Пример #1
0
int
xfs_qm_vop_rename_dqattach(
	struct xfs_inode	**i_tab)
{
	struct xfs_mount	*mp = i_tab[0]->i_mount;
	int			i;

	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
		return 0;

	for (i = 0; (i < 4 && i_tab[i]); i++) {
		struct xfs_inode	*ip = i_tab[i];
		int			error;

		/*
		 * Watch out for duplicate entries in the table.
		 */
		if (i == 0 || ip != i_tab[i-1]) {
			if (XFS_NOT_DQATTACHED(mp, ip)) {
				error = xfs_qm_dqattach(ip, 0);
				if (error)
					return error;
			}
		}
	}
	return 0;
}
Пример #2
0
/*
 * Truncate file.  Must have write permission and not be a directory.
 */
int
xfs_setattr_size(
	struct xfs_inode	*ip,
	struct iattr		*iattr)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct inode		*inode = VFS_I(ip);
	xfs_off_t		oldsize, newsize;
	struct xfs_trans	*tp;
	int			error;
	uint			lock_flags = 0;
	uint			commit_flags = 0;

	trace_xfs_setattr(ip);

	if (mp->m_flags & XFS_MOUNT_RDONLY)
		return XFS_ERROR(EROFS);

	if (XFS_FORCED_SHUTDOWN(mp))
		return XFS_ERROR(EIO);

	error = -inode_change_ok(inode, iattr);
	if (error)
		return XFS_ERROR(error);

	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
	ASSERT(S_ISREG(ip->i_d.di_mode));
	ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
		ATTR_MTIME_SET|ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);

	oldsize = inode->i_size;
	newsize = iattr->ia_size;

	/*
	 * Short circuit the truncate case for zero length files.
	 */
	if (newsize == 0 && oldsize == 0 && ip->i_d.di_nextents == 0) {
		if (!(iattr->ia_valid & (ATTR_CTIME|ATTR_MTIME)))
			return 0;

		/*
		 * Use the regular setattr path to update the timestamps.
		 */
		iattr->ia_valid &= ~ATTR_SIZE;
		return xfs_setattr_nonsize(ip, iattr, 0);
	}

	/*
	 * Make sure that the dquots are attached to the inode.
	 */
	error = xfs_qm_dqattach(ip, 0);
	if (error)
		return error;

	/*
	 * Now we can make the changes.  Before we join the inode to the
	 * transaction, take care of the part of the truncation that must be
	 * done without the inode lock.  This needs to be done before joining
	 * the inode to the transaction, because the inode cannot be unlocked
	 * once it is a part of the transaction.
	 */
	if (newsize > oldsize) {
		/*
		 * Do the first part of growing a file: zero any data in the
		 * last block that is beyond the old EOF.  We need to do this
		 * before the inode is joined to the transaction to modify
		 * i_size.
		 */
		error = xfs_zero_eof(ip, newsize, oldsize);
		if (error)
			return error;
	}

	/*
	 * We are going to log the inode size change in this transaction so
	 * any previous writes that are beyond the on disk EOF and the new
	 * EOF that have not been written out need to be written here.  If we
	 * do not write the data out, we expose ourselves to the null files
	 * problem.
	 *
	 * Only flush from the on disk size to the smaller of the in memory
	 * file size or the new size as that's the range we really care about
	 * here and prevents waiting for other data not within the range we
	 * care about here.
	 */
	if (oldsize != ip->i_d.di_size && newsize > ip->i_d.di_size) {
		error = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
						      ip->i_d.di_size, newsize);
		if (error)
			return error;
	}

	/*
	 * Wait for all direct I/O to complete.
	 */
	inode_dio_wait(inode);

	error = -block_truncate_page(inode->i_mapping, newsize, xfs_get_blocks);
	if (error)
		return error;

	tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_SIZE);
	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
	if (error)
		goto out_trans_cancel;

	truncate_setsize(inode, newsize);

	commit_flags = XFS_TRANS_RELEASE_LOG_RES;
	lock_flags |= XFS_ILOCK_EXCL;

	xfs_ilock(ip, XFS_ILOCK_EXCL);

	xfs_trans_ijoin(tp, ip, 0);

	/*
	 * Only change the c/mtime if we are changing the size or we are
	 * explicitly asked to change it.  This handles the semantic difference
	 * between truncate() and ftruncate() as implemented in the VFS.
	 *
	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
	 * special case where we need to update the times despite not having
	 * these flags set.  For all other operations the VFS set these flags
	 * explicitly if it wants a timestamp update.
	 */
	if (newsize != oldsize &&
	    !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
		iattr->ia_ctime = iattr->ia_mtime =
			current_fs_time(inode->i_sb);
		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
	}

	/*
	 * The first thing we do is set the size to new_size permanently on
	 * disk.  This way we don't have to worry about anyone ever being able
	 * to look at the data being freed even in the face of a crash.
	 * What we're getting around here is the case where we free a block, it
	 * is allocated to another file, it is written to, and then we crash.
	 * If the new data gets written to the file but the log buffers
	 * containing the free and reallocation don't, then we'd end up with
	 * garbage in the blocks being freed.  As long as we make the new size
	 * permanent before actually freeing any blocks it doesn't matter if
	 * they get written to.
	 */
	ip->i_d.di_size = newsize;
	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

	if (newsize <= oldsize) {
		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
		if (error)
			goto out_trans_abort;

		/*
		 * Truncated "down", so we're removing references to old data
		 * here - if we delay flushing for a long time, we expose
		 * ourselves unduly to the notorious NULL files problem.  So,
		 * we mark this inode and flush it when the file is closed,
		 * and do not wait the usual (long) time for writeout.
		 */
		xfs_iflags_set(ip, XFS_ITRUNCATED);

		/* A truncate down always removes post-EOF blocks. */
		xfs_inode_clear_eofblocks_tag(ip);
	}

	if (iattr->ia_valid & ATTR_MODE)
		xfs_setattr_mode(ip, iattr);
	if (iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME))
		xfs_setattr_time(ip, iattr);

	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

	XFS_STATS_INC(xs_ig_attrchg);

	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(tp);

	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
out_unlock:
	if (lock_flags)
		xfs_iunlock(ip, lock_flags);
	return error;

out_trans_abort:
	commit_flags |= XFS_TRANS_ABORT;
out_trans_cancel:
	xfs_trans_cancel(tp, commit_flags);
	goto out_unlock;
}
Пример #3
0
int
xfs_alloc_file_space(
	struct xfs_inode	*ip,
	xfs_off_t		offset,
	xfs_off_t		len,
	int			alloc_type)
{
	xfs_mount_t		*mp = ip->i_mount;
	xfs_off_t		count;
	xfs_filblks_t		allocated_fsb;
	xfs_filblks_t		allocatesize_fsb;
	xfs_extlen_t		extsz, temp;
	xfs_fileoff_t		startoffset_fsb;
	xfs_fsblock_t		firstfsb;
	int			nimaps;
	int			quota_flag;
	int			rt;
	xfs_trans_t		*tp;
	xfs_bmbt_irec_t		imaps[1], *imapp;
	xfs_bmap_free_t		free_list;
	uint			qblocks, resblks, resrtextents;
	int			committed;
	int			error;

	trace_xfs_alloc_file_space(ip);

	if (XFS_FORCED_SHUTDOWN(mp))
		return XFS_ERROR(EIO);

	error = xfs_qm_dqattach(ip, 0);
	if (error)
		return error;

	if (len <= 0)
		return XFS_ERROR(EINVAL);

	rt = XFS_IS_REALTIME_INODE(ip);
	extsz = xfs_get_extsz_hint(ip);

	count = len;
	imapp = &imaps[0];
	nimaps = 1;
	startoffset_fsb	= XFS_B_TO_FSBT(mp, offset);
	allocatesize_fsb = XFS_B_TO_FSB(mp, count);

	/*
	 * Allocate file space until done or until there is an error
	 */
	while (allocatesize_fsb && !error) {
		xfs_fileoff_t	s, e;

		/*
		 * Determine space reservations for data/realtime.
		 */
		if (unlikely(extsz)) {
			s = startoffset_fsb;
			do_div(s, extsz);
			s *= extsz;
			e = startoffset_fsb + allocatesize_fsb;
			if ((temp = do_mod(startoffset_fsb, extsz)))
				e += temp;
			if ((temp = do_mod(e, extsz)))
				e += extsz - temp;
		} else {
			s = 0;
			e = allocatesize_fsb;
		}

		/*
		 * The transaction reservation is limited to a 32-bit block
		 * count, hence we need to limit the number of blocks we are
		 * trying to reserve to avoid an overflow. We can't allocate
		 * more than @nimaps extents, and an extent is limited on disk
		 * to MAXEXTLEN (21 bits), so use that to enforce the limit.
		 */
		resblks = min_t(xfs_fileoff_t, (e - s), (MAXEXTLEN * nimaps));
		if (unlikely(rt)) {
			resrtextents = qblocks = resblks;
			resrtextents /= mp->m_sb.sb_rextsize;
			resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
			quota_flag = XFS_QMOPT_RES_RTBLKS;
		} else {
			resrtextents = 0;
			resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
			quota_flag = XFS_QMOPT_RES_REGBLKS;
		}

		/*
		 * Allocate and setup the transaction.
		 */
		tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
					  resblks, resrtextents);
		/*
		 * Check for running out of space
		 */
		if (error) {
			/*
			 * Free the transaction structure.
			 */
			ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp));
			xfs_trans_cancel(tp, 0);
			break;
		}
		xfs_ilock(ip, XFS_ILOCK_EXCL);
		error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks,
						      0, quota_flag);
		if (error)
			goto error1;

		xfs_trans_ijoin(tp, ip, 0);

		xfs_bmap_init(&free_list, &firstfsb);
		error = xfs_bmapi_write(tp, ip, startoffset_fsb,
					allocatesize_fsb, alloc_type, &firstfsb,
					0, imapp, &nimaps, &free_list);
		if (error) {
			goto error0;
		}

		/*
		 * Complete the transaction
		 */
		error = xfs_bmap_finish(&tp, &free_list, &committed);
		if (error) {
			goto error0;
		}

		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
		xfs_iunlock(ip, XFS_ILOCK_EXCL);
		if (error) {
			break;
		}

		allocated_fsb = imapp->br_blockcount;

		if (nimaps == 0) {
			error = XFS_ERROR(ENOSPC);
			break;
		}

		startoffset_fsb += allocated_fsb;
		allocatesize_fsb -= allocated_fsb;
	}

	return error;

error0:	/* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
	xfs_bmap_cancel(&free_list);
	xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);

error1:	/* Just cancel transaction */
	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	return error;
}
Пример #4
0
/*
 * This is called by xfs_inactive to free any blocks beyond eof
 * when the link count isn't zero and by xfs_dm_punch_hole() when
 * punching a hole to EOF.
 */
int
xfs_free_eofblocks(
	xfs_mount_t	*mp,
	xfs_inode_t	*ip,
	bool		need_iolock)
{
	xfs_trans_t	*tp;
	int		error;
	xfs_fileoff_t	end_fsb;
	xfs_fileoff_t	last_fsb;
	xfs_filblks_t	map_len;
	int		nimaps;
	xfs_bmbt_irec_t	imap;

	/*
	 * Figure out if there are any blocks beyond the end
	 * of the file.  If not, then there is nothing to do.
	 */
	end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
	last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
	if (last_fsb <= end_fsb)
		return 0;
	map_len = last_fsb - end_fsb;

	nimaps = 1;
	xfs_ilock(ip, XFS_ILOCK_SHARED);
	error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0);
	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	if (!error && (nimaps != 0) &&
	    (imap.br_startblock != HOLESTARTBLOCK ||
	     ip->i_delayed_blks)) {
		/*
		 * Attach the dquots to the inode up front.
		 */
		error = xfs_qm_dqattach(ip, 0);
		if (error)
			return error;

		/*
		 * There are blocks after the end of file.
		 * Free them up now by truncating the file to
		 * its current size.
		 */
		tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);

		if (need_iolock) {
			if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
				xfs_trans_cancel(tp, 0);
				return EAGAIN;
			}
		}

		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
		if (error) {
			ASSERT(XFS_FORCED_SHUTDOWN(mp));
			xfs_trans_cancel(tp, 0);
			if (need_iolock)
				xfs_iunlock(ip, XFS_IOLOCK_EXCL);
			return error;
		}

		xfs_ilock(ip, XFS_ILOCK_EXCL);
		xfs_trans_ijoin(tp, ip, 0);

		/*
		 * Do not update the on-disk file size.  If we update the
		 * on-disk file size and then the system crashes before the
		 * contents of the file are flushed to disk then the files
		 * may be full of holes (ie NULL files bug).
		 */
		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK,
					      XFS_ISIZE(ip));
		if (error) {
			/*
			 * If we get an error at this point we simply don't
			 * bother truncating the file.
			 */
			xfs_trans_cancel(tp,
					 (XFS_TRANS_RELEASE_LOG_RES |
					  XFS_TRANS_ABORT));
		} else {
			error = xfs_trans_commit(tp,
						XFS_TRANS_RELEASE_LOG_RES);
			if (!error)
				xfs_inode_clear_eofblocks_tag(ip);
		}

		xfs_iunlock(ip, XFS_ILOCK_EXCL);
		if (need_iolock)
			xfs_iunlock(ip, XFS_IOLOCK_EXCL);
	}
	return error;
}
Пример #5
0
int
xfs_free_file_space(
	struct xfs_inode	*ip,
	xfs_off_t		offset,
	xfs_off_t		len)
{
	int			committed;
	int			done;
	xfs_fileoff_t		endoffset_fsb;
	int			error;
	xfs_fsblock_t		firstfsb;
	xfs_bmap_free_t		free_list;
	xfs_bmbt_irec_t		imap;
	xfs_off_t		ioffset;
	xfs_extlen_t		mod=0;
	xfs_mount_t		*mp;
	int			nimap;
	uint			resblks;
	xfs_off_t		rounding;
	int			rt;
	xfs_fileoff_t		startoffset_fsb;
	xfs_trans_t		*tp;

	mp = ip->i_mount;

	trace_xfs_free_file_space(ip);

	error = xfs_qm_dqattach(ip, 0);
	if (error)
		return error;

	error = 0;
	if (len <= 0)	/* if nothing being freed */
		return error;
	rt = XFS_IS_REALTIME_INODE(ip);
	startoffset_fsb	= XFS_B_TO_FSB(mp, offset);
	endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);

	/* wait for the completion of any pending DIOs */
	inode_dio_wait(VFS_I(ip));

	rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
	ioffset = offset & ~(rounding - 1);
	error = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
					      ioffset, -1);
	if (error)
		goto out;
	truncate_pagecache_range(VFS_I(ip), ioffset, -1);

	/*
	 * Need to zero the stuff we're not freeing, on disk.
	 * If it's a realtime file & can't use unwritten extents then we
	 * actually need to zero the extent edges.  Otherwise xfs_bunmapi
	 * will take care of it for us.
	 */
	if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
		nimap = 1;
		error = xfs_bmapi_read(ip, startoffset_fsb, 1,
					&imap, &nimap, 0);
		if (error)
			goto out;
		ASSERT(nimap == 0 || nimap == 1);
		if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
			xfs_daddr_t	block;

			ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
			block = imap.br_startblock;
			mod = do_div(block, mp->m_sb.sb_rextsize);
			if (mod)
				startoffset_fsb += mp->m_sb.sb_rextsize - mod;
		}
		nimap = 1;
		error = xfs_bmapi_read(ip, endoffset_fsb - 1, 1,
					&imap, &nimap, 0);
		if (error)
			goto out;
		ASSERT(nimap == 0 || nimap == 1);
		if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
			ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
			mod++;
			if (mod && (mod != mp->m_sb.sb_rextsize))
				endoffset_fsb -= mod;
		}
	}
	if ((done = (endoffset_fsb <= startoffset_fsb)))
		/*
		 * One contiguous piece to clear
		 */
		error = xfs_zero_remaining_bytes(ip, offset, offset + len - 1);
	else {
		/*
		 * Some full blocks, possibly two pieces to clear
		 */
		if (offset < XFS_FSB_TO_B(mp, startoffset_fsb))
			error = xfs_zero_remaining_bytes(ip, offset,
				XFS_FSB_TO_B(mp, startoffset_fsb) - 1);
		if (!error &&
		    XFS_FSB_TO_B(mp, endoffset_fsb) < offset + len)
			error = xfs_zero_remaining_bytes(ip,
				XFS_FSB_TO_B(mp, endoffset_fsb),
				offset + len - 1);
	}

	/*
	 * free file space until done or until there is an error
	 */
	resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
	while (!error && !done) {

		/*
		 * allocate and setup the transaction. Allow this
		 * transaction to dip into the reserve blocks to ensure
		 * the freeing of the space succeeds at ENOSPC.
		 */
		tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
		tp->t_flags |= XFS_TRANS_RESERVE;
		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write, resblks, 0);

		/*
		 * check for running out of space
		 */
		if (error) {
			/*
			 * Free the transaction structure.
			 */
			ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp));
			xfs_trans_cancel(tp, 0);
			break;
		}
		xfs_ilock(ip, XFS_ILOCK_EXCL);
		error = xfs_trans_reserve_quota(tp, mp,
				ip->i_udquot, ip->i_gdquot, ip->i_pdquot,
				resblks, 0, XFS_QMOPT_RES_REGBLKS);
		if (error)
			goto error1;

		xfs_trans_ijoin(tp, ip, 0);

		/*
		 * issue the bunmapi() call to free the blocks
		 */
		xfs_bmap_init(&free_list, &firstfsb);
		error = xfs_bunmapi(tp, ip, startoffset_fsb,
				  endoffset_fsb - startoffset_fsb,
				  0, 2, &firstfsb, &free_list, &done);
		if (error) {
			goto error0;
		}

		/*
		 * complete the transaction
		 */
		error = xfs_bmap_finish(&tp, &free_list, &committed);
		if (error) {
			goto error0;
		}

		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
		xfs_iunlock(ip, XFS_ILOCK_EXCL);
	}

 out:
	return error;

 error0:
	xfs_bmap_cancel(&free_list);
 error1:
	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	goto out;
}
Пример #6
0
int
xfs_attr_set(
	struct xfs_inode	*dp,
	const unsigned char	*name,
	unsigned char		*value,
	int			valuelen,
	int			flags)
{
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_buf		*leaf_bp = NULL;
	struct xfs_da_args	args;
	struct xfs_trans_res	tres;
	int			rsvd = (flags & ATTR_ROOT) != 0;
	int			error, err2, local;

	XFS_STATS_INC(mp, xs_attr_set);

	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
		return -EIO;

	error = xfs_attr_args_init(&args, dp, name, flags);
	if (error)
		return error;

	args.value = value;
	args.valuelen = valuelen;
	args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
	args.total = xfs_attr_calc_size(&args, &local);

	error = xfs_qm_dqattach(dp);
	if (error)
		return error;

	/*
	 * If the inode doesn't have an attribute fork, add one.
	 * (inode must not be locked when we call this routine)
	 */
	if (XFS_IFORK_Q(dp) == 0) {
		int sf_size = sizeof(xfs_attr_sf_hdr_t) +
			XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen, valuelen);

		error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
		if (error)
			return error;
	}

	tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
			 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
	tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
	tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;

	/*
	 * Root fork attributes can use reserved data blocks for this
	 * operation if necessary
	 */
	error = xfs_trans_alloc(mp, &tres, args.total, 0,
			rsvd ? XFS_TRANS_RESERVE : 0, &args.trans);
	if (error)
		return error;

	xfs_ilock(dp, XFS_ILOCK_EXCL);
	error = xfs_trans_reserve_quota_nblks(args.trans, dp, args.total, 0,
				rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
				       XFS_QMOPT_RES_REGBLKS);
	if (error) {
		xfs_iunlock(dp, XFS_ILOCK_EXCL);
		xfs_trans_cancel(args.trans);
		return error;
	}

	xfs_trans_ijoin(args.trans, dp, 0);

	/*
	 * If the attribute list is non-existent or a shortform list,
	 * upgrade it to a single-leaf-block attribute list.
	 */
	if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
	    (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
	     dp->i_d.di_anextents == 0)) {

		/*
		 * Build initial attribute list (if required).
		 */
		if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
			xfs_attr_shortform_create(&args);

		/*
		 * Try to add the attr to the attribute list in
		 * the inode.
		 */
		error = xfs_attr_shortform_addname(&args);
		if (error != -ENOSPC) {
			/*
			 * Commit the shortform mods, and we're done.
			 * NOTE: this is also the error path (EEXIST, etc).
			 */
			ASSERT(args.trans != NULL);

			/*
			 * If this is a synchronous mount, make sure that
			 * the transaction goes to disk before returning
			 * to the user.
			 */
			if (mp->m_flags & XFS_MOUNT_WSYNC)
				xfs_trans_set_sync(args.trans);

			if (!error && (flags & ATTR_KERNOTIME) == 0) {
				xfs_trans_ichgtime(args.trans, dp,
							XFS_ICHGTIME_CHG);
			}
			err2 = xfs_trans_commit(args.trans);
			xfs_iunlock(dp, XFS_ILOCK_EXCL);

			return error ? error : err2;
		}

		/*
		 * It won't fit in the shortform, transform to a leaf block.
		 * GROT: another possible req'mt for a double-split btree op.
		 */
		error = xfs_attr_shortform_to_leaf(&args, &leaf_bp);
		if (error)
			goto out;
		/*
		 * Prevent the leaf buffer from being unlocked so that a
		 * concurrent AIL push cannot grab the half-baked leaf
		 * buffer and run into problems with the write verifier.
		 */
		xfs_trans_bhold(args.trans, leaf_bp);
		error = xfs_defer_finish(&args.trans);
		if (error)
			goto out;

		/*
		 * Commit the leaf transformation.  We'll need another (linked)
		 * transaction to add the new attribute to the leaf, which
		 * means that we have to hold & join the leaf buffer here too.
		 */
		error = xfs_trans_roll_inode(&args.trans, dp);
		if (error)
			goto out;
		xfs_trans_bjoin(args.trans, leaf_bp);
		leaf_bp = NULL;
	}

	if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
		error = xfs_attr_leaf_addname(&args);
	else
		error = xfs_attr_node_addname(&args);
	if (error)
		goto out;

	/*
	 * If this is a synchronous mount, make sure that the
	 * transaction goes to disk before returning to the user.
	 */
	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(args.trans);

	if ((flags & ATTR_KERNOTIME) == 0)
		xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);

	/*
	 * Commit the last in the sequence of transactions.
	 */
	xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
	error = xfs_trans_commit(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);

	return error;

out:
	if (leaf_bp)
		xfs_trans_brelse(args.trans, leaf_bp);
	if (args.trans)
		xfs_trans_cancel(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);
	return error;
}
Пример #7
0
/*
 * Generic handler routine to remove a name from an attribute list.
 * Transitions attribute list from Btree to shortform as necessary.
 */
int
xfs_attr_remove(
	struct xfs_inode	*dp,
	const unsigned char	*name,
	int			flags)
{
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_da_args	args;
	int			error;

	XFS_STATS_INC(mp, xs_attr_remove);

	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
		return -EIO;

	error = xfs_attr_args_init(&args, dp, name, flags);
	if (error)
		return error;

	/*
	 * we have no control over the attribute names that userspace passes us
	 * to remove, so we have to allow the name lookup prior to attribute
	 * removal to fail.
	 */
	args.op_flags = XFS_DA_OP_OKNOENT;

	error = xfs_qm_dqattach(dp);
	if (error)
		return error;

	/*
	 * Root fork attributes can use reserved data blocks for this
	 * operation if necessary
	 */
	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_attrrm,
			XFS_ATTRRM_SPACE_RES(mp), 0,
			(flags & ATTR_ROOT) ? XFS_TRANS_RESERVE : 0,
			&args.trans);
	if (error)
		return error;

	xfs_ilock(dp, XFS_ILOCK_EXCL);
	/*
	 * No need to make quota reservations here. We expect to release some
	 * blocks not allocate in the common case.
	 */
	xfs_trans_ijoin(args.trans, dp, 0);

	if (!xfs_inode_hasattr(dp)) {
		error = -ENOATTR;
	} else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
		ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
		error = xfs_attr_shortform_remove(&args);
	} else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
		error = xfs_attr_leaf_removename(&args);
	} else {
		error = xfs_attr_node_removename(&args);
	}

	if (error)
		goto out;

	/*
	 * If this is a synchronous mount, make sure that the
	 * transaction goes to disk before returning to the user.
	 */
	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(args.trans);

	if ((flags & ATTR_KERNOTIME) == 0)
		xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);

	/*
	 * Commit the last in the sequence of transactions.
	 */
	xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
	error = xfs_trans_commit(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);

	return error;

out:
	if (args.trans)
		xfs_trans_cancel(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);
	return error;
}
Пример #8
0
/*
 * Generic handler routine to remove a name from an attribute list.
 * Transitions attribute list from Btree to shortform as necessary.
 */
int
xfs_attr_remove(
	struct xfs_inode	*dp,
	const unsigned char	*name,
	int			flags)
{
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_da_args	args;
	struct xfs_bmap_free	flist;
	xfs_fsblock_t		firstblock;
	int			error;

	XFS_STATS_INC(xs_attr_remove);

	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
		return -EIO;

	if (!xfs_inode_hasattr(dp))
		return -ENOATTR;

	error = xfs_attr_args_init(&args, dp, name, flags);
	if (error)
		return error;

	args.firstblock = &firstblock;
	args.flist = &flist;

	/*
	 * we have no control over the attribute names that userspace passes us
	 * to remove, so we have to allow the name lookup prior to attribute
	 * removal to fail.
	 */
	args.op_flags = XFS_DA_OP_OKNOENT;

	error = xfs_qm_dqattach(dp, 0);
	if (error)
		return error;

	/*
	 * Start our first transaction of the day.
	 *
	 * All future transactions during this code must be "chained" off
	 * this one via the trans_dup() call.  All transactions will contain
	 * the inode, and the inode will always be marked with trans_ihold().
	 * Since the inode will be locked in all transactions, we must log
	 * the inode in every transaction to let it float upward through
	 * the log.
	 */
	args.trans = xfs_trans_alloc(mp, XFS_TRANS_ATTR_RM);

	/*
	 * Root fork attributes can use reserved data blocks for this
	 * operation if necessary
	 */

	if (flags & ATTR_ROOT)
		args.trans->t_flags |= XFS_TRANS_RESERVE;

	error = xfs_trans_reserve(args.trans, &M_RES(mp)->tr_attrrm,
				  XFS_ATTRRM_SPACE_RES(mp), 0);
	if (error) {
		xfs_trans_cancel(args.trans);
		return error;
	}

	xfs_ilock(dp, XFS_ILOCK_EXCL);
	/*
	 * No need to make quota reservations here. We expect to release some
	 * blocks not allocate in the common case.
	 */
	xfs_trans_ijoin(args.trans, dp, 0);

	if (!xfs_inode_hasattr(dp)) {
		error = -ENOATTR;
	} else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
		ASSERT(dp->i_afp->if_flags & XFS_IFINLINE);
		error = xfs_attr_shortform_remove(&args);
	} else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
		error = xfs_attr_leaf_removename(&args);
	} else {
		error = xfs_attr_node_removename(&args);
	}

	if (error)
		goto out;

	/*
	 * If this is a synchronous mount, make sure that the
	 * transaction goes to disk before returning to the user.
	 */
	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(args.trans);

	if ((flags & ATTR_KERNOTIME) == 0)
		xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);

	/*
	 * Commit the last in the sequence of transactions.
	 */
	xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
	error = xfs_trans_commit(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);

	return error;

out:
	if (args.trans)
		xfs_trans_cancel(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);
	return error;
}
Пример #9
0
int
xfs_attr_set(
	struct xfs_inode	*dp,
	const unsigned char	*name,
	unsigned char		*value,
	int			valuelen,
	int			flags)
{
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_da_args	args;
	struct xfs_bmap_free	flist;
	struct xfs_trans_res	tres;
	xfs_fsblock_t		firstblock;
	int			rsvd = (flags & ATTR_ROOT) != 0;
	int			error, err2, committed, local;

	XFS_STATS_INC(xs_attr_set);

	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
		return -EIO;

	error = xfs_attr_args_init(&args, dp, name, flags);
	if (error)
		return error;

	args.value = value;
	args.valuelen = valuelen;
	args.firstblock = &firstblock;
	args.flist = &flist;
	args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
	args.total = xfs_attr_calc_size(&args, &local);

	error = xfs_qm_dqattach(dp, 0);
	if (error)
		return error;

	/*
	 * If the inode doesn't have an attribute fork, add one.
	 * (inode must not be locked when we call this routine)
	 */
	if (XFS_IFORK_Q(dp) == 0) {
		int sf_size = sizeof(xfs_attr_sf_hdr_t) +
			XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen, valuelen);

		error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
		if (error)
			return error;
	}

	/*
	 * Start our first transaction of the day.
	 *
	 * All future transactions during this code must be "chained" off
	 * this one via the trans_dup() call.  All transactions will contain
	 * the inode, and the inode will always be marked with trans_ihold().
	 * Since the inode will be locked in all transactions, we must log
	 * the inode in every transaction to let it float upward through
	 * the log.
	 */
	args.trans = xfs_trans_alloc(mp, XFS_TRANS_ATTR_SET);

	/*
	 * Root fork attributes can use reserved data blocks for this
	 * operation if necessary
	 */

	if (rsvd)
		args.trans->t_flags |= XFS_TRANS_RESERVE;

	tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
			 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
	tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
	tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
	error = xfs_trans_reserve(args.trans, &tres, args.total, 0);
	if (error) {
		xfs_trans_cancel(args.trans);
		return error;
	}
	xfs_ilock(dp, XFS_ILOCK_EXCL);

	error = xfs_trans_reserve_quota_nblks(args.trans, dp, args.total, 0,
				rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
				       XFS_QMOPT_RES_REGBLKS);
	if (error) {
		xfs_iunlock(dp, XFS_ILOCK_EXCL);
		xfs_trans_cancel(args.trans);
		return error;
	}

	xfs_trans_ijoin(args.trans, dp, 0);

	/*
	 * If the attribute list is non-existent or a shortform list,
	 * upgrade it to a single-leaf-block attribute list.
	 */
	if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL ||
	    (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS &&
	     dp->i_d.di_anextents == 0)) {

		/*
		 * Build initial attribute list (if required).
		 */
		if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS)
			xfs_attr_shortform_create(&args);

		/*
		 * Try to add the attr to the attribute list in
		 * the inode.
		 */
		error = xfs_attr_shortform_addname(&args);
		if (error != -ENOSPC) {
			/*
			 * Commit the shortform mods, and we're done.
			 * NOTE: this is also the error path (EEXIST, etc).
			 */
			ASSERT(args.trans != NULL);

			/*
			 * If this is a synchronous mount, make sure that
			 * the transaction goes to disk before returning
			 * to the user.
			 */
			if (mp->m_flags & XFS_MOUNT_WSYNC)
				xfs_trans_set_sync(args.trans);

			if (!error && (flags & ATTR_KERNOTIME) == 0) {
				xfs_trans_ichgtime(args.trans, dp,
							XFS_ICHGTIME_CHG);
			}
			err2 = xfs_trans_commit(args.trans);
			xfs_iunlock(dp, XFS_ILOCK_EXCL);

			return error ? error : err2;
		}

		/*
		 * It won't fit in the shortform, transform to a leaf block.
		 * GROT: another possible req'mt for a double-split btree op.
		 */
		xfs_bmap_init(args.flist, args.firstblock);
		error = xfs_attr_shortform_to_leaf(&args);
		if (!error) {
			error = xfs_bmap_finish(&args.trans, args.flist,
						&committed);
		}
		if (error) {
			ASSERT(committed);
			args.trans = NULL;
			xfs_bmap_cancel(&flist);
			goto out;
		}

		/*
		 * bmap_finish() may have committed the last trans and started
		 * a new one.  We need the inode to be in all transactions.
		 */
		if (committed)
			xfs_trans_ijoin(args.trans, dp, 0);

		/*
		 * Commit the leaf transformation.  We'll need another (linked)
		 * transaction to add the new attribute to the leaf.
		 */

		error = xfs_trans_roll(&args.trans, dp);
		if (error)
			goto out;

	}

	if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
		error = xfs_attr_leaf_addname(&args);
	else
		error = xfs_attr_node_addname(&args);
	if (error)
		goto out;

	/*
	 * If this is a synchronous mount, make sure that the
	 * transaction goes to disk before returning to the user.
	 */
	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(args.trans);

	if ((flags & ATTR_KERNOTIME) == 0)
		xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);

	/*
	 * Commit the last in the sequence of transactions.
	 */
	xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
	error = xfs_trans_commit(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);

	return error;

out:
	if (args.trans)
		xfs_trans_cancel(args.trans);
	xfs_iunlock(dp, XFS_ILOCK_EXCL);
	return error;
}
Пример #10
0
/*
 * Truncate file.  Must have write permission and not be a directory.
 */
int
xfs_setattr_size(
	struct xfs_inode	*ip,
	struct iattr		*iattr)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct inode		*inode = VFS_I(ip);
	xfs_off_t		oldsize, newsize;
	struct xfs_trans	*tp;
	int			error;
	uint			lock_flags = 0;
	bool			did_zeroing = false;

	trace_xfs_setattr(ip);

	if (mp->m_flags & XFS_MOUNT_RDONLY)
		return -EROFS;

	if (XFS_FORCED_SHUTDOWN(mp))
		return -EIO;

	error = inode_change_ok(inode, iattr);
	if (error)
		return error;

	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
	ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
	ASSERT(S_ISREG(inode->i_mode));
	ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
		ATTR_MTIME_SET|ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);

	oldsize = inode->i_size;
	newsize = iattr->ia_size;

	/*
	 * Short circuit the truncate case for zero length files.
	 */
	if (newsize == 0 && oldsize == 0 && ip->i_d.di_nextents == 0) {
		if (!(iattr->ia_valid & (ATTR_CTIME|ATTR_MTIME)))
			return 0;

		/*
		 * Use the regular setattr path to update the timestamps.
		 */
		iattr->ia_valid &= ~ATTR_SIZE;
		return xfs_setattr_nonsize(ip, iattr, 0);
	}

	/*
	 * Make sure that the dquots are attached to the inode.
	 */
	error = xfs_qm_dqattach(ip, 0);
	if (error)
		return error;

	/*
	 * Wait for all direct I/O to complete.
	 */
	inode_dio_wait(inode);

	/*
	 * File data changes must be complete before we start the transaction to
	 * modify the inode.  This needs to be done before joining the inode to
	 * the transaction because the inode cannot be unlocked once it is a
	 * part of the transaction.
	 *
	 * Start with zeroing any data beyond EOF that we may expose on file
	 * extension, or zeroing out the rest of the block on a downward
	 * truncate.
	 */
	if (newsize > oldsize) {
		error = xfs_zero_eof(ip, newsize, oldsize, &did_zeroing);
	} else {
		error = iomap_truncate_page(inode, newsize, &did_zeroing,
				&xfs_iomap_ops);
	}

	if (error)
		return error;

	/*
	 * We are going to log the inode size change in this transaction so
	 * any previous writes that are beyond the on disk EOF and the new
	 * EOF that have not been written out need to be written here.  If we
	 * do not write the data out, we expose ourselves to the null files
	 * problem. Note that this includes any block zeroing we did above;
	 * otherwise those blocks may not be zeroed after a crash.
	 */
	if (did_zeroing ||
	    (newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) {
		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
						      ip->i_d.di_size, newsize);
		if (error)
			return error;
	}

	/*
	 * We've already locked out new page faults, so now we can safely remove
	 * pages from the page cache knowing they won't get refaulted until we
	 * drop the XFS_MMAP_EXCL lock after the extent manipulations are
	 * complete. The truncate_setsize() call also cleans partial EOF page
	 * PTEs on extending truncates and hence ensures sub-page block size
	 * filesystems are correctly handled, too.
	 *
	 * We have to do all the page cache truncate work outside the
	 * transaction context as the "lock" order is page lock->log space
	 * reservation as defined by extent allocation in the writeback path.
	 * Hence a truncate can fail with ENOMEM from xfs_trans_alloc(), but
	 * having already truncated the in-memory version of the file (i.e. made
	 * user visible changes). There's not much we can do about this, except
	 * to hope that the caller sees ENOMEM and retries the truncate
	 * operation.
	 */
	truncate_setsize(inode, newsize);

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
	if (error)
		return error;

	lock_flags |= XFS_ILOCK_EXCL;
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, 0);

	/*
	 * Only change the c/mtime if we are changing the size or we are
	 * explicitly asked to change it.  This handles the semantic difference
	 * between truncate() and ftruncate() as implemented in the VFS.
	 *
	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
	 * special case where we need to update the times despite not having
	 * these flags set.  For all other operations the VFS set these flags
	 * explicitly if it wants a timestamp update.
	 */
	if (newsize != oldsize &&
	    !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
		iattr->ia_ctime = iattr->ia_mtime =
			current_fs_time(inode->i_sb);
		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
	}

	/*
	 * The first thing we do is set the size to new_size permanently on
	 * disk.  This way we don't have to worry about anyone ever being able
	 * to look at the data being freed even in the face of a crash.
	 * What we're getting around here is the case where we free a block, it
	 * is allocated to another file, it is written to, and then we crash.
	 * If the new data gets written to the file but the log buffers
	 * containing the free and reallocation don't, then we'd end up with
	 * garbage in the blocks being freed.  As long as we make the new size
	 * permanent before actually freeing any blocks it doesn't matter if
	 * they get written to.
	 */
	ip->i_d.di_size = newsize;
	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

	if (newsize <= oldsize) {
		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
		if (error)
			goto out_trans_cancel;

		/*
		 * Truncated "down", so we're removing references to old data
		 * here - if we delay flushing for a long time, we expose
		 * ourselves unduly to the notorious NULL files problem.  So,
		 * we mark this inode and flush it when the file is closed,
		 * and do not wait the usual (long) time for writeout.
		 */
		xfs_iflags_set(ip, XFS_ITRUNCATED);

		/* A truncate down always removes post-EOF blocks. */
		xfs_inode_clear_eofblocks_tag(ip);
	}

	if (iattr->ia_valid & ATTR_MODE)
		xfs_setattr_mode(ip, iattr);
	if (iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME))
		xfs_setattr_time(ip, iattr);

	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

	XFS_STATS_INC(mp, xs_ig_attrchg);

	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(tp);

	error = xfs_trans_commit(tp);
out_unlock:
	if (lock_flags)
		xfs_iunlock(ip, lock_flags);
	return error;

out_trans_cancel:
	xfs_trans_cancel(tp);
	goto out_unlock;
}
Пример #11
0
/*
 * Prepare two files for range cloning.  Upon a successful return both inodes
 * will have the iolock and mmaplock held, the page cache of the out file will
 * be truncated, and any leases on the out file will have been broken.  This
 * function borrows heavily from xfs_file_aio_write_checks.
 *
 * The VFS allows partial EOF blocks to "match" for dedupe even though it hasn't
 * checked that the bytes beyond EOF physically match. Hence we cannot use the
 * EOF block in the source dedupe range because it's not a complete block match,
 * hence can introduce a corruption into the file that has it's block replaced.
 *
 * In similar fashion, the VFS file cloning also allows partial EOF blocks to be
 * "block aligned" for the purposes of cloning entire files.  However, if the
 * source file range includes the EOF block and it lands within the existing EOF
 * of the destination file, then we can expose stale data from beyond the source
 * file EOF in the destination file.
 *
 * XFS doesn't support partial block sharing, so in both cases we have check
 * these cases ourselves. For dedupe, we can simply round the length to dedupe
 * down to the previous whole block and ignore the partial EOF block. While this
 * means we can't dedupe the last block of a file, this is an acceptible
 * tradeoff for simplicity on implementation.
 *
 * For cloning, we want to share the partial EOF block if it is also the new EOF
 * block of the destination file. If the partial EOF block lies inside the
 * existing destination EOF, then we have to abort the clone to avoid exposing
 * stale data in the destination file. Hence we reject these clone attempts with
 * -EINVAL in this case.
 */
int
xfs_reflink_remap_prep(
	struct file		*file_in,
	loff_t			pos_in,
	struct file		*file_out,
	loff_t			pos_out,
	loff_t			*len,
	unsigned int		remap_flags)
{
	struct inode		*inode_in = file_inode(file_in);
	struct xfs_inode	*src = XFS_I(inode_in);
	struct inode		*inode_out = file_inode(file_out);
	struct xfs_inode	*dest = XFS_I(inode_out);
	bool			same_inode = (inode_in == inode_out);
	ssize_t			ret;

	/* Lock both files against IO */
	ret = xfs_iolock_two_inodes_and_break_layout(inode_in, inode_out);
	if (ret)
		return ret;
	if (same_inode)
		xfs_ilock(src, XFS_MMAPLOCK_EXCL);
	else
		xfs_lock_two_inodes(src, XFS_MMAPLOCK_SHARED, dest,
				XFS_MMAPLOCK_EXCL);

	/* Check file eligibility and prepare for block sharing. */
	ret = -EINVAL;
	/* Don't reflink realtime inodes */
	if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
		goto out_unlock;

	/* Don't share DAX file data for now. */
	if (IS_DAX(inode_in) || IS_DAX(inode_out))
		goto out_unlock;

	ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
			len, remap_flags);
	if (ret < 0 || *len == 0)
		goto out_unlock;

	/* Attach dquots to dest inode before changing block map */
	ret = xfs_qm_dqattach(dest);
	if (ret)
		goto out_unlock;

	/*
	 * Zero existing post-eof speculative preallocations in the destination
	 * file.
	 */
	ret = xfs_reflink_zero_posteof(dest, pos_out);
	if (ret)
		goto out_unlock;

	/* Set flags and remap blocks. */
	ret = xfs_reflink_set_inode_flag(src, dest);
	if (ret)
		goto out_unlock;

	/*
	 * If pos_out > EOF, we may have dirtied blocks between EOF and
	 * pos_out. In that case, we need to extend the flush and unmap to cover
	 * from EOF to the end of the copy length.
	 */
	if (pos_out > XFS_ISIZE(dest)) {
		loff_t	flen = *len + (pos_out - XFS_ISIZE(dest));
		ret = xfs_flush_unmap_range(dest, XFS_ISIZE(dest), flen);
	} else {
		ret = xfs_flush_unmap_range(dest, pos_out, *len);
	}
	if (ret)
		goto out_unlock;

	return 1;
out_unlock:
	xfs_reflink_remap_unlock(file_in, file_out);
	return ret;
}
Пример #12
0
/*
 * Pass in a delayed allocate extent, convert it to real extents;
 * return to the caller the extent we create which maps on top of
 * the originating callers request.
 *
 * Called without a lock on the inode.
 *
 * We no longer bother to look at the incoming map - all we have to
 * guarantee is that whatever we allocate fills the required range.
 */
int
xfs_iomap_write_allocate(
	xfs_inode_t	*ip,
	xfs_off_t	offset,
	size_t		count,
	xfs_bmbt_irec_t *map,
	int		*retmap)
{
	xfs_mount_t	*mp = ip->i_mount;
	xfs_fileoff_t	offset_fsb, last_block;
	xfs_fileoff_t	end_fsb, map_start_fsb;
	xfs_fsblock_t	first_block;
	xfs_bmap_free_t	free_list;
	xfs_filblks_t	count_fsb;
	xfs_bmbt_irec_t	imap;
	xfs_trans_t	*tp;
	int		nimaps, committed;
	int		error = 0;
	int		nres;

	*retmap = 0;

	/*
	 * Make sure that the dquots are there.
	 */
	error = xfs_qm_dqattach(ip, 0);
	if (error)
		return XFS_ERROR(error);

	offset_fsb = XFS_B_TO_FSBT(mp, offset);
	count_fsb = map->br_blockcount;
	map_start_fsb = map->br_startoff;

	XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));

	while (count_fsb != 0) {
		/*
		 * Set up a transaction with which to allocate the
		 * backing store for the file.  Do allocations in a
		 * loop until we get some space in the range we are
		 * interested in.  The other space that might be allocated
		 * is in the delayed allocation extent on which we sit
		 * but before our buffer starts.
		 */

		nimaps = 0;
		while (nimaps == 0) {
			tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
			tp->t_flags |= XFS_TRANS_RESERVE;
			nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
			error = xfs_trans_reserve(tp, nres,
					XFS_WRITE_LOG_RES(mp),
					0, XFS_TRANS_PERM_LOG_RES,
					XFS_WRITE_LOG_COUNT);
			if (error) {
				xfs_trans_cancel(tp, 0);
				return XFS_ERROR(error);
			}
			xfs_ilock(ip, XFS_ILOCK_EXCL);
			xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
			xfs_trans_ihold(tp, ip);

			xfs_bmap_init(&free_list, &first_block);

			/*
			 * it is possible that the extents have changed since
			 * we did the read call as we dropped the ilock for a
			 * while. We have to be careful about truncates or hole
			 * punchs here - we are not allowed to allocate
			 * non-delalloc blocks here.
			 *
			 * The only protection against truncation is the pages
			 * for the range we are being asked to convert are
			 * locked and hence a truncate will block on them
			 * first.
			 *
			 * As a result, if we go beyond the range we really
			 * need and hit an delalloc extent boundary followed by
			 * a hole while we have excess blocks in the map, we
			 * will fill the hole incorrectly and overrun the
			 * transaction reservation.
			 *
			 * Using a single map prevents this as we are forced to
			 * check each map we look for overlap with the desired
			 * range and abort as soon as we find it. Also, given
			 * that we only return a single map, having one beyond
			 * what we can return is probably a bit silly.
			 *
			 * We also need to check that we don't go beyond EOF;
			 * this is a truncate optimisation as a truncate sets
			 * the new file size before block on the pages we
			 * currently have locked under writeback. Because they
			 * are about to be tossed, we don't need to write them
			 * back....
			 */
			nimaps = 1;
			end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
			error = xfs_bmap_last_offset(NULL, ip, &last_block,
							XFS_DATA_FORK);
			if (error)
				goto trans_cancel;

			last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
			if ((map_start_fsb + count_fsb) > last_block) {
				count_fsb = last_block - map_start_fsb;
				if (count_fsb == 0) {
					error = EAGAIN;
					goto trans_cancel;
				}
			}

			/* Go get the actual blocks */
			error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
					XFS_BMAPI_WRITE, &first_block, 1,
					&imap, &nimaps, &free_list, NULL);
			if (error)
				goto trans_cancel;

			error = xfs_bmap_finish(&tp, &free_list, &committed);
			if (error)
				goto trans_cancel;

			error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
			if (error)
				goto error0;

			xfs_iunlock(ip, XFS_ILOCK_EXCL);
		}

		/*
		 * See if we were able to allocate an extent that
		 * covers at least part of the callers request
		 */
		if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
			return xfs_cmn_err_fsblock_zero(ip, &imap);

		if ((offset_fsb >= imap.br_startoff) &&
		    (offset_fsb < (imap.br_startoff +
				   imap.br_blockcount))) {
			*map = imap;
			*retmap = 1;
			XFS_STATS_INC(xs_xstrat_quick);
			return 0;
		}

		/*
		 * So far we have not mapped the requested part of the
		 * file, just surrounding data, try again.
		 */
		count_fsb -= imap.br_blockcount;
		map_start_fsb = imap.br_startoff + imap.br_blockcount;
	}

trans_cancel:
	xfs_bmap_cancel(&free_list);
	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
error0:
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	return XFS_ERROR(error);
}