ext4: add strict range checks while freeing blocks

Currently ext4_mb_clear_bb() & ext4_group_add_blocks() only checks
whether the given block ranges (which is to be freed) belongs to any FS
metadata blocks or not, of the block's respective block group.
But to detect any FS error early, it is better to add more strict
checkings in those functions which checks whether the given blocks
belongs to any critical FS metadata or not within system-zone.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/ddd9143d064774e32d6364a99667817c6e8bfdc0.1644992610.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index bb3cfcd..0a95bdb 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -5930,13 +5930,7 @@ do_more:
                goto error_return;
        }
 
-       if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
-           in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
-           in_range(block, ext4_inode_table(sb, gdp),
-                    sbi->s_itb_per_group) ||
-           in_range(block + count - 1, ext4_inode_table(sb, gdp),
-                    sbi->s_itb_per_group)) {
-
+       if (!ext4_inode_block_valid(inode, block, count)) {
                ext4_error(sb, "Freeing blocks in system zone - "
                           "Block = %llu, count = %lu", block, count);
                /* err = 0. ext4_std_error should be a no op */
@@ -6007,7 +6001,7 @@ do_more:
                                                 NULL);
                        if (err && err != -EOPNOTSUPP)
                                ext4_msg(sb, KERN_WARNING, "discard request in"
-                                        " group:%d block:%d count:%lu failed"
+                                        " group:%u block:%d count:%lu failed"
                                         " with %d", block_group, bit, count,
                                         err);
                } else
@@ -6220,11 +6214,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
                goto error_return;
        }
 
-       if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
-           in_range(ext4_inode_bitmap(sb, desc), block, count) ||
-           in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
-           in_range(block + count - 1, ext4_inode_table(sb, desc),
-                    sbi->s_itb_per_group)) {
+       if (!ext4_sb_block_valid(sb, NULL, block, count)) {
                ext4_error(sb, "Adding blocks in system zones - "
                           "Block = %llu, count = %lu",
                           block, count);