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2024-09-04fuse: allow idmapped mountsAlexander Mikhalitsyn1-3/+9
Now we have everything in place and we can allow idmapped mounts by setting the FS_ALLOW_IDMAP flag. Notice that real availability of idmapped mounts will depend on the fuse daemon. Fuse daemon have to set FUSE_ALLOW_IDMAP flag in the FUSE_INIT reply. To discuss: - we enable idmapped mounts support only if "default_permissions" mode is enabled, because otherwise we would need to deal with UID/GID mappings in the userspace side OR provide the userspace with idmapped req->in.h.uid/req->in.h.gid values which is not something that we probably want to. Idmapped mounts philosophy is not about faking caller uid/gid. Some extra links and examples: - libfuse support https://github.com/mihalicyn/libfuse/commits/idmap_support - fuse-overlayfs support: https://github.com/mihalicyn/fuse-overlayfs/commits/idmap_support - cephfs-fuse conversion example https://github.com/mihalicyn/ceph/commits/fuse_idmap - glusterfs conversion example https://github.com/mihalicyn/glusterfs/commits/fuse_idmap Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: warn if fuse_access is called when idmapped mounts are allowedAlexander Mikhalitsyn1-0/+8
It is not possible with the current fuse code, but let's protect ourselves from regressions in the future. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: handle idmappings properly in ->write_iter()Alexander Mikhalitsyn1-1/+2
This is needed to properly clear suid/sgid. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmapped ->rename opAlexander Mikhalitsyn1-4/+5
RENAME_WHITEOUT is a special case of ->rename and we need to take idmappings into account there. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmapped ->set_aclAlexander Mikhalitsyn1-2/+2
It's just a matter of adjusting a permission check condition for S_ISGID flag. All the rest is already handled in the generic VFS code. Notice that this permission check is the analog of what we have in posix_acl_update_mode() generic helper, but fuse doesn't use this helper as on the kernel side we don't care about ensuring that POSIX ACL and CHMOD permissions are in sync as it is a responsibility of a userspace daemon to handle that. For the same reason we don't have a calls to posix_acl_chmod(), while most of other filesystem do. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: drop idmap argument from __fuse_get_aclAlexander Mikhalitsyn1-4/+2
We don't need to have idmap in the __fuse_get_acl as we don't have any use for it. In the current POSIX ACL implementation, idmapped mounts are taken into account on the userspace/kernel border (see vfs_set_acl_idmapped_mnt() and vfs_posix_acl_to_xattr()). Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmapped ->setattr opAlexander Mikhalitsyn3-14/+26
Need to translate uid and gid in case of chown(2). Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmapped ->permission inode opAlexander Mikhalitsyn1-2/+2
We only cover the case when "default_permissions" flag is used. A reason for that is that otherwise all the permission checks are done in the userspace and we have to deal with VFS idmapping in the userspace (which is bad), alternatively we have to provide the userspace with idmapped req->in.h.uid/req->in.h.gid which is also not align with VFS idmaps philosophy. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmapped getattr inode opAlexander Mikhalitsyn1-20/+24
We have to: - pass an idmapping to the generic_fillattr() to properly handle UIG/GID mapping for the userspace. - pass -/- to fuse_fillattr() (analog of generic_fillattr() in fuse). Difference between these two is that generic_fillattr() takes all the stat() data from the inode directly, while fuse_fillattr() codepath takes a fresh data just from the userspace reply on the FUSE_GETATTR request. In some cases we can just pass &nop_mnt_idmap, because idmapping won't be used in these codepaths. For example, when 3rd argument of fuse_do_getattr() is NULL then idmap argument is not used. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmap for mkdir/mknod/symlink/create/tmpfileAlexander Mikhalitsyn1-18/+20
We have all the infrastructure in place, we just need to pass an idmapping here. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: support idmapped FUSE_EXT_GROUPSAlexander Mikhalitsyn1-7/+12
We don't need to remap parent_gid, but have to adjust group membership checks and take idmapping into account. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: add an idmap argument to fuse_simple_requestAlexander Mikhalitsyn9-44/+47
If idmap == NULL *and* filesystem daemon declared idmapped mounts support, then uid/gid values in a fuse header will be -1. No functional changes intended. Signed-off-by: Alexander Mikhalitsyn <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04fuse: add basic infrastructure to support idmappingsAlexander Mikhalitsyn2-12/+39
Add some preparational changes in fuse_get_req/fuse_force_creds to handle idmappings. Miklos suggested [1], [2] to change the meaning of in.h.uid/in.h.gid fields when daemon declares support for idmapped mounts. In a new semantic, we fill uid/gid values in fuse header with a id-mapped caller uid/gid (for requests which create new inodes), for all the rest cases we just send -1 to userspace. No functional changes intended. Link: https://lore.kernel.org/all/CAJfpegsVY97_5mHSc06mSw79FehFWtoXT=hhTUK_E-Yhr7OAuQ@mail.gmail.com/ [1] Link: https://lore.kernel.org/all/CAJfpegtHQsEUuFq1k4ZbTD3E1h-GsrN3PWyv7X8cg6sfU_W2Yw@mail.gmail.com/ [2] Signed-off-by: Alexander Mikhalitsyn <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04namespace: introduce SB_I_NOIDMAP flagAlexander Mikhalitsyn1-0/+4
Right now we determine if filesystem support vfs idmappings or not basing on the FS_ALLOW_IDMAP flag presence. This "static" way works perfecly well for local filesystems like ext4, xfs, btrfs, etc. But for network-like filesystems like fuse, cephfs this approach is not ideal, because sometimes proper support of vfs idmaps requires some extensions for the on-wire protocol, which implies that changes have to be made not only in the Linux kernel code but also in the 3rd party components like libfuse, cephfs MDS server and so on. We have seen that issue during our work on cephfs idmapped mounts [1] with Christian, but right now I'm working on the idmapped mounts support for fuse/virtiofs and I think that it is a right time for this extension. [1] 5ccd8530dd7 ("ceph: handle idmapped mounts in create_request_message()") Suggested-by: Christian Brauner <[email protected]> Signed-off-by: Alexander Mikhalitsyn <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]>
2024-09-04proc: Add nbcon support for /proc/consolesJohn Ogness1-2/+3
Update /proc/consoles output to show 'W' if an nbcon console is registered. Since the write_thread() callback is mandatory, it enough just to check if it is an nbcon console. Also update /proc/consoles output to show 'N' if it is an nbcon console. Signed-off-by: John Ogness <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Petr Mladek <[email protected]>
2024-09-04proc: consoles: Add notation to c_start/c_stopJohn Ogness1-0/+2
fs/proc/consoles.c:78:13: warning: context imbalance in 'c_start' - wrong count at exit fs/proc/consoles.c:104:13: warning: context imbalance in 'c_stop' - unexpected unlock Signed-off-by: John Ogness <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Petr Mladek <[email protected]>
2024-09-04mm: use ARCH_PKEY_BITS to define VM_PKEY_BITNJoey Gouly1-0/+2
Use the new CONFIG_ARCH_PKEY_BITS to simplify setting these bits for different architectures. Signed-off-by: Joey Gouly <[email protected]> Cc: Andrew Morton <[email protected]> Cc: [email protected] Cc: [email protected] Acked-by: Dave Hansen <[email protected]> Reviewed-by: Anshuman Khandual <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Will Deacon <[email protected]>
2024-09-03x86: remove PG_uncachedMatthew Wilcox (Oracle)1-5/+3
Convert x86 to use PG_arch_2 instead of PG_uncached and remove PG_uncached. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-09-03mm: rename PG_mappedtodisk to PG_owner_2Matthew Wilcox (Oracle)1-1/+1
This flag has similar constraints to PG_owner_priv_1 -- it is ignored by core code, and is entirely for the use of the code which allocated the folio. Since the pagecache does not use it, individual filesystems can use it. The bufferhead code does use it, so filesystems which use the buffer cache must not use it for another purpose. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-09-03mm: introduce page_mapcount_is_type()Matthew Wilcox (Oracle)1-2/+1
Resolve the awkward "and add one to this opaque constant" test into a self-documenting inline function. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Acked-by: David Hildenbrand <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Kent Overstreet <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-09-03ext4: convert EXT4_B2C(sbi->s_stripe) users to EXT4_NUM_B2COjaswin Mujoo1-5/+7
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 <[email protected]> Signed-off-by: Ojaswin Mujoo <[email protected]> Reviewed-by: Ritesh Harjani (IBM) <[email protected]> Link: https://patch.msgid.link/e0c0a3b58a40935a1361f668851d041575861411.1725002410.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: check stripe size compatibility on remount as wellOjaswin Mujoo1-7/+22
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: [email protected] Tested-by: [email protected] Reviewed-by: Kemeng Shi <[email protected]> Reviewed-by: Ritesh Harjani (IBM) <[email protected]> Fixes: c3defd99d58c ("ext4: treat stripe in block unit") Signed-off-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/3a493bb503c3598e25dcfbed2936bb2dff3fece7.1725002410.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: fix i_data_sem unlock order in ext4_ind_migrate()Artem Sadovnikov1-1/+1
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) <[email protected]> Co-developed-by: Mikhail Ukhin <[email protected]> Signed-off-by: Mikhail Ukhin <[email protected]> Signed-off-by: Artem Sadovnikov <[email protected]> Rule: add Link: https://lore.kernel.org/stable/20240404095000.5872-1-mish.uxin2012%40yandex.ru Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: remove the special buffer dirty handling in do_journal_get_write_accessShida Zhang1-17/+1
This kinda revert the commit 56d35a4cd13e("ext4: Fix dirtying of journalled buffers in data=journal mode") made by Jan 14 years ago, since the do_get_write_access() itself can deal with the extra unexpected buf dirting things in a proper way now. Suggested-by: Jan Kara <[email protected]> Signed-off-by: Shida Zhang <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: fix a potential assertion failure due to improperly dirtied bufferShida Zhang3-12/+40
On an old kernel version(4.19, ext3, data=journal, pagesize=64k), an assertion failure will occasionally be triggered by the line below: ----------- jbd2_journal_commit_transaction { ... J_ASSERT_BH(bh, !buffer_dirty(bh)); /* * The buffer on BJ_Forget list and not jbddirty means ... } ----------- The same condition may also be applied to the lattest kernel version. When blocksize < pagesize and we truncate a file, there can be buffers in the mapping tail page beyond i_size. These buffers will be filed to transaction's BJ_Forget list by ext4_journalled_invalidatepage() during truncation. When the transaction doing truncate starts committing, we can grow the file again. This calls __block_write_begin() which allocates new blocks under these buffers in the tail page we go through the branch: if (buffer_new(bh)) { clean_bdev_bh_alias(bh); if (folio_test_uptodate(folio)) { clear_buffer_new(bh); set_buffer_uptodate(bh); mark_buffer_dirty(bh); continue; } ... } Hence buffers on BJ_Forget list of the committing transaction get marked dirty and this triggers the jbd2 assertion. Teach ext4_block_write_begin() to properly handle files with data journalling by avoiding dirtying them directly. Instead of folio_zero_new_buffers() we use ext4_journalled_zero_new_buffers() which takes care of handling journalling. We also don't need to mark new uptodate buffers as dirty in ext4_block_write_begin(). That will be either done either by block_commit_write() in case of success or by folio_zero_new_buffers() in case of failure. Reported-by: Baolin Liu <[email protected]> Suggested-by: Jan Kara <[email protected]> Signed-off-by: Shida Zhang <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: hoist ext4_block_write_begin and replace the __block_write_beginShida Zhang3-24/+12
Using __block_write_begin() make it inconvenient to journal the user data dirty process. We can't tell the block layer maintainer, ‘Hey, we want to trace the dirty user data in ext4, can we add some special code for ext4 in __block_write_begin?’:P So use ext4_block_write_begin() instead. The two functions are basically doing the same thing except for the fscrypt related code. Remove the unnecessary #ifdef since fscrypt_inode_uses_fs_layer_crypto() returns false (and it's known at compile time) when !CONFIG_FS_ENCRYPTION. And hoist the ext4_block_write_begin so that it can be used in other files. Suggested-by: Jan Kara <[email protected]> Suggested-by: Eric Biggers <[email protected]> Signed-off-by: Shida Zhang <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: persist the new uptodate buffers in ext4_journalled_zero_new_buffersShida Zhang1-1/+1
For new uptodate buffers we also need to call write_end_fn() to persist the uptodate content, similarly as folio_zero_new_buffers() does it. Suggested-by: Jan Kara <[email protected]> Signed-off-by: Shida Zhang <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: dax: keep orphan list before truncate overflow allocated blocksyangerkun1-6/+6
Any extending write for ext4 requires the inode to be placed on the orphan list before the actual write. In addition, the inode can be actually removed from the orphan list only after all writes are completed. Otherwise we'd leave allocated blocks beyond i_disksize if we could not copy all the data into allocated block and e2fsck would complain. Currently, direct IO and buffered IO comply with this logic(buffered IO will truncate all overflow allocated blocks that has not been written successfully, and direct IO will truncate all allocated blocks when error occurs). However, dax write break this since dax write will remove the inode from the orphan list by calling ext4_handle_inode_extension unconditionally during extending write. We add a argument to help determine does we do a fully write, and for the case not fully write, we leave the inode on the orphan list, and the latter ext4_inode_extension_cleanup will help us truncate the overflow allocated blocks, and then remove the inode from the orphan list. Signed-off-by: yangerkun <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: fix error message when rejecting the default hashGabriel Krisman Bertazi2-10/+18
Commit 985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") properly rejects volumes where s_def_hash_version is set to DX_HASH_SIPHASH, but the check and the error message should not look into casefold setup - a filesystem should never have DX_HASH_SIPHASH as the default hash. Fix it and, since we are there, move the check to ext4_hash_info_init. Fixes:985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") Signed-off-by: Gabriel Krisman Bertazi <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: save unnecessary indentation in ext4_ext_create_new_leaf()Baokun Li1-23/+21
Save an indentation level in ext4_ext_create_new_leaf() by removing unnecessary 'else'. Besides, the variable 'ee_block' is declared to avoid line breaks. No functional changes. Suggested-by: Jan Kara <[email protected]> Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: make some fast commit functions reuse extents pathBaokun Li2-33/+29
The ext4_find_extent() can update the extent path so that it does not have to allocate and free the path repeatedly, thus reducing the consumption of memory allocation and freeing in the following functions: ext4_ext_clear_bb ext4_ext_replay_set_iblocks ext4_fc_replay_add_range ext4_fc_set_bitmaps_and_counters No functional changes. Note that ext4_find_extent() does not support error pointers, so in this case set path to NULL first. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: refactor ext4_swap_extents() to reuse extents pathBaokun Li1-26/+22
The ext4_find_extent() can update the extent path so it doesn't have to allocate and free path repeatedly, thus reducing the consumption of memory allocation and freeing in ext4_swap_extents(). Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in convert_initialized_extent()Baokun Li1-18/+19
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in convert_initialized_extent(), the following is done here: * Free the extents path when an error is encountered. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_ext_handle_unwritten_extents()Baokun Li1-45/+37
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_ext_handle_unwritten_extents(), the following is done here: * Free the extents path when an error is encountered. * The 'allocated' is changed from passing a value to passing an address. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_ext_convert_to_initialized()Baokun Li1-38/+35
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_ext_convert_to_initialized(), the following is done here: * Free the extents path when an error is encountered. * Its caller needs to update ppath if it uses ppath. * The 'allocated' is changed from passing a value to passing an address. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_convert_unwritten_extents_endio()Baokun Li1-20/+23
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_convert_unwritten_extents_endio(), the following is done here: * Free the extents path when an error is encountered. * Its caller needs to update ppath if it uses ppath. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_split_convert_extents()Baokun Li1-32/+33
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_split_convert_extents(), the following is done here: * Its caller needs to update ppath if it uses ppath. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_split_extent()Baokun Li1-47/+50
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_split_extent(), the following is done here: * The 'allocated' is changed from passing a value to passing an address. * Its caller needs to update ppath if it uses ppath. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_force_split_extent_at()Baokun Li1-31/+38
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_force_split_extent_at(), the following is done here: * Free the extents path when an error is encountered. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_split_extent_at()Baokun Li1-38/+47
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_split_extent_at(), the following is done here: * Free the extents path when an error is encountered. * Its caller needs to update ppath if it uses ppath. * Teach ext4_ext_show_leaf() to skip error pointer. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_ext_insert_extent()Baokun Li4-47/+61
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_ext_insert_extent(), the following is done here: * Free the extents path when an error is encountered. * Its caller needs to update ppath if it uses ppath. * Free path when npath is used, free npath when it is not used. * The got_allocated_blocks label in ext4_ext_map_blocks() does not update err now, so err is updated to 0 if the err returned by ext4_ext_search_right() is greater than 0 and is about to enter got_allocated_blocks. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_ext_create_new_leaf()Baokun Li1-21/+22
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_ext_create_new_leaf(), the following is done here: * Free the extents path when an error is encountered. * Its caller needs to update ppath if it uses ppath. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in get_ext_path()Baokun Li2-19/+20
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. After getting rid of ppath in get_ext_path(), its caller may pass an error pointer to ext4_free_ext_path(), so it needs to teach ext4_free_ext_path() and ext4_ext_drop_refs() to skip the error pointer. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: get rid of ppath in ext4_find_extent()Baokun Li3-30/+34
The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. Getting rid of ppath in ext4_find_extent() requires its caller to update ppath. These ppaths will also be dropped later. No functional changes. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: propagate errors from ext4_find_extent() in ext4_insert_range()Baokun Li1-0/+1
Even though ext4_find_extent() returns an error, ext4_insert_range() still returns 0. This may confuse the user as to why fallocate returns success, but the contents of the file are not as expected. So propagate the error returned by ext4_find_extent() to avoid inconsistencies. Fixes: 331573febb6a ("ext4: Add support FALLOC_FL_INSERT_RANGE for fallocate") Cc: [email protected] Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: add new ext4_ext_path_brelse() helperBaokun Li1-12/+12
Add ext4_ext_path_brelse() helper function to reduce duplicate code and ensure that path->p_bh is set to NULL after it is released. Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: fix double brelse() the buffer of the extents pathBaokun Li1-0/+1
In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been released, otherwise it may be released twice. An example of what triggers this is as follows: split2 map split1 |--------|-------|--------| ext4_ext_map_blocks ext4_ext_handle_unwritten_extents ext4_split_convert_extents // path->p_depth == 0 ext4_split_extent // 1. do split1 ext4_split_extent_at |ext4_ext_insert_extent | ext4_ext_create_new_leaf | ext4_ext_grow_indepth | le16_add_cpu(&neh->eh_depth, 1) | ext4_find_extent | // return -ENOMEM |// get error and try zeroout |path = ext4_find_extent | path->p_depth = 1 |ext4_ext_try_to_merge | ext4_ext_try_to_merge_up | path->p_depth = 0 | brelse(path[1].p_bh) ---> not set to NULL here |// zeroout success // 2. update path ext4_find_extent // 3. do split2 ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth le16_add_cpu(&neh->eh_depth, 1) ext4_find_extent path[0].p_bh = NULL; path->p_depth = 1 read_extent_tree_block ---> return err // path[1].p_bh is still the old value ext4_free_ext_path ext4_ext_drop_refs // path->p_depth == 1 brelse(path[1].p_bh) ---> brelse a buffer twice Finally got the following WARRNING when removing the buffer from lru: ============================================ VFS: brelse: Trying to free free buffer WARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90 CPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716 RIP: 0010:__brelse+0x58/0x90 Call Trace: <TASK> __find_get_block+0x6e7/0x810 bdev_getblk+0x2b/0x480 __ext4_get_inode_loc+0x48a/0x1240 ext4_get_inode_loc+0xb2/0x150 ext4_reserve_inode_write+0xb7/0x230 __ext4_mark_inode_dirty+0x144/0x6a0 ext4_ext_insert_extent+0x9c8/0x3230 ext4_ext_map_blocks+0xf45/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ============================================ Fixes: ecb94f5fdf4b ("ext4: collapse a single extent tree block into the inode if possible") Cc: [email protected] Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-freeBaokun Li1-11/+10
When calling ext4_force_split_extent_at() in ext4_ext_replay_update_ex(), the 'ppath' is updated but it is the 'path' that is freed, thus potentially triggering a double-free in the following process: ext4_ext_replay_update_ex ppath = path ext4_force_split_extent_at(&ppath) ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path) ---> path First freed *orig_path = path = NULL ---> null ppath kfree(path) ---> path double-free !!! So drop the unnecessary ppath and use path directly to avoid this problem. And use ext4_find_extent() directly to update path, avoiding unnecessary memory allocation and freeing. Also, propagate the error returned by ext4_find_extent() instead of using strange error codes. Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Cc: [email protected] Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Ojaswin Mujoo <[email protected]> Tested-by: Ojaswin Mujoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: aovid use-after-free in ext4_ext_insert_extent()Baokun Li1-0/+1
As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr ================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...] Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ================================================================== So use *ppath to update the path to avoid the above problem. Reported-by: Ojaswin Mujoo <[email protected]> Closes: https://lore.kernel.org/r/[email protected] Fixes: 10809df84a4d ("ext4: teach ext4_ext_find_extent() to realloc path if necessary") Cc: [email protected] Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
2024-09-03ext4: update orig_path in ext4_find_extent()Baokun Li2-2/+2
In ext4_find_extent(), if the path is not big enough, we free it and set *orig_path to NULL. But after reallocating and successfully initializing the path, we don't update *orig_path, in which case the caller gets a valid path but a NULL ppath, and this may cause a NULL pointer dereference or a path memory leak. For example: ext4_split_extent path = *ppath = 2000 ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path = 2000); *orig_path = path = NULL; path = kcalloc() = 3000 ext4_split_extent_at(*ppath = NULL) path = *ppath; ex = path[depth].p_ext; // NULL pointer dereference! ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000010 CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847 RIP: 0010:ext4_split_extent_at+0x6d/0x560 Call Trace: <TASK> ext4_split_extent.isra.0+0xcb/0x1b0 ext4_ext_convert_to_initialized+0x168/0x6c0 ext4_ext_handle_unwritten_extents+0x325/0x4d0 ext4_ext_map_blocks+0x520/0xdb0 ext4_map_blocks+0x2b0/0x690 ext4_iomap_begin+0x20e/0x2c0 [...] ================================================================== Therefore, *orig_path is updated when the extent lookup succeeds, so that the caller can safely use path or *ppath. Fixes: 10809df84a4d ("ext4: teach ext4_ext_find_extent() to realloc path if necessary") Cc: [email protected] Signed-off-by: Baokun Li <[email protected]> Reviewed-by: Jan Kara <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>