kernel.git/fs/quota, branch linux-6.5.y

quota: explicitly forbid quota files from being encrypted

2023-11-28T17:15:07Z

commit d3cc1b0be258191d6360c82ea158c2972f8d3991 upstream. Since commit d7e7b9af104c ("fscrypt: stop using keyrings subsystem for fscrypt_master_key"), xfstest generic/270 causes a WARNING when run on f2fs with test_dummy_encryption in the mount options: $ kvm-xfstests -c f2fs/encrypt generic/270 [...] WARNING: CPU: 1 PID: 2453 at fs/crypto/keyring.c:240 fscrypt_destroy_keyring+0x1f5/0x260 The cause of the WARNING is that not all encrypted inodes have been evicted before fscrypt_destroy_keyring() is called, which violates an assumption. This happens because the test uses an external quota file, which gets automatically encrypted due to test_dummy_encryption. Encryption of quota files has never really been supported. On ext4, ext4_quota_read() does not decrypt the data, so encrypted quota files are always considered invalid on ext4. On f2fs, f2fs_quota_read() uses the pagecache, so trying to use an encrypted quota file gets farther, resulting in the issue described above being possible. But this was never intended to be possible, and there is no use case for it. Therefore, make the quota support layer explicitly reject using IS_ENCRYPTED inodes when quotaon is attempted. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Jan Kara Message-Id: <20230905003227.326998-1-ebiggers@kernel.org> Signed-off-by: Greg Kroah-Hartman

quota: Fix slow quotaoff

2023-10-19T21:10:56Z

commit 869b6ea1609f655a43251bf41757aa44e5350a8f upstream. Eric has reported that commit dabc8b207566 ("quota: fix dqput() to follow the guarantees dquot_srcu should provide") heavily increases runtime of generic/270 xfstest for ext4 in nojournal mode. The reason for this is that ext4 in nojournal mode leaves dquots dirty until the last dqput() and thus the cleanup done in quota_release_workfn() has to write them all. Due to the way quota_release_workfn() is written this results in synchronize_srcu() call for each dirty dquot which makes the dquot cleanup when turning quotas off extremely slow. To be able to avoid synchronize_srcu() for each dirty dquot we need to rework how we track dquots to be cleaned up. Instead of keeping the last dquot reference while it is on releasing_dquots list, we drop it right away and mark the dquot with new DQ_RELEASING_B bit instead. This way we can we can remove dquot from releasing_dquots list when new reference to it is acquired and thus there's no need to call synchronize_srcu() each time we drop dq_list_lock. References: https://lore.kernel.org/all/ZRytn6CxFK2oECUt@debian-BULLSEYE-live-builder-AMD64 Reported-by: Eric Whitney Fixes: dabc8b207566 ("quota: fix dqput() to follow the guarantees dquot_srcu should provide") CC: stable@vger.kernel.org Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

quota: fix dqput() to follow the guarantees dquot_srcu should provide

2023-09-13T07:53:13Z

[ Upstream commit dabc8b20756601b9e1cc85a81d47d3f98ed4d13a ] The dquot_mark_dquot_dirty() using dquot references from the inode should be protected by dquot_srcu. quota_off code takes care to call synchronize_srcu(&dquot_srcu) to not drop dquot references while they are used by other users. But dquot_transfer() breaks this assumption. We call dquot_transfer() to drop the last reference of dquot and add it to free_dquots, but there may still be other users using the dquot at this time, as shown in the function graph below: cpu1 cpu2 _________________|_________________ wb_do_writeback CHOWN(1) ... ext4_da_update_reserve_space dquot_claim_block ... dquot_mark_dquot_dirty // try to dirty old quota test_bit(DQ_ACTIVE_B, &dquot->dq_flags) // still ACTIVE if (test_bit(DQ_MOD_B, &dquot->dq_flags)) // test no dirty, wait dq_list_lock ... dquot_transfer __dquot_transfer dqput_all(transfer_from) // rls old dquot dqput // last dqput dquot_release clear_bit(DQ_ACTIVE_B, &dquot->dq_flags) atomic_dec(&dquot->dq_count) put_dquot_last(dquot) list_add_tail(&dquot->dq_free, &free_dquots) // add the dquot to free_dquots if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) add dqi_dirty_list // add released dquot to dirty_list This can cause various issues, such as dquot being destroyed by dqcache_shrink_scan() after being added to free_dquots, which can trigger a UAF in dquot_mark_dquot_dirty(); or after dquot is added to free_dquots and then to dirty_list, it is added to free_dquots again after dquot_writeback_dquots() is executed, which causes the free_dquots list to be corrupted and triggers a UAF when dqcache_shrink_scan() is called for freeing dquot twice. As Honza said, we need to fix dquot_transfer() to follow the guarantees dquot_srcu should provide. But calling synchronize_srcu() directly from dquot_transfer() is too expensive (and mostly unnecessary). So we add dquot whose last reference should be dropped to the new global dquot list releasing_dquots, and then queue work item which would call synchronize_srcu() and after that perform the final cleanup of all the dquots on releasing_dquots. Fixes: 4580b30ea887 ("quota: Do not dirty bad dquots") Suggested-by: Jan Kara Signed-off-by: Baokun Li Signed-off-by: Jan Kara Message-Id: <20230630110822.3881712-5-libaokun1@huawei.com> Signed-off-by: Sasha Levin

quota: add new helper dquot_active()

2023-09-13T07:53:13Z

[ Upstream commit 33bcfafc48cb186bc4bbcea247feaa396594229e ] Add new helper function dquot_active() to make the code more concise. Signed-off-by: Baokun Li Signed-off-by: Jan Kara Message-Id: <20230630110822.3881712-4-libaokun1@huawei.com> Stable-dep-of: dabc8b207566 ("quota: fix dqput() to follow the guarantees dquot_srcu should provide") Signed-off-by: Sasha Levin

quota: rename dquot_active() to inode_quota_active()

2023-09-13T07:53:13Z

[ Upstream commit 4b9bdfa16535de8f49bf954aeed0f525ee2fc322 ] Now we have a helper function dquot_dirty() to determine if dquot has DQ_MOD_B bit. dquot_active() can easily be misunderstood as a helper function to determine if dquot has DQ_ACTIVE_B bit. So we avoid this by renaming it to inode_quota_active() and later on we will add the helper function dquot_active() to determine if dquot has DQ_ACTIVE_B bit. Signed-off-by: Baokun Li Signed-off-by: Jan Kara Message-Id: <20230630110822.3881712-3-libaokun1@huawei.com> Stable-dep-of: dabc8b207566 ("quota: fix dqput() to follow the guarantees dquot_srcu should provide") Signed-off-by: Sasha Levin

quota: factor out dquot_write_dquot()

2023-09-13T07:53:12Z

[ Upstream commit 024128477809f8073d870307c8157b8826ebfd08 ] Refactor out dquot_write_dquot() to reduce duplicate code. Signed-off-by: Baokun Li Signed-off-by: Jan Kara Message-Id: <20230630110822.3881712-2-libaokun1@huawei.com> Stable-dep-of: dabc8b207566 ("quota: fix dqput() to follow the guarantees dquot_srcu should provide") Signed-off-by: Sasha Levin

quota: fix warning in dqgrab()

2023-06-05T14:50:30Z

There's issue as follows when do fault injection: WARNING: CPU: 1 PID: 14870 at include/linux/quotaops.h:51 dquot_disable+0x13b7/0x18c0 Modules linked in: CPU: 1 PID: 14870 Comm: fsconfig Not tainted 6.3.0-next-20230505-00006-g5107a9c821af-dirty #541 RIP: 0010:dquot_disable+0x13b7/0x18c0 RSP: 0018:ffffc9000acc79e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88825e41b980 RDX: 0000000000000000 RSI: ffff88825e41b980 RDI: 0000000000000002 RBP: ffff888179f68000 R08: ffffffff82087ca7 R09: 0000000000000000 R10: 0000000000000001 R11: ffffed102f3ed026 R12: ffff888179f68130 R13: ffff888179f68110 R14: dffffc0000000000 R15: ffff888179f68118 FS: 00007f450a073740(0000) GS:ffff88882fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe96f2efd8 CR3: 000000025c8ad000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dquot_load_quota_sb+0xd53/0x1060 dquot_resume+0x172/0x230 ext4_reconfigure+0x1dc6/0x27b0 reconfigure_super+0x515/0xa90 __x64_sys_fsconfig+0xb19/0xd20 do_syscall_64+0x39/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd Above issue may happens as follows: ProcessA ProcessB ProcessC sys_fsconfig vfs_fsconfig_locked reconfigure_super ext4_remount dquot_suspend -> suspend all type quota sys_fsconfig vfs_fsconfig_locked reconfigure_super ext4_remount dquot_resume ret = dquot_load_quota_sb add_dquot_ref do_open -> open file O_RDWR vfs_open do_dentry_open get_write_access atomic_inc_unless_negative(&inode->i_writecount) ext4_file_open dquot_file_open dquot_initialize __dquot_initialize dqget atomic_inc(&dquot->dq_count); __dquot_initialize __dquot_initialize dqget if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) ext4_acquire_dquot -> Return error DQ_ACTIVE_B flag isn't set dquot_disable invalidate_dquots if (atomic_read(&dquot->dq_count)) dqgrab WARN_ON_ONCE(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) -> Trigger warning In the above scenario, 'dquot->dq_flags' has no DQ_ACTIVE_B is normal when dqgrab(). To solve above issue just replace the dqgrab() use in invalidate_dquots() with atomic_inc(&dquot->dq_count). Signed-off-by: Ye Bin Signed-off-by: Jan Kara Message-Id: <20230605140731.2427629-3-yebin10@huawei.com>

quota: Properly disable quotas when add_dquot_ref() fails

2023-06-05T14:50:30Z

When add_dquot_ref() fails (usually due to IO error or ENOMEM), we want to disable quotas we are trying to enable. However dquot_disable() call was passed just the flags we are enabling so in case flags == DQUOT_USAGE_ENABLED dquot_disable() call will just fail with EINVAL instead of properly disabling quotas. Fix the problem by always passing DQUOT_LIMITS_ENABLED | DQUOT_USAGE_ENABLED to dquot_disable() in this case. Reported-and-tested-by: Ye Bin Reported-by: syzbot+e633c79ceaecbf479854@syzkaller.appspotmail.com Signed-off-by: Jan Kara Message-Id: <20230605140731.2427629-2-yebin10@huawei.com>

fs: Drop wait_unfrozen wait queue

2023-05-30T13:36:40Z

wait_unfrozen waitqueue is used only in quota code to wait for filesystem to become unfrozen. In that place we can just use sb_start_write() - sb_end_write() pair to achieve the same. So just remove the waitqueue. Reviewed-by: Christian Brauner Message-Id: <20230525141710.7595-1-jack@suse.cz> Signed-off-by: Jan Kara

quota: mark PRINT_QUOTA_WARNING as BROKEN

2023-04-14T11:06:50Z

PRINT_QUOTA_WARNING is deprecated since commit 8e8934695dfd ("quota: send messages via netlink") merged in 2007. Users should rather be using notification over netlink socket if they are interested about explicit notification in addition to plain EDQUOT error. Since printing to console from deep inside filesystem code is problematic, mark the feature as BROKEN now and see who complains. Signed-off-by: Yangtao Li Signed-off-by: Jan Kara Message-Id: <20230413163833.43913-1-frank.li@vivo.com>