Hi, I notice a regression report on Bugzilla [1]. Quoting from it: > Since commit a44be64, remounting a read-only ext4 filesystem to become read-write fails when quotas are enabled. The mount syscall returns -EROFS and outputs the following in dmesg: > > ``` > EXT4-fs warning (device loop0): ext4_enable_quotas:7028: Failed to enable quota tracking (type=0, err=-30, ino=3). Please run e2fsck > ``` > > > Root cause > > The problem can be traced back to the changes introduced in commit a44be64. It appears that the issue arises because the SB_RDONLY bit of the s_flags field is now only cleared after executing the ext4_enable_quotas function. However, the vfs_setup_quota_inode function, called by ext4_enable_quotas, checks whether this bit is set (fs/quota/dquot.c:2331): > > ``` > if (IS_RDONLY(inode)) > return -EROFS; > ``` > > This condition therefore always triggers the -EROFS fail condition. > > > Steps to Reproduce > > The bug can be reproduced by executing the following script on a current mainline kernel with defconfig: > > ``` > #!/bin/bash > > set -ex > > truncate -s 1G /tmp/img > mkfs.ext4 /tmp/img > tune2fs -Q usrquota,grpquota,prjquota /tmp/img > losetup /dev/loop0 /tmp/img > mount -o ro /dev/loop0 /mnt > mount -o remount,rw /mnt > ``` > > Executing the script results in the following output: > > ``` > + truncate -s 1G /tmp/img > + mkfs.ext4 /tmp/img > mke2fs 1.47.0 (5-Feb-2023) > Discarding device blocks: done > Creating filesystem with 262144 4k blocks and 65536 inodes > Filesystem UUID: b96a3da2-043f-11ee-b6f0-47c69db05231 > Superblock backups stored on blocks: > 32768, 98304, 163840, 229376 > > Allocating group tables: done > Writing inode tables: done > Creating journal (8192 blocks): done > Writing superblocks and filesystem accounting information: done > > + tune2fs -Q usrquota,grpquota,prjquota /tmp/img > tune2fs 1.47.0 (5-Feb-2023) > + losetup /dev/loop0 /tmp/img > [ 6.766763] loop0: detected capacity change from 0 to 2097152 > + mount -o ro /dev/loop0 /mnt > [ 6.791561] EXT4-fs (loop0): mounted filesystem b96a3da2-043f-11ee-b6f0-47c69db05231 ro with ordered data mode. Quota mode: journalled. > + mount -o remount,rw /mnt > [ 6.805546] EXT4-fs warning (device loop0): ext4_enable_quotas:7028: Failed to enable quota tracking (type=0, err=-30, ino=3). Please run e2fsck to fix. > mount: /mnt: cannot remount /dev/loop0 read-write, is write-protected. > dmesg(1) may have more information after failed mount system call. > ``` See Bugzilla for the full thread. Ted, it looks like this regression is caused by your ext4_xattr_block_set() fix to earlier syzbot report. Would you like to take a look on it? Anyway, I'm adding it to regzbot: #regzbot introduced: a44be64bbecb15 https://bugzilla.kernel.org/show_bug.cgi?id=217529 #regzbot title: Remounting ext4 filesystem from ro to rw fails when quotas are enabled Thanks. [1]: https://bugzilla.kernel.org/show_bug.cgi?id=217529 -- An old man doll... just what I always wanted! - Clara
