ext4: verify and calculate checksums for extent tree blocks

[profile/ivi/kernel-adaptation-intel-automotive.git] / fs / ext4 / extents.c

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 8c1334e..6f3b49b 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -52,6 +52,46 @@
 #define EXT4_EXT_MARK_UNINIT1  0x2  /* mark first half uninitialized */
 #define EXT4_EXT_MARK_UNINIT2  0x4  /* mark second half uninitialized */
 
+static __le32 ext4_extent_block_csum(struct inode *inode,
+                                    struct ext4_extent_header *eh)
+{
+       struct ext4_inode_info *ei = EXT4_I(inode);
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+       __u32 csum;
+
+       csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
+                          EXT4_EXTENT_TAIL_OFFSET(eh));
+       return cpu_to_le32(csum);
+}
+
+static int ext4_extent_block_csum_verify(struct inode *inode,
+                                        struct ext4_extent_header *eh)
+{
+       struct ext4_extent_tail *et;
+
+       if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+               EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+               return 1;
+
+       et = find_ext4_extent_tail(eh);
+       if (et->et_checksum != ext4_extent_block_csum(inode, eh))
+               return 0;
+       return 1;
+}
+
+static void ext4_extent_block_csum_set(struct inode *inode,
+                                      struct ext4_extent_header *eh)
+{
+       struct ext4_extent_tail *et;
+
+       if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+               EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+               return;
+
+       et = find_ext4_extent_tail(eh);
+       et->et_checksum = ext4_extent_block_csum(inode, eh);
+}
+
 static int ext4_split_extent(handle_t *handle,
                                struct inode *inode,
                                struct ext4_ext_path *path,
@@ -117,6 +157,7 @@ static int __ext4_ext_dirty(const char *where, unsigned int line,
 {
        int err;
        if (path->p_bh) {
+               ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
                /* path points to block */
                err = __ext4_handle_dirty_metadata(where, line, handle,
                                                   inode, path->p_bh);
@@ -391,6 +432,12 @@ static int __ext4_ext_check(const char *function, unsigned int line,
                error_msg = "invalid extent entries";
                goto corrupted;
        }
+       /* Verify checksum on non-root extent tree nodes */
+       if (ext_depth(inode) != depth &&
+           !ext4_extent_block_csum_verify(inode, eh)) {
+               error_msg = "extent tree corrupted";
+               goto corrupted;
+       }
        return 0;
 
 corrupted:
@@ -930,6 +977,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                le16_add_cpu(&neh->eh_entries, m);
        }
 
+       ext4_extent_block_csum_set(inode, neh);
        set_buffer_uptodate(bh);
        unlock_buffer(bh);
 
@@ -1008,6 +1056,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                                sizeof(struct ext4_extent_idx) * m);
                        le16_add_cpu(&neh->eh_entries, m);
                }
+               ext4_extent_block_csum_set(inode, neh);
                set_buffer_uptodate(bh);
                unlock_buffer(bh);
 
@@ -1105,6 +1154,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        else
                neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
        neh->eh_magic = EXT4_EXT_MAGIC;
+       ext4_extent_block_csum_set(inode, neh);
        set_buffer_uptodate(bh);
        unlock_buffer(bh);