aboutsummaryrefslogtreecommitdiff
path: root/fs/ntfs/attrib.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ntfs/attrib.c')
-rw-r--r--fs/ntfs/attrib.c61
1 files changed, 42 insertions, 19 deletions
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index c6b2bb64d65..543d47fa5fc 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -39,15 +39,19 @@
*
* 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;
@@ -58,26 +62,43 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
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;
}
@@ -89,7 +110,9 @@ err_out:
*
* 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
@@ -287,11 +310,11 @@ retry_remap:
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;