnt);
    if (error)
        goto dput_and_out;

    error = vfs_permission(&nd, MAY_WRITE);
    if (error)
        goto mnt_drop_write_and_out;

    error = -EPERM;
    if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
        goto mnt_drop_write_and_out;

    error = get_write_access(inode);
    if (error)
        goto mnt_drop_write_and_out;

    /*
     * Make sure that there are no leases.  get_write_access() protects
     * against the truncate racing with a lease-granting setlease().
     */
    error = break_lease(inode, FMODE_WRITE);
    if (error)
        goto put_write_and_out;

    error = locks_verify_truncate(inode, NULL, length);
    if (!error) {
        DQUOT_INIT(inode);
        error = do_truncate(nd.path.dentry, length, 0, NULL);
    }

put_write_and_out:
    put_write_access(inode);
mnt_drop_write_and_out:
    mnt_drop_write(nd.path.mnt);
dput_and_out:
    path_put(&nd.path);
out:
    return error;
}
Example #9
0
File: open.c Project: 274914765/C
static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
                    int flags, struct file *f,
                    int (*open)(struct inode *, struct file *))
{
    struct inode *inode;
    int error;

    f->f_flags = flags;
    f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
                FMODE_PREAD | FMODE_PWRITE;
    inode = dentry->d_inode;
    if (f->f_mode & FMODE_WRITE) {
        error = __get_file_write_access(inode, mnt);
        if (error)
            goto cleanup_file;
        if (!special_file(inode->i_mode))
            file_take_write(f);
    }

    f->f_mapping = inode->i_mapping;
    f->f_path.dentry = dentry;
    f->f_path.mnt = mnt;
    f->f_pos = 0;
    f->f_op = fops_get(inode->i_fop);
    file_move(f, &inode->i_sb->s_files);

    error = security_dentry_open(f);
    if (error)
        goto cleanup_all;

    if (!open && f->f_op)
        open = f->f_op->open;
    if (open) {
        error = open(inode, f);
        if (error)
            goto cleanup_all;
    }

    f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

    file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);

    /* NB: we're sure to have correct a_ops only after f_op->open */
    if (f->f_flags & O_DIRECT) {
        if (!f->f_mapping->a_ops ||
            ((!f->f_mapping->a_ops->direct_IO) &&
            (!f->f_mapping->a_ops->get_xip_mem))) {
            fput(f);
            f = ERR_PTR(-EINVAL);
        }
    }

    return f;

cleanup_all:
    fops_put(f->f_op);
    if (f->f_mode & FMODE_WRITE) {
        put_write_access(inode);
        if (!special_file(inode->i_mode)) {
            /*
             * We don't consider this a real
             * mnt_want/drop_write() pair
             * because it all happenend right
             * here, so just reset the state.
             */
            file_reset_write(f);
            mnt_drop_write(mnt);
        }
    }
    file_kill(f);
    f->f_path.dentry = NULL;
    f->f_path.mnt = NULL;
cleanup_file:
    put_filp(f);
    dput(dentry);
    mntput(mnt);
    return ERR_PTR(error);
}
Example #10
0
int sys_open(char *filename, int flags, int mode)
{
    struct inode *inode;
    register struct file *f;
    int error, fd, flag;

    f = get_empty_filp();
    if (!f) {
	printk("\nNo filps\n");
	return -ENFILE;
    }
    f->f_flags = (unsigned short int) (flag = flags);
    f->f_mode = (mode_t) ((flag + 1) & O_ACCMODE);
    if (f->f_mode)
	flag++;
    if (flag & (O_TRUNC | O_CREAT))
	flag |= 2;
    error = open_namei(filename, flag, mode, &inode, NULL);

    if (!error) {

#ifdef BLOAT_FS
	if (f->f_mode & FMODE_WRITE) {
	    error = get_write_access(inode);
	    if (error)
		goto cleanup_inode;
	}
#endif

	f->f_inode = inode;
	f->f_pos = 0;

#ifdef BLOAT_FS
	f->f_reada = 0;
#endif

	f->f_op = NULL;
	{
	    register struct inode_operations *iop = inode->i_op;
	    if (iop)
		f->f_op = iop->default_file_ops;
	}
	{
	    register struct file_operations *fop = f->f_op;
	    if (fop && fop->open) {
		error = fop->open(inode, f);
		if (error) {
		    goto cleanup_all;
		}
	    }
	    f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	    /*
	     * We have to do this last, because we mustn't export
	     * an incomplete fd to other processes which may share
	     * the same file table with us.
	     */
	    if ((fd = get_unused_fd()) > -1) {
		current->files.fd[fd] = f;
		return fd;
	    }
	    error = -EMFILE;
	    if (fop && fop->release)
		fop->release(inode, f);
	}
      cleanup_all:
#ifdef BLOAT_FS
	if (f->f_mode & FMODE_WRITE)
	    put_write_access(inode);
      cleanup_inode:
#endif
	iput(inode);
    }
  cleanup_file:
    f->f_count--;
    return error;
}
Example #11
0
/*
 * Don't grab the superblock read-lock in unionfs_permission, which prevents
 * a deadlock with the branch-management "add branch" code (which grabbed
 * the write lock).  It is safe to not grab the read lock here, because even
 * with branch management taking place, there is no chance that
 * unionfs_permission, or anything it calls, will use stale branch
 * information.
 */
static int unionfs_permission(struct inode *inode, int mask)
{
	struct inode *lower_inode = NULL;
	int err = 0;
	int bindex, bstart, bend;
	const int is_file = !S_ISDIR(inode->i_mode);
	const int write_mask = (mask & MAY_WRITE) && !(mask & MAY_READ);
	struct inode *inode_grabbed = igrab(inode);
	struct dentry *dentry = d_find_alias(inode);

	if (dentry)
		unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);

	if (!UNIONFS_I(inode)->lower_inodes) {
		if (is_file)	/* dirs can be unlinked but chdir'ed to */
			err = -ESTALE;	/* force revalidate */
		goto out;
	}
	bstart = ibstart(inode);
	bend = ibend(inode);
	if (unlikely(bstart < 0 || bend < 0)) {
		/*
		 * With branch-management, we can get a stale inode here.
		 * If so, we return ESTALE back to link_path_walk, which
		 * would discard the dcache entry and re-lookup the
		 * dentry+inode.  This should be equivalent to issuing
		 * __unionfs_d_revalidate_chain on nd.dentry here.
		 */
		if (is_file)	/* dirs can be unlinked but chdir'ed to */
			err = -ESTALE;	/* force revalidate */
		goto out;
	}

	for (bindex = bstart; bindex <= bend; bindex++) {
		lower_inode = unionfs_lower_inode_idx(inode, bindex);
		if (!lower_inode)
			continue;

		/*
		 * check the condition for D-F-D underlying files/directories,
		 * we don't have to check for files, if we are checking for
		 * directories.
		 */
		if (!is_file && !S_ISDIR(lower_inode->i_mode))
			continue;

		/*
		 * We check basic permissions, but we ignore any conditions
		 * such as readonly file systems or branches marked as
		 * readonly, because those conditions should lead to a
		 * copyup taking place later on.  However, if user never had
		 * access to the file, then no copyup could ever take place.
		 */
		err = __inode_permission(lower_inode, mask);
		if (err && err != -EACCES && err != EPERM && bindex > 0) {
			umode_t mode = lower_inode->i_mode;
			if ((is_robranch_super(inode->i_sb, bindex) ||
			     __is_rdonly(lower_inode)) &&
			    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
				err = 0;
			if (IS_COPYUP_ERR(err))
				err = 0;
		}

		/*
		 * NFS HACK: NFSv2/3 return EACCES on readonly-exported,
		 * locally readonly-mounted file systems, instead of EROFS
		 * like other file systems do.  So we have no choice here
		 * but to intercept this and ignore it for NFS branches
		 * marked readonly.  Specifically, we avoid using NFS's own
		 * "broken" ->permission method, and rely on
		 * generic_permission() to do basic checking for us.
		 */
		if (err && err == -EACCES &&
		    is_robranch_super(inode->i_sb, bindex) &&
		    lower_inode->i_sb->s_magic == NFS_SUPER_MAGIC)
			err = generic_permission(lower_inode, mask, NULL);

		/*
		 * The permissions are an intersection of the overall directory
		 * permissions, so we fail if one fails.
		 */
		if (err)
			goto out;

		/* only the leftmost file matters. */
		if (is_file || write_mask) {
			if (is_file && write_mask) {
				err = get_write_access(lower_inode);
				if (!err)
					put_write_access(lower_inode);
			}
			break;
		}
	}
	/* sync times which may have changed (asynchronously) below */
	unionfs_copy_attr_times(inode);

out:
	unionfs_check_inode(inode);
	if (dentry) {
		unionfs_unlock_dentry(dentry);
		dput(dentry);
	}
	iput(inode_grabbed);
	return err;
}
static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
					int flags, struct file *f,
					int (*open)(struct inode *, struct file *))
{
	struct inode *inode;
	int error;

	f->f_flags = flags;
	f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
				FMODE_PREAD | FMODE_PWRITE;
	inode = dentry->d_inode;
	if (f->f_mode & FMODE_WRITE) {
		error = get_write_access(inode);
		if (error)
			goto cleanup_file;
	}

	f->f_mapping = inode->i_mapping;
	f->f_dentry = dentry;
	f->f_vfsmnt = mnt;
	f->f_pos = 0;
	f->f_op = fops_get(inode->i_fop);
	file_move(f, &inode->i_sb->s_files);

	if (!open && f->f_op)
		open = f->f_op->open;
	if (open) {
		error = open(inode, f);
		if (error)
			goto cleanup_all;
	}

	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);

	/* NB: we're sure to have correct a_ops only after f_op->open */
	if (f->f_flags & O_DIRECT) {
		if (!f->f_mapping->a_ops ||
		    ((!f->f_mapping->a_ops->direct_IO) &&
		    (!f->f_mapping->a_ops->get_xip_page))) {
			fput(f);
			f = ERR_PTR(-EINVAL);
		}
	}

	return f;

cleanup_all:
	fops_put(f->f_op);
	if (f->f_mode & FMODE_WRITE)
		put_write_access(inode);
	file_kill(f);
	f->f_dentry = NULL;
	f->f_vfsmnt = NULL;
cleanup_file:
	put_filp(f);
	dput(dentry);
	mntput(mnt);
	return ERR_PTR(error);
}
Example #13
0
static int do_dentry_open(struct file *f,
			  int (*open)(struct inode *, struct file *),
			  const struct cred *cred)
{
	static const struct file_operations empty_fops = {};
	struct inode *inode;
	int error;

	f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
				FMODE_PREAD | FMODE_PWRITE;

	if (unlikely(f->f_flags & O_PATH))
		f->f_mode = FMODE_PATH;

	path_get(&f->f_path);
	inode = f->f_inode = f->f_path.dentry->d_inode;
	if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
		error = __get_file_write_access(inode, f->f_path.mnt);
		if (error)
			goto cleanup_file;
		file_take_write(f);
	}

	f->f_mapping = inode->i_mapping;
	file_sb_list_add(f, inode->i_sb);

	if (unlikely(f->f_mode & FMODE_PATH)) {
		f->f_op = &empty_fops;
		return 0;
	}

	f->f_op = fops_get(inode->i_fop);

	error = security_file_open(f, cred);
	if (error)
		goto cleanup_all;

	error = break_lease(inode, f->f_flags);
	if (error)
		goto cleanup_all;

	if (!open && f->f_op)
		open = f->f_op->open;
	if (open) {
		error = open(inode, f);
		if (error)
			goto cleanup_all;
	}
	if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
		i_readcount_inc(inode);

	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);

	return 0;

cleanup_all:
	fops_put(f->f_op);
	file_sb_list_del(f);
	if (f->f_mode & FMODE_WRITE) {
		if (!special_file(inode->i_mode)) {
			/*
			 * We don't consider this a real
			 * mnt_want/drop_write() pair
			 * because it all happenend right
			 * here, so just reset the state.
			 */
			put_write_access(inode);
			file_reset_write(f);
			__mnt_drop_write(f->f_path.mnt);
		}
	}
cleanup_file:
	path_put(&f->f_path);
	f->f_path.mnt = NULL;
	f->f_path.dentry = NULL;
	f->f_inode = NULL;
	return error;
}
Example #14
0
extern int
vnode_shadow_fop_open(
    INODE_T *inode,
    FILE_T *file
)
{
    int err = 0;
    INODE_T *real_inode;
    DENT_T *rdentry = NULL;
    DENT_T *oldent;
    struct file_operations *oldfops;
    struct vfsmount *oldmnt, *newmnt;
    VNODE_T *cvp;

    oldmnt = file->f_vfsmnt;

    oldent = file->f_dentry;
    ASSERT(D_COUNT(oldent));
    /* The Linux kernel has stopped ignoring the O_DIRECT flag.
     * The problem is that they wait until after they call the fop open
     * function to check the inode to see if it will support direct I/O.
     * But they get the inode pointer before they call us and check the
     * inode after we return so they never check the actual inode we open
     * but only the shadow one.  Their error handling never comes back to
     * us and they release their old pointers and not our new ones.  The
     * only choice we have is to not allow O_DIRECT on shadow files.
     */
    if (file->f_flags & O_DIRECT) {
        err = -EINVAL;
        goto out_nolock;
    }
    /* Get the real dentry */
    rdentry = REALDENTRY_LOCKED(oldent, &cvp);
    if (rdentry == NULL) {
        err = -ENOENT;
	goto out_nolock;
    }
    VNODE_DGET(rdentry);                 /* protect rdentry->d_inode */
    if (rdentry->d_inode == NULL) {
        /* delete race */
        err = -ENOENT;
        goto out;
    }
    newmnt = MDKI_MNTGET(REALVFSMNT(oldent));
    if (newmnt == NULL) {
        err = -EOPNOTSUPP;             /* XXX */
        goto out;
    }

    /* Check that we can write to this file.  Clean up the count on the
     * shadow inode.
     */
    if (file->f_mode & FMODE_WRITE) {
        err = get_write_access(rdentry->d_inode);
        if (err) {
            MDKI_MNTPUT(newmnt);
            goto out;
        }
    }
    real_inode = rdentry->d_inode;

    /* 
     * Swap the file structure contents to point at the underlying object.
     */
    /* In Linux 2.6 they added the mapping stuff to the file so we have to set
    ** that up here, too.
    */
    file->f_mapping = real_inode->i_mapping;
    VNLAYER_RA_STATE_INIT(&(file->f_ra), file->f_mapping);
    file->f_dentry = VNODE_DGET(rdentry);
    oldfops = file->f_op;
    file->f_vfsmnt = newmnt;
    file->f_op = fops_get(real_inode->i_fop);
    if (real_inode->i_fop && !file->f_op)
        /* If we failed to get the reference to a non-NULL op, bail out */
        err = -EIO;                     /* XXX? better error code */
    if (!err) {
	/* Move the file to the file list for the real superblock 
	 * and remove it from the shadow list
	 */
        /* It would be better to use file_move() but it's not exported */
	file_list_lock();
        list_del(&file->f_list);
        list_add(&file->f_list, &real_inode->i_sb->s_files);
	file_list_unlock();
	if (file->f_op && file->f_op->open) {
            err = (*file->f_op->open)(real_inode, file);
            if (err) {
	        /* restore our file to the list on our super block */
	        file_list_lock();
	        list_del(&file->f_list);
	        list_add(&file->f_list, &oldent->d_inode->i_sb->s_files);
	        file_list_unlock();
	    }
	}
    }
    if (err) {
        /* MUST put back old dentry/fops to get accounting right in upper
         * layer. */
        put_write_access(rdentry->d_inode);
        if (file->f_dentry)
            VNODE_DPUT(file->f_dentry);
        if (file->f_op)
            fops_put(file->f_op);
        MDKI_MNTPUT(file->f_vfsmnt);
        file->f_vfsmnt = oldmnt;
        file->f_dentry = oldent;
        file->f_op = oldfops;
    } else {
        put_write_access(oldent->d_inode);
        VNODE_DPUT(oldent);
        /* Drop reference now that we've dropped our use of the file ops */
        fops_put(oldfops);
        MDKI_MNTPUT(oldmnt);
    }
  out:
    VNODE_DPUT(rdentry);
    REALDENTRY_UNLOCK(oldent, cvp);
  out_nolock:
    MDKI_TRACE(TRACE_OPEN, "%s: opened vp=%p fp=%p rdent=%p rdcnt=%d fcnt=%d"
              ", err %d\n", __func__,
              inode, file, rdentry, rdentry ? D_COUNT(rdentry) : 0, F_COUNT(file), -err);
    return(err);
}