[PATCH 06/11] fs/ntfs3: Undo critial modificatins to keep directory consistency

From: Konstantin Komarov
Date: Wed Feb 15 2023 - 08:37:29 EST


Affect xfstest 320.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
---
 fs/ntfs3/index.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
index 9fefeac5fe7e..5d1ec0124137 100644
--- a/fs/ntfs3/index.c
+++ b/fs/ntfs3/index.c
@@ -1778,10 +1778,11 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
     struct indx_node *n1 = fnd->nodes[level];
     struct INDEX_HDR *hdr1 = &n1->index->ihdr;
     struct INDEX_HDR *hdr2;
-    u32 to_copy, used;
+    u32 to_copy, used, used1;
     CLST new_vbn;
     __le64 t_vbn, *sub_vbn;
     u16 sp_size;
+    void *hdr1_saved = NULL;

     /* Try the most easy case. */
     e = fnd->level - 1 == level ? fnd->de[level] : NULL;
@@ -1814,6 +1815,13 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
         return -ENOMEM;
     memcpy(up_e, sp, sp_size);

+    used1 = le32_to_cpu(hdr1->used);
+    hdr1_saved = kmemdup(hdr1, used1, GFP_NOFS);
+    if (!hdr1_saved) {
+        err = -ENOMEM;
+        goto out;
+    }
+
     if (!hdr1->flags) {
         up_e->flags |= NTFS_IE_HAS_SUBNODES;
         up_e->size = cpu_to_le16(sp_size + sizeof(u64));
@@ -1846,7 +1854,7 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
     hdr_insert_head(hdr2, de_t, to_copy);

     /* Remove all entries (sp including) from hdr1. */
-    used = le32_to_cpu(hdr1->used) - to_copy - sp_size;
+    used = used1 - to_copy - sp_size;
     memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));
     hdr1->used = cpu_to_le32(used);

@@ -1876,8 +1884,6 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
     if (!level) {
         /* Insert in root. */
         err = indx_insert_into_root(indx, ni, up_e, NULL, ctx, fnd, 0);
-        if (err)
-            goto out;
     } else {
         /*
          * The target buffer's parent is another index buffer.
@@ -1885,12 +1891,20 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
          */
         err = indx_insert_into_buffer(indx, ni, root, up_e, ctx,
                           level - 1, fnd);
-        if (err)
-            goto out;
+    }
+
+    if (err) {
+        /*
+         * Undo critical operations.
+         */
+        indx_mark_free(indx, ni, new_vbn >> indx->idx2vbn_bits);
+        memcpy(hdr1, hdr1_saved, used1);
+        indx_write(indx, ni, n1, 0);
     }

 out:
     kfree(up_e);
+    kfree(hdr1_saved);

     return err;
 }
@@ -1949,16 +1963,12 @@ int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
          */
         err = indx_insert_into_root(indx, ni, new_de, fnd->root_de, ctx,
                         fnd, undo);
-        if (err)
-            goto out;
     } else {
         /*
          * Found a leaf buffer, so we'll insert the new entry into it.
          */
         err = indx_insert_into_buffer(indx, ni, root, new_de, ctx,
                           fnd->level - 1, fnd);
-        if (err)
-            goto out;
     }

 out:
--
2.34.1