*
* Map the part of a runlist containing the @vcn of the ntfs inode @ni.
*
- * Return 0 on success and -errno on error.
+ * Return 0 on success and -errno on error. There is one special error code
+ * which is not an error as such. This is -ENOENT. It means that @vcn is out
+ * of bounds of the runlist.
*
* Locking: - The runlist must be locked for writing.
* - This function modifies the runlist.
*/
int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
{
+ VCN end_vcn;
ntfs_inode *base_ni;
- MFT_RECORD *mrec;
+ MFT_RECORD *m;
+ ATTR_RECORD *a;
ntfs_attr_search_ctx *ctx;
runlist_element *rl;
int err = 0;
base_ni = ni;
else
base_ni = ni->ext.base_ntfs_ino;
- mrec = map_mft_record(base_ni);
- if (IS_ERR(mrec))
- return PTR_ERR(mrec);
- ctx = ntfs_attr_get_search_ctx(base_ni, mrec);
+ m = map_mft_record(base_ni);
+ if (IS_ERR(m))
+ return PTR_ERR(m);
+ ctx = ntfs_attr_get_search_ctx(base_ni, m);
if (unlikely(!ctx)) {
err = -ENOMEM;
goto err_out;
}
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
CASE_SENSITIVE, vcn, NULL, 0, ctx);
- if (likely(!err)) {
- rl = ntfs_mapping_pairs_decompress(ni->vol, ctx->attr,
- ni->runlist.rl);
- if (IS_ERR(rl))
- err = PTR_ERR(rl);
- else
- ni->runlist.rl = rl;
+ if (unlikely(err)) {
+ if (err == -ENOENT)
+ err = -EIO;
+ goto err_out;
}
- ntfs_attr_put_search_ctx(ctx);
+ a = ctx->attr;
+ /*
+ * Only decompress the mapping pairs if @vcn is inside it. Otherwise
+ * we get into problems when we try to map an out of bounds vcn because
+ * we then try to map the already mapped runlist fragment and
+ * ntfs_mapping_pairs_decompress() fails.
+ */
+ end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
+ if (unlikely(!a->data.non_resident.lowest_vcn && end_vcn <= 1))
+ end_vcn = ni->allocated_size >> ni->vol->cluster_size_bits;
+ if (unlikely(vcn >= end_vcn)) {
+ err = -ENOENT;
+ goto err_out;
+ }
+ rl = ntfs_mapping_pairs_decompress(ni->vol, a, ni->runlist.rl);
+ if (IS_ERR(rl))
+ err = PTR_ERR(rl);
+ else
+ ni->runlist.rl = rl;
err_out:
+ if (likely(ctx))
+ ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(base_ni);
return err;
}
*
* Map the part of a runlist containing the @vcn of the ntfs inode @ni.
*
- * Return 0 on success and -errno on error.
+ * Return 0 on success and -errno on error. There is one special error code
+ * which is not an error as such. This is -ENOENT. It means that @vcn is out
+ * of bounds of the runlist.
*
* Locking: - The runlist must be unlocked on entry and is unlocked on return.
* - This function takes the runlist lock for writing and modifies the
goto retry_remap;
}
/*
- * -EINVAL and -ENOENT coming from a failed mapping attempt are
- * equivalent to i/o errors for us as they should not happen in
- * our code paths.
+ * -EINVAL coming from a failed mapping attempt is equivalent
+ * to i/o error for us as it should not happen in our code
+ * paths.
*/
- if (err == -EINVAL || err == -ENOENT)
+ if (err == -EINVAL)
err = -EIO;
} else if (!err)
err = -EIO;
new_size = (i_size_read(vi) + vol->cluster_size - 1) &
~(vol->cluster_size - 1);
if (new_size > 0) {
+ runlist_element *rl2;
+
/*
* Will need the page later and since the page lock nests
* outside all ntfs locks, we need to get the page now.
if (IS_ERR(rl)) {
err = PTR_ERR(rl);
ntfs_debug("Failed to allocate cluster%s, error code "
- "%i.\n", (new_size >>
+ "%i.", (new_size >>
vol->cluster_size_bits) > 1 ? "s" : "",
err);
goto page_err_out;
}
+ /* Change the runlist terminator to LCN_ENOENT. */
+ rl2 = rl;
+ while (rl2->length)
+ rl2++;
+ BUG_ON(rl2->lcn != LCN_RL_NOT_MAPPED);
+ rl2->lcn = LCN_ENOENT;
} else {
rl = NULL;
page = NULL;
}
/* Determine the size of the mapping pairs array. */
- mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0);
+ mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0, -1);
if (unlikely(mp_size < 0)) {
err = mp_size;
ntfs_debug("Failed to get size for mapping pairs array, error "
cpu_to_sle64(attr_size);
/* Generate the mapping pairs array into the attribute record. */
err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
- arec_size - mp_ofs, rl, 0, NULL);
+ arec_size - mp_ofs, rl, 0, -1, NULL);
if (unlikely(err)) {
ntfs_debug("Failed to build mapping pairs, error code %i.",
err);