summaryrefslogtreecommitdiffstats
path: root/fs/xfs/libxfs/xfs_symlink_remote.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/xfs/libxfs/xfs_symlink_remote.c')
-rw-r--r--fs/xfs/libxfs/xfs_symlink_remote.c233
1 files changed, 233 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_symlink_remote.c b/fs/xfs/libxfs/xfs_symlink_remote.c
new file mode 100644
index 000000000..bdc777b9e
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_symlink_remote.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * Copyright (c) 2012-2013 Red Hat, Inc.
+ * All rights reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_shared.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_error.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_log.h"
+
+
+/*
+ * Each contiguous block has a header, so it is not just a simple pathlen
+ * to FSB conversion.
+ */
+int
+xfs_symlink_blocks(
+ struct xfs_mount *mp,
+ int pathlen)
+{
+ int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
+
+ return (pathlen + buflen - 1) / buflen;
+}
+
+int
+xfs_symlink_hdr_set(
+ struct xfs_mount *mp,
+ xfs_ino_t ino,
+ uint32_t offset,
+ uint32_t size,
+ struct xfs_buf *bp)
+{
+ struct xfs_dsymlink_hdr *dsl = bp->b_addr;
+
+ if (!xfs_has_crc(mp))
+ return 0;
+
+ memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
+ dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
+ dsl->sl_offset = cpu_to_be32(offset);
+ dsl->sl_bytes = cpu_to_be32(size);
+ uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
+ dsl->sl_owner = cpu_to_be64(ino);
+ dsl->sl_blkno = cpu_to_be64(xfs_buf_daddr(bp));
+ bp->b_ops = &xfs_symlink_buf_ops;
+
+ return sizeof(struct xfs_dsymlink_hdr);
+}
+
+/*
+ * Checking of the symlink header is split into two parts. the verifier does
+ * CRC, location and bounds checking, the unpacking function checks the path
+ * parameters and owner.
+ */
+bool
+xfs_symlink_hdr_ok(
+ xfs_ino_t ino,
+ uint32_t offset,
+ uint32_t size,
+ struct xfs_buf *bp)
+{
+ struct xfs_dsymlink_hdr *dsl = bp->b_addr;
+
+ if (offset != be32_to_cpu(dsl->sl_offset))
+ return false;
+ if (size != be32_to_cpu(dsl->sl_bytes))
+ return false;
+ if (ino != be64_to_cpu(dsl->sl_owner))
+ return false;
+
+ /* ok */
+ return true;
+}
+
+static xfs_failaddr_t
+xfs_symlink_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_dsymlink_hdr *dsl = bp->b_addr;
+
+ if (!xfs_has_crc(mp))
+ return __this_address;
+ if (!xfs_verify_magic(bp, dsl->sl_magic))
+ return __this_address;
+ if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
+ return __this_address;
+ if (xfs_buf_daddr(bp) != be64_to_cpu(dsl->sl_blkno))
+ return __this_address;
+ if (be32_to_cpu(dsl->sl_offset) +
+ be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
+ return __this_address;
+ if (dsl->sl_owner == 0)
+ return __this_address;
+ if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
+ return __this_address;
+
+ return NULL;
+}
+
+static void
+xfs_symlink_read_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_mount;
+ xfs_failaddr_t fa;
+
+ /* no verification of non-crc buffers */
+ if (!xfs_has_crc(mp))
+ return;
+
+ if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
+ xfs_verifier_error(bp, -EFSBADCRC, __this_address);
+ else {
+ fa = xfs_symlink_verify(bp);
+ if (fa)
+ xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+ }
+}
+
+static void
+xfs_symlink_write_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_buf_log_item *bip = bp->b_log_item;
+ xfs_failaddr_t fa;
+
+ /* no verification of non-crc buffers */
+ if (!xfs_has_crc(mp))
+ return;
+
+ fa = xfs_symlink_verify(bp);
+ if (fa) {
+ xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+ return;
+ }
+
+ if (bip) {
+ struct xfs_dsymlink_hdr *dsl = bp->b_addr;
+ dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+ }
+ xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
+}
+
+const struct xfs_buf_ops xfs_symlink_buf_ops = {
+ .name = "xfs_symlink",
+ .magic = { 0, cpu_to_be32(XFS_SYMLINK_MAGIC) },
+ .verify_read = xfs_symlink_read_verify,
+ .verify_write = xfs_symlink_write_verify,
+ .verify_struct = xfs_symlink_verify,
+};
+
+void
+xfs_symlink_local_to_remote(
+ struct xfs_trans *tp,
+ struct xfs_buf *bp,
+ struct xfs_inode *ip,
+ struct xfs_ifork *ifp)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ char *buf;
+
+ xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
+
+ if (!xfs_has_crc(mp)) {
+ bp->b_ops = NULL;
+ memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
+ xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
+ return;
+ }
+
+ /*
+ * As this symlink fits in an inode literal area, it must also fit in
+ * the smallest buffer the filesystem supports.
+ */
+ ASSERT(BBTOB(bp->b_length) >=
+ ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
+
+ bp->b_ops = &xfs_symlink_buf_ops;
+
+ buf = bp->b_addr;
+ buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
+ memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
+ xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
+ ifp->if_bytes - 1);
+}
+
+/*
+ * Verify the in-memory consistency of an inline symlink data fork. This
+ * does not do on-disk format checks.
+ */
+xfs_failaddr_t
+xfs_symlink_shortform_verify(
+ struct xfs_inode *ip)
+{
+ struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
+ char *sfp = (char *)ifp->if_u1.if_data;
+ int size = ifp->if_bytes;
+ char *endp = sfp + size;
+
+ ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
+
+ /*
+ * Zero length symlinks should never occur in memory as they are
+ * never allowed to exist on disk.
+ */
+ if (!size)
+ return __this_address;
+
+ /* No negative sizes or overly long symlink targets. */
+ if (size < 0 || size > XFS_SYMLINK_MAXLEN)
+ return __this_address;
+
+ /* No NULLs in the target either. */
+ if (memchr(sfp, 0, size - 1))
+ return __this_address;
+
+ /* We /did/ null-terminate the buffer, right? */
+ if (*endp != 0)
+ return __this_address;
+ return NULL;
+}