linux-ext4 - [PATCHv2 8/9] ext4: Add strict range checks while freeing blocks

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Date:   Wed, 16 Feb 2022 12:32:50 +0530
From:   Ritesh Harjani <riteshh@...ux.ibm.com>
To:     linux-ext4@...r.kernel.org
Cc:     Jan Kara <jack@...e.cz>, "Theodore Ts'o" <tytso@....edu>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Harshad Shirwadkar <harshadshirwadkar@...il.com>,
        linux-fsdevel@...r.kernel.org,
        Ritesh Harjani <riteshh@...ux.ibm.com>
Subject: [PATCHv2 8/9] 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@...e.cz>
Signed-off-by: Ritesh Harjani <riteshh@...ux.ibm.com>
Reviewed-by: Jan Kara <jack@...e.cz>
---
 fs/ext4/mballoc.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index bb3cfcd545ce..0a95bdb1e07b 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -5930,13 +5930,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
 		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 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
 						 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);
-- 
2.31.1