ext4: add missing xattr hash update

When updating an extended attribute, if the padded value sizes are the
same, a shortcut is taken to avoid the bulk of the work. This was fine
until the xattr hash update was moved inside ext4_xattr_set_entry().
With that change, the hash update got missed in the shortcut case.

Thanks to ZhangYi (yizhang089@gmail.com) for root causing the problem.

Fixes: daf8328172df ("ext4: eliminate xattr entry e_hash recalculation for removes")

Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 82a5af9f66685a6165a59a1f0c6ba603dd332e8b..3dd9701684488627d26294dd0489323b72afbba8 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1543,7 +1543,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
                        /* Clear padding bytes. */
                        memset(val + i->value_len, 0, new_size - i->value_len);
                }
-               return 0;
+               goto update_hash;
        }
 
        /* Compute min_offs and last. */
@@ -1707,6 +1707,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
                here->e_value_size = cpu_to_le32(i->value_len);
        }
 
+update_hash:
        if (i->value) {
                __le32 hash = 0;
 
@@ -1725,7 +1726,8 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
                                                     here->e_name_len,
                                                     &crc32c_hash, 1);
                } else if (is_block) {
-                       __le32 *value = s->base + min_offs - new_size;
+                       __le32 *value = s->base + le16_to_cpu(
+                                                       here->e_value_offs);
 
                        hash = ext4_xattr_hash_entry(here->e_name,
                                                     here->e_name_len, value,