ext4: don't update checksum of new initialized bitmaps
authorTheodore Ts'o <tytso@mit.edu>
Mon, 19 Feb 2018 19:16:47 +0000 (14:16 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 24 Apr 2018 07:34:12 +0000 (09:34 +0200)
commit 044e6e3d74a3d7103a0c8a9305dfd94d64000660 upstream.

When reading the inode or block allocation bitmap, if the bitmap needs
to be initialized, do not update the checksum in the block group
descriptor.  That's because we're not set up to journal those changes.
Instead, just set the verified bit on the bitmap block, so that it's
not necessary to validate the checksum.

When a block or inode allocation actually happens, at that point the
checksum will be calculated, and update of the bg descriptor block
will be properly journalled.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ext4/balloc.c
fs/ext4/ialloc.c

index e04ec868e37e71d3e82529eeb68f449c284b47c6..176b4b27a27a0edb71cd9f137d52bed0a2fd4b0c 100644 (file)
@@ -242,8 +242,6 @@ static int ext4_init_block_bitmap(struct super_block *sb,
         */
        ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
                             sb->s_blocksize * 8, bh->b_data);
-       ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
-       ext4_group_desc_csum_set(sb, block_group, gdp);
        return 0;
 }
 
@@ -447,6 +445,7 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
                err = ext4_init_block_bitmap(sb, bh, block_group, desc);
                set_bitmap_uptodate(bh);
                set_buffer_uptodate(bh);
+               set_buffer_verified(bh);
                ext4_unlock_group(sb, block_group);
                unlock_buffer(bh);
                if (err) {
index 2d94e8524839a42160bb1d4f2511ddd55867924f..79a9a1bddafcb785097d91cc3ee1cdef85387a12 100644 (file)
@@ -63,44 +63,6 @@ void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
                memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
 }
 
-/* Initializes an uninitialized inode bitmap */
-static int ext4_init_inode_bitmap(struct super_block *sb,
-                                      struct buffer_head *bh,
-                                      ext4_group_t block_group,
-                                      struct ext4_group_desc *gdp)
-{
-       struct ext4_group_info *grp;
-       struct ext4_sb_info *sbi = EXT4_SB(sb);
-       J_ASSERT_BH(bh, buffer_locked(bh));
-
-       /* If checksum is bad mark all blocks and inodes use to prevent
-        * allocation, essentially implementing a per-group read-only flag. */
-       if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
-               grp = ext4_get_group_info(sb, block_group);
-               if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
-                       percpu_counter_sub(&sbi->s_freeclusters_counter,
-                                          grp->bb_free);
-               set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
-               if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
-                       int count;
-                       count = ext4_free_inodes_count(sb, gdp);
-                       percpu_counter_sub(&sbi->s_freeinodes_counter,
-                                          count);
-               }
-               set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
-               return -EFSBADCRC;
-       }
-
-       memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
-       ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
-                       bh->b_data);
-       ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
-                                  EXT4_INODES_PER_GROUP(sb) / 8);
-       ext4_group_desc_csum_set(sb, block_group, gdp);
-
-       return 0;
-}
-
 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
 {
        if (uptodate) {
@@ -184,17 +146,14 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 
        ext4_lock_group(sb, block_group);
        if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
-               err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
+               memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
+               ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
+                                    sb->s_blocksize * 8, bh->b_data);
                set_bitmap_uptodate(bh);
                set_buffer_uptodate(bh);
                set_buffer_verified(bh);
                ext4_unlock_group(sb, block_group);
                unlock_buffer(bh);
-               if (err) {
-                       ext4_error(sb, "Failed to init inode bitmap for group "
-                                  "%u: %d", block_group, err);
-                       goto out;
-               }
                return bh;
        }
        ext4_unlock_group(sb, block_group);