xfs: move remote symlink target read function to libxfs

Source kernel commit: 376b4f0522484f43660dab8e4e92b471863b49f9

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>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

diff --git a/libxfs/xfs_symlink_remote.c b/libxfs/xfs_symlink_remote.c
index 33689ba2eac3d5421d975209344c27eecf04a765..f2e591ea9c9ca584cada4c3e940085f8e5dded32 100644 (file)
--- a/libxfs/xfs_symlink_remote.c
+++ b/libxfs/xfs_symlink_remote.c
@@ -14,6 +14,9 @@
 #include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_symlink_remote.h"
+#include "xfs_bit.h"
+#include "xfs_bmap.h"
+#include "xfs_health.h"
 
 
 /*
@@ -225,3 +228,77 @@ 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;
+}

diff --git a/libxfs/xfs_symlink_remote.h b/libxfs/xfs_symlink_remote.h
index c6f621a0ec053676b8410b643852b4cf198cf5b6..bb83a8b8dfa66ddb3ed0b9a3a946f7dd51a32720 100644 (file)
--- a/libxfs/xfs_symlink_remote.h
+++ b/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 */