On Tue, Apr 29, 2014 at 07:04:59AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> Currently the attribute code will not detect and correct errors in
> the attribute tree. It also fails to validate the CRCs and headers
> on remote attribute blocks. Ensure that all the attribute blocks are
> CRC checked and that the processing functions understand the correct
> block formats for decoding.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
> repair/attr_repair.c | 45 +++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 37 insertions(+), 8 deletions(-)
>
> diff --git a/repair/attr_repair.c b/repair/attr_repair.c
> index ba85ac2..9b57960 100644
> --- a/repair/attr_repair.c
> +++ b/repair/attr_repair.c
> @@ -604,6 +604,7 @@ verify_da_path(xfs_mount_t *mp,
> libxfs_putbuf(bp);
> return(1);
> }
> +
> /*
> * update cursor, write out the *current* level if
> * required. don't write out the descendant level
> @@ -615,6 +616,8 @@ verify_da_path(xfs_mount_t *mp,
> libxfs_writebuf(cursor->level[this_level].bp, 0);
> else
> libxfs_putbuf(cursor->level[this_level].bp);
> +
> + /* switch cursor to point at the new buffer we just read */
> cursor->level[this_level].bp = bp;
> cursor->level[this_level].dirty = 0;
> cursor->level[this_level].bno = dabno;
> @@ -624,6 +627,14 @@ verify_da_path(xfs_mount_t *mp,
> cursor->level[this_level].n = newnode;
> #endif
> entry = cursor->level[this_level].index = 0;
> +
> + /*
> + * We want to rewrite the buffer a CRC error seeing as it
Nit: ^ "on a CRC error ..." ?
> + * contains what appears to be a valid node block, but only if
> + * we are fixing errors.
> + */
> + if (bp->b_error == EFSBADCRC && !no_modify)
> + cursor->level[this_level].dirty++;
> }
> /*
> * ditto for block numbers
> @@ -974,6 +985,10 @@ rmtval_get(xfs_mount_t *mp, xfs_ino_t ino, blkmap_t *blkmap,
> xfs_dfsbno_t bno;
> xfs_buf_t *bp;
> int clearit = 0, i = 0, length = 0, amountdone = 0;
> + int hdrsize = 0;
> +
> + if (xfs_sb_version_hascrc(&mp->m_sb))
> + hdrsize = sizeof(struct xfs_attr3_rmt_hdr);
>
> /* ASSUMPTION: valuelen is a valid number, so use it for looping */
> /* Note that valuelen is not a multiple of blocksize */
> @@ -986,16 +1001,26 @@ rmtval_get(xfs_mount_t *mp, xfs_ino_t ino, blkmap_t *blkmap,
> break;
> }
> bp = libxfs_readbuf(mp->m_dev, XFS_FSB_TO_DADDR(mp, bno),
> - XFS_FSB_TO_BB(mp, 1), 0, NULL);
> + XFS_FSB_TO_BB(mp, 1), 0,
> + &xfs_attr3_rmt_buf_ops);
> if (!bp) {
> do_warn(
> _("can't read remote block for attributes of inode %" PRIu64 "\n"), ino);
> clearit = 1;
> break;
> }
> +
> + if (bp->b_error == EFSBADCRC || bp->b_error == EFSCORRUPTED) {
> + do_warn(
> + _("Corrupt remote block for attributes of inode %" PRIu64 "\n"), ino);
> + clearit = 1;
> + break;
> + }
> +
> ASSERT(mp->m_sb.sb_blocksize == XFS_BUF_COUNT(bp));
> - length = MIN(XFS_BUF_COUNT(bp), valuelen - amountdone);
> - memmove(value, XFS_BUF_PTR(bp), length);
> +
> + length = MIN(XFS_BUF_COUNT(bp) - hdrsize, valuelen - amountdone);
> + memmove(value, XFS_BUF_PTR(bp) + hdrsize, length);
> amountdone += length;
> value += length;
> i++;
> @@ -1143,7 +1168,6 @@ process_leaf_attr_block(
>
> xfs_attr3_leaf_hdr_from_disk(&leafhdr, leaf);
> clearit = usedbs = 0;
> - *repair = 0;
> firstb = mp->m_sb.sb_blocksize;
> stop = xfs_attr3_leaf_hdr_size(leaf);
>
> @@ -1320,13 +1344,16 @@ process_leaf_attr_level(xfs_mount_t *mp,
> }
>
> bp = libxfs_readbuf(mp->m_dev, XFS_FSB_TO_DADDR(mp, dev_bno),
> - XFS_FSB_TO_BB(mp, 1), 0, NULL);
> + XFS_FSB_TO_BB(mp, 1), 0,
> + &xfs_attr3_leaf_buf_ops);
> if (!bp) {
> do_warn(
> _("can't read file block %u (fsbno %" PRIu64 ") for attribute fork of inode %" PRIu64 "\n"),
> da_bno, dev_bno, ino);
> goto error_out;
> }
> + if (bp->b_error == EFSBADCRC)
> + repair++;
>
> leaf = bp->b_addr;
> xfs_attr3_leaf_hdr_from_disk(&leafhdr, leaf);
> @@ -1382,9 +1409,9 @@ process_leaf_attr_level(xfs_mount_t *mp,
>
> current_hashval = greatest_hashval;
>
> - if (repair && !no_modify)
> + if (repair && !no_modify)
> libxfs_writebuf(bp, 0);
> - else
> + else
> libxfs_putbuf(bp);
> } while (da_bno != 0);
>
> @@ -1512,6 +1539,8 @@ process_longform_attr(
> ino);
> return(1);
> }
> + if (bp->b_error == EFSBADCRC)
> + (*repair)++;
>
> /* verify leaf block */
> leaf = (xfs_attr_leafblock_t *)XFS_BUF_PTR(bp);
> @@ -1555,7 +1584,7 @@ process_longform_attr(
> case XFS_DA_NODE_MAGIC: /* btree-form attribute */
> case XFS_DA3_NODE_MAGIC:
> /* must do this now, to release block 0 before the traversal */
> - if (repairlinks) {
> + if (*repair || repairlinks) {
> *repair = 1;
> libxfs_writebuf(bp, 0);
> } else
repairlinks incorporates a !no_modify check, but *repair does not. It's
incremented unconditionally if we find a CRC error. I suspect this means
we now need a !no_modify check for the writebuf/putbuf check here, as is
done in the alternate path at the end of the function.
Brian
> --
> 1.9.0
>
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