xfs: move remote symlink target read function to libxfs

Move xfs_readlink_bmap_ilocked to xfs_symlink_remote.c so that the
swapext code can use it to convert a remote format symlink back to
shortform format after a metadata repair.  While we're at it, fix a
broken printf prefix.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_symlink_remote.c

@@ -17,6 +17,9 @@
 #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 +230,77 @@ 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;
+}

fs/xfs/libxfs/xfs_symlink_remote.h

@@ -18,5 +18,6 @@ bool xfs_symlink_hdr_ok(xfs_ino_t ino, uint32_t offset,
 void xfs_symlink_local_to_remote(struct xfs_trans *tp, struct xfs_buf *bp,
 				 struct xfs_inode *ip, struct xfs_ifork *ifp);
 xfs_failaddr_t xfs_symlink_shortform_verify(void *sfp, int64_t size);
+int xfs_symlink_remote_read(struct xfs_inode *ip, char *link);
 
 #endif /* __XFS_SYMLINK_REMOTE_H */

fs/xfs/scrub/symlink.c

@@ -68,7 +68,7 @@ xchk_symlink(
 	}
 
 	/* Remote symlink; must read the contents. */
-	error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
+	error = xfs_symlink_remote_read(sc->ip, sc->buf);
 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
 		return error;
 	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)

fs/xfs/xfs_symlink.c

@@ -26,80 +26,6 @@
 #include "xfs_health.h"
 #include "xfs_symlink_remote.h"
 
-/* ----- Kernel only functions below ----- */
-int
-xfs_readlink_bmap_ilocked(
-	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/Ox%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;
-}
-
 int
 xfs_readlink(
 	struct xfs_inode	*ip,
@@ -141,7 +67,7 @@ xfs_readlink(
 		memcpy(link, ip->i_df.if_data, pathlen + 1);
 		error = 0;
 	} else {
-		error = xfs_readlink_bmap_ilocked(ip, link);
+		error = xfs_symlink_remote_read(ip, link);
 	}
 
 	xfs_iunlock(ip, XFS_ILOCK_SHARED);

fs/xfs/xfs_symlink.h

@@ -10,7 +10,6 @@
 int xfs_symlink(struct mnt_idmap *idmap, struct xfs_inode *dp,
 		struct xfs_name *link_name, const char *target_path,
 		umode_t mode, struct xfs_inode **ipp);
-int xfs_readlink_bmap_ilocked(struct xfs_inode *ip, char *link);
 int xfs_readlink(struct xfs_inode *ip, char *link);
 int xfs_inactive_symlink(struct xfs_inode *ip);