blaster4385/linux-IllusionX/fs/ext4, branch v6.12.1

ext4: fix off by one issue in alloc_flex_gd()

2024-10-04T21:36:28Z

Wesley reported an issue: ================================================================== EXT4-fs (dm-5): resizing filesystem from 7168 to 786432 blocks ------------[ cut here ]------------ kernel BUG at fs/ext4/resize.c:324! CPU: 9 UID: 0 PID: 3576 Comm: resize2fs Not tainted 6.11.0+ #27 RIP: 0010:ext4_resize_fs+0x1212/0x12d0 Call Trace: __ext4_ioctl+0x4e0/0x1800 ext4_ioctl+0x12/0x20 __x64_sys_ioctl+0x99/0xd0 x64_sys_call+0x1206/0x20d0 do_syscall_64+0x72/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e ================================================================== While reviewing the patch, Honza found that when adjusting resize_bg in alloc_flex_gd(), it was possible for flex_gd->resize_bg to be bigger than flexbg_size. The reproduction of the problem requires the following: o_group = flexbg_size * 2 * n; o_size = (o_group + 1) * group_size; n_group: [o_group + flexbg_size, o_group + flexbg_size * 2) o_size = (n_group + 1) * group_size; Take n=0,flexbg_size=16 as an example: last:15 |o---------------|--------------n-| o_group:0 resize to n_group:30 The corresponding reproducer is: img=test.img rm -f $img truncate -s 600M $img mkfs.ext4 -F $img -b 1024 -G 16 8M dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 248M Delete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE() to prevent the issue from happening again. [ Note: another reproucer which this commit fixes is: img=test.img rm -f $img truncate -s 25MiB $img mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img truncate -s 3GiB $img dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 3G umount $dev losetup -d $dev -- TYT ] Reported-by: Wesley Hershberger Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2081231 Reported-by: Stéphane Graber Closes: https://lore.kernel.org/all/20240925143325.518508-1-aleksandr.mikhalitsyn@canonical.com/ Tested-by: Alexander Mikhalitsyn Tested-by: Eric Sandeen Fixes: 665d3e0af4d3 ("ext4: reduce unnecessary memory allocation in alloc_flex_gd()") Cc: stable@vger.kernel.org Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://patch.msgid.link/20240927133329.1015041-1-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: mark fc as ineligible using an handle in ext4_xattr_set()

2024-10-04T21:36:09Z

Calling ext4_fc_mark_ineligible() with a NULL handle is racy and may result in a fast-commit being done before the filesystem is effectively marked as ineligible. This patch moves the call to this function so that an handle can be used. If a transaction fails to start, then there's not point in trying to mark the filesystem as ineligible, and an error will eventually be returned to user-space. Suggested-by: Jan Kara Signed-off-by: Luis Henriques (SUSE) Reviewed-by: Jan Kara Link: https://patch.msgid.link/20240923104909.18342-3-luis.henriques@linux.dev Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

ext4: use handle to mark fc as ineligible in __track_dentry_update()

2024-10-04T21:35:54Z

Calling ext4_fc_mark_ineligible() with a NULL handle is racy and may result in a fast-commit being done before the filesystem is effectively marked as ineligible. This patch fixes the calls to this function in __track_dentry_update() by adding an extra parameter to the callback used in ext4_fc_track_template(). Suggested-by: Jan Kara Signed-off-by: Luis Henriques (SUSE) Reviewed-by: Jan Kara Link: https://patch.msgid.link/20240923104909.18342-2-luis.henriques@linux.dev Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36Z

Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.

Merge tag 'ext4_for_linus-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2024-09-21T02:26:45Z

Pull ext4 updates from Ted Ts'o: "Lots of cleanups and bug fixes this cycle, primarily in the block allocation, extent management, fast commit, and journalling" * tag 'ext4_for_linus-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (93 commits) ext4: convert EXT4_B2C(sbi->s_stripe) users to EXT4_NUM_B2C ext4: check stripe size compatibility on remount as well ext4: fix i_data_sem unlock order in ext4_ind_migrate() ext4: remove the special buffer dirty handling in do_journal_get_write_access ext4: fix a potential assertion failure due to improperly dirtied buffer ext4: hoist ext4_block_write_begin and replace the __block_write_begin ext4: persist the new uptodate buffers in ext4_journalled_zero_new_buffers ext4: dax: keep orphan list before truncate overflow allocated blocks ext4: fix error message when rejecting the default hash ext4: save unnecessary indentation in ext4_ext_create_new_leaf() ext4: make some fast commit functions reuse extents path ext4: refactor ext4_swap_extents() to reuse extents path ext4: get rid of ppath in convert_initialized_extent() ext4: get rid of ppath in ext4_ext_handle_unwritten_extents() ext4: get rid of ppath in ext4_ext_convert_to_initialized() ext4: get rid of ppath in ext4_convert_unwritten_extents_endio() ext4: get rid of ppath in ext4_split_convert_extents() ext4: get rid of ppath in ext4_split_extent() ext4: get rid of ppath in ext4_force_split_extent_at() ext4: get rid of ppath in ext4_split_extent_at() ...

Merge tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-09-16T07:14:02Z

Pull vfs file updates from Christian Brauner: "This is the work to cleanup and shrink struct file significantly. Right now, (focusing on x86) struct file is 232 bytes. After this series struct file will be 184 bytes aka 3 cacheline and a spare 8 bytes for future extensions at the end of the struct. With struct file being as ubiquitous as it is this should make a difference for file heavy workloads and allow further optimizations in the future. - struct fown_struct was embedded into struct file letting it take up 32 bytes in total when really it shouldn't even be embedded in struct file in the first place. Instead, actual users of struct fown_struct now allocate the struct on demand. This frees up 24 bytes. - Move struct file_ra_state into the union containg the cleanup hooks and move f_iocb_flags out of the union. This closes a 4 byte hole we created earlier and brings struct file to 192 bytes. Which means struct file is 3 cachelines and we managed to shrink it by 40 bytes. - Reorder struct file so that nothing crosses a cacheline. I suspect that in the future we will end up reordering some members to mitigate false sharing issues or just because someone does actually provide really good perf data. - Shrinking struct file to 192 bytes is only part of the work. Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache is created with SLAB_TYPESAFE_BY_RCU the free pointer must be located outside of the object because the cache doesn't know what part of the memory can safely be overwritten as it may be needed to prevent object recycling. That has the consequence that SLAB_TYPESAFE_BY_RCU may end up adding a new cacheline. So this also contains work to add a new kmem_cache_create_rcu() function that allows the caller to specify an offset where the freelist pointer is supposed to be placed. Thus avoiding the implicit addition of a fourth cacheline. - And finally this removes the f_version member in struct file. The f_version member isn't particularly well-defined. It is mainly used as a cookie to detect concurrent seeks when iterating directories. But it is also abused by some subsystems for completely unrelated things. It is mostly a directory and filesystem specific thing that doesn't really need to live in struct file and with its wonky semantics it really lacks a specific function. For pipes, f_version is (ab)used to defer poll notifications until a write has happened. And struct pipe_inode_info is used by multiple struct files in their ->private_data so there's no chance of pushing that down into file->private_data without introducing another pointer indirection. But pipes don't rely on f_pos_lock so this adds a union into struct file encompassing f_pos_lock and a pipe specific f_pipe member that pipes can use. This union of course can be extended to other file types and is similar to what we do in struct inode already" * tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits) fs: remove f_version pipe: use f_pipe fs: add f_pipe ubifs: store cookie in private data ufs: store cookie in private data udf: store cookie in private data proc: store cookie in private data ocfs2: store cookie in private data input: remove f_version abuse ext4: store cookie in private data ext2: store cookie in private data affs: store cookie in private data fs: add generic_llseek_cookie() fs: use must_set_pos() fs: add must_set_pos() fs: add vfs_setpos_cookie() s390: remove unused f_version ceph: remove unused f_version adi: remove unused f_version mm: Removed @freeptr_offset to prevent doc warning ...

ext4: store cookie in private data

2024-09-09T09:58:08Z

Store the cookie to detect concurrent seeks on directories in file->private_data. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-11-6d3e4816aa7b@kernel.org Acked-by: Theodore Ts'o Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

ext4: convert EXT4_B2C(sbi->s_stripe) users to EXT4_NUM_B2C

2024-09-04T02:14:17Z

Although we have checks to make sure s_stripe is a multiple of cluster size, in case we accidentally end up with a scenario where this is not the case, use EXT4_NUM_B2C() so that we don't end up with unexpected cases where EXT4_B2C(stripe) becomes 0. Also make the is_stripe_aligned check in regular_allocator a bit more robust while we are at it. This should ideally have no functional change unless we have a bug somewhere causing (stripe % cluster_size != 0) Reviewed-by: Kemeng Shi Signed-off-by: Ojaswin Mujoo Reviewed-by: Ritesh Harjani (IBM) Link: https://patch.msgid.link/e0c0a3b58a40935a1361f668851d041575861411.1725002410.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o

ext4: check stripe size compatibility on remount as well

2024-09-04T02:14:17Z

We disable stripe size in __ext4_fill_super if it is not a multiple of the cluster ratio however this check is missed when trying to remount. This can leave us with cases where stripe < cluster_ratio after remount:set making EXT4_B2C(sbi->s_stripe) become 0 that can cause some unforeseen bugs like divide by 0. Fix that by adding the check in remount path as well. Reported-by: syzbot+1ad8bac5af24d01e2cbd@syzkaller.appspotmail.com Tested-by: syzbot+1ad8bac5af24d01e2cbd@syzkaller.appspotmail.com Reviewed-by: Kemeng Shi Reviewed-by: Ritesh Harjani (IBM) Fixes: c3defd99d58c ("ext4: treat stripe in block unit") Signed-off-by: Ojaswin Mujoo Link: https://patch.msgid.link/3a493bb503c3598e25dcfbed2936bb2dff3fece7.1725002410.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o

ext4: fix i_data_sem unlock order in ext4_ind_migrate()

2024-09-04T02:14:17Z

Fuzzing reports a possible deadlock in jbd2_log_wait_commit. This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require synchronous updates because the file descriptor is opened with O_SYNC. This can lead to the jbd2_journal_stop() function calling jbd2_might_wait_for_commit(), potentially causing a deadlock if the EXT4_IOC_MIGRATE call races with a write(2) system call. This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the jbd2_journal_stop function while i_data_sem is locked. This triggers lockdep because the jbd2_journal_start function might also lock the same jbd2_handle simultaneously. Found by Linux Verification Center (linuxtesting.org) with syzkaller. Reviewed-by: Ritesh Harjani (IBM) Co-developed-by: Mikhail Ukhin Signed-off-by: Mikhail Ukhin Signed-off-by: Artem Sadovnikov Rule: add Link: https://lore.kernel.org/stable/20240404095000.5872-1-mish.uxin2012%40yandex.ru Link: https://patch.msgid.link/20240829152210.2754-1-ancowi69@gmail.com Signed-off-by: Theodore Ts'o