#include "xfs_log_priv.h"
#include "xfs_trace.h"
#include "xfs_symlink.h"
+#include "xfs_cksum.h"
+#include "xfs_buf_item.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 fsblocks = 0;
+ int len = pathlen;
+
+ do {
+ fsblocks++;
+ len -= XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
+ } while (len > 0);
+
+ ASSERT(fsblocks <= XFS_SYMLINK_MAPS);
+ return fsblocks;
+}
+
+static 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_sb_version_hascrc(&mp->m_sb))
+ return 0;
+
+ 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_uuid);
+ dsl->sl_owner = cpu_to_be64(ino);
+ dsl->sl_blkno = cpu_to_be64(bp->b_bn);
+ 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(
+ 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 (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 bool
+xfs_symlink_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_dsymlink_hdr *dsl = bp->b_addr;
+
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return false;
+ if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
+ return false;
+ if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_uuid))
+ return false;
+ if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
+ return false;
+ if (be32_to_cpu(dsl->sl_offset) +
+ be32_to_cpu(dsl->sl_bytes) >= MAXPATHLEN)
+ return false;
+ if (dsl->sl_owner == 0)
+ return false;
+
+ return true;
+}
+
+static void
+xfs_symlink_read_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+
+ /* no verification of non-crc buffers */
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return;
+
+ if (!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+ offsetof(struct xfs_dsymlink_hdr, sl_crc)) ||
+ !xfs_symlink_verify(bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ }
+}
+
+static void
+xfs_symlink_write_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_buf_log_item *bip = bp->b_fspriv;
+
+ /* no verification of non-crc buffers */
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return;
+
+ if (!xfs_symlink_verify(bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ return;
+ }
+
+ if (bip) {
+ struct xfs_dsymlink_hdr *dsl = bp->b_addr;
+ dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+ }
+ xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+ offsetof(struct xfs_dsymlink_hdr, sl_crc));
+}
+
+const struct xfs_buf_ops xfs_symlink_buf_ops = {
+ .verify_read = xfs_symlink_read_verify,
+ .verify_write = xfs_symlink_write_verify,
+};
void
xfs_symlink_local_to_remote(
struct xfs_inode *ip,
struct xfs_ifork *ifp)
{
- /* remote symlink blocks are not verifiable until CRCs come along */
- bp->b_ops = NULL;
- memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
+ struct xfs_mount *mp = ip->i_mount;
+ char *buf;
+
+ if (!xfs_sb_version_hascrc(&mp->m_sb)) {
+ bp->b_ops = NULL;
+ memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
+ 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);
}
/* ----- Kernel only functions below ----- */
-
STATIC int
xfs_readlink_bmap(
- xfs_inode_t *ip,
- char *link)
+ struct xfs_inode *ip,
+ char *link)
{
- xfs_mount_t *mp = ip->i_mount;
- int pathlen = ip->i_d.di_size;
- int nmaps = XFS_SYMLINK_MAPS;
- xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
- xfs_daddr_t d;
- int byte_cnt;
- int n;
- xfs_buf_t *bp;
- int error = 0;
+ 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_d.di_size;
+ int nmaps = XFS_SYMLINK_MAPS;
+ int byte_cnt;
+ int n;
+ int error = 0;
+ int fsblocks = 0;
+ int offset;
- error = xfs_bmapi_read(ip, 0, XFS_B_TO_FSB(mp, pathlen), mval, &nmaps,
- 0);
+ 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);
- bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0, NULL);
+ bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
+ &xfs_symlink_buf_ops);
if (!bp)
return XFS_ERROR(ENOMEM);
error = bp->b_error;
xfs_buf_relse(bp);
goto out;
}
+ byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
if (pathlen < byte_cnt)
byte_cnt = pathlen;
+
+ cur_chunk = bp->b_addr;
+ if (xfs_sb_version_hascrc(&mp->m_sb)) {
+ if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
+ byte_cnt, bp)) {
+ 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, bp->b_addr, byte_cnt);
+
pathlen -= byte_cnt;
+ offset += byte_cnt;
- memcpy(link, bp->b_addr, byte_cnt);
xfs_buf_relse(bp);
}
+ ASSERT(pathlen == 0);
link[ip->i_d.di_size] = '\0';
error = 0;
int
xfs_readlink(
- xfs_inode_t *ip,
+ struct xfs_inode *ip,
char *link)
{
- xfs_mount_t *mp = ip->i_mount;
+ struct xfs_mount *mp = ip->i_mount;
xfs_fsize_t pathlen;
int error = 0;
int
xfs_symlink(
- xfs_inode_t *dp,
+ struct xfs_inode *dp,
struct xfs_name *link_name,
const char *target_path,
umode_t mode,
- xfs_inode_t **ipp)
+ struct xfs_inode **ipp)
{
- xfs_mount_t *mp = dp->i_mount;
- xfs_trans_t *tp;
- xfs_inode_t *ip;
- int error;
+ struct xfs_mount *mp = dp->i_mount;
+ struct xfs_trans *tp = NULL;
+ struct xfs_inode *ip = NULL;
+ int error = 0;
int pathlen;
- xfs_bmap_free_t free_list;
+ struct xfs_bmap_free free_list;
xfs_fsblock_t first_block;
- bool unlock_dp_on_error = false;
+ bool unlock_dp_on_error = false;
uint cancel_flags;
int committed;
xfs_fileoff_t first_fsb;
xfs_filblks_t fs_blocks;
int nmaps;
- xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
+ struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
xfs_daddr_t d;
const char *cur_chunk;
int byte_cnt;
uint resblks;
*ipp = NULL;
- error = 0;
- ip = NULL;
- tp = NULL;
trace_xfs_symlink(dp, link_name);
xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
} else {
+ int offset;
+
first_fsb = 0;
nmaps = XFS_SYMLINK_MAPS;
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);
bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
error = ENOMEM;
goto error2;
}
+ bp->b_ops = &xfs_symlink_buf_ops;
+
+ byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
if (pathlen < byte_cnt) {
byte_cnt = pathlen;
}
- pathlen -= byte_cnt;
- memcpy(bp->b_addr, cur_chunk, byte_cnt);
+ 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_log_buf(tp, bp, 0, byte_cnt - 1);
+ xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
+ (char *)bp->b_addr);
}
}
/*
* Free a symlink that has blocks associated with it.
*/
-STATIC int
+int
xfs_inactive_symlink_rmt(
xfs_inode_t *ip,
xfs_trans_t **tpp)
done = 0;
xfs_bmap_init(&free_list, &first_block);
nmaps = ARRAY_SIZE(mval);
- error = xfs_bmapi_read(ip, 0, XFS_B_TO_FSB(mp, size),
+ error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
mval, &nmaps, 0);
if (error)
goto error0;
/*
- * Invalidate the block(s).
+ * Invalidate the block(s). No validation is done.
*/
for (i = 0; i < nmaps; i++) {
bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
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