[PATCH] ext4: Fix maximum orphan file size check

[PATCH] ext4: Fix maximum orphan file size check

[Jan Kara]

Mikulas reported that e2fsprogs 1.47.4 with 1k fs blocksize by default
creates orphan file of the size the kernel rejects. This is because that
version of e2fsprogs creates 2MB file by default regardless of the block
size and with 1k blocks that's more than the limit of 512 fs blocks.
Fix the check to make kernel accept any file upto those 2MB regardless
of the number of blocks.

Fixes: 7c11c56eb32e ("ext4: align max orphan file size with e2fsprogs limit")
CC: stable@vger.kernel.org
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Link: https://lore.kernel.org/all/e65cdbfe-3ff9-4638-fbd3-4d8f8880966f@redhat.com
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/orphan.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index b4675aa7ea96..7394d04e0fd9 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -576,6 +576,7 @@ int ext4_init_orphan_info(struct super_block *sb)
 	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
 	struct ext4_orphan_block_tail *ot;
 	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
+	loff_t max_size;
 
 	if (!ext4_has_feature_orphan_file(sb))
 		return 0;
@@ -589,8 +590,13 @@ int ext4_init_orphan_info(struct super_block *sb)
 	 * This is just an artificial limit to prevent corrupted fs from
 	 * consuming absurd amounts of memory when pinning blocks of orphan
 	 * file in memory.
+	 *
+	 * e2fsprogs 1.47.4 produces 2MB orphan files by default regardless
+	 * of the number of blocks so that's where the second limit comes from.
 	 */
-	if (inode->i_size > (EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits)) {
+	max_size = max(EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits,
+		       2 << 20);
+	if (inode->i_size > max_size) {
 		ext4_msg(sb, KERN_ERR, "orphan file too big: %llu",
 			 (unsigned long long)inode->i_size);
 		ret = -EFSCORRUPTED;
-- 
2.51.0

Re: [PATCH] ext4: Fix maximum orphan file size check

[sashiko-bot]

> Mikulas reported that e2fsprogs 1.47.4 with 1k fs blocksize by default
> creates orphan file of the size the kernel rejects. This is because that
> version of e2fsprogs creates 2MB file by default regardless of the block
> size and with 1k blocks that's more than the limit of 512 fs blocks.
> Fix the check to make kernel accept any file upto those 2MB regardless
> of the number of blocks.
> 
> Fixes: 7c11c56eb32e ("ext4: align max orphan file size with e2fsprogs limit")
> CC: stable@vger.kernel.org
> Reported-by: Mikulas Patocka <mpatocka@redhat.com>
> Link: https://lore.kernel.org/all/e65cdbfe-3ff9-4638-fbd3-4d8f8880966f@redhat.com
> Signed-off-by: Jan Kara <jack@suse.cz>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261002115040.2783654-2-jack@suse.cz?part=1

Re: [PATCH] ext4: Fix maximum orphan file size check

[Mikulas Patocka]

On Fri, 2 Oct 2026, Jan Kara wrote:

> Mikulas reported that e2fsprogs 1.47.4 with 1k fs blocksize by default
> creates orphan file of the size the kernel rejects. This is because that
> version of e2fsprogs creates 2MB file by default regardless of the block
> size and with 1k blocks that's more than the limit of 512 fs blocks.
> Fix the check to make kernel accept any file upto those 2MB regardless
> of the number of blocks.
> 
> Fixes: 7c11c56eb32e ("ext4: align max orphan file size with e2fsprogs limit")
> CC: stable@vger.kernel.org
> Reported-by: Mikulas Patocka <mpatocka@redhat.com>
> Link: https://lore.kernel.org/all/e65cdbfe-3ff9-4638-fbd3-4d8f8880966f@redhat.com
> Signed-off-by: Jan Kara <jack@suse.cz>

Tested-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>

Mikulas

> ---
>  fs/ext4/orphan.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
> index b4675aa7ea96..7394d04e0fd9 100644
> --- a/fs/ext4/orphan.c
> +++ b/fs/ext4/orphan.c
> @@ -576,6 +576,7 @@ int ext4_init_orphan_info(struct super_block *sb)
>  	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
>  	struct ext4_orphan_block_tail *ot;
>  	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
> +	loff_t max_size;
>  
>  	if (!ext4_has_feature_orphan_file(sb))
>  		return 0;
> @@ -589,8 +590,13 @@ int ext4_init_orphan_info(struct super_block *sb)
>  	 * This is just an artificial limit to prevent corrupted fs from
>  	 * consuming absurd amounts of memory when pinning blocks of orphan
>  	 * file in memory.
> +	 *
> +	 * e2fsprogs 1.47.4 produces 2MB orphan files by default regardless
> +	 * of the number of blocks so that's where the second limit comes from.
>  	 */
> -	if (inode->i_size > (EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits)) {
> +	max_size = max(EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits,
> +		       2 << 20);
> +	if (inode->i_size > max_size) {
>  		ext4_msg(sb, KERN_ERR, "orphan file too big: %llu",
>  			 (unsigned long long)inode->i_size);
>  		ret = -EFSCORRUPTED;
> -- 
> 2.51.0
> 

Re: [PATCH] ext4: Fix maximum orphan file size check

[Baokun Li]

On 2026/10/2 19:50, Jan Kara wrote:
> Mikulas reported that e2fsprogs 1.47.4 with 1k fs blocksize by default
> creates orphan file of the size the kernel rejects. This is because that
> version of e2fsprogs creates 2MB file by default regardless of the block
> size and with 1k blocks that's more than the limit of 512 fs blocks.
> Fix the check to make kernel accept any file upto those 2MB regardless
> of the number of blocks.
>
> Fixes: 7c11c56eb32e ("ext4: align max orphan file size with e2fsprogs limit")
> CC: stable@vger.kernel.org
> Reported-by: Mikulas Patocka <mpatocka@redhat.com>
> Link: https://lore.kernel.org/all/e65cdbfe-3ff9-4638-fbd3-4d8f8880966f@redhat.com
> Signed-off-by: Jan Kara <jack@suse.cz>

Thanks for fixing this.

The problem is only triggered by images created with the problematic
e2fsprogs: 1k-block filesystems between 512MiB and 2GiB, and 2k-block
filesystems between 2GiB and 4GiB.

A more thorough fix would be to rebuild the orphan file with tune2fs.
However, some instances may not get the chance to do that. So I think
it's good to keep the kernel compatible with both versions of
e2fsprogs. Feel free to add:

Reviewed-by: Baokun Li <libaokun@linux.alibaba.com>

> ---
>  fs/ext4/orphan.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
> index b4675aa7ea96..7394d04e0fd9 100644
> --- a/fs/ext4/orphan.c
> +++ b/fs/ext4/orphan.c
> @@ -576,6 +576,7 @@ int ext4_init_orphan_info(struct super_block *sb)
>  	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
>  	struct ext4_orphan_block_tail *ot;
>  	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
> +	loff_t max_size;
>  
>  	if (!ext4_has_feature_orphan_file(sb))
>  		return 0;
> @@ -589,8 +590,13 @@ int ext4_init_orphan_info(struct super_block *sb)
>  	 * This is just an artificial limit to prevent corrupted fs from
>  	 * consuming absurd amounts of memory when pinning blocks of orphan
>  	 * file in memory.
> +	 *
> +	 * e2fsprogs 1.47.4 produces 2MB orphan files by default regardless
> +	 * of the number of blocks so that's where the second limit comes from.
>  	 */
> -	if (inode->i_size > (EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits)) {
> +	max_size = max(EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits,
> +		       2 << 20);
> +	if (inode->i_size > max_size) {
>  		ext4_msg(sb, KERN_ERR, "orphan file too big: %llu",
>  			 (unsigned long long)inode->i_size);
>  		ret = -EFSCORRUPTED;

Re: [PATCH] ext4: Fix maximum orphan file size check

[Zhang Yi]

On 10/2/2026 7:50 PM, Jan Kara wrote:
> Mikulas reported that e2fsprogs 1.47.4 with 1k fs blocksize by default
> creates orphan file of the size the kernel rejects. This is because that
> version of e2fsprogs creates 2MB file by default regardless of the block
> size and with 1k blocks that's more than the limit of 512 fs blocks.
> Fix the check to make kernel accept any file upto those 2MB regardless
> of the number of blocks.
> 
> Fixes: 7c11c56eb32e ("ext4: align max orphan file size with e2fsprogs limit")
> CC: stable@vger.kernel.org
> Reported-by: Mikulas Patocka <mpatocka@redhat.com>
> Link: https://lore.kernel.org/all/e65cdbfe-3ff9-4638-fbd3-4d8f8880966f@redhat.com
> Signed-off-by: Jan Kara <jack@suse.cz>

Looks good to me.

Reviewed-by: Zhang Yi <yi.zhang@huawei.com>

> ---
>  fs/ext4/orphan.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
> index b4675aa7ea96..7394d04e0fd9 100644
> --- a/fs/ext4/orphan.c
> +++ b/fs/ext4/orphan.c
> @@ -576,6 +576,7 @@ int ext4_init_orphan_info(struct super_block *sb)
>  	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
>  	struct ext4_orphan_block_tail *ot;
>  	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
> +	loff_t max_size;
>  
>  	if (!ext4_has_feature_orphan_file(sb))
>  		return 0;
> @@ -589,8 +590,13 @@ int ext4_init_orphan_info(struct super_block *sb)
>  	 * This is just an artificial limit to prevent corrupted fs from
>  	 * consuming absurd amounts of memory when pinning blocks of orphan
>  	 * file in memory.
> +	 *
> +	 * e2fsprogs 1.47.4 produces 2MB orphan files by default regardless
> +	 * of the number of blocks so that's where the second limit comes from.
>  	 */
> -	if (inode->i_size > (EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits)) {
> +	max_size = max(EXT4_MAX_ORPHAN_FILE_BLOCKS << inode->i_blkbits,
> +		       2 << 20);
> +	if (inode->i_size > max_size) {
>  		ext4_msg(sb, KERN_ERR, "orphan file too big: %llu",
>  			 (unsigned long long)inode->i_size);
>  		ret = -EFSCORRUPTED;