Hello, Commit 7dac4a1726a9 ("ext4: add validity checks for bitmap block numbers") in 4.17-rc1 causes a regression on ext3 with a custom stride-size. One of the new checks triggers, sometimes leading to transient -ENOSPC errors that go away after a remount. Trivially reproduced with: $ mkfs -t ext3 -E stride=256 /dev/vdb $ mount /dev/vdb /mnt $ cd /mnt $ wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.16.3.tar.xz $ tar xvf linux-4.16.3.tar.xz [ 2769.383365] EXT4-fs (vdb): mounting ext3 file system using the ext4 subsystem [ 2769.392635] EXT4-fs (vdb): mounted filesystem with ordered data mode. Opts: (null) [ 2791.127834] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 14: block 462848: invalid block bitmap [ 2791.130456] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 15: block 495872: invalid block bitmap [ 2791.133257] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 16: block 528896: invalid block bitmap [ 2791.137147] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 17: block 561920: invalid block bitmap [ 2791.139943] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 18: block 594944: invalid block bitmap [ 2791.142342] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 20: block 660992: invalid block bitmap [ 2791.145348] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 21: block 694016: invalid block bitmap [ 2791.148161] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 22: block 727040: invalid block bitmap [ 2791.150702] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 23: block 760064: invalid block bitmap [ 2791.153333] EXT4-fs error (device vdb): ext4_validate_block_bitmap:399: comm tar: bg 24: block 793088: invalid block bitmap Reverting 7dac4a1726a9 fixes it for me. Thanks, Ilya