1 files changed, 154 insertions, 1 deletions

diff --git a/fs/xfs/libxfs/xfs_symlink_remote.c b/fs/xfs/libxfs/xfs_symlink_remote.c
index 160aa20aa441..ffb1317a9212 100644
--- a/fs/xfs/libxfs/xfs_symlink_remote.c
+++ b/fs/xfs/libxfs/xfs_symlink_remote.c
@@ -16,7 +16,10 @@
 #include "xfs_trans.h"
 #include "xfs_buf_item.h"
 #include "xfs_log.h"
-
+#include "xfs_symlink_remote.h"
+#include "xfs_bit.h"
+#include "xfs_bmap.h"
+#include "xfs_health.h"
 
 /*
  * Each contiguous block has a header, so it is not just a simple pathlen
@@ -227,3 +230,153 @@ xfs_symlink_shortform_verify(
 		return __this_address;
 	return NULL;
 }
+
+/* Read a remote symlink target into the buffer. */
+int
+xfs_symlink_remote_read(
+	struct xfs_inode	*ip,
+	char			*link)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_bmbt_irec	mval[XFS_SYMLINK_MAPS];
+	struct xfs_buf		*bp;
+	xfs_daddr_t		d;
+	char			*cur_chunk;
+	int			pathlen = ip->i_disk_size;
+	int			nmaps = XFS_SYMLINK_MAPS;
+	int			byte_cnt;
+	int			n;
+	int			error = 0;
+	int			fsblocks = 0;
+	int			offset;
+
+	xfs_assert_ilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
+
+	fsblocks = xfs_symlink_blocks(mp, pathlen);
+	error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
+	if (error)
+		goto out;
+
+	offset = 0;
+	for (n = 0; n < nmaps; n++) {
+		d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
+		byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
+
+		error = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
+				&bp, &xfs_symlink_buf_ops);
+		if (xfs_metadata_is_sick(error))
+			xfs_inode_mark_sick(ip, XFS_SICK_INO_SYMLINK);
+		if (error)
+			return error;
+		byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
+		if (pathlen < byte_cnt)
+			byte_cnt = pathlen;
+
+		cur_chunk = bp->b_addr;
+		if (xfs_has_crc(mp)) {
+			if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
+							byte_cnt, bp)) {
+				xfs_inode_mark_sick(ip, XFS_SICK_INO_SYMLINK);
+				error = -EFSCORRUPTED;
+				xfs_alert(mp,
+"symlink header does not match required off/len/owner (0x%x/0x%x,0x%llx)",
+					offset, byte_cnt, ip->i_ino);
+				xfs_buf_relse(bp);
+				goto out;
+
+			}
+
+			cur_chunk += sizeof(struct xfs_dsymlink_hdr);
+		}
+
+		memcpy(link + offset, cur_chunk, byte_cnt);
+
+		pathlen -= byte_cnt;
+		offset += byte_cnt;
+
+		xfs_buf_relse(bp);
+	}
+	ASSERT(pathlen == 0);
+
+	link[ip->i_disk_size] = '\0';
+	error = 0;
+
+ out:
+	return error;
+}
+
+/* Write the symlink target into the inode. */
+int
+xfs_symlink_write_target(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	const char		*target_path,
+	int			pathlen,
+	xfs_fsblock_t		fs_blocks,
+	uint			resblks)
+{
+	struct xfs_bmbt_irec	mval[XFS_SYMLINK_MAPS];
+	struct xfs_mount	*mp = tp->t_mountp;
+	const char		*cur_chunk;
+	struct xfs_buf		*bp;
+	xfs_daddr_t		d;
+	int			byte_cnt;
+	int			nmaps;
+	int			offset = 0;
+	int			n;
+	int			error;
+
+	/*
+	 * If the symlink will fit into the inode, write it inline.
+	 */
+	if (pathlen <= xfs_inode_data_fork_size(ip)) {
+		xfs_init_local_fork(ip, XFS_DATA_FORK, target_path, pathlen);
+
+		ip->i_disk_size = pathlen;
+		ip->i_df.if_format = XFS_DINODE_FMT_LOCAL;
+		xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
+		return 0;
+	}
+
+	nmaps = XFS_SYMLINK_MAPS;
+	error = xfs_bmapi_write(tp, ip, 0, fs_blocks, XFS_BMAPI_METADATA,
+			resblks, mval, &nmaps);
+	if (error)
+		return error;
+
+	ip->i_disk_size = pathlen;
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+	cur_chunk = target_path;
+	offset = 0;
+	for (n = 0; n < nmaps; n++) {
+		char	*buf;
+
+		d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
+		byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
+		error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
+				BTOBB(byte_cnt), 0, &bp);
+		if (error)
+			return error;
+		bp->b_ops = &xfs_symlink_buf_ops;
+
+		byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
+		byte_cnt = min(byte_cnt, pathlen);
+
+		buf = bp->b_addr;
+		buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset, byte_cnt,
+				bp);
+
+		memcpy(buf, cur_chunk, byte_cnt);
+
+		cur_chunk += byte_cnt;
+		pathlen -= byte_cnt;
+		offset += byte_cnt;
+
+		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
+		xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
+						(char *)bp->b_addr);
+	}
+	ASSERT(pathlen == 0);
+	return 0;
+}