Merge tag 'symlink-cleanups-6.9_2024-02-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-6.9-mergeC

xfs: clean up symbolic link code

This series cleans up a few bits of the symbolic link code as needed for
future projects.  Online repair requires the ability to commit fixed
fork-based filesystem metadata such as directories, xattrs, and symbolic
links atomically, so we need to rearrange the symlink code before we
land the atomic extent swapping.

Accomplish this by moving the remote symlink target block code and
declarations to xfs_symlink_remote.[ch].

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

* tag 'symlink-cleanups-6.9_2024-02-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: move symlink target write function to libxfs
  xfs: move remote symlink target read function to libxfs
  xfs: move xfs_symlink_remote.c declarations to xfs_symlink_remote.h

9 files changed, 192 insertions, 155 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index d78e02a3b4d6..656c95a22f2e 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -38,6 +38,7 @@
 #include "xfs_iomap.h"
 #include "xfs_health.h"
 #include "xfs_bmap_item.h"
+#include "xfs_symlink_remote.h"
 
 struct kmem_cache		*xfs_bmap_intent_cache;
 
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 3ab0ea133557..7d660a973909 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -26,6 +26,7 @@
 #include "xfs_types.h"
 #include "xfs_errortag.h"
 #include "xfs_health.h"
+#include "xfs_symlink_remote.h"
 
 struct kmem_cache *xfs_ifork_cache;
 
diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h
index cab49e7116ec..dfd61fa8332e 100644
--- a/fs/xfs/libxfs/xfs_shared.h
+++ b/fs/xfs/libxfs/xfs_shared.h
@@ -182,19 +182,6 @@ void	xfs_log_get_max_trans_res(struct xfs_mount *mp,
 #define	XFS_ICHGTIME_CHG	0x2	/* inode field change timestamp */
 #define	XFS_ICHGTIME_CREATE	0x4	/* inode create timestamp */
 
-
-/*
- * Symlink decoding/encoding functions
- */
-int xfs_symlink_blocks(struct xfs_mount *mp, int pathlen);
-int xfs_symlink_hdr_set(struct xfs_mount *mp, xfs_ino_t ino, uint32_t offset,
-			uint32_t size, struct xfs_buf *bp);
-bool xfs_symlink_hdr_ok(xfs_ino_t ino, uint32_t offset,
-			uint32_t size, struct xfs_buf *bp);
-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);
-
 /* Computed inode geometry for the filesystem. */
 struct xfs_ino_geometry {
 	/* Maximum inode count in this filesystem. */
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;
+}
diff --git a/fs/xfs/libxfs/xfs_symlink_remote.h b/fs/xfs/libxfs/xfs_symlink_remote.h
new file mode 100644
index 000000000000..a63bd38ae4fa
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_symlink_remote.h
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+#ifndef __XFS_SYMLINK_REMOTE_H
+#define __XFS_SYMLINK_REMOTE_H
+
+/*
+ * Symlink decoding/encoding functions
+ */
+int xfs_symlink_blocks(struct xfs_mount *mp, int pathlen);
+int xfs_symlink_hdr_set(struct xfs_mount *mp, xfs_ino_t ino, uint32_t offset,
+			uint32_t size, struct xfs_buf *bp);
+bool xfs_symlink_hdr_ok(xfs_ino_t ino, uint32_t offset,
+			uint32_t size, struct xfs_buf *bp);
+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);
+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);
+
+#endif /* __XFS_SYMLINK_REMOTE_H */
diff --git a/fs/xfs/scrub/inode_repair.c b/fs/xfs/scrub/inode_repair.c
index 7e859c412a5b..eab380e95ef4 100644
--- a/fs/xfs/scrub/inode_repair.c
+++ b/fs/xfs/scrub/inode_repair.c
@@ -37,6 +37,7 @@
 #include "xfs_attr_leaf.h"
 #include "xfs_log_priv.h"
 #include "xfs_health.h"
+#include "xfs_symlink_remote.h"
 #include "scrub/xfs_scrub.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
diff --git a/fs/xfs/scrub/symlink.c b/fs/xfs/scrub/symlink.c
index ddff86713df3..d77d8a9598f6 100644
--- a/fs/xfs/scrub/symlink.c
+++ b/fs/xfs/scrub/symlink.c
@@ -13,6 +13,7 @@
 #include "xfs_inode.h"
 #include "xfs_symlink.h"
 #include "xfs_health.h"
+#include "xfs_symlink_remote.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/health.h"
@@ -67,7 +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)
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index fb8c57b9d13d..3e376d24c7c1 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -24,80 +24,7 @@
 #include "xfs_ialloc.h"
 #include "xfs_error.h"
 #include "xfs_health.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;
-}
+#include "xfs_symlink_remote.h"
 
 int
 xfs_readlink(
@@ -140,7 +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);
@@ -166,15 +93,7 @@ xfs_symlink(
 	int			error = 0;
 	int			pathlen;
 	bool                    unlock_dp_on_error = false;
-	xfs_fileoff_t		first_fsb;
 	xfs_filblks_t		fs_blocks;
-	int			nmaps;
-	struct xfs_bmbt_irec	mval[XFS_SYMLINK_MAPS];
-	xfs_daddr_t		d;
-	const char		*cur_chunk;
-	int			byte_cnt;
-	int			n;
-	struct xfs_buf		*bp;
 	prid_t			prid;
 	struct xfs_dquot	*udqp = NULL;
 	struct xfs_dquot	*gdqp = NULL;
@@ -262,62 +181,11 @@ xfs_symlink(
 	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
 
 	resblks -= XFS_IALLOC_SPACE_RES(mp);
-	/*
-	 * 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);
-	} else {
-		int	offset;
-
-		first_fsb = 0;
-		nmaps = XFS_SYMLINK_MAPS;
-
-		error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
-				  XFS_BMAPI_METADATA, resblks, mval, &nmaps);
-		if (error)
-			goto out_trans_cancel;
-
-		resblks -= fs_blocks;
-		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)
-				goto out_trans_cancel;
-			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);
-	}
+	error = xfs_symlink_write_target(tp, ip, target_path, pathlen,
+			fs_blocks, resblks);
+	if (error)
+		goto out_trans_cancel;
+	resblks -= fs_blocks;
 	i_size_write(VFS_I(ip), ip->i_disk_size);
 
 	/*
diff --git a/fs/xfs/xfs_symlink.h b/fs/xfs/xfs_symlink.h
index d1ca1ce62a93..0d29a50e66fd 100644
--- a/fs/xfs/xfs_symlink.h
+++ b/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);